Great reminder that you can find amazing moments of “A-ha-ness” in everyday places. Like when your legs buckle on an elevator.
When Einstein looked at those little gravity jolts, he saw into the very heart of the cosmos. They were the key to his “ah-ha” moment. He realized that gravity isn’t about forces, it’s about falling.
Gravity, Einstein saw, is what happens when you take away forces and let things go with the flow — the flow of space. Cut the cables on your elevator and what happens (other than a lot of yelling and panic)? Inside, everything appears to go weightless. During the fall you’d float like an astronaut in a space capsule.
That was how Einstein realized that apples don’t fall because of forces; they fall because that is what space wants them to do. Gravity is space bending and stretching like taffy. Even though you can never touch space you can see it has a shape just by watching how things fall.