Problems with S.E.T.I.

One of the problems with locating an extra-terrestrial intelligence is that the gap between the discovery of radio and much more advanced technology is so small. By the year 2000, only about 100 years after the discovery of radio, complex digital signals were already replacing simple and easy to detect waveforms. Given that it took 4.5 billion years from the formation of the Earth to the discovery of radio, and that it was broadcasting simple waveforms for only 100 years then the odds of discovering any technologically similar broadcaster would be very small, even if Earth-like planets and life were commonplace. By the year 2000, simple signals were still being broadcast however, and it is always possible that a complex civilisation could decipher complex digital radio signals from a distant planet.

A second problem is that the discovery of radio pre-empted the invention of atomic weapons by only a few decades. The ability to destroy our civilisation was discovered almost as soon as we had the ability to broadcast to another planet. Atomic weapons are controlled by people, and people can make mistakes and react unpredictably in tense situations. When a weapon that can destroy all life exists, it will inevitably be used because in any situation involving judgement, misjudgements can happen. The distance in time between the discovery or radio and destruction of a civilisation by atomic weapons would certainly be smaller than the distance between the formation of a planet and the formation of intelligent life. This further reduces the odds of discovery on an extra-terrestrial intelligence.

Mark Sheeky, 29 Dec 2006