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gravity

Photo of the cosmos by the multi-lensed Dragonfly telescope
Abstractions blog

A Victory for Dark Matter in a Galaxy Without Any

Paradoxically, a small galaxy that seems to contain none of the invisible stuff known as “dark matter” may help prove that it exists.

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.

An illustration of gravity as particles
gravity

Physicists Find a Way to See the ‘Grin’ of Quantum Gravity

A recently proposed experiment would confirm that gravity is a quantum force.

520 Illustration for Quantum Gravity
Quantized Columns

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.

A wormhole split in two with swirls of blue on one side and swirls of pink on the other with a ringed planet in the background.
theoretical physics

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.

Emergent reductionism flower
Quantized Columns

To Solve the Biggest Mystery in Physics, Join Two Kinds of Law

Reductionism breaks the world into elementary building blocks. Emergence finds the simple laws that arise out of complexity. These two complementary ways of viewing the universe come together in modern theories of quantum gravity.

Juan Maldacena
Thinking Places

Juan Maldacena, Pondering Quantum Gravity by the Pond

One of the world’s preeminent theoretical physicists seeks a quiet place to think.

Dwarf irregular galaxy
Abstractions blog

Researchers Check Space-Time to See if It’s Made of Quantum Bits

The newly developed theory of emergent gravity, proposed as an alternative to dark matter, struggles in one of its first trials.