Armchair Scientist

Alien Searches at Home

I have become a radio astronomer, but strictly of the armchair sort. I don't have to attend staff meetings or complain about leaky microwave ovens, or climb up ladders to look after the antennae during a gale. I merely get through a huge amount of work by occasionally clicking a mouse. I have joined the now three million-strong SETI-at-home search for alien civilisations. It is worth doing this, if only for the sheer wonder of it. For about 16 hours at a stretch (slower computers than mine take up to 55 hours), my computer processes a block of raw radio data half the length of a novel. The appearance of this

on the screen is extraordinary. It looks as if someone or something is searching at great speed and thoroughness though miles of filing cabinets. What is really happening, of course, is that the computer is performing an FFT, a fast Fourier transform. I seek guidance about this from the SETI home page and am told: "This is a complex mathematical operation that turns a set of time-based data into a set of frequency-based data. For more information on the FFT, please consult a book on digital signal processing". But what is really remarkable is until a few years ago all this work was performed by NASA supercomputers. In those days our chief worry was that Congress might cancel the project - which it eventually did, and it was privatised. From the pronouncements of politicians it was clear that this might happen. Former Senator William Proxmire called SETI "crazy science fiction which should be postponed for a few million light years", a statement that led the late Isaac Asimov to deduce that Proxmire was "bone from ear to ear". And I have this gem from an unnamed Congressman: "Of course there are flying saucers and advanced civilisations in outer space. But we don't need to spend millions to find evidence of these rascally creatures. We need only 75 cents to buy a tabloid at the local supermarket. Conclusive evidence of these crafty critters can be found at checkout counters from coast to coast." And a few years ago the UK Cutty Sark Scotch Whisky Company offered a prize of £1 million to anyone who could find an alien spacecraft and bring it at their own expense to the London Science Museum to be verified by unnamed `experts'. The main problem was how the winner should bring a vehicle that presumably would weigh tens of thousands of tons into Central London without knocking down buildings, and whether this would cost more than the prize money. But at last the SETI project is free from the whims of idiots and on ordinary peoples' hard disks. And the person whose computer finds an alien signal will be publicly named. So I have a one in 1.3 million chance of being listed in an encyclopedia of famous scientists.