A repeated accusation on the true origin list is that I incorrectly consider everything with a probability smaller than 10^-150 (but greater than zero) to be impossible. Well, I do, but is it incorrect?
The analogy I want to make here is between "any event with a probability smaller than 10^-150 is impossible (in this universe)" and "any cube with a length smaller than 10^-40 cm is impossible (in this universe)". Why the second claim? Because the Planck limit, 10^-33 cm, dictates how small objects can be - nothing can be smaller than this, in our universe. The universe is discrete at this scale - you can find to points between which there is no other.
So, saying "a cube with a length smaller than 10^-40 cm (or anything smaller than 10^-33 cm) is impossible" is not wrong; it is actually correct. By analogy, saying that "anything with a probability less than 10^-150 is impossible" is not wrong - it really is impossible in our universe.