[𝔦 • ──⃝─⃝⃝⃝⃝──] 많은 세계 a lot of worlds.

“every choice we make may have spawned a whole new universe with a whole new history, and a whole new version of ourselves”

quantum mechanics, as a scientific theory, carries with it uncertainty.

every measurement has a margin of error at the subatomic level, and every event has the possibility of occurring or not.

in our universe, however, only one outcome occurs out of all the possible ones; the final outcome, which can be observed and measured, will forever influence everything that happens next.

a mathematically valid way to deal with that uncertainty is to say that all possible outcomes actually occur, but that their different effects also occur in the future. thus, for every event in the history of time, a completely new timeline is created.

each timeline is as valid as any other, so instead of one world experiencing a single past, present, and future, there are many parallel worlds—it's the “many worlds interpretation” (MWI)—none of which can communicate with any of the others.

the one we're concerned with, of course, is the one in which we share our existences and experiences.

we may exist right now in a parallel universe and be looking at these very words, but we may be wearing different clothes, or having a different haircut, or living in a yellow submarine.

who knows when we'll know for sure.

there’s an interpretation of quantum mechanics that implies the existence of a vast number of parallel universes that are created every microsecond of cosmic history.

if the quantum mechanical MWI is correct, the number of timelines that have been created since the big bang is staggering, and even more are being produced all the time. Everything that could have happened in the history of our universe but didn't actually happen did happen, but in another universe.

the total number of timelines, however, doesn't have to be infinite, and some things that could never have happened in our universe may not have happened anywhere else either.