Skip to main content

Computing with Quantum Cats – John Gribbin ****

A new John Gribbin book is always a delight, and he is at his best when exploring the bizarre possibilities of quantum theory. If you aren’t familiar with his previous books on the subject, the title here might be worrying as it suggests some fiendish bio-electronic device where collections of unwilling cats are wired into a computer, but in fact it’s a follow on from earlier titles In Search of Schrödinger’s Cat and Schrödinger’s Kittens, where the relevance of the cats to the topic has become increasingly strained.
What we have here is an introduction to the wonderful world of quantum computers. Usefully, Gribbin leads us in through conventional computing, with workmanlike short biographies of Turing and von Neumann to help make the route to understanding what is going on in devices we use every day, but of which we have little comprehension, much clearer. It’s good to have a computing history that fully takes into account the British contribution, often sidelined by US work, in part because of the way Churchill unfortunately insisted that most of the UK wartime work be destroyed.
The second section of the book takes us into quantum theory, using Richard Feynman and John Bell as the key biographies, while the third concentrates on quantum computing, leading on the perhaps rather less obviously central character of David Deutsch and taking us through some of the many mechanisms for building a quantum computer that are currently being worked on.
Overall this works very well, and we get a powerful insight into the capabilities of this remarkable technology and the huge challenges that are faced in making it work reliably. To get any idea of how quantum computers work it is necessary to give a good background in quantum theory itself, and this is something that Gribbin can do with one hand tied behind his back. It is indicative of the strange nature of quantum theory that when writing on the subject, I take a very different line on some aspects – notably the many worlds interpretation – and yet both views are currently unassailable. You might even say superposed.
If I have any criticism it is that some areas are brushed over just a little too lightly – this isn’t the book to really get a total low-down on quantum physics as it isn’t its central topic. This means that there are a few places were Gribbin effectively says ‘this happens, but you don’t need to understand it.’ The only specific topic I do think could have been handled better is the very important concept of decoherence, which (unless I missed it) is introduced without ever explaining what it means. Certainly in the first reference to it in the index it is used as if it is obvious what it’s about. Yet in reality it is a subtle concept that is hugely important to the quantum computing business. I really wish there had been a few pages putting this straight.
Overall, without doubt the best book I’ve read to provide the general reader with an introduction to quantum computers, and given their potential importance in the future, that has to make it a brilliant addition to any popular science enthusiast’s shelf.

Hardback 

Kindle 
Using these links earns us commission at no cost to you
Review by Brian Clegg

Comments

Popular posts from this blog

Philip Ball - How Life Works Interview

Philip Ball is one of the most versatile science writers operating today, covering topics from colour and music to modern myths and the new biology. He is also a broadcaster, and was an editor at Nature for more than twenty years. He writes regularly in the scientific and popular media and has written many books on the interactions of the sciences, the arts, and wider culture, including Bright Earth: The Invention of Colour, The Music Instinct, and Curiosity: How Science Became Interested in Everything. His book Critical Mass won the 2005 Aventis Prize for Science Books. Ball is also a presenter of Science Stories, the BBC Radio 4 series on the history of science. He trained as a chemist at the University of Oxford and as a physicist at the University of Bristol. He is also the author of The Modern Myths. He lives in London. His latest title is How Life Works . Your book is about the ’new biology’ - how new is ’new’? Great question – because there might be some dispute about that! Many

The Naked Sun (SF) - Isaac Asimov ****

In my read through of all six of Isaac Asimov's robot books, I'm on the fourth, from 1956 - the second novel featuring New York detective Elijah Baley. Again I'm struck by how much better his book writing is than that in the early robot stories. Here, Baley, who has spent his life in the confines of the walled-in city is sent to the Spacer planet of Solaria to deal with a murder, on a mission with political overtones. Asimov gives us a really interesting alternative future society where a whole planet is divided between just 20,000 people, living in vast palace-like structures, supported by hundreds of robots each.  The only in-person contact between them is with a spouse (and only to get the distasteful matter of children out of the way) or a doctor. Otherwise all contact is by remote viewing. This society is nicely thought through - while in practice it's hard to imagine humans getting to the stage of finding personal contact with others disgusting, it's an intere

The Blind Spot - Adam Frank, Marcelo Gleiser and Evan Thompson ****

This is a curate's egg - sections are gripping, others rather dull. Overall the writing could be better... but the central message is fascinating and the book gets four stars despite everything because of this. That central message is that, as the subtitle says, science can't ignore human experience. This is not a cry for 'my truth'. The concept comes from scientists and philosophers of science. Instead it refers to the way that it is very easy to make a handful of mistakes about what we are doing with science, as a result of which most people (including many scientists) totally misunderstand the process and the implications. At the heart of this is confusing mathematical models with reality. It's all too easy when a mathematical model matches observation well to think of that model and its related concepts as factual. What the authors describe as 'the blind spot' is a combination of a number of such errors. These include what the authors call 'the bifur