I obviously get what it is: apple falls from the tree, etc. And I think I more or less get how it is: Newtonian mechanics, general relativity, curved spacetime, etc.
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I wish I had a better sense of where gravity comes from. Anyone have good intuition that they could explain?
I obviously get what it is: apple falls from the tree, etc. And I think I more or less get how it is: Newtonian mechanics, general relativity, curved spacetime, etc.
But I do not get why it is. Why does gravity exist? Why do large accumulations of mass naturally pull other mass toward them? 🧐
One theory I’ve heard is that there’s a universal field, like the Higgs, with particles traveling in all directions and colliding with mass. If you’re near a massive body like a star or planet or moon, it blocks some particles on its side from hitting you, but not from the other side, so the net effect pushes you toward it.
That would make gravity related to volume instead of mass, though, which obviously isn’t right. Still, I don’t remember hearing any other explanations. Does anyone know of any?
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@snarfed.org I meant to investigate this thoroughly as a teenager, and got to a book on general relativity -- that was in the STEM desert long before the internet -- whose math was waaayyy above my league at the time. They had me at "Einsteinian summation convention" with volume integrals when I had barely seen a volume integral before.
P.S. A Why question here may not make much sense. IMHO to be able to form a Why answer, you'd have to step out of the descriptive system of physics.
