Is this the only universe?

That seems like kind of an important question, doesn't it?

Like, we live in a universe, it exists, it is all of existence, but is that it? It's fun to imagine other universes,

isn't it? With another you, another life, you know, think of all the choices you've made

all over the years, big and small, like who to marry, where to live, what to have for dinner, what to put on your salad.

Imagine a whole other universe where the only thing is different is that you got the Italian

dressing instead of the ranch and it totally changed your life.

Like what if you turned left instead of right last Tuesday at that intersection?

How would your life be different?

What if you moved to Buffalo or moved away

from Buffalo for that job? You run that movie forward and imagine you're running in parallel, right? Like,

a slightly different version of you just vaguely over there somewhere else in another universe, a parallel universe, a perpendicular universe,

an alternate universe. And if these different universes are possible, these different options

that represent all sorts of different choices, could you like hop between them, could you

jump, could you mix them, so to speak? Could you

grab one universe and bring it over? These are important questions, right? But I suppose first we

need to define universe. Right? The usual definition, if I say universe, you probably think all the things,

all there is, which if we take the word universe to mean all the things, it means there's no

such thing as multiverse, which is the subject of this episode, because there's only one universe,

which is all the things,

which includes all the possible options. That's not quite a useful definition, and that's why

the word multiverse comes in, because when a cosmologist, like me, or an astronomeromer uses the word universe, they usually mean something

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