I often hear that gravity is not a force, but simply the curvature of spacetime. A common example given is having a heavy ball placed on a rubber sheet. The ball sinks, distorting the sheet. Therefore, other “orbiting” objects will also tend to roll towards the sunken part.
What I can’t understand is, what causes the objects to “fall” anyway? On earth, that’s just the planet’s gravity. If you did the same experiment on space the objects wouldn’t roll down. So how is this an explanation of gravity as a curvature, when it requires a *force* to work? Is there a better explanation? Am I just missing something?
In: Physics
The simplest explanation of gravity is that it IS a force of attraction between two objects with mass. This explanation is pretty much good enough for anything other than things moving at very high speeds, very long distances, very small particles, and for massive objects like stars.
Any other explanation is not so easy without resorting to reasonably advanced mathematical models.
Latest Answers