system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The universe is "Expanding"

I've heard people say that the universe is not as much expanding as it is growing; The distance between everything is increasing.

Right? So does this mean that there sort of is a limit to the size of the universe? we just can never get there? Imagine that I could move infinitely quickly through space, would I ever catch the expansion of the universe? Could I fall off the edge or does it loop around?

Fuck, I'm wrecking my head thinking about this, I enjoy being mind fucked though. Help me understand what it means for the universe to be expanding.

EDIT: oh, also, I'm not sure I understand he names of things, is there only 1 universe? and "Universe" is just the name for 'absolutely everything'? or are there lots of universes floating around? what's at the end?
gpt
Imagine you have a ruler that is shrinking... so today you use it to measure the distance from your house to that big tree in the back yard. 50 ft... wonderful... BUT TOMORROW... (since your ruler is shrinking) you measure it to be 55 ft... is your yard expanding? No, not really, all that is changing is the "ruler".

In physics this is called the "scale factor", it turns out that (based on all our observations and best current theories) that the "scale factor" is not constant, it changes with time, and in fact it is not just changing, but right now it is shrinking at an accelerated rate... that makes it seem to us that the Universe is expanding at an accelerated rate... but nothing is really expanding, only the measured distance *between points far apart is changing*. (far apart here means REALLY FAR APART, like the distance between two super clusters of galaxies, there is no expansion say between the Milky Way and Andromeda as we are part of the same neighborhood of galaxies)