Find the number x that satisfies two interesting properties.
What's that we hear? Sleigh bells! What's that we smell? Chestnuts roasting on an open fire! What can that mean? Christmas is coming! Celebrate the countdown with the Plus advent calendar featuring our favourite mathematical moments from 2012. Now, what's behind today's door...?
Mathematicians and psychologists don't cross paths that often and when they do you wouldn't expect it to involve an (apparently) unassuming puzzle like the Tower of Hanoi. Yet, the puzzle holds fascination in both fields.
Ocean waves are not moving walls of water. Instead, it's some kind of energy that moves along. But then, what happens to the water itself? This isn't just an idle question to ponder while watching the ocean — its answer may help protect us from it too. And it requires some sophisticated maths.
If there's one bit of maths you remember from school it's probably Pythagoras' theorem. But what's a Pythagorean triple? How many triples are there and how do you find them? And what about quadruples, quintuples, sextuples....
