Natalie Wolchover

Ultrahigh-energy cosmic rays twist and turn on their way to Earth, which has made it nearly impossible to identify the colossal monsters that create them.

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.

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

Twenty years ago, physicists set out to investigate a mysterious asymmetry in the proton’s interior. Their results, published today, show how antimatter helps stabilize every atom’s core.

Micrometeorites constantly fall on every corner of Earth. Matthew Genge is using these shards of interplanetary space to understand Earth and its place in the solar system.

We don’t know why the universe appears to be expanding faster than it should. New ultra-precise distance measurements have only intensified the problem.

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

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.

We’ve created a new way to explore the fundamental constituents of the universe.