What's up in

quantum gravity

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.
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.

For decades, physicists have struggled to create a quantum theory of gravity. Now an approach that dates to the 1970s is attracting newfound attention.
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.

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

Physicists theorize that a new “traversable” kind of wormhole could resolve a baffling paradox and rescue information that falls into black holes.
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.

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.
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.

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

Joe Polchinski’s Restless Pursuit of Quantum Gravity

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

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

A decades-old method called the “bootstrap” is enabling new discoveries about the geometry underlying all quantum theories.
theoretical physics

Physicists Uncover Geometric ‘Theory Space’

A decades-old method called the “bootstrap” is enabling new discoveries about the geometry underlying all quantum theories.