I just read on the BBC’s site that there really are intelligent aliens. This article may represent the research accurately, but that just tells us that the ‘research’ is a bunch of people making up shit and feeding it into a computer and acting like the results mean anything. A few problems with assigning numbers to any of these things:

1. Almost all of the planets so far discovered around other stars are gas giants, though they are sure they have detected signs of a few rocky planets very recently. Applying Earth models for the appearance of life and evolution is meaningless in these totally different environments.

2. We don’t understand the origins of life anything like well enough to guess how typical our pace was – though complexity theory offers hugely promising models for this investigation.

3. We only have any comprehension of the pace of evolution on this planet. There is no reason whatsoever to think Earth is any sense typical or average of rocky planets – certainly the other three in this system are not at all similar.

4. We have almost no idea of how intelligence evolved, beyond the basic requirements for survival, as seen in many animals. This makes it pointless assigning figures to how likely it is to evolve.

As far as I can tell these people have taken guesses based on the tiniest sliver of evidence as to how common rocky planets are, and then said something that amounts to “if lots of them are like Earth, lots of them will be like Earth => hurrah, intelligent life abounds!”

By the way, if you don’t think the BBC article is dumb enough on its own, read the comments below it.