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Not true. For example we could be surrounded by a sphere of uniform infinite density, in which case our atoms wouldn't be pulled in either direction.
by danra 3y ago
Not true. For example we could be surrounded by a sphere of uniform infinite density, in which case our atoms wouldn't be pulled in either direction.
- swamp40 3y agoIf the sphere had infinite density, wouldn't that mean that every atom in the universe would be inside? So how could our atoms be outside?
- zdragnar 3y agoFor those of us like myself who are terribly naive, why wouldn't that just cause all of the atoms to be torn apart? Unless the sphere were infinitely far away, only the center point would be in balance, and everything else would be immediately sucked to the edge of the sphere. If the sphere's radius was infinite, that might explain the expansion of the universe itself, but not the presence of infinite density within the universe itself.
- consilient 3y ago> Unless the sphere were infinitely far away, only the center point would be in balance This is false. https://en.wikipedia.org/wiki/Divergence_theorem https://en.wikipedia.org/wiki/Divergence_theorem
- Dylan16807 3y agoWhen you do the math for gravity inside a shell of material, the quadratic falloff exactly counteracts the distances and the total pull is exactly zero. https://en.wikipedia.org/wiki/Shell_theorem https://en.wikipedia.org/wiki/Shell_theorem