Hi, I'm sorry if this is the wrong section. My Dad keeps telling me that light takes the path of most time elapsed between two points, and he remembers hearing this because it's counter intuitive. I'm a Physics undergrad myself but I can't see if and how there's any truth behind this. I've searched and found nothing even equivalent to this fact. So if it were to be true I can only imagine it's from post-graduate/research level work or from a module I haven't taken. The only thing I can guess is that light is a quantum mechanical particle and hence takes every path from A to B, but the probability of taking anything but path of shortest time elapsed is so low that it practically never takes it? Again, the statement wouldn't make sense to everything I already know, but that doesn't exclude the fact there may be some technicality where we can observe light taking the path of most time elapsed? Any links to sources would be appreciated.