Quote:
Originally Posted by Atmos
If you believe that life is enivitable given enough time then the universe will be teeming with life. If you don’t believe that, then we’re alone.
Pick a number, any number  |
The biggest range of assumed values in the Drake equation tend to relate to fl (the fraction of planets that could support life that actually develop life at some point). At present, we know of only one planet where life has developed out of thousands of known worlds, and the pessimists are inclined to think that fl approaches zero.
If we actually discover evidence for some form of life (current or past) elsewhere in our Solar System (Mars, Europa, Enceladus, etc), or elsewhere in the universe (e.g. bio-signatures in the atmosphere of an exo-planet), then that will tend to push estimates for fl to something much closer to 1 (don't forget - even 1 in 1,000 is MUCH bigger than some of the pessimistic estimates), and the inevitable conclusion would be that life is teeming throughout the universe.
As for intelligent, communicating life - well, again, in the absence of any signals, the pessimists are inclined to think that the probability of technologically advanced life is approximately zero. However, we would need just one signal from "out there" to promote estimates for fi (the fraction of planets with life that actually go on to develop intelligent life) and fc (the fraction of civilizations that develop a technology that releases detectable signs of their existence into space) to values much higher than the pessimistic estimates, and just one such signal would lead to the inevitable conclusion that the universe is teeming with technologically advanced lifeforms.