Sunday, January 08, 2017

The Search for Life: The Drake Equation (2010)

I don’t remember exactly when I learned of the Drake Equation.  It was first created by Frank Drake back in 1960 to give us an idea of how many communicating civilizations are out there in our galaxy.  We have a good idea of how many stars are out there, but back when it was first written down, much of it was guessing.  We’ve learned some things since then, but it’s still a lot of guessing.

The equation has seven different factors.  First, you take the rate at which stars form.  Then, multiply by the fraction of stars that have planets, and multiply again by the fraction of those planets that can support life.  You then multiply by the fraction of capable planets that do support life and by the fraction of life-bearing planets that develop intelligent life.  Finally, you multiply by the fraction of civilizations that develop the ability to communicate and by the length of time that the do communicate.  Drake’s original numbers gave us an estimate of 50,000 communicating civilizations.

This documentary is a very basic overview of the Drake Equation.  It starts with what the equation is and how it was used to start what eventually became SETI.  Drake wanted to use radio telescopes to find aliens, as that was the most promising avenue of exploration at the time.  (One thing I’ve always wondered is why we assume radio will be the means of communication if a civilization chooses to communicate at all.  I know it‘s really all we have, but I would think it’s not likely that they would necessarily develop or use radio to communicate.)

The Fermi Paradox is also brought up.  Enrico Fermi once asked where all the aliens were if there were supposed to be so many.  Well, life might not form that easily.  Sure, life formed quickly on our planet, but we don’t know if we just got lucky.  Even if life does form, there’s no promise of it becoming multicellular.  It does seem, however, that it is likely that multicellular life will develop intelligence.  Also, 50,000 civilizations isn’t that many when you consider that there are billions of stars in our galaxy, and there may not even be that many.  There may be something that keeps civilizations from getting that far.

It’s a pretty safe documentary.  It was produced by the BBC, which lends a fair amount of credibility.  At an hour, it’s the kind of thing that a teacher could play for a class if their normal plans got cancelled.  If the children are old enough to handle the basic concept of aliens, this should be appropriate for them.  There’s nothing about abduction or invasion or anything else that might be scary.  It seems to be meant as an introduction to the Drake Equation.  It probably won’t be of much interest to those that know more about the subject.

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