Why does time have a direction?

To create energy from information you would need to break the second law of thermodynamics — that's impossible in the real world, but could theories that do break it shed light on why nature is the way it is?

Like spirals and flowers? Then you'll love polar coordinates and the pretty pictures they allow you to draw!

By the 1970s physicists had successfully tamed three of the fundamental forces using a sophisticated construct called quantum field theory. The trouble was that the framework seemed to fall apart when you looked at very high or very low energy scales. So how could these be thought of as valid theories? It's a question physicists are still grappling with today.

Can we always find order in systems that are disordered? If so, just how large does a system have to be to contain a certain amount of order?

The early 1950s were an experimental gold mine for physicists, with new particles produced in accelerators almost every week. Yet the strong nuclear force that acted between them defied theoretical description, sending physicists on a long and arduous journey that culminated in several Nobel prizes and the exotic concept of "asymptotic freedom".

There's no doubt that information is power, but could it be converted into physical energy you could heat a room with or run a machine on? In the 19th century James Clerk Maxwell invented a hypothetical being — a "demon" — that seemed to be able to do just that. The problem was that the little devil blatantly contravened the laws of physics. What is Maxwell's demon and how was it resolved?

How a cute 18th century puzzle laid the foundations for one of the most modern areas of maths: network theory.

How big is the Universe? Where did it come from and where is it going? Why is it the way it is? These are just some of the questions cosmologists study.