# Recursive Book Cover Is Recursive

The cover art for Paul Halmos' book on Naive Set Theory plays with the self-referential nature of Russel's Paradox, to humorous visual effect.

The cover art for Paul Halmos' book on Naive Set Theory plays with the self-referential nature of Russel's Paradox, to humorous visual effect.

Our universe appears to be bound by a finite set of laws, yet we often talk about things that go on for an eternity. "Infinity" is a strange idea. But it's crucial if you want to understand anything from philosophy to mathematics. Here’s why.

Minute Physics' Henry Reich takes a break from physics to drop some maths knowledge. Using some basic tenets of set theory, Reich explains how we know that one infinity can be bigger than another.

How's your Monday coming along? Pretty rough? Well it's about to get a little hairier. If I'm not mistaken, this self-referential brain teaser is a play on the age-old Liar's paradox, (or, for those of you familiar with set theory, Russell's paradox), reframed in the form of a multiple-choice question.

The notion of infinity is fundamentally beyond the human ability to comprehend, but that hasn't stopped mathematicians from trying. So just what is infinity, and why is there more than one of them? And just what *is* infinity plus one?

Benoit Mandelbrot, who died last week at 85, was to math what Carl Sagan was to astrophysics. He wasn't just a researcher; he popularized scientific thought. And he's best known for bringing fractal mathematics to the masses.