What's stopping us from building useful quantum computers? And how long until we'll have them?

An untapped resource could provide the magic needed for quantum computation — and perhaps even open the door to time travel.

Here's a brief introduction to the possible future of computing.

Why it's hard to build quantum computers and what can be done about it.

Some neat number tricks using numbers read backwards.

Eleven makes multiplication easy.

The impossible becomes possible when you move into the third dimension.

A quick look at an ancient problem.

A mathematical "paradox" explains why more roads don't necessarily mean fewer traffic jams.

Why there are only three regular polygons you can tile a wall with.

What does packing balls in higher dimensions have to do with getting your message across?

What is dark matter and how can the LHC find it?