“One of the most beautiful ideas in Einstein’s gravity theory is that geometry isn’t just mathematics: it’s also physics. Specifically, Einstein’s equations show that the more matter space contains, the more curved space gets.
This curvature of space causes things to move not in straight lines, but in a motion that curves toward massive objects—thus explaining gravity as a manifestation of geometry.”

Quote from “Our Mathematical Universe: My Quest for the Ultimate Nature of Reality” by Prof Max Tegmark