The original version of this story appeared in Quanta Magazine. The world of mathematics is full of unreachable corners, where unsolvable problems live. Now, yet another has been exposed. In 1900, the ...

In 1935, Albert Einstein, working with Boris Podolsky and Nathan Rosen, grappled with a possibility revealed by the new laws of quantum physics: that two particles could be entangled, or correlated, ...

Moral dilemmas are often undecidable. Which is to say, there are times when we lack solid rational grounds for choosing between two (or more) compelling courses of action. In those moments, after ...