SETI: futile effort or noble undertaking?

On national scales SETI has never cost a great deal; the money we have spent on it would just about pay for a nuclear submarine.

There are two questions that are of supreme interest to everybody. One: just how did the Universe come into existence? And two: are there intelligent beings on other worlds? The first of these problems is frighteningly difficult to answer; we may never be able to do so satisfactorily – but given enough perseverance, combined with good luck, the second might be answered tomorrow.

In writing this comment, I am well aware that I am stressing my own personal opinions and that many people will disagree with them, but I don’t really see what else I can do, because we have so little to guide us on this subject. SETI, the Search for Extra-Terrestrial Intelligence, is no longer ridiculed in the way it used to be only a few years ago.

However, we still have what can be called the ‘giggle factor’, and the flying saucer and UFO enthusiasts do tend to make people regard the whole subject as science fiction. But is SETI true science, and if so, is it worth the expenditure of appreciable sums of money, quite apart from the time spent on it by busy researchers?

We are handicapped from the outset, simply because we have no proof of the existence of life anywhere except on the Earth. There are some eminent thinkers who maintain that there is no extraterrestrial life (hereafter referred to as ET), let alone intelligent life.

Their arguments are mainly religious, and I will go no further down that road, because I am not qualified to do so and would almost certainly take a wrong turn. However, there are scientific arguments too, based usually on the admission that life is too complex to appear very often.

Mars holds the key

The key here may be provided by Mars, which is now a hostile place for life of our kind, but which used to be much more welcoming, with broad oceans and presumably an atmosphere thick enough to ward off dangerous radiations. Within a few years, we ought to know whether there are any signs of life, either past or present. If there are, then surely we must agree that life will appear on any world where conditions are tolerable, and will evolve as far as its environment allows.

This is only a start, because the appearance of life is no guarantee that it will ever develop intelligence. Here again, we can do little more than speculate, but we do at least have the example of life on Earth, and what happened here can presumably happen elsewhere. Otherwise we are saying that Earth is a special case, which is both arrogant and unjustified.

Look at it this way: our Galaxy contains 100 million stars and we have found that planetary systems are common; there must be many millions of worlds similar to Earth. Beyond, there are millions upon millions of other galaxies, each with its quota of stars and planetary systems. To me, it seems absurd to suggest that in all this there are no other sentient beings. I may be quite wrong; decide for yourself.

So for now, humour me and assume that there is widespread ET in the Galaxy. We won’t find it in the Solar System, except (possibly!) on Earth, so we must look further afield. The obvious way of establishing contact is by means of radio. The first attempt was made as long ago as 1960, when Frank Drake and his colleagues used the 25m radio telescope at Green Bank, West Virginia.

Listening for a rhythm

They ‘listened out’ at selected frequencies in the hope of picking up rhythmical signals from astronomers living on planets in the systems of two relatively nearby stars of essentially solar type: Tau Ceti and Epsilon Eridani. Not surprisingly the results were negative, but at least the choice of targets was sensible.

True, Tau Ceti turned out to be a disappointment, but Epsilon Eridani definitely has several planets, and there may well be a member of its family that would be suitable for us. Since then, there have been many other attempts involving other stars, but as yet – no luck.

We have also sent out messages, hoping that they will be picked up and answered. They are naturally mathematical (I doubt whether even the most erudite Epsilon Eridian would understand English, let alone Chinese!), and quick-fire repartee will always be difficult, because we are dealing with such vast distances.

Send out a signal to a star 15 lightyears away in 2007 and the signal will arrive in 2022. If a helpful operator replies at once, his message will be received back on Earth in 2037. All SETI would show is that ET really does exist. Even so, this would be the most important discovery of all time and it would revolutionise all of our thinking.

Travel to distant stars

At present, we have no idea of how to achieve travel to other planetary systems, and by any method known to us, I doubt whether it can ever be done. We need a fundamental breakthrough, which may come this year, next year, in a thousand years – or never.

Thought-travel and teleportation are pure science fiction today – but remember, television and even radio would have seemed equally outlandish to King Canute, and we may be as close to teleportation as Canute was to EastEnders.

Unless we achieve something quite beyond today’s science, we must be content to stay in the Solar System. Yet other civilisations may well be far in advance of ours and capable of interstellar flight.

I have heard suggestions that we should avoid trying to make contact with ET, because of the danger that some alien races might decide to come here and conquer us (or in modern political language, ‘liberate’ us). I find this irrational, because any race able to reach us would long since have outgrown all forms of warfare and could teach us a good deal.

My view – and I repeat that I know others will disagree – is that SETI is well worthwhile. On national scales it has never cost a great deal; the money we have spent on it would just about pay for a nuclear submarine.

Even if I am right in assuming that ET is widespread, we can’t tell when contact will become possible, but this is no reason to abandon the search. Unless we keep trying, there is no hope of success.