The Search for Extra-Terrestrial Intelligence, 1997

For thousands of years Mercury, Venus, Mars, Jupiter and Saturn have been recognised as planets because they move independently of the stars, and yet the next planet, Uranus, was not discovered until 1781. It had been seen many times before and assumed to be a star. It could even be seen by a person with good eyesight without the aid of a telescope. It seems incredible that nobody bothered to check its position from time to time to see if it was a planet.

It may be that a person looking back on the present time from hundreds of years in the future will find it equally incredible that the people of the 1990s didn’t put more effort into the Search for Extra-Terrestrial Intelligence than they did.

It is known that there are about 1021 stars in the Universe. Recent evidence that several stars in our neighbourhood have planets suggests that the number of planets is of the same order. The even more recent discovery of a primitive fossil in a Martian meteorite suggests that the number of planets on which some form of life has existed is not very much smaller. What is more difficult to assess is how likely it is that primitive organisms like the one found on Mars will evolve into a civilisation advanced enough to communicate by radio, but surely the odds against this happening cannot be so long that it has only happened once on all those millions of millions of planets.

We must remember that the Universe is so old that many civilisations may have been in contact with each other for hundreds of millions of years. We will be merely eavesdropping on their conversations; it is unlikely that there will be time for us to reply within the lifetime of anyone living today. There will be no difficulty in decifering pictures, and these will tell us a great deal about life on distant planets, but interpreting actual text or commentary will be like trying to read hieroglyphics without the Rosetta stone.

However, if we ever do decifer these messages the benefits could be enormous. We might be able to learn about our own future by reading what happened to other civilisations after they reached our level of development. It might become un­necessary for large amounts of time and money to be devoted to scientific research because all this can be done by studying research carried out long ago in distant parts of the Universe.

It is impossible to say how many solar systems will have to be investigated in order to make success likely. All that can be said is that if a million systems are investigated success is a thousand times as likely as if only a thousand systems are investigated. So long as the technology is available the likelihood of success will depend entirely on the number of people involved and the amount of time they devote to the project.

The governments of the major countries should be devoting a large part of their resources to the Search for Extra-Terrestrial Intelligence, but the search is now in the hands of a group of amateurs  Anyone who believes that the project should be deprived of the necessary resources because it is unlikely to succeed would do well to assess the relevance of  the following statements that have been made in the past:

‘Flight by machines heavier than air is unpractical and insignificant, if not utterly impossible.’ Simon Newcomb, 1902.

‘The horseless carriage is a luxury for the wealthy;  it will never come into as common use as the bicycle.’ Literary Digest, 1889.

‘Speaking movies are impossible. When a century has passed, all thought of our so-called speaking movies will have to be abandoned. It will never be possible to synchronise the voice with the picture.’ D.W. Griffith, early 1920s.


[Note:  On September 17th, 1999 I heared on the radio that there are now a million people taking part in the Search for Extra-Terrestrial Intelligence.]