Scientists and engineers love equations. Not only do they make the modern world possible, they can be a lot of fun at parties. At least the kind scientists and engineers throw. And we (I’m just a country engineer) all love a good back of the envelope calculation, which is how one turns a WAG (Wild Assed Guess) into a SWAG (Scientific Wild Assed Guess). So I have to applaud Prof Andrew Watson for this Cosmic SWAG of a calculation:

Is there anybody out there? Probably not, according to a scientist from the University of East Anglia. A mathematical model produced by Prof Andrew Watson suggests that the odds of finding new life on other Earth-like planets are low, given the time it has taken for beings such as humans to evolve and the remaining life span of Earth.Structurally complex and intelligent life evolved late on Earth and it has already been suggested that this process might be governed by a small number of very difficult evolutionary steps.

Prof Watson, from the School of Environmental Sciences, takes this idea further by looking at the probability of each of these critical steps occurring in relation to the life span of Earth, giving an improved mathematical model for the evolution of intelligent life.

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His model, published in the journal Astrobiology, suggests an upper limit for the probability of each step occurring is 10 per cent or less, so the chances of intelligent life emerging is low – less than 0.01 per cent over four billion years.

I bet that makes him a big hit at all the parties, especially with thePanspermia-ists, who were a pretty lively bunch to begin with.