Because our galaxy is teeming with planets it should be home to countless extraterrestrial civilizations. That is unless, through some perverse twist in nature, intelligent life is an evolutionary dead-end.
But let's be optimistic and assume that some fraction of far-flung worlds rise to the status of a hosting a super-civilization.
This was described in 1964 by Russian astronomer Nikolai Kardashev who hypothesized that a so-called Type III civilization would control the entire energy output of a galaxy. (We don't even reach Type I status because we have failed to harness nuclear fusion or build a constellation of solar power satellites.)
But why should a super-civilization be so energy voracious? And how in the heavens do they tap the energy of an entire galaxy?
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