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black holes

520px illustration for black hole echoes
Quantized Columns

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.

Photo of Stephen Hawking in 1979 in Princeton, New Jersey.
Abstractions blog

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.

Photograph of Albert Einstein in his office at the University of Berlin, published in the USA in 1920.
Abstractions blog

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.

Animated illustration of a black hole in a cube of jelly
mathematical physics

To Test Einstein’s Equations, Poke a Black Hole

Two teams of researchers have made significant progress toward proving the black hole stability conjecture, a critical mathematical test of Einstein’s theory of general relativity.

An illustration of gravity as particles
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.

520px photo of Joe Polchinski
Quantized Columns

Physicists Mourn Joe Polchinski, Developer of Deep Ideas and Paradoxes

The theoretical physicist Joe Polchinski, who died Feb. 2, left a tremendous professional and personal legacy, says a friend and collaborator.

Illustration for Extreme Radio Bursts
astrophysics

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.

Magellan Baade telescope and CMB illustration
astrophysics

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?

Plunge Into A (Virtual Reality) Black Hole
Multimedia

Plunge Into a (Virtual Reality) Black Hole

Join a fleet of robotic probes on a one-way virtual-reality trip into the abyss of a massive black hole.