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
Labels:

Comments

Post a Comment

Popular posts from this blog

The Infinite Book – John D. Barrow ****

Authors are often asked to review books on a topic they’ve written on themselves. The reasoning is sensible – they ought to know something about the subject – but there’s always that uneasy suspicion that there’s going to be a bit of bias creeping in. So I think it’s only fair to admit up front that I have written a book on infinity (of which more later). Infinity is a wonderful subject, because it’s intimately mind-bending (if the combination sounds paradoxical, that’s what infinity is all about) and gives you the chance to pull in all sorts of different concepts and assocations along the way, something Barrow does with great gusto. There’s a surprisingly large amount of coverage here for God, and for the universe, and the book jumps around from Aristotle to Hilbert’s Infinite Hotel (explained at great length), from the paradoxes of infinite sets to the paradoxes of time travel. Overall it’s an enjoyable journey that gives plenty of opportunity to be amazed and surprised. The...
Post a Comment
Read more

Battle of the Big Bang - Niayesh Afshordi and Phil Harper *****

It's popular science Jim, but not as we know it. There have been plenty of popular science books about the big bang and the origins of the universe (including my own Before the Big Bang ) but this is unique. In part this is because it's bang up to date (so to speak), but more so because rather than present the theories in an approachable fashion, the book dives into the (sometimes extremely heated) disputed debates between theoreticians. It's still popular science as there's no maths, but it gives a real insight into the alternative viewpoints and depth of feeling. We begin with a rapid dash through the history of cosmological ideas, passing rapidly through the steady state/big bang debate (though not covering Hoyle's modified steady state that dealt with the 'early universe' issues), then slow down as we get into the various possibilities that would emerge once inflation arrived on the scene (including, of course, the theories that do away with inflation). ...
Post a Comment
Read more

Adventures of a Computational Explorer - Stephen Wolfram ***

Stephen Wolfram, the man behind the scientist's mathematical tool of choice, Mathematica, plus a whole host of other software products, including the uncanny Wolfram Alpha knowledge engine, is undoubtedly a genius of the first order. In this book, we get an uncensored excursion into the mind of genius - which is, without doubt, a fascinating prospect. The book consists of a collection of essays and speeches that Wolfram has produced over the last ten to fifteen years, covering an eclectic range of topics. Like all such collections, the result is something that lacks the coherence of a book with a narrative that runs through it, inevitably introducing a degree of repetition and a mix of interesting and not-so-interesting topics - but there's likely to be something to catch the attention anyone who is into computing or mathematics. One of the most interesting pieces is the opening one, where Wolfram describes being a consultant on the SF movie Arrival. He seems to hav...
Post a Comment
Read more