This month’s feature article in PhysicsWorld is a plea by well-known science (particularly physics) writer Paul Davies to relaunch (or rather, expand) the search for extra-terrestrial life. The Search For Extraterrestrial Intelligence (SETI) has been around for nearly fifty years, focusing on analyzing data from radio telescopes. But Paul Davies thinks there are other places where we could and should look for signs of alien activity, not least our own backyard.
The article mentions the neat argument by Enrico Fermi as to why space-faring life elsewhere in the Milky Way is unlikely. The galaxy’s age is currently thought to be about 13 billion years, give or take (essentially, the age of the universe), whereas its diameter is only a piddly little 100 000 light years. Fermi’s argument is basically that if life capable of intergalactic travel has evolved elsewhere there is bags of time for it to have travelled across and colonized the whole galaxy by now. Since we don’t see any evidence of it, the conclusion is that it isn’t there.
There are counters to Fermi’s argument – for example, an alien civilization may have arrived in the past and left again. In which case, do traces of its existence still remain on earth?
I’ll leave you to read the article, but I will argue now that I would be firmly against such a project. I’ll give two reasons:
1. It is a waste of our time and resources. Humanity has enough problems to contend to at the moment, such as feeding itself while not inducing major destructive climate change. (I will add, of course, that I do not like to dismiss ‘blue-sky’ research out-of-hand – it is from this kind of research that often new technologies are developed that will benefit in ways that are unforeseen – but in my opinion there is plenty of other ‘blue-sky’ stuff (e.g. the Large Hadron Collider) which is well ahead of this in likely benefit to humanity.)
2. What would we do if we discovered that there was space-faring extra-terrestrial life somewhere out there? It seems to me inappropriate to look for it if we do not know how we would respond if we found it. Is the best thing to do to keep quiet? Or to signal it? (Though I feel this question would be irrelevant – whatever governments and the UN might advise, someone, somewhere, would send out a signal to it – that is pretty inevitable.) The world does not have a great track record on agreeing on anything, and this, surely, would be a question that would need a unified, world response.