This year marks the 100th anniversary of quantum mechanics. The theory describes the world at very small scales and is famously counter-intuitive. It suggests that the world is fundamentally random, that two particles can be in several places at once, and that they can be mysteriously linked even when they are very far apart. These things don't seem possible, but they are there, clear as day, in the mathematics that describes the theory, and they've also been confirmed in experiments.
To celebrate the theory's 100th birthday we bring together some of our introductory articles on the topic. Let your mind roam free and enjoy this marvellous combination of nature and mathematics!
To see all our content on quantum mechanics, click here.
Why quantum mechanics? — Towards the end of the 19th century people thought that physics was done and dusted. Over the next few decades, however, alarming cracks started to open up in the theory. This short article explores why a revolution was needed.
The double slit experiment — Here's a quick introduction to a famous experiment which confirms some of the stranger predictions of quantum mechanics: that light is simultaneously wave-like and particle-like and that the very act of looking at a quantum system can change it.
Who killed Schrödinger's cat? — Schrödinger's cat has become a well-known metaphor for mutually exclusive things happening at the same time. Here's a quick look at the origin of the famous feline.
A ridiculously short introduction to some very basic quantum mechanics — This article does what it says on the tin, to the best of our ability.
Heisenberg's uncertainty principle — The uncertainty principle is one of the central results of quantum mechanics. Here's a brief introduction which also shows how the principle drops out of the mathematics.
Schrödinger's equation: what is it, what does it do, and what does it mean? — If you are up for a bit more of a challenge, here's a three-part article about one of the central equations of quantum mechanics. You will learn what the equation looks like, some of what it can tell us, and how we might interpret its consequences (could there be many parallel universes?)
A brief history of quantum field theory — For another deep-dive, this series of accessible articles traces the history of quantum field theory, from its inception in quantum mechanics to the tantalising questions that are still open today. It's a story of pain and triumph, hardship and success. Happy reading!