Why does Einsteins theory of relativity imply that gravity is a nonexistent force?
Einstein thought about gravity in a way that made it quite clear. Think of it this way: When you are subjected to a force, you can feel it. When you accelerate in a car, the forces applied by the engine push you back in your seat. Your hat flies off, your hair blows back. If you push against an object with your hand, you can feel the reaction force on your hand and in your arm. However, when you are in free fall, you feel no such forces. You float with no sense of any force acting on you, although you may be accelerating downward due to the “force” of gravity. So clearly, gravity is different. It creates acceleration, but there is no obvious force acting at all. Einstein’s famous thought experiment on this subject involved a rocket (actually, he used an elevator, because there were no manned rockets then) with no windows and no instruments simply standing upright on the ground. An astronaut stands on the floor of the spacecraft, but he cannot see outside. He feels 1G acceleration actin
