Physics

A century ago, the Stern-Gerlach experiment established the truth of quantum mechanics. Now it’s being used to probe the clash of quantum theory and gravity.

Mathematicians prove a theorem that illuminates the geometry of universes with tiny amounts of mass.

For 50 years, physicists have understood current as a flow of charged particles. But a new experiment has found that in at least one strange material, this understanding falls apart.

Scientists have recently discovered scores of free-floating worlds that defy classification. The new observations have forced them to rethink their theories of star and planet formation.

In the rumbles and groans of underwater volcanoes, Jackie Caplan-Auerbach finds her favorite harmonies — and clues to the Earth’s interior.

The moons orbiting Jupiter and Saturn appear to have subsurface oceans — tantalizing targets in the search for life beyond Earth. But it’s not clear why these seas exist at all.

After identifying interlocking symmetries in mammalian cells, scientists can describe some tissues as liquid crystals — an observation that lays the groundwork for a fluid-dynamic theory of how tissues move.

What makes a quantum computer more powerful than a classical computer? It’s a surprisingly subtle question that physicists are still grappling with, decades into the quantum age.

Eugenio Calabi, who died on September 25, conceived of novel geometric objects that later became fundamental to string theory.