> gravity isn't really a force Yeah, this fact made me cringe at explanation #2: the guy keeps saying things like "gravity is the only force that is felt by al

> gravity isn't really a force Yeah, this fact made me cringe at explanation #2: the guy keeps saying things like "gravity is the only force that is felt by all kinds of matter". Stuff doesn't "feel" gravity; it's not a force, it's just the shape of spacetime. Also, gravity doesn't just affect matter; photons are not matter, but are affected by the curvature of spacetime (i.e. gravity). /me not a physicist; but I'm not a baby either, and I don't appreciate babytalk oversimplifications.