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 ...

Every time a coffee mug drops, a satellite orbits or an astronaut floats, we are watching the same phenomenon play out under very different disguises. For centuries we have treated gravity as the ...

As far as physicists have been able to determine, nature speaks two mutually unintelligible languages: one for gravity and one for everything else. Curves in the fabric of space-time tell planets and ...

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, ...