I'm finally starting to understand Quantum Physics a little bit, thanks to Kumar's fascinating overview of its historical and theoretical developments. Parts were hard to follow, but I think a lot of that is because it's a hard topic, not because Kumar wasn't able to break it down. The last quarter was where it really started to (kind of) make sense for me. I empathise with Einstein - it seems like madness to accept there's no reality apart from observation. But I'm starting to get Bohr's point - that there can never be an objective observer or an unaffected observation, so it makes no sense to talk about an objective reality. It's a trick we use in thinking about the world, but it's still just a trick. The interesting implication of the Copenhagen interpretation of Quantum Mechanics is that there seems to be no way to posit a supernatural realm either. It can only be thought about as a trick, but ultimately unknowable, and irrational to seriously consider. I have more thoughts about QM, but they're still congealing. I think QM, rationality, and Relativity are all related.....

As a complete non-scientist (GCSE and A-Level Biology is all I have) I found this book very hard work but absolutely fascinating. I did have the advantage of two physicists in the family to explain various concepts to me - for example, I didn't know what a constant was, or a blackbody. Also, I found that occasionally there wasn't enough detail - he didn't explain how Bell came to his conclusion and I don't like just taking things on trust, so had to go and find out.

But on the whole, I found it quite entrancing. I enjoyed reading the history of quantum theory and seeing how it developed from a very simple concept and was gradually built on by different people until it became the madly complicated thing it is today. I have fallen in love with quantum physics!

I used to munch my way through any book I could find on Relativity, Quantum Mechanics or any similar topic.  I've been out of that for a few years, but recently I picked up Quantum, by Manjit Kumar.  Subtitled "Einstein, Borh and The Great Debate About The Nature of Reality", it's partly a book describing the "story" of Quantum Mechanics, and partly about how the theories relate to "reality".

I can't seem to finish many books these days, so any that drive me to finish them deserve a special mention just for that fact.  This is one such book.

Manjit writes in quite an engaging style, but isn't afraid to get down and dirty with a few equations and diagrams to help things along.  This book slowly introduces the people involved in the "story" of Quantum, referencing them only when they actually enter the story, rather than all at once.  The story then diverts to explore the new person and their contribution.

By doing this Manjit has managed to keep the story fairly linear, despite the number of people working on parts of the theory at the same time, and this helps keep the flow going quite nicely.

Even with Manjit's way of breaking things down into more easily understood explanations, a topic like this is never going to be "light reading", but even so I still read late into the night, when my brain was all but dead.

There are four things this book has, that I believe all books of this type should have:

1. A comprehensive "Notes" section.


2. A comprehensive Bibliography


3. A comprehensive glossary


4. A comprehensive index.

You may notice a common theme here.  I was surprised when I got to the end of the "story", and there was still about a sixth of the book left unread.  This is because it has all four of the above; with an emphasis on "comprehensive".

Really, if this topic interests you, this is a great book to read; and with all the appendices, it will point out even more places to look should you not have twisted your brain out your ear enough by the end of it.

what a rowdy bunch those physicists are....the debate still rages. But a good book following not only the science but the conversations, friendships and world events in the development of the quantum theory

A good history of the quantum theory, tracing the initial concept up through today’s attempts to unravel this seemingly self contradictory theory. Kumar does an excellent job of piecing it all together.

Here's an excerpt that I thought was particularly striking:
When Planck tried to explain to Hitler that expulsion of Jewish scientists would be harmful to German interests, Hitler replied “then we shall do without science for a few years.”

A good read but certain sections may be difficult for non-scientists like myself.

"When we know the present precisely, we can predict the future."

"It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature."

"The aspiration to truth is more precious than its assured possession."

Excelente libro de divulgación. Me hubiera gustado que profundizara en los temas mas recientes, que solo menciona: estudios de "entanglement", teletransportación y universos paralelos.