NASA's James Webb Space Telescope is now operational, and offering new images of 'deep space'. This has led to claims of finding images of objects from further away in the Universe, and so from further back in time, than previously seen. This should support a lot of new scientific work and will surely lead to some very interesting findings. Indeed, it seems to have had an almost immediate impact.
Maisie's galaxy
One of these new images is of an object known as:
CEERSJ141946.35-525632.8
or less officially (but more memorably) as
Masie's galaxy.
A red smudge on one of the new images has been provisionally identified as evidence of a galaxy as it was less than 300 000 000 years after the conjectured 'big bang' event understood as the origin of the universe. The galaxy is so far away that its light has taken since then to reach us.
Three hundred million years seems a very long time in everyday terms, but it a small fraction of the current age of the universe, believed to be around fourteen billion years. 1
300 000 000 years
≪ 14 000 000 000 years
The age estimate is based on the colour of the object, reflecting its 'redshift':
"Scientists with the CEERS Collaboration have identified an object–dubbed Maisie's galaxy in honor of project head Steven Finkelstein's daughter–that may be one of the earliest galaxies ever observed. If its estimated redshift of 14 is confirmed with future observations, that would mean we're seeing it as it was just 290 million years after the Big Bang."
This finding is important in understanding the evolution of the universe – for example, observing the earliest galaxies puts a limit on how long the universe existed before star formation started. (Although the episode was called 'The first galaxies at the universe's dawn' Masie's galaxy is thought to contain heavier elements that were produced in even earlier stars.)
Uncertainty in science (and certainty in reporting science)
So, the claim is provisional. It is an estimate awaiting confirmation.
Strictly, science is concerned with provisional knowledge claims. This is not simply because scientists can make mistakes. All measurements are subject to limits in precision (measurement 'errors'). More fundamentally, all measurements depend on a theory of the instrumentation used, and theoretical knowledge is always open to being revisited on the basis of new ways of understanding.
We may not expect the theory behind the metre rule to change any time soon (although even there, our understanding shifted somewhat with Einstein's theories) but many scientific observations depend on highly complex apparatus, both for data collection and analysis. Despite this, science is often represented in the media, both by commentators and sometimes scientists themselves, as if it produced absolute certainty.
"We can look deep into out past by taking these deep images, and we can find the sort of faintest red smudges and that tells us that they are extremely far away, and from exactly how red they are we can estimate that distance."
So, the figure of 290 000 000 years after the big bang is an estimate. Fair enough, but what 'caught my ear', so to speak, was the contrast between the acknowledged uncertainty of the current estimate, and the claimed possibility of moving from this to absolute knowledge,
"If this distance we have measured for Masie's galaxy, of a red shift of 14, holds true, and I can't stress enough that we need spectroscopic confirmation to precisely measure that distance. [*] Where you take a telescope, could be James Webb, could be a different telescope, you observe it [the galaxy] and you split the light into its component colours, and you can actually precisely measure – measure the red shift, measure the distance – a hundred percent conclusively."
Associate Professor Steve Finke [* To my ear, there might well be an edit at this point – the quote is based on what was broadcast which might omit or re-sequence parts of the interview.]
Spectroscopic analysis allows us to compare the pattern of redshifted spectral lines due to the presence of elements absorbing or emitting radiation, with the position of those lines as they are found without any shift. Each element has its own pattern of lines – providing a metaphorical fingerprint. A redshift (or blueshift) moves these lines to different parts of the spectrum, but does not change their collective profile as all the lines are moved to the same extent.
Spectral lines can be used like fingerprints to identify substances. (Image by No-longer-here from Pixabay)
Some of these lines are fine, allowing precise measurements of wavenumber/frequency, and there are enough of them to be able to make very confident assignments of the 'fingerprints', and use this to estimate the shift. We might extend our analogy to a fingerprint on a rubber balloon which had been stretched since a fingerprint was made. In absolute terms, the print would no longer (or 'no wider' for that matter) fit the finger that made it, but the distortion is systematic allowing a match to be made – and the degree of stretching to be calculated.
If a pattern is distorted in a systematic way, we may still be able to match it to an undistorted version (Original images by Clker-Free-Vector-Images (balloon), OpenClipart-Vectors (print) and Alexander (notepad) from Pixabay)
Yet, even though this is a method that is considered well-understood, reliable, and potentially very accurate and precise 2, I am not sure you can "precisely measure, measure the redshift, measure the distance. A hundred percent conclusively". Science, at least as I understand it, always has to maintain some small level of humility.
Scientists may be able to confirm and hone the estimate of 290 000 000 years after the big bang for the age of Maisie's galaxy. Over time, further observations, new measurements, refinement in technique, or even theory, may lead to successive improvements in that age measurement and both greater accuracy and greater precision.2 But any claim of a conclusive measurement to a precision of 100% has a finality that sounds like something other than science to me.
Notes
1 Oddly, most webages I've seen that cite values for the age of the universe do not make it explicit whether these are American (109) or English (1012) billions! It seems to be assumed that, as with sulfur [i.e., sulphur], and perhaps soon aluminum and fosforus, we are all using American conventions.
2 Precision and accuracy are different. Consider an ammeter.
An ammeter (Image by Gerd Altmann from Pixabay)
Due to the method of reading a needle position against a scale there is a limit to precision (perhaps assumed to the nearest calibration, so to ±0.5 calibrations). This measurement error of ±0.5 units is, in effect, a limit in detail or resolution, but not an 'error' in the everyday sense of getting something wrong. However, if the meter had been miscalibrated, or over time has shifted from calibration, so the needle is misaligned (so perhaps the meter reads +0.15 A when it is not connected into a circuit) then that is inaccuracy. There is always some level of imprecision (some limit on how precise we can be), even when we have an accurate reading.
In science, a measurement normally offers a best estimate of a true value, with an error range acknowledging how far the real value might be from that best estimate. See the example below: Measurement B claims the most precision, but is actually inaccurate. Measurement A is the most accurate (but least precise).
If we imagine that a galaxy was being seen as it was
275 000 000 years after the big bang
and three measurements of its age were given as:
A: 280 000 000 ± 30 000 000 years after the big bang
(i.e., 250 000 000 – 310 000 000)
B: 290 000 000 ± 10 000 000 years after the big bang
(i.e., 280 000 000 – 300 000 000)
C: 260 000 000 ± 20 000 000 years after the big bang
(i.e., 240 000 000 – 280 000 000)
then measurement B is more precise (it narrows down the possible range the most) but is inaccurate (as the actual age falls outside the range of this measurement). Of course, unlike in such a hypothetical example, in a real case we would not know the actual age to allow us to decide which of the measurements is more accurate.
The brain's reward pathway is like a teeter-totter because…
Keith S. Taber
in your brain there is a teeter-totter like in a kids' playground…these neuroadaptation gremlins hopping on the pain side of the balance…the gremlins hop off …But if we …accumulate so many gremlins on the pain side of our balance …we've crossed over into the disease of addiction…we are craving because …it's the gremlins jumping up and down
Dr Anna Lembke talking on 'All in the mind'
Is there a see-saw in your brain? (Original images by Image by mohamed Hassan and OpenClipart-Vectors from Pixabay)
Dr Anna Lembke, Professor of Psychiatry at Stanford University explained how addiction relates to dopmaine and the brain's reward pathway with an analogy of a see-saw. She was talking to Sana Qadar for an episode of the the ABC programme 'All in the Mind' called 'How dopamine drives our addictions'.
Analogies are used in teaching and in science communication to help 'make the unfamiliar familiar', to show someone that something they do not (yet) know about is actually, in some sense at least, a bit like something they are already familiar with. In an analogy, there is a mapping between some aspect(s) of the structure of the target ideas and the structure of the familiar phenomenon or idea being offered as an analogue. Such teaching analogies can be useful to the extent that someone is indeed highly familiar with the 'analogue' (and more so than with the target knowledge being communicated); that there is a helpful mapping across between the analogue and the target; and that comparison is clearly explained (making clear which features of the analogue are relevant, and how).
During the programme the interviewer (Qadar) uses a metaphor for how addiction influences brain chemistry:
Sana Qadar: "The problem is when we are becoming addicted to something, our brain's ability to naturally produce dopamine gets fried."
Anna Lembke: "So essentially what happens in the brain as we tip toward the compulsive cycle of overconsumption or addiction is that we start to down-regulate our own dopamine production and dopamine transmission in order to compensate for the ways that we are bombarding our brain's reward pathway with too much dopamine through ingestion of these incredibly potent and rewarding substances and behaviours."
What does Sana Qadar mean by 'fried'? Presumably not destroyed, as the subsequent interview suggests that recovery is possible (see below) – although the brain's ability to naturally produce dopamine would surely not recover from actual frying. So, perhaps, fried means disturbed, or damaged? Given the following dialogue it might mean thrown out of balance.
Perhaps Qadar was thinking of the brain as circuitry as the term is commonly applied to damaged circuits (I think the term derives from damage caused by overheating, as can happen when there is a 'short' for example, which does stop the 'fried' components functioning permanently). So, perhaps for Qadar this is a dead metaphor – a term which started as a metaphor but which, with habitual use, has come to be treated as having literal meaning – at least in relation to electrical circuits and, by analogy, brain circuitry?
A fried brain? (Images by OpenClipart-Vectors and y Roger YI from Pixabay)
Balancing those gremlins
What I found especially interesting is the way Dr Lembke made extensive use of an analogy in her explanation, much in the way teacher might keep referring back to the same metaphor or analogy or model when introducing an abstract topic.
Sana Qadar tells listeners that "to explain how this process unfolds in the brain's reward pathway, Dr Lembke uses the analogy of a teeter-totter or seesaw":
"Because pleasure and pain are processed in the same part of the brain and work like opposite sides of the balance, it means for every pleasure there is a cost and that cost is pain.
So, if you imagine that in your brain there is a teeter-totter like in a kids' playground, that teeter-totter will tip to one side when we experience pleasure, and the opposite side when we experience pain.
But no sooner has that balance tipped to the side of pleasure, for example when I eat a piece of chocolate, then my brain will work very hard to restore a level balance or what neuroscientists call homeostasis. And it does that not just by bringing the balance level again but first by tipping it an equal and opposite amount to the to the side of pain, that is the after-effect, the come-down. I imagine that as these neuroadaptation gremlins hopping on the pain side of the balance to bring it level again.
Now, if we wait long enough, the gremlins hop off and homeostasis is restored as we go back to our baseline tonic level of dopamine firing. But if we continue to ingest addictive substances or behaviours over very long periods of time, we essentially accumulate so many gremlins on the pain side of our balance that we are in a chronic dopamine deficit state, and that is essentially where we get when we've crossed over into the disease of addiction.
Dr Anna Lembke talking on 'All in the mind'
As part of the programme of treatment Dr Lembke has developed for those suffering from additions she often recommends a period of complete abstinence – asking her clients to abstain for at least 30 days
Because 30 days is about the minimum amount of time it takes for the brain to restore baseline dopamine firing. Another way of saying this is 30 days is about the minimum amount of time it takes for the gremlins to hop off the pain side of the balance so that homeostasis or balance can be restored.
… I think in many people it is possible with abstinence to reset the reward pathway, the brain has an enormous amount of plasticity.
Dr Anna Lembke talking on 'All in the mind'
Abstinence is obviously not easy when the person is constantly faced with relevant triggers, as
"…what happens when we are triggered is that we release a little bit of dopamine in the reward pathway. … But if we wait long enough, those gremlins will hop off the pain side of the balance, and balance is restored….we are craving because we are in a dopamine deficit state, it's the gremlins jumping up and down on the pain side of the balance. But if we can just wait a few more moments, they will get off, homeostasis will be restored and that feeling will pass."
"…It's a fine line between pleasure and pain You've done it once you can do it again Whatever you've done don't try to explain It's a fine, fine line between pleasure and pain.."
From the lyrics of the song 'Pleasure and Pain' (covered by Manfred Mann's Earth Band), by Holly Knight & Michael Donald Chapman
It's a fine line between pleasure and pain
Sana Qadar suggests that certain kinds of pain can actually be good for us. From a biological perspective this is clearly so, as pain provides signals to motivate us to change our behaviour (move away from the fire, put down the very heavy object), but that is not what she is referring to. Rather, that "Dr Lembke says it has to do with the fact that pleasure and pain are processed in the same part of the brain":
Well, just like when we press on the pleasure side of the balance the gremlins hop on the pain side and ultimately shift our hedonic setpoint or our joy setpoint to the side of pain, it's also true that when we press on the pain side of the balance, so we intentionally invite psychologically or physically painful experiences into our lives, that those neuroadaptation gremlins will then hop on the pleasure side of the balance and we will start to up-regulate our own endogenous dopamine, not as the primary response to the stimulus but as the after-response
…I'm absolutely not talking about extreme forms of pain like cutting [which is] not a healthy way to get dopamine
…[For example] Michael was somebody who was addicted to cocaine and alcohol, and got into recovery and immediately experienced the dopamine deficit state, those gremlins on the pain side of the balance, he was anxious, he was irritable, and he also felt very numb, kind of an absence of emotions, which was really scary for him.
And he serendipitously discovered in early recovery that if he took a very cold shower, that created for him the same kinds of feelings, in a muted way, that he used to get from drugs, so he got into this practice of every morning taking a cold shower, and it worked great for him."
Dr Anna Lembke talking on 'All in the mind'
Gremlins, indeed?
Of course there is no see-saw in the brain, but a see-saw is a familiar everyday object that people understand can be balanced – or not. And that if more children (of similar size) load up one side than the other it will be out of balance – and it will only level up once the loads are balanced.
Strictly, there are some complications here with the analogue. If the children are at different distances from the fulcrum that will change their turning effect (so two children could balance one of similar mass according to where they are positioned). Similarly, when the moments are balanced the see-saw will not necessarily be level: as 'balance' means no overall turning effect. So, if the see-saw was already at an angle to the horizontal, loading it up in a balanced way should not shift it back to being level.
Perhaps there is something comparable in the reward system to whereabouts children sit on the see-saw – (perhaps some synapses are more sensitive to the effects of dopamine than others?), but this would be over-complicating an analogy that is intended to offer a link to a simple everyday phenomenon.
Are gremlins like children – do they come in different sizes? Perhaps it seems a little childish even to talk of such things in the brain. But there was once a strong (if discouraged these days 1) tradition of considering a homunculus, a little observer, inside the brain as if in a control room. Moreover, if the lauded physicist James Clerk Maxwell could invoke his famous demon to explain aspects of thermodynamics, we should not censure Lembke's metaphorical gremlins.
If this comparison was being used as a teaching analogy in a formal course, then we might want a more careful setting out of the positive and negative aspects of the analogy (those things that do, and do not, map across from the see-saw to the reward system). But Dr Lembke is not trying to teach her clients to pass tests about brain science, but rather give them a way of thinking about their problems that can help them plan and change behaviour – that is, a useful and straightforward model they can apply in overcoming their addictions.
Prof. Lembke was talking about a very important topic and here I have only abstracted particular comments to illustrate her use of the analogy. For a fuller account of the topic, and in particular Prof. Lembke's clinical work to help people struggling with addiction, please refer to the full interview.
Work cited:
Nguyen JD, Duong H. Neurosurgery, Sensory Homunculus. [Updated 2021 Jul 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549841/
Note
1 The term is still use, but in a somewhat different sense:
"in neuroanatomy, the cortical homunculus represents either the motor or the sensory distribution along the cerebral cortex of the brain. The motor homunculus is a topographic representation of the body parts and its correspondents along the precentral gyrus of the frontal lobe. While the sensory homunculus is a topographic representation of the body parts along the postcentral gyrus of the parietal lobe."
Nguyen and Duong, 2021
So, nowadays we each have two 'little men' in our brains.
"…I am older than I once was And younger than I'll be But that's not unusual No, it isn't strange After changes upon changes We are more or less the same After changes we are more or less the same…"
From the lyrics of 'The Boxer' (Simon and Garfunkel song) by Paul Simon
In a recent post I discussed the treatment of Newtonian forces in a book (Thomson, 2005) about the history of natural theology (a movement which sought to study the natural world as kind of religious observance – seeking to glorify God by the study of His works) and its relationship to the development of evolutionary theory.
The book was written by a prestigious scientist, who had held Professorships at both Yale in the US and at Oxford. Yet the book contained some erroneous physics – 'howlers' of the kind that are sometimes called 'schoolboy errors' (as presumably most schoolgirls would be careful not to make them?)
My point is not to imply that this is a poor read – the book has much to commend it, and I certainly thought it was worth my time. I found it an informative read, and I have no reason to assume that the author's scholarship in examining the historical sources was was not of the highest level – even if his understanding of some school physics seemed questionable. I think this highlights two features of science:
Science is so vast that research scientists setting out to write 'popular' science books for a general readership risk venturing into areas outside their specialist knowledge – areas where they may lack expertise 1
Some common alternative conceptions ('misconceptions') are so insidious that we confidently feel we understand the science we have been taught whilst continuing to operate with intuitions at odds with the science.
Out of specialism
In relation to the first point, I previously highlighted a reference to "Einstein's relativity theory" being part of quantum physics, and later in the book I found another example of a non-physicist confusing two ideas that may seem similar to the non-specialist but which to a physicist should not be confused:
"In the 1930s, Arthur Holmes worked out the geology of the mechanism [underpinning plate tectonics] and the fact that the earth's inner heat (like that of the sun) comes from atomic fission." p.190
Thomson, 2005: 190
The earth contains a good deal of radioactive material which, through atomic fission, heats up the earth from within. This activity has contributed to the, initially hot, earth cooling much more slowly than had once been assumed – most notably according to modelling undertaken by Thomson's namesake, Lord Kelvin.2 Kelvin did not know about nuclear fission.
But the sun is heated by a completely different kind of nuclear reaction: fusion. The immense amount of energy 'released' during this process enables stars to burn for billions of years without running out of hydrogen fuel.3
Lord Kelvin did not know about that either, leading to him suggesting
"…on the whole most probable that the sun has not illuminated the earth for 100,000,000 years, and almost certain that he has not done so for 500,000,000 years"
Thomson, 1862
Kelvin suggested this was 'almost' but not 'absolutely' certain – a good scientist should always keep an open mind to the possibility of having missed something (take note, BBC's Nick Robinson).
We now think the sun has been 'illuminating' for about 4 600 000 000 years, almost ten times as long as Kelvin's upper limit. It may seem strange that a serious scientist should refer to the sun as 'he', but this kind of personification was once common in scientific writings.
The first atomic weapons were based on fission processes of the kind used in nuclear power stations.
Hydrogen bombs are much more devastating still, making use of fusion as occurs deep in the sun.
(Image by Gerd Altmann from Pixabay)
A non-scientist may feel this conflation of fission and fusion is a minor technical detail. But it is a very significant practical distinction.
For one thing the atomic bombs that were used to devastate Hiroshima and Nagasaki were fission devices. The next generation of atomic weapons, the 'hydrogen bombs' were very much more powerful – to the extent that they used a fission device as a kind of detonator to set off the main bomb! It is these weapons, fusion weapons, which mimic the processes at the centre of stars such as the sun.
…The rusty wire that holds the cork that keeps the anger in Gives way and suddenly it's day again The sun is in the east Even though the day is done Two suns in the sunset, hmph Could be the human race is run…
From the lyrics of 'Two suns in the sunset' (Pink Floyd song) by Roger Waters
In terms of peaceful technologies, fission-based nuclear power stations, whilst not using fossil fuels, have been a major concern because of the highly radioactive waste which will remain a high health risk for many thousands of years, and because of the dangers of radiation leaks – very real risks as shown by the Three Mile Island (USA) and Windscale (England) accidents, and much more seriously at Fukushima (Japan) and, most infamously, Chernobyl (then USSR, now Ukraine). There are also serious health and human rights issues dogging the mining of uranium ore, which is, of course, a declining resource.
For decades scientists have been trying to develop, as an alternative, nuclear fusion based power generation which would be a source of much cleaner and sustainable power supplies. This has proved very challenging because the conditions under which fusion takes place are so much more extreme. Critically, no material can hold the plasma at the extreme temperatures, so it has to be magnetically suspended well away from the containment vessel 'walls'.
The tenacious nature of some misconceptions
My second point, the insidious nature of some common alternative conceptions, is a challenge for science teachers as simply giving clear, accurate presentations with good examples may not be enough to bring about change in well-established and perhaps intuitive ways of thinking, even when students study hard and think they have learnt what has been taught.
I suggested this was reflected in Prof. Thomson's text (Keith, that is, not Sir William) in his use of references to Newton's ideas about force and motion. Prof. Thomson was not as a biologist therefore seeking to avoid referring to physics, but rather actively engaging with Newton's notions of inertia and the action of forces to make his points. Yet, also, seemingly misusing Newtonian mechanics because of a flawed understanding. Likely, as with many students, Prof. Thomson's intuitive physics was so strong that although he had studied Newton's laws, and can state them, when he came to apply them his own 'common-sense' conceptions of force and motion insidiously prevailed.
The point is not that Prof. Thomson has got the physics wrong (as research suggests most people do!) but that he was confident enough in his understanding to highlight Newtonian physics in his writing and, in effect, seek to teach his readers about it.
Newton's laws
What are commonly known as 'Newton' three laws of motion' can be glossed simply as:
N1: When no force is acting, an object does not change its motion: if stationary, it remains stationary; if moving, it carries on moving at the same speed in the same direction.
Indeed, this is also true if forces are acting, but they cancel because they are balanced, i.e.,
N1': When no net (overall, resultant) force is acting, an object does not change its motion: if stationary, it remains stationary; if moving, it carries on moving at the same speed in the same direction.
N2: When a net force is acting on a body it changes its motion in a way determined by the magnitude and direction of the force. (The change in velocity takes place in the direction of the force, and at a rate depending on the magnitude of the force).
So, if the force acts along the direction of motion, then the speed will change but not direction; but if the force acts in any other direction it will lead to a change in direction.
Strictly, the law relates to the 'rate of change of momentum' but assuming the mass of the body is fixed, we can think in terms of changes of velocity. 4
N3: Forces are interactions between two bodies/objects (that attract or repel each other): the same size force acts on both. (This is sometimes unfortunately phrased as 'every action having an equal and opposite reaction') 5.
These (perhaps) seem relatively simple, but there are complications in applying them. Very simply, the first law,when applied to moving bodies does not seem to fit our experience (moving bodies often seem to come to a stop by themselves – due to forces that we do not always notice).
The second law relates an applied force to a process of change, but it is very easy to instead think of the applied force directly leading to an outcome. That is people often equate the change in direction with the final direction. The change occurs in the direction of the force: that does not mean the final direction is the direction of the force.
The third law is commonly misapplied by assuming that if 'forces come in pairs' these will be balanced and cancel out. But they cannot cancel out because they are acting on the two bodies. (If your friend hits you in the eye after one too many pedantic complaints about her science writing you cannot avoid a black eye simply by hitting her back just as hard!)
A N3 force 'pair' does not balance out!
Often objects are in equilibrium because the forces acting on them are balanced. But they are never in equilibrium just because a force on them is also acting on another body! An apple hangs from a tree because the branch pulls it up the same amount as its weight pulls it down: these are two separate forces, each of which is also acting on the other body involved (the branch, and the earth, respectively).
"Any trajectory other than a straight line must be the result of multiple forces acting together."
"the concept of 'a balance of forces' keeping the moon circling the earth and the earth in orbit around the sun…
"a Newtonian balance of forces… rocks: gradually worn down by erosion, washed into the seas, accumulating as sediments, raised up as new dry land, only to be eroded again"
The first two statements are simply wrong according to conventional physics. Curved paths are often the result of a single force acting. The earth and moon orbit because they are both the subject of unbalanced forces.
Those two statements are contrary to N1 and N2.
The third statement seemed to suggest that a balance of forces was somehow considered to bring about changes. The suggestion appeared to be that a cycle of changes might be due to a balance of forces. But I acknowledged that "this reference to Hutton's ideas seems to preview a more detailed treatment of the new geology in a later chapter in the book (that I have not yet reached), so perhaps as I read on I will find a clearer explanation of what is meant by these changes being based on a theory of balance of forces".
Now I have finished the book, I wanted to address this.
A sort of balance
Prof. Thomson discusses developing ideas in geology about how the surface of the earth came to have its observed form. Today we are familiar with modern ideas about the structure of the earth, and continental drift, and most people have seen this represented in various ways.
Image by Venita Oberholster from PixabayImage by Clker-Free-Vector-Images from PixabayOriginal images by by Michel Müller from Pixabay
However, it was once widely assumed that the earth's surface was fairly static , but had been shaped by violent events in the distant past – a view sometimes called 'catastrophism'. One much referenced catastrophe was the flood associated with the biblical character Noah (of Ark fame) that was sometimes considered to have been world-wide deluge. (Those who considered this were aware that this required a source of water beyond normal rainfall – such as perhaps vast reservoirs of water escaping from underground).
The idea that the earth was continually changing, and that forces that acted continuously over vast periods of time could slowly (much too slowly for us to notice) lead to the formation of, for example, mountain ranges seemed less feasible.
Yet we now understand how the tectonic plates float on a more fluid layer of material and how these plates slowly collide or separate with the formation of new crust where they move apart. Vast forces are at work and change is constant, but there are cyclic processes such that ultimately nothing much changes.
Well, nothing much changes on a broad perspective. Locally of course, changes may be substantial: land may become submerged, or islands appear from the sea; mountains or great valleys may appear – albeit very, very slowly. But crust that is subsumed in one place will be balanced by crust formed elsewhere. And – just as walking from one side of a small boat to another will lead to one side rising out of the water, whilst the opposite side sinks deeper into the water – as land is raised in one place it will sink elsewhere.
This is the kind of model that scientists started to develop, and which Prof. Thomson discusses.
"[Dr John Woodward (1665-1728) produced] "an ingenious theory, parts of it quite modern, parts simply seventeenth century sophistry within a Newtonian metaphor. Woodward's earth, post deluge, is stable, but not in fact unchanging. This is possible because it is in a sort of balance – a dynamic balance between opposing forces."
Thomson, 2005: 156
Plus ça change, plus c'est la même chose
James Hutton (1726 – 1797) was one of the champions of this 'uniformitarianism',
"Hutton's earth is in a constant state of flux due to processes acting over millions of years as mountains are eroded by rain and frost. In turn, the steady raising up of mountains, balances their steady reduction through erosion.
…for Hutton the evidence of the rocks demonstrated a cyclic history powered by Newtonian steady-state dynamics: the more it changed, the more it stayed the same." p.181
Thomson, 2005: 181
The more it changed, the more it stayed the same: plus ça change, plus c'est la même chose. This, of course, is an idiom that has found resonance with many commentators on the social, as well as the physical, world,
"…A change, it had to come We knew it all along We were liberated from the fold, that's all And the world looks just the same And history ain't changed 'Cause the banners, they all flown in the last war … There's nothing in the street Looks any different to me And the slogans are effaced, by-the-bye And the parting on the left Is now parting on the right And the beards have all grown longer overnight…"
From the lyrics of 'Won't get fooled again' (The Who song), by Pete Townsend
Steady states
So, there are vast forces acting, but the net effect is a planet which stays substantially the same over long periods of time. Which might be considered analogous to a body which is subject to very large forces, but in such a configuration that they cancel.
Where Prof. Thomson is in danger of misleading his reader is in confusing a static equilibrium and a macroscopic overall steady state that is the result of many compensating disturbances. This is an important difference when we consider energy and not just the forces acting.
A steady state can be maintained by nothing happening, or by several things happening which effectively compensate.
If we consider a very heavy mass sitting on a very study table, then the mass has a large weight, but does not fall because the table exerts a balancing upward reaction force. Although large forces are acting, nothing happens. In physics terms, no work is done. 6
Now consider a sealed cylinder, perfectly insulted and shielded from its surroundings, containing some water, air and too much salt to fully dissolve. It would reach a stead state where the
the mass of undissolved salt is constant
the height of the solution in the tube is constant
On a macroscopic level, nothing then happens – it is all pretty boring (especially as if the cylinder was perfectly insulated we would not be able to monitor it anyway!)
Actually, all the time,
salt is dissolving
salt is precipitating
gases from the air are dissolving in the solution
gases are leaving the solution
water is evaporating into the air
water vapour is condensing
But the rates of 1 and 2 are the same; the rates of 3 and 4 are the same; and the rates of 5 and 6 are the same. In terms of molecules and ions, there is a lot of activity – but in overall terms, nothing changes: we have a steady state, due to the dynamic equilibria between dissolving and precipitating; between dissolving and degassing; and between evaporation and condensation.
This activity is possible because of the inherent energy of the particles. In the various interactions between these particles a molecule is slowed here, an ion is released from electrical bonds – and so. But no energy transfer takes placeto or from the system, it is only constantly redistributed among the ensemble of particles. No work is done.
Cycling is hard work
But macroscopic stable states maintained by cyclic processes are not like that. A key difference is that in the geological cycles there are significant frictional effects. In our sealed cylinder, the processes will continue indefinitely as the energy of the system is constant. In the geological systems, change is only maintained because there is source of power – the sun drives the water cycle, radioactive decay in effect drives the rock cycle.
Work is done in forming new crust under the sea between two plates. More work is done pushing one plate beneath another at a plate boundary. It does not matter if the compensating changes were produced by identical magnitude forces pushing in opposite directions – these are not balanced forces in the sense of cancelling out (they act on different masses of material) – if they had been, nothing would have happened.
You cannot move tectonic plates around without doing a great deal of work – just as you cannot cycle effortlessly by using a circular track that brings you back to where you started, even though when cycling in one direction the ground was pushing you one way, and on the way back the ground was pushing you in the opposite direction! (Your tyres pushed on the track, and as Newton's third law suggests, it pushed back on the tyres in the opposite direction – but those equal forces did not cancel as they were acting on different things: or you would not have moved.)
Perhaps Prof. Thomson understands this, but his language is certainly likely to mislead readers:
"Hooke realised that there was a balance of forces: while the geological strata were being formed and mountains were raised up, at the same time the land was constantly being eroded…"
Thomson, 2005: 179
No, there was not a balance of forces.
It could be that Prof. Thomson's use of the phrase 'balance of forces' is only intended as a metaphor or an analogy. 7 However, he also repeats errors he had made earlier in the book
"the concept of 'a balance of forces' keeping the moon circling the earth and the earth in orbit around the sun"
"any trajectory other than a straight line must be the result of multiple forces acting together"
which suggests a genuine confusion about how forces act.
One of these mistakes is that planetary orbits (which require a net {unbalanced} force), are due to 'opposing forces',
"…Paley's tortured dancing on the heads of all these metaphysical pins is pre-shadowing of modern ecological thinking and a metaphysical extension of Hooke and Newton's explanation of planetary orbits in terms of opposing forces, or Woodward's theory of matter, or Hutton's geology – it is the living world as a dynamic system of force and counterforce, of checks and balances." p.242
Thomson, 2005: 242 (my emphasis)
The other was that a single force cannot lead to a curved path,
"…the philosophical concept of reduction, namely that any complex system can be reduced to the operation of simple causes. Thus the parabolic trajectory of a projectile is the product of two straight-line forces acting on each other [sic];…" p.264
Thomson, 2005: 264 (my emphasis)
Forces are interactions between bodies, they are abstractions and do not act on each other. The parabolic path is due to a single constant force acting on a body that is already moving (but not in the direction of the applied force). It can be seen as the result of the combination of a force (acting according to N2) and the body's existing inertia (i.e., N1). Prof. Thomson seems to be thinking of the motion itself as corresponding to a force, where Newton suggested that it is only a change of motion that corresponds to a force.
However, whilst Prof. Thomson is wrong, he is in good company – as one of the most common alternative conceptions reported is assuming that a moving body must be subject to a force. Which, as I pointed out last time, is not so daft as in everyday experience cars and boats and planes only keep on moving as long as their propulsion systems function (to balance resistive forces); and footballs and cricket balls and javelins that do not have a source of motive power (to overcome resistive forces) soon fall to earth. So, these are understandable and, in one sense, very forgiveable slips. It is just unfortunate they appear in an otherwise informative book about science.
Sources cited:
Thomson, K. (2005). The Watch on the Heath: Science and religion before Darwin. HarperCollins.
Thomson, W. (1862). On the Age of the Sun's Heat. Macmillan's Magazine, 5, 388-393.
Thorn, C. E., & Welford, M. R. (1994). The Equilibrium Concept in Geomorphology. Annals of the Association of American Geographers, 84(4), 666-696. http://www.jstor.org/stable/2564149
Notes
1 Although there are plenty of 'academic' books in many fields of scholarship (usually highly focused so the author is writing about their specialist work), the natural sciences tend to be communicated and debated in research journals. Most books written by scientists tend to be for a more general audience – and publishers expect popular science books to appeal to a wide readership, so these books are likely to have a much broader scope than academic monographs.
2 When he was ennobled, William Thomson chose to be called Baron Kelvin – after his local river, the river Kelvin. So the SI unit of temperature is named, indirectly, after a Scottish River.
Kelvin's reputation was such that when he modelled the cooling earth and suggested the planet was less that a 100 000 000 years old, this caused considerable concerns given that geologists were suggesting that much longer had been needed for it to have reached its present state.
4 The rate of change of momentum is proportional to the magnitude of the applied force and takes place in the direction of the applied force.
As momentum is mv, and as mass is usually assumed fixed (if the motion is well below light speeds) 'the rate of change of momentum' is the mass times the rate of change of the velocity – or ma. (F=ma.)
The key point about direction is that it is not that the body moves in the direction of the force, but the change of momentum (so change of velocity) is in the direction or the force.
As the body's momentum is a vector, and the change in momentum is a vector, the new momentum is the vector sum of these two vectors: new momentum = old momentum + change in momentum.
The object's new direction after being deflected by a force is in the direction of the new momentum
5 When there is force between two bodies (let's call them A, B) the force acting on body B is the same size as the force acting on body A, but is anti-parallel in direction.
The force between the earth and the sun acts on both (not shown to scale)
6 This is an ideal case.
A real table would not be perfectly rigid. A real table would initially distort ever so slightly with the area under the mass being ever so slightly compressed, and the weight dropping to an ever so slightly lower level. The very slight lowering of the weight does a tiny amount of work compressing the table surface.
Then, nothing more happens, and no more work is done.
7 Thorn and Welford (1994) have referred to "the fuzzy and frequently erroneous use of the term…equilibrium in geomorphology" (p.861), and how an 1876 introduction of the "concept of dynamic equilibrium resembles the balance-of-forces equilibrium that appears in dynamics, but by analogy rather than formal derivation" (p.862).
Being a science professor is no assurance of understanding Newton's mechanics
Keith S. Taber
…this author had just written that all matter is in uniform motion unless acted upon by an external force but did not seem to appreciate that any matter acted upon by an external force will not be in uniform motion
I started a new book today. 'The Watch on the Heath. Science and Religion before Darwin' had been on my pile of books to read for a while (as one can acquire interesting titles faster than find time to actually read them).
'The Watch on the Heath'
by Prof. Keith Thomson
The title is a reference to the analogy adopted at the start of William Paley's classic book on natural theology. Paley (1802) argued that if one was out walking across a heath and a foot struck an object on the ground, one would make very different assumptions if the object transpired to be a stone or a pocket watch. The stone would pass without much thought – there was no great mystery about how it came to be on the heath. But a pocket watch is an intricate mechanism composed of a multitude of especially shaped and arranged pieces fashioned from different materials. A reasonable person could not think it was an arbitrary and accidentally collated object – rather it clearly had a purpose, and so had a creator – a watchmaker.
Paley developed a detailed argument based on the analogy that organisms are like intricate mechanisms that offer obvious evidence of having been designed (Images by Thomas Wolter and Gerd Altmann from Pixabay)
Paley used this as an analogy for the complexity of the living world. Analogies are often used by teachers and science communicators as a means of making the unfamiliar familiar – a way of suggesting something that is being introduced is actually like something the audience already knows about and feels comfortable with.
Paley was doing something a little different – his readers would already know about both watches and living things, and he was developing the analogy to make an argument about the nature of living things as being designed. (Living things would be familiar, but Paley wanted to invite his reader to think about them in a way they might find unfamiliar.) According to this argument, organisms were so complex that, by analogy with a watch, it followed they also were created for a purpose, and by a creator.
Even today, Paley's book is an impressive read. It is 'one long argument' (as Darwin said of his 'Origin of Species') that collates a massive amount of evidence about the seeming design of human anatomy and the living world. Paley was not a scientist in the modern sense, and he was not even a naturalist who collected natural history specimens. He was a priest and philosopher / theologian who clearly thought that publishing his argument was important enough to require him to engage in such extensive scholarship that in places the volume gives the impression of being a medical textbook.
Paley's work was influential and widely read, but when Darwin (1859) presented his own long argument for evolution by natural selection there began to be a coherent alternative explanation for all that intricate complexity. By the mid-twentieth century a neo-Darwinian synthesis (incorporating work initiated by Mendel, developments in statistics, and the advent of molecular biology) made it possible to offer a feasible account that did not need a watch-maker who carefully made his or her creatures directly from a pre-designed pattern. Richard Dawkins perverted Paley's analogy in calling one of his books 'The Blind Watchmaker' reflecting the idea that evolution is little more than the operation of 'blind' chance.
Arguably, Darwin's work did nothing to undermine the possibility of a great cosmic architect and master craft-person having designed the intricacies of the biota – but only showed the subtlety required of such a creator by giving insight into the natural mechanisms set up to slowly bring about the productions. (The real challenge of Darwin's work was that it overturned the idea that there was any absolute distinction between humans and the rest of life on earth – if humans are uniquely in the image of God then how does that work in relation to the gradual transition from pre-human ancestors to the first humans?)
Arguably Darwin said nothing to undermine the omnipotence of God, only the arrogance of one branch of the bush of life (i.e., ours) to want to remake that God in their image. Anyway, there are of course today a range of positions taken on all this, but this was the context for my reading some questionable statements about Newtonian mechanics.
My reading went well till I got to p.27. Then I was perturbed. It started with a couple of quibbles. The first was a reference to
"…the modern world of quantum physics, where Einstein's relativity and Heisenberg's uncertainty reign."
Thomson, 2005: 27
"Er, no" I thought. Relativity and quantum theory are not only quite distinct theories, but, famously, the challenge of finding a way to make these two areas of physics, relativity theory and quantum mechanics, consistent is seen as a major challenge. The theories of relativity seem to work really well on the large scale and quantum theory works really well on the smallest scales, but they do not seem to fit together. "Einstein's relativity" is not (yet, at least) found within the "world of quantum physics".
Still, this was perhaps just a rhetorical flourish.
The Newtonian principle of inertia
But later in the same paragraph I read about how,
"Newton…showed that all matter is in uniform motion (constant velocity, including a velocity of zero) unless acted upon by an external force…Newton showed that an object will remain still or continue to move at a constant speed in the same direction unless some external force changes things."
Thomson, 2005: 27
This is known as Newton's first law of motion (or the principle of inertia). Now, being pedantic, I thought that surely Newton did notshow this.
It is fair to say, I suggest, that Newton suggested this, proposed it, mooted it; perhaps claimed it was the case; perhaps showed it was part of a self-consistent description – but I am not sure he demonstrated it was so.
Misunderstanding Newton's first law
This is perhaps being picky and, of itself, hardly worth posting about, but this provides important background for what I read a little later (indeed, still in the same paragraph):
"Single forces always act in straight lines, not circles. Any trajectory other than a straight line must be the result of multiple forces acting together."
Thomson, 2005: 27
No!
The first part of this is fair enough – a force acts between two bodies (say the earth and the sun) and is considered to act along a 'line of action' (such as the line between the centres of mass of the earth and the sun). In the Newtonian world-view, the gravitational force between the earth and sun acts on both bodies along that line of action. 1
However, the second sentence ("any trajectory other than a straight line must be the result of multiple forces acting together") is completely wrong.
These two sentences are juxtaposed as though there is a logical link: "Single forces always act in straight lines, not circles. [So therefore] any trajectory other than a straight line must be the result of multiple forces acting together." This only follows if we assume that an object must always be moving in the direction of a force acting on it. But Newton's second law tells us that acceleration (and so the change in velocity) occurs in the direction of the force.
This is confusing the sense of a change with its outcome – a bit like thinking that a 10 m rise in sea level will lead to the sea being 10 m deep, or that if someone 'puts on 20 kilos' they will weigh 200 N. A 'swing to Labour' in an election does not assure Labour of a victory unless the parties were initially on par.
The error here is like assuming that any debit from a bank account must send it overdrawn: taking £10 from a bank account means there will be £10 less in the account, but not necessary that the balance becomes -£10!
Changing direction is effortless (if there is an external force acting)
Whenever a single force acts on a moving object where the line of action does not coincide with the object's direction of travel then the object will change direction. (That is, a single force will only not lead to a change of direction in the very special case where the force aligns with or directly against to the direction of travel.) So, electrons in a cathode ray tube can be shown to follow a curved path when a (single) magnetic force is applied, and an arrow shot from a castle battlement horizontally will curve down to the grounds because of the (single) effect of gravitational force. (There are frictional forces acting as well, but they only modify the precise shape of that curve which would still be found if the castle was on a planet with no atmosphere – as long as the archer could hold her breath long enough to get the arrow away.)
The lyrics of a popular song declare "arc of a diver – effortlessly". 2 But diving into a pool is only effortless (once you have pushed off) because the diver is pulled into an arc by their gravitational attraction with the earth – so even if you dive at an angle above the horizontal, a single force is enough to change your direction and bring you down.
So, there is a mistake in the science here. Either the author has simply made a slip (which can happen to anyone) or he is operating with an alternative conception inconsistent with Newton's laws. The same can presumably be said about any editor or copy editor who checked the manuscript for the publisher.
That might not be so unlikely – as force and motion might be considered the prototype case of a science topic where there are common alternative conceptions. I have seen estimates of 80%+ of people having alternative conceptions inconsistent with basic Newtonian physics. After all, in everyday life, you give something a pull or a push, and it usually moves a bit, but then always come to a stop. In our ordinary experience stones, footballs, cricket balls, javelins, paper planes, darts – or anything else we might push or pull – fail to move in a straight line at a constant speed for the rest of eternity.
That does not mean Newton was wrong, but his ideas were revolutionary because he was able to abstract to situations where the usual resistive forces that are not immediately obvious (friction, air resistance, viscosity) might be absent. That is, ideal scenarios that probably never actually occur. (Thus my questioning above whether Newton really 'showed' rather than postulated these principles.)
So, it is not surprising an author might hold a common alternative conception ('misconception') that is widely shared: but the author had written that
all matter is in uniform motion unless acted upon by an external force
yet did not seem to appreciate the corollary that
any matter acted upon by an external force will not be in uniform motion
So, it seems someone can happily quote Newton's laws of motion but still find them so counter-intuitive that they do not apply them in their thinking. Again, this reflects research which has shown that graduates who have studied physics and done well in the examinations can still show alternative conceptions when asked questions outside the formal classroom setting. It is as if they learn the formalism for the exams, but never really believe it (as, after all, real life constantly shows us otherwise).
So, this is all understandable, but it seems unfortunate in a science book that is seeking to explain the science to readers. At this point I decided to remind myself who had written the book.
We all have alternative conceptions
Keith Thomson is a retired academic, an Emeritus Fellow at Kellog College Oxford, having had an impressive career including having been a Professor of Biology at Yale University and later Director of the Oxford University Museum and Professor of Natural History. So, here we have a highly successful academic scientist (not just a lecturer in some obscure university somewhere – a professor at both Yale and Oxford), albeit with expertise in the life sciences, who seems to misunderstand the basic laws of physics that Newton postulated back in 1687.
Prof. Thomson seems to have flaws in his knowledge in this area, yet is confident enough of his own understanding to expose his thinking in writing a science book. This, again, is what we often find in science teaching – students who hold alternative conceptions may think they understand what they have been taught even though their thinking is not consistent with the scientific accounts. (This is probably true of all of us to some degree. I am sure there must be areas of science where I am confident in my understanding, but where that confidence is misplaced. I likely have misconceptions in topics areas where Prof. Thomson has great expertise.)
A balance of forces?
This could have been just a careless slip (of the kind which once made often looks just right when we reread our work multiple times – I know this can happen). But, over the page, I read:
"…in addition to the technical importance of Newton's mathematics, the concept of 'a balance of forces' keeping the moon circling the earth and the earth in orbit around the sun, quickly became a valuable metaphor…"
Thomson, 2005: 27
Again – No!
If there is 'balance of forces' then the forces effectively cancel, and there is no net force. So, as "all matter is in uniform motion (constant velocity, including a velocity of zero) unless acted upon by an external force", a body subject to a balance of forces continues in "uniform motion (constant velocity…)" – that is, it continues in a straight line at a constant speed. It does not circle (or move in an ellipse). 3
Again, this seems to be an area where people commonly misunderstand Newton's principles, and operate with alternative conceptions. Learners often think that Newton's third law (sometimes phrased in terms of 'equal and opposite forces') implies there will always be balanced forces!
The reason the moon orbits the earth, and the reason the earth orbits the sun, in the Newtonian world-view is because in each case the orbiting body is subject to a single force which is NOT balanced by any countering force. As the object is "acted upon by an external force" (which is not balanced by any other force) it does not move "in uniform motion" but constantly changes direction – along its curved orbit. According to Newton's law of motion, one thing we can always know about a body with changing motion (such as one orbiting another body) is that the forces on it are not balanced.
But once circular motion was assumed as being the 'natural' state of affairs for heavenly bodies, and I know from my own teaching experience that students who understand Newtonian principle in the context of linear motion can still struggle to apply this to circular motion. 4
I even developed a scaffolding tool to help students make this transition, by helping them work through an example in very simple steps, but which on testing had modest effect – that is, it seemed to considerably help some students apply Newton's laws to orbital motion, but could not bridge that transition for others (Taber & Brock, 2018). I concluded even more basic step-wise support must be needed by many learners. Circular motion being linked to a net (unbalanced) centripetal force seems to be very counter-intuitive to many people.
To balance or not to balance
The suggestion that a balance of forces leads to change occurs again a little later in the book, in reference to James Hutton's geology,
"…Hutton supported his new ideas both with solid empirical evidence and an underlying theory based on a Newtonian balance of forces. He saw a pattern in the history of the rocks: gradually worn down by erosion, washed into the seas, accumulating as sediments, raised up as new dry land, only to be eroded again."
Thomson, 2005: 39
A balance of forces would not lead to rocks being "gradually worn down by erosion, washed into the seas, accumulating as sediments, raised up as new dry land, only to be eroded again". Indeed if all the relevant forces were balanced there would be no erosion, washing, sedimentation, or raising.
Erosion, washing, sedimentation, raising up ALL require an imbalance of forces, that is, a net force to bring about a change. 5
Reading on…
This is not going to stop me persevering with reading the book*, but one can begin to lose confidence in a text in situations such as these. If you know the author is wrong on some points that you already know about, how can you be confident of their accounts of other topics that you are hoping to learn about?
Still, Prof. Thomson seems to be wrong about something that the majority of people tend to get wrong, often even after having studied the topic – so, perhaps this says more about the hold of common intuitive conceptions of motion than the quality of Prof. Thomson's scholarship. Just like many physics learners – he has learnt Newton's laws, but just does not seem to find them credible.
Sources cited:
Darwin, C. (1859). The Origin of Species by Means of Natural Selection, or the preservation of favoured races in the struggle for life. John Murray.
Dawkins, R. (1988). The Blind Watchmaker. 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 University Press.
Rosen, E. (1965/1995) Copernicus on the phases and the light of the planets, in Rosen, E. (1995). Copernicus and his successors (E. Hilfstein, Ed.). The Hambledon Press.
Thomson, K. (2005). The Watch on the Heath: Science and religion before Darwin. HarperCollins.
Watts, M. and Taber, K. S. (1996) An explanatory gestalt of essence: students' conceptions of the 'natural' in physical phenomena, International Journal of Science Education, 18 (8), pp.939-954.
Notes
1 Though not in the world-view offered by general relativity where the mass of the sun distorts space-time enough for the earth to orbit.
2 The title track from Steve Winwood's 1980 solo album 'Arc of a Diver'
3 We have known since Kepler that the planets orbit the sun following ellipses (to a first order of approximation*), not perfect circles – but this does not change the fundamental point here: moving in an ellipse involves continuous changes of velocity. (* i.e., ignoring the perturbations due to the {much smaller} forces between the orbiting bodies.**)
[Added, 20220711]: these perturbations are very small compared with the main sun-planet interactions, but they can still be significant in other ways:
"…the single most spectacular achievement in the long history of computational astronomy, namely, the discovery of the planet Neptune through the perturbations which it produced in the motion of Uranus."
Rosen, 1965/1995, p.81
4 What is judged as 'natural' is often considered by people as not needing any further explanation (Watts and Taber, 1996).
5 This reference to Hutton's ideas seems to preview a more detailed treatment of the new geology in a later chapter in the book (that I have not yet reached), so perhaps as I read on I will find a clearer explanation of what is meant by these changes being based on a theory of balance of forces.* Still, the impression given in the extract quoted is that, as with orbits, a balance of forces brings about change.
How can we count the number of stars in the galaxy?
On the BBC radio programme 'More or Less' it was mooted that there might be one hundred billion (100 000 000 000) stars in our own Milky Way Galaxy (and that this might be a considerable underestimate).
Programme presenter Tim Harford was tackling a question sent in by a young listener (who is very almost four years of age) about whether there are more bees in the world than stars in the galaxy? (Spoiler alert: Prof. Catherine Heymans confessed to knowing less about bees than stars.)
Hatford asked how the 100 billion stars figure was arrived at:
"have we counted them, or got a computer to count them, or is it more a case of, well, you take a photograph of a section of sky and you sort of say well the rest is probably a bit like that?"
The last suggestion here is of course the basis for many surveys. As long as there is good reason to think a sample is representative of the wider population it is drawn from we can collect data from the sample and make inferences about the population at large.
So, if we counted all the detectable stars in a typical 1% of the sky and then multiplied the count by 100 we would get an approximation to the total number of detectable stars in the whole sky. That would be a reasonable method to find approximately how many stars there are in the galaxy, as long as we thought all the detected stars were in our galaxy and that all the stars in our galaxy were detectable.
Prof. Heymans replied
"So, we have the European Space Agency Gaia mission up at the moment, it was launched in 2013, and that's currently mapping out 1% of all the stars in our Milky Way galaxy, creating a three dimensional map. So, that's looking at 1 billion of the stars, and then to get an idea of how many others are there we look at how bright all the stars are, and we use our sort of models of how different types of stars live [sic] in our Milky Way galaxy to give us that estimate of how many stars are there."
Prof. Catherine Heymans interviewed on 'More or Less'
A tautology?
This seemed to beg a question: how can we know we are mapping 1% of stars, before we know how many stars there are?
This has the appearance of a tautology – a circular argument.
If we assume there are one hundred billion, then we need to
count one billion, and then
multiply by 100 to give…
one hundred billion.
Clearly that did not seem right. I am fairly sure that was not what Prof. Haymans meant. As this was a radio programme, the interview was presumably edited to fit within the limited time allocated for this item, so a listener can never be sure that a question and (apparently immediately direct) response that makes the edit fully reflects the original conversation.
Counting the bright ones
According to the website of the Gaia mission, "Gaia will achieve its goals by repeatedly measuring the positions of all objects down to magnitude 20 (about 400 000 times fainter than can be seen with the naked eye)." Hartman's suggestion that "you take a photograph of a section of sky and you sort of say well the rest is probably a bit like that?" seems very reasonable, until you realise that even with a powerful telescope sent outside of the earth's atmosphere, many of the stars in the galaxy may simply not be detectable. So, what we see cannot be considered to be fully representative of what is out there.
It is not then that the scientists have deliberately sampled 1%, but rather they are investigating EVERY star with an apparent brightness above a certain critical cut off. Whether a star makes the cut, depends on such factors as how bright it is (in absolute terms – which we might imagine we would measure from a standard distance 1) and how close it is, as well as whether the line of sight involves the starlight passing through interstellar dust that absorbs some (or all) of the radiation.
Of course, these are all strictly, largely, unknowns. Astrophysics relies a good on boot-strapping, where our best, but still developing, understanding of one feature is used to build models of other features. In such circumstances, observational tests of predictions from theory are often as much testing the underlying foundations upon which a model used to generate a prediction is built as that specific focal model itself. Knowledge moves on incrementally as adjustments are made to different aspects of interacting models.
Observations are theory-dependent
So, this is, in a sense, a circular process, but it is a virtuous circle rather than just a tautology as there are opportunities for correcting and improving the theoretical framework.
In a sense, what I have described here is true of science more generally, and so when an experiment fails to produce a result predicted by a new theory, it is generally possible to seek to 'save' the theory by suggesting the problem was (if not a human error) not in the actual theory being tested, but in some other part of the more extended theoretical network – such as the theory underpinning the apparatus used to collect data or the the theory behind the analysis used to treat data.
In most mature fields, however, these more foundational features are generally considered to be sound and unlikely to need modifying – so, a scientist who explains that their experiment did not produce the expected answer because electron microscopes or mass spectrometers or Fourier transform analyses do not work they way everyone has for decades thought they did would need to offer a very persuasive case.
However, compared to many other fields, astrophysics has much less direct access to the phenomena it studies (which are often vast in terms of absolute size, distance and duration), and largely relies on observing without being able to manipulate the phenomena, so understandably faces special challenges.
Why we need a theoretical model to finish the count
Researchers can use our best current theories to build a picture of how what we see relates to what is 'out there' given our best interpretations of existing observations. This is why the modelling that Prof. Heymans refers to is so important. Our current best theories tell us that the absolute brightness of stars (which is a key factor in deciding whether they will be detected in a sky survey) depends on their mass, and the stage of their 'evolution'.2
So, completing the count needs a model which allows data for detectable stars to be extrapolated, bearing in mind our best current understanding about the variations in frequencies of different kinds (age, size) of star, how stellar 'densities' vary in different regions of a spiral galaxy like ours, the distribution of dust clouds, and so forth.
…keep in mind we are off-centre, and then allow for the thinning out near the edges, remember there might be a supermassive black hole blocking our view through the centre, take into account dust, acknowledge dwarf stars tend to be missed, take into account that the most massive stars will have long ceased shining, then take away the number you first thought of, and add a bit for luck… (Image by WikiImages from Pixabay)
I have taken the liberty of offering an edited exchange
Hartford: "have we counted [the hundred billion stars], or got a computer to count them, or is it more a case of, well, you take a photograph of a section of sky and you sort of say well the rest is probably a bit like that?"
Heymans "So, we have the European Space Agency Gaia mission up at the moment, it was launched in 2013, and that's currently mapping out…all the stars in our Milky Way galaxy [that are at least magnitude 20 in brightness], creating a three dimensional map. So, that's looking at 1 billion of the [brightest] stars [as seen from our solar system], and then to get an idea of how many others are there we look at how bright all the stars are, and we use our models of how different types of stars [change over time 2] in our Milky Way galaxy to give us that estimate of how many stars are there."
No more tautology. But some very clever and challenging science.
2 Stars are not alive, but it is common to talk about their 'life-cycles' and 'births' and 'deaths' as stars can change considerably (in brightness, colour, size) as the nuclear reactions at their core change over time once the hydrogen has all been reacted in fusion reactions.
Photosynthesis illuminating a plant? (Image by OpenClipart-Vectors from Pixabay)
Analogies, metaphors and similes are used in communication to help make the unfamiliar familiar by suggesting that some novel idea or phenomena being introduced is in some ways like something the reader/listener is already familiar with. Analogies, metaphors and similes are commonly used in science teaching, and also in science writing and journalism.
An analogy maps out similarities in structure between two phenomena or concepts. This example, from a radio programme, compared the COVID pandemic with photosynthesis.
"So, what we were particularly aiming to do, was to understand the collision between a range of different political economic factors of a pre-2020 world, and how they were sort of reassembled and deployed to cope with something which was without question unprecedented.
We used this metaphor of photosynthesis because if you think about photosynthesis in relation to plants, the sun both lights things up but at the same time it feeds them and helps them to grow, and I think one of the things the pandemic has done for social scientists is to serve both as a kind of illumination of things that previously maybe critical political economists and heterodox scholars were pointing to but now became very visible to the mainstream media and to mainstream politics. But at the same time it also accentuated and deepened some of those tendencies such as our reliance on various digital platforms, certain gender dynamics of work in the household, these sort of things that became acute and undeniable and potentially politicised over the course of 20230, 2021."
Prof. Will Davies, talking on 'Thinking Allowed' 1
Will Davies, Professor in Political Economy at Goldsmiths, University of London was talking to sociologist Prof. Laurie Taylor who presents the BBC programme 'Thinking Aloud' as part of an episode called 'Covid and change'
A scientific idea used as analogue
Prof. Davies refers to using "this metaphor of photosynthesis". However he goes on to suggest how the two things he is comparing are structurally similar – the pandemic has shone a light on social issues at the same time as providing the conditions for them to become more extreme, akin to how light both illuminates plants and changes them. A metaphor is an implicit comparison where the reader/listener is left to interpret the comparison, but a metaphor or simile that is explicitly developed to explain the comparison can become an analogy.
Often science concepts are introduced by analogy to more familiar everyday ideas, objects or events. Here, however, a scientific concept, photosynthesis is used as the analogue – the source used to explain something novel. Prof. Davies assumes listeners will be familiar enough with this science concept for it to helpful in introducing his research.
Mischaracterising photosynthesis?
A science teacher might not like the notion that the sun feeds plants – indeed if a student suggested this in a science class it would likely be judged as an alternative conception. In photosynthesis, carbon dioxide (from the atmosphere) and water (usually absorbed from the soil) provide the starting materials, and the glucose that is produced (along with oxygen) enables other processes – such as growth which relies on other substances also being absorbed from the soil. (So-called 'plant foods', which would be better characterised as plant nutritional supplements, contain sources of elements such as nitrogen, phosphorus and potassium). Light is necessary for photosynthesis, but the sunlight is not best considered 'food'.
One might also argue that Prof. Davies has misidentified the source for his analogy, and perhaps he should rather have suggested sunlight as the source metaphor for his comparison as sunlight both illuminates plants and enables them to grow. Photosynthesis takes place inside chloroplasts within a plant's tissues, and does not illuminate the plant. However, Prof. Davies' expertise is in political economy, not natural science, and it was good to see a social scientist looking to use a scientific idea to explain his research.
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.
Organisations use advertising to make claims about their products and services – but how are we meant to understand such claims? (I wonder in particular how people on the autism spectrum are expected to make sense of them.)
Knowledge claims about knowledge claims
As someone who has been professionally concerned with how we understand 'knowledge' (what is it?, what counts as knowledge?) and how we identify it (can it be measured?, can we ever be sure quite what someone else knows?) I've recently been rather irritated by some rather blatantly naive claims made in adverts that I have been repeatedly exposed to when settling down for some relaxing evening viewing. These were not about a product as such, but about the apparently exceptional expertise of the company staff.
I live in a state where there is an advertising standards authority (the ASA) to which consumers can make complaints, and which can take action on misleading advertising.
Here are some selected points from the regulator's website (accessed 21st May, 2022) regarding misleading advertisements:
• The ASA will take into account the impression created by advertisements as well as specific claims. It will rule on the basis of the likely effect on consumers, not the advertiser's intentions.
• Advertisements must not materially mislead or be likely to do so.
• Advertisements must not mislead consumers by omitting material information. They must not mislead by hiding material information or presenting it in an unclear, unintelligible, ambiguous or untimely manner.
• Subjective claims must not mislead the audience; advertisements must not imply that expressions of opinion are objective claims.
• Advertisements must state significant limitations and qualifications.
• Advertisements must not mislead by exaggerating the capability or performance of a product or service.
• Advertisements must not suggest that their claims are universally accepted if a significant division of informed or scientific opinion exists.
Given these points, I feel that some rather specific and unequivocal claims made by an organisation called 'Carpetright' are extremely dubious.
However, I should also note another significant statement which potentially undermines the ASA's ability to apply such principles strictly:
"Obvious exaggerations ('puffery') and claims that the average consumer who sees the advertisement is unlikely to take literally are allowed provided they do not materially mislead."
So, this seems to suggest that claims can be made which are not actually true as long as the 'average consumer' will recognise them as not meant to be trusted and believed. Hm.
At one level, this makes sense. If an advertiser hires an actor to dress up in aluminium foil and announce "I am Thor, God of Thunder, and I will bring my wrath upon you all, except those wearing Taber raincoats who are protected from my powers" then clearly they are not expecting the audience to believe they are seeing a supernatural entity with Godly powers of destruction from which they can be protected by buying the right rainwear. They are expected to interpret this along the lines "our raincoats are pretty effective at keeping you dry when it is raining". As there is no intent to deceive, and as a reasonable person (perhaps that 'average consumer') is unlikely to perceive this as an objective knowledge claim, then this is no more a lie than when an actor plays a part in a fictional play or film.
It seems widely accepted that advertising claims operate in a register rather different from clear, honest claims with relevant caveats. But then how does the 'average consumer' know which statements are meant to be taken seriously as knowledge claims? (Thor Image by Nico Wall from Pixabay; Clothing image by Any_Banany_Style from Pixabay)
But I am worried about this 'get-out clause' as it potentially offers a defence for all kinds of claims that cannot be objectively supported.
Who knows the most?
I have been seeing the particularly irritating advertisements regularly for some time now, and had been so grated by the claims in them – in particular by the extremely implausible nature of them when considered collectively – that when I sat down to watch a programme yesterday I actually made a note of the claims in a succession of small sponsor's advertisements positioned at the start and end of each commercial break. (I usually record programmes and fast-forward through such breaks, but these 'sponsoring' adverts are directly segued to the programme content so hard to completely avoid. That said, when you do not use the fast-forward they do offer an obvious indication when to press the mute button as the programme has paused or is just about to recommence.) During the programme the set of claims were cycled through twice (and one of the claims was slightly different in nature to the others and I will leave aside).
The first commercial break was announced with the claim that
"no one knows more about floors than Jeff"
Claim made by 'Careptright'
This is presented as an unqualified and objective statement.
For anyone who has undertaken research to explore the knowledge of learners, this raises a whole array of questions.
What is meant by knowledge in this claim?
Traditionally knowledge is meant to be true justified belief. That is, Jeff has knowledge about floors to the extent that he has beliefs about floors that are are both justified and true.
Justified belief
What would be a justified belief?
Well there might be differences of opinion here. Some might suggest that Jeff's beliefs are only justified if they are based on well interpreted empirical evidence. He has been down on floors getting his hands dirty investigating them. Alternatively, others might feel the main source of knowledge is rational reflection – so Jeff needs to have undertaken some careful and valid philosophical investigation into floors to have worthwhile knowledge. These two sources are sometimes seen as opposed – empiricists versus rationalists.
For a scientist, knowledge is based on an ongoing enquiry where rational thought and reflection, and empirical investigation, are employed iteratively. (That is, science uses a bit of both, tending to shift between the two to build up understanding over time.)
Another source of knowledge might be authority. Perhaps Jeff has been to 'floor' college and been taught by acknowledged experts? Perhaps he has carefully studied the top texts on floors and regularly tops up his expertise on professional development courses.
The founders of the Royal Society of London suggested that scientists should take no one's word for things, but rather test things out for themselves. Whilst that is a fine sentiment, it is totally impractical today, as science would never progress if all novice scientists were expected to check for themselves every piece of theory they might apply in their work. They would unlikely ever get to do anything new before retirement. Rather they can accept, on authority, that hydrogen is an element, that current in a metal wire is due to a flow of electrons, that all frogs have hearts 1, and so on. They do this on authority of their teachers and the texts they read.
Of course, this raises the problem of who can be taken as an authority.
Science is a community activity which largely works by consensus but allowing enough room for dissent to hopefully ensure it does not become dogmatic. (Sometimes it fails, but this combination of authority, logical thought, and empirical investigation is surely the best way anyone has yet come up with of finding out about the natural world.)
What is a true belief?
There is of course a distinction between a truly held belief, and a true belief. Some people truly believe they have been abducted by aliens, who having come all this way, have nothing better to do than borrow people overnight and probe them a little before returning them to their beds. No matter how much these people genuinely believe this to have happened it is not a true belief unless they really have been molested by aliens that have the technology to travel galactic distances, abduct people from inside their homes without raising the alarm, and medically examine humans without leaving any traces; but sadly have not yet found a way to do this without sufficiently anaesthetising their victims to ensure they are unaware.
A truly held belief is not necessarily true (Image by Dantegráfico from Pixabay)
Perhaps this is actually the case. If this truly happens, then someone who genuinely strongly believes they have been a victim, and has sufficient grounds to be justified in that belief (whatever we might decide would count here), can be said to have true knowledge.
But only if we know this is indeed what happened. But there is a clear danger of a vicious circle in making that judgement. We can only decide someone has genuine knowledge because we have genuine knowledge and their beliefs match our knowledge. But we can only be said to have such knowledge, if we have a true, justified, belief, which surely requires someone else to check our beliefs are true. And that some has to be someone who knows the truth – i.e., can be judged to have the knowledge.
One this basis only God or someone arrogant enough to think themselves similarly incapable of error can make this call.
Do scientists have knowledge?
It would seem that if we apply the notion of true, justified, belief strictly, then we can never claim to have knowledge. Then 'human knowledge' would only exist as some kind of idea, like an ideal gas or a canonical concept (Taber, 2019), which is a useful referent to compare things against, but not something we can ever expect to have.
That would be a reasonable way to use the word – but in actual public discourse knowledge is talked about as if it is obtainable – so experts are said to have expert knowledge (not just expert beliefs or expert opinions).
It is widely accepted that scientific knowledge claims are NOT claiming knowledge in that ideal sense – not absolute, certain knowledge, but provisional knowledge: knowledge as our best current understanding, considered to be a sufficient basis for action in the world, but always open to review.
As one philosopher of science noted:
"Assume somebody points out that certainty is an essential part of knowledge in the sense that the meaning of the word 'knowledge' contains the idea of certainty. The answer is very simple: we have decided against the idea of certainty … We have thereby also decided against knowledge in the sense alluded to. If certainty is part of knowledge, then we simply do not want to know in this sense."
So, scientific knowledge is evidence-based, rationally argued, and developed within an authoritative background tradition, and so considered to be reliable and trustworthy – but is strictly something other than true, justified, belief. Indeed, arguably we should not consider scientific knowledge as beliefs: scientists commit to certain ideas as well supported and worthy of provisional assent – but not as beliefs.
In science education, the teacher's job is not to persuade students to believe in scientific ideas (whether seemingly controversial, such as natural selection, the big bang, or well-established such as combustion being usually a reaction with oxygen), but rather to understand why scientists have adopted certain ideas as provisional knowledge whilst remaining critical and open to new evidence or interpretations (Taber, 2017).
Assessing knowledge
If we accept that people do have knowledge (an ontological judgement), this does not imply we can easily investigate it (an epistemological matter). Science teachers assess students' science knowledge all the time, so in practice we assume that (i) in principle we can identify/examine someone else's knowledge, and that (ii) we can do this in a sufficiently valid and reliable way that we think it is morally acceptable for teachers and examiners to score and grade learners for their knowledge.
I am not disputing that is so in practice, BUT undertaking research into learners' science knowledge makes us very aware of the limitations to processes of eliciting and assessing other people's knowledge. We need probes (e.g., questions) that are understood as intended, participants motivated to reveal their thinking, and the ability to interpret responses. I am not suggesting this is impossible, but, as with any research to measure something, it relies on valid and well-calibrated instrumentation, appropriate background theory, and is always subject to limits on precision.
This is disguised sometimes in the kind of 'shorthand' used in many research reports which can include bland summary statements (of the kind '76% of the participants had a good understanding of acidity, but 12% held a common misconception') that tends to sound more absolute and precise than is possible, and which often clump together considerable diversity of knowledge and understanding within a single class such as 'misconception' or 'sound knowledge' (Taber, 2013).
In my doctoral research I studied students' understanding of chemical bonding in depth, and this reinforced the idea that each of us has unique and idiosyncratic knowledge. I found much commonality in student thinking and indeed something of a 'common' alternative conceptual framework , yet when one investigates thinking in depth (rather than just using a questionnaire with objective questions) it become clear that even in the same class, no two students have precisely the same knowledge of a topic. That certainly applied to 'chemical bonding' and I would expect it applies equally as well to other domains – including floors!
Can knowledge be quantified?
But given that everyone's knowledge is unique, with its own nuances, gaps, and deviations from some ideal canonical account, does it even make sense to try to quantity knowledge? When we appreciate some of the qualitative variation between individual epistemic agents (i.e., 'knowers') it starts to look rather questionable whether it makes sense to be satisfied with any quantitative score meant to reflect relative levels of knowledge (like test scores). This makes a claim like "no one knows more about floors than Jeff" seem, at best, a little simplistic.
A barely plausible coincidence
Yet, at the end of the first commercial break, the same sponsor made another claim:
"no one knows more about floors than Roger"
Claim made by 'Careptright'
As of itself, this claim seems just as dubious as the claim about Jeff.
But it is when they are taken together, that they really stretch credibility. It we treat these claims at face value:
No one knows more about floors than Roger. So, this includes Jeff. Jeff does not know more about floors than Roger.
Yet we are also told no one knows more about floors than Jeff. And this must include Roger. So, Roger does not know more about floors than Jeff.
Clearly the only way to accept both these claims is to assume that Roger and Jeff know exactly as much about floors as each other.
We have to assume here then that it makes sense to quantify domain knowledge (in the floors domain at least) and that sufficiently accurate measurements of domain knowledge can be made to confidently conclude that Roger and Jeff know precisely equal amounts.
We are not told they know everything about floors. Perhaps each only knows 10% of what it is possible to know about floors, in which case we might wonder to what extent their knowledge overlaps or is complementary. If Jeff knows 10% of all that could be known about floors, and Roger also knows 10% of all that could be known about floors, then between them they must know between 10-20% of the total domain knowledge.
Stretching credulity further
I had barely had time to ponder all this when the next commercial break arrives with a new claim:
"no one knows more about floors than Donald"
Claim made by 'Careptright'
So, an even more unlikely scenario is presented.
No one knows more about floors than Donald. So, this includes Jeff. Jeff does not know more about floors than Donald.
And this also includes Roger. Roger does not know more about floors than Donald.
Yet we are also told no one knows more about floors than Jefff. And this must include Donald. So, Donald does not know more about floors than Jeff.
And no one knows more about floors than Roger. So, this also includes Donald. Donald does not know more about floors than Roger.
Clearly the only way to accept all these claims is to assume that Donald and Roger and Jeff know exactly as much about floors as each other.
How likely is it that there are three people in the world who equally know so much about floors that no one else in the world knows more about floors than them?
I guess this deepens on just how complex a domain floor knowledge is. In many distributions that occur 'naturally' there is something of a bell-curve where a lot of people clump around the middle of the distribution, so they are fairly typical or average in that regard, and just a few people fall at the extremes.
A 'normal' distribution (Image by OpenClipart-Vectors from Pixabay)
The more possible states there are in the distribution, the more likely that the highest occupied state will have relatively low occupancy. Yet if there are only a small number of states, there will be less options and higher frequencies in specific states. That is, there will be what is known as a 'ceiling' effect. A ceiling effect occurs in tests if the questions are too easy allowing many candidates to obtain the maximum score. Such a test does not discriminate well between the most capable and less capable candidates.
There are billions of people on earth, so perhaps it is not so surprising there might be three people tied for top rating in the area of floor domain knowledge – or even more than three – so it is not impossible that these three (Jeff, Roger, Donald) all work for the same company that have highly trained them within the domain.
Beyond belief?
But then at the end of the commercial break we are told
"no one knows more about floors than Shirley"
Claim made by 'Careptright'
So, I will not go through all the argument again as clearly we are being told that no one knows more about floors than Shirley, but there are other people (Jeff, Roger, Donald) who also are not exceeded in their domain knowledge, so we conclude that there are at least four people in the world who have equal domain knowledge to each other, whilst not being exceeded in domain knowledge by anyone else.
Yet there are further commercial breaks, and further bold claims:
"no one knows more about floors than Michael"
Claim made by 'Careptright'
and
"no one knows more about floors than Johnny"
Claim made by 'Careptright'
and
"no one knows more about floors than Kate"
Claim made by 'Careptright'
and
"no one knows more about floors than Tess"
Claim made by 'Careptright'
and
"no one knows more about floors than Denise"
Claim made by 'Careptright'
So, it seems that there are at least nine people working for this one organisation who are not exceeded in their domain knowledge by anybody else in the world. So, in the domain of floors
And no one knows more about floors than any of them.
This seems pretty unlikely – even fantastic, perhaps.
There are several ways to interpret this.
It is an advert meant to persuade simple people, so impressive claims are made to deceive them given that the advertisers assume their audience are too stupid to think critically and so appreciate they are being lied to.
Alternatively, perhaps as an advert, this is knowingly making nonsense claims that the audience are meant to see through, knowing that the point of the advert is to plant an idea and brand in the mind; and the audience are not expected or required to believe it. It is not deception, but what ASA call 'puffery' – something so obviously silly that no one is expected to take it seriously (or spend time critically analysing it for a blog). Who knows, perhaps there are no such people as Jeff and his colleagues, and their parts are played by actors!
But there is a third possibility.
Shoot high, aim low
There is one way that we might reasonably expect that a large number of people might be said to have such domain knowledge that it is not exceeded by any one else (and therefore have equal degrees of domain knowledge).
Consider a domain that is extremely simple and restricted.
We might imagine a knowledge domain with a very small number of possible knowledge elements. We can certainly imagine an artificial case – such as regarding one of those manufactured concepts used in some psychological research into concept formation.
For example consider the knowledge domain of recirgres
An example of a recirgre
Let us consider that a recirgre is a red circle on a green background. Perhaps there are only three things to be known about recirgres:
they are circular
they are red
the are found on green backgrounds
There are only eight basic knowledge states here, offering four quantitative levels of domain knowledge (making a ceiling effect likely):
knowing none of the three elements
knowing only one of the elements (three options)
knowing two of the three elements (three options)
knowing all three elements
The researcher in me would point out that even here there is more potential diversity in knowledge (e.g., one person may know only that recirgre are red; another may know recirgres are red and believe they are square; another may may know recirgres are red and think they may be any oval shape including circles…but here all such options count as having one element of domain knowledge; then again, perhaps someone thinks recirgres are red circles on green backgrounds and that putting one on a North facing wall in every room of a house will bring good luck; and someone else that recirgres are red circles on green backgrounds, but they used to be princesses before they were turned into recirgres by evil stepmothers – but in either case that's just the same maximum score of 3/3 in this assessment).
If we examined the knowledge of a large number of people that had studied the topic of recirgres we might find many top scorers of whom we could say "no one knows more about recrigres than…"- because of the low ceiling in this limited knowledge domain.
Some areas of expertise involve more complex and extensive knowledge domains than others (Images by Ahmad Ardity and Peggy und Marco Lachmann-Anke from Pixabay )
So perhaps the same is true of floors. Perhaps there's not actually that much that can be known about floors, so quite a few people who work in floors and are trained up in the trade know at least as much as anyone else does. It does not take long for someone who works in floors to hit the ceiling.
Perhaps. I'd rather think that than that my viewing is being interrupted by a successions of claims that I am simply meant to dismiss as fictions that are acceptable because they are "obvious exaggerations" ("puffery") and "claims that the average consumer who sees the advertisement is unlikely to take literally" because consumers know that claims made by advertisers like 'Carpetright' are not supposed to be truthful and taken seriously. So, perhaps the advertisers do not think we are stupid, but rather that we are clever enough to know their claims are not meant to have any genuine substantive content.
But if that is so, they are not trying to deceive us, but rather to manipulate us more insidiously.
1 Perhaps these examples seem like 'facts' rather than theories, but they can only be facts within a given theoretical context. So, to call hydrogen an element one needs a theoretical perspective on what an element is.
I've used the frog heart example to illustrate how scientific knowledge is not just as matter of being able to generalise from having examined some examples (induction):
"We might imagine a natural scientist, a logician, and a sceptical philosopher, visiting the local pond. The scientist might proclaim, "see that frog there, if we were to dissect the poor creature, we would find it has a heart". The logician might suggest that the scientist cannot be certain of this as she is basing her claim on an inductive process that is logically insecure. Certainly, every frog that has ever been examined sufficiently to determine its internal structure has been found to have a heart, but given that many frogs, indeed the vast majority, have never been specifically examined in this regard, it is not possible to know for certain that such a generalisation is valid. (The sceptic, is unable to arbitrate as he simply refuses to acknowledge that he knows there is a frog present, or indeed that he can be sure he is out walking with colleagues who are discussing one, rather than perhaps simply dreaming about the whole episode.)
The use of induction here, assumed by the logician to be the basis of the scientist's claim, might take the form:
1. a great many frogs have been examined, at different times and places, in sufficient detail to know if they have hearts;
2. each and everyone of these frogs,without exception, has been found to have a heart;
3. therefore, we can assume all frogs have hearts;
4. this, in front of us, is a frog,
5. therefore, it has a heart.
A key question then seems to be: under what circumstances can it be assumed that a property measured for some instance or specimen (something conceptualised as a member of some type or class) also applies to all other instances of the same type? …
The response is that we are not actually here using a process of induction that assumes if we look at sufficient examples we can make a generalisation across the class: rather we are using theoretical considerations. We assume that 'frog' is a kind or type such that as part of its essence (related to what makes it a frog) it necessarily has a heart. …
Frogs are a type of animal that is part of a larger group that share the same kind of circulatory system based on blood vessels and a heart to pump the blood around. We do not have to test every frog, because this type of anatomy and physiology is necessary (essential) to being a frog: it is part of the essence, the very nature, of frogness. So, the hypothetical scientist was arguing that the frog is a natural kind: a particular type of thing that exists in nature and that has certain necessary aspects, such that as long as we know we have a frog, we know these aspects will be found. So, the logical chain is something like:
1. frogs are recognised as making up a natural kind;
2. one of the necessary features of frogs is the presence of a heart;
3. therefore, we can assume all frogs have hearts;
4. this, in front of us, is a frog;
5. therefore, it has a heart.
This is not generalisation by traditional induction, but generalisation by deduction from theoretical considerations.
The point is NOT that there has not been a generalisation from examining other specimens of frog, but rather that this by itself is insufficient unless located in a particular theoretical perspective.
One of the supposed features of scientific knowledge is that it is always, strictly speaking, provisional. Science seeks generalisable, theoretical knowledge – and no matter how strong the case for some general claim may seem, a scientist is supposed to be open-minded, and always willing to consider that their opinion might be changed by new evidence or a new way of looking at things.
Perhaps the strongest illustration of this is Newtonian physics that seemed to work so well for so many decades that for many it seemed unquestionable. Yet we now know that it is not a precise account that always fits nature. (And by 'we know' I mean we know in the sense of having scientific knowledge – we think this, and have very strong grounds to think this, but reserve the right to change our minds in the light of new information!)
When science is presented in the media, this provisional nature of scientific knowledge – with its inbuilt caveat of uncertainty – is often ignored. News reports, and sometimes scientists when being interviewed by journalists, often imply that we now know…for certain… Science documentaries are commonly stitched together with the trope 'and this can only mean' (Taber, 2007) when any scientist worth their salt could offer (even if seemingly less feasible) alternative scenarios that fit the data.
One might understand this as people charged with communicating science to a general audience seeking to make things as simple and straightforward as possible. However it does reinforce the alternative conception that in science theories are tested allowing them to be straightforwardly dismissed or proved for all time. What is less easy to understand is why scientists seeking to publish work in academic journals to be read by other scientists would claim to know anything for certain – as that is surely likely to seem arrogant and unscientific to editors, reviewers, and those who might read their published work
Science that is indisputable
So, one of two things that immediately made me lack confidence in a published paper about the origin of SARS-CoV-2, the infectious agent considered responsible for the COVID pandemic (Sehgal, 2021), was that the first word was 'Undisputedly'. Assuming the author was not going to follow up with Descartes' famous 'Cogito' ("Undisputedly… I think, therefore I am"), this seemed to be a clear example of something I always advised my own research students to avoid in their writing – a hostage to fortune.
A bold first sentence for this article in a supposedly peer-reviewed research journal
The good scientist learns to use phrases like "this seems to suggest…" rather than "I have therefore proved beyond all possible doubt…"!
Prestigious research journals are selective in what they publish – and reject most submissions, or at least require major revisions based on reviewer evaluations. Predatory journals seek to maximise their income from charging authors for publication; and so do not have the concern for quality that traditionally characterised academic publishing. If some of the published output I have seen is a guide, some of these journals would publish virtually anything submitted regardless of quality.
Genetic relatedness of bats and viruses
Now it would be very unfair to dismiss a scientific article based purely on the first word of the abstract. Even if 'undisputedly' is a word that does not sit easily in scientific discourse, I have to acknowledge that writing a scientific paper is in part a rhetorical activity, and authors may sometimes struggle to balance the need to adopt scientific values (such as always being open to the possibility of another interpretation) with the construction of a convincing argument.
"Undisputedly, the horseshoe bats are the nearest known genetic relatives of the Sars-CoV-2 virus."
Sehgal, 2021, p.29 341
Always start a piece of writing with a strong statement
Closest genetic relatives?
Okay, I was done.
I am not a biologist, and so perhaps I am just very ignorant on the topic, but this seemed an incredible claim. Our current understanding of the earth biota is that there has (probably) been descent from a common ancestor of all living things on the planet today. So, just as I am related, even if often only very distantly, to every other cospecific specimen of Homo sapiens on the planet, I am also related by descent from common ancestors (even more distantly) to every chimpanzee, indeed every primate, every mammal, every chordate; indeed every animal; plus all the plants, fungi, protists and monera.
But clearly I share a common ancestor with all humans in the 'brotherhood of man' more recently than all other primates, and that more recently than all other mammals. And when we get to the non-animal kingdoms we are not even kissing cousins.
And viruses – with their RNA based genetics? These are often not even considered to be living entities in their own right.
There is certainly a theory that there was an 'RNA world', a time when some kind of primitive life based on RNA genes existed from which DNA and lifeforms with DNA genomes later evolved, so one can stretch the argument to say I am related to viruses – that if one went back far enough, both viruses and humans (or viruses and horseshoe bats, more to the point of the claim in this article) around today could be considered to be derived from a common ancestor, and that this is reflected in patterns that can be found in their genomes today.
The nearest genetic relative to SARS-CoV-2 virus?
The genome of a virus is not going to be especially similar to the genome of a mammal. The SARS-CoV-2 virus is a single stranded RNA virus which will be much more genetically similar to other such viruses that to organisms with double stranded DNA. It is famously a coronavirus – so surely it is most likely to be strongly related to other coronaviruses? It is called 'SARS-CoV-2' because of its similarity to the virus that causes SARS (severe acute respiratory syndrome): SARS-CoV. These seems strong clues.
And the nearest genetic relative to horseshoe bats are…
And bats are mammals. The nearest relatives to any specific horseshoe bat are other bats of that species. And if we focus at the species level, and ask what other species would comprise the nearest genetic relatives to a species of horseshoe bats? I am not an expert, but I would have guessed other species of horseshoe bat (there are over a hundred such species). Beyond that family – well I imagine other species of bat. Looking on the web, it seems that Old World leaf-nosed bats (and not viruses) have been mooted from genetic studies (Amador, Moyers Arévalo, Almeida, Catalano & Giannini, 2018) as the nearest genetic relatives of the horsehoe bats.
Annotated copy of Figure 7 from Amador et al., 2018
So, although I am not an expert, and I am prepared to be corrected by someone who is, I am pretty sure the nearest relative that is not a bat would be another mammal – not a bird, not a fish, certainly not a mollusc or insect. Mushrooms and ferns are right out of contention. And, no, not a virus. 1
Judge me on what I mean to say – not what I say
Perhaps I am being picky here. A little reflection suggests that surely Sehgal (in stating that "the horseshoe bats are the nearest known genetic relatives of the Sars-CoV-2 virus") did not actually mean to imply that "the horseshoe bats are the nearest known genetic relatives of the Sars-CoV-2 virus", but rather perhaps something along the lines that an RNA virus known to infect horseshoe bats was the nearest known genetic relative of the Sars-CoV-2 virus.
Perhaps I should have read "the horseshoe bats are the nearest known genetic relatives of the Sars-CoV-2 virus" as "the horseshoe bats are hosts to the nearest known genetic relatives of the Sars-CoV-2 virus"? If I had read on, I would have found reference to a "bat virus RaTG13 having a genome resembling the extent of 98.7% to that of the Sars-CoV-2 virus" (p.29 341).
Yet if a research paper, that has supposedly been subject to rigorous peer review, manages to both misrepresent the nature of science AND make an obviously factually incorrect claim in its very first sentence, then I think I can be forgiven for suspecting it may not be the most trustworthy source of information.
Work cited
Amador, L. I., Moyers Arévalo, R. L., Almeida, F. C., Catalano, S. A., & Giannini, N. P. (2018). Bat Systematics in the Light of Unconstrained Analyses of a Comprehensive Molecular Supermatrix. Journal of Mammalian Evolution, 25(1), 37-70. https://doi.org/10.1007/s10914-016-9363-8
Sehgal, M.L. (2021) Origin of SARS-CoV-2: Two Schools of Thought, Biomedical Journal of Scientific & Technical Research, July, 2020, Volume 37, 2, pp 29341-29356
1 It is perfectly possible logically for organism Y (say a horseshoe bat) to be the closest genetic relative of organism X (say a coronavirus) without organism X being the closest genetic relative of organism Y. (By analogy, someone's closest living genetic relative could be a grandchild whose closest genetic relative is their own child or their parent that was not a child of that grandparent.) However, the point here is that bat is not even quite closely related to the virus.
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".
Can we be certain about something that happened half a million years ago?
Keith S. Taber
What was going on in Java when Homo erectus lived there? (Image by Kanenori from Pixabay )
About half a million years ago a hominid, of the Homo erectus species, living in Java took a shell and deliberately engraved a mark on it. Now, I was not there when this happened, so my testimony is second hand, but I can be confident about this as I was told by a scientist that she was sure that this definitely happened.
"…we knew for sure that it must have been made by Homo erectus"
But how can we be so sure about something alleged to have occurred so long ago?
"A long time ago [if not] in a galaxy far, far away…." the skull of a specimen of Homo erectus (Image by Mohamed Noor from Pixabay ) [Was this an inspiration for the Star Wars stormtrooper helmet?]
I doubt Fifi would be convinced.1 Fifi was a Y12 student (c.16 years old) interviewed as part of the LASAR project who had reservations about palaeontology as it did not provide certain scientific knowledge,
"I like fossils though, I think they're interesting but I don't think I'd really like [working as a palaeontologist]…I don't think you could ever really know unless you were there… There'll always be an element of uncertainty because no matter how much evidence you supply there will always be, like, doubt because of the fact that you were never there…there'll always be uncertainty."
Learners can have alternative conceptions of the nature of science, just as much as they often do for forces or chemical bonding or plant nutrition. They often think that scientific knowledge has been 'proved', and so is certain (e.g., Taber, Billingsley, Riga & Newdick, 2015). An area like palaeontology where direct observation is not possible may therefore seem to fall short of offering genuine scientific knowledge.
The uncertain nature of scientific knowledge
One key feature of the nature of science is that it seeks to produce general or theoretical knowledge of the natural world. That is, science is not just concerned with providing factual reports about specific events but with developing general accounts that can explain and apply to broad categories of objects and events. Such general and theoretical knowledge is clearly more useful than a catalogue of specific facts – which can never tell us about the next occasion or what might happen in hypothetical situations.
However, a cost of seeking such applicable and useful knowledge is that it can never be certain. It relies on our ways of classifying objects and events, the evidence we have collected so far, our ability to spot the most important patterns -and the deductions this might support. So, scientific knowledge is always provisional in the sense that it is open to revision in response to new data, or new ways of thinking about existing data as evidence.
Yet often reports of science in the media give the impression that science has made absolute discoveries. Some years ago I wrote about the tendency in science documentaries for the narrative to be driven by links that claimed "...this could only mean…" when we know that in science the available data always underdetermines theory (Taber, 2007). Or, to put it another way, we could always think up other ways of explaining the data. Sometimes these alternatives might seem convoluted and unlikely, but if we can suggest a possible (even when unconvincing) alternative, then the available data can never "only mean" any one particular proposed interpretation.
The scientist concerned was J.C.A (José) Joordens who is Professor in Hominin Paleoecology and Evolution, at Maastricht University. Prof. Joordens holds the Naturalis Dubois Chair in Hominin Paleoecology and Evolution. The reference to Dubois relates to the naturist responsible for finding a so-called 'missing link' in the chain of descent to modern humans,
"One of the most exciting episodes of palaeoanthropology was the find of the first transitional form, the Pithecanthropus erectus, by the Dutchman Eugène Dubois in Java during 1891-1892. …Besides the human remains, Dubois made a large collection of vertebrate fossils, mostly of mammals, now united in the so-called Dubois Collection."
de Vos, 2004
The Java man species, Pithecanthropus erectus (an upright ape/mokey-man), was later renamed as Homo erectus, the upright man.
On an edition of BBC Radio 4's 'In Our Time' taking 'Homo erectus' as its theme, Prof. Joordens explained how some fossil shells collected by Dubois as part of the context of the hominid fossils had remained in storage for over a century ("The shells had been, well, shelved…"!), before a graduate student set out to photograph them all for a thesis project. This led to the discovery that one of the shells appeared to have been engraved.
This could only mean one thing…
This is what Prof. Joordens told the host, Melvyn Bragg,
"One shell that had a very strange marking that we could not understand how it ended up there…
It was geometric, like a W, and this is of course something that animals don't produce. We had to conclude that it must have been made by Homo erectus. And it must have been a very deliberate marking because of, we did experimental research trying to replicate it, and then we actually found it was quite hard to do. Because, especially fresh shells, they have a kind of organic exterior, and it's hard to push some sharp objects through and make those lines, so that was when we knew for sure that it must have been made by Homo erectus."
Prof. José Joordens talking on 'In Our Time'
We may consider this claim to be composed of a number of components, such as:
There is a shell with some 'very strange' markings
The shell was collected in Java in the nineteenth century
The shell had the markings when first collected
The markings were not caused by some natural phenomenon
The markings were deliberate not accidental
The markings were made by a specimen of Homo erectus
A sceptic might ask such questions as
How can we be sure this shell was part of the original collection? Could it have been substituted by mistake or deliberately?
How do we know the marks were not made more recently? perhaps by someone in the field in Java, or during transit form Java to the Netherlands, or by someone inspecting the collection?
Given that even unusual markings will occur by chance occasionally, how can we be certain these markings were deliberate? Does the mark really look like a 'W 'or might that be an over-interpretation. 2
And so forth.
It is worth bearing in mind that no one noticed these markings in the field, or when the collection was taken back to the Netherlands – indeed Prof. Joordens noted she had carried the shell around in her backpack (could that have been with an open penknife?) unaware of the markings
Of course, Prof. Joordens may have convincing responses to many of these questions – but a popular radio show is not the place to detail all the argument and evidence. Indeed, I found a report in the top journal Nature ('Homo erectus at Trinil on Java used shells for tool production and engraving') by Prof. Joordens and her team 3, claiming,
"One of the Pseudodon shells, specimen DUB1006-fL, displays a geometric pattern of grooves on the central part of the left valve [*]. The pattern consists, from posterior to anterior, of a zigzag line with three sharp turns producing an 'M' shape, a set of more superficial parallel lines, and a zigzag with two turns producing a mirrored 'N' shape. Our study of the morphology of the zigzags, internal morphology of the grooves, and differential roughness of the surrounding shell area demonstrates that the grooves were deliberately engraved and pre-date shell burial and weathering"
It may seem most likely that the markings were made by a Homo erectus, as no other explanation so far considered fits all the data, but theory is always under-determined – one can never be certain another scenario might be found which also fits the known facts.
Strictly, Prof. Joordens' contradicts herself. She claims the marks are "something that animals don't produce" and then claims an animal is responsible. She presumably meant that no non-hominid animal makes such marks. Even if we accept that (and, as they say, absence of evidence is not evidence of absence 4), can we be absolutely certain some other hominid might not have been present in Java at the time, marking the odd shell? As the 'In Our Time' episode discussed, Homo erectus often co-existed with other hominids.
Probably not, but … can we confidently say absolutely, definitely, not?
As Fifi might say: "I don't think you could ever really know unless you were there".
My point is not that I think Prof. Joordens is wrong (she is an expert, so I think she is likely correct), but just that her group cannot be absolutely certain. When Prof. Joordens says she knows for sure I assume (because she is a scientist, and I am a scientist) that this means something like "based on all the evidence currently available, our best, and only convincing, interpretation is…" Unfortunately lay people often do not have the background to insert such provisos themselves, and so often hear such claims literally – science has proved its case, so we know for sure. Where listeners already think scientific knowledge is certain, this misconception gets reinforced.
Meanwhile, Prof. Joordens continues her study of hominids in Java in the Studying Homo erectus Lifestyle and Location project (yes, the acronym is SHeLL).
Joordens, J., d'Errico, F., Wesselingh, F. et al. Homo erectus at Trinil on Java used shells for tool production and engraving. Nature 518, 228-231 (2015). https://doi.org/10.1038/nature13962
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 As is usual practice in such research, Fifi is an assumed name. Fifi gave permission for data she contributed to the research to be used in publications on the assumption it would be associated with a pseudonym. (See: 'Using pseudonyms in reporting research'.)
2 No one is suggesting that the hominid deliberately marked the shell with a letter of the Roman alphabet, just that s/he deliberately made a mark that represented a definite and deliberate pattern. Yet human beings tend to spot patterns in random data. Could it just be some marks that seem to fit into a single pattern?
3 Josephine C. A. Joordens, Francesco d'Errico, Frank P. Wesselingh, Stephen Munro, John de Vos, Jakob Wallinga, Christina Ankjærgaard, Tony Reimann, Jan R. Wijbrans, Klaudia F. Kuiper, Herman J. Mücher, Hélène Coqueugniot, Vincent Prié, Ineke Joosten, Bertil van Os, Anne S. Schulp, Michel Panuel, Victoria van der Haas, Wim Lustenhouwer, John J. G. Reijmer & Wil Roebroeks.
4 At one time there was no evidence of 'noble' gases reacting. At one time there was no evidence of ozone depletion. At one time there was no evidence of superconductivity. At one time there was no evidence that the blood circulates around the body. At one time there was no evidence of any other planet having moons. At one time there was no evidence of protons being composed of even more fundamental particles. At one time there was no evidence of black holes. At one time there was no evidence that smoking tobacco was harmful. At one time there was no evidence of … [fill in your choice scientific discovery!]
