by Isaac Asimov

9. Little Green Men or Not?

When most people think about flying saucers or, as they are more austerely called, "unidentified flying objects" (UFOs), they think of spaceships coming from outside Earth and manned by extraterrestrial intelligences. Is there any chance of this? Do the "little green men" really exist? There are arguments both for and against, pro and con.

Pro. There is, according to the best astronomical thinking today, a strong chance that life is very common in the universe.Our own galaxy is only one of perhaps a hundred billion, and our single galaxy has over a hundred billion stars in it. Current theories about how stars are formed make it seem likely that planets are formed also, so that every star may have planets about it. Surely some of those planets would be rather like our Earth in chemistry and temperature. Current theories about how life got its start make it seem that any planet with something like Earth's chemistry and temperature would be sure to develop life. One reasonable estimate advanced by an astronomer was that there might be as many as 640 million planets in our galaxy alone that are Earth like and that bear life. But on how many of those planets is there intelligent life? We can't say, but suppose that only one out of a million life-bearing planets develop intelligent life-forms and that only one out of ten of these develop a technological civilization more advanced than our own. There might still be as many as one hundred different advanced civilizations in our galaxy, and perhaps a hundred more in every other galaxy. Why shouldn't some of them have reached us?

Con. Assuming there are one hundred advanced intelligences in our own galaxy and that they are evenly spread throughout the galaxy, the nearest one would be about 10,000 light-years away. To cover that distance by any means we know of would take at least 10,000 years and very likely much longer.Why should anyone want to make such long journeys just to poke around curiously?

Pro. It is wrong to try to estimate the abilities of a far-distant advanced civilization, or their motives either. For one thing, the situation may not be average. The nearest advanced civilization may just happen to be only 100 light-years away, rather than 10,000. Furthermore, because we know of no practical way of traveling faster than light doesn't mean an advanced civilization may not know of one. To an advanced civilization a distance of 100 light-years, or even 10,000 light-years, may be very little. They may be delighted to explore over long distances, just for the sake of exploring.

Con. But even if that were the case, it would make no sense to send so many spaceships so often (if we are to judge by the number of UFO reports over recent years). Surely we are not that interesting. And if we are interesting, why not land and greet us? Or at least communicate with us without landing. They can't be afraid of us, since if they have advanced so far beyond us they can surely defend themselves against any puny threats we can offer. On the other hand, if they want to be merely observers and don't want to interfere with the development of our civilization in any way, they should surely so handle their observations that we would not be continually aware of them.

Pro. Again, we can't try to guess what the motives of these explorers might be. What might seem logical to us might not seem so logical to then. They may not care if we see them, and they also may not they also may not care to say hello. Besides there are many reports of people who have seen the ships and have even been aboard. Surely some of these reports must have something to them.

Con. Eyewitness reports of actual spaceships and actual extraterrestrials in themselves, totally unreliable. There have been innumerable eyewitness reports of almost everything that most rational people do not care to accept-of ghosts, angels, levitation, zombies, werewolves, and so on. What we really want, in this case, is something material; some object or artifact that is clearly not of human manufacture or earthly origin. These people who claim to have seen a spaceship or to have been inside one never end up with any button, rag, sheet of paper, or any other object that would substantiate their story.

Pro. But how else can you account for all the UFO reports? Even after you exclude reports that are incomplete or mistaken, that are gags or hoaxes, there still remain a large number of sightings that can't be explained by scientists within the present limits of knowledge. Aren't we forced to suppose these sightings are extraterrestrial spaceships?

Con. No, because we have no honest way of saying that the extraterrestrial spaceship is the only remaining explanation.
[For the same reason,one cannot presume God is the only explanation if one manages to refute evolution,and so in lieu of another explanation God is not the default explanation to fall back on -LB]
If we can't think of any other,that may simply be because of a defect in our imagination or in our knowledge. To seize the easiest or most dramatic explanation as the only one left would be foolish. If an answer is unknown. then it is simply unknown. An Unidentified Flying Object is-unidentified.

The most serious and level-headed investigator of UFOs I know is J. Allen Hynek, a logical astronomer who is convinced that the UFO reports (or some of them, at least) are well worth serious investigation. He doesn't think that they represent extraterrestrial spaceships but he does suggest that they represent phenomena that lie outside the present structure of science and that understanding them will help us expand our knowledge and build a greatly enlarged structure of science.
He even thinks that the advance brought about by solving the UFO riddle could be so enormous that it would represent a "quantum jump" in some totally unexpected direction. Well, perhaps; but that is only what he believes. He has no serious evidence to back his belief. The trouble is that whatever the UFO phenomenon is, it comes and goes unexpectedly. There is no way of examining it systematically. It occasionally impinges on some of us and, more or less accidentally, is partially seen and then more or less inaccurately reported. We remain dependent on nothing more than occasional anecdotal accounts. Dr. Hynek, after a quarter of a century of devoted and honest research, so far has ended with nothing. He not only has no solution, but he has no real idea of any possible solution. He only has his belief that when the solution comes it will be important.
He may be right, but there are at least equal grounds for believing that the solution may never come or that, when it comes, it will be unimportant.

Is there anyone out there?

FOR CENTURIES, humanity has been intrigued by the possibility that we are not alone. The prospect of alien beings on a distant planet has fascinated not only science fiction fans but also some of the most brilliant philosophers and physicists. Yet despite increasingly powerful telescopes to scan the skies, and super-computers to search the airwaves for radio signals, the hunt for extraterrestrial intelligence has so far proved fruitless. Hardly surprising, you might think. After all, don't alien creatures owe more to Hollywood fantasy than scientific reality? Well, not according to the laws of probability. In the summer of 1950, a group of physicists sat down for lunch in the New Mexico town of Los Alamos. They included Professor Enrico Fermi, Nobel laureate and inventor of nuclear power. Fermi asked his companions if they had any idea why Earth had not been visited, or at least contacted, by aliens from space. 'Where is everybody?' he asked. His question has been dubbed Fermi's Paradox. Now, in the most intriguing book ever to deal with Fermi's Paradox, Dr Stephen Webb, a British physicist and writer, has come up with 50 possible solutions to a quandary that has bemused scientists for more than half a century. He rejects 49 before coming up with his own, startling conclusion. For while it is tempting to dismiss the idea of 'little green men' as preposterous, most scientists agree that intelligent aliens must surely exist, even If there is no evidence. This rather surprising conclusion is inevitable, they say, for two reasons. First, the universe is incredibly large. There are as many stars as there are grains of sand on all the beaches of Earth. The chance of life evolving in only one place - Earth alone - is seen as impossibly Secondly, the universe is so ancient - some 12 billion years old - that if aliens have evolved, it is logical to assume that most will be far more advanced than humanity, which has made significant technological leaps only in the past century or so. Thus the laws of probability dictate that not only are aliens out there, but also that they must be hugely advanced compared with our own civilisation. Surely, therefore, some of them would have visited us by now. This is the problem that Professor Webb has addressed. He begins by tackling the suggestion that aliens are here on earth at the moment, or at least have visited us in the past. Alleged sightings of flying saucers abound. Some several hundred thousand Americans even claim to have been abducted by aliens and taken aboard their spacecraft. Surely not all these witnesses could be mistaken or lying? Sadly says Dr Webb, they almost certainly are.The vast majority of UFO sightings have perfectly rational explanations - weather balloons, reflected car lights etc. The rest - the X-Files of popular imagination - nearly always turn out, under careful scrutiny, to be result of fabrication or delusion. As Astronomer Royal Sir Martin Rees points out: 'I think it unlikely that if they (aliens) come here, they would just despoil a few cornfields or abduct a few well-known cranks.' Similarly claims that aliens have visited us in the past do not stand up to close examination. In the 1970s, Erich von Daniken made a fortune by writing books claiming aliens visited us thousands of years ago and that our ancestors had recorded these events in their buildings and works of art. ACCORDING to von Daniken, everything from Stonehenge to the Easter Island statues was the work of aliens. His books contained not one jot of evidence for his eccentric claims, but still sell in their millions. Perhaps, then, aliens are out there, but are deliberately avoiding us it is intriguing to imagine that Earth is being studied from afar by advanced aliens under strict instructions to leave us alone, just as we try to leave animals undisturbed in game parks. This is the 'zoo scenario', first proposed in the 1960s. But as Dr Webb points out, even if such an embargo existed, it is highly unlikely all aliens would obey it. A more rational explanation might be that the universe is home to other forms of intelligent life, but that they simply haven't managed to get to Earth yet. After all, the distances between the stars is immense. At 25,000mph, it took the Apollo astronauts over four days just to reach the Moon; at the same speed, they would have taken tens of thousands of years to reach the nearest star. But most engineers and scientists believe that travelling to the stars, although difficult, is by no means impossible. Even with our current technology we could, if we threw everything we had at the problem, probably build some sort of starship in a few decades or less, powered by nuclear rockets. If there are civilisations millions of years older than ours out there, it is inconceivable that none would have done this. Some scientists have suggested that the reason we neither hear nor see any aliens is that they have all destroyed themselves. They postulate a universal cultural law, which holds that any species that is capable of destroying itself, for example through nuclear obliteration or germ warfare, does so shortly after attaining this capability. This is a depressing idea - for it means that humanity is doomed, and sooner rather than later. But surely if many galactic civilisations do exist, as it is theorised, some of them should be able to avoid Armageddon? Maybe we are simply mistaken in believing that aliens would even want to visit us. The acclaimed American mathematician Vernor Vinge argues that any species capable of building a computer will eventually construct a super-machine so intelligent that it will quickly kill its makers and sit out the rest of eternity in deep thought, not going anywhere. (Alarmingly, Dr Vinge reckons humans will build such a machine before 2030.) But even if Vinge's idea is right, then surely some of these megamachines would want to meet their neighbours? He suggests that machine intelligences may choose to merge with their biological ancestors, thus (presumably) preserving some of their biological curiosity. For every explanation of Fermi's Paradox, it seems there is an equally persuasive counterargument. The non-appearance of aliens remains a mystery. Nevertheless, most scientists have concluded that extraterrestrial intelligence of some form must be a reality. Even Nasa, which used to avoid talking about aliens for fear of ridicule, has now set up an 'exobiology' institute to study the possibility of extraterrestrial life (although the institute's focus is on microbes, rather than little green men). And with each leap in technology; Fermi's Paradox seems ever more puzzling. Instruments like the Hubble Space Telescope have shown the universe to be even more vast than it was thought to be in Fermi's day; the chances that no one is out there are getting more and more remote. So is it only a matter of time before we receive a signal, or even a visitation? Stephen Webb thinks not. His solution to the Fermi Paradox is blissfully simple to comprehend. Unlike the vast majority of his peers, Dr Webb believes that there are no aliens. There is plenty of life out there, he argues, but not the sort of life that builds spacecraft and radio telescopes. Earth, for more than 99.999 per cent of its history, was covered with life, from plants and bacteria to large mammals, but none of it 'intelligent' enough to build even basic technological devices, let alone a means of communicating with extraterrestrial beings. Dr Webb argues that ancient and huge though it is, the universe may well have come up with only one technological civilisation - us. This is because the sequence of events needed to evolve intelligent life is spectacularly unlikely - it takes not only a hospitable planet, but also a planet that avoids cosmic catastrophes and manages to come up with a highly intelligent species. It is easy to imagine that, had the dinosaurs not been wiped out 65 million years ago, then human beings might never have evolved and the Earth would still be ruled by impressive, but dumb, reptiles. Even 150 years ago, there was no civilisation on Earth capable of broadcasting or detecting radio signals from space. In essence, our modern civilisation is a fluke, he argues. It isn't a solution that will convince many, but if he is right, then the philosophical implications are truly awesome. For bizarre though it may sound, the only thing more incredible than finding definitive proof of the existence of aliens would be the discovery that humankind is indeed utterly alone. Michael Hanlon [Daily Mail Dec7 2002] · Where Is Everybody? by Stephen Webb, published by Copernicus Books