Answer to Question #218157 in Physics for Terrun

Question

Although I have read a lot about the multiverse hypothesis, I have yet to read anything with real life scientific ideas on how one would get to another universe. Does anybody know of anything I could read on this subject?

Answer 1

The universe began as a Big Bang and almost immediately began to expand faster than the speed of light in a growth spurt called “inflation.” This sudden stretching smoothed out the cosmos, smearing matter and radiation equally across it like ketchup and mustard on a hamburger bun.

That expansion stopped after just a fraction of a second. But according to an idea called the “inflationary multiverse,” it continues—just not in our universe where we could see it. And as it does, it spawns other universes. And even when it stops in those spaces, it continues in still others. This “eternal inflation” would have created an infinite number of other universes.

Together, these cosmic islands form what scientists call a “multiverse.” On each of these islands, the physical fundamentals of that universe—like the charges and masses of electrons and protons and the way space expands—could be different.

Cosmologists mostly study this inflationary version of the multiverse, but the strange scenario can takes other forms, as well. Imagine, for example, that the cosmos is infinite. Then the part of it that we can see—the visible universe—is just one of an uncountable number of other, same-sized universes that add together to make a multiverse. Another version, called the “Many Worlds Interpretation,” comes from quantum mechanics. Here, every time a physical particle, such as an electron, has multiple options, it takes all of them—each in a different, newly spawned universe.