Fundamental physics

Promise and controversy continues to surround string theory as a potential unified theory of everything. In the latest episode of The Joy of Why, Cumrun Vafa discusses his progress in trying to find good, testable models hidden among the ‘swampland’ of impossible universes.

Black hole and Big Bang singularities break our best theory of gravity. A trilogy of theorems hints that physicists must go to the ends of space and time to find a fix.

From living matter to molecules to elementary particles, the world is made of “chiral” objects that differ from their reflected forms.

Last year, an enormous map of the cosmos hinted that the engine driving cosmic expansion might be sputtering. Now physicists are back with an even bigger map, and a stronger conclusion.

Exactly 200 years ago, a French engineer introduced an idea that would quantify the universe’s inexorable slide into decay. But entropy, as it’s currently understood, is less a fact about the world than a reflection of our growing ignorance. Embracing that truth is leading to a rethink of everything from rational decision-making to the limits of machines.

A new experimental proposal suggests detecting a particle of gravity is far easier than anyone imagined. Now physicists are debating what it would really prove.

Curious connections between physics and math suggest to Latham Boyle that space-time may survive the jump to the next theory of reality.

A decade after the discovery of the “amplituhedron,” physicists have excavated more of the timeless geometry underlying the standard picture of how particles move.

A 1930s-era breakthrough is helping physicists understand how quantum threads could weave together into a holographic space-time fabric.