Is the ETH a Scientific Hypothesis?

Peter Rogerson
Magonia 65, November 1998

There are disagreements among philosophers and scientists as to exactly what constitutes a scientific hypothesis, but the general consensus is that scientific hypotheses should yield specific, testable, predictions; thus if hypothesis A is correct we would expect an experiment to yield, or to observe in nature B, C and D, if however the experiment yields, or we observe in nature X, Y or Z, then the hypothesis is unlikely to be true.

The hypothesis should lead to specific conclusions, the universe, or some aspect of it should be an observably different place if the hypothesis is true, than if it is false.
A well known example of a hypothesis which is not a scientific hypothesis, because it leads to no testable conclusions, is the one invented by the Victorian geologist Philip Gosse, who sought to reconcile the growing evidence for the great age of the earth, with his personal belief in the Biblical account of the creation of the world in 4,004 BC. His answer was to argue that the prior history of the earth existed as an idea in the mind of God (as virtual reality, as we would say today). The world went through cycles of development, and at some point in 4,004 BC this virtual world was manifested by God, complete with the record of its previous virtual history such as fossils in the ground and Adam and Eve’s navels (and presumably their memories of non existent parents). Clearly such a hypothesis leads to no different conclusions that one in which the world really existed for vast ages.

Also scientific hypotheses should lead to further questions, they should not end with question stopping answers such as “that is the way God wills it, it is not for us to question why”, or because boggarts cause it. (Why does sodium when placed in water fizz and spit – because the boggarts make it so). In other words they should not invoke supernatural forces, or arbitrary wills, whether that of God, or lesser supernaturals such as angels or devils. That explains everything, and therefore nothing.

It is here that the ETH in its most general form clearly falls, in the absence of any independent knowledge as to the nature and capabilities of ETs, ufologists feel free to invest them with any properties they choose, often self contradictory ones. If it suits the case for the ET’s to come in fallible machines which repeatedly crash in the New Mexico desert, then they will ascribe that property to them; if it suits to grant them near omnipotent supernatural powers, for example enchanting whole cities while abducting people through solid walls into invisible space ships, they will gladly do so. If the UFOs behave like conventional machines, then the evidence of exotic machines proves the ETH; if they behave like something else entirely then this also proves the ETH, because, of course no-one is naive enough to believe that they could come here by any kind of machine or process which we are familiar. It’s clear that wherever the evidence leads, proponents of the ETH will find confirmation for their belief it ETs.

Not surprisingly, Jerome Clark, for example, has never responded to my challenge as to how he would go about refuting the ETH. The only way that could be definitively be done, would be to search every planet in every solar system in the entire universe for signs of life, and even then if none were detected proponents of the ETH would say that was because the ET’s had camouflaged themselves so well, or because they were the wrong vibrational level for our instruments.

This does not mean that no version of the ETH can ever be a scientific hypothesis; however unlikely. The hypothesis that UFOs are fusion powered spaceships from Mars is a scientific hypothesis. We could work out in advance what the properties of fusion powered spaceships are likely to be, and compare them with unexplained UFO reports (there is a problem there we will come to later), and eventually go to Mars to look. In other words the hypothesis stands a chance of leading to specific conclusions, and one can devise a finite, once and for all, test.

How general can the ETH be made and still be a scientific hypothesis? At the very least we have to limit the ET’s, however advanced their technology, to the currently understood laws of physics, and I think we have to make the assumption that the ET’s are in very general sense, somewhat like us. They have manipulative organs, and the equivalent of a complex, highly developed form of consciousness. Make these two assumptions, in order to make the ETH at least somewhat manageable, and something interesting happens. It does not predict UFOs, predicts that it is more likely than not that if ET craft carry biological beings, they will be very, very big indeed, but if they are mechanised they are more likely than not to be very, very small indeed.

How can make such a prediction? Note that I said we have to say that the ET’s are roughly like human beings and that statements made about human interstellar flight apply to them also, and that we denied them any mysterious Z-process. This means they can’t go faster than light, so all journeys take a very long time. This means that whatever means you use, explicitly or implicitly you are sending your astronauts into permanent exile.

There are three main methods suggested by which human beings might reach the stars. The first is the space Ark, this travels at moderate speeds, but takes huge amounts of time to reach its destinations. Generations pass on the ship before star-fall, there is no return. This is a route for permanent colonies only. The Ark therefore has to be huge. Remember this is not just a colony which must sustain itself for ten or so generations of travel, but must establish a long term breeding programme at their destination. A minimum population to establish a wide enough genetic mix, to guard against future disease, population crash, etc., is probably in the region of 10,000 people.
Some other points must be borne in mind. These people would have to be given space, a colony divided into separate villages seems more sustainable than some giant apartment block. They would have to take a sustainable biosphere; we simply do not know how bound up with the general biosphere human beings are, how simple things like the cl-mate, the seasons, the alternation of night and day, the tides, etc., affect us. Remove us from the earth for long periods of time, and viability cannot be guaranteed. It seems a whole artificially biosphere would need to created. We are thinking of ships many kilometres long.
No human society ever before would have gone into such a permanent exile, with not even the wildest, fondest dream of return
In any case it is not at all clear that such a voyage could ever succeed. For a start could any sane human society ever permit any group of people to make a totally irredeemable choice on behalf of unborn generations to come? Even if the voyage got under way the psychological problems seem overwhelming. No human society ever before would have gone into such a permanent exile, with not even the wildest, fondest dream of return. No human society before would become so enclosed, locked in with themselves, unable to escape. What sort of people might be initially attracted to the ideas of being pioneers among the stars? The restless, the adventurous, the derring-do, precisely the sort of people who would eventually find being cooped up into the space Ark, even one a couple of hundred kilometres in diameter, unsustainable. Their world might become enclosed on itself, abandon its original project, or, I suspect, collapse in personal and factional feuds.

If the space Ark is not a very pleasant prospect, then what of the two touted alternatives: some kind of artificial hibernation, or very very fast relativistic voyages, taking advantage of the time dilation effect? Though it may seem these offer the chance of voyage and return within the lifetime of the crew, in reality these too offer a subtler form of irrevocable exile, the world to which they return if they choose to return, will be one transformed beyond recognition, all friends, family, familiar landscape, gone, all social mores changed, the language transformed. Returnees would indeed be strangers in a strange land. If ETs have the sort of complex level of consciousness needed to build spaceships, then, because it seems that consciousness has at least in part of evolved as a means of dealing with social interaction, the ETs will be as embedded in their society as we are in ours, capable of feeling their equivalent of pain, loss, loneliness and bereavement.

This means that whether there is a planned return or not, a small crew is out, you would have to send a social support network, capable to sustaining the voyage and creating a society within a society on return. Given the vast changes on return, why return? The relativistic or cryogenic spaceships are likely also to be colony ships, with vast crews and no plans for return. It should be borne in mind that even relativistic spaceships will take crew-time voyages of several years: it takes time to accelerate and decelerate.

Furthermore, very, very, very fast voyages are probably not possible. This is because the discussions on ultra fast flight, say 99.99% of the velocity of light, are based on idealised models in which interstellar space is an absolute vacuum, but this is not the case; there is gas, fine dust and no doubt small lumps of rock out there. Of course the density from the view-point of a static observer is very low, but from the point of view of traveller close to the velocity of light, the distances ahead are increasingly foreshortened; the faster the ship, the greater the density of the interstellar matter, and, from the ships point of view, the greater the mass of its components. At these high speeds, impact with something the size of a grain of sand, would breach the hull, anything the size of a pea, blow it to smithereens. Not only that, the foreshortening of the incoming space, means the wave-length of incoming light will be increasingly shortened. As the ship gets ever closer to C, the incoming light will blue shift into the ultraviolet, then into hard X-rays. The crew will fry. What relativity gives with one hand, it takes with the other. This leaves out the stupendous energies which would be required to accelerate the ship to velocities close to C, as the ships mass (from the viewpoint of an external observer) is ever increasing.

All of this suggests than neither slow nor very fast space-ships are a practical proposition, if human beings are to go to the stars, it will be in fast (say 25 per cent to 75 per cent of C ) but not ultra fast, very big ships, with founding populations in the many thousands. If ET’s are anything like us at all, it is more likely than not they are coming in something very big indeed. If UFO reports are generated by biological ETs they must have a very big base somewhere in our solar system. No-one has detected one so far, nor do we see daily spaceships visiting us.

If however, we go for unmanned probes, then the priority is speed, in order that we can get the information from the probe in as short a time as possible. The route is as obvious as possible, An unmanned interstellar probe should be as cheap, and small and fast as technology will permit. Indeed the major limit here may be finding a way of decelerating the probe at the other end, though use of friction with interstellar dust might work. Launching would be using some process which does not use on-board fuel, firing from laser cannons, or using some vast linear accelerator (on the Moon perharps). How small these probes can get will depend on advances in computer technology, but my guess is that they could get pretty small. Once that path is taken both the costs and risks will be some many orders of magnitude less than manned voyages that the manned voyage route will never be taken. If ET’s are anything like us, it is not likely they will send biological beings on interstellar voyages.

The problem with the ETH is now clear. The ideas underlying much of the speculation surrounding it are already old fashioned by our own science.

The problem with the ETH is now clear. The ideas underlying much of the speculation surrounding it are already old fashioned by our own science. The ETH was formulated in days when spaceships, (always thought to come from Mars) were seen as kinds of ultra high performance aircraft, before ultra high resolution satellite surveillance, before the computer revolution, before miniaturisation. If real ET’s were visiting us, we would probably never notice.

It may be argued that that all of this is very anthropomorphic, that real ETs may be very different from us, that they come here using processes which we cannot understand. There could be a lot of truth in that, but supporters of the ETH must understand that the moment they invoke unguessable psychologies and exotic technologies about which we know, and can therefore say nothing, they are abstracting the ETH from the realms of science, into those of metaphysics and personal faith.There is another difficulty which would face proponents of an ETH even if they could state in advance what the properties of the ET craft were, so as to compare them with UFO reports; this is that there is no agreed upon, uncontaminated data base of UFO reports.
Indeed as the definition of UFO is essentially a negative one, those reports as of today not yet identified, there can be no guarantee that the reports will not be explained tomorrow, (remember Peter Day’s film) There are no UFO reports which are wholly different from all IFO reports. There is furthermore no reason to suppose that even if (as might well be the case) that there are UFO reports generated by novel phenomena, they all have the same cause. As I found out while compiling the notorious INTCAT, there are few cases which everyone agrees on. There would also be the problem of determining whether an equal or better fit might not be made with some other phenomenon in the future.

As I have noted several times before, there is an even bigger problem with the ETH. Its central proposition may be just too anthropomorphic; the belief that there are ETs who are in essence people of another shape, perhaps looking different from us, but who are engaged in essentially the same projects. The occupants reported as being connected with UFOs are just too human, and there is a large measure of agreement among evolutionary biologists that there is little chance of human beings evolving elsewhere. Indeed if human beings were wiped out tomorrow, there is almost no chance of them evolving on earth again.
At this point there is a tendency among some Ufologists to cry parallel evolution; what these people forget is that parallel evolution is something which occurs when creatures having different immediate ancestors, (but like all terrestrial organisms sharing a good deal of common DNA coding), adapt to very similar ecological niches. This has not happened in the case of upright walking, tool users. There are no marsupial people, there are no New World people, there aren’t any people descended from the orang-utans. The best parallel evolution might come up with is some ET equivalent of a nondescript little furry animal, Unless one makes the assumption that the presumed ET world has ecological niches virtually identical to our own, even that might be asking too much. As most women who have given birth, and as anyone who suffers from back problems will tell you, the human body is not particularly well adapted. Large-headed upright walkers are not likely to be widespread. And as for the Mekon-like entities so often reported, they are even less likely. How do they give birth? How could a small heart in a small body supply enough oxygen to such a large brain.

Could creatures physically very different from us be sufficiently mentally similar to us to build radio telescopes and space ships? It has to be remembered we are not just talking about creatures which are anatomically different from us, such as elephants and pangolins, but physiologically and possibly even biochemically different. It is by no means clear that they would be composed of DNA, as opposed to some other complex reproducing molecule, which had evolved in the specific circumstances of their primal ooze. These would be entities who genetically would be far more different from us than yeast is. When, as I noted a few issues back, we realise than a very tiny genetic mutation in our own species can produce a major transformation of consciousness, it seems very improbable.

Perhaps this would be the next Copernican revolution, not to see ourselves as being of such cosmic importance that the universe would be somehow bereft if not filled with us or our surrogates, but to accept ourselves as one unique species among many, on one unique biosphere, in a universe of unique biospheres and unique entities. (We don’t seem to have any problem in facing up to the fact that we are not likely to live in a universe filled with armadillos and kangaroos). That our ability to build radio telescopes would be no more or less surprising that the unique nature of any other unique species abilities.

We also have to realise that the idea of building radio telescopes and space ships is not just unique to our species, among all the hundreds of millions which live or have lived on earth, it is unique to ours alone among many thousands of human cultures past and present. ET’s wouldn’t just have to think like humans, they would have to think like twentieth century Euro-Americans. The ET/CETI proponents don’t just regard all other species as being somehow irrelevant, all other human cultures and human achievements are tossed aside as being of no importance.

As evolutionary history shows that the coming of human beings was not an inevitability, so history shows that the coming of heavy industry was by no means inevitable. The merger of science and technology appears to have been the result of something specific about western European culture, possibly a merging of Greek notions of rationalism, with Irano-Judaic notions of the linearity of history, the existence of a common culture and lingua franca (Latin) in the absence of a centralised political authority, as well as notions of individuality, the relative lack of affluence and comfort in the ruling class, amongst other factors. One can say with some confidence that many of the other cultures depicted in Star Trek, say, as having space travel, in reality would be most unlikely to develop techno-scientific heavy industry.

Of course proponents of the ETH can argue against all of these points, and I would be the first to agree that in our state of such profound ignorance (we don’t even know that there are any extraterrestrial life forms) there can be no certainties. But it is precisely for that reason that the ETH, while by no means wholly irrational to hold as an article of personal faith, is not and cannot be a useful scientific working hypothesis.

See also: Saucers and Science: where did it all go wrong? by John Harney.