• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

IS THAT YOU, E.T? ; As Radio Signals From Space Are Heard, the Astronomer Royal Says, Yes, Aliens May Exist

Posted on: Friday, 3 September 2004, 06:00 CDT

DOES alien life 'exist'?

This is surely one of the most fascinating questions in science and I'm hopeful that, before this century is over, we will have an answer.

Indeed, just this week it has emerged that there are new grounds for optimism. Astronomers at the giant radio telescope at Arecibo in Puerto Rico have recorded, at three separate times, signals that modulate in a strange and seemingly unnatural way, leading to speculation that they may have been transmitted by an alien life form.

Of course, the sky holds many mysteries, and the source may prove to be an unknown astronomical object, perhaps a new kind of star.

Back in 1967, British scientists Jocelyn Bell and Anthony Hewish, using a radio telescope in Cambridge, detected a strange 'beeping' source which they decided could have been transmitted by 'Little Green Men'.

In fact, they had discovered a remarkable new star - significant enough to deserve a Nobel Prize, but far less important than the detection of extraterrestrial intelligence.

The news from Arecibo is fascinating and surprising. But extraordinary claims require extraordinarily strong evidence and I wouldn't yet bet that the discovery of intelligent alien life will follow.

Certainly, we must continue the search because of the import of any manifestly artificial signal for our understanding of humanity's place in the cosmos.

Speculation about aliens is nothing new. In earlier centuries, many believed that the Moon and even the Sun were inhabited.

In the late 19th century, the science fiction of Jules Verne and H.G. Wells further popularised the idea of alien life. Percival Lowell, an American astronomer, believed Mars was criss-crossed by canals, dug by an advanced civilisation to channel water from the frozen polar caps to the 'deserts' near the equator.

In the Thirties, an American radio dramatisation of H.G Wells's War Of The Worlds was so compelling many thought it was a newsflash and that a real Martian invasion had begun.

NOW that probes have landed on Mars and beamed back pictures, it seems a far less hospitable place than it did to our forebears. There can be nothing resembling the 'Martians' of popular fictions - however, there was once a lot of water there, so simple life could once have existed.

But in the vastness of space, we can rule out nothing. Our Sun is just one star among billions. Astronomers have discovered in the past few years that other stars are not just twinkling points of light: they have their own retinue of planets circling around them.

The first of these 'extra-solar' planets to be detected were very big - rather like Jupiter and Saturn, the giants of our own Solar System. It's obviously harder to detect smaller planets but, just last week, three different groups of astronomers reported that they had found several new planets not too dissimilar to Earth.

Could some of these planets harbour life-forms far more interesting and exotic than anything we might find on Mars? Could they even be inhabited by beings we could recognise as intelligent?

We have no idea what intelligent aliens would look like. Of course, it would depend on the habitat that their 'home planet' offered. Here, on Earth, there's an enormous variety of life, ranging from slime mould to monkeys (and, of course, humans as well).

Life survives in the most inhospitable corners of our planet - in caves where sunlight has failed to penetrate for thousands of years, inside arid desert rocks, in the depths of the earth and in the highest reaches of the atmosphere.

Alien habitats could harbour creatures of inconceivably greater variety.

They could be huge, bulbous creatures floating in the dense atmosphere of a planet like Jupiter. Still other 'brains' could actually be a swarm of 'social insects' acting like a single intelligence.

The great astronomer Fred Hoyle wrote a classic science fiction novel called The Black Cloud, in which a cloud of gas in the cosmos was permeated by swirling electric currents which made it a vast superintelligent brain.

If evolution on another planet in any way resembled the 'artificial intelligence' scenarios conjectured for the 21st century here on Earth, then the most likely and durable form of 'life' may be machines whose creators were long ago usurped or became extinct.

But even if the radio telescope at Arecibo has given us a false alarm this time and all future searches fail, that need not mean that we are alone.

The thought processes of aliens may be so different from ours that we couldn't recognise any patterns in their signals anyway. Or they may not be transmitting at all.

Superintelligent dolphins could be enjoying a contemplative life on some water-covered planet without us ever knowing of their existence.

Indeed, there may be a lot more life out there than we could ever detect - absence of evidence wouldn't be evidence of absence.

And if aliens do exist, we should perhaps be thankful to be left alone. An alien invasion might have a devastating effect on humanity, just as Europeans did on the North American Indians. The film, Independence Day, may be a truer depiction than 'ET' of what such an invasion would portend.

The fact that we don't seem to have had alien visitors so far should not make us so sceptical about the Arecibo results. It would be far harder to traverse the mind-boggling distances of interstellar space than to transmit a message.

The most systematic searches for alien life are led by the SETI (Search for Extra-Terrestrial Intelligence) Institute in California.

Their SETI@home project allows anyone who wishes to download and analyse part of the Arecibo data stream on their computer.

Millions have taken up this offer, each inspired by the hope of being first to find 'ET', and it was the luckiest of these amateurs who noticed the strange signal reported yesterday.

It makes sense for us earthlings to listen, rather than transmit.

Any two-way exchange would take decades at least, so there would be time to plan a measured response. In the long run, a dialogue could develop, but not snappy repartee.

BACK in the Sixties a German professor, Hans Freudenthal, devised an entire language - 'Lincos' - for interstellar communication. He showed how one could start with simple statements that aliens would surely understand, like one plus one equals two, and gradually build up a vocabulary, and diversify the discourse.

Any aliens would at least share the same universe as us, having some theme for conversation. They would, like us, be made of atoms; they would (if they had eyes) gaze out on the same cosmic vista. But beyond that, the culture gap may be unbridgeable - immeasurably greater than the separation in space and time between any recorded cultures on Earth.

For example, the Arecibo signal is thought to have travelled almost 183 trillion miles across space.

I, for one, would be massively disappointed if all our searches for alien life were doomed to fail.

We would then feel truly alone in a vast, uncaring cosmos.

On the other hand, there could be compensations. If our Earth were the unique abode of intelligence, rather than just one more planet in a Galaxy teeming with life, then it would be a huge boost to our cosmic self-esteem.

Our Final Century by Martin Rees is out now as an Arrow paperback, priced Pounds 7.99.

More News in this Category