## Packages

To celebrate the anniversary of its proof, this collection of articles and videos explores one of the most beguiling theorems in maths.

*Women of Mathematics*photo exhibition.

Imagine your weight depended on the colour of your underwear! Something quite similar may be happening when you are measuring things in quantum physics. Find out more here...

Bees do it, rabbits do it, and luckily, we humans can do it too: explore the famous Fibonacci sequence!

In this busy time why not put your feet up and learn some maths in just a few minutes with this year's *Plus* advent calendar. Now what's behind today's door?

Traditionally, observers play no special role in physics. Like bird watchers in a perfect hide, we observe the outcome of experiments, or gaze at the stars through our telescopes, taking no part in the action. Modern physics, however, tells a different story ... find out more with these articles and videos.

Can the very act of observing something change what's being observed? This series of articles and videos explores some basic questions about the role of the observers in physics.

We all know what we mean when we say that something has happened — well, all except for theoretical physicists. That's because the notion of a "happening" becomes fuzzy when you go down to the foundations of the science. Find out more with these articles and videos.