theoretical physics

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.

Spurred on by quantum experiments that scramble the ordering of causes and their effects, some physicists are figuring out how to abandon causality altogether.

A new study shows that extreme black holes could break the famous “no-hair” theorem, and in a way that we could detect.

Frank Wilczek has been at the forefront of theoretical physics for the past 50 years. He talks about winning the Nobel Prize for work he did as a student, his solution to the dark matter problem, and the God of a scientist.

The result highlights a fundamental tension: Either the rules of quantum mechanics don’t always apply, or at least one basic assumption about reality must be wrong.

It has been thought of as many things: a pointlike object, an excitation of a field, a speck of pure math that has cut into reality. But never has physicists’ conception of a particle changed more than it is changing now.