A Post-Truth Test Tube

I’m currently a recovering addict. A few months ago on a whim I joined a FB group to debate Earth’s shape. I’ve come across flat Earthers before, online at least. Whether I’ve encountered adult Westerners who believe Earth is flat, I don’t know. Finding the group highly addictive, I became one of the main posters and enjoyed it a lot, but it isn’t really the best employment of one’s time. That said, it does constitute an interesting case study of the way we think and behave.

The useful thing about looking at flat Earther psychology is that it’s firmly established that Earth is spheroidal. The room for doubt is practically submicroscopic on this matter, so there’s no risk of being wrong or being drawn into believing that it’s flat, and because of that, rather than becoming embroiled in arguments which might persuade one, one can instead just examine how flat Earthers justify their position. Positions plural, actually. Most flat Earthers seem to believe we are on an almost flat surface under a transparent dome with the Sun going round us, but there are other views. For instance, some believe Earth as we know it is surrounded by broader rings of continents and oceans to which we have no access, and to be honest that is a really fascinating and appealing view which might go some way towards addressing the claustrophobia of the more restricted version, and a few of them seem to believe we are on an infinite plane. I say “seem to” because this is one of the problems with trying to work out what’s pagoing on: are they serious about this or just kidding around?

The answer to this is probably that it depends. This is one thing about groups seen from a distance as opposed to groups examined more closely: the details of individual differences become clearer. As far as I can tell, there seem to be several categories of “flat Earther”. There certainly are people who are just joking, and in fact when the flat Earth society was reëstablished in I think the ‘noughties, it appears to have been a joke. There are also trolls, which is a slightly different thing because I suspect the people concerned enjoy either tweaking the feathers of people they see as nerds or deceiving people into thinking it’s flat for fun. This seems to blend into a group of people who are trying to make money out of gullible people and present themselves as serious campaigners and investigators on the issue. Then there are their followers, who have bought into the whole thing, which is where the conspiracy theories start. There are few people who think independently on the issue, and there are then religiously-motivated people and people who are simply persuaded but not particularly religious. Finally, there are enquiring people who don’t seem to be skilled at fact-checking and simply feel that the two views, flat and round Earth, are equally open to question: kind of “false balance” people who think there is enough evidence for it to be a fair fight.

I can certainly vouch for the power of the force of gravity here, because I couldn’t leave it alone. Rather than manifesting itself as concluding Earth was flat for me, it came across as a compulsion to post and address issues even though I knew it wouldn’t persuade anyone to do it. It may be worth asking myself questions about why I felt the draw of the belief system and attempting to change it, and why “flat Eartherism” in particular has this pull. I know that I have obsessive-compulsive tendencies although I’m not going to pathologise that or embrace a self-diagnosis, but it is there and it probably is a factor for me. But it was also very time-consuming. Cutting my ties with it is also a judgement call, because it’s possible for some people actually to make a living out of addressing the issue. There are, for example, YouTube channels devoted to debunking flat Eartherism as well as all the so-called “Truth” channels focussing on promoting it. Pushing it far enough might in theory have brought some money in although I’m small fry in that pond,so probably not.

This raises the question of whether it’s harmless. In a way, this is beside the point. It’s more that the occurrence of the belief, which often seems to be a long way down the line for many people who have come to question other widely-held beliefs such as how genuine the Apollo program was, is symptomatic of poor fact-checking abilities, and when I say “ability” I do believe critical thinking can be developed in most people. They could even develop it themselves, although it may be difficult to overcome emotional and social attachment to a belief. It is also true that believing Earth is flat is going to exclude people from certain lines of work, or at least make it difficult for them to pursue them, such as on large engineering projects or piloting international aircraft, so maybe human resources are lost to society because of this belief. More broadly, however, there are the issues of overvalued ideas, vulnerability to more negative consequences from other beliefs (anti-vaccination comes to mind) and the general feeling of distrust and fear which may arise from the idea that there is a vast conspiracy to keep all this from the public. The size of this effort would be a lot bigger in this case than any other conspiracy I can think of, because so much more depends on the shape of the planet than other things.

Looking at the trolls, and here I presume that trolls exist and I’d expect there to be at least a few, an outsider would see them as pretending to be of low intelligence and poorly-educated, which is an odd thing to do to one’s reputation. I imagine that they are deriving entertainment from successfully deceiving others or annoying people they may see as nerds. I have in common with these people that I’m drawn into wasting my time and energy on a project which is not very productive and a bit of a pointless endeavour. Trolling is something I don’t fully understand and I sometimes wonder if trolls even know what their real motivations are, because it’s so easy to develop an online persona unintentionally. Beyond this, I can even develop a little conspiracy hypothesis of my own that the whole exercise is a distraction from more consequential issues for all of us, not just the flat Earthers. It’s possible to drop the whole intentional fallacy from this idea and just say, this is what it does and it doesn’t matter if it’s a concerted effort or not. This is one reason why I’ve given up on them, because it really is a bit of a waste of time.

There’s also something like the “sunk cost fallacy” operating here, perhaps on both sides. The sunk cost fallacy is the feeling that because you’ve spent a lot of time and resources, and have perhaps lost a lot in your own life socially and otherwise by pursuing a particular goal, it’s hard to back out of it. If you’ve become a flat Earther, you may value the comradeship of the people around you, online or off, and in many sallies away from majority opinion, people can lose friends and acquaintances, and also opportunities, and all of these things amount to costs. Another form of cost is the embarrassment one may experience from admitting one was wrong.

All that said, we should avoid “othering” people whose beliefs we’re confident are incorrect. One reason for this is that having delusions is part of the healthy human psyche, and even where they don’t serve a positive purpose they may nonetheless exist. Failure to acknowledge that we rationalise our beliefs, even if they’re correct and well-supported by evidence, is lack of self-awareness. Our beliefs also have functions beyond the practical. They can be like interests which bind a club together, and of course this is a substantial part of the function of religious beliefs. I have long maintained that religious belief of some kind is inevitable and therefore that we shouldn’t always resist it, as it can play a valuable part in maintaining good mental health. The question here is whether believing Earth is flat is worthwhile enough for the cost paid through lack of contact with reality.

I have an acquaintance who used to be quite a close family friend. We even went on holiday together and attempted some joint business ventures. Quite some time back, they expressed the view that the Apollo missions were a hoax. I engaged with them on this but they didn’t change their mind. I should point out at this stage that this person was a faithful Green Party voter and possibly even a member of the party. They were also an alternative medicine practitioner. This particular category of work has a lot of variation in it and can be stigmatised. It’s also how many people see me. Nonetheless there is a perceived issue of evidence supporting efficaciousness or otherwise which plainly does apply to some modalities. During the lockdown, they expressed support for Trump, not just regarding his approach to the pandemic but more widely. I could make a link between belief that Apollo was a hoax and this later conclusion. I found the incident very saddening and disappointing.

It seems that a lot of the more vocal flat Earthers nowadays connect their beliefs to the Apollo hoax idea, which makes sense if you think Earth is flat, and also to anthropogenic climate change denial, the New World Order conspiracy theory and anti-vaccination. Of all of these, I should point out that in the 1990s I was close to being anti-vaxx, although my problem was that as usual my opinion wasn’t similar to that of others. I tended to get lumped in with anti-vaxx people even though my actual position was that I wanted some vaccinations to be given by inhaler or nebuliser, not injection, rather than being opposed to vaccinations as such, and as such wasn’t opposed to the single tetanus jab or OPV per se. Now that this is being done routinely with children, I no longer have that objection although I am still concerned about the evolution of slow viruses by attenuation. However, I’ve long felt that the real problem with vaccination resistance is that much of the population doesn’t feel respected or listened to, and I wonder also if this is a factor here. This is one conspiracy theory I’ve seen from the inside. I get the impression also that flat Eartherism is the “hard drug” as it were. It’s the last thing people end up believing in once they’ve accepted all the others.

Due to the universal nature of delusions, a more useful marker for mental illness may be the overvalued idea. It isn’t so much that people believe Earth is flat as that they’re preoccupied with the idea and it comes to dominate their lives. It is understandable that if you think something so fundamental is different than how it’s presented publicly, you probably would think it was quite important to do something about it, and are also likely to think there may be a sinister reason behind the deception. Is it an overvalued idea for a starving person to focus on finding something to eat?

According to the conspiracy theory, the rationale behind persuading the world that Earth is round is to dislodge humans from the centre of creation and lose Earth in the vastness of an impersonal Universe, thereby undermining theism. If that were the aim, it seems like overkill. Why would it be necessary to keep “building” the Universe in the way they would have had to have been doing, for instance initially portraying distant galaxies as nebulæ within our own and likewise with quasars, before promoting them to enormous distances? There’s another perspective within this one that the Big Bang theory, evolution and flat Earthism are all part of a plot to do this, and are associated with the Illuminati, the Masons and unfortunately sometimes the Jews. This last association probably indicates why all this might be dangerous.

I actually find the bog-standard flat Earther view to be claustrophobic and think it makes the world feel like a prison. It also seems to guarantee that there is no life anywhere except on Earth, which for me is a deal-breaker for theistic prayer and worship. If God chooses to sustain a Universe where we are the only sentient beings in a single biosphere, it seems like God cannot be related to by humans on an emotional level. This makes more sense if one does see the Universe as vast, but it still works to some extent on the prison world hypothesis because whereas God could have chosen to sustain a vast Universe, she chose not to, which means we’re trapped conceptually. Of course, we could still be literally trapped on Earth in a vast Universe, but at least the way things are we do know how enormous the world is and the contrast with the largely lifeless Universe in which we’re embedded emphasises the specialness of this planet. This would be less true of an infinite plane Universe though there is still the problem of apparently being at its centre, since it is supposed to be infinite and therefore has either no centre or a ubiquitous one.

Of course one might be forgiven for asking why this matters given the current world situation, and that’s a valid question. It would be easy to come up with a conspiracy theory of one’s own here, that fine minds are being distracted from what matters in order that atrocities can be committed, but in response to that I would say that many of the minds which are being distracted, mine included, are rather far from fine and wouldn’t make much of a contribution anyway, and also that it’s a basic principle to focus on the consequences of a set of circumstances more than the cause, which is a distraction in itself and also symptomatic rather than the more general underlying cause of the problem, which would be worth addressing. The question remains, then, of whether one should bother with this at all. Unfortunately the answer seems to be yes, because analysis of how the issue has arisen allows insight into how other more serious issues have, or might do in future. It’s a kind of model for how, for example, Russian trolls might influence voting in elections or how the Rohingya genocide was engineered.

The idea of conspiracy has tended to centre on NASA as a major actor in this realm. This is peculiar as the sphericality of the planet seems to have been first suggested by Pythagoras in the sixth century BCE, its circumference measured by Eratosthenes in the third century BCE and it was then accepted by the Church into the European Middle Ages, to the extent that they used to discuss whether it was possible that God would have created land on the opposite side of the globe from Christendom because if it were inhabited, it might not be feasible for the Word of God to reach them. I have to admit to being a little confused by this as it seems to imply their view of gravity was quite modern, but it is nonetheless so.

This does, however, raise the question of what kinds of people accepted Earth as round at the time. It does seem quite likely that the average European peasant would not have had an explicit view of Earth’s shape at the time, as they had more pressing concerns, but that might be to underestimate their mentality. Likewise, it also seems entirely feasible that even today many peoples who have not had contact with Western civilisation would assume Earth is flat. The rather startling figure of seven percent of Brazilians, though, appears to refer to Europeanised Brazilians rather than the likes of the Yanomami.

I’ve noticed also that some flat Earthers are merely repeating claims without checking up on them. Two of these in particular are that until the 1920s, US public schools taught that the world was flat. This does not tally well with discoverable facts about history. It was the work of a couple of minutes to locate a digital archive of nineteenth century school geography textbooks, on whose first page it was stated categorically that Earth is round and we live on its exterior. This particular work was published in 1889. It is possible that children were being taught that the world was flat at a later date, for a couple of reasons. One is that teachers don’t necessarily teach what is on the curriculum, and could be either poorly educated themselves or believe that it’s flat, in which case they would presumably teach that if the issue arose. Another is that it isn’t clear how far such textbooks had penetrated by this time. A second, less consequential, claim is that Eratosthenes was inserted into textbooks in the 1980s. I am in the happy position of being able to refute this. I first read of his experiment in ‘The Collins New World Of Knowledge Encyclopedia Of Science And Technology’, published I think in 1973. It’s quite an audacious claim that it was added more recently than that, and I expect that if I were to bother to look, I would find earlier examples. These two claims make me feel that it’s almost Last Thursdayism. A rather similar claim is that NASA pictures taken in the 1960s are CGI, which is very peculiar as there would’ve been many other ways to fake images at that time.

Getting back to NASA, there are two oddities about this particular focus. One is that their existence is completely superfluous to the evidence Earth is round, which as I said is millennia old. Another is that they are only one of many space agencies, which I think probably reflects the US-centric nature of Flat Earthism. There are around sixteen space agencies with launch capability and several times that number capable of doing things like building satellites to be launched by others. These two aspects seem to reveal a considerable degree of ignorance about general knowledge. This is coupled with two other aspects of how flat Earthers view education. They often view mathematics with suspicion and are unwilling to apply the scientific method, often engaging in ad hominem attacks when these are used. All of this taken together had led me to feel that they have been poorly served by the schooling system. They seem to regard belief in a round Earth to result from indoctrination when well-expressed scientifically based tests which are easily reproduced by someone without elaborate equipment are actively avoided. This makes it more likely that their beliefs are motivated by religious sensibilities, but unfortunately not open-minded or progressive ones.

The Bible does seem to imply that its human writers tended to assume Earth was flat. Apart from references to “the four corners of the Earth” in the Tanakh, Jesus is depicted as rising into heaven above Earth, which suggests a sandwich-like cosmology with heaven constituting an entirely horizontal layer above the terrestrial realm. It also raises a question in my mind which I’ve been unable to answer so far. If Biblically literalist Christians (and also many Muslims but not religious Jews on the whole) are often young Earth creationists due to their approach to their sacred texts, why is it less common for them to be flat Earthers? Such a view is clearly assumed by Biblical authors just as creationism is, yet the view is much less popular. If I could crack this conundrum, it might lead me towards better arguments against creationism. This might also be a massive waste of time of course, like the rest of it.

A major problem with how flat Earthers interact with the rest of humanity is that we who have an accurate view of Earth’s shape are often guilty of ridicule and insult towards them. This leads to entrenched positions which are defended and attacked not by reasoned argument but through largely emotional interaction. I can imagine a flat Earther becoming more relaxed about her beliefs and getting on with her lives in other ways, and then eventually not caring much about Earth’s shape or quietly conceding she was wrong, but if that day does dawn in their lives, it will do so a lot later if they’ve been pummeled for their beliefs in this way. They’re likely to thrive on persecution, and it is in any case wrong to behave thusly towards them. This may fuel the retention of the beliefs in question.

Flat Earthers, oddly, seem to see the rest of us as indoctrinated “sheeple”. Both sides seem to accuse the other of the same things, and for once because we are able to state confidently that Earth is not flat and back that up with evidence, it’s possible to separate the accusations from the reality, but it is still interesting that they perceive us as we perceive them. Unlike us, sadly in a way, the evidence they present is not remotely convincing and could only be believed by someone who was both unaware of science in the sense of it being a body of information and of the scientific method. They often think of scientists as having their views dictated by monetary interests, and to be honest this has been known to happen, as with medical research into the consequences of smoking tobacco, but in the case of investigating Earth’s shape this is easily reproducible. I have, as mentioned here before, suggested that in order to avoid accusations of manipulation, they come up with their own falsifiable test but I have never known one to do that.

It only takes one reliable falsification for a hypothesis to be rejected. In the case of Earth being flat, many falsifications are available. It would be interesting if the hypothesis that Earth is round could be falsified, but apart from minor details such as its oblateness this has not happened so far and nothing offered by flat Earthers that I’m aware of has succeeded in doing so. Good quality evidence would be most welcome, but is not forthcoming. The closest they get is objects being visible which seem to be beyond the line of sight, but when this is definitely testable it can be explained by refraction of light by the atmosphere, which can only make objects appear higher, i.e. visible if somewhat beyond the horizon, than they would be if no atmosphere was present. Other, similar attempts have been made, such as the claim that RADAR works beyond the horizon. It does, but that’s a special kind of RADAR called, appropriately, “over the horizon RADAR” and works by bouncing short wave radio waves off the ionosphere. Similarly, a microwave mast in Cyprus can communicate with one in the Lebanon, and since microwaves only work by line of sight this would only be possible if each is above the horizon from the other’s perspective, but in fact Lebanon is quite a mountainous country and this is not at all problematic.

I’ve also noticed quite basic misunderstandings which seem to result from not reading sources closely. One flat Earther claimed that my own claim that seismic waves indicated that there was an apparently spheroidal core centred six thousand odd kilometres below the surface was outdated because Earth’s core was not made of iron and nickel but of ionised light elements such as hydrogen and oxygen, and provided a link. What they actually linked to, if followed, reveals a paper which was scientifically quite rigorous but didn’t make this claim. Rather, it claimed that seismic waves appeared to show that Earth’s core was an alloy of iron and nickel combined with ionised hydrogen and oxygen which behaved differently due to the high pressure. This particular flat Earther said they were an ex-engineer who had accepted all their life that the planet was round, but changed their mind later on. Although I’m not questioning that, I do wonder if it’s a sign of cognitive decline, because the paper did not claim anything like they said it did. There were also many spelling mistakes not similar to autocomplete errors in their writing, which again doesn’t show for sure that they’re mistaken but does suggest something regarding their reliability.

All of this, then, seems to be the consequence of something characteristic of our time, perhaps like the Targeted Individual community, where people diagnosable as in a markèdly delusional condition meet others online who reinforce their beliefs of persecution, but combined with poor educational attainment and critical thinking skills. However, we can’t feel all superior about this because not only is it partly about bad luck with the education system, but it’s also nothing more than a delusion we happen not to share, unlike the individual delusions the rest of us happen to have.

If you’re a flat Earther reading this, I want to say the following to you. Although you’re wrong, I will also inevitably be wrong about some of my beliefs, and the reason you’re wrong is not connected to you being in the minority. Even if only a single person in the world believes something, the mere fact that it’s just the one person has no bearing on whether it’s true or not. I don’t want you to feel I treat you with contempt, and if any of what I’ve written has made you feel this way, I sincerely apologise. It takes courage to stick to a belief which the whole world is against, and I respect you for that. Who knows what else we might have in common outside this area?

Humanoids

As a child, I used to be very irritated by anthropomorphic robots. It felt like people weren’t taking the idea seriously when they attempted to depict an automaton in such a way that it was like Robbie The Robot from ‘Forbidden Planet’, and also that form did not follow function here. Why would a robot – an apparatus designed to do the work of a human – have to look like a human? In fact there are good reasons why that would be good, but before I go there, I ask you to consider this monstrosity:

For some reason, not hard to guess, someone decided to drape a woman across this machine’s arms and I expect it was quite successful. The other, main one, which springs to mind is this:

Nowadays I feel a kind of grudging respect for these designs, but even still, things like the obviously valve-inspired heads, also seen in ‘Fireball XL-5’ and elsewhere, are rather annoying. There seems to be neither a reason for the gyroscope-like “eyes” in the top illustration nor any way in which they could function as visual apparati if that’s what they’re supposed to do. One is left with the question of what the fictional designer was trying to “say” with these, in a fashion kind of ways. It doesn’t help that the appearance is so approximate. But on another level they’re fun, I suppose, but at the time I just found them irritating.

When I became a fan of ‘The Hitch-Hiker’s Guide To The Galaxy’, I took pains not to imagine Marvin as humanoid. It actually makes sense that he wouldn’t be because although H2G2 includes humanoid aliens, many of them aren’t, so why bother making “him” look like one? Sirius Cybernetics would be missing out on the non-humanoid market there. He was first represented as human visually in the 1981 TV series, but is implied to be an android in the radio, and in fact explicitly described as one, although he’s also called “paranoid”, which doesn’t actually make sense as he’s depressive rather than delusional. However, he’s bilaterally symmetrical, having a pain in all the diodes down his left side, and has two arms and ears:

I’ve worked out that if I stick my left arm in my right ear I can electrocute myself.

• Marvin, Fit the Tenth.

My default vision at the time of what a robot looked like was something like Hewey, Dewey and Louiey from the ‘Silent Running’ film, but with an air cushion instead of legs and metal rings to manipulate objects encircling the main body. If I could draw at all, I’d show you, but I can’t really.

In fact there is a good reason for robots operating in an environment shared with humans to be humanoid. A domestic robot, for example, would presumably be interacting with objects designed to be interacted with by humans, such as furniture, doors, windows and perhaps domestic machinery such as washing machines and vacuum cleaners, so the most logical design for such a machine is to make it pretty much the same shape and size as the majority of humans. There probably isn’t any external feature of a human body which is not somehow involved in this kind of interaction, and in any case the human musculoskeletal system and sense organ arrangements are quite well “designed”, so why not? In a way, we already have a basic design for a humanoid robot in the form of human anatomy, and if it ain’t broke don’t fix it, eh?

Other environments and functions might need different kinds of robot though. For instance, a remote-control device for bomb disposal like the one above is absolutely fine and having, for example, a walking robot to do the same, causing vibrations which might set the bomb off, is probably a really bad idea. In general, robots which move along solid surfaces have wheels rather than legs, and the main reasons for legs are to traverse highly irregular solid ground and because an organism is usually completely connected internally and therefore can’t have wheels. There are exceptions to this, such as flagella, whip-like organelles used for swimming which have gears, but on the whole animals need to have blood, muscles and nerves connected to locomotory organs, so they can’t easily have literal wheels.

A number of political and social issues arise with humanoid robots. You may have noticed that I’m not saying “‘droid” or “android” in this post. The reason for this is that the word “android” doesn’t mean “in the shape of a human” but “in the shape of a man”. An android pelvis is one which is shaped like the typical XY human pelvis, and can therefore be problematic for giving birth vaginally. The Greek equivalent to “humanoid” would be “anthropoid”, but this term is usually used biologically to refer to gorillas, orangutan, bonobos, chimps and humans rather than something mechanical, so that also is ruled out. Androids are assumed to be male. If a robot is “female”, it’s called a “gynoid”, and is likely to be a sex robot. The stereotypes of gender are much stronger and less questioned in the realm of robotics than the human world, and perhaps this is not surprising because robots are in a sense slaves, although that metaphor has now become rather tired.

There is a campaign against sex robots, founded oddly enough in Leicester. Its aims are to abolish porn robots of women and girls, prevent the manufacture of child robots for pædophiles, challenge the normalisation of pornbots (their term as far as I know), encourage a model of sexuality and sex as mutual, create a vision of technology where women and girls are valued and work across the political spectrum to value the dignity of women and girls. The issues are complex. Augustine used to argue that we only had duties towards non-human animals because we might otherwise transfer their abuse to humans, and there are cases of people who were cruel to cats and dogs when they were children who grew up to be serial killers as adults. I find that argument very suspect because, regardless of veganism, cruelty to other species was the norm among boys I knew as a child and they clearly did not all become serial killers as men. Applying this to sex robots, the issue seems to be similar, that the use of sex robots would lead to disrespect and abuse of women and children in the long run. The big problem with this view is what it ends up looking like if sex robots become sentient, because at that point it seems to become practically identical to genocide, and it’s also reminiscent of the argument that Cannabis is a gateway drug, which is clearly nonsense, at least where drugs are decriminalised. There is a story to be told here and I may do that one day.

Nonetheless, the Campaign Against Sex Robots does have a point. A gynoid right now is likely to be a sex object, and this is deeply problematic. However, there are examples of non-sexualised gynoids, particularly more recently. A related issue was mentioned on the BBC radio podcast ‘White Mischief’: there is a very strong tendency for androids to be White, and also white in colour. If androids in fiction were both servile and dark-“skinned”, that would communicate certain disturbing issues. The podcast also pointed out something I had never noticed before in ‘Blade Runner’: the unquestionably human population of Los Angeles is ethnically diverse, but all the androids and possible androids are White, because this allows them to pass. Whiteness constitutes inconspicuousness and neutrality, so all the escaped Nexus 6 androids are White, as are Deckard and Rachel. It was then suggested that rather than giving real androids humanoid colours either characteristic of a given ethnicity or associated with names associated with those, such as black, yellow or white, they should instead be made completely non-human in colour, such as saturated green or blue.

The history of the word “humanoid” is interesting. During the nineteenth Christian century, the word was applied by White people to indigenous people in South America and the like. In a somewhat related usage, the humans in the original ‘Planet Of The Apes’ films and TV series were referred to as humanoids. Early last century it referred to non-Homo sapiens hominids such as Australopithecines and Neanderthals. Nowadays the words used there, with narrowing scope, are “hominoid”, “hominid” and “hominin”. Current usage seems to apply most to aliens who look like us. That is, they’re bipedal, have arms and hands with opposable thumbs, binocular vision using forward-facing eyes in a separate head and horizontal mouths. They may or may not have hair. In fictional contexts, they probably turn up for two reasons. One is that if cinema, stage plays or TV programmes are involved, most actors are human (not all – dogs, cats and dolphins among many other species are also used as actors), so it’s impractical to use models or CGI for the most part unless animation is involved generally. Three-quarters of ‘Star Wars’ protagonists are human, for example. The other is that humanoids are easier to relate to and to write convincingly. This tends to condition people unconsciously to expect aliens to be humanoid. And there is an argument that they would be. Several separate ones in fact.

Suppose there are 600 million life-bearing planets in this Galaxy, and that 500 000 of them have intelligent civilisations originating on them – I should say “habitable worlds” incidentally because it’s easily possible that many of them would be moons rather than planets. In order to represent those numbers in binary form, twenty-nine and nineteen bits respectively are needed. Assuming, very simplistically, that evolution consists of a number of steps with binary outcomes and that there is always intelligent tool-using life at some point, this would mean that twenty-nine steps would be enough to ensure an unique path to intelligent life, and that nineteen steps were involved in producing each species of this type which currently exists. These assumptions should illustrate that the probability of humanoid life is very small. However, the outcome of evolution is not random, and many steps may have to be taken in a particular direction rather than another to lead to a successful species.

The evolutionary biologist Stephen Jay Gould once pointed out that at a certain time in the early Cambrian, the most successful phylum of animals was the priapulids, and that only one species of chordate (the phylum of which vertebrates form the majority of species) was known from that time. There was also a huge variety of other phyla most of which quickly died out. Looking at those representatives of animal life on this planet, most people would probably have bet on the priapulids as the most diverse and perhaps successful phylum later in the history of life. In fact, at the time of writing there were only eight known species of priapulid surviving and they constituted the very smallest animal phylum. There are now twenty-two known species of priapulid and sixty-five thousand known species of chordate, mainly vertebrates. The most diverse phylum of all is of course the arthropoda, with up to ten million species, mostly insects. I already went into why chordates might be rare even in a Universe where complex life is common. Vertebrates are unique in having a hard endoskeleton which facilitates movement. The other major phylum with such a skeleton is the sponges, and they use them to anchor themselves in place and they work as a kind of scaffolding. By contrast, animals with hard exoskeletons are very common, including for example the arthropoda and many molluscs. The specific combination found in vertebrates, including bilateral symmetry, gill slits, a spinal column, hard endoskeleton, a tail extending beyond the anus and discrete muscles, is unique. In fact each feature is quite rare except for bilateral symmetry, although some are found in other deuterostomes, the superphylum whereof we are members, distinguished by developing a mouth after an anus embryonically and having cells whose fate is not fixed early and which divide radially rather than in a spiral arrangement.

Given the success on this planet of other body plans, the arthropods seem more likely to resemble complex animal life elsewhere. Not only are they the majority of species here, but also they have features which have evolved independently several times such as possession of a hard articulated exoskeleton. However, just becausethe basic plan of the body is different, it doesn’t mean these very different animals wouldn’t be humanoid. If silicon-based life is possible, it could even go as far as having completely different biochemistry and still being humanoid if that’s dictated by evolutionary pressures in the right way.

There are some body shapes which seem to recur a lot. For instance, it used to be thought that there was a single phylum known as the polyzoa, which consisted of colonies of sedentary animals, but it turns out that there are two more or less unrelated phyla which happen to be somewhat similar: the entoprocta and ectoprocta, distinguished by the position of their ani inside and outside their feeding organs. Flower-like organisms are also a repeating theme all through the animal, plant and protist kingdoms, although it’s hard to imagine such an organism being intelligent. Why should it be? It does what it needs to do. However, the humanoid body form may not be repeated at all closely throughout the animal kingdom. I think of ants as very slightly humanoid, but it’s a stretch even with them. Nonetheless, it’s possible.

If there is an organised and peaceful galactic community out there, it’s possible that they would send delegates we could relate to, and if they have a wide choice of different life forms because, say, they have half a million such civilisations to select from, it seems plausible that they would choose the most human-like species available. This is a highly fanciful scenario of course, based on serious projection onto a blank canvas, but just maybe, if that situation exists, the first aliens we meet might be highly unrepresentative in that they look somewhat like us. For that to happen, it’s more likely that such aliens would be from a world which was particularly suitable for the evolution of humanoid life, and one major feature of such a world would be bipedal organisms. Bipeds have evolved separately on our planet, notably as dinosaurs and their subset, birds, and also as such forms as kangaroos, gerbils and the now extinct leptictids. All of these, however, have long tails balancing their bodies and none stand erect. An animal with a neck is also “strangleable”, i.e. it has a large number of vital supplies relatively unprotected stretching from the trunk into the head, and it might make more sense either for the brain to be buried deep inside the body or for it to have no neck and instead more eyes and ears arranged around the head, or of course both. The fact that bipedalism usually seems to involve some kind of tail also naturally requires a tail to exist, and the evolution of such an organ seems improbable as it’s only happened once and even then has some tendency to become reduced or disappear. Human erect posture is a combination of three trends, including a change in the position of the pelvis, hip joints and spine, and seems to be unique, on this planet anyway. But the appearance of erect bipedalism has various consequences for anatomy, such as foot-like feet, so to speak, and in the case of vertebrates a head which is placed in a particular position on top of the spine rather than in front of it, which changes the location of the foramen magnum, and there seem to be good reasons for erect bipedalism such as the ability to look out for potential predators and the freeing up of the forelimbs for tool use and carrying, which would otherwise have to be done with the mouth. That said, trunks or tentacular lips could do pretty well in this regard, and we’re talking bipedalism as well rather than tripedalism or something else because we’re assuming an animal is bilaterally symmetrical.

Hence I’m prepared to make a compromise here. Humanoid aliens could evolve as one of many suitable body forms for a tool-using intelligence, but are likely to be rare. If the Galactic Federation exists, I can see them sending humanoid emissaries to soften the blow caused by the shock that there is intelligent life elsewhere, but they would have to choose from a plethora of different types of life form to find the one or two other humanoid species in this Galaxy. And of course this all assumes that the massive array of filters between an initially lifeless world and the existence of a technological culture can be negotiated by the average biosphere.

But there is another possibility here which is fuel for paranoia and delusion, and would undoubtedly be within the capabilities of advanced alien technology: they might be able to produce beings indistinguishable from humans artificially in some way. They could possibly 3-D print them or genetically engineer them with identical genomes to our own, and perhaps implant memories so that even the beings themselves had no idea of their origins. I’m inclined to discount this possibility simply because it constitutes a mental health hazard, regardless of its plausibility, and in a way it’s unscientific because it would be in principle hard to falsify, since they would’ve made sure of that. It is, however, one solution to the Fermi Paradox: some of us are aliens but we don’t know it. Alternatively, maybe some of us are aliens and we do know it, or we’re like this:

I suppose there are a few things to say about this. Firstly, we don’t even know there is any life at all off this planet, barring the few tardigrades which accidentally ended up elsewhere and are currently dormant. Secondly, if anything did ultimately end up getting through all the obstacles and reached the stars, we can safely assume that it would have the technology to do this, and for all we know there are sleeper agents in the human population right now who don’t even know they are themselves. Thirdly, however, this is exactly the kind of thing someone who has lost contact with reality would think, and it plays into, for example, Capgras Delusion. It’s equally possible that this could reflect back on the person themselves and they could end up believing they are such an individual. But the question of motive does arise.

To conclude then, humanoids come up in at least three ways in our understanding of the Universe. One is in the form of robots, where one might question why they would need to be humanoid at all. Another is as aliens, which seem at first to be improbable, or perhaps inevitable, so I’ve chosen the middle way and concluded that if intelligent life is common in the Universe, humanoid aliens are rare but do occasionally evolve. Finally, there probably isn’t anything which would stop non-humanoid aliens from manufacturing humanoid replicas who don’t even know themselves that they aren’t human in origin, but there would have to be some motive for them to do that. Then again, they’d be aliens so maybe we can’t even understand those motives.