4 ms·
He estimates f_l, the probability of life arising in a habitable planet, as 0.1. Abiogenesis has never been observed to occur independently of its presumed occ
by pjdorrell 10y ago
He estimates f_l, the probability of life arising in a habitable planet, as 0.1.
Abiogenesis has never been observed to occur independently of its presumed occurrence when life started on Earth.
Given the current state of scientific knowledge on this topic, the only certain lower bound on this number is the probability of molecules in a suitable "organic soup" arranging themselves into a self-contained bacterium. And that probability is a _very_ small number.
If f_l is _very_ small, then there is no need to be pessimistic about our own long-term survival. We see no advanced alien civilisations, because there is no other life out there of any kind - the rest of the observable universe is sterile.
- gerbal 10y agoEven if abiogenesis is common, the transition from simple to complex cells is incredibly uncommon. As far as we can tell it only happened on earth once in 4 billion years. f_l may be 0.1 but f_i is almost certainly multiple orders of magnitude smaller.