A HITCH HIKER'S GUIDE TO THE QUANTUM WORLD

Quantum physics is confusing. Really confusing. You just won't believe how vastly, hugely, mindbogglingly confusing it is. Fortunately, scientists have been exploring it for years now and are, finally, beginning to make some sense of it all

- by PHILIP BALL

In the same way that “space is big” (as described in Douglas Adams’s The Hitchhiker’s Guide to the Galaxy), quantum physics is confounding.

Science’s best minds have been puzzling away at it for over a century, pawing at the subject like Schrödinger’s cat playing with a ball of cosmic string. But the bafflement is beginning to give way to understanding and we’re starting to get a grasp on not only what quantum physics could mean, but what uses it could be put to.

Here are just a few suggestions for entries in what could be an early draft of a hitchhiker’s guide to the quantum world. Just remember: don’t panic!

QUANTUM INTERNET

Entangled encryption and a quantum cloud could change how we share data

In the 1980s, researchers pointed out something intriguing: the laws of quantum physics should permit information that has been encoded in quantum objects - like photons, the 'quantum particles' of light - to be sent from one person to another in a totally secure way. By connecting the transmitted particles via a phenomenon called quantum entanglement, it would be impossible for some would-be eavesdropper to intercept and read the message without the recipient detecting such tampering.

This quantum cryptography was later demonstrated for light signals sent through the air or down optical fibres, and in 2007 the technique was used for secure transmission of the results of a Swiss election. Quantum cryptography has now been carried out for messages sent from China to Austria via signals bounced off a special quantum-enabled telecommunications satellite.