2008-02-02 How quantum devices work.

"Beginners Guide" is about the relevance of quantum physics to everyday technology: semiconductors and transistors; energy sources and greenhouse gases; some not-so-everyday phenomena like superconductivity and SQUIDS; even the cutting edge stuff of quantum computing and quantum encryption. All are explained in terms of a few precisely stated properties of matter at the atomic scale or smaller. The weirdness of wave-particle duality and indeterminacy become accessible with minimal recourse to mathematics.

In successive chapters an insight is given into how materials acquire their large-scale chemical, physical and electrical properties by reason of what is going on at the level of electron, photon or atom. The way these particles are able to act with a concerted weirdness then seems just as reasonable as their bizarre individual behaviour.

The maths would be even easier to follow if more care had been taken with proofreading. Errors are confined mostly to the panels of mathematical details (where parameters annoyingly come and go like quantum particles) but there are also some in the main text.

Historical background is sketchy. We read: "James Clerk Maxwell . . . around 1860 showed the aether postulate was unnecessary". Arguably, it was he who started this entire goose chase; Michelson and Morley were still on the trail in 1887 and famously drew a blank; a kludge was proposed in 1892 by Lorentz; Einstein cleared things up a bit in 1905 - but the hunt ran and ran.

A brief analysis of how quantum indeterminacy might actually come about is presented in a well-argued short chapter at the end. If this stimulates further interest, then get the excellent companion volume Quantum Physics - Illusion or Reality. Both books are rewarding reads.