The Universe, so physicists tell us, is governed by a few basic laws of nature. But how can that be? How can the wonderfully complex world around us be governed by a few simple rules? This collection of articles, videos and a podcast explores this question. We'll see what differentiates laws of nature from their outcomes, how the complexity of the world conceals elegant mathematical symmetries, and how chaos can arise from order.

*These articles and videos are part of our Stuff happens: The physics of events project. *

### Articles

Laws and disorder — What is a law of nature and how can simple laws create a complex Universe? This short introduction has some answers.

Order behind chaos — It may not seem that way, but behind the complicated world of appearances lie elegant mathematical symmetries. This introductory article explores the concept of symmetry and why it is so important in physics.

Symmetry making and symmetry breaking — This articles takes a deeper look at the role of symmetry in physics, exploring how, and why, it helps physicists to predict things about the Universe that might otherwise remain hidden.

Chaos from order — This article explores how simple rules can lead to very complex outcomes, taking us into the realm of chaos theory.

### Videos

How can the laws of nature be simple when the world is so complex? Mathematician and cosmologist John D. Barrow gives a two-minute explanation.

How did physicists know that the Higgs boson existed before they saw it? Because the symmetries of nature dictated that it should do. John D. Barrow explores the role of symmetry in physics and why it provides such a powerful tool.

How can complexity emerge from simple rules? John D. Barrow gives a quick introduction to mathematical chaos.

So is the world simple or complex? It depends on how you look at it. This video contains the entire interview with John D. Barrow, from which the above clips were taken.

## What determines the constants used in the laws of nature?

For example, what determines the speed of light in a vacuum? Or the gravity constant of forces on masses? Or absolute zero temperature?