You wrote: This is also mathematically true: given a coin with only the most minimal bias, cumulative results of coin tosses will eventually drift far away from

You wrote: This is also mathematically true: given a coin with only the most minimal bias, cumulative results of coin tosses will eventually drift far away from 50% This is what troubles me. I understand your point. But, if it takes a trillion years to 'drift away from 50/50' is it meaningful to describe the bias as something other than zero? That is, is there some Plank's Constant kinda-thing for probabilities? The reason this always comes to mind is the absurdly low probabilistic effect on fecundity of, say, a finch having a 4cm beak versus a 4.1cm beak. If the effect is some probability so low that it would take millions of generations to manifest itself, then, in light of the fact that finches were probably single-celled organisms a million generations back, the probability may as well be zero.