Atomic physics

Time was found to flow differently between the top and bottom of a single cloud of atoms. Physicists hope that such a system will one day help them combine quantum mechanics and Einstein’s theory of gravity.

For over two decades, physicists have pondered how the fabric of space-time may emerge from some kind of quantum entanglement. In Monika Schleier-Smith’s lab at Stanford University, the thought experiment is becoming real.

A team in Paris has made the most precise measurement yet of the fine-structure constant, killing hopes for a new force of nature.

Atomic clocks are letting physicists tighten the lasso around elusive phenomena such as dark matter.

The search for exotic new physical phenomena is being led by huge experiments like the Large Hadron Collider. But at the other end of the spectrum lie tabletop experiments — small-scale probes of hidden dimensions, dark matter and dark energy.