Somewhere between the microscopic realm of elementary particles and the macroscopic world of human beings, something strange ...

Superfluid helium has produced a narrow muonium beam, opening a path to test whether exotic particles fall like ordinary matter.

Physicists have directly linked quantum mechanics and Einstein's gravity theory. An experiment used ultracold atoms in ...

Scientists have found a new way to create a controlled beam of muonium, an exotic atom containing a heavier cousin of the electron. The advance could allow researchers to test for the first time ...

A new experiment found that a falling quantum wave behaves just as Einstein’s equivalence principle predicts. The result ...

Physicists have directly observed a long-predicted quantum effect of gravity, putting one of Einstein’s foundational ideas to ...

Does gravity act equally on all particles in the universe, or are there differences between ordinary and exotic matter?

Just over a week ago, European physicists announced they had measured the strength of gravity on the smallest scale ever. In a clever tabletop experiment, researchers at Leiden University in the ...

Just over a week ago, European physicists announced they had measured the strength of gravity on the smallest scale ever. In a clever tabletop experiment, researchers at Leiden University in the ...

For more than a century, quantum mechanics and Albert Einstein’s theory of general relativity have each passed countless tests, but physicists have struggled to reconcile the two. Now, scientists in ...