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Black Hole Echoes Would Reveal Break With Einstein’s Theory
Gravitational waves have opened up new ways to test the properties of black holes — and Einstein’s theory of gravity along with them.
Why Stephen Hawking’s Black Hole Puzzle Keeps Puzzling
The renowned British physicist, who died at 76, left behind a riddle that could eventually lead his successors to the theory of quantum gravity.
Physicists Find a Way to See the ‘Grin’ of Quantum Gravity
A recently proposed experiment would confirm that gravity is a quantum force.
Physicists Mourn Joe Polchinski, Developer of Deep Ideas and Paradoxes
The theoretical physicist Joe Polchinski, who died February 2, left a tremendous professional and personal legacy, says a friend and collaborator.
Why an Old Theory of Everything Is Gaining New Life
For decades, physicists have struggled to create a quantum theory of gravity. Now an approach that dates to the 1970s is attracting newfound attention.
Why Is M-Theory the Leading Candidate for Theory of Everything?
The mother of all string theories passes a litmus test that, so far, no other candidate theory of quantum gravity has been able to match.
A Physicist’s Physicist Ponders the Nature of Reality
Edward Witten reflects on the meaning of dualities in physics and math, emergent space-time, and the pursuit of a complete description of nature.
Newfound Wormhole Allows Information to Escape Black Holes
Physicists theorize that a new “traversable” kind of wormhole could resolve a baffling paradox and rescue information that falls into black holes.