Astrophysicists apply new logic to downplay the probability of extraterrestrial life

David Spiegel of Princeton University and Edwin Turner from the University of Tokyo have published a paper on arXiv that turns the Drake equation on its head. Instead of assuming that life would naturally evolve if conditions were similar to that found here on Earth, the two use Bayesian reasoning to show that just because we evolved in such conditions, doesn’t mean that the same occurrence would necessarily happen elsewhere; using evidence of our own existence doesn’t show anything they argue, other than that we are here.