How can nothing expand? Isn’t space made of nothing? You can’t have 5 pounds of space.
In: Physics
I think part of the confusion here is because of the terms. When we say space is expanding, it means space as in space-time, the fundamental idea of where things exist, not space as in specifically the area in between planets where there’s almost nothing. The second is included in the first, but it’s more general than that. If everything is observably moving away from everything else in every direction, then this must mean that there is more space as in “area to exist” in between them. Now practically this also means there is more space (the vacuum) but that’s because of space (the area of existence) expanding, not a fundamental part of specifically the vacuum areas.
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