What COVID really likes

Researching viral preferences

Keith S. Taber

When I was listening to the radio news I heard a clip of the Rt. Hon. Sajid Javid MP, the U.K. Secretary of State for Health and Social Care, talking about the ongoing response to the COVID pandemic:

Health Secretary Sajid Javid talking on 12th September

"Now that we are entering Autumn and Winter, something that COVID and other viruses, you know, usually like, the prime minister this week will be getting out our plans to manage COVID over the coming few months."
Sajid Javid

So, COVID and other viruses usually like Autumn and Winter (by implication, presumably, in comparison with Spring and Summer).

This got me wondering how we (or Sajid, at least) could know what the COVID virus (i.e., SARS-CoV-2 – severe acute respiratory syndrome coronavirus 2) prefers – what the virus 'likes'. I noticed that Mr Javid offered a modal qualification to his claim: usually. It seemed 'COVID and other viruses' did not always like Autumn and Winter, but usually did.

Yet there was a potential ambiguity here depending how one parsed the claim. Was he suggesting that

[COVID and other viruses]

usually

like Autumn and Winter

COVID

[and other viruses usually]

like Autumn and Winter

This might have been clearer in a written text as either

COVID and other viruses usually like Autumn and Winter

COVID, and other viruses usually, like Autumn and Winter

The second option may seem a little awkward in its phrasing, ¹ but then not all viral diseases are more common in the Winter months, and some are considered to be due to 'Summer viruses':

"Adenovirus, human bocavirus (HBoV), parainfluenza virus (PIV), human metapneumovirus (hMPV), and rhinovirus can be detected throughout the year (all-year viruses). Seasonal patterns of PIV are type specific. Epidemics of PIV type 1 (PIV1) and PIV type 3 (PIV3) peak in the fall [Autumn] and spring-summer, respectively. The prevalence of some non-rhinovirus enteroviruses increases in summer (summer viruses)"

Moriyama, Hugentobler & Iwasaki, 2020: 86

Just a couple of days later Mr Javid was being interviewed on the radio, and he made a more limited claim:

Health Secretary Sajid Javid talking on BBC Radio 4's 'Today' programme, 15th September

"…because we know Autumn and Winter, your COVID is going to like that time of year"
Sajid Javid

So, this claim was just about the COVID virus, not viruses more generally, and that we know that COVID is going to like Autumn and Winter. No ambiguity there. But how do we know?

Coming to knowledge

Historically there have been various ways of obtaining knowledge.

Divine revelation: where God reveals the knowledge to someone, perhaps through appearing to the chosen one in a dream.
Consulting an oracle, or a prophet or some other kind of seer.
Intuiting the truth by reflecting on the nature of things using the rational power of the human intellect.
Empirical investigation of natural phenomena.

My focus in this blog is related to science, and given that we are talking about public health policy in modern Britain, I would like to think Mr Javid was basing his claim on the latter option. Of course, even empirical methods depend upon some metaphysical assumptions. For example, if one assumes the cosmos has inbuilt connections one might look for evidence in terms of sympathies or correspondences. Perhaps, if the COVID virus was observed closely and looked like a snowflake, that could (in this mindset) be taken as a sign that it liked Winter.

A **snowflake** – or is it a *virus particle*?
(Image by Gerd Altmann from Pixabay)

Sympathetic magic

This kind of correspondence, a connection indicated by appearance, was once widely accepted, so that a plant which was thought to resemble some part of the anatomy might be assumed to be an appropriate medicine for diseases or disorders associated with that part of the body.

This is a kind of magic, and might seem a 'primitive' belief to many people today, but such an idea was sensible enough in the context of a common set of underlying beliefs about the nature and purposes of the world, and the place and role of people in that world. One might expect that specific beliefs would soon die out if, for example, the plant shaped like an ear turned out to do nothing for ear ache. Yet, at a time when medical practitioners could offer little effective treatment, and being sent to a hospital was likely to reduce life expectancy, herbal remedies at least often (if not always) did no harm.

Moreover, many herbs do have medicinal properties, and something with a general systemic effect might work as topical medicine (i.e., when applied to a specific site of disease). Add to that, the human susceptibility to confirmation bias (taking more notice of, and giving more weight to, instances that meet our expectations than those which do not) and the placebo effect (where believing we are taking effective medication can sometimes in itself have beneficial effects) and the psychological support offered by spending time with an attentive practitioner with a good 'bedside' manner – and we can easily see how beliefs about treatments may survive limited definitive evidence of effectiveness.

The gold standard of experimental method

Of course, today, we have the means to test such medicines by taking a large representative sample of a population (of ear ache sufferers, or whatever), randomly dividing them into two groups, and using a double-blind (or should that be double-deaf) approach, treat them with the possible medicine or a placebo, without either the patient or the practitioner knowing who was getting which treatment. (The researchers have a way to know of course – or it would difficult to deduce anything from the results.) That is, the randomised control trial (RCT).

Now, I have been very critical of the notion that these kinds of randomised experimental designs should be automatically be seen as the preferred way of testing educational innovations (Taber, 2019) – but in situations where control of variables and 'blinding' is possible, and where randomisation can be applied to samples of well-defined populations, this does deserve to be considered the gold standard. (It is when the assumptions behind a research methodology do not apply that we should have reservations about using it as a strategy for enquiry.)

So can the RCT approach be used to find out if COVID has a preference for certain times of year? I guess this depends on our conceptual framework for the research (e.g., how do we understand what a 'like' actually is) and the theoretical perspective we adopt.

So, for example, behaviourists would suggest that it is not useful to investigate what is going on in someone's mind (perhaps some behaviorists do not even think the mind concept corresponds to anything real) so we should observe behaviours that allow us to make inferences. This has to be done with care. Someone who buys and eats lots of chocolate presumably likes chocolate, and someone who buys and listens to a lot of reggae probably likes reggae, but a person who cries regularly, or someone that stumbles around and has frequent falls, does not necessary like crying, or falling over, respectively.

A viral choice chamber

So, we might think that woodlice prefer damp conditions because we have put a large number of woodlice in choice chambers with different conditions (dry and light, dry and dark, damp and light, damp and dark) and found that there was a statistically significant excess of woodlice settling down in the damp sections of the chamber.

Of course, to infer preferences from behaviour – or even to use the term 'behaviour' – for some kinds of entity is questionable. (To think that woodlice make a choice based on what they 'like' might seem to assume a level of awareness that they perhaps lack?) In a cathode ray tube electrons subject to a magnetic field may be observed (indirectly!) to move to one side of the tube, just as woodlice might congregate in one chamber, but I am not sure I would describe this as electrons liking that part of the tube. I think it can be better explained with concepts such as electrical charge, fields, forces, and momentum.

It is difficult to see how we can do double blind trials to see which season a virus might like, as if the COVID virus really does like Winter, it must surely have a way of knowing when it is Winter (making blinding impossible). In any case, a choice chamber with different sections at different times of the year would require some kind of time portal installed between its sections.

Like electrons, but unlike woodlice, COVID viral particles do not have an active form of transport available to them. Rather, they tend to be sneezed and coughed around and then subject to the breeze, or deposited by contact with surfaces. So I am not sure that observing virus 'behaviour' helps here.

So perhaps a different methodology might be more sensible.

A viral opinion poll

A common approach to find out what people like would be a survey. Surveys can sometimes attract responses from large numbers of respondents, which may seem to give us confidence that they offer authentic accounts of widespread views. However, sample size is perhaps less important than sample representativeness. Imagine carrying out a survey of people's favourite football teams at a game at Stamford Bridge; or undertaking a survey of people's favourite bands as people queued to enter a King Crimson concert! The responses may [sic, almost certainly would] not fully reflect the wider population due to the likely bias in such samples. Would these surveys give reliable results which could be replicated if repeated at the Santiago Bernabeu or at a Marillion concert?

How do we know what 'COVID 'really likes?
(Original Images by OpenClipart-Vectors and Gordon Johnson from Pixabay)

A representative sample of vairants?

This might cause problems with the COVID-19 virus (SARS-CoV-2). What counts as a member of the population – perhaps a viable virus particle? Can we even know how big the population actually is at the time of our survey? The virus is infecting new cells, leading to new virus particles being produced all the time, just as shed particles become non-viable all the time. So we have no reliable knowledge of population numbers.

Moreover, a survey needs a representative sample: do the numbers of people in a sample of a human population reflect the wider population in relevant terms (be that age, gender, level of educational qualifications, earnings, etc.)? There are viral variants leading to COVID-19 infection – and quite a few of them. That is, SARS-CoV-2 is a class with various subgroups. The variants replicate to different extents under particular conditions, and new variants appear from time to time.

So, the population profile is changing rapidly. In recent months in the UK nearly all infections where the variant has been determined are due to the variant VOC-21APR-02 (or B.1.617.2 or Delta) but many people will be infected asymptotically or with mild symptoms and not be tested, and so this likely does not mean that VOC-21APR-02 dominates the SARS-CoV-2 population as a whole to the extent it currently dominates in investigated cases. Assuming otherwise would be like gauging public opinion from the views of those particular people who make themselves salient by attending a protest, e.g.:

"Shock finding – 98% of the population would like to abolish the nuclear arsenal,
according to a [hypothetical] survey taken at the recent Campaign for Nuclear Disarmament march"

In any case, surveys are often fairly blunt instruments as they need to present objectively the same questions to all respondents, and elicit responses in a format that can be readily classified into a discrete number of categories. This is why many questionnaires use Likert type items:

Would you say you like Autumn and Winter:

1	2	3	4	5
Always	Nearly always	Usually	Sometimes	Never

Such 'objective' measures are often considered to avoid the subjective nature of some other types of research. It may seem that responses do not need to be interpreted – but of course this assumes that the researchers and all the respondents understand language the same way (what exactly counts as Autumn and Winter? What does 'like' mean? How is 'usually' understood – 60-80% of the time, or 51-90% of the time or…). We can usually (sic) safely assume that those with strong language competence will have somewhat similar understandings of terms, but we cannot know precisely what survey participants meant by their responses or to what extent they share a meaning for 'usually'.

There are so-called 'qualitative surveys' which eschew this kind of objectivity to get more in-depth engagement with participants. They will usually use interviews where the researcher can establish rapport with respondents and ask them about their thoughts and feelings, observe non-verbal signals such as facial expressions and gestures, and use follow-up questions… However, the greater insight into individuals comes at a cost of smaller samples as these kinds of methods are more resource-intensive.

But perhaps Mr Javid does not actually mean that COVID likes Autumn and Winter?

So, how did the Department of Health & Social Care, or the Health Secretary's scientific advisors, find out that COVID (or the COVID virus) likes Autumn and Winter? The virus does not think, or feel, and it does not have preferences in the way we do. It does not perceive hot or cold, and it does not have a sense of time passing, or of the seasons.² COVID does not like or dislike anything.

Mr Javid needs to make himself clear to a broad public audience, so he has to avoid too much technical jargon. It is not easy to pitch a presentation for such an audience and be pithy, accurate, and engaging, but it is easy for someone (such as me) to be critical when not having to face this challenge. Cabinet ministers, unlike science teachers, cannot be expected to have skills in communicating complex and abstract scientific ideas in simplified and accessible forms that remain authentic to the science.

It is easy and perhaps convenient to use anthropomorphic language to talk about the virus, and this will likely make the topic seem accessible to listeners, but it is less clear what is actually meant by a virus liking a certain time of year. In teaching the use of anthropomorphic language can be engaging, but it can also come to stand in place of scientific understanding when anthropomorphic statements are simply accepted uncritically at face value. For example, if the science teacher suggests "the atom wants a full shell of electrons" then we should not be surprised that students may think this is a scientific explanation, and that atoms do want to fill their shells. (They do not of course. ³)

Of course Mr Javid's statements cannot be taken as a literal claim about what the virus likes – my point in this posting is to provoke the question of what this might be intended to mean? This is surely intended metaphorically (at least if Mr Javid had thought about his claim critically): perhaps that there is higher incidence of infection or serious illness caused by the COVID virus in the Winter. But by that logic, I guess turkeys really would vote for Christmas (or Thanksgiving) after all.

Typically, some viruses cause more infection in the Winter when people are more likely to mix indoors and when buildings and transport are not well ventilated (both factors being addressed in public health measures and advice in regard to COVID-19). Perhaps 'likes' here simply means that the conditions associated with a higher frequency/population of virus particles occur in Autumn and Winter?

A **snowflake**.
The conditions suitable for a higher frequency of snowflakes are more common in Winter.
So do snowflakes also 'like' Winter?
(Image by Gerd Altmann from Pixabay)

However, this is some way from assigning 'likes' to the virus. After all, in evolutionary terms, a virus might 'prefer', so to speak, to only be transmitted asymptomatically, as it cannot be in the virus's 'interests', so to speak, to encourage a public health response that will lead to vaccines or measures to limit the mixing of people.

If COVID could like anything (and of course it cannot), I would suggest it would like to go 'under the radar' (another metaphor) and be endemic in a population that was not concerned about it (perhaps doing so little harm it is not even noticed, such that people do not change their behaviours). It would then only 'prefer' a Season to the extent that that time of year brings conditions which allow it to go about its life cycle without attracting attention – from Mr Javid or anyone else.

Keith S. Taber, September 2021

Addendum: 1st December 2021

Déjà vu?

The health secretary was interviewed on 1st December

"…we have always known that when it gets darker, it gets colder, the virus likes that, the flu virus likes that and we should not forget that's still lurking around as well…"
Rt. Hon. Sajid Javid MP, the U.K. Secretary of State for Health and Social Care, interviewed on BBC Radio 4 Today programme, 1st December, 2021

Works cited:

Moriyama, M., Hugentobler, W. J., & Iwasaki, A. (2020). Seasonality of Respiratory Viral Infections. Annual Review of Virology, 7(1), 83-101. doi:10.1146/annurev-virology-012420-022445
Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058

Footnotes:

¹. It would also seem to be a generalisation based on the only two Winters that the COVID-19 virus had 'experienced'

². Strictly I cannot know what it is like to be a virus particle. But a lot of well-established and strongly evidenced scientific principles would be challenged if a virus particle is sentient.

³. Yet this is a VERY common alternative conceptions among school children studying chemistry: The full outer shells explanatory principle

Shortlisting for disease

False positives on screening tests can be understood in relation to job applications

Keith S. Taber

I rather liked an analogy used by Dr Kit Yates of Bath University comparing medical screening to being shortlisted for a job. The context was a Royal Institution podcast entitled: Can We Trust Maths? ¹

Ri Podcast available at https://soundcloud.com/royal-institution/maths-trust

This was a very informative discussion of aspects of statistics, and one of the questions addressed was:

How often do false positive and false negative test results occur in medical screenings?

Screening for disease

Screening programmes test apparently healthy members of the population for serious medical issues in order to catch problems at an early stage when treatment offers the best prognosis.

Screening programmes can quickly test many people…
(Image by Ahmad Ardity from Pixabay)

No tests are perfect, so tests will sometimes give misleading results – called false positives and false negatives.

a test result that is:	when an ideal perfect test would have shown positive	when an ideal perfect test would have shown negative
positive	is called a true positive	is called a false positive
negative	is called a false negative	is called a true negative

…but definitive diagnoses may require more sophisticated follow-up investigation
(Image by Michal Jarmoluk from Pixabay)

Sometimes tests can be tuned to avoid many false negatives by tolerating a higher rate of false positive (or vice versa). This is similar to what happens in statistical hypothesis testing when the choice of 'confidence level' (the p {for probability} value used as a cut-off criterion for 'statistical significance') can be chosen according to whether it is more important to avoid false positives or to avoid false negatives.

Choice of confidence level reflects a balance between admitting false positives (due to chance events) and false negatives (where real effects are not distinguished from chance events).
After, Taber, 2019, Fig. 7.

The notion of 'beyond reasonable doubt' used in criminal trials can be understood as based on the principle that it is better that some guilty perpetrators are not convicted at trial than to risk miscarriages of justice where innocent people may lose their liberty (or indeed in some jurisdictions, perhaps their lives). That is, it is better to have false negatives than false positives in criminal convictions.

In medical screening programmes, it is common to have an initial test which might give quite a few positive results (but hopefully not produce many false negatives, where a person with a disease appears to be clear according to the test), even though most of the positive results will prove to be false alarms (false positives) when followed up by a more sophisticated test that it is impractical or too expensive to use for mass screening.

The bias towards false positives built into some medical screening trials means that a person should not be too despondent at getting a positive result in the initial screen. Dr Yates worked through one example to show that based on the rates of false positives on certain screening tests, a person called for regular screenings over a number of years was actually more likely than not to get at least one positive screening result – but still unlikely to be unlucky enough to have the disease.

A teaching analogy

What I most liked was the use of an analogy to compare the logic of the screening process with a familiar everyday situation. Teaching can be seen as a process of making the unfamiliar familiar, and teachers often do this by comparing the unfamiliar they are charged with teaching about with something already familiar to the their students. That is only a starting point for supporting a developing understanding of the new concept or phenomenon, but it often is very useful in making abstract new ideas seem less threatening or inaccessible.

Read about making the unfamiliar familiar

One common way of making the unfamiliar familiar is through analogy: showing that what is new has a familiar conceptual structure – mapping onto a set of ideas already understood.

Read about teaching analogies

An 'outreaching' analogy?

Scientists charged with giving talks to a public audience as part of 'public communication' of science ('outreach') or attempts to improve 'public understanding' of science also have the job of making the unfamiliar familiar and may also use teaching analogies – as Dr Yates did here:

"I would make the analogy to screenings with a job interview. So, when a company wants to hire someone for a job, they send out an advert, and people send in their c.v.s. And the company can read those c.v.s quickly and make a shortlist. And that's a really cheap way, just as the first screen is a really cheap way of identifying people, who might be suitable for the job, people who might have breast cancer. And then for the job interview you call people in and you interview them and you throw 'assessment centres' at them, you do tests which are too expensive to do to the whole population at large to identify someone good for the job, but you can do it to this smaller population. And in the same way, with the screen we invite people in and we throw more expensive, more accurate tests at them to give them a diagnosis. And the point is, just because you would get invited to an interview for a job you had applied for, you wouldn't assume that you had got the job, right? So, in the same way, just because you get invited for further tests after a screen, you shouldn't assume you have the disease that is being screened for. You should wait and go to the follow-up test and see what that follow-up test says."
Dr Kit Yates explaining the logic of screening programmes

Based on an analogy used by Dr Kit Yates

This seemed a well-considered analogue, one that would be very accessible to most people in the audience. It is a common experience to have applied for jobs: perhaps sometimes not being shortlisted; sometimes called in for interview but not appointed; and sometimes being offered the job. ²

The explanations flowed nicely between the target concept (screening) and the analogue (shortlisting) – as can be seen in the tabulated version below.

"I would make the analogy to screenings	with a job interview.
	So, when a company wants to hire someone for a job, they send out an advert, and people send in their c.v.s.
	And the company can read those c.v.s quickly and make a shortlist.
	And that's a really cheap way,
just as the first screen is a really cheap way of identifying people,
	who might be suitable for the job,
people who might have breast cancer.
	And then for the job interview you call people in and you interview them and you throw 'assessment centres' at them, you do tests which are too expensive to do to the whole population at large to identify someone good for the job, but you can do it to this smaller population.
And in the same way, with the screen we invite people in and we throw more expensive, more accurate tests at them to give them a diagnosis.
	And the point is, just because you would get invited to an interview for a job you had applied for, you wouldn't assume that you had got the job, right?
So, in the same way, just because you get invited for further tests after a screen, you shouldn't assume you have the disease that is being screened for.
You should wait and go to the follow-up test and see what that follow-up test says."

An effective teaching analogy needs to have an analogue that is sufficiently familiar for an audience to appreciate its conceptual structure – and that structure must fit well when mapped across to the target concept. 'Medical screening is like job shortlisting' seems to work well on both these criteria.

Work cited:

Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058

Footnotes:

¹: "If you see a newspaper headline with a big, bold statistic, how do you know that you can trust it? How often do false positive and false negative test results occur in medical screenings? And how do you safely bet whether or not 2 people in any room will share a birthday?
This month we hear from Kit Yates about the maths of medicine, crime and the media, exploring real-world data from his book, 'The Maths of Life and Death'.
This talk was recorded from our theatre at the Royal Institution, on 21 January 2020." https://soundcloud.com/royal-institution/maths-trust

2. It might be suggested that this process reflects a middle class /professional/white collar employment experiences, whereas for many jobs, such as much shop or factory work, an employer is likely to employ the first apparently suitable candidate that applies, rather than using a slower and more expensive two stage process. This is so, but the situation of short-listing is still generally familiar through story lines in fiction, such as in television dramas.

Of mostly natural origin

Is your shampoo of natural, unnatural, or supernatural origin?

Keith S. Taber

It seems that some of the ingredients of a well-known brand of hair care products are not of natural origin (Image by Stefan Keller from Pixabay)

A well know brand of hair products is being advertised on television with an explicit claim that the shampoo is 94% of natural origin. Clearly there is also an implicit claim here about the other 6%! This dubious claim does not seem to be a slip of the tongue, as similar references can be found in product details on line (including the examples below). The science teacher in me knew that it was this kind of nonsense which supports common misconceptions about 'natural' being inherently good, and there being a clear distinction between materials that are 'natural', and those that are not.

Shampoos from brands other than Herbal Essences are 100% of natural origin.

The other evening I was watching television, and there was a shampoo being advertised, and although I was not paying attention I thought I heard the claim that the shampoo contained products of 94% natural origin. Had I misheard – a quick 'rewind' suggested not.

My next assumption was that this was sloppy language being used by some advertising copywriter, and that the manufacturer who commissioned the commercial simply had not noticed the slip. So I had a look on line.¹ It seems that the brand concerned, Herbal Essences, has a habit or topping up its products with material that is not of natural origin. The company claims it is using at least 90% materials of natural original in its latest products (see the examples below), and this is apparently seen as a positive point to stress in its marketing.

But this is just nonsense. If the shampoo was fabricated using 94% products of natural original, then 6% was not of natural origin. This leaves me to wonder where the rest originates. A shampoo, any shampoo, is 100% of natural origin.

Natural products chemistry

In chemistry there is a common term natural products which tends to be used for materials extracted from living organisms – one can extract vitamin C from oranges, and insulin for diabetics used to be extracted from pancreases from farm animals (although now it is produced by the activities of bacteria or yeast). In that sense salt (produced by evaporating sea water) and chalk (deriving from the shells debris from long dead sea organisms) are not natural products. But like everything else in the material world, salt and chalk are still of natural origin.

So what is a hair product which is not of natural origin, or which is only partially of natural origin? It seems there are two obvious contrasts to natural, which are 'unnatural' and 'supernatural'. Presumably the company was not suggesting it used ingredients of supernatural origin?

Do Herbal Essences employ a specialist formulation technologist to prepare the shampoo ingredients that are ***not*** of natural origin? (Image by pendleburyannette from Pixabay)

What makes something unnatural?

Assuming Herbal Essences products do not include material of supernatural origin, the other option would seem to be material of unnatural origin. But what makes a material unnatural.

At various times, in various cultural contexts, the divine right of kings, feudalism and slavery will have been seen as perfectly natural, as well the subservience of women to men. Certain sexual acts that are now widely (if not universally) considered part of the normal range of human behaviours have at various times in different societies been considered unnatural – indeed so unnatural that those found to have 'committed' them might be put to death.

Given that the question of 'what is human nature?' is not settled (didn't Immanuel Kant think this was the core task for philosophy?) the approach that is sometimes taken is to look instead to 'nature' herself (for nature is a 'she' as has long been established – in part justifying her domination and mistreatment by 'man'). If it happens in nature, then that's natural.

"The sun rises everyday but animals occasionally give birth to monsters. 'Natural is what occurs always or almost always', says Aristotle, generalizing from this experience."
Paul Feyerabend

So, by this criterion, saving lives with blood transfusions is not natural, and nor is hip replacement surgery, nor using an incubator to stop premature babies dying. However, cancer is natural. Pushing your siblings out of the nest, or pecking them to death, to get a greater share of the food your parents bring home is perfectly natural. Depositing your eggs in another creature, and paralysing it so that it acts as a defenseless (but alive, and so fresh) source of food when your offspring hatch out inside it, is natural.

"We can save you if you wish, but only by unnatural acts" (Image by Mohamed Hassan from Pixabay)

The man-made is not 'natural'

This depends upon demarcating humans as somehow outside of nature. This is difficult for a natural scientist to accept as 'ever since Darwin' (to borrow a phrase) it has been difficult to see how humans can be considered inherently distinct from the rest of the natural world, even if contingency has led to some obvious differences in terms of the development of culture. This argument then distinguishes the natural from the synthetic, the man-made.

A space rocket is not natural (in this sense) as it only exists because humans built it. Whether this is qualitatively different from technology elsewhere in nature – a badger's dam, a termite's nest, a honeycomb – rather than just a matter of a (admittedly impressive) difference of degree is an interesting question.

There are no doubt times where it is useful to distinguish between materials and objects that can be collected or extracted form 'natural' sources, and those that only exist because they have been synthesised by people – even if we do need to be wary of reading too much into the distinction. The Saturn V rocket did not exist 'in nature', and nor does a lemon coated in a wax so that it will stay 'fresh' longer – but one is the product of considerably less processing than the other. ²

Fluorine compounds (fluorides) are added to drinking water in many places to help protect teeth, but in other places the water supply already (i.e., 'naturally') contains fluoride at much higher levels – indeed, sometimes high enough to be considered a medical risk. This both reminds us that what is natural is somewhat arbitrary, and that what is considered natural is not necessarily desirable.

Natural and natural origin

The Saturn V rocket was synthetic – it was not found 'as is', growing in a swamp or being ejected from a volcano ('You Only Live Twice' style). But the materials it was made from were all of natural origin, even if some of them may have been the result of considerable processing of naturally occurring materials.

Everything you see here is of natural origin (From '*You Only Live Twice*', Eon Productions)

Any material thing in our world is of natural origin. Some materials are used much as found 'in nature', sometimes some cleaning or tidying is needed (think of natural diamonds being 'cut' to best reflect light), some purifying (separating compounds from crude oil fractions), some extracting (metal from ore), some synthesising (ammonia from hydrogen and nitrogen)… The amount of processing may vary considerably, but everything material that goes into a manufactured product is ultimately of natural origin.

So Herbal Essences products are 100% of natural origin, just as are the products of all their competitors.

A vague distinction

Webpages advertising specific Herbal Essences product lines often simply report that they are of 9n% natural origin, as in the examples below (95%, 96%, 97%). However, I found a page where it was clarified that the 90+% of natural origin included "purified water and ingredient materials derived from a natural source and subjected to limited processing".

So Herbal Essences do not use natural ditch water, or natural swamp water, or even natural sea water in their products, but rather purified water. I am pleased – as I have used Herbal Essences products, and will likely do so again, and I would rather not use dirty water when I am seeking to clean my hair.

Water – easily sourced from nature, and used in hair products (Image by mac231 from Pixabay)

So, it seems that for Herbal Essences, being of natural origin actually means, natural materials found in a suitable form to be used directly, or ("natural derived") only needing a "limited" amount of processing. Limited processing is a good thing in 'green chemistry' terms (less waste, less energy needed) but it is both a vague notion (who is to decide what makes the processing 'limited', and how does a consumer know what Herbal Essences count as limited?), and of course it is simply a quite different concept to being of natural origin.

I guess the company wanted a way of saying they were basing their products on natural products (such as plant extracts) without being misleading by implying that they could simply go and collect all the component materials and use them without needing any further processing. These materials may be pressed, steamed, or separated and purified in other ways, but are not generally the outcomes of complex synthetic processes. I can see both why that would be attractive to consumers, and why it is not easy to get across in a simple catchy term.

Yet the claim that 94% of your hair product is of natural origin, when a moment's thought should lead to the consumer realising that actually all products are of 100% natural origin, is a claim that (unlike the missing 6% of your Herbal Essences brand shampoo), does not have any substance.

a "limited" amount of processing
is both a vague notion and simply a quite different concept to
being of natural origin.

Appendix: Some examples of products that are not completely of natural origin

95% natural origin

The Herbal Essences Coconut Milk conditioner is, according to their website,

95% natural origin
73% purified water and 22% natural derived ingredients other 5% for a good usage experience & product stability.
https://herbalessences.co.uk/en-gb/products/coconut-milk/coconut-milk-shampoo/

96% natural origin

The Herbal Essences Coconut Milk conditioner is, according to their website

96% natural origin
88% purified water and 8% natural derived ingredients other 4% for a good usage experience & product stability.
https://herbalessences.co.uk/en-gb/products/coconut-milk/coconut-milk-conditioner/

96% natural origin

The Herbal Essences Bourbon & Manuka Honey shampoo, is,

96% natural origin
73% purified water and 23% natural derived ingredients other 4% for a good usage experience & product stability.
https://herbalessences.co.uk/en-gb/products/bourbon-manuka-honey/bourbon-manuka-honey-shampoo/

97% natural origin

Their Volumising White Strawberry & Sweet Mint shampoo, is

97% natural origin
84% purified water and 13% natural derived ingredients other 3% for a good usage experience & product stability.
https://herbalessences.co.uk/en-gb/products/white-strawberry-sweet-mint/white-strawberry-sweet-mint-shampoo/

At least ⁹/₁₀^ths natural origin

I learn from the company's website that

"All of our Herbal Essences bio:renew hair products have a 90% natural origin *"
https://herbalessences.co.uk/en-gb/whats-up-with-paraben-free-shampoo/

And they kindly explain that by natural origin they mean

"* includes purified water and ingredient materials derived from a natural source and subjected to limited processing"

Source cited:

Feyerabend, P. (2011) The Tyranny of Science. Cambridge: Polity Press

Footnote

¹: All quotes are from the website pages cited as accessed on 22nd August 2021.

². I note that Wikipedia suggests that

"Fruit waxing is the process of covering fruits (and, in some cases, vegetables) with artificial [sic] waxing material. Natural [sic] wax is removed first, usually by washing, followed by a coating of a biological or petroleum derived wax. Potentially allergenic proteins (peanut, soy, dairy, wheat) may be combined with shellac."

Not a great experiment…

What was wrong with The Loneliness Experiment?

Keith S. Taber

The loneliness experiment, a.k.a. The BBC Loneliness Experiment was a study publicised through the BBC (British public service broadcaster), and in particular through it's radio programme All in the Mind, ("which covers psychology, neuroscience & mental health" according to presenter, Claudia Hammond's website.)¹It was launched back in February 2018 – pre-COVD.²

"All in the Mind: The Loneliness Experiment launches the world's largest ever survey of its kind on loneliness." https://www.bbc.co.uk/programmes/b09r6fvn

Claudia Hammond describes herself as an "award-winning broadcaster, author and psychology lecturer". In particular "She is Visiting Professor of the Public Understanding of Psychology at the University of Sussex" where according to the University of Sussex "the post has been specially created for Claudia, who studied applied psychology at the University in the 1990s", so she is very well qualified for her presenting role. (I think she is very good at this role: she has a good voice for the radio and manages to balance the dual role of being expert enough to exude authority, whilst knowing how to ask necessarily naive questions of guests on behalf of non-specialist listeners.)

A serious research project

The study was a funded project based on a collaboration between academics from a number of universities, led by Prof Pamela Qualter, Professor of Education at the Manchester Institute of Education at the University of Manchester. Moreoever, "55,000 people from around the world chose to take part in the BBC Loneliness Experiment, making it the world's largest ever study on loneliness" (https://claudiahammond.com/bbc-loneliness-experiment/)

Loneliness is a serious matter that affects many people, and is not be made light of. So this was a serious study, on an important topic – yet every time I heard this mentioned on the radio (and it was publicised a good deal at the time) I felt myself mentally (and sometimes physically) cringe. Even without hearing precise details of the research design, I could tell this was simply not a good experiment.

This was not due to any great insight on my behalf, but was obvious from the way the work was being described. Readers may wish to see if they can spot for themselves what so irked me.

What is the problem with this research design?

This is how the BBC described the study at its launch:

The Loneliness Experiment, devised by Professor Pamela Qualter and colleagues, aims to look at causes and possible solutions to loneliness. And we want as many people as possible to fill in our survey, even if they've never felt lonely, because we want to know what stops people feeling lonely, so that more of us can feel connected.
https://www.bbc.co.uk/programmes/b09r6fvn

This is how Prof. Hammond described the research in retrospect:

55,000 people from around the world chose to take part in the BBC Loneliness Experiment, making it the world's largest ever study on loneliness. Researchers from the universities of Manchester, Brunel and Exeter, led by Professor Pamela Qualter and funded by the Wellcome Trust, developed a questionnaire asking people what they thought loneliness was, when they felt lonely and for how long.
https://claudiahammond.com/bbc-loneliness-experiment/

And this is how the work is described on the University of Manchester's pages:

The Loneliness Experiment was a study conducted by BBC Radio 4's All in the Mind….
The study asked respondents to give their opinions and record their experiences of loneliness and related topics, including friendship, relationships, and the use of technology – as well as recording lifestyle and background information. Respondents also engaged in a number of experiments.
The survey was developed by Professor Pamela Qualter, from The University of Manchester's Manchester Institute of Education (MIE), with colleagues from Brunel University London, and the University of Exeter. The work was funded by a grant from The Wellcome Trust.
https://www.seed.manchester.ac.uk/education/research/impact/bbc-loneliness-experiment/

When is an experiment not an experiment?

These descriptions make it obvious that the The Loneliness Experiment was not an experiment. Experiment is a specific kind of research – a methodology where the researchers randomly assign participants randomly to conditions, intervene in the experimental condition,and take measurements to see what effect the intervention has by comparing with measurements in a control condition. True experiments are extremely difficult to do in the social sciences (Taber, 2019), and often quasi-experiments or natural experiments are used which do not meet all the expectations for true experiments. BUT, to be an experiment there has to be something that can be measured as changing over time in relation to specified different conditions.

Experiment involves intervention (Image by Gerd Altmann from Pixabay)

Experiment is not the only methodology used in research – there are also case studies, there is action research and grounded theory, for example – and non-experimental research may be entirely appropriate in certain situations, and can be of very high quality. One alternative methodology is the survey which collects data form a sample of a population at some particular time. Although surveys can be carried out in various ways (for example, through a series of observations), especially common in social science is the survey (a methodology) carried out by using participant self-responses to a questionnaire (a research instrument).

it is clear from the descriptions given by the BBC, Professor Hammond and the University of Manchester that the The Loneliness Experiment was not actually an experiment at all, but basically a survey (even if, tantalisingly, the Manchester website suggests that "Respondents also [sic] engaged in a number of experiments". )

The answer to the question 'when is an experiment not an experiment?' might simply be: when it is something other than an experiment

Completing a questionnaire (Image by Andreas Breitling from Pixabay)

What's in a name: does it really matter?

Okay, so I am being pedantic again.

But I do think this matters.

I think it is safe to assume that Prof. Hammond, Prof. Qualter and colleagues know the difference between an experiment and a survey. Presumably someone decided that labelling the research as the loneliness study or the loneliness survey would not be accessible (or perhaps not as impressive) to a general audience and so decided to incorrectly use the label experiment as if experiment was synonymous with study/research.

As a former research methods lecturer, that clearly irks as part of my job was to teach new researchers about key research concepts. But I would hope that people actually doing research or learning to do research are not going to be confused by this mislabelling.

But, as a former school science teacher, I know that there is widespread public misunderstanding of key nature of science terms such as theory and experiment. School age students do need to learn what is meant by the word experiment, and what counts as an experiment, and the BBC is being unhelpful in presenting research that is not experimental as an experiment – as this will simply reinforce common misconceptions of what the term experiment is actually used to denote in research .

So, in summary, I'll score The BBC Loneliness Experiment

motivation – excellent;
reach – impressive;
presentation – unfortunate and misleading

Work cited:

Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058 [Download manuscript version]

Note:

1: Websites cited accessed on 28th August, 2021.

2: It would have been interesting to repeat when so many people around the world were in 'lock-down'. (A comparison between pre-COVID and pandemic conditions might have offered something of a natural experiment.)

Shock! A typical honey bee colony comprises only six chemicals!

Is it half a dozen of one, or six of the other?

Keith S. Taber

Bee-ware chemicals!
(Images by PollyDot and Clker-Free-Vector-Images from Pixabay)

A recent episode of the BBC Inside science radio programme and podcast was entitled 'Bees and multiple pesticide exposure'. This discussed a very important issue that I have no wish to make light of. Researchers were looking at the stressors which might be harming honey bees, very important pollinators for many plants, and concluded that these likely act synergistically. That is a colony suffering from, say a drought and at the same time a mite infection, will show more damage that one would expect from simply adding the typical harm of each as if independent effects. Rather there are interactions.

This is hardly surprising, but is none-the-less a worrying finding.

Bees and multiple pesticide exposure episode of BBC Inside Science

However, my 'science teacher' radar honed in on an aspect of the language used to explain the research. The researcher interviewed was Dr Harry Siviter of the University of Texas at Austin. As part of his presentation he suggested that…

"Exposure to multiple pesticides is the norm, not the exception. So, for example a study in North America showed that the average number of chemicals found in a honey bee colony is six, with a high of 42. So, we know that bees are exposed to multiple chemicals…"
Dr Harry Siviter

The phrase that stood out for me was "the average number of chemicals found in a honey bee colony is six" as clearly that did not make any sense scientifically. At least, not if the term 'chemical' was meant to refer to 'chemical substance'. I cannot claim to know just how many different substances would be found if one analysed honey bee colonies, but I am pretty confident the average would be orders of magnitude greater than six. An organism such as a bee (leaving aside for a moment the hive in which it lives) will be, chemically, 'made up' of a great many different proteins, amino acids, lipids, sugars, nuclei acids, and so forth.

"the average number of chemicals found in a honey bee colony is six"

From the context, I understood that Dr Siviter was not really talking about chemicals in general, but pesticides. So, I am (not for the first time) being a pedant in pointing out that technically he was wrong to suggest "the average number of chemicals found in a honey bee colony is six" as any suitably informed listener would have immediately, and unproblematically, understood what he meant by 'chemicals' in this context.

Yet, as a teacher, my instinct is to consider that programmes such as this, designed to inform the public about science, are not only heard by those who are already well-versed in the sciences. By its nature, BBC Inside Science is intended to engage with a broad audience, and has a role in educating the public about science. I also knew that this particular pedantic point linked to a genuine issue in science teaching.

A common alternative conception

The term chemical is not usually used in science discourse as such, but rather the term substance. Chemical substances are ubiquitous, although in most everyday contexts we do not come across many pure samples of single substances. Tap water is nearly all water, and table salt is usually about 99% sodium chloride, and sometimes metals such as copper or aluminium are used in more or less pure form. But these tend to be exceptions – most material entities we engage with are not pure substances ('chemicals'), rather being mixtures or even more complex (e.g., wood or carrot or hair).

In everyday life, the term chemical tends to be used more loosely – so, for example, household bleach may be considered 'a chemical'. More problematically 'chemicals' tends to be seen as hazardous, and often even poisonous. So, people object to there being 'chemicals' in their food – when of course their food comprises chemicals and we eat food to access those chemicals because we are also made up of a great many chemicals. Food with the chemicals removed is not food, or indeed, anything at all!

In everyday discourse 'chemical' is often associated with 'dangerous' (Image by Arek Socha from Pixabay)

So, science teachers not only have the problem that in everyday discourse the term 'chemical' does not map unproblematically on 'substance' (as it is often used also for mixtures), but even more seriously that chemicals are assumed to be bad, harmful, undesirable – something to be avoided and excluded. By contrast, the scientific perspective is that whilst some chemicals are potentially very harmful, others are essential for life. Therefore, it is unhelpful when science communicators (whether journalists, or scientists themselves) use the term 'chemical' to refer only to potentially undesirable chemicals (which even then tend to be undesirable only in certain contexts), such as pesticides which are found in, and may harm, pollinators.

I decided to dig into the background of the item.

The news item

I found a news item in 'the Conversation' that discuses the work.

Dr Siviter's Article in the Conversation

It began

"A doctor will always ask if you are on any other medication before they write you a prescription. This is because pharmaceuticals can interact with each other and potentially disrupt the treatment, or even harm the patient. But when agrochemicals, such as pesticides, are licensed for use on farms, little attention is paid to how they interact with one another, and so their environmental impact is underestimated."
Siviter, 2021

This seemed a very good point, made with an analogy that seemed very telling.

(Read about science analogies)

This was important because:

"We analysed data gathered in scientific studies from the last two decades and found that when bees are exposed to a combination of pesticides, parasites and poor nutrition, the negative impact of each is exacerbated. We say that the cumulative effect of all these things is synergistic, meaning that the number of bees that are killed is more than we would predict if the negative effects were merely added together."
Siviter, 2021

This seems important work, and raises an issue we should be concerned about. The language used here was subtly different from in the radio programme:

"Many agrochemicals, such as neonicotinoids, are systemic, meaning they accumulate in the environment over several months, and in some cases years. It is perhaps not surprising then that honeybee colonies across the US have on average six different agrochemicals present in their wax, with one hive contaminated with 39 [sic, not 42]. It's not just honeybees which are at risk, though: wild bees such as bumblebees are also routinely exposed."
Siviter, 2021

So, here it was not 'chemicals' that were being counted but 'agrochemicals' (and the average figure of 6 now referred not to the colony as a whole, but only to the beeswax.)

The meta-analysis

'Agrochemicals' was also the term used in the research paper in the prestigious journal Nature where the research had been first reported,

"we conducted a meta-analysis of 356 interaction effect sizes from 90 studies in which bees were exposed to combinations of agrochemicals, nutritional stressors and/or parasites."
Siviter, et al., 2021

A meta-analysis is a type of secondary research study which collects results form a range of related published studies and seeks to identify overall patterns.

The original research

Moreover, the primary study being referred to as the source of the dubious statistic (i.e., that "the average number of chemicals found in a honey bee colony is six") referred not to 'chemicals' but to "pesticides and metabolites" (that is, substances which would be produced as the bee's metabolism broke the pesticides down):

"We have found 121 different pesticides and metabolites within 887 wax, pollen, bee and associated hive samples….
Almost all comb and foundation wax samples (98%) were contaminated with up to 204 and 94 ppm [parts per million], respectively, of fluvalinate and coumaphos, and lower amounts of amitraz degradates and chlorothalonil, with an average of 6 pesticide detections per sample and a high of 39."
Mullin, et al., 2010

Translation and representation

Scientific research is reported in research journals primarily for the benefit of other researchers in the field, and so is formatted and framed accordingly – and this is reflected in the language used in primary sources.

A model of the flow of scientific to public knowledge (after McInerney et al., 2004)

Fig. 10.2 from Taber, 2013

It is important that science which impacts on us all, and is often funded from public funds, is accessible to the public. Science journalism, is an important conduit for the communication of science, and for his to be effective it has to be composed with non-experts in the public in mind.

(Read about science in public discourse and the media)

It is perfectly sensible and desirable for a scientist engaging with a public audience to moderate technical language to make the account of research more accessible for a non-specialist audience. This kind of simplification is also a core process in developing science curriculum and teaching.

(Read about representing science in the curriculum)

However, in the case of 'chemical' I would suggest scientists take care with using the term (and avoid it if possible), as science teachers commonly have to persuade students that chemicals are all around of us, are not always bad for us, are part of us, and are essential. That pesticides and their breakdown products have been so widely detected in bee colonies is a matter of concern, as pesticides are substances that are used because of their detrimental effects on many insects and other organisms that might damage crops.

Whilst that is science deserving public attention, there are a good many more than 6 chemicals in any bee colony, and – indeed – we would want most of them to be there.

References:

McInerney, C., Bird, N., & Nucci, M. (2004). The Flow of Scientific Knowledge from Lab to the Lay Public: The Case of Genetically Modified Food. Science Communication, 26(1), 44-74. doi:10.1177/1075547004267024 https://journals.sagepub.com/doi/10.1177/1075547004267024
Mullin, C. A., Frazier, M., Frazier, J. L., Ashcraft, S., Simonds, R., vanEngelsdorp, D., & Pettis, J. S. (2010). High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health. 5(3): e9754. PLoS ONE, 5(3), e9754. doi:10.1371/journal.pone.0009754 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0009754
Siviter, H. (2021) Pesticides: interactions between agrochemicals increase their harm to bees, The Conversation, August 4, 2021 5.36pm BST, https://theconversation.com/pesticides-interactions-between-agrochemicals-increase-their-harm-to-bees-165626
Siviter, H., Bailes, E. J., Martin, C. D., Oliver, T. R., Koricheva, J., Leadbeater, E., & Brown, M. J. F. (2021). Agrochemicals interact synergistically to increase bee mortality. Nature. doi:10.1038/s41586-021-03787-7 https://www.nature.com/articles/s41586-021-03787-7
Taber, K. S. (2013). Modelling Learners and Learning in Science Education: Developing representations of concepts, conceptual structure and conceptual change to inform teaching and research. Dordrecht: Springer.

Resowing the garden in your gut

A faecal transplant is like wild flower seeds in some soil

Keith S. Taber

"Many animals naturally ate each other's poo…as a way of staying healthy" Prof. Tim Spector. (Original image by Debbie De Jager from Pixabay, with apologies to Monty Python)

I was listening to a podcast from 'Science Stories' (BBC Radio 4) about 'Lady Mary Montagu's Smallpox Experiment', where Naomi Alderman described how the aforementioned Lady Mary Wortley Montagu brought the practice of opening veins to introduce some smallpox into the body, as a way of protecting against the deadly disease, back from Turkey to Britain.

An episode in the BBC Radio 4 series '*Science Stories*'

Flush or donate?

This was compared with the process of faecal transplantation which was apparently first used in China, and is increasingly being seen as a valuable treatment for some gut disorders. This is the process of ingesting, under carefully controlled conditions, some human faeces – either some of your own carefully preserved (for example, some cancer patients have a sample collected and stored before starting chemotherapy), or from some donor who is willing to offer some of their own. Unlike some other donor procedures (such as kidney donation) this is non-invasive and concerns material most of us just dispose of anyway!

Tim Spector, Professor of Genetic Epidemiology at Kings College, London explained the significance of the gut microbiome, the community of something like 100 trillion microbes that typically occupy a human gut. The importance of these organisms for human health is increasingly being appreciated.

Treating Clostridium difficile infection

Disturbances of the gut microbiome can lead to ill health. One particular example is the condition known as Clostridium difficile infection ('C. diff') – which is commonly experienced in hospitals when patients have extensive courses of antiobiotics – which can sadly kill the useful gut microbes as well those disease-causing organisms being targeted. Clostridium difficile (being itself unaffected by many commonly used antibiotics) can in these circumstances reproduce rapidly and vastly increase its numbers. This is problematic as the organism releases a toxin.

C. diff infection can lead to the sufferer needing to visit the toilet urgently and repeatedly – many times each day. This is not only undesirable in itself, but interferes with getting nutrition from food (if the person has any appetite to eat), and leads to dangerous dehydration – and can have other complications. So, this is a very serious condition, and it is readily transmitted from one person to another.

"C. difficile is an infectious Gram-positive spore-forming bacillus microorganism of the gastrointestinal tract, and its toxin expression causes gastrointestinal illness with a wide spectrum of severity, ranging from mild diarrhea to pseudomembranous colitis, toxic megacolon, sepsis-like picture and death…"
Bien, Palagan & Bozko, 2013: 53

Many people have a low level of Clostridium difficile specimens in their gut normally, but as one small part of the much larger and diverse population of gut microbes – in which context they cause no problems.

"C. difficile does not cause any significant disease when it is present in small numbers. However, disturbance of the normal intestinal flora (dysbiosis) by several potential causative factors may result in unlimited [sic] expansion of C. difficile in the microbiota, leading to inflammation and damage of the gut mucosa…"
Bien, Palagan & Bozko, 2013: 56

Someone who has suffered from C. diff infection needs a way to repopulate their gut with a good range of the usual different microbes. And that is when consuming a sample of a healthy person's excrement can be useful. (This is of course done under medical direction and supervision, both to maintain hygiene and to ensure the donor does not have medical conditions that might be passed on with the sample.)

A teaching analogy for faecal transplantation

This was all explained by Prof. Spector using an analogy.

Analogies are comparisons where a less familiar, and perhaps abstract or counterintuitive, concept is explained in terms of something familiar that can be seen to have a similar conceptual structure (see the figure). Analogies are commonly used in science teaching and public communication of science (as here in a radio programme) to introduce scientific ideas.

(Read about science analogies)

Figure: A teaching analogy to explain why faecal transplantation can be used to treat C. diff (based on the presentation by Prof. Tim Spector in '*Lady Mary Montagu's Smallpox Experiment*')

How does your garden grow?

Prof. Spector developed a comparison between the different microbes found in the gut, and the plants growing in a garden:

"These nasty infections are the most extreme, if you like, that pretty much wipe out most of our normal species. So … we might, say, start with a thousand species and people [with C. diff] might be down to just ten or so, different ones and so nasty ones take over. It's a bit like a garden that has gone very badly wrong and you have put too much herbicide all over it and it looks like an Arizona back yard with a few burning tyres in it. It's very easy for things to take over that and what we want to get, is by putting these bugs in there, to create a really healthy garden that gets back to normal that looks like a nice English country garden with lots of blooms, and really good soil, and lots of plants interacting with each other, and that's the way to think about these microbes, but to do that, to get to this nice rosy picture of a country garden you have to go through yucky stages first"
Prof. Tim Spector – From 'Lady Mary Montagu's Smallpox Experiment'

Before and after faecal transplantation: a medical treatment that can transform your 'garden'? (Images by Simon (left) and Prawny (right) from Pixabay)
[Move the slider to change between the pictures].

So the idea of taking a sample of someone else's excrement into our own gut may seem "yukky" – and is definitely NOT recommended without proper procedures and supervision – but may sometimes be a sensible and beneficial medical treatment. Just think of it as resewing the garden of the gut with a nice selection of seeds that will give rise to a diverse selection of colourful blooms.

Naomi Alderman: Instead of poo, we could think to ourselves, 'wild flower seeds'

Tim Spector: It's wild flower seeds with a bit of soil in it as well, so they have come in their own pot [sic] if you like.
From 'Lady Mary Montagu's Smallpox Experiment'

'wild flower seeds with a bit of soil…in their own pot'? (Images by OpenClipart-Vectors from Pixabay)

Work cited:

Bien, J., Palagani, V., & Bozko, P. (2013). The intestinal microbiota dysbiosis and Clostridium difficile infection: is there a relationship with inflammatory bowel disease? Therapeutic advances in gastroenterology, 6(1), 53-68. doi:10.1177/1756283X12454590 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3539291/

Balding black holes – a shaggy dog story

Resurrecting an analogy from a dead metaphor?

Keith S. Taber

Now there's a look in your eyes, like black holes in the sky…(Image by Garik Barseghyan from Pixabay)

I was intrigued by an analogy in a tweet

Like a shaggy dog in springtime, some black holes have to shed their "hair."

The link led me to an item at a webpage at 'Science News' entitled 'Black holes born with magnetic fields quickly shed them' written by Emily Conover. This, in turn, referred to an article in Physical Review Letters.

Now Physical Review Letters is a high status, peer-reviewed, journal.

(Read about peer review)

As part of the primary scientific literature, it publishes articles written by specialist scientists in a technical language intended to be understood by other specialists. Dense scientific terminology is not used to deliberately exclude general readers (as sometimes suggested), but is necessary for scientists to make a convincing case for new knowledge claims that seem persuasive to other specialists. This requires being precise, using unambiguous technical language."The thingamajig kind of, er, attaches to the erm, floppy bit, sort of" would not do the job.

(Read about research writing)

Science News however is news media – it publishes journalism (indeed, 'since 1921' the site reports – although that's the publication and not its website of course.) While science journalism is not essential to the internal processes of science (which rely on researchers engaging with each other's work though scholarly critique and dialogue) it is very important for the public's engagement with science, and for the accountability of researchers to the wider community.

Science journalists have a job similar to science teachers – to communicate abstract ideas in a way that makes sense to their audience. So, they need to interpret research and explain it in ways that non-specialists can understand.

The news article told me

"Like a shaggy dog in springtime, some black holes have to shed…
Unlike dogs with their varied fur coats, isolated black holes are mostly identical. They are characterized by only their mass, spin and electric charge. According to a rule known as the no-hair theorem, any other distinguishing characteristics, or "hair," are quickly cast off. That includes magnetic fields."

Conover, 2013

Here there is clearly the use of an analogy – as a black hole is not the kind of thing that has actual hair. This would seem to be an example of a journalist creating an analogy (just as a science teacher would) to help 'make the unfamiliar familiar' to her readers:

just as

dogs with lots of hair need to shed some ready for the warmer weather (a reference to a familiar everyday situation)

so, too, do

black holes (no so familiar to most people) need to lose their hair…

(Read about making the unfamiliar familiar)

But hair?

Surely a better analogy would be along the lines that just as dogs with lots of hair need to shed some ready for the warmer weather, so to do black holes need to lose their magnetic fields…

An analogy is used to show a novel conceptual structure (here, relating to magnetic fields around black holes) maps onto a more familiar, or more readily appreciated, one (here, that a shaggy dog will shed some of its fur). A teaching analogy may not reflect a deep parallel between two systems, as its function may be just to *introduce* an abstract principle.

(Read about science analogies)

Why talk of black holes having 'hair'?

Conover did not invent the 'hair' reference for her ScienceNews piece – rather she built her analogy on a term used by the scientists themselves. Indeed, the title of the cited research journal article was "Magnetic Hair and Reconnection in Black Hole Magnetospheres", and it was a study exploring the consequences of the "no-hair theorem" – as the authors explained in their abstract:

"The no-hair theorem of general relativity states that isolated black holes are characterized [completely described] by three parameters: mass, spin, and charge."

Bransgrove, Ripperda & Philippov, 2021

However, some black holes "are born with magnetic fields" or may "acquire magnetic flux later in life", in which case the fields will vary between black holes (giving an additional parameter for distinguishing them). The theory suggests that these black holes should somehow lose any such field: that is, "The fate of the magnetic flux (hair) on the event horizon should be in accordance with the no-hair theorem of general relativity" (Bransgrove, Ripperda & Philippov, 2021: 1). There would have to be a mechanism by which this occurs (as energy will be conserved, even when dealing with black holes).

So, the study was designed to explore whether such black holes would indeed lose their 'hair'. Despite the use of this accessible comparison (magnetic flux as 'hair'), the text of the paper is pretty heavy going for someone not familiar with that area of science:

"stationary, asymptotically flat BH spacetimes…multipole component l of a magnetic field…self-regulated plasma…electron-positron discharges…nonzero stress-energy tensor…instability…plasmoids…reconnection layer…relativistic velocities…highly magnetized collisionless plasma…Lundquist number regime…Kerr-schild coordinates…dimensionless BH spin…ergosphere volume…spatial hypersurfaces…[…and so it continues]"

(Bransgrove, Ripperda & Philippov, 2021: 1).

"***Come on Harry, you know full well that 'the characteristic minimum plasma density required to support the rotating magnetosphere is the Goldreich-Julian number density'*** *[Bransgrove, Ripperda & Philippov, 2021: 2]****, so hand me that hyperspanner***."
Image from Star Trek: Voyager (Paramount Pictures)

Spoiler alert

I do not think I will spoil anything by revealing that Bransgrove and colleague conclude from their work that "the no-hair theorem holds": that there is a 'balding process' – the magnetic field decays ("all components of the stress-energy tensor decay exponentially in time"). If any one reading this is wondering how they did this work, given that most laboratory stores do not keep black holes in stock to issue to researchers on request, it is worth noting the study was based on a computer simulation.

That may seem to be rather underwhelming as the researchers are just reporting what happens in a computer model, but a lot of cutting-edge science is done that way. Moreover, their simulations produced predictions of how the collapsing magnetic fields of real black holes might actually be detected in terms of the kinds of radiation that should be produced.

As the news item explained matters:

Magnetic reconnection in balding black holes could spew X-rays that astronomers could detect. So scientists may one day glimpse a black hole losing its hair.

Conover, 2013

So, we have hairy black holes that go through a balding process when they lose their hair – which can be tested in principle because they will be spewing radiation.

Balding is to hair, as…

Here we have an example of an analogy for a scientific concept. Analogies compare one phenomenon or concept to another which is considered to have some structural similarity (as in the figure above). When used in teaching and science communication such analogies offer one way to make the unfamiliar familiar, by showing how the unfamiliar system maps in some sense onto a more familiar one.

hair = magnetic field

balding = shedding the magnetic field

Black holes are expected to be, or at least to become, 'hairless' – so without having magnetic fields detectable from outside the event horizon (the 'surface' connecting points beyond which everything, even light, is unable to 'escape' the gravitational field and leave the black hole). If black holes are formed with, or acquire, such magnetic fields, then there is expected to be a 'balding' process. This study explored how this might work in certain types of (simulated) black holes – as magnetic field lines (that initially cross the event horizon) break apart and reconnect. (Note that in this description the magnetic field lines – imaginary lines invented by Michael Faraday as a mental tool to think about and visualise magnetic fields – are treated as though they are real objects!)

Some such comparisons are deliberately intended to help scientists explain their ideas to the public – but scientists also use such tactics to communicate to each other (sometimes in frivolous or humorous ways) and in these cases such expressions may do useful work as short-hand expressions.

So, in this context hair denotes anything that can be detected and measured from outside a black hole apart form its mass, spin, and charge (see, it is much easier to say 'hair')- such as magnetic flux density if there is a magnetic field emerging from the black hole.

A dead metaphor?

In the research paper, Bransgrove, Ripperda and Philippov do not use the 'hair' comparison as an analogy to explain ideas about black holes. Rather they take the already well-established no-hair theorem as given background to their study ("The original no-hair conjecture states that…"), and simply explain their work in relation to it ("The fate of the magnetic flux (hair) on the event horizon should be in accordance with the no-hair theorem of general relativity.")

Whereas an analogy uses an explicit comparison (this is like that because…), a comparison that is not explained is best seen as a metaphor. A metaphor has 'hidden meaning'. Unlike in an analogy, the meaning is only implied.

"The no-hair theorem of general relativity states that isolated black holes are characterized by three parameters: mass, spin, and charge";
"The original no-hair conjecture states that all stationary, asymptotically flat BH [black hole] spacetimes should be completely described by the mass, angular momentum, and electric charge"

(Read adbout science metaphors)

Bransgrove and colleagues do not need to explain why they use the term 'hair' in their research report as in their community it has become an accepted expression where researchers already know what it is intended to mean. We might consider it a dead metaphor, an expression which was originally used to imply meaning through some kind of comparison, but which through habitual use has taken on literal meaning.

Science has lots of these dead metaphors – terms like electrical charge and electron spin have with repeated use over time earned their meanings without now needing recourse to their origins as metaphors. This can cause confusion as, for example, a learner may develop alternative conceptions about electron spin if they do not appreciate its origin as a metaphor, and assumes an electron spins in the same sense as as spinning top or the earth in space. Then there is an associative learning impediment as the learner assumes an electron is spinning on its axis because of the learner's (perfectly reasonable) associations for the word 'spin'.

The journalist or 'science writer' (such as Emily Conover), however, is writing for a non-specialist readership, so does need to explain the 'hair' reference. So, I would characterise the same use of the terms hair/no-hair and balding as comprising a science analogy in the news item, but a dead metaphor in the context of the research paper. The meaning of language, after all, is in the mind of the reader.

Work cited:

Bransgrove, A., Ripperda, B., & Philippov, A. (2021). Magnetic Hair and Reconnection in Black Hole Magnetospheres. Physical Review Letters, 127(5), 055101. doi:10.1103/PhysRevLett.127.055101 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.055101
Conover, E. (2013, August 3rd 2021). Black holes born with magnetic fields quickly shed them. ScienceNews. https://www.sciencenews.org/article/black-hole-magnetic-field-hair-computer-simulations-physics

"…bacteria are just tiny eyeballs…"

Keith S. Taber

The unbelievable truth – do bacteria focus incident light onto their back-sides, so they can tell which way to go?

"Bacteria are just tiny eyeballs" sounds like another science analogy, but is actually something I learned today from BBC Radio 4.

On David Mitchell's "The Unbelievable Truth" panelists read essays on a topic, but populated with false (and preferably funny) statements. The premise is great: the panelists try to sneak in some true facts which sound so unlikely that they are confused with the falsehoods. Panelists get marks for correctly spotting truths in another panelist's little essay, or for completing their own talk with some of their 'unbelievable' truths not being spotted.

On today's episode I was shocked top learn from Dr Ria Lina that "…bacteria are just tiny eyeballs…".

Because they are not.

Well, not exactly…

Her essay was talking about germs, and included:

"Transmission of disease is determined by how many victims germs can actually see. Viruses have load of tiny little eyes so they are able to see loads and loads of potential victims in all different directions, whereas bacteria are just tiny little eyeballs, and fungi are extremely short sighted poor things, which is why they are only able to infect places like feet."

At the end of the round, David reported that the part about bacteria as eyes was true, although he did not seem very convinced:

David: You have managed to smuggle three truth past the rest of the panel, which are that bacteria are just tiny eyeballs – although to me that sounds a bit like things being put into language that people understand, because they are not like tiny eyeballs, really are they?

Ria: Well the light goes in and it reflects off the back surface which acts like a rudimentary retina…

Right,

…and also you have got to remember that the eye had evolved multiple times in multiple ways, so the squid eye and the human eye even though they both work the same way did not come from the same universal ancestor…

Oh right

…so, bacterial eye is basically what we are seeing now is the beginning of – [sadly interrupted by another panelist]. I'm such a geek…

Ria Lina – self-confessed geek (and there is nothing wrong with that)

I presumed there must be some basis for this claim; that Dr Lina (PhD in viral bioinformatics) must be drawing upon some actual science, but I was not sure what. Whereas the eyeball has a back surface there is no inherent back surface for a bacterium – so this must mean any inside surface.

Although light does reflect off the retina (red eye in camera images is due to the light reflecting from the retina with its rich supply of blood vessels) – the function of the retina is to absorb light and to then signal information forward based on the pattern of light detected. Some species have a reflecting layer (tapetum lucidum) behind the retina to increase efficiency – some light not absorbed by the retina initially gets a second pass though after reflection which allows increased absorption. But this is only useful because there are cells capable of absorbing the light and processing information based on the absorption.

The bacterium is a single cell, so the most sense I could make of this is that when light absorption is useful, a reflecting inner surface could be valuable. This might make sense for cyanobacteria to increase the efficiency of photosynthesis by reflecting light not absorbed on the first pass.

What did we do before the internet?

I did some quick searching on line.

Someone had developed a method of identifying bacterial colonies through light back-scattered, which was useful because the technique using transmitted light was impractical in species that absorb most of the incident light.

Interesting, but the light was not being reflected internally, if I understood the paper.

Someone has developed a technique to increase the light absorbed by photosynthetic algae and cyanobacteria that did use total internal reflection – but if I read correctly this reflection is in the light guide on the way to the cell, not inside it.

So, I was still not buying the eyeballs story. Then I found a report of how "Cyanobacteria use micro-optics to sense light direction",

"Here, we establish that individual Synechocystis cells can directly and accurately perceive the position of a unidirectional light source, and control their motility so as to move towards it. We then show that Synechocystis cells act as microlenses, and that the light intensity gradient across the cell due to this lensing effect is far greater than the effects of shading due to light absorption or reflection. Finally, we use highly-localized laser excitation to show that specific excitation of one side of the cell triggers movement away from the light, indicating that positive phototaxis results from movement away from an image of the light source focused on the opposite side of the cell. Essentially, the cell acts as a microscopic eyeball."

Schuergers et al.,2016

Wow, nature never ceases to amaze.

So, basically the cell itself focuses incident light to be concentrated at the 'back' of the cell (where back is the side opposite the light source), organelles that absorb light can in effect detect this light 'spot', and the bacterium has evolved to move 'forward' towards the light source based on where in the cell this higher light intensity occurs. The system in effect 'knows' which direction to take as forward.

"Here we have shown that Synechocystis cells act as very effective spherical microlenses that focus a sharp image of a light source at the opposite edge of the cell. This implies that positive phototaxis (i.e. movement towards a light source) is actually triggered as a negative response to the focused spot of light at rear periphery of the cell."

Schuergers et al.,2016

This does not seem to involve internal reflection, so perhaps there is another source for the eyeballs claim (possibly with an even more amazing nugget of science) that I have missed and which was the basis of Dr Lina's claim.

Bacteria are not just tiny eyeballs, but…

I still think it is not correct to claim that "bacteria [generally, or even this particular bacteria] are just tiny eyeballs". This is a simplification, and probably not an 'intellectually honest' one that could be considered to be at the 'optimum level of simplification' for communicating a key scientific idea stripped of distracting complications.

(read about the the optimum level of simplification – a key idea in teaching)

Indeed the real wonder of Synechocystis is that it a single cell that acts as an integrated, responsive, coherent system: energy collection unit, eyeball, lens, photo-receptors, controller/processor, and locomotive unit.

Despite this quibble, given the context of the claim (made as part of a comedy show, not a peer reviewed research conference) I think I am impressed enough to have to revise the 'Tweet' I was going to send Dr Lina calling her out for telling an unbelievable lie on national radio. I should have remembered that it is very difficult to come up with any claim about the living world which is so fantastic that one can be confident there is not an example of a species out there which affirms the claim. When it comes to nature we often need to believe the unbelievable truth.

Work cited:

Huisung Kim, Iyll-Joon Doh, Jennifer Sturgis, Arun K. Bhunia, J. Paul Robinson, Euiwon Bae (2016) Reflected scatterometry for noninvasive interrogation of bacterial colonies, Journal of Biomedical Optics. 21(10), 107004, doi: 10.1117/1.JBO.21.10.107004.
Ooms, M. D., Sieben, V. J., Pierobon, S. C., Jung, E. E., Kalontarov, M., Erickson, D., & Sinton, D. (2012). Evanescent photosynthesis: exciting cyanobacteria in a surface-confined light field. Physical Chemistry Chemical Physics, 14(14), 4817-4823. doi:10.1039/C2CP40271H
Schuergers, N., Lenn, T., Kampmann, R., Meissner, M. V., Esteves, T., Temerinac-Ott, M., . . . Wilde, A. (2016). Cyanobacteria use micro-optics to sense light direction. Elife, 5, e12620.

Elements as chemical seasoning?

Keith S. Taber

An analogy for the importance of trace elements

Unseen minerals all around us (Ockham's Razor – ABC)

I was listening to a recent episode of 'Ockhams' razor' (ABC's series of short science and technology essays) from 2020 called 'Unseen minerals all around us'. As a radio programme, the audience was likely to be diverse in terms of age, interests, and background knowledge and experiences.

The speaker was Allison Britt, Director of Mineral Resources Advice and Promotion, Geoscience Australia ("Australia's pre-eminent public sector geoscience organisation"), and she was describing the large number of elements used in constructing a modern mobile phone – apparently someone had put a phone in a laboratory blender and analysed the smoothie produced! (Please note: that is not a safe activity for a home science practical.)

Allison Britt, Director of Mineral Resources Advice & Promotion, Geoscience Australia – at a live recording of 'Okham's razor'. (Source: Twitter)

As a science teacher (well, retired – but once a science teacher, always a science teacher at heart at least) I tend to be primed to focus on the ways in which teachers and scientists 'make the unfamiliar familiar', and Britt used an analogy with multiple targets.

(Read about 'making the unfamiliar, familiar')

(Read about science analogies)

The source domain was something familiar from everyday life – seasoning food.

I thought this worked really well, although as a purist (and, as noted here before, something of a pedant) I would have liked the third of her comparisons to refer to a difference that was a matter of degree (e.g., 'taste better' cf. 'work more efficiently'). That said, Britt's formulation worked better as scientific poetry:

So, just like adding salt and pepper to a meal makes it taste better:

putting a little rhenium in a jet engine makes it burn faster and hotter;

putting a little scandium in an aeroplane makes it lighter and stronger;

and putting a little indium in your mobile phone makes the touchscreen work.
Britt, 2021

This was an example of a science communicator making the point of how adding a small, sometimes trace, quantity of a substance can make a substantive difference to properties. I imagine that virtually everyone listening to this would have effortlessly understood the comparison – a key criterion for an effective teaching analogy.

COVID is like a fire because…

Keith S. Taber

Dampening down COVID? (Image by Iván Tamás from Pixabay)

Analogy in science

Analogy is a common technique used in science and science education. In scientific work analogy may be used as a thinking tool useful for generating hypotheses to explore – "what if X is like Y, then that might mean…". That is, we think we understand system Y, so, if for a moment we imagine that system X may be similar, then by analogy that would mean (for example) that A may be the cause of B, or that if we increase C then we might expect D to decrease… Suggesting analogies has been used as a way of introducing a creative activity into school science (Taber, 2016).

Read about analogies in science

Scientists also sometimes use analogies to explain their ideas and results to other scientists. However, analogies are especially useful in explaining abstract ideas to non-experts, so they are used in the public communication of science by comparing technical topics with more familiar, everyday ('lifeworld') phenomena. In the same way, teachers use analogies as one technique for 'making the unfamiliar familiar' by suggesting that the unfamiliar curriculum focus (the target concept to be taught) is in some ways just like a familiar lifeworld phenomena (the analogue or source concept).

Read about science in public discourse and the media

Read about making the unfamiliar familiar

COVID is like a fire…

So, I was interested to hear Prof. Andrew Hayward, Professor of Infectious Disease Epidemiology and Inclusion Health Research at UCL (University College London), being interviewed on the radio and suggesting that COVID was like a fire:

"Sometimes I like to think of, you know, COVID as a fire, if we are the fuel, social mixing is the oxygen that allows the fuel to burn, vaccines the water that stops the fuel from burning, and COVID cases are the sparks that spread the fire. So, we are doing well on vaccines, but there's lots of dried wood left."

There's quite a lot going on in that short statement. If Prof. Hayward had stopped at "sometimes I like to think of COVID as a fire" this would have been a simile where it is simply observed that one thing is conceived as being a bit like another.

Simile offers a comparison and leaves the listener or reader to work out the nature of the similarity (whereas metaphor, where one thing is described to be another, an example would be 'COVID is a fire', leaves the audience to even appreciate a comparison is being made). Analogy goes further, as it makes a comparison between two conceptual structures (two systems), such that by mapping across them we can understand how the structure of the unfamiliar is suggested to be like the more familiar structure.

That is, there is a mapping (see the figure below) that is based on pairings across the analogy. Here fire and COVID disease are each treated as systems with components that are structured in a parallel way:

COVID (illness): fire
people: fuel
social mixing: oxygen
vaccines: water
COVID cases: sparks

A graphic representation of Prof. Hayward's use of analogy

A lot of us are like kindling

Moreover, having set up this analogy, we are offered some additional information – we are doing well on vaccines (= there is plenty of water to stop fuel burning), but there is still a lot of dried wood. The listener has to understand that the dry wood refers to fuel, and this maps (in the analogy) onto lots of people who can still become infected.

I suspect most people (science teachers perhaps excepted) listening to this interview will not have even explicitly noticed the nature of the analogy, but rather automatically processed the comparison. They would have understood the message about COVID through the analogy, rather than having to actively analyse the analogy itself.

We can stop the sparks spreading the fire

Professor Hayward was asked about contact tracing and suggested that

"…the key thing is the human discussion with somebody who has COVID to identify who their contacts are and to ask them to isolate as well, and that really stops those sparks getting into the population and really helps to dampen down the fire."

That is, that potential COVID cases (that are like sparks in the fire system) can be prevented from mixing with the wider population (who are like fuel in the fire system) and this will dampen down the fire (the illness in the COVID system). {Note 'dampen down' seems to be a metaphor here rather than a true part of the analogy (in which it is the vaccines that have the effect of 'literally' {analogously} dampening down the fire). Stopping sparks mixing with fuel will limit new areas of combustion starting rather than dampening down the existing fire.}

An argument about contact tracing made using the analogy

Again, most people listening to this would likely have taken on board the intended meaning quite automatically, without having to deliberately analyse this answer – even though the response shifts between the target topics (the COVID disease system) and the analogue (the fire system) – so the sparks (fire system – equivalent to infectious cases) are stopped from getting into the population (COVID system – equivalent to the fuel supply).

This is reminiscent of chemistry teaching which slips back and forth between macroscopic and molecular levels of description – and so where references to, for example, hydrogen could mean the substance or the molecule – and the same word may have a different referent at different points in the same utterance (Taber, 2013). Whether this is problematic depends upon the past experiences of the listener – someone with extensive experience of a domain (probably most of the audience of a serious news magazine programme understand enough about combustion and infection to not have to deliberate on the analogy discussed here) can usually make these shifts automatically without getting confused.

Fire requires…AND…AND…

An analogy can only be effective when the analogue is indeed more familiar to the audience (you cannot make the unfamiliar familiar by comparing an unfamiliar target with an analogue that is also unfamiliar) so the use of the analogy by Professor Hayward assumed some basic knowledge about fire. Indeed it seemed to assume knowledge of the so-called 'fire triangle'.

Three factors are need to initiate/maintain combustion: fire may be stopped by removing one or more of these.

This is the idea that for a fire to commence or continue there need to be three things: something combustible to act as fuel; AND oxygen (or another suitable substance – as when iron filings burn in chlorine – but in usual circumstances it will be oxygen); AND a source of energy sufficient to initiate reaction (as burning is exothermic, once a fire is underway it may generate enough heat to maintain combustion – and sparks may spread the fire to nearby combustible material). To extinguish a fire, one needs to remove at least one of these factors – water can act as a heat sink to decrease the temperature, and may also reduce the contact between the fuel and oxygen. Preventing sparks from transferring hot material that can initiate further sites of combustion (providing energy to more fuel) can also be important.

Unobtrusive pedagogy

The quotes here were part of a short interview with a broadcast journalist and intended for a general public audience. Prof. Hayward introduced and developed his analogy as just sharing a way of thinking, and indeed analogy is such a common device in conversation that it was not obviously marked as a pedagogic technique. However, when we think about how such a device works, and what is expected of the audience to make sense of it, I think it is quite impressive how we can often 'decode' and understand such comparisons without any conscious effort. Providing, of course, that the analogue is indeed familiar, and the mapping across the two conceptual structures can be seen to fit.

Works cited:

Taber, K. S. (2013). Revisiting the chemistry triplet: drawing upon the nature of chemical knowledge and the psychology of learning to inform chemistry education. Chemistry Education Research and Practice, 14(2), 156-168. doi:10.1039/C3RP00012E

Taber, K. S. (2016). 'Chemical reactions are like hell because…': Asking gifted science learners to be creative in a curriculum context that encourages convergent thinking. In M. K. Demetrikopoulos & J. L. Pecore (Eds.), Interplay of Creativity and Giftedness in Science (pp. 321-349). Rotterdam: Sense. (Download the author's manuscript version of this chapter.)

Opposites avoid attracting

Do species become more different from one another to avoid breeding?

Keith S. Taber

They say "opposites attract". True perhaps for magnetic poles and electrical charges, but the aphorism is usually applied to romantic couples. It seems like one of those sayings that survives due to the 'confirmation bias' in human cognition. That is, as long as from time to time seemingly unlikely couplings occur, the explanation that 'opposites attract' seems to have some merit, even in it only applies to a minority of cases.

Trying to avoid a fight

What got me thinking about this was an interview (on BBC's Inside Science radio programme/podcast) with Dr Jacob Dunn, Associate Professor in Evolutionary Biology at Anglia Ruskin University, who studies primate vocal communication. He was discussing his research into the calls of tamarin monkeys in the Amazon rainforest, and in particular the calls of two different species where their ranges overlap.

Apparently, in the area of overlap the red-handed tamarins seemed to have adapted one of their calls so it sounds very similar to that of the pied tamarins. (N.b. The images above represent two contrasting species, just as an illustration.) The suggested explanation was that this modification made it more likely that the monkeys of different types would recognise each other's calls – in particular that "…they are trying to be understood, so they don't end up in a fight…".

Anthropomorphism?

I wondered if these monkeys were really "trying" to achieve this, or whether this might be an anthropomorphism. That is, were the red-handed tamarins deliberately changing their call in this way in order to ensure they could be understood – or was this actually natural selection in operation – where, because there was an advantage to cross-species communication (and there will be a spread of call characteristics in any population), over time calls that could be understood by monkeys of both species would be selected for in a shared niche.

Then again, primates are fairly intelligent creatures, so perhaps Dr Dunn (who, unlike me is an evolutionary biologist) means this literally, and this is something deliberate. Certainly, if the individual monkeys are shifting their calls over time in response to environmental cues, rather than the shift just occurring across generations, then that would seem to suggest this is learning rather than evolution. (Of course, it could be implicit learning based on feedback from the responses to their behavior, and still may not be the monkeys consciously adopting a strategy to be better understood.)

Becoming more distinct

Dr Dunn's explanation of the wider issue of how similar animals will compete for scarce resources intrigued me:

"When you have species that are closely related to one another and live in sort of overlapping areas there's quite a lot of pressure because they're likely to be competing for key resources. So, sometimes we see that these species actually diverge in their traits, they become more different from one another. Examples of that are sort of coloration and the way that animals look. Quite often they become more distinct than you would expect them to, to avoid breeding [sic] with one another."

My initial reaction to this was to wonder why the two species of monkeys needed to avoid breeding with each other. 'Breeding' normally refers to producing offspring, reproduction, but usually breeding is not possible across species (except sometimes to produce infertile hybrids).

Presumably, all tamarins descended from a common ancestor species. Speciation may have occurred when different populations become physically separated and so were no longer able to inter-breed (although still initially sexually compatible) simply because members of the two groups never encountered each other. Over time (i.e., many generations) the two populations might then diverge in various traits because of different selection pressures in the two different locations, or simply by chance effects* which would lead to the two gene pools drifting in different ways.

(* Read about 'Intergenerational couplings in the family: A thought experiment about ancestry')

Two groups that had formed separate species such that members of the two different species are no longer able to mate to produce fertile offspring, might subsequently come to encounter each other again (e.g., members of one species migrating into to the territory of the other) but inter-breeding would no longer be possible. A further mechanism to avoid breeding (by further "diverge[nce] in their traits") would not seem to make any difference.

If they actually cannot breed, there is no need to avoid breeding.

A breeding euphemism?

However, perhaps 'breeding' was being used by Dr Dunn as a euphemism (this was after all a family-friendly radio programme broadcast in the afternoon), as a polite way of saying this might avoid the moneys copulating with genetically incompatible partners – tamarins of another species. As tamarins presumably do not themselves have a formal biological species concept, they will not avoid coupling with an animal from a different species on the grounds that they cannot breed and so it would be ineffective. They indulge in sexual activity in response to instinctive drives, rather than in response to deliberate family planning decisions. That is, we might safely assume these couplings are about sexual attraction rather than a desire to have children.

I think that was what Jürgen Habermas may have meant when he wrote that:

"…the reproduction of every individual organism seems to warrant the assumption of purposiveness without purposeful activity…"

In terms of fitness, an animal is clearly more likely to have offspring if it is attracted to a sexually comparable partner than a non-compatible one. Breeding is clearly important for the survival of the species, and uses precious resources. Matings that could not lead to pregnancy (or, perhaps worse from a resource perspective, might lead to infertile hybrids that need to be nurtured but then fail to produce 'grandchildren'), would reduce breeding success overall in the populations. Assuming that a tamarin is more likely to be attracted to a member of a different species when it does not look so different from its own kind, it is those monkeys in the two groups that look most alike who are likely to be inadvertently sharing intimate moments with biologically incompatible partners.

A teleological explanation

Dr Dunn's suggestion that "quite often [the two species] become more distinct than you would expect them to, to avoid breeding with one another" sounds like teleology. That is, it seems to imply that there is a purpose (to avoid inter-breeding) and the "species actually diverge in their traits" in order to bring about this goal. This would be a teleological explanation.

(Read about 'Teleology')

I suspect the actual explanation is not that the two species "come more distinct…to avoid breeding with one another" but rather than they come more distinct because they cannot breed with each other, and so there is a selection advantage favouring the most distinct members of the two different species (if they are indeed less likely than their less distinguishable conspecifics to couple with allospecific mates).

I also suspect that Dr Dunn does not actually subscribe to the teleological argument, but is using a common way of talking that biologists often adopt as a kind of abbreviated argument: biologists know that when they refer to evolution having a purpose (e.g., to avoid cross-breeding), that is only a figure of speech.

Comprehension versus accuracy?

However, I am not sure that is always so obvious to non-specialists listening to them. Learners often find natural selection a challenging topic, and many would be quite happy with accepting that adaptations may have a purpose (rather than just a consequence). This reflects a common challenge of communicating science – either in formal teaching or supporting public understanding.

The teacher or science communicator simplifies accounts and uses everyday ways of expressing ideas that an audience without specialist knowledge can readily engage with to help 'make the unfamiliar familiar'. However, the simplifications and approximations and short-cuts we use to make sure what is said can be understood (i.e., made sense of) by non-specialists also risks us being misunderstood.

Albert Einstein and John the Baptist

Keith S. Taber

What is the relationship between Albert Einstein and St. John the Baptist?

Why would someone seeking to communicate scientific ideas to a broad readership refer to St. John?

Spoiler alert: in a direct sense, there clearly is no relationship. St. John lived in Palestine two thousand years ago, was a preacher, and is not known to have had any particular interest in what we think of as physics or science more generally. Albert Einstein was a theoretical physicist, and probably the most famous scientist of the twentieth century, perhaps of all time.

It is fair to point out both were Jewish: John can be considered a Jewish prophet. There has been much speculation on Einstein's religious thought. Of Jewish background, he was subject to the Nazi's fascist policies in Germany and fled to spent much of his life in the U.S.A. Sometimes considered an atheist, Einstein did talk of God (as not playing dice for example – that is, not leaving room in the Universe for completely random events) but it is sometimes claimed he use the idea of God as a metaphor for some kind of pantheistic or general spiritual background to the universe. In general though, he stuck to physics, and campaigned on issues like world peace.

(Read about 'The relationship between science and religion')

So, why raise the question?

My posing this question was motivated by reading something written by Herman Weyl (1885 – 1955) who is described by Wikipedia as "a German mathematician, theoretical physicist and philosopher". In one of his writings Weyl referred to Hendrik Lorentz who (again according to Wikipedia) was "a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect".

This is how Weyl described Lorentz:

"the Dutch physicist H.A. Lorentz who, as Einstein's John the Baptist, prepared the way for the gospel of relativity."

Weyl, 1952/2016, pp.131-132.

Those studying physics at high levels, or reading about relativity theory, will probably have heard of the 'Lorentz transformations' that are used in calculations in special relativity.

An extended metaphor?

What Weyl is doing here is using a metaphor, or perhaps an analogy. In a metaphor a writer or speaker says that something is something else – to imply it has some attribute of that other thing.

(Read about 'Science metaphors')

In an analogy, one system is compared with another to show that there is, or to suggest that perhaps might be, a structural similarity. Usually analogies are presented as an explicit comparison (X is like Y: i.e., rather than 'Lorentz was Einstein's John the Baptist', perhaps 'Lorentz was like Einstein's John the Baptist in the sense that…')

(Read about 'Science analogies')

As Weyl does not say Lorentz was like a John the baptist figure, or played a role similar to John the Baptist, but that he was "Einstein's John the Baptist" I would consider this a metaphor. However, it is an extended metaphor as the comparison is explained as justified because Lorentz "prepared the way for the gospel of relativity".

That could be seen as a second metaphor in that relativity is normally considered a theory (or two theories, special relativity, and general relativity), and not a gospel – a word that means 'good news'. So Weyl is saying that Lorentz prepared the way for the good news of relativity!

Making the familiar unfamiliar?

When I read this comment I immediately felt I appreciated the point that Weyl was seeking to make. However, I also felt that this was a rather odd comparison to make, as I was not sure how universally it would be understood.

Those communicating about science, whether as science teachers or journalists or (as here) scientists themselves looking to reach a general audience, have the task of 'making the unfamiliar (what people do not yet know about, and may indeed seem odd) familiar'. There are various techniques that can be used, and often these involve some form of comparison of what is being told about with something that is in some ways similar, and which is already familiar to the audience.

(Read about 'Making the unfamiliar familiar')

I attended 'Sunday school' from a young age (I think before starting day school if I recall correctly) at a London City Mission church, and later at a Methodist Church, where I became a Sunday school teacher before i went off to University. I therefore learnt quite a bit about Christianity. Anyone with such a background will have learnt that John the Baptist was a cousin of Jesus Christ, who preached 'the coming of the Lord' (i.e., the Jewish messiah, identified in Christianity with Jesus), and baptised Jesus in the River Jordan as he set out on his mission as a preacher and healer. John is said to have told his congregation to "prepare ye, the way of the Lord!" (the title of a song in the musical 'Godspell').

Someone knowing about Christianity in this way (regardless of whether they accept Christian teaching, or even the historical accuracy of the Baptism story) would likely immediately appreciate that just as John prepared the way for Jesus' ministry in first Century (CE) Palestine, so, according to Weyl, Lorentz prepared physics, laid important groundwork, for Einstein's work on relativity.

When you have the necessary background, such comparisons work effectively and quickly – the idea is communicated without the reader having to puzzle over and interpret the expressions "Einstein's John the Baptist" and "gospel of relativity" or deliberate on what is meant by 'preparing the way'. That is, the if the reader has the relevant 'interpretive resources' then understanding is an automatic process that does not require any conscious effort.

Culture-specific interpretive resources?

But I wondered what someone would make of this phrase ('Einstein's John the Baptist') if they did not have knowledge of the Bible stories? After all, in many parts of the world most people are not Christians, and may have little or no knowledge of Christian traditions. Did Weyl just assume everyone would have the background to appreciate his comparison, or did he assume he was only writing for an audience in certain parts of the world where this was common knowledge?

Certainly, as teachers, our attempts to help our students understand abstract ideas by making references to common cultural phenomena can fall flat if the learners are not familiar with those phenomena. It is counter-productive if the teacher has to interrupt their presentation on some abstract idea to explain the very comparison that was meant to help explain the scientific concept or principle. If you have no idea who 'John the Baptist' was, in what sense he 'prepared the way' for Jesus, or or how the term 'Gospel' came to be attached to the accounts of Jesus' life, then it is not so easy to appreciate what Lorentz was to Einstein's work from Weyl's prose. We can only make the unfamiliar familiar by using cultural references when we share those references with those we are communicating with.

Work cited:

Weyl, H. (1952/2016). Symmetry (New Princeton Science Library edition ed.). Princeton, New Jersey: Princeton University Press.

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But perhaps Mr Javid does not actually mean that COVID likes Autumn and Winter?

Addendum: 1st December 2021

Works cited:

Footnotes:

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Work cited:

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The man-made is not 'natural'

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96% natural origin

96% natural origin

97% natural origin

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Source cited:

Footnote

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Work cited:

Note:

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Work cited:

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Work cited:

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Work cited:

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Works cited:

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A teleological explanation

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What is the relationship between Albert Einstein and St. John the Baptist?

At least ⁹/₁₀^ths natural origin