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, ...

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 ...

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 ...

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 ...

One of the most counter-intuitive notions in physics is that all objects fall at the same rate, regardless of mass, aka the equivalence principle. This was memorably illustrated in 1971 by NASA Apollo ...

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 ...

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 ...

Physicists in Germany have used an atomic interferometer to perform the most accurate ever test of the equivalence principle at the level of atoms. Sebastian Fray and colleagues at the Max Planck ...

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 ...