Gravity behaves predictably in your daily life. Drop a ball, and it falls. Planets loop around stars. On paper, the same rules should also govern matter spread across the universe. But the farther ...

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 ...

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 ...