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 ...

The original version of this story appeared in Quanta Magazine. Two blind spots torture physicists: the birth of the universe and the center of a black hole. The former may feel like a moment in time ...

In the zero-gravity airplanes or vomit comet, why does stuff behave like there is no gravity when it is just falling? – Austin B., 11, Scranton, Pennsylvania I have flown many times in zero-gravity ...

WHEN the two most important figures in your life don’t get along, there will always be trouble. Just ask physicists: the two most totemic theories in their field are fundamentally incompatible, and ...