Life off Earth - Do Aliens Exist?

But the call has never come despite some heart-stopping moments when interference looked like the real thing. Some astronomers now are considering the possibility that advanced civilisations might instead use laser beams to make contact, and are searching the sky for suspicious flashes of light. But how do you second-guess ET?

Friend or foe?

And some scientists reckon that astronomers should not be conducting SETI at all. Contact with aliens, they believe, would be downright dangerous for us. Anthropologists have fears that an advanced intelligence if it had mastered interstellar travel could come to Earth and wipe out the human race, on the grounds that living creatures are programmed to wipe out rivals. Other researchers believe that the results of downloading the total sum of knowledge from an alien intelligence would blow our puny brains.

But I strongly believe that a dialogue with a more advanced intelligence would help us. We'd learn from their mistakes and benefit from their advanced knowledge. Of course, none of this would stop us being human, although I think it would change us in ways we cannot yet know.

For those who urge astronomers to call off the search in case we do make contact, I can only say one thing: it's too late. For the past 70 years, the powerful signals generated by radio and TV transmitters have been leaking away from our planet at the speed of light. They have already reached hundreds of the nearest stars. If "they" are out there, they already know that we are here.

For more information

DVD: Close Encounters [Firstscience presents]
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DVD: Alien Contact [Firstscience presents]
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