Gravity is the OG of the forces of Nature. Historically it was the first to be discovered and described scientifically, yet it’s the most challenging to study. Even though gravity governs the orbits ...

For the first time in space, scientists have produced a mixture of two quantum gases made of two types of atoms. Accomplished with NASA's Cold Atom Laboratory aboard the International Space Station, ...

Galileo’s most famous experiment has taken a trip to outer space. The result? Einstein was right yet again. The experiment confirms a tenet of Einstein’s theory of gravity with greater precision than ...

At the heart of Einstein’s theory of gravity (general relativity) is the equivalence principle. The equivalence principle says that there is no difference between being stationary and subject to ...

One way to explain the puzzling acceleration of the universe is to modify Einstein’s theory of general relativity to create a fifth force that can account for the acceleration. These theories have to ...

If you simultaneously drop a feather and a bowling ball in a vacuum, they’ll hit the ground at the same time. In other words, despite their mass, they’re affected by a gravitational field in exactly ...

How Einstein's equivalence principle extends to the quantum world has been puzzling physicists for decades, but a research team has now found the key to this question. How Einstein's equivalence ...

Scientists from Garching and Tuebingen investigated the equivalence principle for two different rubidium isotopes with an atom interferometer, a quantum mechanical device. They stored a billion ...

In the late 1500s, the Italian scientist Galileo Galilei conceived of an experiment that changed a foundation of physics. He mulled — and by some accounts actually tested — what would happen if two ...

The physics of the microrealm involves two famous and bizarre concepts: The first is that prior to observation, it is impossible to know with certainty the outcome of a measurement on a particle; ...