FROM CYBERSPACE TO OUTER SPACE

with two million other people, in a search for extra-terrestrial life

I WAS in an Internet café in Reykjavik recently which had three personal comput- ers at which people, for a small fee, could send and receive emails. But, when no one was using them, these computers were not idle. They were searching for signs of alien civilisations in space.

Belief that ours is not the only civilisation in the universe shows no signs of abating. Why should it? Only last month astronomers were greatly excited by the news that 12, or maybe 13, new planets had been discovered, bringing to more than 60 the number of planets known to be circling stars in the galaxy. Most of them, of course, are huge gaseous worlds such as Jupiter and seem totally inhospitable to life. These are the only planets known to us because we don't yet have the technology to find smaller alien worlds.

But the time will come, perhaps within decades, when we will have telescopes capable of finding thousands of planets the size of Earth. Some may prove to be worlds at suitable distances from their par- ent suns — neither too hot nor too cold on which advanced civilisations may have evolved.

Might some of these civilisations be sending out radio signals to advertise their presence? To find out whether this is the case, a vast computer experiment has been started. It involves the biggest single com- puter network in the world, with a com- bined speed three times greater than the world's fastest supercomputer.

The experiment costs virtually nothing. More than two million privately owned personal computers around the world are being used, when they are idle, to search for artificial signals among the trillions of bytes of data being collected by the giant radio telescope at Arecibo, Puerto Rico.

I have joined the search myself, and any- one is free to do so. You don't pay or get paid for doing it. All you can hope for is the prospect of everlasting fame if your comput- er should be the one that finds the tell-tale signal from ETs or 'little green men' as some scientists call them. The chances of this hap- pening are, of course, about the same as those of winning the Lottery twice a week for a month, but about 170,000 Britons are engaged in the search. To join in, simply click on to the web address http://setiathome.ssl.berkeley.edu/ and 'open an account'. The key word `setiathome' (or Seti for short) stands for the Search for Extraterrestrial Intelligence at Home.

Processing a block of data from Seti typi- cally takes about 15 hours of computer time. A flashing light at the bottom of your screen tells you when it has finished. At this point your machine automatically emails your results to astronomers at the Universi- ty of California who send you back a new block, and off you go again.

Will the search ever succeed? The fact is that nobody has the faintest idea whether the universe is inhabited, and one opinion on the question is as good as another. The science of 'exobiology' (the search for life beyond Earth) is unique among the sci- ences for having absolutely no data. To some scientists the fact that aliens have never visited us is proof that they do not exist. But others are convinced by the almost unimaginable number of stars in the universe — one followed by about 22 noughts — that other civilisations must exist somewhere.

So far, no one has established beyond reasonable doubt that any life, however primitive, either exists or has ever existed elsewhere. It is still hotly debated whether an Antarctic meteorite contained traces of a billion-year-old organism from Mars, as was claimed three years ago, and this mat- ter may never be resolved.

True, the universe is filled with the `building blocks of life', complex com- pounds of carbon, oxygen molecules and water. But these are only the chemicals on which life depends, not life itself. And so the search goes on. Apart from the radio survey, there are plenty of ideas about where to look for life, even within our own solar system. Jupiter's giant moon Europa, for instance, is believed to have a vast ocean thinly cov- ered by ice. Why else would this moon be pale blue? It is perfectly reasonable to sup- pose that this alleged ocean, stirred daily by Jupiter's tides, contains sufficient nutri- ents to nourish life. And so people are seri- ously talking about building a submarine that will explore it and find out.

Until the 20th century's space probes ventured to our local worlds and found them barren, many people believed that the universe teemed with life, both intelli- gent and brutish. Otherwise, what would have been God's purpose in creating it? The scientific historian Michael Crowe described the Victorian viewpoint:

From Capetown to Copenhagen, from St Petersburg to Salt Lake City, terrestrials talked of extraterrestrials. Their conclusions appeared in books and pamphlets, in penny newspapers and ponderous journals, in ser- mons and scriptural commentaries, in poems and plays, and even in a hymn and on a tombstone. Oxford dons and observatory directors, sea captains and heads of state, radical reformers and ultramontane conser- vatives — all had their say.

So what shall we do if the search suc- ceeds? Since the aliens we find will neces- sarily be more advanced than we are because they will have the ability to trans- mit intelligible signals through the vastness of space — an obvious thought is that sci- ence can be abandoned. What would be the point of continuing to search for knowl- edge if it can be obtained from beings much more advanced than ourselves? You have a question about the meaning of exis- tence? Just send them an email.

The only snag with this is that it might take centuries to get a reply. For, since radio messages can travel only at the speed of light, one would take four years to reach us from the nearest star and 100,000 years from the furthest star in our Milky Way galaxy. And so communicating with ET could be an age-long endeavour. Send a message, and your great-grand- children can look forward to getting a reply. And it's no use sending a text mes- sage either, since ET will be ignorant of all our languages. Better to imitate the ancient Egyptians and send pictures, in the form of binary code. A clever arrangement of pictures can contain a great deal of information.

But suppose a common text language is somehow created. Then beware: a message could have a sinister hidden meaning. What if aliens say their only wish is to `serve mankind'? That might mean what it says, or, as H.G. Wells once remarked, that they were 'wondering whether to serve us fried or baked'.

Adrian Berry is consulting editor (science) of the Daily Telegraph.