By resolving a paradox about light in a box, researchers hope to clarify the concept of energy in quantum theory.
Physicists have been busy exploring how our universe might emerge like a hologram out of a two-dimensional sheet. New clues have come from the symmetries found on an infinitely distant “celestial sphere.”
The “gravitational memory effect” predicts that a passing gravitational wave should forever alter the structure of space-time. Physicists have linked the phenomenon to fundamental cosmic symmetries and a potential solution to the black hole information paradox.
Quantum bits are fussy and fragile. Useful quantum computers will need to use an error-correction technique like the one that was recently demonstrated on a real machine.
Time was found to flow differently between the top and bottom of a single cloud of atoms. Physicists hope that such a system will one day help them combine quantum mechanics and Einstein’s theory of gravity.