The prevailing assumption has been that Einstein's theory of gravity must be modified, or 'quantized', in order to fit within quantum theory. This is the approach of two leading candidates for a ...

Modern physics theories highlight the key role of horizons—boundaries beyond which information cannot reach an observer—in a variety of cosmological and gravitational phenomena. Two renowned examples ...

With the help of a new experiment, researchers have succeeded in confirming a ten-year-old theoretical study, which connects one of the most fundamental aspects of quantum mechanics -- the ...

Sound waves, light waves and other types of waves, generally spread freely through space and over time. In 1958, physicist ...

You might say it all started with a spot of hay fever. In June 1925, a young physicist named Werner Heisenberg retreated to the barren island of Helgoland in the North Sea, seeking respite from his ...

Quantum theory is fundamentally a probabilistic description of nature in which the outcomes of measurements are governed by the Born rule and encoded in complex amplitudes or density operators. Beyond ...

Imagine a physicist observing a quantum system whose behavior is akin to a coin toss: it could come up heads or tails. They perform the quantum coin toss and see heads. Could they be certain that ...

The original version of this story appeared in Quanta Magazine. In the fall of 2022, a Princeton University graduate student named Carolina Figueiredo stumbled onto a massive coincidence. She ...

Causal set theory proposes that spacetime is fundamentally composed of discrete elements ordered by a causal relation, replacing the smooth manifold of general relativity with a locally finite ...

A rewrite of quantum mechanics that includes the force of gravity could finally achieve one of physicists’ biggest goals and reveal the ultimate fuzziness of time ...

The original version of this story appeared in Quanta Magazine. Two blind spots torture physicists: the birth of the universe and the center of a black hole. The former may feel like a moment in time ...

Many quantum effects can be observed only when a small number of particles is studied—individual atoms, molecules or photons, ...