SETI's 'L Factor': Will E.T. Actually Be Around Long Enough To Phone Home?

“2001:  A Space Odyssey” is barely into its first reel when the film’s signature alien monolith shows up on some ancient East African savanna.But when making “first contact” with this highly-advanced alien artifact, the film’s much-evolved astronauts appear as flummoxed as their hominid predecessors.

From the get-go, the implications are obvious:The road from ape to astronaut has been long and tortuous. And once we’ve truly moved off-world, we can expect non-human company.But is it necessarily so?

Will extraterrestrial civilizations (E.T.) actually persist long enough to make contact with each other?

Fifty years after astronomer Frank Drake came up with his famous equation to place parameters on the number of detectable extraterrestrial civilizations within our galaxy, the “L” factor is arguably the most disputed.  Yet it’s the one factor that quantifies “the length of time such civilizations release detectable signals into space.”

“Of any factor in the Drake equation, L (the lifetime of [detectable] civilizations) is the most difficult to estimate,” said Douglas Vakoch, a clinical psychologist and Director of Interstellar Message Composition at the SETI (Search for Extraterrestrial Intelligence) Institute.  “If we’re interested in making contact, it’s not enough that a civilization simply exists.  It needs to be sending radio signals or laser pulses, or some other form of signal that we can detect.”

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