it seems good training for a scientist to always read accounts of science with a critical filter primed to notice figurative language and to check that the communication can be understood in a non-metaphorical way
When water is poured from a bottle or other container the stream of liquid can take up complex shapes. In particular, it has long been noted how the stream can appear to have the shape of a chain or string of beads, with the flow seeming to be wider in some places that others.
A stream of poured water does not form a perfect cylinder – something that physics should be able to explain.
(Image by tookapic from Pixabay)
This is just the kind of thing that physicists think they should be able to explain…using physics. An article in Physics World (Jarman, 2022) reports some recent work on just this outstanding problem,
"If you pour water out of a bottle, the liquid stream will often adopt a chain-like structure….At the heart of the effect is the non-cylindrical profile of the jet as it emerges. To minimize surface tension, the jet tries to become a cylinder, but this motion overshoots and results in an oscillation in the profile shape."
What intrigued me here was the choice of phrasing: "To minimize surface tension, the jet tries to become a cylinder…". This language could be considered to reflect teleology, and even anthropomorphism.
Teleology?
Teleological explanations are those that explain something in terms of some kind of endpoint. Something happens in order to bring about some specific state of affairs. The sun shines to allow us to find our way. Plants produce oxygen so we can breathe. That is, there is seen to be purpose in nature, something that is characteristic of mythical and supernatural thinking. In science, teleological explanations are strictly considered a kind of pseudo-explanation – something that has the form of an explanation, but does not really explain anything. Sometimes we find apparently teleological explanations in science because they are being used as a kind of shorthand. For example, if we know that science suggests entropy always increases in processes, we might interpret a scientist's comment that something happens 'in order to increase entropy' to be a loose (or lazy) way of saying that some suggested mechanism or action is considered likely because it is consistent with the assumption that entropy will increase.
Here it is suggested that the odd shape is formed in order "to" minimise surface tension. Scientists have observed that many phenomena (such as rain forming roundish drops) can be explained in terms that surface tension tends to be minimised (cf. entropy tends to increase, objects tend to roll down hills, people tend to get older). But the language here might suggest minimising surface tension is an end that nature seeks – that would be a teleological explanation.
Although perhaps this is not simple teleology, as it is not that the water forms into the shape it does to minimise surface tension, but something more nuanced is going on – the jet of water is actively trying, but not quite managing, to minimise surface tension.
anthropo… (to do with humans, as in anthropology) …morphism (to do with form, as in morphology, amorphous)
…and anthropomorphism?
Anthropomorphic language refers to non-human entities as if they have human experiences, perceptions, and motivations. Both non-living things and non-human organisms may be subjects of anthropomorphism. Anthropomorphism may be used deliberately as a kind of metaphorical language that will help the audience appreciate what is being described because of its similarly to some familiar human experience. In science teaching, and in public communication of science, anthropomorphic language may often be used in this way, giving technical accounts the flavour of a persuasive narrative that people will readily engage with. Anthropomorphism may therefore be useful in 'making the unfamiliar familiar', but sometimes the metaphorical nature of the language may not be recognised, and the listener/reader may think that the anthropomorphic description is meant to be taken at face value. This 'strong anthropomorphism' may be a source of alternative conceptions ('misconceptions') of science.
So, in our present case, we are told that "the "the jet tries to become a cylinder". This is anthropomorphic, as to try to do something means having a goal in mind and deliberately behaving in a way that it is believed, expected, or – at least – hoped, will lead to that goal. Human beings can try to achieve things. We can perceive our environment, have goals, conceptualise possibilities and means to reach them, and put in practice an intention.
Whether, and, if so, which, animals can try to do things rather than simply following evolved instincts is a debated issue.
Does a dog try to please its human companion by bringing the newspaper?
Does the dolphin try to earn a fish by jumping through a hoop? Perhaps.
Does the salmon try to get to a suitable spawning site ('ground', sic) by swimming upstream?
Does the spider try to make a symmetrical web?
Does the bee try to collect nectar by visiting flowers. Probably not.
Does she try to fertiliser those flowers with pollen to ensure there will be flowers for her to visit in future seasons? Almost certainly not!
Jets of water?
Do jets of water think that being cylindrical is desirable (perhaps because they recognise minimal surface tension as an inherent good?) , and so make efforts to bring this about? Clearly not. So, they do not try to do this. They do not try to do anything. They are not the kind of entities that can try.
So, this language is metaphorical. The reader is meant to read that "the jet tries to become a cylinder" to mean something other than "the jet tries to become a cylinder". Now, often figures of speech are used in science communication because the ideas being communicated are abstract and complex, and metaphorical language that describes the science in more familiar terms makes the text more accessible and increases engagement by the audience/readership.
A question here then, is what "the jet tries to become a cylinder" communicates that was more likely to be inaccessible to the reader. Physics World is the house magazine of the Institute of Physics, which means it is sent to all it members working across all areas of physics. So a broad readership, though largely a readership of physicists.
Tracing the stream back to the source
Another question that occurred to me was whether the reporter (Jarman) was simply reporting the original researchers' (Jordan, Ribe, Deblais and Bonn) ways of communicating their work. That report was in an academic journal, Physical Review Fluids, where formal, technical language would be expected. So, I looked up the paper, to see how the work was described there.
Under a heading of 'phenomenology', Jordan and colleagues explain
"Chain oscillations are most readily observed when the viscosities of the jet and the ambient fluid are low and the interface has a high surface tension. Water jets in air satisfy these criteria, and so it is no surprise that chain oscillations occur in many everyday situations. Deformation and vibration of a jet are capillary phenomena in which surface tension acts to reduce the jet's surface area. If the cross section is not circular, its highly curved portions are pulled inward and its weakly curved portions pushed outward relative to a circular section with the same area. But due to inertia the movement overshoots, with the result that the long and short axes of the section are interchanged. The shape of the section therefore evolves as it moves along the axis of the jet, producing a steady liquid chain when observed in the laboratory frame…"
Jordan, Ribe, Deblais & Bonn, 2022
"The shape of the section therefore evolves as it moves along the axis of the jet, producing a steady liquid chain when observed"
(Image by Kevin Phillips from Pixabay)
(This seemed to be a somewhat different meaning of 'phenomenology' to that sometimes used in science education or social science more generally. Phenomenology looks to explore how people directly experience and perceive the world. Jordan and colleagues include here a good deal of re-conceptualisation and interpretation of what is directly observed. 1 )
The effect Jordan and colleagues describe seems analogous to how a pendulum bob that is released and so accelerated (by gravity) towards the point directly beneath its support (where gravitational potential is minimised) acquires sufficient momentum to overshoot, and swing upwards, beginning an oscillatory motion. Something similar is seen in an ammeter where the needle often overshoots, and initially oscillates around the value of a steady current reading (unless the spring is 'critically damped'). The effect is also made use on in striking a tuning fork.
No need to try
There is no mention here of 'trying', so no clear anthropomorphism. So, this was a gloss added in the report in Physics World, perhaps because anthropomorphic narratives are especially engaging and readily accepted by audiences; perhaps because the reporter needed to rephrase so as not to borrow too much of the original text, or perhaps as part of preparing brief copy to an editorially assigned word length. Or, perhaps Sam Jarman was not even conscious of the anthropomorphism being used, as this seems such a natural way to communicate. 2
Surface tension acting up
Did the original authors avoid teleology? They do write about how "surface tension acts to reduce the jet's surface area?" This could be read as teleological – as there seems to be a purpose or goal in the 'action', even if it is not here presented as a premeditated action. Could any suggestions of such a purpose be avoided?
One response might be that, yes, a physicist might suggest the 'true' description is a mathematical formula (and there are plenty of formulae in Jordan et al's paper) and that a verbal description is necessarily the translation of an objective description into an inherently figurative medium (natural language).
And, of course, this is not some special case. We might read that gravity acts to pull something to the ground or air resistance acts to slow a projectile down and so forth. 'To' may just imply a cause of an outcome, not a purpose.
I think a rewording along the lines "the action of the surface tension reduces the jet's surface area"conveys the same meaning, but is more of a neutral description of a process, avoiding any suggestion that there is a purpose involved.
Reading and interpreting
But does this matter? In teaching young people such as school children, there is evidence that some figurative language that is anthropomorphic or teleological may be understood in those terms, and student thinking may later reflect this. Part of science education is offering learners an insight into how science does seek to (oh, science personified: sorry, scientists seek to) describe in neutral terms and not to rely on nature having inherent goals, or comprising of the actions of sentient and deliberate agents.
The readership of Physics World is however a professional audience of members of the community of inducted physicists who are well aware that, actually, surface tension does not try to do anything; and that minimising surface tension is a common observed pattern, not something set out as a target for physical systems to aim for. These physicists are unlikely to be led astray by the engaging prose of Sam Jarman and will fully appreciate the intended meaning.
That said, there is an intimate bidirectional relationship between our thinking and our speech – our speech reflects our thought pattens, but our language also channels our thinking. So, it seems good training for a scientist to always read accounts of science with a critical filter primed to notice figurative language and to check that the communication can be understood in a non-metaphorical way. That includes checking that our understanding of what we have read is in keeping with scientific commitments to exclude explanations that are framed in terms of nature's end goals, or the deliberate agency of non-sentient 'actors'.
Jarman, S. (2022). Flowing liquid 'chains' are best described by Niels Bohr, not Lord Rayleigh. Physics World, 35(12).
Jordan, D. T. A., Ribe, N. M., Deblais, A., & Bonn, D. (2022). Chain oscillations in liquid jets. Physical Review Fluids, 7(10), 104001. doi:10.1103/PhysRevFluids.7.104001
Notes
1 However, none of us are able to be completely naive observers of the world. As William James long ago pointed out, the un-mediated sensory experience of a newborn is a chaos of noise and shapes and colours and so on. Even recognising another person or the presence of a table is an act of interpretation that we learn.
So, experts in a field do see things others do not. A field palaeontologist sees a fossil fragment where the rest of us see undifferentiated dirt and stones. The biochemist sees a steroid structure in a patterns of lines. The football pundit sees a 4-4-2 formation where the occasional viewers just sees people running around. The experienced poker player sees a 'tell' that others would not notice. The professional musician hears a passage in E minor, when most of us just hear a tune.
2 This kind of language reflects a way of thinking and talking often called 'the natural attitude'. Science can be seen in part as a deliberate move to look beyond the common-sense world of the natural attitude to problematise phenomena that might be readily taken as given.
We may get used to, and simply accept, that ice is cold, fire burns, the Lord/King makes decisions and owns the land (and people!), rivers flow, things fall down, the heretic must die, the sun moves across the sky, etc. – and probably most people did for much of human history – where the critical (scientific) attitude is to always ask 'why?'
"After a lecture on cosmology and the structure of the solar system, James [William James] was accosted by a little old lady.
'Your theory that the sun is the centre of the solar system, and the earth is a ball which rotates around it has a very convincing ring to it, Mr. James, but it's wrong. I've got a better theory,' said the little old lady.
'And what is that, madam?' inquired James politely.
'That we live on a crust of earth which is on the back of a giant turtle.'
Not wishing to demolish this absurd little theory by bringing to bear the masses of scientific evidence he had at his command, James decided to gently dissuade his opponent by making her see some of the inadequacies of her position.
'If your theory is correct, madam,' he asked, 'what does this turtle stand on?'
'You're a very clever man, Mr. James, and that's a very good question,' replied the little old lady, 'but I have an answer to it. And it's this: The first turtle stands on the back of a second, far larger, turtle, who stands directly under him.'
'But what does this second turtle stand on?' persisted James patiently.
To this, the little old lady crowed triumphantly,
'It's no use, Mr. James – it's turtles all the way down.'
Ross, 1967, iv
"The Hindoos [sic] held the earth to be hemispherical, and to be supported like a boat turned upside down upon the heads of four elephants, which stood on the back of an immense tortoise. It is usually said that the tortoise rested on nothing, but the Hindoos maintained that it floated on the surface of the universal ocean. The learned Hindoos, however, say that these animals were merely symbolical, the four elephants meaning the four directions of the compass, and the tortoise meaning eternity." (The Popular Science Monthly, March, 1877; image via Wikipedia)
It's metaphors all the way down
A well-known paper in the journal 'Cognitive Science' is entitled 'The metaphorical structure of the human conceptual system' (Lakoff & Johnson, 1980). What the authors meant by this was that metaphor, or perhaps better analogy, was at the basis of much of our thinking, and so our language.
This links to the so-called 'constructivist' perspective on development and learning, and is of great significance in both the historical development of science and in science teaching and learning. Consider some of the concepts met in a science course (electron, evolution, magnetic flux, hysteresis, oxidation state, isomerism…the list is enormous) in comparison to the kind of teaching about the world that parents engage in with young children:
That is a dog
That is a tree
That is round
This is hot
This is aunty
etc.
Pointing out the names of objects is not a perfect technique – just as scientific theories are always underdetermined by the available data (it is always possible to devise another scheme that fits the data, even if such a scheme may have to be forced and convoluted), so the 'this' that is being pointed out as a treecould refer to the corpse of trees, or the nearest branch, or a leaf, or this particular species of plant, or even be the proper name of this tree, etc. 1
Pointing requires the other person to successfully identify what is being pointed at (Images by Joe {background} and OpenClipart-Vectors {figures} from Pixabay)
But, still, the 'this' in such a case is usually more salient than the 'this' when we teach:
This is an electron
This is reduction
This is periodicity
This is electronegativity
This is a food web
This is a ᴨ-bond
This is a neurotransmitter
etc.
Most often in science teaching we are not holding up a physical object or passing it around, but offering a 'this' which is at best a model (e.g., of a generalised plant cell or a human torso) or a complex linguistic structure (a definition in terms of other abstract concepts) or an abstract representation ('this', pointing to a slope of an a graph, is acceleration; 'this', pointing to an image with an arrangement of a few letters and lines, is a transition state…).
So, how do we bridge between the likes of dogs and trees on one hand and electrons and the strong nuclear force on the other (so to speak!)? The answer is we build using analogy and we talk about those constructions using a great deal of metaphor.2 That is, we compare directly, or indirectly, with what we can experience. This refers to relationships as well as objects. We can experience being on top of, beneath, inside, outside, next to, in front of, behind, near to, a long way from (a building, say – although hopefully not beneath in that case), and we assign metaphorical relationships in a similar way to refer to abstract scenarios. (A chloroplast may be found in a cell, but is sodium found in (or on) the periodic table? Yes, metaphorically. And potassium is found beneath it!)
In a wall, the bricks on the top layer are supported by the bricks in the layer beneath – but those are in turn supported by those beneath them.
In building, we have to start at the foundations, and build up level by level. The highest levels are indirectly supported by the foundations.
(Image by OpenClipart-Vectors from Pixabay)
In science, we initially form formal concepts based on direct experience of the world (including experience mediated by our interventions, i.e., experiments), and then we build more abstract concepts from those foundational concepts, and then we build even more abstract concepts by combining the abstract ones. In the early stages we refine 'common sense' or 'life-world' categories into formal concepts so we can more 'tightly' (and operationally, through standard procedures) define what count as referents for scientific terms (Taber, 2013). So, the everyday phenomenon of burning might be reconceptualised as combustion: a class of chemical reactions with oxygen.
This is not just substituting a technical term, but also a more rigid and theoretical (abstract) conceptualisation. So, in the 'life-world' we might admit the effects of too much sunshine or contact with a strong acid within the class of 'burning' by analogy with the effect of fire (it hurts and damages the skin); but the scientific categorisation is less concerned with direct perception, and more with explanation and mechanism. So, iron burning in chlorine (in the absence of any oxygen) is considered combustion, but an acid 'burn' is not.
This is what science has done over centuries, and is also what happens in science education. So, one important tool for the teacher is concept analysis, where we check which prerequisite concepts need to be part of a student's prior learning before we introduce some new concept that is built upon then (e.g., do not try to teach mass spectroscopy before teaching about atomic structure, and do not teach about atomic structure before introducing the notion of elements; do not try to teach about the photoelectric effect to someone who does not know a little about the structure of metals and the nature of electromagnetic radiation.)
This building up of abstract concepts, one on another, is reflected in the density of metaphor we find in our language. (That is a metaphorical 'building', metaphorically placed one upon another, with a metaphorical 'density' which is metaphorically 'inside' the language and which metaphorically 'reflects' the (metaphorical) building process! You can 'see' (a metaphor for understand) just how extensive (oops, another metaphorical reference to physical space) this is. Hopefully, the (metaphorical) 'point' is (metaphorically) 'made', and so I am going to stop now, before this gets silly. 3
A case study of using language in science communication: the death of stars
Rather, I am going to discuss some examples of the language used in a single science programme, a BBC radio programme/podcast in the long-running series 'In Our Time' that took as its theme 'The Death of Stars'. The programme was hosted by Melvyn Bragg, and The Lord Bragg's guests were Professors Carolin Crawford (University of Cambridge), the Astronomer Royal Martin Rees (University of Cambridge) and Mark Sullivan (University of Southampton). This was an really good listen (recommended to anyone with an interest in astronomy), so I have certainly not picked it out to be critical, but rather to analyse the nature of some of the language used from the perspective of how that language communicates technical ideas.
An episode of 'In Our Time' on 'The Death of Stars' "The image above is of the supernova remnant Cassiopeia A, approximately 10,000 light years away, from a once massive star that died in a supernova explosion that was first seen from Earth in 1690"
A science teacher may be familiar with stars being born, living, and dying – but how might a young learner, new to astronomical ideas, make sense of what was meant?
Now there is already a point of interest in the episode title. Are stars really the kind of entities that can die? Does this mean they are living beings prior to death?
There are a good many references in the talk of these three astronomers in the episode that suggests that, in astronomy at least, stars do indeed live and die. That is, this does not seem to be consciously used as a metaphor – even if the terminology may have initially been introduced that way a long time ago. The programme offered so much material on this theme, that I have separated it out for a post of its own:
"So, in the language of astronomy, stars are born, start young, live; sometimes living alone but sometimes not, sometimes have complicated lives; have lifetimes, reach the end of their lives, and die, so, becoming dead, eventually long dead; and indeed there are generations of stars with life-cycles."
In this post I am going to consider some of the other language used.
Making the unfamiliar familiar
Language is used in science communication to the public, as it is in teaching, to introduce abstract technical ideas in ways that a listener new to the subject can make reasonable sense of. The constructivist perspective on learning tells us that meaning is not automatically communicated from speaker (or author or teacher) to listener (or reader or student). Rather, a text (spoken or written, or even in some other form – a diagram, a graph, a dance!) has to be interpreted, and this relies on the interpretive resources available to the learner. 4 The learner has to relate the communication to something familiar, and the speaker can help by using ways to make the new idea seem like something already familiar.
This is why it it is so common in communicating science to simplify, to use analogies and similes, to gesture, to use anthropomorphism and other narrative devices. There was a good deal of this in the programme, and I expect I have missed some examples. I have divided my examples into
simplifications: where some details are omitted so not to overburden the listener;
anthropomorphism: where narratives are offered such that non human entities are treated as if sentient actors, with goals, that behave deliberately;
analogies where an explicit comparison is made to map a familiar concept onto the target concept being introduced; 5
similes and metaphors: that present the technical material as being similar to something familiar and everyday.
Simplification
Simplification means ignoring some of the details, and offering a gloss on things. The details may be important, but in order to get across some key idea it is introduced as a simplification. Progress in understanding would involve subsequently filling in some details to develop a more nuanced understanding later.
In teaching there are dangers in simplification, as if the simplified idea is readily latched onto (e.g., there are two types of chemical bonds: ionic and covalent) it may be difficult later to shift learners on in their thinking. This may mean that there is a subtle balance to be judged between
giving learners enough time to become comfortable with the novel idea as introduced in a simplified form,
and
seeking to develop it out into a more sophisticated account before it become dogma.
In a one-shot input, such as a public lecture or appearance in the media, the best a scientist may be able to do is to present an account which is simple enough to understand, but which offers a sense of the science.
Simplification: all elements/atoms are formed in stars
When introducing the 'In Our Time' episode, Lord Bragg suggested that
"…every element in our bodies, every planet, was made in one of those stars, either as they burned, or as they exploded".
Clearly Melvyn cannot be an expert on the very wide range of topics featured on 'In our time' but relies on briefing notes provided by his guests. Later, in the programme he asks Professor Rees (what would clearly be considered a leading question in a research context!) "Is the sun recycled from previous dead stars?"
"Yes it is because we believe that all pristine material in the universe was mainly just hydrogen and helium, and all the atoms we are made of were not there soon after the big bang. They were all made in stars which lived and died before our solar system formed. And this leads to the problem of trying to understand more massive stars which have more complicated lives and give rise to supernovae…
The cloud from which our solar system formed was already contaminated by the debris, from earlier generations of massive stars which had lived and died more than say five billion years ago so we're literally the ashes of those long dead stars or if you are less romantic we're the nuclear waste from the fuel that kept those old stars shining."
Prof. Martin Rees
There is a potential for confusion here.
"…all the atoms we are made of were not there soon after the big bang. They were all made in stars which lived and died before our solar system formed…"
seems to be meant to convey something like
not all the atoms we are made of were there soon after the big bang. [Some were, but the rest/others] were all made in stars which lived and died before our solar system formed…
A different interpretation (i.e., that all atoms/elements are formed in stars) might well be taken, given Lord Bragg's introductory comments.
Professor Rees referred to how "…the idea that the elements, the atoms we are made of, were all synthesised in stars…" first entered scientific discourse in 1946, due to Fred Hoyle, and to
"this remarkable discovery that we are literally made of the ashes of long dead stars"
Prof. Martin Rees
Before the first star formation, the only elements present in the universe were hydrogen and helium (and some lithium) and the others have been produced in subsequent high energy nuclear processes. Nuclear fusion releases energy when heavier nuclei are formed from fusing together lighter ones, up to iron (element 56).
Forming even heavier elements requires an input of energy from another source. It was once considered that exploding stars, supernovae, gave rise to the conditions for this, but recently other mechanisms have been considered: and Prof. Sullivan described one of these:"we think these combining neutron stars are the main sites where heavy elements like strontium or plutonium, perhaps even gold or silver, these kinds of elements are made in the universe in these neutron stars combining with each other".
A human body includes many different elements, though most of these in relatively small amounts. Well represented are oxygen, carbon, calcium, and nitrogen. These elements exist because of the processes that occur in stars. However, hydrogen is also found in 'organic' substances such as the carbohydrates, proteins, and fats found in the human body. Typically the molecules of these substances contain more hydrogen atoms than atoms of carbon or any other element.
substance
formula
glucose (sugar)
C6H12O6
leucine (amino aid)
C6H13NO2
leukotriene B4 (inflammatory mediator)
C20H32O4
thymine (nucleobase)
C5H6N2O2
adreneline (hormone)
C9H13NO3
insulin (hormone)
C257H383N65O77S6
cholesterol (lipid)
C27H46O
cobalamin (vitamin B12)
C63H88CoN14O14P
formulae of some compounds found in human bodies
The body is also said to be about 60% water, and water has a triatomic molecule: two hydrogen atoms to one of oxygen (H2O). That is, surely MOST of "the atoms we are made of" are hydrogen, which were present in the universe before any stars were 'born'.
So, it seems here we have a simplification ("every element in our bodies…was made in one of those stars, either as they burned, or as they exploded"; "atoms we are made of … were all made in stars") which is contradicted later in the programme. (In teaching, it is likely the teacher would feel the need to draw the learner's attention to how the more detailed information was actually developing an earlier simplification, and not leave a learner to work this out for themselves.)
Simplification: mass is changed into energy
Explaining nuclear fusion, Prof. Crawford suggested that
"Nuclear fusion is when you combine nuclei of elements to form heavier elements, and when you do this there is a loss of mass, which is converted to energy which provides the thermal pressure and that is what counteracts the gravity and stalls the gravitational collapse."
Prof. Carolin Crawford
This seems to reflect a common alternative conception ('misconception') that, in nuclear processes, mass is converted to energy. This is often linked to Albert Einstein's famous equation E = mc2.
Actually, as discussed before here, this is contrary to the scientific account. The equation presents an equivalence between mass and energy, but does not suggest they can be inter-converted. In nuclear fusion, the masses of the new nuclei are very slightly less than the masses of the nuclei which react to form them (the difference is known as the mass defect), but this is because this omits some details of the full description of the process. If the complete process is considered then there is no loss of mass, just a reconfiguration of where the mass can be located.
Although the 4He formed has slightly less mass than four 1H; the positrons, neutrinos and gamma rays produced all have associated (energy and) mass, so that overall there is conservation of mass.
This is a bit like cooking some rice, and finding that when the rice is cooked the contents of the saucepan had slightly less weight than when we started – as some of the water we began with has evaporated and is no longer registering on our balance. In a similar way, if we consider everything that is produced in the nuclear process, then the mass overall is conserved.
As E = mc2 can be understood to tell us that mass follows the energy (or vice versa) we should expect mass changes (albeit very, very small ones) whenever work is done: when we climb the stairs, or make a cup of tea, or run down a mobile 'phone 'battery' (usually a cell?) – but mass is always conserved when we consider everything involved in any process (such as how the 'phone very, very slightly warms -and so very marginally increases the mass of – the environment).
Despite the scientific principles of conservation of energy and conservation of mass always applying when we make sure we consider everything involved in a process, I have mentioned on this site another example of an astrophysicist suggesting mass can be converted into energy: "an electron and the positron, and you put them together, they would annihilate…they would annihilate into energy" (on a different episode of 'In Our Time': come on Melvyn…we always conserve mass).
Perhaps this is an alternative conception shared by some professional scientists, but I wonder if it sometimes seems preferably to tell the "mass into energy" narrative because it is simpler than having to explain the full details of a process – which is inevitably a more complex story and so will be more difficult for a novice to take in. After all, the "mass into energy" story is likely to seem to fit with a listener's interpretive resources, as E=mc2is such a famous equation that it can be assumed that it will be familiar to most listeners, even if only a minority will have a deep appreciation of how the equivalence works.
Anthropomorphic narratives
In science learning, anthropomorphism is (to borrow a much used metaphor) a double edged sword that can cut both ways. Teachers often find that using narratives that present inanimate entities which are foci of science lessons as if they are sentient beings with social lives and motivations engages learners and triggers mental images that a student can readily remember. So, students may recall learning about what happens at a junction in a circuit in terms of a story about an electron that had to make a decision about which way to go – perhaps she took one branch while her friend tried another? They recall that covalent bonds are the 'sharing' of electrons between atoms, and indeed that atoms want, perhaps even need, to fill their electron shells, and if they manage this they will be happy.
The danger here is that for many students such narratives are not simply useful ways to get them thinking about the science concepts (weak anthropomorphism) but seem quite sufficient as the basis of explanations (strong anthropomorphism) – and so it may become difficult to shift them towards more canonical accounts. They will then write in tests that chemical reactions occur because the atoms want full shells, or that only one electron can be removed from a sodium atom because it then has a full shell. (That is, a force applied to an electron in an electric field is seen as irrelevant compared with the atom's desires. These are genuine examples reflecting what students have said.)
However, there is no doubt that framing scientific accounts within narratives which have elements of human experience as social agent does seem to help make these ideas engaging and accessible. Some such anthropomorphism is explicit, such as when gas molecules (are said to) like to move further apart, and some is more subtle by applying terms which would normally be used in relation to human experiences (not being bothered; chomping; escaping…).
What gravity did next
Consider this statement:
"All stars have the problem of supporting themselves against gravitational collapse, whether that is a star like our sun which is burning hydrogen into helium, and thus providing lots of thermal pressure to stop collapse, or whether it is a white dwarf star, but it does not have any hydrogen to burn, because it is an old dead star, fading away, so it has another method to stop itself collapsing and that is called degeneracy pressure. So, although a white dwarf is very dense, gravity is still trying to pull that white dwarf to be even denser and even denser."
Prof. Mark Sullivan
There is an explicit anthropomorphism here: from the scientific perspective gravity is nottrying to pull the white dwarf to be even denser. Gravity does not try to do anything. Gravity is not a conscious agent with goals that it 'tries' to achieve.
However, there is also a more subtle narrative thread at work – that a star has the problem of supporting itself, and it seems that when its first approach to solving this problem fails, it has a fallback method "to stop itself collapsing". But the star is just a complex system where various forces act and so processes occur. A star is not the kind of entity that can have a problem or enact strategies to achieve goals. Yet, this kind of language seems to naturally communicate abstract ideas though embedding them within an accessible narrative.
Star as moral agents
In the same way, a star is not the type of entity which can carry out immoral acts, but
"A star like our sun will never grow in mass, because it lives by itself in space. But most stars in the universe don't live by themselves, they live in what are called binary systems where you have two stars orbiting each other, rather than just the single star that we have as the sun. They are probably born with different masses, and so they evolve at different speeds and one will become a white dwarf. Now the physics is a bit complicated, but what can happen, is that that white dwarf can steal material from its companion star."
Prof. Mark Sullivan
The meaning here seems very clear, but again there are elements of using an anthropomorphic narrative. For one star to steal material from another star, that material would have to first belong to that other star, and its binary 'partner' would have to deliberately misappropriate that material knowing it belongs to its 'neighbour' (indeed, "companion").
Such a narrative breaks down on analysis. If we were to accept that the matter initially belongs to the first star (leaving aside for the moment what kind of entities can be considered to own property) then given that the material in a star got to be there through mutual gravitational attraction, the only obvious basis for ownership is that that matter has become gravitationally bound as part of that star.
If we have no other justification than that (as in the common aphorism, possession is nine points of the law), then when the material is transferred to another star because its gravitational field gives rise to a net force causing the matter to become gravitationally bound to a different star, then we should simply consider ownership to have changed. There is no theft in a context where ownership simply depends on pulling with the greater force. Despite this, we readily accept an analogy from our more familiar human social context and understand that (in a metaphorical sense) one star has stolen from another!
Actually, theft can only be carried out by moral agents – those who have capacity to intend to deprive others of their property
"A person [sic] is guilty of theft if he dishonestly appropriates property belonging to another with the intention of permanently depriving the other of it; and "thief" and "steal" shall be construed accordingly"
U.K. Theft Act 1968
Generally, these days (though this was not always so), even non-human animals are seldom considered capable of being responsible for such crimes. Admittedly, the news agency Reuters reported that as recently as 2008 "A Macedonian court convicted a bear of theft and damage for stealing honey from a beekeeper", but this seems to have been less a judgement on the ability of the bear (convicted it its absence) to engage in ethical deliberation, and more a pragmatic move that allowed the bee-keeper to be awarded criminal damages for his losses.
But, according to astronomers, stars are not only involved in the petty larceny of illicitly acquiring gas, but observations of exoplanets suggests some stars may even commit more daring, large-scale, heists,
"fairly small rocky planets two or three times the mass of the earth, in quite tight orbits around their star and you can speculate that they were once giant planets like Jupiter that have had the outer gassy layers blasted off and you are left with the rocky core, or maybe those planets were stolen from another star that got too close"
Prof. Carolin Crawford
A ménage à trois?
And there were other suggestions of anthropomorphism. It is not only stars that "don't live by themselves" in this universe,
"Nickel-56 [56Ni] is what's called an iron peak element, so it lives with iron and cobalt on the periodic table…"
Prof. Mark Sullivan
And, it is not only gravity which seems to have preferences:
"And like Mark has described with electrons not wanting to be squeezed, you have neutron degeneracy pressure. Neutrons don't like to be compressed, at some point they resist it."
Prof. Carolin Crawford
Neither electrons nor neutrons actually have any preferences: but this is an anthropomorphic metaphor that efficiently communicates a sense of the natural phenomena. 'Resist' originally had an active sense as in taking a stand, but today would not necessarily be understood that way. Wanting and liking (or not wanting and not liking), however, strictly only refer to entities that can have desires and preferences.
Navigating photons
Professor Rees explained why some imploding stars are not seen as very bright stars that fade over years, but rather observed through extremely intense bursts of high energy radiation that fade quickly,
"The energy in the form of ordinary photons, ordinary light, that's arisen in the centre of a supernova, diffuses out and takes weeks to escape, okay, but if the star is spinning, then it will be an oblate spheroid, it will have a minor axis along the spin axis, and so the easy way out is for the radiation not to diffuse through but to find the shortest escape route, which is along the spin axis, and I mention this because gamma ray bursts are … when a supernova occurs but because the original star was sort of flattened there is an easy escape route and all the energy escapes in jets along the spin axis and so instead of it diffusing out over a period of weeks, as it does in a supernova, it comes out in a few seconds."
Prof. Martin Rees
Again, the language used is suggestive. Radiation is not just emitted by the star, but 'escapes' (surely a metaphor?). The phrasing "an easy way out" implies something not being difficult. Inanimate entities like photons do not actually (literally) find anything difficult or easy. Moreover, the radiation might "find the shortest escape route": language that does not reflect a playing out of physical forces but an active search – only a being able to seek can find. Yet, again, the language supports an engaging narrative, 'softening' the rather technical story by subtly reflecting a human quest.
Professor Rees also referred to how,
"when those big stars face a crisis they blow off their outer layers"
Prof. Martin Rees
again using phrasing which seems to present the stars as deliberate actors – they actively "blow off" material when they "face a crisis". A crisis is (or at least was originally) a point where a decision needs to be made. A star does not reach the critical point where it reluctantly decides it needs to shed some material – but rather is subject to changing net forces as the rate of heat generation from nuclear processes starts to decrease.
A sense of anthropomorphic narrative also attaches to Professor Crawford's explanation of how more massive stars process material faster,
"…more massive stars … actually have shorter lifetimes …they have to chomp through their fuel supply so furiously that they exhaust it more rapidly
Prof. Carolin Crawford
'Chomping', a term for vigorous eating (biting, chewing, munching), is here a metaphor, as a star does not eat – as pointed out in the companion piece, nutrition is a characteristics feature of living things, but does not map across to stars even if they are described as being born, living, dying and so forth. To be furious is a human emotional response: stars may process their remaining hydrogen quickly, but there is no fury involved. Again, though, the narrative, perhaps inviting associated mental imagery, communicates a sense of the science.
Laid-back gas
Another example of anthropomorphism was
"…if you have a gas cloud that's been sitting out in space for billions of years and has not bothered to contract because it's been too hot or it's too sparse…"
Prof. Carolin Crawford
This is an interesting example, as Prof. Crawford explicitly explains here that the gas cloud has not contracted because of the low density of material (so weak gravitational forces acting on the particles) and/or the high temperature (so the gas comprises of energetic, so fast moving, particles), so the suggestion that the material cannot be bothered (implication: that the 'cloud' operates as a single entity, and is sentient if perhaps a little lazy) does not stand in place of a scientific explanation, but rather simply seems to be intended to 'soften' (so to speak) the technical nature of the language used.
Analogy
An analogy goes beyond a simile or metaphor because there is some kind of structural mapping to make it explicit in what way or ways the analogue is considered to be like the target concept. 5 (Such as when explaining mass defect in relation to the material lost from the saucepan when cooking rice!)
A potential teaching analogy to avoid alternative conceptions about mass defect in nuclear processes
So, Prof. Rees suggests that scientists can test their theories about star 'life cycles' by observation, even though an individual star only moves through the process over billions of years, and uses an analogy to a more familiar everyday context:
"We can test our theories, not only because we understand the physics, but because we can look at lots of stars. It is rather like if you had never seen a tree before, and you wandered around in a forest for a day, you can infer the life cycles of trees, you'd see saplings and big trees, etcetera. And so even though our lifetime is minuscule compared to the lifetime of a stable star, we can infer the population and life cycles of stars observationally and the theory does corroborate that fairly well."
Prof. Martin Rees
This would seem to make the basis of a good teaching analogy that could be discussed with students and would likely link well with their own experiences.
The other explicit analogy introduced by Prof. Rees is one well-known to physics teachers (sometimes in an ice-skater variant),
"If a contracting cloud has even a tiny little bit of spin, if it is rotating a bit, then as it contracts, then just like the ballerina who pulls in her arms and spins faster, then the contracting cloud will start to spin faster…"
Prof. Martin Rees
Stellar similes
I take the difference between a simile and a metaphor as the presence of an explicit marker (such as '…as…',…like…') to tell the listener/reader that a comparison is being made – so 'the genome is the blueprint for the body' would be a metaphor, where 'the genome is like a blueprint for the body' would be a simile.
As if a black hole cuts itself off
So, when Professor Rees describes how a massive black hole forms, he uses simile (i.e., "…as if were…"),
"So, if a neutron star gets above that mass, then it will compress even further, and will become a black hole – it will go on contracting until it, as it were, cuts itself off from the rest of the universe, leaving a gravitational imprint frozen in the space that's left. It becomes a black hole that things can fall into but not come out."
Prof. Martin Rees
There is an element of anthropomorphic narrative (see above) again here, if we consider the choice of active, rather than passive, phrasing
…as it were, cuts itself off from the rest of the universe, compared with
…as it were, becomes cut off from the rest of the universe
This is presented as something the neutron star itself does ("it will compress…become a black hole – it will go on contracting until it, as it were, cuts itself off…") rather than a process occurring in/to the matter of which it is comprised.
As if galaxies drop over the horizon
Prof. Rees uses another simile, when talking of how the expansion of space means that in time most galaxies will disappear from view,
"All the more distant universe which astronomers like Mark [Sullivan] study, galaxies far away, they will all have expanded their distance from us and in effect disappeared over a sort of horizon and so we just wouldn't see them at all. They'd be too faint, rather like …an inside-out black hole as it were, but in this case they moved so far away that we can't see them any more …"
Prof. Martin Rees
The term horizon, originally referring to the extent of what is in sight as we look across the curved Earth, has become widely used in astronomical contexts where objects cease to be in sight (i.e., the event horizon of a black hole beyond which any light being emitted by an object will not be able to leave {'escape!'} the black hole because of the intense gravitation field), but here Prof. Rees clearly marks out for listeners ("…in effect…a sort of…") that he is making a comparison with the familiar notion of a horizon that we experience here on Earth.
There is another simile here, the reference to the expansion of space leading to an effect "rather like…an inside-out black hole as it were" – but perhaps that comparison would be less useful to a listener new to the topic as it uses a scientific idea rather than an everyday phenomenon as the analogue.
Through a glass onion darkly?
Another simile used by Professor Rees was a references to a "sort of onion skin structure". Now 'onion skin' sometimes refers to the hard, dry, outer material (the 'tunic') usually discarded when preparing the onion for a dish. To a science teacher, however, this is more likely to mean the thin layer of epithelial tissue that can be peeled from the scales inside the bulb. These scales, which are potentially the bases of leaves that can grow if the bulb is planted, are layered in the bulb.
The skin is useful in science lessons as it is a single layer of cells, that is suitable for students to dissect from the onion, and mount for microscopic examination – allowing them to observe the individual cells. There is something at least superficially analogous to this in stars. Observations of the Sun show that convection processes gives rise to structures referred to as convection 'cells'.
Convection 'cells' at the Sun's surface (Source: NASA)Onion skin magnified showing individual epithelial cells (Source: Wikimedia commons)
Yet, when Professor Rees' simile is heard in context, it seems that this is not the focus of the comparison:
"…all the nuclear processes which would occur at different stages in the heavy stars…which have this sort of onion skin structure with the hotter inner layers"
Prof. Martin Rees
Very large stars that have processed much of their hydrogen into helium can be considered to have a layered structure where under different conditions a whole sequence of processes are occurring leading to the formation of successively heavier and heavier elements, and ultimately to a build-up of iron near the centre.
The onion model of the structure of a large star (original image by Taken from Pixabay)
When I heard the reference to the onion, this immediately suggested the layered nature of the onion bulb being like the structure of a star that was carrying out the sequence of processes where the products of one fusion reaction become the raw material for the next. Presumably, my familiarity with the layered model of a star led me to automatically make an association with onions which disregarded the reference to the skin. That is, I had existing 'interpretive resources' to understand why the onion reference was relevant, even though the explicit mention of the skin might make the comparison obscure to someone new to the science.
Metaphors – all the way back up?
Some metaphors can easily be spotted (if someone suggests mitochondria are the power stations of the cell, or a lion is King of the jungle), but if our conceptual systems, and our language, are built by layers of metaphor upon metaphor then actually most metaphors are dead metaphors.
That is, an original metaphor is a creative attempt to make a comparison with something familiar, but once the metaphor is widely taken up, and in time becomes common usage and so a part of standard language, it ceases to act as a metaphor and becomes a literal meaning.
This presumably is what has happened with the adoption of the idea that stars are born, live out their lives, and then die: originally it was a poetic use of language, but now among astronomers it reflects an expanded standard use of terms that were once more restricted (born, live, lifetime, die etc.).
"…Stars dived in blinding skies / Stars die / Blinding skies…" Stars die, but only due to artistic license (Artwork from 'Star's die' by Porcupine Tree, photographer: Chris Kissadjekian)
If you see a standard candle…
When Professor Sullivan refers to a "standard candle", this is now a widely used astronomical notion (in relation to how we estimate distances to distant stars and galaxies that are much too far away to triangulate from parallax as the earth changes its position in the solar system) – but at one time this was used as a figure of speech.
Some figures of speech are created in the moment, but never widely copied and adopted. The astronomical community adopted the 'standard candle' such that it is now an accepted term, even though most young people meeting astronomical ideas for the first time probably have very little direct experience of candles. What might once have seemed a blatantly obvious allusion may now need explaining to the novice.
When Sir Arthur Eddington (famous for collecting observations during an eclipse consistent with predictions from relativity theory about the gravitational 'bending' of starlight) gave a public lecture in 1932, he seems to have assumed that his audience would understand the analogy between an astronomer's 'standard candles' (Cepheid variables) and standard candles they might themselves use!
"If you see a standard candle anywhere and note how bright it appears to you, you can calculate how far off it is; in the same way an astronomer observes his [or her] 'standard candle' in the midst of a nebula, notes its apparent brightness or magnitude, and deduces the distance of the nebula"
Eddington, 1933/1987, pp.7-8
This ongoing development in language means that it may not always be entirely clear which terms are still engaged with as if metaphors and which have now become understood as literal. That is, in considering whether some phrase is a metaphor we can ask two questions:
did the author/speaker intend this as a comparison, or do they consider the term has direct literal meaning?
does the reader/listener understand the term to have a literal meaning, or is it experienced as some novel kind of comparison with another context which has to be related back to the focus?
In the latter case we might also think it is important to distinguish between cases where the audience member can decode the intention of the comparison 'automatically' as part of normal language processing – and cases where they would have to consciously deliberate on the meaning. (In the latter case, the interpretation is likely to disrupt the flow of reading, and when listening could perhaps even require the listener to disengage from the communication such that subsequent speech is missed.)
(Metaphorical?) hosts
So, when Prof. Crawford suggests that
"The supernovae, particularly, are of fundamental importance for the host galaxy…"
Prof. Carolin Crawford
her use of the term 'host' is surely metaphorical (at least for a listener– this term is widely used in the literature of academic astronomy 6). A host offers hospitality for a guest. That does not seem to obviously reflect the relationship between a supernova and the galaxy it is found in and is part of. It is not a guest: rather, in Prof. Sullivan's terms we might suggest that star has 'lived its entire life' in that galaxy – it is its galactic 'home'. Despite this comparison not standing up to much formal analysis, I suspect the metaphor can be automatically processed by anyone with strong familiarity with the concept of a host. Precise alignment may not be a strong criterion for effective metaphors.
Another meaning of host refers to a sacrificial victim (as in the host in the Christian Eucharist) which seems unlikely to be the derivation here, but perhaps fits rather well with Prof. Crawford's point. A supernova too close to earth could potentially destroy the biosphere – an unlikely but not impossible event.
(Metaphorical?) bubbles
Professor Crawford described some of the changes during a supernova,
"You have got your iron core, it collapses down under gravity in less than a second, that kind of leaves the outer layers of the star a little behind, they crash down, bounce on the surface of the core, and then there's a shockwave, that propels all this stellar debris, out into space. So, this is part of the supernova explosion we have been talking about, and it carves out a bubble within the interstellar medium."
Prof. Carolin Crawford
There are a number of places here where everyday terms are applied in an unfamiliar context such as 'core', 'bouncing', 'layers' and 'debris'. But the idea of carving a bubble certainly seems metaphorical, if only because a familiar bubble would have a physical surface, where surely, here, there is no strict interface between discrete regions of gases. But, again, the term offers an accessible image to communicate the process. (And anyone looking at the NASA image above of convection cells in the Sun might well feel that these can be perceived as if bubbles.)
(Metaphorical?) pepper
Similarly, the idea of heavy elements from exploding suns being added to the original hydrogen and helium in the interstellar medium as like adding pepper also offers a strong image,
"…this is the idea of enrichment, you start off with much more primordial hydrogen and helium gas that gets steadily peppered with all these heavy elements…"
Prof. Carolin Crawford
Perhaps 'peppered' is now a dead metaphor, as it is widely used in various contexts unrelated to flavouring food.
(Metaphorical?) imprints
When Professor Rees referred to a neutron star that has become a black hole leaving a "gravitational imprint frozen in the space that's left" this makes good sense as the black hole will not be visible, but its gravitational field will have effects well beyond its event horizon. Yet, one cannot actually make an imprint in space, one needs a suitable material substrate (snow, plater, mud…) to imprint into; and nor has anything been 'frozen' in a literal sense. Indeed, the gravitational field will change as the black hole acquires more material through gravitational capture (and in the very long term loses mass though evaporates Hawking radiation – which is said to cause the black hole to 'evaporate'). So, this is a kind of double metaphor.
(Metaphorical?) blasts and blows
I report above both the idea that rocky planet close to large stars might have derived from 'giant' planets "that have had the outer gassy layers blasted off" and how "big stars…blow off their outer layers". Can stars really blow, or is this based on a metaphor. Blasts usually imply explosions, sudden events, so perhaps these are metaphorical blasts? And it is not just larger stars that engage in blowing off,
"[The sun] will blow off its outer layers and become a red giant, expanding so it will engulf the inner planets, but then the core will settle down to what's called a white dwarf, this is a dead, dense star, about a million times denser than normal stuff…."
Prof. Martin Rees
Metaphors galore!
Perhaps those last examples are not especially convincing – but this reflects a point I made earlier. Language changes over time: it is (metaphorically-speaking) fluid. If language started from giving names to things we can directly point at, then anything we cannot directly point at needs to be labelled in terms of existing words. Most of the terms we use were metaphors at some point, but became literal as the language norms changed.
But society is not a completely homogeneous language community. The requirements of professional discourse in astronomy (or any other specialised field of human activity) drive language modifications in particular regards ahead of general language use. It is not just people in Britain and the United States who are divided by a common language – we all are to some extent. What has become literal meaning for for one person (perhaps a science teacher) may well only be a metaphor to another (a student, say).
After all, when I look up what it is to blow off, I find that the most common contemporary meaning relates to a failure to meet a social obligation or arrangement – I am pretty sure (from the context) that that is not what Professor Rees was suggesting ("…when those big stars face a crisis they [let down] their outer layers".) Once we start looking at texts closely, they seem to be 'loaded' with figures of speech. A planet is not materially constrained in space, yet we understand why an orbit might be considered 'tight'.
In the proceeding quote, the core of a star seems to need no explanation although it presumably derives by analogy with the core of an apple or similar fruit, which itself seems to derive metaphorically form an original meaning of the heart. Again, what is meant by engulf is clear enough although originally it referred to the context of water and the meaning has been metaphorically (or analogously) extended.
The terms red giant and white dwarf clearly derive from metaphor. (Sure, a red giant isgigantic, but then, on any normal scale of human experience, so is a white dwarf.) These terms might mystify someone meeting them for the first time so not already aware they are used to refer to classes of star. This might suggest the value of a completely objective language for discussing science where all terms are tightly (hm, too metaphorical…closely? rigidly? well-) defined, but that would be a project reminiscent of the logical positivist programme in early twentieth century that ultimately proved non-viable. We can only define words with more words, and there are limits to the precision possible with a usable, 'living', language.
Take the "discovery that we are literally made of the ashes of long dead stars". Perhaps, but the term ashes normally refers to the remains of burnt organic material, especially wood, so perhaps we are not literally, but only metaphorically made of the ashes of long dead stars. Just as when when Professor Sullivan noted,
"the white dwarf is made of carbon, it's made of oxygen, and the temperature and the pressure in the centre of that white dwarf star can become so extreme, that carbon detonation can occur in the centre of the white dwarf, and that is a runaway thermonuclear reaction – that carbon burns in astronomer speak into more massive elements…"
Prof. Mark Sullivan
Are we stardust, ashes or just waste?
Burning is usually seen in scientific terms as another word for combustion. So, the nuclear fusion, 'burning' "in astronomer speak" of its nuclear 'fuel' in a star represents an extension of the original meaning by analogy with combustion. 9 Material that is deliberately used to maintain a fire is fuel. A furnace is an artefact deliberately built to maintain a high temperature – the nuclear furnace in a star is not an artefact but a naturally occurring system (gravity holds the material in place), but is metaphorically a furnace. A runaway is a fugitive who has absconded – so to describe a thermonuclear reaction (which is not going anywhere in spatial terms) as 'runaway' adopts what was a metaphor. (Astronomers also use the term 'runaway' to label a class of star that seem to be moving especially fast compared with the interstellar medium – a somewhat more direct borrowing of the usual meaning of 'runaway'.)
To consider us to be made from 'nuclear waste' relies on seeing the star-as-nuclear-furnace as analogous to a nuclear pile in a power station. In nuclear power stations we deliberately process fissile material to allow us to generate electrical power: and material is produced as a by-product of this process (that is, it is a direct product of the natural nuclear processes, but a by-product of our purposeful scheme to generate electricity). To consider something waste means making a value judgement.
If the purpose of a star is to shine (a teleological claim) and the fusion of hydrogen is the means to achieve that end, then the material produced in that process which is no longer suitable as 'fuel' can be considered 'waste'. If the universe does not have any purpose(s) for stars then there is no more basis for seeing this material as waste than there is for seeing stars themselves as the waste products of a process that causes diffuse matter to come together into local clumps. That is, this is an anthropocentric perspective that values stars as of more value than either the primordial matter from which they formed, or the 'dead' matter they will evolve into when they no longer shine 'for us'. Nature may not have such favourites! If it has a purpose, then stars seem to only be intermediate steps towards its ultimate end.
What does support the turtle? Surely, it's metaphors all the way down. (Source: Pintrest)
Sources cited:
Eddington, A. (1933/1987). The Expanding Universe. Cambridge: Cambridge University Press.
Lakoff, G., & Johnson, M. (1980). The metaphorical structure of the human conceptual system. Cognitive Science, 4(2), 195-208.
Ulmer, M., Grace, V., Hudson, H., & Schwartz, D. (1972). Upper Limits to the X-Ray Luminosities of Five Supernovae. The Astrophysical Journal, 173, 205.
Notes:
1 It may seem fanciful that we give a specific individual tree a proper name but should a child inherently appreciate that we commonly name individual hamsters (say, or ships, or roads), but not individual trees? 'Major Oak'is a particular named Oak tree in Sherwood Forest, so the idea is not ridiculous. (It is very large, but apparently the name derives from it being described by an author with the army rank of major. Of course, this term for a soldier leading others derives metaphorically from a Latin word meaning bigger, so…)
2 "So how do we bridge between dogs and trees on one hand and electrons and the strong nuclear force on the other (so to speak!)? The answer is we build using analogy and we talk about those constructions using a great deal of metaphor."
We understand what is meant by bridge here in relation to an actual bridge that physically links two places – such as locations on opposite sides of a river or railway line.
There is no actual building up of materials, but we understand how we can 'build' in the abstract by analogy.
These things are not actually at hand, but we make a metaphorical comparison in terms of distinguishing items held in 'opposite' hands. We understand what is meant by a great deal of something abstract by analogy with a great deal of something we can directly experience, e.g., sand, water, etcetera.
Justice personified, on the one hand weighing up the evidence and on the other imposing sanctions
(Image by Sang Hyun Cho from Pixabay)
We construct scientific concepts and models and theories by analogy with how we construct material buildings – we put down foundations then build up brick by brick so that the top of the structure is only very indirectly supported by the ground.
(Image by joffi from Pixabay)
3 A point is a hypothetical, infinitesimally small, location in space, which is not something a person could actually make. The 'point' of an argument is metaphorically like the point of a pencil or spear which is metaphorically an approximation to an actual point. Of course, we (adult members of the English language community) all know what is meant by the point of an argument – but people new to a language (such as young children) have to find this out, without someone holding up the point of an argument for them to learn to recognise.
4 In part, this means linguistic resources. Each individual person has a unique vocabulary, and even though sharing most words with others, often has somewhat unique ranges of application of those words. But it also refers to personal experiences that can be drawn upon (e.g., having cared for an ill relative, having owned a pet, having undertaken part-time work in a hospital pharmacy, having been taken to work by a parent…) and the cultural referents that are commonly discussed in discourse (cultural icons like the Mona Lisa or Beethoven's fifth symphony; familiarity with some popular television show or film; appreciating that Romeo and Juliet were tragic lovers, or that Gandhi is widely considered a moral role model, and so forth.)
"Penny, I'm a physicist. I have a working knowledge of the entire universe and everything it contains."
"Who's Radiohead?"
"I have a working knowledge of the important things in the universe."
Still from 'The Big Bang Theory' (Chuck Lorre Productions / Warner Bros. Television)
The interpretive resources are whatever mental resources are available to help make sense of communication.
5 I am using the term concept in an 'inclusive' sense (Taber, 2019), in that whenever a person can offer a discrimination about whether something is an example of some category, then they hold a concept (vague or detailed; simple or complex; canonical or alternative).
That is, if someone can (beyond straight guesswork) try to answer one of the questions "what is X? ", "is this an example of X?" or "can you suggests an example of X?", then they have a relevant concept – where X could be…
6 The earliest reference to 'host galaxies' I found in a quick search of the scientific literature was from 1972 in a paper which used the term 'host galaxy' 8 times, including,
"We estimated the distances [of observed supernovae]…by four different methods:
(1) Estimating the absolute luminosity of the host galaxy.
(2) Estimating the absolute luminosity of the supernova.
(3) Using the measured redshift of the host galaxy and assuming the Hubble constant H = 75 km (s Mpc)-1 …
(4) Identifying the host galaxy with a cluster of galaxies for which the distance from Earth had already been estimated.
Ulmer, Grace, Hudson & Schwartz, 1972, p.209
The term 'host galaxy' was not introduced or defined in the paper, suggesting that either it was already in common use as a scientific term (and so a dead metaphor within the astronomical community) in 1972 or Ulmer and colleagues assumed it was obvious enough not to need explanation.
7 It should be pointed out that 'In Our Time' is not presented as succession of mini-lectures, or as a tightly scripted programme, but as a conversation between Melvyn as his guests. Of course, there is some level of preparation by those involved, but in adopting a conversational style, avoiding the sense of prepared statements, it is inevitable that a guest's language will sometimes lack the precision of a drafted and much revised account.
8 A supernova may appear as a new star in the sky if it is so far away that the star was not previously detectable, or as a known star quick;y becoming very much brighter.
9 One should be careful in making such equivalences, as in that although we may equate burning with combustion, burning is an everyday ('life world') phenomenon, and combustion is a scientific concept: often our scientific concepts are more precisely defined than the related everyday terms. (Which is why melting has a broader meaning in everyday life {the sugar melts in the hot tea; the stranger melted away into the mist} than it does in science.) But although we might say, as suggested earlier in the text, we have been burned by exposure to the sun's ultraviolet rays, or by contact with a caustic substance, in those contexts we are unlikely to consider our skin as 'fuel' for the process.
It seems a bloated star dimmed because it sneezed, and spewed out a burp.
'Pardon me!' (Image by Angeles Balaguer from Pixabay)
I was intrigued to notice a reference in Chemistry World to a 'stellar burp'.
"…the dimming of the red giant Betelgeuse that was observed in 2019…was later attributed to a 'stellar burp' emitting gas and dust which condensed and then obscured light from the star"
Motion, 2022
The author, Alice Motion, quoted astrophysics doctoral candidate and science communicator Kirsten Banks commenting that
"In recorded history…It's the first time we've ever seen this happen, a star going through a bit of a burp"
although she went on to suggest that the Boorong people (an indigenous culture from an area of the Australian state Victoria) had long ago noticed a phenomena that became recorded in their oral traditions 1, which
"was actually the star Eta Carinae which went through a stellar burp, just like Betelgeuse did"
Clearly a star cannot burp in the way a person can, so I took this to be a metaphor, and wondered if this was a metaphor used in the original scientific report.
A clump and a veil
The original report (Montargès, et al, 2021) was from Nature, one of the most prestigious science research journals. It did not seem to have any mention of belching. This article reported that,
"From November 2019 to March 2020, Betelgeuse – the second-closest red supergiant to Earth (roughly 220 parsecs, or 724 light years, away) – experienced a historic dimming of its visible brightness…an event referred to as Betelgeuse's Great Dimming….Observations and modelling support a scenario in which a dust clump formed recently in the vicinity of the star, owing to a local temperature decrease in a cool patch that appeared on the photosphere."
Montargès, et al., 2012, p.365
So, the focus seemed to be not on any burping but a 'clump' of material partially obscuring the star. That material may well have arisen from the star. The paper in nature suggests that Betelgeuse may loose material through two mechanisms: both by a "smooth homogeneous radial outflow that consists mainly of gas", that is a steady and continuous process; but also "an episodic localised ejection of gas clumps where conditions are favourable for efficient dust formation while still close to the photosphere" – that is the occasional, irregular, 'burp' of material, that then condenses near the star. But the word used was not 'burp', but 'eject'.
A fleeting veil
Interestingly the title of the article referred to "A dusty veil shading Betelgeuse". The 'veil' (another metaphor) only seemed to occur in the title. There is an understandable temptation, even in scholarly work, to seek a title which catches attention – perhaps simplifying, alliterating (e.g., '…mediating mental models of metals…') or seeking a strong image ('…a dusty veil shading…'). In this case, the paper authors clearly thought the metaphor did not need to be explained, and that readers would understand how it linked to the paper content without any explicit commentary.
Word
Frequency in Nature article
clump(s)
25 (excluding reference list)
eject(ed, etc.)
4
veil
1 (in title only)
burp
0
blob
0
There's no burping in Nature
The European Southern Observatory released a press release (sorry, a 'science release') about the work entitled 'Mystery of Betelgeuse's dip in brightness solved', that explained
"In their new study, published today in Nature, the team revealed that the mysterious dimming was caused by a dusty veil shading the star, which in turn was the result of a drop in temperature on Betelgeuse's stellar surface.
Betelgeuse's surface regularly changes as giant bubbles of gas move, shrink and swell within the star. The team concludes that some time before the Great Dimming, the star ejected a large gas bubble that moved away from it. When a patch of the surface cooled down shortly after, that temperature decrease was enough for the gas to condense into solid dust.
'We have directly witnessed the formation of so-called stardust,' says Montargès, whose study provides evidence that dust formation can occur very quickly and close to a star's surface. 'The dust expelled from cool evolved stars, such as the ejection we've just witnessed, could go on to become the building blocks of terrestrial planets and life', adds Emily Cannon, from KU Leuven, who was also involved in the study."
So, again, references to ejection and a veil – but no burping.
Delayed burping
Despite this, the terminology of the star burping, seems to have been widely taken up in secondary sources, such as the article in Chemistry World
A New Scientist report suggested "Giant gas burp made Betelgeuse go dim" (Crane, 2021). On the website arsTECHNICA, Jennifer Ouellette wrote that "a cold spot and a stellar burp led to strange dimming of Betelgeuse".
On the newsite Gizmodo, George Dvorsky wrote a piece entitled "A dusty burp could explain mysterious dimming of supergiant star Betelgeuse". Whilst the term burp was only used in the title, Dvorsky was not shy of making other corporeal references,
"a gigantic dust cloud, which formed after hot, dense gases spewed out from the dying star. Viewed from Earth, this blanket of dust shielded the star's surface, making it appear dimmer from our perspective, according to the research, led by Andrea Dupree from the Centre for Astrophysics at Harvard & Smithsonian.
A red supergiant star, Betelgeuse is nearing the end of its life. It's poised to go supernova soon, by cosmological standards, though we can't be certain as to exactly when. So bloated is this ageing star that its diameter now measures 1.234 million kilometers, which means that if you placed Betelgeuse at the centre of our solar system, it would extend all the way to Jupiter's orbit."
The New York Times published an article (June 17, 2021) entitled "Betelgeuse Merely Burped, Astronomers Conclude", where author Dennis Overbye began his piece:
Overbye also reports the work from the Nature paper
"We have directly witnessed the formation of so-called stardust," Miguel Montargès, an astrophysicist at the Paris Observatory, said in a statement issued by the European Southern Observatory. He and Emily Cannon of Catholic University Leuven, in Belgium, were the leaders of an international team that studied Betelgeuse during the Great Dimming with the European Southern Observatory's Very Large Telescope on Cerro Paranal, in Chile.
Parts of the star, they found, were only one-tenth as bright as normal and markedly cooler than the rest of the surface, enabling the expelled blob to cool and condense into stardust. They reported their results on Wednesday in Nature."
So, instead of the clumps referred to in the Nature article as ejected, we now have an expelled blob (neither word appears in the nature article itself). Overbye also explains how this study followed up on earlier observations of the star
"Their new results would seem to bolster findings reported a year ago by Andrea Dupree of the Harvard-Smithsonian Center for Astrophysics and her colleagues, who detected an upwelling of material on Betelgeuse in the summer of 2019.
'We saw the material moving out through the chromosphere in the south in September to November 2019,', Dr. Dupree wrote in an email. She referred to the expulsion as 'a sneeze.'
'…material moving out through the chromosphere in the south…': Hubble space telescope images of Betelgeuse (Source: NASA) 2
Bodily functions and stellar processes
I remain unsure why, if the event was originally considered a sneeze, it became transformed into a burp. However the use of such descriptions is not so unusual. Metaphor is a common tool in science communication to help 'make the unfamiliar familiar' by describing something abstract or out-of-the-ordinary in more familiar terms.
Here, the body [sic] of the scientific report keeps to technical language although a metaphor (the dust cloud as a veil) is considered suitable for the title. It is only when the science communication shifts from the primary literature (intended for the science community) into more popular media aimed at a wider audience that the physical processes occurring in a star became described in terms of our bodily functions. So, in this case, it seems a bloated star dimmed because it sneezed, and spewed out a burp.
Coda
The astute reader may have also noticed that the New York Times article referred to Betelgeuse as an "ageing star" that is "nearing the end of its life": terms that imply a star is a living, and mortal, being. This might seem to be journalistic license, but the NASA website from which the sequence of Betelgeuse images above are taken also refers to the star as ageing (as well as being 'petulant' and 'injured').2 NASA employs scientifically qualified people, but its public websites are intended for a broad, general audience, perhaps explaining the anthropomorphic references.
Crane, L. (2021). Giant gas burp made Betelgeuse go dim. New Scientist, 250(3340), 22. doi:10.1016/S0262-4079(21)01094-0
Hamacher, D. W., & Frew, D. J. (2010). An aboriginal Australian record of the great eruption of Eta Carinae. Journal of Astronomical History and Heritage, 13(3), 220-234.
Montargès, M., Cannon, E., Lagadec, E., de Koter, A., Kervella, P., Sanchez-Bermudez, J., . . . Danchi, W. (2021). A dusty veil shading Betelgeuse during its Great Dimming. Nature, 594(7863), 365-368. doi:10.1038/s41586-021-03546-8
1 William Edward Stanbridge (1816-1894) was an Englishman who moved to Australia in 1841. He asked Boorong informants about their astronomy, and recorded their accounts. He presented a report to the Philosophical Institute of Victoria in 1857 and published two papers (Hamacher & Frew, 2010). The website Australian Indigenous Astronomy explains that
"The larger star of [of the binary system] Eta Car is unstable and undergoes occasional violent outbursts, where it sheds material from its outer shells, making it exceptionally bright. During the 1840s, Eta Car went through such an outburst where it shed 20 solar masses of its outer shell and became the second brightest star in the night sky, after Sirius, before fading from view a few years later. This event, commonly called a "supernova-impostor" event, has been deemed the "Great Eruption of Eta Carinae". The remnant of this explosion is evident by the Homunculus Nebulae [see figure above – nebulae are anything that appears cloud-like to astronomical observation]. This identification shows that the Boorong had noted the sudden brightness of this star and incorporated it into their oral traditions."
A paper in the Journal of Astronomical History and Heritage concludes that
"the Boorong people observed 𝜂 Carinae in the nineteenth century, which we identify using Stanbridge's description of its position in Robur Carolinum, its colour and brightness, its designation (966 Lac, implying it is associated with the Carina Nebula), and the relationship between stellar brightness and positions of characters in Boorong oral traditions. In other words, the nineteenth century outburst of 𝜂 Carinae was recognised by the Boorong and incorporated into their oral traditions"
Hamacher & Frew 2010, p.231
2 The images reproduced here are presented on a NASA website under the heading 'Hubble Sees Red Supergiant Star Betelgeuse Slowly Recovering After Blowing Its Top'. This is apparently not a metaphor as the site informs readers that"Betelgeuse quite literally blew its top in 2019". Betelgeuse is described as a "monster star", and its activity as "surprisingly petulant behaviour" and a "titanic convulsion in an ageingstar", such that "Betelgeuse is now struggling to recover from this injury."
This seems rather anthropomorphic – petulance and struggle are surely concepts that refer to sentient deliberate actors in the world, not massive hot balls of gas. However, anthropomorphic narratives are often used to make scientific ideas accessible.
The recovery (from 'injury') is described in terms of two similes,
"The star's interior convection cells, which drive the regular pulsation may be sloshing around like an imbalanced washing machine tub, Dupree suggests. … spectra imply that the outer layers may be back to normal, but the surface is still bouncing like a plate of gelatin dessert [jelly] as the photosphere rebuilds itself."
What can either wander door to door, or rush to respond; and when it arrives might touch, sniff, nip, rear up, stroke, seal, or kill?
Keith S. Taber
a science teacher would need to be more circumspect in throwing some of these metaphors out there, without then doing some work to transition from them to more technical, literal, and canonical accounts
BBC Radio 4's 'Start the week' programme is not a science programme, but tends to invite in guests (often authors of some kind) each week according to some common theme. This week there was a science theme and the episode was titled 'Building the Body, Opening the Heart', and was fascinating. It also offers something of a case study in how science gets communicated in the media.
Sian Harding is Professor of Cardiac Pharmacology at the National Heart and Lung Institute, Imperial College London, and Director of the Imperial Cardiac Regenerative Medicine Centre
As a science educator I listen to science programmes both to enhance and update my own science knowledge and understanding, but also to hear how experts present scientific ideas when communicating to a general audience. Although neither science popularisation nor the work of scientists in communicating to the public is entirely the same as formal teaching (for example,
there is no curriculum with specified target knowledge; and
the audiences
are not well-defined,
are usually much more diverse than found in classrooms, and
are free to leave at any point they lose interest or get a better offer),
they are, like teachers, seeking to inform and explain science.
Science communicators, whether professional journalists or scientists popularising their work, face similar challenges to science teachers in getting across often complex and abstract ideas; and, like them, need to make the unfamiliar familiar. Science teachers are taught about how they need to connect new material with the learners' prior knowledge and experiences if it is to make sense to the students. But successful broadcasters and popularisers also know they need to do this, using such tactics as simplification, modelling, metaphor and simile, analogy, teleology, anthropomorphism and narrative.
Perhaps one of the the biggest differences between science teaching and science communication in the media is the ultimate criterion of success. For science teachers this is (sadly) usually, primarily at least, whether students have understood the material, and will later recall it, sufficiently to demonstrate target knowledge in exams. The teacher may prefer to focus on whether students enjoy science, or develop good attitudes to science, or will consider working in science: but, even so, they are usually held to account for students' performance levels in high-stakes tests.
Science journalists and popularisers do not need to worry about that. Rather, they have to be sufficiently engaging for the audience to feel they are learning something of interest and understanding it. Of course, teachers certainly need to be engaging as well, but they cannot compromise what is taught, and how it is understood, in order to entertain.
With that in mind, I was fascinated at the range of ways the panel of guests communicated the science in this radio show. Much of the programme had a focus on cells – and these were described in a variety of ways.
Talking about cells
Dr Rutherford introduced cells as
"the basic building blocks of life on earth"; and observed that he had
"spent much of my life staring down microscopes at these funny, sort of mundane, unremarkable, gloopy balloons"; before suggesting that cells were
"actually really these incredible cities buzzing with activity".
Dr. Mukherjee noted that
"they're fantastical living machines" [where a cell is the] "smallest unit of life…and these units were built, as it were, part upon part like you would build a Lego kit"
Listeners were told how Robert Hooke named 'cells' after observing cork under the microscope because the material looked like a series of small rooms (like the cells where monks slept in monasteries). Hooke (1665) reported,
"I took a good clear piece of Cork, and with a Pen-knife sharpen'd as keen as a Razor, I cut a piece of it off, and…cut off from the former smooth surface an exceeding thin piece of it, and…I could exceeding plainly perceive it to be all perforated and porous, much like a Honey-comb, but that the pores of it were not regular; yet it was not unlike a Honey-comb in these particulars
…these pores, or cells, were not very deep, but consisted of a great many little Boxes, separated out of one continued long pore, by certain Diaphragms, as is visible by the Figure B, which represents a sight of those pores split the long-ways.
Robert Hooke
Hooke's drawing of the 'pores' or 'cells' in cork
Components of cells
Dr. Mukherjee described how
"In my book I sort of board the cell as though it's a spacecraft, you will see that it's in fact organised into rooms and there are byways and channels and of course all of these organelles which allow it to work."
We were told that "the cell has its own skeleton", and that the organelles included the mitochondria and nuclei ,
"[mitochondria] are the energy producing organelles, they make energy in most cells, our cells for instance, in human cells. In human cells there's a nucleus, which stores DNA, which is where all the genetic information is stored."
A cell that secretes antibodies which are like harpoons or missiles that it sends out to kill a pathogen?
(Images by by envandrare and OpenClipart-Vectors from Pixabay)
Immune cells
Rutherford moved the conversation onto the immune system, prompting 'Sid' that "There's a lovely phrase you use to describe T cells, which is door to door wanderers that can detect even the whiff of an invader". Dr. Mukherjee distinguished between the cells of the innate immune system,
"Those are usually the first responder cells. In humans they would be macrophages, and neutrophils and monocytes among them. These cells usually rush to the site of an injury, or an infection, and they try to kill the pathogen, or seal up the pathogen…"
and the cells of the adaptive system, such as B cells and T cells,
"The B cell is a cell that eventually becomes a plasma cell which secretes antibodies. Antibodies, they are like harpoons or missiles which the cell sends out to kill a pathogen…
[A T cell] goes around sniffing other cells, basically touching them and trying to find out whether they have been altered in some way, particularly if they are carrying inside them a virus or any other kind of pathogen, and if it finds this pathogen or a virus in your body, it is going to go and kill that virus or pathogen"
A cell that goes around sniffing other cells, touching them? 1 (Images by allinonemovie and OpenClipart-Vectors from Pixabay)
Cells of the heart
Another topic was the work of Professor Harding on the heart. She informed listeners that heart cells did not get replaced very quickly, so that typically when a person dies half of their heart cells had been there since birth! (That was something I had not realised. It is believed that this is related to how heart cells need to pulse in synchrony so that the whole organ functions as an effective pumping device – making long lasting cells that seldom need replacing more important than in many other tissues.)
At least, this relates to the cardiomyocytes – the cells that pulse when the heart beats (a pulse that can now be observed in single cells in vitro). Professor Harding described how in the heart tissue there are also other 'supporting' cells, such as "resident macrophages" (immune cells) as well as other cells moving around the cardiomyocytes. She describe her observations of the cells in Petri dishes,
"When you look at them in the dish it's incredible to see them interact. I've got a… video [of] cardiomyocytes in a dish. The cardiomyocytes pretty much just stay there and beat and don't do anything very much, and I had this on time lapse, and you could see cells moving around them. And so, in one case, the cell (I think it was a fibroblast, it looked like a fibroblast), it came and it palpated at the cardiomyocyte, and it nipped off bits of it, it sampled bits of the cardiomyocyte, and it just stroked it all the way round, and then it was, it seemed to like it a lot.
[In] another dish I had the same sort of cardiomyocyte, a very similar cell came in, it went up to the cardiomyocyte, it touched it, and as soon as it touched it, I can only describe it as it reared up and it had, little blobs appeared all over its surface, and it rushed off, literally rushed off, although it was time lapse so it was two minutes over 24 hours, so, it literally rushed off, so what had it found, why did one like it and the other one didn't?"
Making the unfamiliar, familiar
The snippets from the broadcast that I have reported above demonstrate a wide range of ways that the unfamiliar is made familiar by describing it in terms that a listener can relate to through their existing prior knowledge and experience. In these various examples the listener is left to carry across from the analogue features of the familiar (the city, the Lego bricks, human interactions, etc.) those that parallel features of the target concept – the cell. So, for example, the listener is assumed to appreciate that cells, unlike Lego bricks, are not built up through rigid, raised lumps that fit precisely in depressions on the next brick/cell. 2
Analogies with the familiar
Hooke's original label of the cell was based on a kind of analogy – an attempt to compare what we has seeing with something familiar: "pores, or cells…a great many little Boxes". He used the familiar simile of the honeycomb (something directly familiar to many more people in the seventeenth century when food was not subject to large-scale industrialised processing and packaging).
Other analogies, metaphors and similes abound. Cells are visually like "gloopy balloons", but functionally are "building blocks" (strictly a metaphor, albeit one that is used so often it has become treated as though a literal description) which can be conceptualised as being put together "like you would build a Lego kit" (a simile) although they are neither fixed, discrete blocks of a single material, nor organised by some external builder. They can be considered conceptually as the"smallest unit of life"(though philosophers argue about such descriptions and what counts as an individual in living systems).
The machine description ("fantastical living machines") reflects one metaphor very common in early modern science and cells as "incredible cities" is also a metaphor. Whether cells are literally machines is a matter of how we extend or limit our definition of machines: cells are certainly not actually cities, however, and calling them such is a way of drawing attention to the level of activity within each (often, apparently from observation, quite static) cell. B cells secrete antibodies, which the listener is old are like (a simile) harpoons or missiles – weapons.
Skeletons of the dead
Whether "the cell has its own skeleton" is a literal or metaphorical statement is arguable. It surely would have originally been a metaphoric description – there are structures in the cell which can be considered analogous to the skeleton of an organism. If such a metaphor is used widely enough, in time the term's scope expands to include its new use – and it becomes (what is called, metaphorically) a 'dead metaphor'.
Telling stories about cells
A narrative is used to help a listener imagine the cell at the scale of "a spacecraft". This is "organised into rooms and there are byways and channels" offering an analogy for the complex internal structure of a cell. Most people have never actually boarded a spacecraft, but they are ubiquitous in television and movie fiction, so a listener can certainly imagine what this might be like.
Endoplastic reticulum? (Still from Star Trek: The Motion Picture, Paramount Pictures, 1979)
Oversimplification?
The discussion of organelles illustrates how simplifications have to be made when introducing complex material. This always brings with it dangers of oversimplification that may impede further learning, or even encourage the development of alternative conceptions. So, the nucleus does not, strictly, 'store' "all the genetic information" in a cell (mitochondria carry their own genes for example).
More seriously, perhaps, mitochondria do not "make energy". 'More seriously' as the principle of conservation of energy is one of the most basic tenets of modern science and is considered a very strong candidate for a universal law. Children are often taught in school that energy cannot be created or destroyed. Science communication which is contrary to this basic curriculum science could confuse learners – or indeed members of the public seeking to understand debates about energy policy and sustainability.
Anthropomorphising cells
Cells are not only compared to inanimate entities like balloons, building bricks, cities and spaceships. They are also described in ways that make them seem like sentient agents – agents that have experiences, and conscious intentions, just as people do. So, some immune cells are metaphorical 'first responders' and just as emergency services workers they "rush to the site" of an incident. To rush is not just to move quickly, buy to deliberately do so. (By contrast, Paul McAuley refers to "innocent" amoeboid cells that collectively form into the plasmodium of a slime mould spending most of their lives"bumbling around by themselves" before they "get together". ) The immune cells act deliberately – they "try" to kill. Other immune cells "send out" metaphorical 'missiles' "to kill a pathogen". Again this language suggests deliberate action (i.e., to send out) and purpose.
That is, what is described is not just some evolved process, but something teleological: there is a purpose to sending out antibodies – it is a deliberate act with an aim in mind. This type of language is very common in biology – even referring to the 'function' of the heart or kidney or a reflex arc could be considered as misinterpreting the outcome of evolutionary developments. (The heart pumps blood through the vascular system, but referring to a function could suggest some sense of deliberate design.)
Not all cells are equal
I wonder how many readers noticed the reference above to 'supporting' cells in the heart. Professor Harding had said
"When you look inside the [heart] tissue there are many other cells [than cardiomyocytes] that are in there, supporting it, there are resident macrophages, I think we still don't know really what they are doing in there"
Why should some heart cells be seen as more important and others less so? Presumably because 'the function' of a heart is to beat, to pump, so clearly the cells that pulse are the stars, and the other cells that may be necessary but are not obviously pulsing just a supporting cast. (So, cardiomyocytes are considered heart cells, but macrophages in the same tissue are only cells that are found in the heart, "residents" – to use an analogy of my own, like migrants that have not been offered citizenship!)3
That is, there is a danger here that this way of thinking could bias research foci leading researchers to ignore something that may ultimately prove important. This is not fanciful, as it has happened before, in the case of the brain:
"Glial cells, consisting of microglia, astrocytes, and oligodendrocyte lineage cells as their major components, constitute a large fraction of the mammalian brain. Originally considered as purely non-functional glue for neurons, decades of research have highlighted the importance as well as further functions of glial cells."
Jäkel and Dimou, 2017
The lives of cells
Narrative is used again in relation to the immune cells: an infection is presented as a kind of emergency event which is addressed by special (human like) workers who protect the body by repelling or neutralising invaders. "Sniffing" is surely an anthropomorphic metaphor, as cells do not actually sniff (they may detect diffusing substances, but do not actively inhale them). Even "touching" is surely an anthropomorphism. When we say two objects are 'touching' we mean they are in contact, as we touch things by contact. But touching is sensing, not simply adjacency.
If that seems to be stretching my argument too far, to refer to immune cells "trying to find out…" is to use language suggesting an epistemic agent that can not only behave deliberately, but which is able to acquire knowledge. A cell can only "find" an infectious agent if it is (i.e., deliberately) looking for something. These metaphors are very effective in building up a narrative for the listener. Such a narrative adopts familiar 'schemata', recognisable patterns – the listener is aware of emergency workers speeding to the scene of an incident and trying to put out a fire or seeking to diagnose a medical issue. By fitting new information into a pattern that is familiar to the audience, technical and abstract ideas are not only made easier to understand, but more likely to be recalled later.
Again, an anthropomorphic narrative is used to describe interactions between heart cells. So, a fibroblast that "palpates at" a cardiomyocyte seems to be displaying deliberate behaviour: if "nipping" might be heard as some kind of automatic action – "sampling" and "stroking" surely seem to be deliberate behaviour. A cell that "came in, it went up [to another]" seems to be acting deliberately. "Rearing up" certainly brings to mind a sentient being, like a dog or a horse. Did the cell actually 'rear up'? It clearly gave that impression to Professor Harding – that was the best way, indeed the "only" way, she had to communicate what she saw.
Again we have cells "rushing" around. Or do we? The cell that had reared up, "rushed off". Actually, it appeared to "rush" when the highly magnified footage was played at 720 times the speed of the actual events. Despite acknowledging this extreme acceleration of the activity, the impression was so strong that Professor Harding felt justified in claiming the cell "literally rushed off, although it was time lapse so it was two minutes over 24 hours, so, it literally rushed off…". Whatever it did, that looked like rushing with the distortion of time-lapse viewing, it certainly did not literally rush anywhere.
But the narrative helps motivate a very interesting question, which is why the two superficially similar cells 'behaved' ('reacted', 'responded' – it is actually difficult to find completely neutral language) so differently when in contact with a cardiomyocyte. In more anthropomorphic terms: what had these cells "found, why did one like it and the other one didn't?"
Literally speaking?
Metaphorical language is ubiquitous as we have to build all our abstract ideas (and science has plenty of those) in terms of what we can experience and make sense of. This is an iterative process. We start with what is immediately available in experience, extend metaphorically to form new concepts, and in time, once those have "settled in" and "taken root" and "firmed up" (so to speak!) they can then be themselves borrowed as the foundation for new concepts. This is true both in how the individual learns (according to constructivism) and how humanity has developed culture and extended language.
So, should science communicators (whether scientists themselves, journalists or teachers) try to limit themselves to literal language?
Even if this were possible, it would put aside some of our strongest tools for 'making the unfamiliar familiar' (to broadcast audiences, to the public, to learners in formal education). However these devices also bring risks that the initial presentations (with their simplifications and metaphors and analogies and anthropomorphic narratives…) not only engage listeners but can also come to be understood as the scientific account. That is is not an imagined risk is shown by the vast numbers of learners who think atoms want to fill their shells with octets of electrons, and so act accordingly – and think this because they believe it is what they have been taught.
Does it matter if listeners think the simplification, the analogy, the metaphor, the humanising story,… is the scientific account? Perhaps usually not in the case of the audience listening to a radio show or watching a documentary out of interest.
In education it does matter, as often learners are often expected to progress beyond these introductory accounts in their thinking, and teachers' models and metaphors and stories are only meant as a starting point in building up a formal understanding. The teacher has to first establish some kind of anchor point in the students' existing understandings and experiences, but then mould this towards the target knowledge set out in the curriculum (which is often a simplified account of canonical knowledge) before the metaphor or image or story becomes firmed-up in the learners' minds as 'the' scientific account.
'Building the Body, Opening the Heart' was a good listen, and a very informative and entertaining episode that covered a lot of ideas. It certainly included some good comparisons that science teachers might borrow. But I think in a formal educational context a science teacher would need to be more circumspect in throwing some of these metaphors out there, without then doing some work to transition from them to more technical, literal, and canonical accounts.
Jäkel S and Dimou L (2017) Glial Cells and Their Function in the Adult Brain: A Journey through the History of Their Ablation. Frontiers in Cellullar Neuroscience, 11:24. doi: 10.3389/fncel.2017.00024
1 The right hand image portrays a mine, a weapon that is used at sea to damage and destroy (surface or submarine) boats. The mine is also triggered by contact ('touch').
2 That is, in an analogy there are positive and negative aspects: there are ways in which the analogue IS like the target, and ways in which the analogue is NOT like the target. Using an analogy in communication relies on the right features being mapped from the familiar analogue to the unfamiliar target being introduced. In teaching it is important to be explicit about this, or inappropriate transfers may be made: e.g., the atom is a tiny solar system so it is held together by gravity (Taber, 2013).
3 It may be a pure coincidence in relation to the choice of term 'resident' here, but in medicine 'residents' have not yet fully qualified as specialist physicians or surgeons, and so are on placement and/or under supervision, rather than having permanent status in a hospital faculty.
Faster-than-light electrons race from a sitting start and are baked to give off light brighter than millions of suns that can be used to image tiny massage balls: A case of science communication
Keith S. Taber
(The pedantic science teacher)
Ockham's razor
Ockham's razor (also known as Occam's razor) is a principle that is sometimes applied as a heuristic in science, suggesting that explanations should not be unnecessarily complicated. Faced with a straightforward explanation, and an alternative convoluted explanation, then all other things being equal we should prefer the former – not simply accept it, but to treat is as the preferred hypothesis to test out first.
Ockham's Razor is also an ABC radio show offering "a soap box for all things scientific, with short talks about research, industry and policy from people with something thoughtful to say about science". The show used to offer recorded essays (akin to the format of BBC's A Point of View), but now tends to record short live talks.
I've just listened to an episode called The 'science donut' – in fact I listened several time as I thought it was fascinating – as in a few minutes there was much to attend to.
I approached the episode as someone with an interest in science, of course, but also as an educator with an ear to the ways in which we communicate science in teaching. Teachers do not simply present sequences of information about science, but engage pedagogy (i.e., strategies and techniques to support learning). Other science communicators (whether journalists, or scientists themselves directly addressing the public) use many of the same techniques. Teaching conceptual material (such as science principles, theories, models…) can be seen as making the unfamiliar familiar, and the constructivist perspective on how learning occurs suggests this is supported by showing the learner how that which is currently still unfamiliar, is in some way like something familiar, something they already have some knowledge/experience of.
Science communicators may not be trained as teachers, so may sometimes be using these techniques in a less considered or even less deliberate manner. That is, people use analogy, metaphor, simile, and so forth, as a normal part of everyday talk to such an extent that these tropes may be generated automatically, in effect, implicitly. When we are regularly talking about an area of expertise we almost do not have to think through what we are going to say. 1
Science communicators also often have much less information about their audience than teachers: a radio programme/podcast, for example, can be accessed by people of a wide range of background knowledge and levels of formal qualifications.
One thing teachers often learn to do very early in their careers is to slow down the rate of introducing new information, and focus instead on a limited number of key points they most want to get across. Sometimes science in the media is very dense in the frequency of information presented or the background knowledge being drawn upon. (See, for example, 'Genes on steroids? The high density of science communication'.)
A beamline scientist
Dr Emily Finch, who gave this particular radio talk, is a beamline scientist at the Australian Synchrotron. Her talk began by recalling how her family visited the Synchrotron facility on an open day, and how she later went on to work there.
She then gave an outline of the functioning of the synchrotron and some examples of its applications. Along the way there were analogies, metaphors, anthropomorphism, and dubiously fast electrons.
The creation of the god particle
To introduce the work of the particle accelerator, Dr Finch reminded her audience of the research to detect the Higgs boson.
"Do you remember about 10 years ago scientists were trying to make the Higgs boson particle? I see some nods. They sometimes call it the God particle and they had a theory it existed, but they had not been able to prove it yet. So, they decided to smash together two beams of protons to try to make it using the CERN large hadron collider in Switzerland…You might remember that they did make a Higgs boson particle".
This is a very brief summary of a major research project that involved hundreds of scientists and engineers from a great many countries working over years. But this abbreviation is understandable as this was not Dr Finch's focus, but rather an attempt to link her actual focus, the Australian Synchrotron, to something most people will already know something about.
However, aspects of this summary account may have potential to encourage the development of, or reinforce an existing, common alternative conception shared by many learners. This is regarding the status of theories.
In science, theories are 'consistent, comprehensive, coherent and extensively evidenced explanations of aspects of the natural world', yet students often understand theories to be nothing more than just ideas, hunches, guesses – conjectures at best (Taber, Billingsley, Riga & Newdick, 2015). In a very naive take on the nature of science, a scientist comes up with an idea ('theory') which is tested, and is either 'proved' or rejected.
This simplistic take is wrong in two regards – something does not become an established scientific theory until it is supported by a good deal of evidence; and scientific ideas are not simply proved or disproved by testing, but rather become better supported or less credible in the light of the interpretation of data. Strictly scientific ideas are never finally proved to become certain knowledge, but rather remain as theories. 2
In everyday discourse, people will say 'I have a theory' to mean no more that 'I have a suggestion'.
A pedantic scientist or science teacher might be temped to respond:
"no you don't, not yet,"
This is sometimes not the impression given by media accounts – presumably because headlines such as 'research leads to scientist becoming slightly more confident in theory' do not have the same impact as 'cure found', 'discovery made, or 'theory proved'.
The message that could be taken away here is that scientists had the idea that Higgs boson existed, but they had not been able to prove it till they were able to make one. But the CERN scientists did not have a Higgs boson to show the press, only the data from highly engineered detectors, analysed through highly complex modelling. Yet that analysis suggested they had recorded signals that closely matched what they expected to see when a short lived Higgs decayed allowing them to conclude that it was very likely one had been formed in the experiment. The theory motivating their experiment was strongly supported – but not 'proved' in an absolute sense.
The doughnut
Dr Finch explained that
"we do have one of these particle accelerators here in Australia, and it's called the Australian Synchrotron, or as it is affectionately known the science donut
…our synchrotron is a little different from the large hadron collider in a couple of main ways. So, first, we just have the one beam instead of two. And second, our beam is made of electrons instead of protons. You remember electrons, right, they are those tiny little negatively charged particles and they sit in the shells around the atom, the centre of the atom."
Dr Emily Finch talking on Ockham's Razor
One expects that members of the audience would be able to respond to this description and (due to previous exposure to such representations) picture images of atoms with electrons in shells. 'Shells' is of course a kind of metaphor here, even if one which with continual use has become a so-called 'dead metaphor'. Metaphor is a common technique used by teachers and other communicators to help make the unfamiliar familiar. In some simplistic models of atomic structure, electrons are considered to be arranged in shells (the K shell, the L shell, etc.), and a simple notation for electronic configuration based on these shells is still often used (e.g., Na as 2.8.1).
However, this common way of talking about shells has the potential to mislead learners. Students can, and sometimes do, develop the alternative conception that atoms have actual physical shells of some kind, into which the electrons are located. The shells scientists refer to are abstractions, but may be misinterpreted as material entities, as actual shells. The use of anthropomorphic language, that is that the electrons "sit in the shells", whilst helping to make the abstract ideas familiar and so perhaps comfortable, can reinforce this. After all, it is difficult to sit in empty space without support.
The subatomic grand prix?
Dr Finch offers her audience an analogy for the synchrotron: the electrons "are zipping around. I like to think of it kind of like a racetrack." Analogy is another common technique used by teachers and other communicators to help make the unfamiliar familiar.
Dr Finch refers to the popularity of the Australian Formula 1 (F1) Grand Prix that takes place in Melbourne, and points out
"Now what these race enthusiasts don't know is that just a bit further out of the city we have a race track that is operating six days a week that is arguably far more impressive.
That's right, it is the science donut. The difference is that instead of having F1s doing about 300 km an hour, we have electrons zipping around at the speed of light. That's about 300 thousand km per second.
Dr Emily Finch talking on Ockham's Razor
There is an interesting slippage – perhaps a deliberate rhetoric flourish – from the synchrotron being "kind of like a racetrack" (a simile) to being "a race track" (a metaphor). Although racing electrons lacks a key attraction of an F1 race (different drivers of various nationalities driving different cars built by competing teams presented in different livery – whereas who cares which of myriad indistinguishable electrons would win a race?) that does not undermine the impact of the mental imagery encouraged by this analogy.
This can be understood as an analogy rather than just a simile or metaphor as Dr Finch maps out the comparison:
target concept
analogue
a synchotron
a racetrack
operates six days a week
[Many in the audience would have known that the Melbourne Grand Prix takes place on a 'street circuit' that is only set up for racing one weekend each year.]
racing electrons
racing 'F1s' (i.e., Grand Prix cars)
at the speed of light
at about 300 km an hour
An analogy between the Australian Synchrotron and the Melbourne Grand Prix circuit
So, here is an attempt to show how science has something just like the popular race track, but perhaps even more impressive – generating speeds orders of magnitude greater than even Lewis Hamilton could drive.
They seem to like their F1 comparisons at the Australian Synchrotron. I found another ABC programme ('The Science Show') where Nobel Laureate "Brian Schmidt explains, the synchrotron is not being used to its best capability",
"the analogy here is that we invested in a $200 million Ferrari and decided that we wouldn't take it out of first gear and do anything other than drive it around the block. So it seems a little bit of a waste"
Brian Schmidt (Professor of Astronomy, and Vice Chancellor, at Australian National University)
A Ferrari being taken for a spin around the block in Melbourne (Image by Lee Chandler from Pixabay )
How fast?
But did Dr Finch suggest there that the electrons were travelling at the speed of light? Surely not? Was that a slip of the tongue?
"So, we bake our electrons fresh in-house using an electron gun. So, this works like an old cathode ray tube that we used to have in old TVs. So, we have this bit of tungsten metal and we heat it up and when it gets red hot it shoots out electrons into a vacuum. We then speed up the electrons, and once they leave the electron gun they are already travelling at about half the speed of light. We then speed them up even more, and after twelve metres, they are already going at the speed of light….
And it is at this speed that we shoot them off into a big ring called the booster ring, where we boost their energy. Once their energy is high enough we shoot them out again into another outer ring called the storage ring."
Dr Emily Finch talking on Ockham's Razor
So, no, the claim is that the electrons are accelerated to the speed of light within twelve metres, and then have their energy boosted even more.
But this is contrary to current physics. According to the currently accepted theories, and specifically the special theory of relativity, only entities which have zero rest mass, such as photons, can move at the speed of light.
Electrons have a tiny mass by everyday standards (about 0.000 000 000 000 000 000 000 000 001 g), but they are still 'massive' particles (i.e., particles with mass) and it would take infinite energy to accelerate a single tiny electron to the speed of light. So, given our current best understanding, this claim cannot be right.
I looked to see what was reported on the website of the synchrotron itself.
The electron beam travels just under the speed of light – about 299,792 kilometres a second.
Strictly the electrons do not travel at the speed of light but very nearly the speed of light.
The speed of light in a vacuum is believed to be 299 792 458 ms-1 (to the nearest metre per second), but often in science we are working to limited precision, so this may be rounded to 2.998 ms-1 for many purposes. Indeed, sometimes 3 x 108 ms-1 is good enough for so-called 'back of the envelope' calculations. So, in a sense, Dr Finch was making a similar approximation.
But this is one approximation that a science teacher might want to avoid, as electrons travelling at the speed of light may be approximately correct, but is also thought to be physically impossible. That is, although the difference in magnitude between
(i) the maximum electron speeds achieved in the synchrotron, and
(ii) the speed of light,
might be a tiny proportional difference – conceptually the distinction is massive in terms of modern physics. (I imagine Dr Finch is aware of all this, but perhaps her background in geology does not make this seem as important as it might appear to a physics teacher.)
Dr Finch does not explicitly say that the electrons ever go faster than the speed of light (unlike the defence lawyer in a murder trial who claimed nervous impulses travel faster than the speed of light) but I wonder how typical school age learners would interpret "they are already going at the speed of light….And it is at this speed that we shoot them off into a big ring called the booster ring, where we boost their energy". I assume that refers to maintaining their high speeds to compensate for energy transfers from the beam: but only because I think Dr Finch cannot mean accelerating them beyond the speed of light. 3
The big doughnut
After the reference to how "we bake our electrons fresh in-house", Dr Finch explains
And so it is these two rings, these inner and outer rings, that give the synchrotron its nick name, the science donut. Just like two rings of delicious baked electron goodness…
So, just to give you an idea of scale here, this outer ring, the storage ring, is about forty one metres across, so it's a big donut."
So, there is something of an extended metaphor here. The doughnut is so-called because of its shape, but this doughnut (a bakery product) is used to 'bake' electrons.
If audience members were to actively reflect on and seek to analyse this metaphor then they might notice an incongruity, perhaps a mixed metaphor, as the synchrotron seems to shift from being that which is baked (a doughnut) to that doing the baking (baking the electrons). Perhaps the electrons are the dough, but, if so, they need to go into the oven.
But, of course, humans implicitly process language in real time, and poetic language tends to be understood intuitively without needing reflection. So, a trope such as this may 'work' to get across the flavour (sorry) of an idea, even if under close analysis (by our pedantic science teacher again) the metaphor appears only half-baked.
Perverting the electrons
Dr Finch continued
"Now the electrons like to travel in straight lines, so to get them to go round the rings we have to bend them using magnets. So, we defect the electrons around the corners [sic] using electromagnetic fields from the magnets, and once we do this the electrons give off a light, called synchrotron light…
Dr Emily Finch talking on Ockham's Razor
Now electrons are not sentient and do not have preferences in the way that someone might prefer to go on a family trip to the local synchrotron rather than a Formula 1 race. Electrons do not like to go in straight lines. They fit with Newton's first law – the law of inertia. An electron that is moving ('travelling') will move ('travel') in a straight line unless there is net force to pervert it. 4
If we describe this as electrons 'liking' to travel in straight lines it would be just as true to say electrons 'like' to travel at a constant speed. Language that assigns human feelings and motives and thoughts to inanimate objects is described as anthropomorphic. Anthropomorphism is a common way of making the unfamiliar familiar, and it is often used in relation to molecules, electrons, atoms and so forth. Sadly, when learners pick up this kind of language, they do not always appreciate that it is just meant metaphorically!
"This synchrotron light is brighter than a million suns, and we capture it using special equipment that comes off that storage ring.
And this equipment will focus and tune and shape that beam of synchrotron light so we can shoot it at samples like a LASER."
Dr Emily Finch talking on Ockham's Razor
Whether the radiation is 'captured' is a moot point, as it no longer exists once it has been detected. But what caught my attention here was the claim that the synchrotron radiation was brighter than a million suns. Not because I necessarily thought this bold claim was 'wrong', but rather I did not understand what it meant.
The statement seems sensible at first hearing, and clearly it means qualitatively that the radiation is very intense. But what did the quantitative comparison actually mean? I turned again to the synchrotron webpage. I did not find an answer there, but on the site of a UK accelerator I found
"These fast-moving electrons produce very bright light, called synchrotron light. This very intense light, predominantly in the X-ray region, is millions of times brighter than light produced from conventional sources and 10 billion times brighter than the sun."
Sunlight spreads out and its intensity drops according to an inverse square law. Move twice as far away from a sun, and the radiation intensity drops to a quarter of what it was when you were closer. Move to ten times as far away from the sun than before, and the intensity is 1% of what it was up close.
The synchrotron 'light' is being shaped into a beam "like a LASER". A LASER produces a highly collimated beam – that is, the light does not (significantly) spread out. This is why football hooligans choose LASER pointers rather than conventional torches to intimidate players from a safe distance in the crowd.
Comparing light with like
This is why I do not understand how the comparison works, as the brightness of a sun depends how close you are too it – a point previously discussed here in relation to NASA's Parker solar probe (NASA puts its hand in the oven). If I look out at the night sky on a clear moonlight night then surely I am exposed to light from more "than a million suns" but most of them are so far away I cannot even make them out. Indeed there are faint 'nebulae' I can hardly perceive that are actually galaxies shining with the brightness of billions of suns. 5 If that is the comparison, then I am not especially impressed by something being "brighter than a million suns".
How bright is the sun? it depends which planet you are observing from. (Images by AD_Images and Gerd Altmann from Pixabay)
We are told not to look directly at the sun as it can damage our eyes. But a hypothetical resident of Neptune or Uranus could presumably safely stare at the sun (just as we can safely stare at much brighter stars than our sun because they are so far away). So we need to ask :"brighter than a million suns", as observed from how far away?
How bright is the sun? That depends on viewing conditions (Image by UteHeineSch from Pixabay)
Even if referring to our Sun as seen from the earth, the brightness varies according to its apparent altitude in the sky. So, "brighter than a million suns" needs to be specified further – as perhaps "more than a million times brighter than the sun as seen at midday from the equator on a cloudless day"? Of course, again, only the pedantic science teacher is thinking about this: everyone knows well enough what being brighter than a million suns implies. It is pretty intense radiation.
Applying the technology
Dr Finch went on to discuss a couple of applications of the synchrotron. One related to identifying pigments in art masterpieces. The other was quite timely in that it related to investigating the infectious agent in COVID.
"Now by now you have probably seen an image of the COVID virus – it looks like a ball with some spikes on it. Actually it kind of looks like those massage balls that your physio makes you buy when you turn thirty and need to to ease all your physical ailments that you suddenly have."
Dr Emily Finch talking on Ockham's Razor
Coronavirus particles and massage balls…or is it… (Images by Ulrike Leone and Daniel Roberts from Pixabay)
Again there is an attempt to make the unfamiliar familiar. These microscopic virus particles are a bit like something familiar from everyday life. Such comparisons are useful where the everyday object is already familiar.
By now I've seen plenty of images of the coronavirus responsible for COVID, although I do not have a physiotherapist (perhaps this is a cultural difference – Australians being so sporty?) So, I found myself using this comparison in reverse – imagining that the "massage balls that your physio makes you buy" must be like larger versions of coronavirus particles. Having looked up what these massage balls (a.k.a. hedgehog balls it seems) look like, I can appreciate the similarity. Whether the manufacturers of massage balls will appreciate their products being compared to enormous coronavirus particles is, perhaps, another matter.
Work cited:
Taber, K. S., Billingsley, B., Riga, F., & Newdick, H. (2015). English secondary students' thinking about the status of scientific theories: consistent, comprehensive, coherent and extensively evidenced explanations of aspects of the natural world – or just 'an idea someone has'. The Curriculum Journal, 1-34. doi: 10.1080/09585176.2015.1043926
Notes:
1 At least, depending how we understand 'thinking'. Clearly there are cognitive processes at work even when we continue a conversation 'on auto pilot' (to employ a metaphor) whilst consciously focusing on something else. Only a tiny amount of our cognitive processing (thinking?) occurs within conscousness where we reflect and deliberate (i.e., explicit thinking?) We might label the rest as 'implicit thinking', but this processing varies greatly in its closeness to deliberation – and some aspects (for example, word recognition when listening to speech; identifying the face of someone we see) might seem to not deserve the label 'thinking'?
2 Of course the evidence for some ideas becomes so overwhelming that in principle we treat some theories as certain knowledge, but in principle they remain provisional knowledge. And the history of science tells us that sometimes even the most well-established ideas (e.g., Newtonian physics as an absolutely precise description of dynamics; mass and energy as distinct and discrete) may need revision in time.
3 Since I began drafting this article, the webpage for the podcast has been updated with a correction: "in this talk Dr Finch says electrons in the synchrotron are accelerated to the speed of light. They actually go just under that speed – 99.99998% of it to be exact."
4 Perversion in the sense of the distortion of an original course
5 The term nebulae is today reserved for clouds of dust and gas seen in the night sky in different parts of our galaxy. Nebulae are less distinct than stars. Many of what were originally identified as nebulae are now considered to be other galaxies immense distances away from our own.
One of the recurring themes in this blog is the way science is communicated in teaching and through media, and in particular the role of language choices, in effective communication.
I was listening to a podcast of the BBC Science in Action programme episode 'Radioactive Red Forest'. The item that especially attracted my attention (no, not the one about teaching fish to do sums) was summarised on the website as:
"Understanding the human genome has reached a new milestone, with a new analysis that digs deep into areas previously dismissed as 'junk DNA' but which may actually play a key role in diseases such as cancer and a range of developmental conditions. Karen Miga from the University of California, Santa Cruz is one of the leaders of the collaboration behind the new findings."
Website description of an item on 'Science in Action'
They've really sequenced the human genome this time
The introductory part of this item is transcribed below.
Being 'once a science teacher, always a science teacher' (in mentality, at least), I reflected on how this dialogue is communicating important ideas to listeners. Before I comment in any detail, you may (and this is entirely optional, of course) wish to read through and consider:
What does a listener (reader) need to know to understand the intended meanings in this text?
What 'tactics', such as the use of figures of speech, do the speakers use to support the communication process?
Roland Pease (Presenter): "Good news! They sequenced, fully sequenced, the human genome.
'Hang on a minute' you cry, you told us that in 2000, and 2003, and didn't I hear something similar in 2013?' Well, yes, yes, and yes, but no.
A single chromosome stretched out like a thread of DNA could be 6 or 8 cm long. Crammed with three hundred million [300 000 000] genetic letters. But to fit one inside a human cell, alongside forty five [45] others for the complete set, they each have to be wound up into extremely tight balls. And some of the resulting knots it turns out are pretty hard to untangle in the lab. and the genetic patterns there are often hard to decode as well. Which is what collaboration co-leader Karen Miga had to explain to me, when I also said 'hang on a minute'."
Karen Miga: "The celebrated release of the finished genome back in 2003 was really focused on the portions that we could at the time map and assemble. But there were big persistent gaps. Roughly about two hundred million [200 000 000] bases long that were missing. It was roughly eight percent [8%] of the genome was missing."
"And these were sort of hard to get at bits of genome, I mean are they like trying to find a coin in the bottom of your pocket that you can't quite pull out?"
"These regions are quite special, we think about tandem repeats or pieces of sequences that are found in a head-to-tail orientation in the genome, these are corners of our genome where this is just on steroids, where we see a tremendous amount of tandem repeats sometimes extending for ten million [10 000 000] bases. They are just hard to sequence, and they are hard to put together correctly and that was – that was the wall that the original human genome project faced."
Introduction to the item on the sequencing of what was known as 'junk DNA' in the (a) human genome
I have sketched out a kind of 'concept map' of this short extract of dialogue:
A mapping of the explicit connections in the extract of dialogue (ignoring connections and synonyms that a knowledgeable listener would have available for making sense of the talk)
In educational settings, teachers' presentations are informed by background information about the students' current levels of knowledge. In particular, teachers need to be aware of the 'prerequisite knowledge' necessary for understanding their presentations. If you want to be understood, then it is important your listeners have available the ideas you will be relying on in your account.
A scientist speaking to the public, or a journalist with a public audience, will be disadvantaged in two ways compared to the situation of a teacher. The teacher usually knows about the class, and the class is usually not as diverse as a public audience. There might be a considerable diversity of knowledge and understanding among the members of, say, the 13-14 year old learners in one school class, or the first year undergraduates on a university course – but how much more variety is found in the readership of a popular science magazine or the audience of a television documentary or radio broadcast.
Here are some key concepts referenced in the brief extract above:
bases
cells
chromosome
DNA
sequencing
tandem repeats
the human genome
To follow the narrative, one needs to appreciate relationships among these concepts (perhaps at least that chromosomes are found in cells; and comprised of DNA, the structure of which includes a number of different components called bases, the ordering of which can be sequenced to characterise the particular 'version' of DNA that comprises a genome. 1 ) Not all of these ideas are made absolutely explicit in the extract.
The notion of tandem repeats requires somewhat more in-depth knowledge, and so perhaps the alternative offered – tandem repeats or pieces of sequences that are found in a head to tail orientation in the genome – is intended to introduce this concept for those who are not familiar with the topic in this depth.
The complete set?
The reference to "A single chromosome stretched out…could be 6 or 8 cm long…to fit one inside a human cell, alongside forty five others for the complete set…" seems to assume that the listener will already know, or will readily appreciate, that in humans the genetic material is organised into 46 chromosomes (i.e., 23 pairs).
Arguably, someone who did not know this might infer it from the presentation itself. Perhaps they would. The core of the story was about how previous versions of 'the' [see note 1] human genome were not complete, and how new research offered a more complete version. The more background a listener had regarding the various concepts used in the item, the easier it would be to follow the story. The more unfamiliar ideas that have to be coordinated, the greater the load on working memory, and the more likely the point of the item would be missed.2
Getting in a tangle
A very common feature of human language is its figurative content. Much of our thinking is based on metaphor, and our language tends to be full [sic 3] of comparisons as metaphors, similes, analogies and so forth.
So, we can imagine 'a single chromosome' (something that is abstract and outside of most people's direct experience) as being like something more familiar: 'like a thread'. We can visualise, and perhaps have experience of, threads being 'wound up into extremely tight balls'. Whether DNA strands in chromosomes are 'wound up into extremely tight balls' or are just somewhat similar to thread wound up into extremely tight balls is perhaps a moot point: but this is an effective image.
And it leads to the idea of knots that might be pretty hard to untangle. We have experience of knots in thread (or laces, etc.) that are difficult to untangle, and it is suggested that in sequencing the genome such 'knots' need to be untangled in the laboratory. The listener may well be visualising the job of untangling the knotted thread of DNA – and quite possibly imaging this is a realistic representation rather than a kind of visual analogy.
Indeed, the reference to "some of the resulting knots it turns out are pretty hard to untangle in the lab. and the genetic patterns there are often hard to decode as well" might seem to suggest that this is not an analogy, but two stages of a laboratory process – where the DNA has to be physically untangled by the scientists before it can be sequenced, but that even then there is some additional challenge in reading the parts of the 'thread' that have been 'knotted'.
Reading the code
In the midst of this account of the knotted nature of the chromosome, there is a complementary metaphor. The single chromosome is "crammed with three hundred million genetic letters". The 'letters' relate to the code which is 'written' into the DNA and which need to be decoded. An informed listener would know that the 'letters' are the bases (often indeed represented by the letters A, C, G and T), but again it seems to be assumed this does not need to be 'spelt out'. [Sorry.]
But, of course, the genetic code is not really a code at all. At least, not in the original meaning of a means of keeping a message secret. The order of bases in the chromosome can be understood as 'coding' for the amino acid sequences in different proteins but strictly the 'code' is, or at least was originally, another metaphor. 4
Hitting the wall
The new research had progressed beyond the earlier attempts to sequence the human genome because that project had 'faced a wall' – a metaphorical wall, of course. This was the difficulty of sequencing regions of the genome that, the listener is told, were quite special.
The presenter suggests that the difficulty of sequencing these special regions of "hard to get at bits of genome" was akin to" trying to find a coin in the bottom of your pocket that you can't quite pull out". This is presumably assumed to be a common experienced shared by, or at least readily visualised by, the audience allowing them to better appreciate just how "hard to get at" these regions of the genome are.
We might pause to reflect on whether a genome can actually have regions. The term region seems to have originally been applied to a geographical place, such as part of a state. So, the idea that a genome has regions was presumably first used metaphorically, but this seems such a 'natural' transfer, that the 'mapping' seems self-evident. If it was a live metaphor, it is a dead one now.
Similarly, the mapping of the sequences of fragments of chromosomes onto the 'map' of the genome seems such a natural use of the term may no longer seem to qualify as a metaphor.
Repeats on steroids
These special regions are those referred to above as having tandem repeats – so parts of a chromosome where particular base sequences repeat (sometimes a great many times). This is described as "pieces of sequences that are found in a head to tail orientation" – applying an analogy with an organism which is understood to have a body plan that has distinct anterior and posterior 'ends'.
Not only does the genome contain such repeats, but in some places there are a 'tremendous' number of these repeats occurring head to tail. These places are referred to as 'corners' of the genome (a metaphor that might seem to fit better with the place in a pocket where a coin might to be hard to dislodge – or perhaps associated with that wall), than with a structure said to be like a knotted, wound-up, ball of thread.
It is suggested that in these regions, the repeats of the same short base sequences can be so extensive that they continue for billions of bases. This is expressed through the simile that the tandem repeating "is just on steroids" – again an allusion to what is assumed to be a familiar everyday phenomenon, that is, something familiar enough to people listening to help then appreciate the technical account.
Many people in the audience will have experience of being on steroids as steroids are prescribed for a wide variety of inflammatory conditions – both acute (due to accidents or infections) and chronic (e.g., asthma). Yet these are corticosteroids and 'dampen down' (metaphorically, of course) inflammation. The reference here is to anabolic steroid use, or rather abuse, by some people attempting to quickly build up muscle mass. Although anabolic steroids do have clinical use, abusers may take doses orders of magnitude higher than those prescribed for medical conditions.
I suspect that whereas many people have personal experience or experience of close family being on corticosteroids, whereas anabolic steroid use is rarer, and is usually undertaken covertly – so the metaphor here lies on cultural knowledge of the idea of people abusing anabolic steroids leading to extreme physical and mood changes.
Making a good impression
That is not to suggest this metaphor does not work. Rather I would suggest that most listeners would have appreciated the intended message implied by 'on steroids', and moreover the speaker was likely able to call upon the metaphor implicitly – that is without stopping to think about how the metaphor might be understood.
Metaphors of this kind can be very effective in giving an audience a strong impression of the scientific ideas being presented. It is worth noting, though, that what is communicated is to some extent just that, an impression, and this kind of impressionist communication contrasts with the kind of technically precise language that would be expected in a formal scientific communication.
Language on steroids
Just considering this short extract from this one item, there seems to be a great deal going on in the communication of the science. A range of related concepts are drawn upon as (assumed) background and a narrative offered for why the earlier versions of the human genome were incomplete, and how new studies are producing more complete sequences.
Along the way, communication is aided by various means to help 'make the unfamiliar familiar' by using both established metaphors as well as new comparisons. Some originally figurative language (mapping, coding, regions) is now so widely used it has been adopted as literally referring to the genome. Some common non-specific metaphors are used (hitting a wall, hard to access corners), and some specific images (threads, knots and tangles, balls, head-tails) are drawn upon, and some perhaps bespoke comparisons are introduced (the coin in the pocket, being on steroids).
In this short exchange there is a real mixture of technical language with imagery, analogy, and metaphor that potentially both makes the narrative more listener-friendly and helps bridge between the science and the familiar everyday – at last when these figures of speech are interpreted as intended. This particular extract seems especially 'dense' in the range of ideas being orchestrated into the narrative – language on steroids, perhaps – but I suspect similar combinations of formal concepts and everyday comparisons could be found in many other cases of public communication of science.
An alternative concept map of the extract, suggesting how someone with some modest level of background in the topic might understand the text (filling in some implicit concepts and connections). How a text is 'read' always depends upon the interpretive resources the listener/reader brings to the text.
At least the core message was clear: Scientists have now fully sequenced the human genome.
Although, I noticed when I sought out the scientific publication that "the total number of bases covered by potential issues in the T2T-CHM13 assembly [the new research] is just 0.3% of the total assembly length compared with 8% for GRCh38 [The human genome project version]" (Nurk et al., 2022) , which, if being churlish, might be considered not entirely 'fully' sequenced. Moreover "CHM13 lacks a Y chromosome", which – although it is also true of half of the human population – might also suggest there is still a little more work to be done.
Work cited:
Nurk, S., Koren, S., Rhie, A., Rautiainen, M., Bzikadze, A. V., Mikheenko, A., . . . Phillippy, A. M.* (2022). The complete sequence of a human genome. Science, 376(6588), 44-53. doi:doi:10.1126/science.abj6987
Notes
1 We often talk of DNA as a substance, and a molecule of DNA as 'the' DNA molecule. It might be more accurate to consider DNA as a class of (many) similar substances each of which contains its own kind of DNA molecule. Similarly, there is not a really 'a' human genome – but a good many of them.
2 Working memory is the brain component where people consciously access and mentipulate information, and it has a very limited capacity. However, material that has been previously learnt and well consolidated becomes 'chunked' so can be accessed as 'chunks'. Where concepts have been integrated into coherent frameworks, the whole framework is accessed from memory as if a single unit of information.
3 Strictly only a container can be full – so, this is a metaphor. Language is never full -as we can always be more verbose! Of course, it is such a familiar metaphor that it seems to have a literal meaning. It has become what is referred to as a 'dead' metaphor. And that is, itself, a metaphor, of course.
4 Language changes over time. If we accept that much of human cognition is based on constructing new ways of thinking and talking by analogy with what is already familiar (so the song is on the 'top' of the charts and it is a 'long' time to Christmas, and a 'hard' rain is going to fall…) then language will grow by the adoption of metaphors that in time cease to be seen as metaphors, and indeed may change in their usage such that the original reference (e.g., as with electrical 'charge') may become obscure.
In education, teachers may read originally metaphorical terms in terms of teir new scientific meanings, whereas learners may understand the terms (electron 'spin', 'sharing' of electrons, …) in terms of the metaphorical/analogical source.
*This is an example of 'big science'. The full author list is:
Sergey Nurk, Sergey Koren, Arang Rhie, Mikko Rautiainen, Andrey V. Bzikadze, Alla Mikheenko, Mitchell R. Vollger, Nicolas Altemose, Lev Uralsky, Ariel Gershman, Sergey Aganezov, Savannah J. Hoyt, Mark Diekhans, Glennis A. Logsdon,p Michael Alonge, Stylianos E. Antonarakis, Matthew Borchers, Gerard G. Bouffard, Shelise Y. Brooks, Gina V. Caldas, Nae-Chyun Chen, Haoyu Cheng, Chen-Shan Chin, William Chow, Leonardo G. de Lima, Philip C. Dishuck, Richard Durbin, Tatiana Dvorkina, Ian T. Fiddes, Giulio Formenti, Robert S. Fulton, Arkarachai Fungtammasan, Erik Garrison, Patrick G. S. Grady, Tina A. Graves-Lindsay, Ira M. Hall, Nancy F. Hansen, Gabrielle A. Hartley, Marina Haukness, Kerstin Howe, Michael W. Hunkapiller, Chirag Jain, Miten Jain, Erich D. Jarvis, Peter Kerpedjiev, Melanie Kirsche, Mikhail Kolmogorov, Jonas Korlach, Milinn Kremitzki, Heng Li, Valerie V. Maduro, Tobias Marschall, Ann M. McCartney, Jennifer McDaniel, Danny E. Miller, James C. Mullikin, Eugene W. Myers, Nathan D. Olson, Benedict Paten, Paul Peluso, Pavel A. Pevzner, David Porubsky, Tamara Potapova, Evgeny I. Rogaev, Jeffrey A. Rosenfeld, Steven L. Salzberg, Valerie A. Schneider, Fritz J. Sedlazeck, Kishwar Shafin, Colin J. Shew, Alaina Shumate, Ying Sims, Arian F. A. Smit, Daniela C. Soto, Ivan Sović, Jessica M. Storer, Aaron Streets, Beth A. Sullivan, Françoise Thibaud-Nissen, James Torrance, Justin Wagner, Brian P. Walenz, Aaron Wenger, Jonathan M. D. Wood, Chunlin Xiao, Stephanie M. Yan, Alice C. Young, Samantha Zarate, Urvashi Surti, Rajiv C. McCoy, Megan Y. Dennis, Ivan A. Alexandrov, Jennifer L. Gerton, Rachel J. O'Neill, Winston Timp, Justin M. Zook, Michael C. Schatz, Evan E. Eichler, Karen H. Miga, Adam M. Phillippy
Some spider monkeys like a little something extra with "all this fruit"
Keith S. Taber
(Photograph by by Manfred Richter from Pixabay)
"oh heck, what am I going to do, I'm faced with all this fruit with no protein and I've got to be a spider monkey"
Primatologist Adrian Barnett getting inside the mind of a monkey
I was listening to an item on the BBC World Service 'Science in Action' programme/podcast (an episode called 'Climate techno-fix would worsen global malaria burden').
This included an item with the title:
Primatologist Adrian Barnett has discovered that spider monkeys in one part of the Brazilian Amazon seek out fruit, full of live maggots to eat. Why?
The argument was that the main diet of monkeys is usually fruit which is mostly very low in protein and fat. However, often monkeys include figs in their diet which are an exception, being relatively rich in protein and fats.
The spider monkeys in one part of the Amazon, however, seem to 'seek out' fruit that was infested with maggots – these monkeys appear to actively choose the infected fruits. These are the fruits a human would probably try to avoid: certainly if there were non-infested alternatives. Only a proportion of fruit on the trees are so infested, yet the monkeys consume a higher proportion of infested fruit and so seem to have a bias towards selecting fruit with maggots. At least that was what primatologist Dr Adrian Barnett's analysis found when he analysed the remains of half-eaten fruit that reached the forest floor.
The explanation suggested is that this particular area of forest has very few fig trees, therefore it seems these monkeys do not have ready access to figs, and it seems they instead get a balanced diet by preferentially picking fruit containing insect larvae.
Who taught the monkeys about their diet?
A scientific explanation of this might suggest natural selection was operating.
Even if monkeys had initially tended to avoid the infested fruit, if this then led to a deficient diet (making monkeys more prone to disease, or accidents, and less fertile) then any monkeys who supplemented the fruit content of their diet by not being so picky and eating some infested fruit (whether because of a variation in their taste preferences, or simply a variation in how careful they were to avoid spoilt fruit) would have a fitness advantage and so, on average, leave more offspring.
To the extent their eating habits reflected genetic make-up (even if this was less significant for variations in individual behaviour than contingent environmental factors) this would over time shift the typical behaviours in the population. Being willing to eat, or perhaps even enjoying, maggotty fruit was likely to be a factor in being fertile and fecund, so eventually eating infested fruit becomes the norm – at least as long as the population remains in a habitat that does not have other ready sources of essential dietary components. Proving this is what happened would be very difficult after the fact. But an account along these lines is consistent with our understanding of how behaviour tends to change.
An important aspect of natural selection is that it is an automatic process. It does not require any deliberation or even conscious awareness on behalf of the members of the population being subject to selection. Changes do not occur in response to any preference or purpose – but just reflect the extent to which different variants of a population match their environment.
This is just as well, as even though monkeys are primates, and so relatively intelligent animals, it seems reasonable to assume they do not have a formal concept of diet (rather, they just eat), and they are not aware of the essential need for fat and protein in the diet; nor of the dietary composition of fruit. Natural selection works because where there is variation, and differences in relative fitness, the fittest will tend to leave more offspring (as by fittest we simply mean those most able to leave offspring!)
Now he's thinking…
I was therefore a little surprised when the scientist being interviewed, Adrian Barnett, explained the behaviour:
"So, suddenly the monkey's full of, you know, squeaking the monkey equivalent of 'oh heck, what am I going to do, erm, I'm faced with all this fruit with no protein and I've got to be a spider monkey'."
Adrian Barnett speaking on Science in Action
At first hearing this sounds like anthropomorphism, where non-humans are assigned human feelings and cognitions.
Anthropomorphic language refers to non-human entities as if they have human experiences, perceptions, and motivations. Both non-living things and non-human organisms may be subjects of anthropomorphism. Anthropomorphism may be used deliberately as a kind of metaphorical language that will help the audience appreciate what is being described because of its similarly to some familiar human experience. In science teaching, and in public communication of science, anthropomorphic language may often be used in this way, giving technical accounts the flavour of a persuasive narrative that people will readily engage with. Anthropomorphism may therefore be useful in 'making the unfamiliar familiar', but sometimes the metaphorical nature of the language may not be recognised, and the listener/reader may think that the anthropomorphic description is meant to be taken at face value. This 'strong anthropomorphism' may be a source of alternative conceptions ('misconceptions') of science.
Why 'at first hearingthis seems like an example of anthropomorphism'? Well, Dr Barnett does not say the monkey actually has these thoughts but rather squeaks the monkey equivalent of these words. This leaves me wondering how we are to understand what the monkey equivalent actually is. I somehow suspect that whatever thoughts the monkey has they probably do not include any direct equivalents of either being a spider monkey or protein.
I am happy to accept the monkey has a concept somewhat akin to our fruit, as clearly the monkey is able to discriminate particular regularities in its environment that are associated with the behaviour of picking items from trees and eating them – regularities that we would class as fruit. It is interesting to speculate on what would be included in a monkey's concept map of fruit, were one able to induce a monkey to provide the data that might enable us to produce such a diagram. Perhaps there might be monkey equivalents of such human concepts as red and crunchy and mushy…but I would not be expecting any equivalents of our concepts of dietary components or nutritional value.
So, although I am not a primatologist, I wonder if the squeaking Dr Barnett heard when he was collecting for analysis the partially eaten fruit dropped by the spider monkeys was actually limited to the monkey equivalent of either "yummy, more fruit" or perhaps "oh, fruit again".
Taking advantage of good design? (Image by Ben Kerckx from Pixabay )
"A lot of researchers talk about this [neural system] called the care-giving system which is designed to help us care for our crying babies".
Assoc. Prof. Sara Konrath
The reference to the 'design' of a human neural system caught my attention. The reference was made by Dr Sara Konrath, Associate Professor of Philanthropic Studies at the Lilly Family School of Philanthropy at Indiana University, who was interviewed for the BBC radio programme 'The Anatomy of Kindness'.
As a scientist, I found the reference to 'design' out of place, as it is a term that would often be avoided in a scientific account.
Mention of 'design' in the context of natural phenomena is of note because of the history of the idea, and its role in key philosophical questions (such as the nature of the world, the purpose of our lives, the origins of good and evil, and other such trifling matters).
The notion of design was very important in natural theology, which looked at 'the book of nature' as God's works, and as offering insight into God as creator. A key argument was that the intricacy of nature, and the way life seemed to encompass such complex interlinked systems that perfectly fitted together into an overarching ecology, could only be explained in terms of a designer who was the careful architect of the whole creation.
Perhaps the most famous example of this argument was that of William Paley who wrote an entire book (1802) making the case with a vast range of examples. He started with the now famous analogy of someone who found a pocket watch on crossing a heath. Had he kicked a stone on his trip, he would have thought little of how the stone came to be there – but a watch was a complex mechanism requiring a large number of intricate parts that had to be just the right size, made of the right kind of materials, and put together in just the right way to function. No reasonable person could imagine the watch had just happened to come about by chance events, and so, by a similar argument, how could anything as subtle and complex as a human body have just emerged by accident and not have been designed by some great intelligence?
If you came across this object lying on the ground, what might you infer? (Image by anncapictures from Pixabay)
Paley's book does a wonderful job of arguing the case, and, even if some of the examples look naive from two centuries on, it was the work of someone who knew a great deal about anatomy, and the natural history of his time, and knew how to build up 'one long argument'. 1 It must have seemed very convincing to many readers at the time (especially as most would have read it from a position of already assuming there was an omniscient and all-powerful creator, and that the types of animals and plants on earth had not substantially changed their forms since their creation).
Indeed, a fair proportion of the world's population would still consider the argument sound and convincing today. That is despite Charles Darwin having suggested, about half a century later, in his own long argument 1 that there was another alternative (than an intelligent designer or simply chance formation of complex organisms and ecosystems). The title of one of Richard Dawkin's most famous books, The Blind Watchmaker (1988), championing the scientific position first developed by Darwin (and Alfred Russel Wallace) is a direct reference to Paley's watch on the heath.
The modern scientific view, supported by a vast amount of evidence from anatomy, genetics, paleontology, geology and other areas is that life evolved on earth over a vast amount of time from common ancestral unicellular organisms (which it is thought themselves evolved from less complex systems over a very long period).
Has science ruled out design?
This does not mean that science has completely ruled out the possibility that modern life-forms could have been designed. Science does rule out the possibility that modern organisms were created 'as is' (i.e., 'as are'), so if they were designed then the designer not only designed their forms, but also the highly complex processes by which they might evolve and the contingencies which made this possible. (That can be seen as an even greater miracle, and even stronger evidence of God's capabilities, of course.) What science does not do is to speculate on first causes which are not open to scientific investigation. 2
Many of the early modern scientists had strong religious convictions – including faith in an intelligent creator – and saw science as work that was totally in keeping with their faith, indeed often as a form of observance: a way of exploring and wondering at God's work. Science, philosophy and theology were often seen as strongly interlinked.
However, the usual expectation today is that science, being the study of nature, has no place for supernatural explanations. Scientists are expected to adopt 'methodological naturalism', which means looking for purely natural mechanisms and causes. 3
Arguments from design invoke teleology, the idea that nature has purpose. This makes for lazy science – as we do not need to seek natural mechanisms and explanations if we simply argue that
the water molecule was designed to be a shape to form hydrogen bonds, or that
copper is a good conductor because its molecular structure was designed for that purpose, or that
uranium is subject to radioactive decay because the nucleus of a uranium atom was designed to be unstable
Science has (and so a scientist, when doing her science, should have) nothing to say about the existence of a creator God, and has no view on whether aspects of the natural world might reflect such a creator's design; so arguments from design have no place in scientific accounts and explanations. This is why I honed in on the reference to design.
The evolution of empathy?
The reference was in relation to empathy. The presenter, Dr Claudia Hammond, asked rhetorically "empathy … how did it evolve?", and then introduced an interview clip: "Here's Sara Konrath, Associate Professor at the Lilly Family School of Philanthropy at Indiana University in the U.S." This was followed by Dr Konrath stating:
"A lot of researchers talk about this thing called the care-giving system which is designed to help us care for our crying babies. So, think about a crying baby for a minute that is not your own. You are on an airplane, think about that. [She laughs] And probably what you are hoping for is that baby will stop crying, [Hammond: 'absolutely'], I guess.
We need to have a biological system that will make us feel compassion for that little crying baby and figure out what's wrong so we can make the baby feel better. So, there's a whole neural system that's called the care-giving system, that activates oxytocin which is a hormone that helps us to basically reduce stress and feel close and connected, and as you can imagine that would help us want to change that little nappy or whatever the baby needs. * And that same brain system doesn't seem to distinguish too much, well, you know, we can use that, that same system to care for other people in our lives that we know or even strangers, and even people who are different than us."
Assoc. Prof. Sara Konrath
Now, as pointed out above, accepting evolution (as the vast majority of natural scientists do) does not logically exclude design – but to be consistent it requires the design not only of the intended structure, but also of the entire natural system which will give rise to it. And evolution, a natural process, is open to scientific investigation, whereas claims of design rely on extra-scientific considerations. Moreover, as evolution is an ongoing process, one might suggest that references to 'this stage in the design-realisation process' might be more appropriate.
One way of explaining the apparent inconsistency here ("how did it evolve?"…"designed to help us") is to simply assume that I am being much too literal, as surely Dr Konrath was speaking metaphorically. We can talk about 'the design' of the kidney, or a flower, or of a cow's digestive system, meaning the structure, the layout, the assemblage – without meaning to suggest 'the design' had been designed. Although Dr Konrath referred to the neural system being designed, it is quite possible she was speaking metaphorically.
But can we beleive what we (think we) hear?
A listener can reasonably assume, from the editing of the programme, that Dr Konrath was asked, and was answering, the question 'how did empathy evolve?' Yet this is only implied ("…how did it evolve? Here's Sara Konrath…") – the clip of Dr Konrath does not include any interview questions.
A journalist has to edit a programme together, to offer a narrative a listener can easily follow, so it is likely an interview would be edited down to select the most useful material. Indeed, when transcribing, I suspected that there was an edit at the point I have marked * above. I could not hear any evidence of an edit, BUT to my ears the speech was not natural in moving between "…whatever the baby needs" and "And that same brain system…". Perhaps I am wrong. But, perhaps there was a pause, or a 'false start', edited out to tidy the clip; or perhaps some material deemed less pertinent or too technical for present purposes was removed. Or, possibly, the order of the material has been changed if the speaker had responded to a number of questions, and it was felt a re-ordering of segments of different responses offered a better narrative.
All of that would be totally acceptable, as long as it was done without any intention to distort what the speaker had said. Indeed, in analysing and presenting research material from interviews or written texts, one approach is known as editing. 4 I have used this myself, to select text from different points in an interview to build up a narrative that can summarise an informant's ideas succinctly (e.g., Taber, 2008 5). This needs to be done carefully, but as long as an effort is made to be true to the person's own ideas (as the researcher understands them from the data) and this methodological technique is explicitly reported to readers, it is a valid approach and can be very effective.
Perhaps, if Dr Konrath was indeed asked 'how did empathy evolve?' this was a rather unfair question. Unlike some anatomical structures, empathy does not leave direct evidence in the fossil record. This might explain a not entirely convincing response.
The gist of the clip, as I assume a listener was meant to understand it, was along the lines.
How did empathy evolve?
babies cannot look after themselves and need support
they cry to get attention when they need help
a system evolved to ensure that others around the baby would pay attention to its cries, and feel compassionate, and so help it
the system either has the side effect of, or has evolved over time, allowing us to be empathetic more generally so we support people who need help
Perhaps that narrative is correct, and perhaps there is even scientific evidence for it. But, in terms of what I actually hear Dr Konrath say, I do not find a strong evolutionary account, but rather something along the lines:
We have a biological system known as the care-giving system, that activates a hormone that reduces stress and helps us feel close and connected to others
this allows us to feel compassion for people in need
encouraging us to care for other people, largely indiscriminately
even strangers, such as a crying baby
When I reframe ('edit') the interview that way, I do not see any strong case for why this system is designed specifically to help us care for our crying babies – but nor is there any obvious evolutionary argument. 6
If one approaches this description with a prior assumption that such things have evolved through natural selection then Dr Konrath's words can certainly be readily interpreted to be consistent with an evolutionary narrative. 6 However, someone who did not accept evolution and had a metaphysical commitment to seeing the natural world as evidence for a designer would surely be able to understand the interview just as well within that frame. I suspect both Paley and Darwin would have been able to work this material into their arguments.
Works cited:
Darwin, C. (1859/2006). The Origin of Species. In E. O. Wilson (Ed.), From so Simple a Beginning: The four great books of Charles Darwin. New York: W. W. Norton.
Dawkins, R. (1988). The Blind Watchmaker. Harmondsworth, Middlesex: Penguin Books.
Paley, W. (1802/2006). Natural Theology: Or Evidence of the Existence and Attributes of the Deity, Collected from the Appearances of Nature (M. D. Eddy & D. Knight Eds.). Oxford: Oxford University Press.
Taber, K. S. (2008). Exploring Conceptual Integration in Student Thinking: Evidence from a case study. International Journal of Science Education, 30 (14), 1915-1943. (DOI: 10.1080/09500690701589404.)
1 The term 'one long argument' was used by Darwin to describe his thesis in the Origin of Species.
2 I write loosely here: science does not do anything; rather, it is scientists that act. Yet it would not be true to claim scientists do not speculate on first causes which are not open to scientific investigation. Many of them do. (Dawkins, for example, seems very certain there is no creator God.) However, that is because scientists are people and so have multiple identities. Just as nothing stops a scientist also being a mother or a daughter; nothing stops them being ice skaters, break dancers or poets. So, scientists do speculate outside of the natural realm – but then they are doing something other than science, as when they write limericks. (And perhaps something where their scientific credentials suggest no special expertise.)
3 Unfortunately, this can mislead learners into thinking science is atheistic and scientists necessarily atheists:
"The tradition in Western science (with its tendencies towards an analytical and reductionist approach) to precede as though the existence and potential role of God in nature is irrelevant to answering scientific questions, if not explicitly explained to students, may well give the impression that because science (as a socio-cultural activity) does not need to adopt the hypothesis of the divine, scientists themselves (as individuals sharing membership of various social groups with their identities as scientists) eschew such an idea."
4 This process would need to be made explicit in research, where it is normally just accepted as standard practice in journalism. These two activities can be seen as quite similar, especially when research is largely based on reports from various informants. A major difference however is that whereas researchers often have months to collect, analyse and report data, journalists are often expected to move on to the next story or episode within days, so may be working under considerable time pressures.
5 For example,
"Firstly the interview transcript was reworked into a narrative account of the interview based around Alice's verbatim responses, but following the chronology of the interview schedule in the order of the questions….The next stage of the analysis involved reorganising the case material into themes in terms of the main concepts used in Alice's explanations…This process produced a case account that was reduced (in this case to about 1,000 words), and which summarises the ways Alice used ideas in her interview."
Taber, 2008: 1926
6 One can imagine researchers asking themselves how this indiscriminate system for helping others in need arose, and someone suggesting that perhaps it was originally to make sure mothers attended to their own babies, but as a 'false negative' would be so costly (if you do not notice your baby is unfed, or has fallen in the lake, or is playing with the tiger cubs…) the system was over-sensitive and tolerated 'false positives' (leading to people attending to unrelated babes in need), and even got triggered by injured or starving adults – which it transpired increased fitness for the community, so was selected for…
It can be much easier to invent feasible-sounding evolutionary 'just-so stories' than rigorously testing them!
Scientist reveals what the earth has been trying to do
Keith S. Taber
Seismology – the study of the earth letting off steam? (Image by ELG21 from Pixabay)
"the earth has one objective, it has had one objective for four and half billion years, and that's…"
In our time
'In Our Time' is an often fascinating radio programme (and podcast) where Melvyn Bragg gets three scholars from a field to explain some topic to a general audience.
Imagine young Melvyn interrupting a physics teacher's careful exposition of why pV = 1/3nmc2 by asking how the gas molecules came to be moving in the first place.
I am not sure if the reason that I sometimes find the science episodes seem a little less erudite than those in the the other categories is:
a) Melvyn is more of an arts person, so operates at a different level in different topics;
b) I am more of a science person, so more likely to be impressed by learning new things in non-science topics; and to spot simplifications, over-generalisations, and so forth, in science topics.
c) A focus in recent years on the importance of the public understanding of science and science communication means that scientists may (often, not always) be better prepared and skilled at pitching difficult topics for a general audience.
d) Topics from subjects like history and literature are easier to talk about to a general audience than many science topics which are often highly conceptual and technical.
Anyway, today I did learn something from the episode on seismology ("Melvyn Bragg and guests discuss how the study of earthquakes helps reveal Earth's secrets [sic]"). I was told what the earth had been up to for the last four and half billion years…
Seismology: Where does this energy come from?
Quite early in the discussion Melvyn (sorry, The Lord Bragg CH – but he is so familiar from his broadcasts over the years that he seems like an old friend) interjected when Dr James Hammond (Reader in Geophysics at Birkbeck, University of London) was talking about forces involved in plate tectonics to ask "Where does this energy come from?". To this, Dr Hammond replied,
"The whole thing that drives the whole caboose?
It comes from plate tectonics. So, essentially the earth has one objective, it has had one objective for four and half billion years, and that's to cool down. We're [on] a big lump of rock floating in space, and it's got all this primordial energy, so we are going right back here, there's all this primordial energy from the the material coming together, and it's trying to cool down."
Dr James Hammond talking on 'In Our Time' 1
My immediate response, was that this was teleology – seeing purpose in nature. But actually, this might be better described as anthropomorphism. This explanation presents the earth as being the kind of agent that has an objective, and which can act in the world to work towards goals. That is, like a human:
Of course, in scientific terms, the earth has no such objective, and it is not trying to do anything as it is inanimate. Basic thermodynamics suggests that an object (e.g., the earth) that is hotter than its surroundings will cool down as it will radiate heat faster than it absorbs it. 2 (Of course, the sun is hotter than the earth – but that's a rather minority component of the earth's surroundings, even if in some ways a very significant one.) Hot objects tend to cool down, unless they have an active mechanism to maintain their temperature above their ambient backgrounds (such as 'warm-blooded' creatures). 3
So, in scientific terms, this explanation might be seen as flawed – indeed as reflecting an alternative conception of similar kind as when students explain evolutionary adaptations in terms of organisms trying to meet some need (e.g., The brain thinks: grow more fur), or explain chemical processes in terms of atoms seeking to meet a need by filling their electron shells (e.g., Chlorine atoms share electrons to fill in their shells).
Does Dr Hammond really believe this account?
Does Dr Hammond really think the earth has an objective that it actively seeks to meet? I very much doubt it. This was clearly rhetorical language adopting tropes seen as appropriate to meet the needs of the context (a general audience, a radio programme with no visuals to support explanations). In particular, he was in full flow when he was suddenly interrupted by Melvin, a bit like the annoying child who interrupts the teacher's carefully prepared presentation by asking 'but why's that?' about something it had been assumed all present would take for granted.
Imagine the biology teacher trying to discuss cellular metabolism when young Melvin asks 'but where did the sugar come from?'; or the chemistry teacher discussing the mechanism of a substitution reaction when young Melvin asks why we are assuming tetrahedral geometry around the carbon centre of interest; or young Melvyn interrupting a physics teacher's careful exposition of why pV = 1/3nmc2 by asking how the gas molecules came to be moving in the first place.
Of course, part of Melvin's job in chairing the programme IS to act as the child who does not understand something being taken for granted and not explained, so vicariously supporting the listener without specialist background in that week's topic.
Effective communication versus accurate communication?
Science teachers and communicators have to sometimes use ploys to 'make the unfamiliar familiar'. One common ploy is to employ an anthropomorphic narrative as people readily relate to the human experience of having goals and acting to meet needs and desires. Locating difficult ideas within such a 'story' framework is known to often make such ideas more accessible. Does this gain balance the potential to mislead people into thinking they have been given a scientific account? In general, such ploys are perhaps best used only as introductions to a difficult topic, introductions which are then quickly followed up by more technical accounts that better match the scientific narrative (Taber & Watts, 2000).
Clearly, that is more feasible when the teacher or communicator has the opportunity for a more extensive engagement with an audience, so that understanding can be built up and developed over time. I imagine Dr Hammond was briefed that he had just a few minutes to get across his specific points in this phase of the programme, only to then find he was interrupted and asked to address additional background material.
As a scientist, the notion of the earth spending billions of years trying to cool down grates as it reflects pre-scientific thinking about nature and acts as a pseudo-explanation (something which has the form of an explanation, but little substance).
As cooling is a very familiar everyday phenomena, I wondered if a basic response that would avoid anthropomorphism might have served, e.g.,
When the earth formed, it was very much hotter than today, and, as it was hotter than its surroundings, it has been slowly cooling ever since by radiating energy into space. Material inside the earth may be hot enough to be liquid, or – where solid – be plastic enough to be deformed. The surface is now much cooler than it was, but inside the earth it is still very hot, and radioactive processes continue to heat materials inside the earth. We can understand seismic events as driven by the ways heat is being transferred from deep inside the earth.
However, just because I am a scientist, I am also less well-placed to know how effective this might have been for listeners without a strong science background – who may well have warmed [sic] to the earth striving to cool.
Dr Hammond had to react instantly (like a school teacher often has to) and make a quick call based on his best understanding of the likely audience. That is one of the difference between teaching (or being interviewed by Melvin) and simply giving a prepared lecture.
1 Speech often naturally has repetitions, and markers of emphasis, and hesitations that seem perfectly natural when heard, but which do not match written language conventions. I have slightly tidied what I transcribed from:
"The whole thing that drives the whole caboose? It comes from plate tectonics, right. So, essentially the earth, right, has one objective, it has had one objective for four and half billion years, and that's to cool down. Right, we're a big lump of rock floating in space, and it's got all this primordial energy, so we are going right back here, there's all this primordial energy from, from the the material coming together,4 and it's trying to cool down."
2 In simple terms, the hotter an object is, the greater the rate at which it radiates.
The hotter the environment is, the more intense the radiation incident on the object and the more energy it will absorb.
Ultimately, in an undisturbed, closed system everything will reach thermal equilibrium (the same temperature). Our object still radiates energy, but at the same rate as it absorbs it from the environment so there is no net heat flow.
3 Historically, the earth's cooling was an issue of some scientific controversy, after Lord Kelvin (William Thomson) calculated that if the earth was cooling at the rate his models suggested for a body of its mass, then this was cooling much too rapid for the kind of timescales that were thought to be needed for life to have evolved on earth.
4 This is referring to the idea that the earth was formed by the coming together of material (e.g., space debris from a supernova) by its mutual gravitational attraction. Before this happens the material can be considered to be in a state of high gravitational potential energy. As the material is accelerated together it acquires kinetic energy (as the potential energy reduces), and then when the material collides inelastically it forms a large mass of material with high internal energy (relating to the kinetic and potential energy of the molecules and ions at the submicroscopic level) reflected in a high temperature.
Anthropomorphic language refers to non-human entities as if they have human experiences, perceptions, and motivations. Both non-living things and non-human organisms may be subjects of anthropomorphism. Anthropomorphism may be used deliberately as a kind of metaphorical language that will help the audience appreciate what is being described because of its similarly to some familiar human experience. In science teaching, and in public communication of science, anthropomorphic language may often be used in this way, giving technical accounts the flavour of a persuasive narrative that people will readily engage with. Anthropomorphism may therefore be useful in 'making the unfamiliar familiar', but sometimes the metaphorical nature of the language may not be recognised, and the listener/reader may think that the anthropomorphic description is meant to be taken at face value. This 'strong anthropomorphism' may be a source of alternative conceptions ('misconceptions') of science.
The first example was from the lead story about 'long COVID'.
Prof. Onur Boyman, Director of the Department of Immunology at the University Hospital, Zurich, was interviewed after his group published a paper suggesting that blood tests may help identify people especially susceptible to developing post-acute coronavirus disease 2019 (COVID-19) syndrome (PACS) – which has become colloquially known as 'long COVID'.
"We found distinct patterns of total immunoglobulin (Ig) levels in patients with COVID-19 and integrated these in a clinical prediction score, which allowed early identification of both outpatients and hospitalized individuals with COVID-19 that were at high risk for PACS ['long COVID']."
Cervia, Zurbuchen, Taeschler, et al., 2022, p.2
The study reported average patterns of immunoglobulins found in those diagnosed with COVID-19 (due to SARS-CoV-2 infection), and those later diagnosed with PACS. The levels of different types of immunoglobulins (designated as IgM, etc.) were measured,
Differentiating mild versus severe COVID-19, IgM was lower in severe compared to mild COVID-19 patients and healthy controls, both at primary infection and 6-month follow-up… IgG3 was higher in both mild and severe COVID-19 cases, compared to healthy controls …In individuals developing PACS, we detected decreased IgM, both at primary infection and 6-month follow-up… IgG3 tended to be lower in patients with PACS…which was contrary to the increased IgG3 concentrations in both mild and severe COVID-19 cases…
Cervia, Zurbuchen, Taeschler, et al., 2022, p.3
Viruses in a defensive mode
In the interview, Professor Boyman discussed how features of the immune system, and in particular immunoglobulins, were involved in responses to infection, and made the comment:
"IgG3…is smaller than IgM and therefore it is able to go into many more tissues. It is able to cross certain tissue barriers and go into those sites where viruses might actually try to go to and hide"
Prof. Onur Boyman interviewed on 'BBC Inside Science'
This is anthropomorphic as it refers to viruses trying to hide from the immune components. Of course, viruses are not sentient, so they do not try to do anything: they have no intentions. Although viruses might well pass across tissue barriers and move into tissues where they are less likely to come into contact with immunoglobulins, 'hiding' suggests a deliberate behaviour – which is not the case.
Professor Boyman is clearly aware of that, and either deliberately or otherwise was speaking metaphorically. Scientifically literate people would not be misled by this as they would know viruses are not conscious agents. However, learners are not always clear about this.
The bacteria, however, are going on the offensive
The other point I spotted was later in the same programme when the presenter, Gaia Vince, introduced an item about antibiotic resistance:
"Back in my grandparent's time, the world was a much more dangerous place with killer microbes lurking everywhere. People regularly died from toothache, in childbirth, or just a simple scratch that got infected. But at the end of the second world war, doctors had a new miracle [sic] drug called penicillin. Antibiotics have proved a game changer, taking the deadly fear away from common infections. But the microbes did not just accept defeat, they have been mounting their resistance and they are making a comeback."
Gaia Vince presenting 'Inside Science'
Antibiotics are generally ineffective against viruses, but have proved very effective treatments for many bacterial infections, including those that can be fatal when untreated. The functioning of antibiotics can be explained by science in purely natural terms, so the label of 'miracle drugs' is a rhetorical flourish: their effect must have seemed like a miracle when they first came into use, so this can also be seen as metaphoric language.
Bacteria regrouping for a renewed offensive? (Image by WikiImages from Pixabay )
However, again the framing is anthropomorphic. The suggestion that microbes could 'accept defeat' implies they are the kind of entities able to reflect on and come to terms with a situation – which of course they are not. The phrase 'mounting resistance' also has overtones of deliberate action – but again is clearly meant metaphorically.
Again, there is nothing wrong with these kinds of poetic flourishes in presenting science. Most listeners would have heard "microbes did not just accept defeat, they have been mounting their resistance and they are making a comeback" and would have spontaneously understood the metaphoric use of language without suspecting any intention to suggest microbes actually behave deliberately. Such language supports the non-specialist listener in accessing a technical science story.
Some younger listeners, however, may not have a well-established framework for thinking about the nature of an organism that is able to reflect on its situation and actively plan deliberate behaviours. After all, a good deal of children's literature relies on accepting that various organisms, indeed non-living entities such as trains, do have human feelings, motives and behavioural repertoires. (Learners may for example think that evolutionary adaptations, such as having more fur in a cold climate, are mediated by conscious deliberation.) Popular science media does a good job of engaging and enthusing a broad audience in science, but with the caveat that accessible accounts may be open to misinterpretation.
Work cited:
Cervia, C., Zurbuchen, Y., Taeschler, P. et al.(2022) Immunoglobulin signature predicts risk of post-acute COVID-19 syndrome. Nature Communications, 13, 446. https://doi.org/10.1038/s41467-021-27797-1
Is it poor scientific practice to explain away results we would not expect?
Keith S. Taber
how convinced would be be by a student who found an increase in mass after burning some magnesium and argued that this showed that combustion was a process of a substance consuming oxygen as a kind of food
I came across an interesting account of an experiment which seemed to support a hypothesis, but where the results were then explained away to reject the hypothesis.
An experiment to test whether a lodestone buried in iron filings will get heavier
Experimental results always need interpretation
That might seem somewhat dubious scientific practice, but one of the things that becomes clear when science is studied in any depth is that individual experiments seldom directly decide scientific questions. Not only is the common notion that a positive result proves a hypothesis correct over-simplistic, but it is also seldom the case that a single negative result can be assumed to be sufficient to reject a hypothesis. 1
Given that, the reason I thought this report was interesting is that it was published some time ago, indeed in 1600. It also put me in mind of a practical commonly undertaken in school science to demonstrate that combustion involves a substance combining with oxygen. In that practical activity (commonly mislabelled as an 'experiment' 2), magnesium metal (for example) is heated inside a ceramic crucible until it has reacted, and by careful weighing it is found (or perhaps I should say, it should be found, as it can be a challenging practical for the inexperienced) that the material after combustion weighs more than before – as the magnesium has reacted with a substance from the air (oxygen).3 This is said to give support to the oxygen theory of combustion, and to be contrary to the earlier phlogiston theory which considered flammable materials to contain a substance called phlogiston which was released during combustion (such that what remains is of less mass than before).
Testing whether lodestones eat iron
The historical experiment that put me in mind of this involved burying a type of stone known as a lodestone in iron filings. The stone and filings were carefully weighed before burial and then again some months later after being separated. The hypothesis being tested was that the weight of the lodestone would increase, and there would be a corresponding decrease in the mass of the weight of the iron filings. Apparently at the end of the experiment the measurements, strictly at least, suggested that this was what had occurred. Yet, despite this, the author presenting the account dismissed the result – arguing that it was more likely the finding was an artifact of the experimental procedure either not being sensitive enough, or not having been carried out carefully enough.
Explaining away results – in science and in school laboratories
That might seem somewhat against the spirit of science – I wonder if readers of this posting feel that is a valid move to make: to dismiss the results, as if scientists should be fee to pick and chose which results they wish to to take notice of?
But I imagine the parallel situation has occurred any number of times in science classrooms, for example where the teacher responds to students' practical demonstrations that what is left after burning magnesium has less mass than the magnesium had before. Rather than seeing this as a refutation of the oxygen hypothesis (actually now, of course, canonical theory) – and possible support for the notion that phlogiston had been released – the teacher likely explains this away as either a measurement error or, more likely, a failure to retain all of the magnesia [magnesium oxide] in the crucible for the 'after' measurement.
Hungry magnets
The historical example is discussed in William Gilbert's book about magnetism, usually known in English as 'On the magnet'. 4 This is sometimes considered the first science book, and consists of both a kind of 'literature review' of the topic, as well as a detailed report of a great many observations and demonstrations that (Gilbert claims) were original and made by Gilbert himself. There were no professional scientists in 1600, and Gilbert was a physician, a medical practitioner, but he produced a detailed and thoughtful account of his research into magnets and magnetism.
Gilbert's book is fascinating to a modern reader for its mixture of detailed accounts that stand today (and many of which the reader could quite easily repeat) alongside some quite bizarre ideas; and as an early example of science writing that mixes technical accounts with language that sometimes seems quite unscientific by today's norms – including (as well as a good deal of personification and anthropomorphism) some very unprofessional remarks about some other scholars he considers mistaken. Gilbert certainly has little time for philosophers ('philosophizers') who set out theories about natural phenomena without ever undertaking any observations or tests for themselves.
Lodestones
Magnetism has been known since antiquity. In particular, some samples of rock (usually samples of magnetite, now recognised as Fe3O4) were found to attract both each other and samples of iron, and could be used as a compass as they aligned, more or less, North-South when suspended, or when floated in water (in a makeshift 'boat'). Samples of this material, these naturally occurring magnets, were known as lodestones.
Yet the nature of magnetism, seemingly an occult power that allowed a stone to attract an iron nail, or the earth to turn a compass needle, without touching it, remained a mystery. Some of the ideas that had been suggested may seem a little odd today.
Keepers as nutrients?
So, for example, it is common practice to store magnets with 'keepers'. A horseshoe magnet usually has a steel rod placed across its ends, and bar magnets are usually stored in pairs with steel bars making a 'circuit' by connecting between the N of one magnet with the S of the other. But why?
One idea, that Gilbert dismisses is that the magnet (lodestone) in effect needs a food source to keep up its strength,
"The loadstone is laid up in iron filings, not that iron is its food; as though loadstone were alive and needed feeding, as Cardan philosophizes; nor yet that so it is delivered from the inclemency of the weather (for which cause it as well as iron is laid up in bran by Scaliger; mistakenly, however, for they are not preserved well in this way, and keep for years their own fixed forms): nor yet, since they remain perfect by the mutual action of their powders, do their extremities waste away, but are cherished & preserved, like by like."
Gilbert, 1600 – Book 1, Chapter 16.
Girolamo Cardano was an Italian who had written about the difference between amber (which can attract small objects due to static electrical charges) and lodestones, something that Gilbert built upon. However, Gilbert was happy to point out when he thought 'Cardan' was mistaken.
An experiment to see if iron filings will feed a magnet
Gilbert reports an experiment carried out by Giambattista della Porta. Porta's own account is that:
"Alexander Aphrodiseus in the beginning of his Problems, enquires wherefore the Loadstone onely draws Iron, and is fed or helped by the fillings of Iron; and the more it is fed, the better it will be: and therefore it is confirmed by Iron. But when I would try that, I took a Loadstone of a certain weight, and I buried it in a heap of Iron-filings, that I knew what they weighed; and when I had left it there many months, I found my stone to be heavier, and the Iron-filings lighter: but the difference was so small, that in one pound I could finde no sensible declination; the stone being great, and the filings many: so that I am doubtful of the truth."
Porta, 1658: Book 7, Chapter 50
Gilbert reports Porta's experiment in his own treatise, but adds potential explanations of why the iron filings had slightly lost weight (it is very easy to lose some of the material during handling), and why the magnet might be slightly heavier (it could have become coated in some material during its time buried),
"Whatever things, whether animals or plants, are endowed with life need some sort of nourishment, by which their strength not only persists but grows firmer and more vigorous. But iron is not, as it seemed to Cardan and to Alexander Aphrodiseus, attracted by the loadstone in order that it may feed on shreds of it, nor does the loadstone take up vigour from iron filings as if by a repast on victuals [i.e., a meal of food]. Since Porta had doubts on this and resolved to test it, he took a loadstone of ascertained weight, and buried it in iron filings of not unknown weight; and when he had left it there for many months, he found the stone of greater weight, the filings of less. But the difference was so slender that he was even then doubtful as to the truth. What was done by him does not convict the stone of voracity [greediness, great hunger], nor does it show any nutrition; for minute portions of the filings are easily scattered in handling. So also a very fine dust is insensibly born on a loadstone in some very slight quantity, by which something might have been added to the weight of the loadstone but which is only a surface accretion and might even be wiped off with no great difficulty."
Gilbert, 1600 – Book 2, Chapter 25.
Animistic thinking
To a modern reader, the idea that a lodestone might keep up its strength by eating iron filings seems very fanciful – and hardly scientific. To refer to the stone feeding, taking food, or being hungry, is animistic – treating the stone as though it is a living creature. We might wonder if this language is just being used metaphorically, as it seems unlikely that intelligent scholars of the 16th Century could actually suspect a stone might be alive. Yet, as Gilbert points out, there was a long tradition of considering that the lodestone, being able to bring about movement, had a soul, and Gilbert himself seemed to feel this was not so 'absurd'.
A reasonable interpretation?
We should always be aware of the magnitude of likely errors in our measurements, and not too easily accept results at the margins of what can be measured. Gilbert's suggestions for why the test of whether mass would be transferred from the iron to the magnet might have given flawed positive results seem convincing. It would be easy to lose some of the filings in the experiment: especially if the "heap of Iron-filings" was left for several months without any containment! And the lodestone could indeed easily acquire some extraneous material that needed to be cleaned off to ensure a valid weighing. As the lodestone attracts iron, all of the filings would need to be carefully cleaned from it (and returned to the 'heap' before the re-weighing).
But, I could not help but wonder if, in part at least, I found Gilbert's explaining away of the results as reasonable, simply because I found the premise of the iron acting as a kind of food as ridiculous. We should bear in mind that although the predicted change in mass was motivated by a notion of the magnet needing nutrition, that might not be the only scenario which might give rise to the same prediction. 1 After all, how convinced would be be by a student who
suggested combustion was a process of a substance consuming oxygen as a kind of food, and
therefore predicted that magnesium would be found to have got heavier after a good meal, and
subsequently found an increase in mass after burning some magnesium, and
argued that this gave strong support for the oxygen-as-food principle?
Coda
It is rather difficult for us today to really judge how language was used centuries ago. Do these natural philosophers talking of magnets eating iron mean this literally, or is it just figurative – intended as a metaphor that readers would understand suggested that there was a process somewhat akin to when a living being eats? 5 Some of them seemed quite serious about assigning souls to entities we today would conspire obviously inanimate. But we should be careful of assuming apparently incredible language was meant, or understood, literally.
In the same week as I was drafting this posting I read an article in Chemistry World about how the heavier elements are produced, which quoted Professor Brian Metzer, physicist at Columbia University,
"What makes the gamma-ray burst in both of these cases [merging neutron stars and the collapse of large rapidly rotating stars] is feeding a newly-formed black hole matter at an extremely high rate…The process that gives rise to the production of this neutron-rich material is actually outflows from the disc that's feeding the black hole."
Brian Metzer quoted in Wogan, 2022
If we would be confident that Professor Metzer meant 'feeding a black hole' to be understood figuratively, we should be careful to reserve judgement on how the feeding of lodestones was understood when Porta and Gilbert were writing.
Sources cited:
Gilbert, W. (1600/1900). On the Magnet, Magnetick Bodies also, and on the great magnet of the earth; a new physiology, demonstrated by many arguments & experiments (S. P. Thompson, Trans. Project Gutenberg ed.). [Available as a free e-book at https://www.gutenberg.org/files/33810/33810-h/33810-h.htm]
Wogan, T. (2022, 5th Janaury 2022). How elements are made beyond the stars. Chemistry World, 19, 28-31.
Notes:
1 Strictly scientific tests never 'prove' or 'disprove' anything.
The notion of 'proof' is fine in the context of purely theoretical disciplines such as in mathematics or logic, but not in science which tests ideas empirically. Experimental results always underdetermine theories (that is, it is always possible to think up other theories which also fit the results, so a result never 'proves' anything). Apparently negative results do not refute ('disprove') a theory either, as any experimental test of a hypothesis also depends upon other factors (Has the researcher been sloppy? Is the measuring instrument valid – and correctly calibrated? Are any simplifying assumptions reasonable in the context…). So experimental results offer support for, or bring into question, specific theoretical ideas, without ever being definitive.
2 An experiment is undertaken to test a hypothesis. Commonly in school practical work 'experiments' are carried out to demonstrate an accepted principle, such that it is already determined what the outcome 'should' be – students may have already been told the expected outcome, it appears i n their textbooks, and the title of the activity may be suggestive ('to show that mass increases on combustion'). Only if there is a genuine uncertainty about the outcome should the activity be labelled an experiment – e.g., it has been suggested that combustion is like the fuel eating oxygen, in which case things should be heavier after burning – so let's weigh some magnesium, burn it, and then re-weight what we have left (dephlogisticated metal?; compound of metal with oxygen?; well-fed metal?)
3 Mass and weight are not the same thing. However, in practice, measurements of weight made in the laboratory can be assumed as proxy measurements for mass.
4 As was the norm in European scholarship at that time, Gilbert wrote his treatise in Latin – allowing scholars in different countries to read and understand each other's work. The quotations given here are from the 1900 translation into English by S.P. Thompson.
5 Such metaphors can act as communication tools in 'making the unfamiliar familiar' and as thinking tools to help someone pose questions (hypotheses?) for enquiry. There is always a danger, however, that once such figures of speech are introduced they can channel thinking, and by providing a way of talking about and thinking about some phenomena they can act as obstacles to delving deeper in their nature (Taber & Watts, 1996).
Anthropomorphism is the name given treating non-human entities as if they were human actors. An example of anthropomorphic language would be "the atom wants to donate an electron so that it can get a full outer shell" (see for example: 'A sodium atom wants to donate its electron to another atom'). In an example such as that, an event that would be explained in terms of concepts such as force and energy in a scientific account (the ionisation of an atom) is instead described as if the atom is a conscious agent that is aware of its status, has preferences, and acts to bring about desired ends.
Of course, an atom is not a complex enough entity to have mental experience that allows it to act deliberately in the world, so why might someone use such language?
Perhaps, if the speaker was a young learner, because they have not been taught the science.
Perhaps a non-scientist might use such language because they can only make sense of the abstract event in more familiar terms.
But what if the speaker was a scientist – a science teacher or a research scientist?
When fellow professionals (e.g., scientists) talk to each other they may often use a kind of shorthand that is not meant to be taken literally (e.g., 'the molecule wants to be in this configuration') simply because it can shorten and simplify more technical explanations that both parties understand. But when a teacher is talking to learners or a scientist is trying to explain their ideas to the general public, something else may be going on.
Anthropomorphism in science communication and education
In science teaching or science communication (scientists communicating science to the public) there is often a need to present abstract or complex ideas in ways that are accessible to the audience. At one level, teaching is about shifting what is to be taught from being unfamiliar to learners to being familiar, and one way to 'make the unfamiliar familiar' is to show it is in some sense like something already familiar.
Therefore there is much use of simile and analogy, and of telling stories that locate the focal material to be learned within a familiar narrative. Anthropomorphism is often used in this way. Inanimate objects may be said to want or need or try (etc.) as the human audience can relate to what it is to want or need or try.
Such techniques can be very useful to introduce novel ideas or phenomena in ways that are accessible and/or memorable ('weak anthropomorphism'). However, sometimes the person receiving these accounts may not appreciate their figurative nature as pedagogic / communicative aids, and may mistake what is meant to be no more than a starting point, a way into a new topic or idea, as being the scientific account itself. That is, these familiarisation techniques can work so well that the listener (or reader) may feel satisfied with them as explanatory accounts ('strong anthropomorphism').
Evolution – it's just natural (selection)
A particular issue arises with evolution, when often science only has hypothetical or incomplete accounts of how and why specific features or traits have been selected for in evolution. It is common for evolution to be misunderstood teleologically – that is, as if evolution was purposeful and nature has specific end-points in mind.
The scientific account of evolution is natural selection, where none of genes, individual specimens, populations or species are considered to be deliberately driving evolution in particular directions (present company excepted perhaps – as humans are aware of evolutionary processes, and may be making some decisions with a view to the long-term future). 1
Yet describing evolutionary change in accord with the scientific account tends to need complex and convoluted language (Taber, 2017). Teleological and anthropomorphic shorthand is easier to comprehend – even if it puts a burden on the communicatee to translate the narrative into a more technical account.
What the virus tries to do
The first example from the recent Science in Action episode related to the COVID pandemic, and the omicron variant of the SARS-CoV-2 virus. This was the lead story on the broadcast/podcast, in particular how the travel ban imposed on Southern Africa (a case of putting the lid on the Petri dish after the variant had bolted?) was disrupting supplies of materials needed to address the pandemic in the countries concerned.
This was followed by a related item:
"Omicron contains many more mutations than previous variants. However scientists have produced models in the past which can help us understand what these mutations do. Rockefeller University virologist Theodora Hatziioannou produced one very similar to Omicron and she tells us why the similarities are cause for concern."
"When you give the virus the opportunity to infect so many people, then of course it is going to try not only every possible mutation, but every possible combination of mutations, until it finds one that really helps it overcome our defences."
Dr Theodora Hatziioannou interviewed on Science in Action
Dr Theodora Hatziioannou Research Associate Professor Laboratory of Retrovirology The Rockefeller University
I am pretty sure that Dr Hatziioannou does not actually think that 'the virus' (which of course is composed of myriad discrete virus particles) is trying out different mutations intending to stop once it finds one which will overcome human defences. I would also be fairly confident that in making this claim she was not intending her listeners to understand that the virus had a deliberate strategy and was systematically working its way through a plan of action. A scientifically literature person should readily interpret the comments in a natural selection framework (e.g., 'random' variation, fitness, differential reproduction). In a sense, Dr Hatziioannou's comments may be seen as an anthropomorphic analogy – presenting the 'behaviour' of the virus (collectively) by analogy with human behavior.
Yet, as a science educator, such comments attract my attention as I am well aware that school age learners and some adult non-scientists may well understand evolution to work this way. Alternative conceptions of natural selection are very common. Even when students have been taught about natural selection they may misunderstand the process as Lamarckian (the inheritance of acquired characteristics – see for example 'The brain thinks: grow more fur'). So, I wonder how different members of the public hearing this interview will understand Dr Hatziioannou's analogy.
Even before COVID-19 came along, there was a tendency for scientists to describe viruses in such terms as as 'smart', 'clever' and 'sneaky' (e.g., 'So who's not a clever little virus then?'). The COVID pandemic seems to have unleashed a (metaphorical) pandemic of public comments about what the virus wants, and what it tries to achieve, and so forth. When a research scientist talks this way, I am fairly sure it is intended as figurative language. I am much less sure when, for example, I hear a politician telling the public that the virus likes cold weather ('What COVID really likes').
Vulture bees have the guts for it
The other item that struck me concerned vulture bees.
"Laura Figueroa from University of Massachusetts in Amhert [sic] in the US, has been investigating bees' digestive systems. Though these are not conventional honey bees, they are Costa Rican vulture bees. They feed on rotting meat, but still produce honey."
Bees do not actually make reasoned choices about their diets (Original image by Oldiefan from Pixabay)
The background is that although bees are considered (so I learned) to have evolved from wasps, and to all have become vegetarians, there are a few groups of bees that have reverted to the more primitive habits of eating meat. To be fair to them, these bees are not cutting down the forests to set up pasture and manage livestock, but rather take advantage of the availability of dead animals in their environment as a source of protein.
These vulture bees (or carrion bees) are able to do this because their gut microbiomes consist of a mix of microbes that can support them in digesting meat, allowing them to be omnivores. This raises the usual kind of 'chicken and egg' question 1 thrown up by evolutionary developments: how did vegetarian bees manage to shift their diet: the more recently acquired microbes would not have been useful or well-resourced whilst the bees were still limiting themselves to a plant-based diet, but the vegetarian bees would not have been able to digest carrion before their microbiomes changed.
As part of the interview, Dr Figueroa explaied:
"These are more specialised bees that once they were vegetarian for a really long time and they actually decided to change their ways, there's all of this meat in the forest, why not take advantage? I find that super-fascinating as well, because how do these shifts happen?
Because the bees, really when we are thinking about them, they've got access to this incredible resource of all of the flowering plants that are all over the world, so then why switch? Why make this change?
Over evolutionary time there are these mutations, and, you know, maybe they'd have got an inkling for meat, it's hard to know how exactly that happened, but really because it is a constant resource in the forest, there's always, you know, this might sound a little morbid but there's always animals that are dying and there's always this turn over of nutrients that can happen, and so potentially this specialised group of bees realised that, and maybe there's enough competition on the flowers that they decided to switch. Or, they didn't decide, but it happened over evolutionary time.
Dr Laura Figueroa interviewed on Science in Action
Dr Figueroa does not know exactly how this happened – more research is needed. I am sure Dr Figueroa does not think the bees decided to change their ways in the way that a person might decide to change their ways – perhaps deciding to get more exercise and go to bed earlier for the sake of their health. I am also sure Dr Figueroa does not think the bees realised that there was so much competition feeding on the flowers that it might be in their interests to consider a change of diet, in the way that a person might decide to change strategy based on an evaluation of the competition. These are anthropomorphic figures of speech.
Dr Laura Figueroa, NSF Postdoctoral Research Fellow in Biology Department of Entomology, Cornell University / University of Massachusetts in Amherst
As she said "they didn't decide, but it happened over evolutionary time". Yet it seems so natural to use that kind of language, that is to frame the account in a narrative that makes sense in terms of how people experience their lives.
Again, the scientifically literate should appreciate the figurative use of language for what it is, and it is difficult to offer an accessible account without presenting evolutionary change as purposive and the result of deliberation and strategy. Yet, I cannot help wondering if this kind of language may reinforce some listeners' alternative conceptions about how natural selection works.
Work cited:
Dawkins, R. (1976/1989). The Selfish Gene (New ed.). Oxford: Oxford University Press.
1 The 'selfish' gene made famous by Dawkins (1976/1989) is not really selfish in the sense a person might be – rather this was an analogy which helped shift attention from changes at the individual or species level when trying to understand how evolution occurs, to changes in the level of distinct genes. If a mutation in a specific gene leads to a change in the carrying organism that (in turn) leads to that specimen having greater fitness then the gene itself has an increased chance of being replicated. So, from the perspective of focusing on the genes, the change at the species level can be seen as a side effect of the 'evolution' of the gene. The gene may be said to be (metaphorically) selfish because it does not change for the benefit of the organism, but to increase its own chances of being replicated. Of course, that is also an anthropomorphic narrative – actually the gene does not deliberately mutate, has no purpose, has no notion of replication, indeed, does not even 'know' it is a gene, and so forth.
2 Such either/or questions can be understood as posing false dichotomies (here, either the bees completely changed their diets before their microbiomes or their microbiomes changed dramatically before their diets shifted) when what often seems most likely is that change has been slow and gradual.
