How Can an Infinite Universe Expand?

[LSulayman]

I'm reading a lot of stuff about the expanding universe, and also about it being infinte.
So now I was wondering:
How can the universe expand while it's infinte? (or am I asking something that nobody really know's the answer to?)

 

[marcus]

...
How can the universe expand while it's infinite?

You have to understand what the cosmologists who say "expand" mean by that word.

They mean that distances between widely separated galaxies are increasing.

On average the rate of increase is currently about 1/140 of one percent every million years.


They do not mean that you could stand outside the universe and see it get bigger!

They are talking about a pattern of distance-growth seen from inside.

...
How can the universe expand while it's infinite?

An infinite thing can have that pattern of distance-growth, just as easily as a finite thing.

It is expansion seen from the inside. So the thing does not have to be finite.

 

[LSulayman]

You have to understand what the cosmologists who say "expand" mean by that word.

They mean that distances between widely separated galaxies are increasing.

On average the rate of increase is currently about 1/140 of one percent every million years.


They do not mean that you could stand outside the universe and see it get bigger!

They are talking about a pattern of distance-growth seen from inside.



An infinite thing can have that pattern of distance-growth, just as easily as a finite thing.

It is expansion seen from the inside. So the thing does not have to be finite.

Thank you! I actually didn't know that, nobody really explains it in all the articles I read.