How does an atom of a radioactive substance know when it is to decay?
Imagine a single atom of a radioactive substance. It will decay at some point in time but how does it choose when? Imagine two such atoms. They are identical so why should one decay right now and the other in one million years time. And how does it come about that given a large enough quantity of such atoms there is a precise time in the future when exactly half of them will have decayed? Where does this precision come from?
This question is in the General Section. Responses must be helpful and on-topic.