What is the Universe expanding into?

What is the Universe expanding into?

...

Nothing

...

itself

God

A penis

It's not expanding 'into' anything at all. The internal relata of its (space itself) parts are increasing.

Or I shouldn't say that I guess, quite, it's increasing in quantity more importantly.

Also, there is the subspace 'hypothesis' too, if you're into that sort of thing.

would saying it is expanding in the 4th dimension be a good way to describe it

based on the inflating balloon example which "stretches" in the 2nd dimension and expands into the 3rd, it might be "stretching" in the 3rd dimension and expanding in the 4th

Nothing, space itself is part of the universe.

No, that would be confusing since "4th dimension" is usually taken to mean time. It's expanding orthogonally to itself, this isn't something we have direct experience of so we can't visualise it.

Consider a 2d surface such as a sheet of paper, and then consider the 2d creatures that might occupy such a place. Try explaining to one of them what you mean by "three dimensional", and try to answer their question of "but where does the third dimension expand into?".

the question dosent make sense. space and time are expanding, its not expanding into anything. i guess you could word it to say the fabric of the universe is stretching itself out, but im not too sure if that paints the right picture

Not OP but it makes perfectly good sense, it's just an example of where our human-scale intuitions break down at the scale of universes. The question refers to real things (space) and is grammatically and logically coherent, it's reality itself that "doesn't make sense" in this case.

most scientific minds just assume that the universe expands indefinitely, as to what effect that takes on all matter as a whole is unknown.

but not like all of that matters to us, the sun is going to go red giant and swallow the planet sooner than universal expansion has a noticeable effect on humanity.

goatse

It's not. Spacetime in it is expanding until it reaches the walls of it (think of the Universe as a sort of egg with a well defined surface limit). Outside of it there are other universes, like other eggs, some bigger some smaller and some with really fucked physics. The only parameter equal to all is gravity. In fact our egg is being sucked out by a bigger egg.

All of the eggs are virtual ofc. Nothing more than a tiny amount of pixels in an alien simulation.

>No, that would be confusing since "4th dimension" is usually taken to mean time

All dimensions involve both space and time, they're connected

damn, fuckin aliens

Simulation to do what though?

Whatever bullshit he makes up next.

Itself. Think of it more like subdividing the same volume rather than increasing in size

raisin muffin in the oven

They're connected certainly but they're not the same. We have three dimensions of space and one of time, assuming String Theory isn't correct in which case we have 10 more space dimensions but they're all compressed into infinitesimal "strings".