SHOULD we break our interstellar silence? In the 50 years we have been scanning the skies in search of extraterrestrial intelligence, all we have heard is a whole lot of nothing. We have even sent a few hopeful transmissions into space, to no avail. Now some SETI researchers are suggesting that we take a more active approach and systematically advertise our existence to the cosmos (see 鈥淲e鈥檙e from Earth. Hi there!鈥�).
Others say this would be rash, and that to shout into the dark is unwise when we have very little idea who, or what, is out there. There鈥檚 a good evolutionary argument that any intelligent alien species is likely to be predatory (see 鈥淢eet the cosmic neighbours鈥�). While it is far-fetched to worry that they will want to prey on us, they may, like us, have aggressive tendencies. Physical invasion is improbable, but electronic warfare could be waged across the light years in the form of computer viruses or even intelligent avatars.
Cosmic culture shock is a more likely consequence. When two human civilisations with very different levels of technology make contact, the less technologically developed one tends to come off badly. While that does not bode well for us, especially if ET鈥檚 civilisation has had millions of years to evolve, the optimists hope that sophisticated extraterrestrials will know how to cushion the culture shock while still showing us their marvels.
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These arguments and more will be debated next week in London at a . It will not be the first time the issues have been aired, and nobody expects a firm conclusion, but simply talking them through could encourage us to develop some vital humility. Contact is most unsettling for cultures who think they are the centre of the universe, so we would be well advised to prepare ourselves for the revelation that in galactic terms humanity is merely one small and backward tribe.
So should we try to promote contact by broadcasting our presence to the heavens? If alien civilisations exist, they are likely to be so far away that our message will not arrive until after we are gone. In that case, what is there to lose? We might as well let them know that we used to be around.
If, by chance, there are intelligent aliens within a few tens of light years from Earth, their own SETI programmes might already have sniffed us out, by picking up the spectral signs of industrial pollution in our atmosphere, or tuning in to our broadcasts. It is not inconceivable that our presence has already been noted by some nearby alien civilisation. So let鈥檚 make some friendly overtures, rather than leave them to wonder why we鈥檙e not transmitting, and what we鈥檝e got to hide.
鈥淚t is not inconceivable that our presence has already been noted by some nearby alien civilisation鈥�