Could there be more than three?

A possible way of resolving the greatest problem of physics.

Explore the biggest problem in modern physics.

There are limits to how much you can simultaneously squeeze the quantum fuzziness of an electron's position and momentum

A very strange way of explaining away the strangeness of quantum mechanics.

At the heart of modern physics lurks a terrible puzzle: the two main theories that describe the world we live in just won't fit together.

In the 1920s the Austrian physicist Erwin Schrödinger came up with what has become the central equation of quantum mechanics. It tells you all there is to know about a quantum physical system and it also predicts famous quantum weirdnesses such as superposition and quantum entanglement. In this, the first article of a three-part series, we introduce Schrödinger's equation and put it in its historical context.

Most of us think that we have the capacity to act freely. Our sense of morality, our legal system, our whole culture is based on the idea that there is such a thing as free will. It's embarrassing then that classical physics seems to tell a different story. And what does quantum theory have to say about free will?