This book was pretty good. Seth Lloyd talks about Quantum Theory and Information Theory and how it combines to make the universe a Quantum Computer. It took longer than I thought to complete it, but it was still quite enjoyable. At first I didn't really know where he was going with his story, but eventually, he dives into it. ( )

Interesting book that logically was based on concrete fact, but wove lunacy in science to create a quantum computer based on quantum physics. Seemed to be a gigantic jump to go from entropy to entanglement. ( )

I really like Seth Lloyd. There are many extremely smart people today, but only few of them are able to explain and present certain theories so they are comprehensible to other people (especially in QM). So, in a way, Lloyd is like a modern Richard Feynman, also because he is witty, funny and easy to follow. Even though he deals with subjects that are way beyond our everyday experience, and even in that category, are very hard to conceptualize and understand, cause at a time they can be very counterintuitive, he still manages to connect them with things slightly closer to 'our world', so they become more presentable to people who are not so familiar with QM and information theory, and at the same time, offer a new perspective to people who are (and you can never have enough different perspectives of entropy, trust me). So this book is never boring even if you have previously encountered theory of universe as ultimate quantum computer, entropy explained through known and unknown qubits, connection of all of that with ToE...
In certain fields you can never find a middle ground between popular science literature and strictly scientific literature, and as someone who studied CS and will also be studying physics, lately I try to stay away from the first and focus on the second, but nonetheless, I really liked and enjoyed this book.
Also,I used to think I would be willing to give a kidney to be able to attend Lloyd's lectures @ MIT. I was wrong. Now I KNOW I would gladly give both of them. ( )

I really like Seth Lloyd. There are many extremely smart people today, but only few of them are able to explain and present certain theories so they are comprehensible to other people (especially in QM). So, in a way, Lloyd is like a modern Richard Feynman, also because he is witty, funny and easy to follow. Even though he deals with subjects that are way beyond our everyday experience, and even in that category, are very hard to conceptualize and understand, cause at a time they can be very counterintuitive, he still manages to connect them with things slightly closer to 'our world', so they become more presentable to people who are not so familiar with QM and information theory, and at the same time, offer a new perspective to people who are (and you can never have enough different perspectives of entropy, trust me). So this book is never boring even if you have previously encountered theory of universe as ultimate quantum computer, entropy explained through known and unknown qubits, connection of all of that with ToE...
In certain fields you can never find a middle ground between popular science literature and strictly scientific literature, and as someone who studied CS and will also be studying physics, lately I try to stay away from the first and focus on the second, but nonetheless, I really liked and enjoyed this book.
Also,I used to think I would be willing to give a kidney to be able to attend Lloyd's lectures @ MIT. I was wrong. Now I KNOW I would gladly give both of them. ( )

Interesting take on several fields - quantum mechanics, physics of the origin of the universe. Humor only added to book's lucidity. Worth a shot. ( )

One of the most readable books I've ever read. Extra credit to Seth Lloyd for making a mind-blowing topic such as Quantum Computation easier to grasp. ( )

I could only bear two or three chapters of this book, so this quasi-review might not be entirely fair.

The idea of a quantum computer was first broached by Richard Feynman and others in the 1980s. Lloyd gives us four reasons why building them is important:

* "The first is that we can ... We now possess lasers stable enough, fabrication techniques accurate enough, and electronics fast enough to perform computation at the atomic scale."
* "The second reason is that we have to -- at least if we want to keep building ever faster and more powerful computers." (This is followed by the customary, breathless retelling of Moore's law.)
* "The third reason to build quantum computers is that they allow us to understand the way in which the universe registers and processes information."
* "The final reason to build quantum computers is that it's fun."

Reasons one, two, and four are inane and unlikely to impress anyone but the most simple readers looking to be dazzled by science candy. His prose elsewhere is vapid and patronizing (which is why I put the book aside):

'I began the initial meeting of my MIT graduate course on information in the manner I begin all of my courses: "First," I said to the twenty-odd students, "you ask questions and I'll try to answer them. Second, if you don't ask questions, I'll ask questions. Third, if you don't answer my questions, I'll tell you something I think you ought to know. Any questions?"'

'I waited. No response.

'Something was wrong. Normally, MIT students are more than happy to try to stump the professor, particularly if the alternative is that the professor will try to stump them.'

I have a question: "How do I drop this course right now, you pompous fool?"

Lloyd's third reason gets to the thesis of his book: that the universe is a quantum computer. What is it computing? It's computing itself. Why? Well, because he says it is.

What Lloyd and others have shown is that they can model physical processes using information-processing metaphors. That's all well and good, but you can't leap from this metaphor to reality, as Lloyd does in this book. He wants us to believe that the universe really is a computer simply because it seems like one when you consider it that way. This is such a fundamental flaw in logic that I'm amazed this book got published.

I am probably being a bit harsh, but this book has gotten plenty of gushing reviews -- I think it can stand some harshness. I'm genuinely interested in learning the theory behind quantum computers, but I could do without all the grandiose, unsupported claims about life and the universe.

(Reviewed at Question Technology: http://www.questiontechnology.org/blog/2006/11/programming_the.html) ( )

Best current book on multiverse as a quantum computer (July 2007). ( )

Gives primacy to information theory, saying that the universe is one big quantum computer. Lloyd states some of his points on www.edge.org (under the heading "quantum monkeys").

Strangely lacking in argument, PtU contains a remedial-level overview of classical information theory, theory of computation and their quantum counterparts. It reads like an updated Pythagorean mysticism, or, less sympathetically, an orgy of computational fetishism. Lloyd is undeniably clever and convivial, but he has yet to make his case for universal computationalism. ( )