Mr and Mrs Magnus are a happy gnome couple. Unfortunately, foreseeing that they will be unable to keep up with their rising mortgage repayments, they've been forced to move into my back garden, where they've acquired a plot to build a house on. Gnome by-laws state that the total number of bricks used in any construction project must be 177 or planning permission will not be granted. How can they manage to stick to the rules?
When your eyes see a picture they send an image to your brain, which your brain then has to make sense of. But sometimes your brain gets it wrong. The result is an optical illusion. Similarly in logic, statements or figures can lead to contradictory conclusions, which we call paradoxes. This article looks at examples of geometric optical illusions and paradoxes and gives explanations of what's really going on.
What happens when magnetic fields get tangled up in knots? This does happen in the Sun's atmosphere and mathematical models predict that once the magnetic field becomes tangled, it must retain some vestige of this complexity for a long time. This enables the storage of vast quantities of energy. In this article I will outline how the notion of magnetic topology helps us to understand the physical situation and draw such conclusions.
In this article we present a set of unusual dice and a two-player game in which you will always have the advantage. You can even teach your opponent how the game works, yet still win again!
We'll also look at a new game for three players in which you can potentially beat both opponents — at the same time!
As London is heading for the 2012 Olympics, it's not just athletes who are gearing up for action. Engineers, too, are working hard to produce the cutting-edge sporting equipment that guarantees record performances. If you're a tennis player, your most important piece of equipment is your racket. Over recent decades new materials have made tennis rackets ever bigger, lighter and more powerful. So what kind of science goes into designing new rackets?
England's performance in the World Cup last summer was thankfully overshadowed by the attention given to Paul the octopus, who was reported as making an unbroken series of correct predictions of match winners. David Spiegelhalter looks at Paul's performance in an attempt to answer the question that (briefly) gripped the world: was Paul psychic?