theoretical physics

The past and the future are tightly linked in conventional quantum mechanics. Perhaps too tightly. A tweak to the theory could let quantum possibilities increase as space expands.

Physicists have discovered that the ring of photons orbiting a black hole exhibits a special kind of symmetry, hinting at a deeper meaning.

Quantum field theory may be the most successful scientific theory of all time, but there’s reason to think it’s missing something. Steven Strogatz speaks with theoretical physicist David Tong about this enigmatic theory.

The key to understanding the origin and fate of the universe may be a more complete understanding of the vacuum.

A hidden link has been found between two seemingly unrelated particle collision outcomes. It’s the latest example of a mysterious web of mathematical connections between disparate theories of physics.

Surprising as it may sound, 107 years after the introduction of general relativity, the meanings of basic concepts are still being worked out.

Decades after a Tanzanian teenager initiated study of the “Mpemba effect,” the effort to confirm or refute it is leading physicists toward new theories about how substances relax to equilibrium.

Quantum computers may derive their power from the “magical” way that properties of particles change depending on the context.

The second law of thermodynamics is among the most sacred in all of science, but it has always rested on 19th century arguments about probability. New arguments trace its true source to the flows of quantum information.