And The Number of Intelligent Civilizations In Our Galaxy Is...

31573.52

No really. At least according to Duncan Forgan at the Institute for Astronomy at the University of Edinburgh.

The Drake equation famously calculates the number of advanced
civilisations that should populate our galaxy right now. The result is
hugely sensitive to the assumptions you make about factors such as the
number of planets that orbit a host star that are potentially
habitable, how many of these actually develop life and what fraction of
that goes onto become intelligent etc.

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