[druskacik]

I always wondered about the idea posed in this short story. Does the "everything that can happen does happen" theory apply to free will? If there really are infinite universes, is there a one when I'm walking a street full of people and out of nowhere we all start singing Ode to Joy in perfect unisono? Or get naked and have a massive orgy? No law of physics rules this out.

(Sorry, I'm a layman.)

[rmi_]

I've always wondered if this (kinda widespread?) theory stems from most people thinking that "infitnity" includes every possible option, which is not true.

(I'm a layman, too)

[dzdt]

Mathematician here, so educated layman on the physics but expert on infinity if you like.

Mathematically, "infinity" doesn't imply every possible option. But in terms of quantum physics, yes it kind of does include every possible option. There is a kind of joke classroom exercise in quantum physics class to calculate the probability that a piano would instantaneously rematerialize a meter away from its previously observed location. Its 10^-[ ridiculous number] but still thats not zero.

The size of physical reconfiguration of a person's brain to cause them to break out singing is a much smaller deviation so comparatively likely. So 10^-[somewhat less ridiculous nunber]

[mhl47]

This is related to the question whether a system/the universe is ergodic (among other properties changing energy, space).

[druskacik]

Doesn't infinity include every possible option (possible meaning that it can happen within rules of physics)? If the model of the universe is one where events are happening with some probability, then if the probability is nonzero and the number of universes is infinite, then the event should happen in some of the universes.

(Still a layman, though.)