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gravity

An illustration of an airplane with its contrails coming out in front of it.
quantum gravity

Quantum Mischief Rewrites the Laws of Cause and Effect

March 11, 2021

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

December 23, 2020

Featuring paradoxical black holes, room-temperature superconductors and a new escape from the prison of time.

Distorted galaxies
Abstractions blog

A New Cosmic Tension: The Universe Might Be Too Thin

September 8, 2020

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?

Claudia de Rham portrait
Q&A

The Physicist Who Slayed Gravity’s Ghosts

August 18, 2020

Claudia de Rham showed how theories of “massive gravity” could potentially get rid of the need for dark energy.

An apple being jostled by gravitons
gravitational waves

How the Bits of Quantum Gravity Can Buzz

July 23, 2020

New calculations show how hypothetical particles called gravitons would give rise to a special kind of noise.

A falling apple.
Abstractions blog

Why Gravity Is Not Like the Other Forces

June 15, 2020

We asked four physicists why gravity stands out among the forces of nature. We got four different answers.

A black hole shooting thunderbolts.
quantum gravity

Black Hole Paradoxes Reveal a Fundamental Link Between Energy and Order

May 28, 2020

By chewing on the problems posed by “extremal” black holes, physicists have exposed a surprising and universal connection between energy and entropy.

Animation of black hole formation.
mathematical physics

New Math Proves That a Special Kind of Space-Time Is Unstable

May 11, 2020

Einstein’s equations describe three canonical configurations of space-time. Now one of these three — important in the study of quantum gravity — has been shown to be inherently unstable.

Animation of a black hole rotating.
Abstractions blog

Black Hole Singularities Are as Inescapable as Expected

December 2, 2019

For the first time, physicists have calculated exactly what kind of singularity lies at the center of a realistic black hole.