Article
Defying gravity: The uphill roller
What goes up must come down — or does it? Find out how to cheat gravity with Julian Havil.
Moving rings to another peg in the fewest moves.
You've probably seen pictures of the famed Mandelbrot set and its mysterious cousins, the Julia sets. In this article Robert L. Devaney explores the maths behind these beauties and shows that they're loaded with mathematical meaning.