system
Given the following post, respond as if you're commenting on Reddit:
human
Is it possible that instead of the universe expanding, the matter inside it is shrinking?

As I understand it, the universe is getting larger because the space between things inside it is getting larger. Its not just that we are drifting away or flying apart, the actual 'space' is getting bigger (inflation).

Does it make sense that matter is shrinking inside a static universe, and that the 'heat death' is the point at which we can't get any smaller and everything just stops?
gpt
No not really. All of the forces that govern matter are distance dependent, so matter can't really shrink. Furthermore not *all* of space is evenly expanding. There are pockets of the universe where matter dominates and space doesn't expand, these being clusters of galaxies and the stuff within those clusters.