Physics

A radical theory predicting the existence of “time crystals” — perpetual motion objects that break the symmetry of time — is being put to the test.

Glass and other strange materials have long confounded textbook definitions of what it means to be solid. Now, two groups of physicists propose a new solution to the riddle.

Three “extremely large telescopes” poised to begin observations within a decade could help answer some of the universe’s oldest and best-kept secrets.

If a new hypothesis about black hole firewalls proves correct, at least one of three cherished notions in theoretical physics must be wrong.

Using supercomputers and new mathematical techniques, physicists are working to reveal how the Hoyle state atomic nucleus gives rise to the light elements that enable life, and how it drives the evolution of stars.

As the elegant theory of supersymmetry continues to fail experimental tests, physicists debate whether to change course and what the future holds for particle physics.