Simple math would tell you that out of the trillions of stars in the Local Group alone that there is a high probability that there is some life somewhere out there.
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We obviously live in a solar system that is friendly to life, yet life is very rare within it. Even here on Earth the ratio of biomass to mass is about 3 parts in 10 billion. I’d say your math isn’t so simple.
It's always easier to say the math is simple ... than to provide that supposedly simple math.
” I’d say your math isn’t so simple.”
But the point is that the math is there.