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> when we say the universe is expanding, we mean that matter is spreading out It's been a while, but I recall reading in a book that's actually the space betwe
by ecnahc515 7y ago
> when we say the universe is expanding, we mean that matter is spreading out
It's been a while, but I recall reading in a book that's actually the space between everything that's expanding, much like you state in your second paragraph. For example, if you blow up a balloon, two points on it will appear to be moving apart from each other even though they're stationary.
I believe this Forbes article is in agreement: https://www.forbes.com/sites/startswithabang/2018/02/10/ask-ethan-how-do-we-know-space-is-expanding/#7356826349e6 https://www.forbes.com/sites/startswithabang/2018/02/10/ask-...
- wahern 7y agoIt's also been described like a loaf of bread expanding, where stars are like raisins, except the loaf might be infinitely big. See https://en.wikipedia.org/wiki/Inflation_(cosmology) https://en.wikipedia.org/wiki/Inflation_(cosmology) and https://en.wikipedia.org/wiki/Shape_of_the_universe https://en.wikipedia.org/wiki/Shape_of_the_universe But that's also somewhat misleading as it gives the impression that it's just interstellar space (reinforcing the non-scientific connotation of space) that inflates. At some point even atoms may not be able to hold together. See https://en.wikipedia.org/wiki/Big_Rip https://en.wikipedia.org/wiki/Big_Rip Whether the Big Rip is true or not, it's useful as a supplemental illustration.
- Dylan16807 7y agoTo be clear, the big rip is only if expansion gets massively faster. At the current rate, the disturbance on matter is ridiculously negligibly small.