The accelerating expansion of the universe is usually explained by an invisible force known as dark energy. But a new study ...

Every time a coffee mug drops, a satellite orbits or an astronaut floats, we are watching the same phenomenon play out under ...

A variation on the theory of quantum gravity — the unification of quantum mechanics and Einstein's general relativity — could help solve one of the biggest puzzles in cosmology, new research suggests.

Quantum theory and Einstein's theory of general relativity are two of the greatest successes in modern physics. Each works ...