Gravity is the force of action between two objects. It’s called a natural force because it acts at a distance rather than needing to be in contact. Gravity is the force that holds us down on Earth and ...

All of the objects in our solar system are acted upon by forces. Forces are pushes or pulls. Every force has both a strength and a direction. Applying a force on something–like pushing a toy car–can ...

Physicists have traced three of the four forces of nature — the electromagnetic force and the strong and weak nuclear forces — to their origins in quantum particles. But the fourth fundamental force, ...

Unifying quantum mechanics with general relativity is the ultimate dream — or nightmare — of physics. It would be a way to finally describe the force of gravity with the tools of quantum mechanics, ...