Kevin Hartnett

Kevin Hartnett

Contributing Writer

Latest Articles

How Shannon Entropy Imposes Fundamental Limits on Communication

September 6, 2022

What’s a message, really? Claude Shannon recognized that the elemental ingredient is surprise.

A Question About a Rotating Line Helps Reveal What Makes Real Numbers Special

July 26, 2022

The Kakeya conjecture predicts how much room you need to point a line in every direction. In one number system after another — with one important exception — mathematicians have been proving it true.

Surfaces So Different Even a Fourth Dimension Can’t Make Them the Same

June 16, 2022

For decades mathematicians have searched for a specific pair of surfaces that can’t be transformed into each other in four-dimensional space. Now they’ve found them.

Mathematicians Clear Hurdle in Quest to Decode Primes

January 13, 2022

Paul Nelson has solved the subconvexity problem, bringing mathematicians one step closer to understanding the Riemann hypothesis and the distribution of prime numbers.

How Tadayuki Watanabe Disproved a Major Conjecture About Spheres

October 26, 2021

Watanabe invented a new way of distinguishing shapes on his way to solving the last open case of the Smale conjecture, a central question in topology about symmetries of the sphere.

In Topology, When Are Two Shapes the Same?

September 28, 2021

As topologists seek to classify shapes, the effort hinges on how to define a manifold and what it means for two of them to be equivalent.

New Math Book Rescues Landmark Topology Proof

September 9, 2021

Michael Freedman’s momentous 1981 proof of the four-dimensional Poincaré conjecture was on the verge of being lost. The editors of a new book are trying to save it.

Proof Assistant Makes Jump to Big-League Math

July 28, 2021

Mathematicians using the computer program Lean have verified the accuracy of a difficult theorem at the cutting edge of research mathematics.

New Shape Opens ‘Wormhole’ Between Numbers and Geometry

July 19, 2021

Laurent Fargues and Peter Scholze have found a new, more powerful way of connecting number theory and geometry as part of the sweeping Langlands program.