Theoretical physics

Investigations of the simplest possible clocks have revealed their fundamental limitations — as well as insights into the nature of time itself.

The five-decade-old paradox — long thought key to linking quantum theory with Einstein’s theory of gravity — is falling to a new generation of thinkers. Netta Engelhardt is leading the way.

Theorists are in a frenzy over “fractons,” bizarre, but potentially useful, hypothetical particles that can only move in combination with one another.

The root of today’s quantum revolution was John Stewart Bell’s 1964 theorem showing that quantum mechanics really permits instantaneous connections between far-apart locations.

The Standard Model is a sweeping equation that has correctly predicted the results of virtually every experiment ever conducted, as Quanta explores in a new video.

Chiara Marletto is trying to build a master theory — a set of ideas so fundamental that all other theories would spring from it. Her first step: Invoke the impossible.

Today’s long-anticipated announcement by Fermilab’s Muon g-2 team appears to solidify a tantalizing conflict between nature and theory. But a separate calculation, published at the same time, has clouded the picture.

The zoo of spontaneously emerging particlelike entities known as quasiparticles has grown quickly and become more and more exotic. Here are a few of the most curious and potentially useful examples.

An unexpected superconductor was beginning to look like a fluke, but a new theory and a second discovery have revealed that emergent quasiparticles may be behind the effect.