# 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.

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.