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physics

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.

Illustration of a bowl of dark energy on a weighing scale
Abstractions blog

Why the Tiny Weight of Empty Space Is Such a Huge Mystery

The amount of energy infusing empty space seems too small to explain without a multiverse. But physicists have at least one alternative left to explore.

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.

520px illustration for higgs fakes
condensed matter physics

Elusive Higgs-Like State Created in Exotic Materials

Two teams of physicists have created the “Higgs mode” – a link between particle physics and the physics of matter. The work could help researchers understand the strange behavior of deeply quantum systems.

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.

520px illustration for scale=free networks
network science

Scant Evidence of Power Laws Found in Real-World Networks

A new study challenges one of the most celebrated and controversial ideas in network science.

520px illustration of bottle beam
nuclear physics

Neutron Lifetime Puzzle Deepens, but No Dark Matter Seen

Two methods of measuring the neutron’s longevity give different answers, creating uncertainty in cosmological models. But no one has a clue what the problem is.

520px illustration for Quantum Supremacy
The Future of Quantum Computing

Quantum Algorithms Struggle Against Old Foe: Clever Computers

The quest for “quantum supremacy” – unambiguous proof that a quantum computer does something faster than an ordinary computer – has paradoxically led to a boom in quasi-quantum classical algorithms.

520px illustration for the bounce model theory
cosmology

How the Universe Got Its Bounce Back

Cosmologists have shown that it’s theoretically possible for a contracting universe to bounce and expand. The new work resuscitates an old idea that directly challenges the Big Bang theory of cosmic origins.