Wanted Dead Or Alive, Or Both

Home , Quantum tunnelling, Robert Anton Wilson

books & arts Wanted dead or alive, or both

The Quantum would look (don’t even try to imagine superpositions. On the way they introduce Divide: Why entangled states), it might be better to think complementarity, quantum tunnelling, Schrödinger’s Cat is of a dead and alive cat. This image is neither delayed‑choice experiments and quantum Either Dead or Alive particularly illuminating nor beautiful — teleportation. The physics behind these perhaps even disturbing for cat‑lovers — but quantum phenomena is explained in detail, By Christopher at least it feels tangible. from the workings of beam‑splitters and C. Gerry and Kimberley Writing about quantum mechanics in polarizers to more complex arrangements, M. Bruno scientifically accurate and yet intuitive terms such as the Mach–Zehnder and Hong– is hard. There are countless books on the Ou–Mandel interferometers. And although OXFORD UNIV. PRESS: subject, approaching it from every possible the authors touch on such varied topics, 2013. 197PP. $44.95. angle (for example, How to Teach Quantum they manage to maintain a steady flow Physics to your Dog, Quantum Theory and an overall sense of coherence (no Cannot Hurt You, Quantum: A Guide for the pun intended). uantum mechanics and quantum Perplexed and Who’s Afraid of Schrödinger’s All the discussions eventually lead to the information feature many eccentric Cat?), and it is amazing how many of central theme of The Quantum Divide: the Qcharacters, from the personality‑split these have cats on their covers. But The question of where to draw the line between photon to the omnipresent Alice and Quantum Divide: Why Schrödinger’s Cat is the quantum and classical worlds — if Bob. But without any doubt Schrödinger’s either Dead or Alive by Christopher C. Gerry this line does indeed exist. But Gerry and cat is the star: John Gribbin’s In Search and Kimberley M. Bruno is not just another Bruno explicitly take on this issue in the of Schrödinger’s Cat, with its sequel book on the list. It is an instructive and last two chapters, where they introduce Schrödinger’s Kittens and the Search for entertaining read — an excellent example macroscopic superposition states and the Reality, as well as science‑fiction novels of what ‘popular science for scientists’ decoherence‑induced transition to the such as Robert Anton Wilson’s Schrödinger’s should be. The Quantum Divide looks at key classical world. The final chapter gets more Cat Trilogy and so on. Few popular science concepts in quantum mechanics, illustrating metaphysical, tackling wilder notions, such books on quantum mechanics fail to them mainly with quantum optics as the many‑world interpretation of quantum mention “spooky action at a distance”, and experiments. The authors do not shy away mechanics or quantum consciousness — a even fewer omit the famous feline. Why is from maths and diagrams in explaining concept the readers are advised to be wary of. the cat so popular, and how did it become quantum phenomena such as superposition The Quantum Divide does not focus too iconic for quantum mechanics? It may and entanglement, and the experiments in much on the historical debates or mythical be because it is the only accessible visual which they show up. figures, giving due credit to contemporary representation of a field so full of abstract Gerry and Bruno take the reader research and the recent work of various and counter‑intuitive concepts. So to avoid from wave–particle duality, through experimental groups worldwide. Relevant the headache in trying to imagine how various quantum interference effects to references are given at the end of every simultaneously being a wave and particle quantum correlations and macroscopic chapter, and a quantum mechanics timeline is also included. Admittedly Gerry and ON OUR BOOKSHELF Bruno do go for a slightly cheesy title and Schrödinger’s Killer App: Race to Build the World’s indulge in a couple of geeky Star Trek First Quantum Computer references (unavoidable perhaps when By Jonathan P. Dowling dealing with teleportation), but they stick TAYLOR & FRANCIS: 2013. 453PP. £25.99. to a scientific yet light tone, with the right amount of anecdotal digressions. The A quantum code-breaker based on Shor’s factoring authors make an effort to avoid the usual algorithm could hack into even the securest parts of the quantum clichés and warn against the Internet, but not those things protected by quantum hyperbole and overstretched metaphors that cryptography. This book discusses the history, philosophy plague popular science writing. and progress of these state-of-the-art technologies. So does The Quantum Divide provide a more intuitive image of quantum Quantum Computing since Democritus mechanics? It does not, but this is neither By Scott Aaronson the authors’ intention nor the readers’ CAMBRIDGE UNIV. PRESS: 2013. 398PP. £24.99. expectation. Instead it gives a balanced and Democritus, the ‘father of modern science’, up‑to‑date account of fascinating quantum believed that atoms are the smallest constituents phenomena well beyond the double‑slit of matter. From these seeds of natural science experiment and Schrödinger’s cat paradox. followed ideas of logic and set theory, quantum It also advocates a more relaxed approach: computing and cryptography, and the meaning of “Quantum mechanics is weird, but not ❐ quantum mechanics. that weird.” REVIEWED BY IULIA GEORGESCU

NATURE PHYSICS | VOL 9 | MAY 2013 | www.nature.com/naturephysics 261