Sean Carroll

Here's the vial of gas.

Here's the Geiger counter.

Here's the source, et cetera.

Here's the observer.

So you want to basically divide Hilbert space into subsystems that connect to or represent things that you'd identify as objects in the real world, okay?

Again, that's not there in the description of the theory in this bare-bones Everettian sense.

It's something we're inventing.

So there might be a good way to do that or a bad way to do it.

The other way that space shows up, which is, again, it's connected, but it's a little bit different in presentation.

In quantum field theory, which we think is the best way that we have of successfully describing particle physics and things like that,

Things are made of fields, right?

So the electron is a vibration in the electron field.

That's why all two electrons are the same.

There's that famous idea by Wheeler that all electrons are the same because they're really the same electron.

That is wrong.

It doesn't work.

The real answer is why are all electrons the same?

Because they're all vibrations in a single underlying electron field.

All photons are vibrations in a single underlying electromagnetic field, etc.,

Fields are defined as objects that take on a value at every point in space, or every point in space time, if you want to put it that way.