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There is hope

Or fear, according to taste. Via Slashdot, I see that we now have a more sophisticated estimate of the number of alien civilizations out there.

From the abstract:

The search for extraterrestrial intelligence (SETI) has been heavily influenced by solutions to the Drake Equation, which . . . [relies] on using average values of key parameters . . . . A more accurate answer must take into account the distribution of stellar, planetary and biological attributes in the galaxy, as well as the stochastic nature of evolution itself. This paper outlines a method of Monte Carlo realisation which does this, and hence allows an estimation of the distribution of key parameters in SETI, as well as allowing a quantification of their errors (and the level of ignorance therein). Furthermore, it provides a means for competing theories of life and intelligence to be compared quantitatively.

Monte Carlo simulations run hundreds or thousands of times for each set of assumptions or parameters you’d like to test. This provides a distribution of answers for each set. It’s a technique that was known before computers, but not widely applied for obvious reasons. The really interesting thing about it is how well it predicts real world results in situations where we eventually find out the answers. This is not your granddad’s statistics.

Will it work well in estimating ETs? Maybe one day we’ll find out. But the estimate is fascinating. The lowest number of likely civilizations in our galaxy, i.e. using the most stringent assumptions, is 361. The highest is nearly 38,000. That’s only in our galaxy. For a sense of how many galaxies there are, look at deep space:

There are almost no stars in that picture.

Now all we have to do is discover faster than light travel . . . .

Technorati Tags: extraterrestrials, SETI, Drake equation, Duncan Forgan