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gravity
quantum gravity
Black Hole's Orbiting Ring of Light Could Encrypt Its Inner Secrets
Physicists have discovered that the ring of photons orbiting a black hole exhibits a special kind of symmetry, hinting at a deeper meaning.
general relativity
Mass and Angular Momentum, Left Ambiguous by Einstein, Get Defined
Surprising as it may sound, 107 years after the introduction of general relativity, the meanings of basic concepts are still being worked out.
The Joy of Why
Where Do Space, Time and Gravity Come From?
Einstein’s description of curved space-time doesn’t easily mesh with a universe made up of quantum wavefunctions. Theoretical physicist Sean Carroll discusses the quest for quantum gravity with host Steven Strogatz.
quantum physics
Massive Black Holes Shown to Act Like Quantum Particles
Physicists are using quantum math to understand what happens when black holes collide. In a surprise, they’ve shown that a single particle can describe a collision’s entire gravitational wave.
Q&A
In Search of Cracks in Albert Einstein’s Theory of Gravity
Celia Escamilla-Rivera is combining large data sets with supercomputers to test general relativity against its little-known competitors.
quantum gravity
How Gravity Is a Double Copy of Other Forces
An enigmatic connection between the forces of nature is allowing physicists to explore gravity’s quantum side.
quantum gravity
Quantum Mischief Rewrites the Laws of Cause and Effect
Spurred on by quantum experiments that scramble the ordering of causes and their effects, some physicists are figuring out how to abandon causality altogether.
2020 in Review
The Year in Physics
Featuring paradoxical black holes, room-temperature superconductors and a new escape from the prison of time.
Abstractions blog
A New Cosmic Tension: The Universe Might Be Too Thin
Cosmologists have concluded that the universe doesn’t appear to clump as much as it should. Could both of cosmology’s big puzzles share a single fix?