SETI scientists are having a rethink about what they should be looking for. Previously the radio receivers have been tuned to the "waterhole" at around 1 GHz where the hydrogen atoms and OH groups emit their characteristic "noise".
Since alien biological life is likely to depend on H2O it will recognise this part of the spectrum as very significant. Conveniently the 1-10 GHz range is also naturally quiet which makes it a good place to attempt a conversation. So the theory has it that that is where aliens are broadcasting.
But there's new thinking. It goes like this. It takes life about 3 billion years to evolve from nothing to making a radio transmitter. Two or three hundred years later it will turn into non-biological artificial intelligence and that's how it will remain for the millions or billions of years of its subsequent existence. So the "waterhole" is of no significance and SETI should be looking elsewhere.
This blog reckons SETI scientists haven't quite got the whole picture yet.
Let us imagine that the giant meteorite which killed the dinosaurs arrived a fraction early, say 66 million years ago rather then 65 million years ago. Then the rise of the mammals would have occurred a million years earlier and today's date would be 23rd August 1002010 AD rather than 23-Aug-2010. Where would the human race already be if that meteor had been created with a tiny fraction more momentum or a sliver of a tighter orbit?
With a million years' head start we'd either be extinct or all over the galaxy, possibly both.
There must be intelligent creatures out there, biological or machine, which have that kind of lead over us. There must be civilisations out there with a billion years' head start! By now they must have discovered planet Earth. And it's not likely they would have discovered us, said "boring", and moved on. No, once discovered we'd stay discovered.
So where are they then? Well, either choosing not to show themselves, or all around and we're just not recognising them for what they are. Either way, straining at the stars is looking in the wrong place. Look closer to home. Does your neighbour have slightly pointed ears?