'The most fascinating phenomenon one could find in the universe would not be another kind of star or galaxy, but another kind of life'

- Frank Drake

This book is probably only widely available because it is co-authored by Dava Sobel, of 'Longitude' fame. It's a pity that it should take that to make 'Is Anyone Out There' readily accessible, because it deals with what I see as one of the most significant tasks facing humanity - to search for radio communications from extraterrestrial civilizations. This is not X-Files stuff (much as I like that fanciful series): it is one of the most important branches of science, and this fact is ill-appreciated. The priorities of space programs are shockingly awry; Drake writes with nice irony that in the 1960s,

'talk at NASA centered on an altogether different project [from SETI]: The United States would send a man to the Moon by the end of the decade. The populated worlds of other galaxies would have to wait in line far behind that priority'.

Putting humans on our nearest satellite; an interesting undertaking, to be sure, but one which pales into insignificance when compared with what we could be missing out on.

'Is Anyone Out There' is a history of the SETI (Search for ExtraTerrestrial Intelligence) enterprise by the man who is perhaps best-placed to give such an account. Frank Drake is pretty much the father of SETI; it was he who performed the first search, in 1960. He traces the roots of SETI, and gives an insider's account of the course of SETI since the 1960 search, named Ozma. As you can imagine, SETI has often been portrayed as a harebrained scheme, on a par with standing on hills waiting for UFOs (or, for that matter, the Apocalypse) to descend. Once you learn a little about it, however, it is plain that SETI has a very sound scientific footing. That is not to say that we know that aliens exist; clearly, we do not. And in spite of Drake's near-faith in the existence of ETs, it is simply impossible to deduce their existence from a priori arguments. As Drake correctly observes, SETI is in essence an experimental science, not a theoretical one. Only by observation can we confirm whether we are alone; and the way to do this is to listen out for signals which have crossed the unthinkably vast gulfs of interstellar space. Incidentally, the power of the equipment we have for undertaking the search is remarkable; Drake observes that 'all the energy collected in the history of radio astronomy barely equals the energy released when a few snowflakes fall on the ground'.

I am not won over by Drake's argument that we can expect aliens to stay within their own solar systems; he uses this argument to explain why we do not appear to have been visited by them. He reasons that the energy costs of interstellar travel are so immense that the aliens would much rather stay 'at home'; why waste energy which could be better spent without undertaking a long and tedious journey to the nearest star? Drake is of course right that interstellar travel would require enormous amounts of energy; light itself takes four years to reach our nearest stellar neighbour, and that is at a speed of 300,000 kilometres a second. Unless there are short-cuts (i.e. laws of physics) which we haven't yet thought of (or understood how to exploit), any interstellar travel is likely to be far slower than the speed of light. "If the energy used to put one colonist on a new planet is far greater than the energy required to give that colonist a good life back on the home planet, they won't bother". The flaw in Drake's argument is that once all the necessary energy has been expended, the losses can be recouped a million billion-fold by harnessing the energies of the star which has just been reached. Drake also writes 'Try to picture yourself sitting in a DC-9 for forty thousand years, eating airline food and watching the same movies over and over again'. The idea that high speeds are necessary to stave off the boredom of transit is also short-sighted; the idea of putting beings (organic or machine) in stasis is an old one, and is clearly workable under some circumstances. In the unlikely event that stasis could never be achieved, then surely we might expect the aliens to have rather excellent machine-based ways of diverting themselves - their equivalents of videos and computer games might give Nintendo and Hollywood a bit of a run for their money. I am not saying that aliens (if they exist) do migrate to other stars; we just don't know.

On most SETI issues, though, Drake is way ahead of me. If SETI strikes you as a worthwhile enterprise, reading this book is an excellent way of finding out about it.

To buy the paperback edition of 'Is Anyone Out There' (£4.79 - about $7.00), click here.
To buy the clothback edition (£14.85 - about $22.00), click here.