Customer Reviews

Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality

5 star:		(46)
4 star:		(5)
3 star:		(2)
2 star:		(1)
1 star:		(1)

 

 

The development of quantum physics through the 20th century is one of the great adventures of science, and here at last is a book aimed at the layperson which clearly explains its key concepts, while situating the scientific development in its broader setting. The result is a challenging and enthralling read.

Quantum is appropriately sub-titled, Einstein, Bohr and the Great Debate about the Nature of Reality. The long theoretical duel between these two giants of modern physics is a recurring theme of the book, but the story starts before them with the build-up to the discovery of Planck's constant at the turn of the century, and continues beyond their deaths (in 1955 and 1962 respectively) to take in Bell's Theorem and Everett's "many worlds" interpretation. Along the way we meet other great physicists such as Rutherford, Heisenberg, Pauli, Schrödinger, Dirac and Bohm.

One might suspect that a book of such scope would be in danger of being overcrowded with theories and theorists, yet Kumar rises to the challenge, displaying a novelist's sense of pacing allied with an impressive scientific clarity and succinctness. Clearly he has taken to heart the famous injunction attributed to Einstein to "make it as simple as possible, but no simpler!" He also strikes a judicious balance between scientific explanation and human context. This provided for me a welcome alternation between the physics and the lives of the physicists, with each stimulating an interest in the other.

What is so powerful and inspiring about this book is the way it conveys the passion for truth of those great pioneers. No doubt ego played its part as well, they would hardly have been human otherwise, but it is always secondary to the great quest to fathom the nature of sub-atomic reality. Characteristic of this passion is the anecdote of Bohr and Einstein on their first meeting in Copenhagen, straightaway so engrossed in debate that they repeatedly miss their bus-stop. Kumar evidently resonates to this passion, and conveys it vividly in his narrative. Here is an extract from his account of Bohr's first meeting with Schrödinger, one of Einstein's key allies in the great debate:

"After the exchange of pleasantries, battle began almost at once, and according to Heisenberg, `continued daily from early morning until late at night'... During one discussion Schrödinger called `the whole idea of quantum jumps a sheer fantasy'. `But it does not prove there are no quantum jumps,' Bohr countered. All it proved, he continued, was that `we cannot imagine them'. Emotions soon ran high... Schrödinger finally snapped. `If all this damned quantum jumping were really here to stay, I should be sorry I ever got involved with quantum theory.' `But the rest of us are extremely grateful that you did,' Bohr replied, `your wave mechanics has contributed so much to mathematical clarity and simplicity that it represents a gigantic advance over all previous forms of quantum mechanics.'

"After a few days of these relentless discussions, Schrödinger fell ill and took to his bed. Even as his wife did all she could to nurse their house-guest, Bohr sat on the edge of the bed and continued the argument. `But surely Schrödinger, you must see...' He did see, but only through the glasses he had long worn, and he was not about to change them for ones prescribed by Bohr."

This book is a brilliant and compelling account of the genesis of quantum physics, but it is more than that. In the midst of today's pervasive cynicism and disorientation, it is an inspiring reminder of what the human spirit is capable of when it devotes itself passionately to the highest aim, that of understanding the truth of our reality.

Kumar's book on the history of early twentieth century physics and atomic theory skips from page to page, fleshing out scientific expanations with vivid descriptions of the key protagonists. It is a real skill to make sophisticated scientific theories accessible to the lay person, but Kumar's use of metaphor helps bring the most intangible concepts to life. This is a modern classic, but more important, a really fun read.

The great Einstein-Bohr debate about physical reality is interesting not only to physicists, but also to great many readers interested in understanding the nature. This discussion between Bohr and Einstein over the interpretation of quantum theory began in 1927 at the fifth Solvay Conference. The debate over the ability of quantum theory to describe nature was fueled by many leading physicists of the time, some of whom directly contributed to the development of quantum physics, but later found themselves arguing against the theory they helped to create. Notable examples include Erwin Schrodinger, Paul Dirac, and Max Planck; the latter two did not actively participate in challenging the quantum reality. Bohr and Einstein spent many years intensely debating the nature of reality, and their discussions are known for very famous Einstein's comments such as; "God does not play dice,' or "God is slick, but he ain't mean," and Bohr's response was "don't bring God into this (discussion of quantum physics)." Bohr argued vigorously against both deterministic and realistic world, but Einstein was equally adamant to defend these two physical and philosophical concepts. Deterministic philosophy was spurred by Newtonian mechanics; if we know a system and its physical properties (size, color, or position) at one point in time, then at some point in future we can predict the system based on these physical properties. Bohr argued that complete knowledge of the present can result only in a description of what the future most probably will be like, but there is no such thing as certainty in quantum world. This thought is mystified by what is commonly called Copenhagen interpretation, and its strong proponents were Niels Bohr, Werner Heisenberg, and Max Born. Classical reality envisioned by Einstein was supported to a certain level by Schrödinger. Recent historical research shows that Paul Dirac had his own doubts about Copenhagen school of thought (1), and Max Planck, the founding father of quantum physics, lived until 1947 did not participate directly in Einstein-Bohr debate because of his own insecurities about quantum reality. When experimental test for Bell's inequality was conducted by Alain Aspect and others, many thought that Einstein was definitely wrong, but recent advances say, not so fast. Physicist Roger Penrose and many others believe that quantum physics is an incomplete theory (2). Few weeks ago when Large Hadron Collider (LHC) conducted test runs, Stephen Hawking expressed pessimism of finding Higgs Boson in LHC experiments by stating that "I think it will be much more exciting if we don't find the Higgs. That will show something is wrong, and we need to think again. I have a bet of 100 dollars that we won't find the Higgs." In a poll conducted in 1999 at Cambridge University, 55% of physicists polled for none of the existing quantum interpretations are right. This shows that not everything is settled in quantum physics.

History of quantum physics is the best example to understand how scientists work. Their collective efforts to understand the universe we live in through publications, conferences, discussions correspondence and collaborative efforts are essential to scientific advancement. The author describes these things well in the book, but he falls short in certain areas; his current work uses previously published works of Max Jammer (3), Jagdish Mehra and Helmut Rechenberg (4) as his few sources of information, but he could have researched a little more by talking to people who were directly associated with Einstein or Bohr. In a recent book by Louisa Gilder (5), after interviewing a colleague of Boris Podolsky, she reported that Rosen or Podolsky never asked Einstein for his permission when they published the classic Einstein, Podolsky and Rosen paper, 'Can Quantum Mechanical Description of Physical Reality Be Considered Complete." It is also stated elsewhere that Einstein never thought this was going to be a paper; the ideas came out during informal discussions (6). The author discusses the results of crucial experiments such as tests of Bell's theorem, and other work that may have lead to confusions or mistakes.

Many who are familiar with the history of quantum physics think that even though Einstein is unquestionably the best scientist mankind has ever seen but they also believe that he was grumpy old man who did not appreciate new and novel ideas in physics. This is certainly not true according to physicists who knew him. He helped Max Planck in the development of early ideas such as quantized energy levels in quantum physics. Einstein was not against new ideas such as the probabilistic or statistical interpretation of quantum mechanics, but the denial of an independent reality bothered him immensely. This lead to another famous quote from Einstein: "I think that a particle must have a separate reality independent of the measurements. That is an electron has spin, location and so forth even when it is not being measured. I like to think that the moon is there even if I am not looking at it." The author resurrects these ideals of Einstein hastily when he discusses experimental tests of Bell's theorem. He concludes that Einstein's doubts about the completeness of quantum mechanics are vindicated.

1. Alisa Bokulich, Paul Dirac and the Einstein-Bohr Debate. Perspectives on Science 2008, vol. 16, no. 1, pages 103-114.
2. Spirituality and the Nature of Reality - A discussion between Roger Penrose and T. D. Singh, Published by Bhaktivedanta Institute, 2007 (ISBN: 8190136976)
3. The conceptual development of quantum mechanics (International series in pure and applied physics)
4. The Historical Development of Quantum Theory. 7 book set. Vol.1, Parts 1 and 2. V.2, V.3, V.4, and V.5, Parts 1 and 2
5.The Age of Entanglement: When Quantum Physics Was Reborn
6. Schrodinger's Kittens and the Search for Reality: Solving the Quantum Mysteries Tag: Author of In Search of Schrod. Cat
7. Schrödinger: Life and Thought
8. Einstein, Bohr and the Quantum Dilemma: From Quantum Theory to Quantum Information
9. SPOOKY PHYSICS: A Brief Introduction to the Einstein-Bohr Debate (Neural Library)
10. When champions meet: Rethinking the Bohr-Einstein debate [An article from: Studies in History and Philosophy of Modern Physics]
11. Uncertainty: Einstein, Heisenberg, Bohr, and the Struggle for the Soul of Science

There are a number of very striking themes and trends in Quantum that other reviewers have not brought out, being dazzled, no doubt, by the swift pacing, tantalizing prose and cliffhanger hooks that Kumar employs so magnificently in Quantum.

First, as someone who has struggled to understand quantum mechanics when it is presented in textbooks as a whole system, I was delighted to find that physicists have the same problem. Even (if not especially) Albert Einstein. By taking us through the history of it, and enjoying the exhilaration of every incremental discovery, theory and step, I find I am really comfortable reading about it, and have no difficulty assimilating it. When you're along for the ride instead of the textbook, it makes a gigantic difference. Bravo, Kumar.

Second, it became painfully obvious that physics is far more philosophy than science. I felt like the arguments came from my Logic 101 class. Socrates would have enjoyed crossing swords with Bohr. The arguments of the scientists were really basic, philosophical differences of opinion, not the least bit esoteric or idiosyncratic. It seems that medicine is not the only "science" where they tell you to get a second opinion. That was a revelation, and it made physics all that more human.

Third, Quantum confirms a lifelong suspicion that this was and is a young man's game. It seems that every time things started to get stale, some precocious 26 year old student would come along with a new portion of a theory, and rock the establishment. And then live off that discovery for the rest of his life - winning the Nobel Prize (as almost every one of them eventually did), getting professorships - but never shaking the tree again. In music we would call them one hit wonders. Einstein was about the only one with two hits - brainstorms in 1905 and 1916 - but then, even he couldn't fathom the totality of quantum physics and never made another major contribution to its progress. By the age of 50 he was calling himself an "old fool".

So in addition to all the praise heaped on Quantum for its superior exposition, I think it's a wonderful addition to the discussion of the human condition. Valuable on a number of levels.

What a great book.

Mr. Kumar's book is very good or a waste of money, depending on the sophistication of the reader, so please don't attach too much significance to the star rating.

If you don't know much about quantum mechanics and are looking for an easy to read popular account, I would give this at least 4 stars, maybe 5.

They say you should always read the (old) masters. But for popular accounts of QM this is a bad idea, because the early popular accounts are bedeviled with bad philosophy and misconceptions. Bohr believed in a particular philosophy called phenomenalism, related to positivism, which states that real object don't really exist in themselves, but only your perception is real, or your reaction to stimuli. The Copenhagen Interpretation of QM is imbued with this philosophy.

Because QM was very mysterious in the beginning, it was very easy to take this defeatist attitude, and the Copenhagen Interpretation, so called because Niels Bohr lived in that city, became a dogma which persisted for a long time.

There were a few independent spirits such as Einstein, with his EPR paradox and Schroedinger, with his cat, but independent thought in general was discouraged and even punished.

It didn't help matters that the usually clear thinking von Neumann made a logical error in his axiomatic description of QM that made it seem worse than it was.

So it's good to read a modern popular account that is free of these "ghosts."

So a modern popular account like Kumar's is a better book for the novice, because we have finally gotten over the Copenhagen disease, and Einstein's views look better and better.

On the other hand, for me the book was a waste of money. For the reader who wants to delve deeper into the exciting new "reality" research, there is first of all the easy book "Quantum Reality," and then the more advanced "Time's arrow and Archimeades Point," by Huw Price. It seems that the easiest way out of the paradoxes in QM is to allow a limited amount of backward causation at the micro level.

Manjit Kumar's book is a fascinating history of one of the most
fundamental areas of science.Just as the title says, it is a history
of the great debate about the nature of reality with Einstein and
Neils Bohr leading the opposing views. Quantum Mechanics has always
been a fascinating subject for me, mainly because I could never hope
to understand it enough, however much time I spent on it. This
brilliant work takes you through the history of the ideas behind
quantum mechanics from the late 19th century all the way till the
latter half of 20th century.
Manjit Kumar sets the stage slowly as he describes the contributions
of great scientists ranging from Rutherford, Max Planck, Einstein,
Bohr, de Broglie, Pauli, Heisenberg, Dirac and Schroedinger. Their
works are captured along with a short historical background to provide
the context. Then the stage is all set for the great question about
the nature of reality. Bohr and Heisenberg and many others insist that
there is no objective reality. Bohr says: 'There is no quantum world.
There is only an abstract quantum mechanical description.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."
On the other hand, Einstein insists on his belief in the existence of
a causal, observer-independent reality. He says: "What we call science
has the sole purpose of determining what is". Einstein and his
Princeton team produce an ingenious thought-experiment called EPR that
casts a major shadow on the Bohr-Heisenberg view called the
'Copenhagen Interpretation'. However, for all practical purposes, most
scientists by the mid-20th century accept the Copenhagen view and get
on with their science. Albert Einstein toiled till his death to find a
Unified Field theory from which he hoped to derive the laws of Quantum
Mechanics. But he wasn't successful.
The book brings out the essence of those exhilarating times in science
when great minds battle year after year on the nature of Reality
amidst two major world wars and the looming threats of fascism and
communism. In spite of their battles for decades, both Bohr and
Einstein were such great human beings, having a great regard and
affection for one another. The other giants like de Broglie, Pauli,
Heisenberg and Schroedinger also show great respect and regard for
their opponents' views and keep egos and personalities out of the
equation.
Manjit Kumar's narrative brings out all these essential human
qualities quite vividly. He has a great ability to write. The book is
lucid and delightfully accessible in spite of the difficult subject
matter. I enjoyed reading it immensely. In many ways, it is like a
thriller, as you keep looking for the next thought experiment that
Einstein would come up with to counter Bohr only to find out how the
Copenhagen team overcomes each of these hurdles. I would recommend it
strongly to anyone interested in popular science in general and
Quantum Mechanics in particular.

Of all the hundreds of books I have read, "Quantum" is truly the best! The history of the quantum era is captured in wonderfully rich detail and all of quantum mechanics' historical, personal, and scientific achievements come to life under the skillful writing of Manjit Kumar.
I was introduced to this book by a friend who has the audio version. Right from the beginning of my listening adventure, I knew I had to obtain the book itself....which I did....from Amazon.com. I wanted the best, so I ordered the hardcover edition. I plan on reading this again, to my kids.
You do not have to be interested in quantum mechanics or physics to enjoy this book....it has all the elements of a historical masterpiece. I can find no fault in any of it.
Like a great work of art, "Quantum" will sweep you off your feet. Immediately immersing you in a world where few have been, and fewer still travel, Manjit brings it home for all of us.
Interwoven in the historical details of quantum physics' explosive beginnings, lies the personalities of some of the greatest scientists this world has seen to date. And it's a rare book that is historical in nature, but reads like a best-selling novel. I am truly impressed.
After it arrived in the mail, I literally could not put "Quantum" down...until it was read from cover to cover....and I had already listened to the Audible version!
Needless to say, I recommend this book to anyone, regardless of what type of book you are drawn to, "Quantum" has it all.
Do yourself and your family a favor...buy the hardcover so it will last a lifetime...and without doubt, it will make a wonderful family heirloom. It would also make a great gift! -reviewed by Alan

My bookshelf holds many titles explicating quantum physics for the interested layman (I am a retired attorney), but Manjit Kumar's "Quantum" stands alone. Many of these books focus on the personalities of and personal/professional conflicts among those who made advances in the field over the course of more than a century and, as a result, the science can get lost in the human-interest forest. Others highlight the 'hard science' without historical context and the presentation gets lost in the weeds of 'quantum weirdness'.
Kumar's book is unique, in my reading experience, in the perfect balance it manages to strike. It is rich in details of the human side of the story but always in a way that illuminates the evolution of the science. As a result, the entire landscape becomes clearer, including several areas which had for me always remained somewhat opaque. I am thinking, in particular, of EPR, Bell's Theorem and their progeny. In addition, Kumar's presentation creates a space around the Copenhagen Interpretation within which critical thought can be applied (many of the books in this area taking some form of the Copenhagen Interpretation as axiomatic).
At ground level, quantum mechanics is a mathematics that works; practitioners can apply it as a tool without giving any thought to the higher-level questions it raises. One level up, one finds the subject matter of most of the 'quantum for laymen' books I have read -- explications of what is commonly termed 'quantum weirdness'...superposition and Schrodinger's Cat, particle/wave duality depending upon the experiment, entanglement and 'spooky action at a distance' etc etc. All very interesting and challenging.
Kumar's "Quantum" includes but goes beyond that level of inquiry to focus the reader on the philosophical question as to what quantum physics has to tell us, if anything, about the nature of reality -- what is 'real' prior to or independent of observation? Is the universe itself the product of wavefunction collapse? Is the concept of 'the' universe itself valid? And much more.
"Quantum" is, as a result, a singular achievement.

Manjit Kumar's book is a fascinating history of one of the most
fundamental areas of science.Just as the title says, it is a history
of the great debate about the nature of reality with Einstein and
Neils Bohr leading the opposing views. Quantum Mechanics has always
been a fascinating subject for me, mainly because I could never hope
to understand it enough, however much time I spent on it. This
brilliant work takes you through the history of the ideas behind
quantum mechanics from the late 19th century all the way till the
latter half of 20th century.
Manjit Kumar sets the stage slowly as he describes the contributions
of great scientists ranging from Rutherford, Max Planck, Einstein,
Bohr, de Broglie, Pauli, Heisenberg, Dirac and Schroedinger. Their
works are captured along with a short historical background to provide
the context. Then the stage is all set for the great question about
the nature of reality. Bohr and Heisenberg and many others insist that
there is no objective reality. Bohr says: 'There is no quantum world.
There is only an abstract quantum mechanical description.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."
On the other hand, Einstein insists on his belief in the existence of
a causal, observer-independent reality. He says: "What we call science
has the sole purpose of determining what is". Einstein and his
Princeton team produce an ingenious thought-experiment called EPR that
casts a major shadow on the Bohr-Heisenberg view called the
'Copenhagen Interpretation'. However, for all practical purposes, most
scientists by the mid-20th century accept the Copenhagen view and get
on with their science. Albert Einstein toiled till his death to find a
Unified Field theory from which he hoped to derive the laws of Quantum
Mechanics. But he wasn't successful.
The book brings out the essence of those exhilarating times in science
when great minds battle year after year on the nature of Reality
amidst two major world wars and the looming threats of fascism and
communism. In spite of their battles for decades, both Bohr and
Einstein were such great human beings, having a great regard and
affection for one another. The other giants like de Broglie, Pauli,
Heisenberg and Schroedinger also show great respect and regard for
their opponents' views and keep egos and personalities out of the
equation.
Manjit Kumar's narrative brings out all these essential human
qualities quite vividly. He has a great ability to write. The book is
lucid and delightfully accessible in spite of the difficult subject
matter. I enjoyed reading it immensely. In many ways, it is like a
thriller, as you keep looking for the next thought experiment that
Einstein would come up with to counter Bohr only to find out how the
Copenhagen team overcomes each of these hurdles. I would recommend it
strongly to anyone interested in popular science in general and
Quantum Mechanics in particular.

I would encourage anyone interested in this subject to read this book. That said, it's important to understand what this book covers and at what level; coming to this book with a background in physics, and having read other books on the interpretation of quantum mechanics, I didn't find any further insights into the subject here. The book is generally well-written, albeit with some purple prose here and there that I found a bit annoying. It is most appropriate for a reader with a non-technical background who's willing to stretch; to anyone who's taken a course in elementary modern physics, all of the mathematical content will be very familiar. The summary historical lead-up to the main subject is masterful - there are a lot of people, places, developments and concepts to introduce, and the author does the best job of this that I've ever encountered. What I found unique was the chronology of the arguments, liberally illustrated with direct quotes from the participants - while I've read a number of meatier books on the subject, none provided the historical perspective here, which leads to an appreciation of the depth of thought over decades that's led to our current (lack of) understanding.

For those who have finished this book and are looking for more, a couple of suggestions: Uncertainty: Einstein, Heisenberg, Bohr, and the Struggle for the Soul of Science, which addresses the same subject in a different way - more from the perspective of the ideas than the chronology - and which I would say that I found to be more compelling; Beyond Measure: Modern Physics, Philosophy, and the Meaning of Quantum Theory, which is much meatier and satisfying in addressing the meaning of quantum theory, but which requires one to go further with the concepts/mathematics.