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quantum gravity

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 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.

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.

M theory and its six components
Abstractions blog

Why Is M-Theory the Leading Candidate for Theory of Everything?

The mother of all string theories passes a litmus test that, so far, no other candidate theory of quantum gravity has been able to match.

Edward Witten in his office at the Institute for Advanced Study in Princeton, New Jersey.
Q&A

A Physicist’s Physicist Ponders the Nature of Reality

Edward Witten reflects on the meaning of dualities in physics and math, emergent space-time, and the pursuit of a complete description of nature.

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.

Joe Polchinsky at the Kavli Institute
Thinking Places

Joe Polchinski’s Restless Pursuit of Quantum Gravity

The pot-stirring string theorist and quantum gravity theorist never sits still for long.

Naked singularities
quantum gravity

Where Gravity Is Weak and Naked Singularities Are Verboten

Recent calculations tie together two conjectures about gravity, potentially revealing new truths about its elusive quantum nature.