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How Einstein Lost His Bearings, and With Them, General Relativity
By 1913, Albert Einstein had nearly completed general relativity. But a simple mistake set him on a tortured, two-year reconsideration of his theory. Today, mathematicians still grapple with the issues he confronted.
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.
Astronomers Trace Radio Burst to Extreme Cosmic Neighborhood
A mysterious object that repeatedly bursts with ultra-powerful radio waves must live in an extreme environment — something like the one around a supermassive black hole.
Earliest Black Hole Gives Rare Glimpse of Ancient Universe
It weighs as much as 780 million suns and helped to cast off the cosmic Dark Ages. But now that astronomers have found the earliest known black hole, they wonder: How could this giant have grown so big, so fast?
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.