Monday, 2 August 2010

'Leaping into the history of quantum theory'

A review from the Providence journal in the US:

'Something deeply hidden had to be behind things,” Albert Einstein thought as a child, thereby expressing the human need and compulsion to see through, behind and beyond the world that we inhabit in order to discover religious truths, scientific laws or cosmic visions.

In this clearly written and understandable analysis of quantum theory, the major discovery of 20th-century physics, Manjit Kumar, who has degrees in both philosophy and physics and is the author of “Science and the Retreat from Reason,” tackles an epic task and interweaves his chronological saga with biographies and backgrounds of all the major physicists who were involved — from Einstein, the “Pope,” to Niels Bohr, the Danish “King,” from Paul Dirac’s silences to Wolfgang Pauli’s sarcastic asides, from French princes to German professors, laboratories and “thought experiments” to the quantum leaps of physicists from the major universities and institutes in Munich, Gottingen, Copenhagen and Berlin.

When Max Planck in 1900 discovered the quantum, “the indivisible packet of energy,” as well as matter, he was unaware that he had destroyed centuries of Newton’s mechanical, deterministic and materialistic vision of the cosmos, undermining notions of gravity and clearly defined orbits.

In 1905, Einstein discovered that light was a particle, made up of quanta, and thus upended the century-long belief in light as a wave, though Newton had thought in terms of particles of light as well. Einstein went on to conjure up relativity, in which matter and energy, forever separate before 1905, became interchangeable, limited only, as in all things, by the speed of light.

Kumar makes the fifth Solvay conference in Brussels in October 1927 the centerpiece of this fascinating, intriguing tale of speculations made and shattered, friendships formed and strained, lavish correspondences that exploded and collapsed, and the heady rush to publish papers in leading journals in order to stake out the latest possible theory and reveal yourself on the cutting edge of the new, confounding vision of the subatomic world.

Politics also intervenes, with the Nazis condemning “Jewish physics” and the flight into exile of many German scientists. At that conference, Einstein and Bohr squared off in terms of what all the quantum mechanics, matrices and wave equations meant, wrestling with one another’s theories in terms not of animosity but of camaraderie.

Bohr had decided that everything was both a particle and a wave — the central conundrum of quantum theory — mutually exclusive but necessary. However, one could measure the radioactive traces of electrons and photons on photographic screens only as particles or waves, never simultaneously. Because he believed that the act of measurement always interferes with and disturbs what we are seeing, we can only see snapshots of the quantum realm. “An unobserved electron does not exist,” he declared. Uncertainty, discontinuity, chance and accident govern all things. Only statistical probabilities worked.
Einstein, on the other hand, believed that the subatomic realm exists independent of human observation. Quantum theory had proved itself, but it was incomplete, and that possibility of incompleteness has dominated the study of physics ever since. How does measurement interfere? Is there a border between the quantum realm and our own?

Kumar has done a splendid job of explaining complex theories and describing the people involved with discovering them, mired in cultural and historical upheavals that haunted all of them. This is a necessary, mesmerizing and meticulous volume.'

'Pulsar' on Quantum

'Pulsar' from Belgium on the League of Reason site gave Quantum this stellar endorsement:

‘I just finished "Quantum: Einstein, Bohr and the Great Debate About the Nature of Reality", by Manjit Kumar.

It's one of the best pop-science books I've ever read, and I cannot recommend it highly enough. The book describes the history of quantum mechanics, notably the first three decades of the 20th century, and all the major characters involved - physics, biographic info and European history are intertwined into a real page-turner. It's absolutely fascinating to see how Planck, Einstein, Bohr, Rutherford, De Broglie, Born, Pauli, Dirac, Heisenberg and Schrodinger constantly inspired each other in their obsession to understand atoms and radiation.

The central part is the Great Debate between Einstein and Bohr about the Copenhagen Interpretation of QM, the relation between physics and reality, and Bell's theorem to test the completeness of the theory. I must say, this book shows Einstein's views of QM in a way I knew little of. Often, Einstein is depicted as a relic who couldn't keep up with the latest physics and never really 'got' QM. But in reality he knew damn well what he was doing (and he convinced Schrodinger, who came up with his cat thought experiment). The standard interpretation of Bohr has dominated the teaching of QM ever since, but this book asks the question whether this domination is really justified. It might be time for a new revolution in physics...

A must-read!’

Book addict on Quantum

'Addicted to books' blogger Tracy had this to say about Quantum:

'This book is a gem, a history of quantum mechanics, not just about Einstein and Bohr, but about those other giants of physics and their discoveries - Planck's original accidental discovery of the quantum, Rutherford's discovery of the atomic nucleus, de Broglie's wave-particle duality, Pauli's exclusion principle, Heisenberg's uncertaintly principle, and Schrödinger's wave equation (and infamous cat). More than this, Kumar's book brings those Nobel prize-winning scientists to life - Heisenberg's rivalry with Schrödinger, Pauli, the sharp-witted Austrian who rarely surfaced before noon, de Broglie, both a German prince and a French duke and the quiet Englishman Dirac, bullied by his overbearing father.

Having brought you up to speed on the nature of quantum mechanics, lucidly explaining both the experimental evidence and the thought experiments beloved of Einstein, the author then hits you with the real argument, the interpretation of quantum mechanics: What does it really mean? What is the nature of reality? In the 'observer-independent reality, quantum theory is incomplete ' corner was Einstein, whereas Bohr and the majority of quantum physicists at the time were very much in the 'probablistic, observer-dependent reality' corner - Einstein's famous argument that 'God does not play dice with the Universe' countered by Bohr's response of 'But still, it cannot be for us to tell God, how he is to run the world.' And still the debate continues.

Manjit Kumar's book explains the science and the arguments beautifully-clearly and fairly. Highly recommended to anyone who likes science history and essential reading for anyone who is studying any kind of science. The kind of book that really does make you feel slightly more intelligent after you've read it, for a few weeks, anyway, until you forget Pauli's exclusion principle (no two electrons in an atom can occupy the same quantum state), de Broglie's equation linking wavelength and momentum gradually fades, Planck's constant, h, draws a blank and all you're left remembering is Schrödinger's cat, his famous thought experiment about a cat in a box, whose fate is determined by random radioactive decay of an atom.'

Lessons for today from the Golden Age of Physics

Norman Lewis posted this insightful piece at which I'm taking the liberity of reprinting here:

The call this week by Lord Browne, the former BP chief executive, for a sweeping review of the UK’s £4bn-a-year science budget to emphasise projects with the potential to bring short-term industrial benefits, has sparked a fury amongst scientists. (See ‘Common room clashes with boardroom on science budget’, Financial Times. This is precisely what we warned against in the Big Potatoes Manifesto where we argue in principle 4 ‘For Useless Research’ that research remains the bedrock upon which the flow of innovation ultimately depends – a bedrock that is increasingly being questioned and undermined in our short-termist recessionary times.

Lord Browne’s instrumentalism certainly makes re-stressing this point timely and urgent. But the correctness of this fundamental research proposition was forcibly driven home to me during my recent holiday when I had the luxury and sheer delight of reading Manjit Kumar’s tour de force Quantum: Einstein, Bohr and the Great Debate About the Nature of Reality .

This is an absolute must for all those supporters of Big Potatoes. It describes in a remarkably entertaining and accessible fashion, the history of science’s fundamental revolution – quantum physics and mechanics – and the remarkable intellectual battle between Albert Einstein and Niels Bohr and other brilliant young scientists who were at the heart of this inspiring story.

More importantly, it reveals some critical insights into the processes and interactions that led to a scientific revolution which gave rise to the innovations we now take for granted: the transistor, the computer, the World Wide Web, the communications revolution.

Kumar shows that when these great physicists formulated quantum mechanics from 1900 to 1930, they were trying to understand the fundamental laws of the universe, not invent something of great economic importance. Their quest was the sheer beauty of solving some of the most baffling and abstract theoretical questions. The implications of their quest were so far-reaching it impacted almost everything, transforming sister disciplines like chemistry, for example. Today, all chemists and material scientists are trained extensively in quantum mechanics. Biologists like Francis Crick, who won the 1962 Nobel Prize in Medicine for the discovery of DNA, realized many years ago that the laws of physics and quantum mechanics ultimately govern even biology.

Quantum mechanics is necessary to engineer solid-state devices such as transistors, which are the building blocks of electronics and computers. Understanding semiconductors (the building blocks of transistors), or any material cannot be fully grasped with classical physics alone (i.e. physics known before the discoveries of quantum mechanics and relativity). Without quantum mechanics, the “information age” (and much of modern science) would not exist today. The inventions of the computer, the transistor, the World Wide Web and the laser used in fibre optics, (the basis for a global telecommunications industry) owe their existence to quantum mechanics and are worth trillions of dollars.

But to stress this point again, these were unexpected outcomes. The pursuit was science, the quest for purity and the beauty of an unassailable proof – and a closer approximation of reality.

There were three things about the book that really caught my attention, which are so germane to the debate we have started with the Big Potatoes Manifesto:

Kumar relates the story about Max Planck, the father of Quantum who at the age of sixteen enrolled at Munich University to study physics because of his burgeoning desire to understand the working of nature. Planck spent three years at Munich which were to have a big impact on him, mainly because he was advised to give up physics as ‘it is hardly worth studying physics anymore’ because there was nothing important left to discover. Planck went on to become the father of quantum mechanics because, as he discovered, there was certainly a lot more to discover about how the world works. Planck reacted against the narrowness and conservatism of his peers. He defied the attitude, which we seem to accept today, that mankind had somehow reached the limits to knowledge. Instead his openness and willingness to question existing orthodoxy unleashed a scientific revolution, the creation of new knowledge and ultimately, the development of remarkable innovations that changed life in the 20th century.

The second striking point Kumar brings out in his examination of the interaction of this extraordinary group of scientists was their willingness to engage each other as professionals in a common quest for truth. First, what united them was a belief in objective truth. Second, that despite different opinions (and often bitterly at odds) they were nevertheless united as pioneers committed to something greater than themselves.

This is illustrated by the example of Max Planck’s endorsement of Einstein for membership of the Prussian Academy of Sciences in 1913 despite fundamentally disagreeing with his position on light-quanta. Planck’s proposal contained the following paragraph: ‘In sum, it can be said that among the important problems, which are so abundant in modern physics, there is hardly one in which Einstein did not take a position in a remarkable manner. That he might sometimes have overshot the target in his speculations, as for example in his light-quantum hypothesis, should not be counted against him too much. Because without taking a risk from time to time it is impossible, even in the most exact natural sciences, to introduce real innovations’ (p52)

Not only do we see a remarkable willingness to recommend a fellow scientist despite disagreeing with him but the clear connection between disagreements and risk as critical to scientific advance.

What a stark contrast with today where contestation is regarded as a religious infraction against ‘truth’ (as in the ‘Climategate’ debacle) and where risk is consciously prevented by concentration on what we already know or what Lord Browne thinks can be safely developed. Planck reveals what science is really about in contrast with today’s instrumentalism and manufacture.

The third and final striking point in the book is the nobility of the young scientists involved in this rich period of scientific discovery. For them, as in the example of Ernest Rutherford, exploiting their research for financial gain was seen as a distraction from the really important goal of making a scientific reputation for themselves. Rutherford who had started working on the detection of ‘wireless’ waves (radio waves) chose instead to pursue his academic passion (in contrast to others working in this field like the Italian Guglielmo Marconi who amassed a fortune).

This is not to suggest that exploiting scientific discoveries were wrong or that the people who did were somehow flawed. Far from it. It highlights how the pursuit of science requires those types of individuals who regard it as a noble calling and are given the freedom to pursue it regardless of measurable outcomes (as we would have it in today’s crude management-speak). Kumar reveals how the young men at the centre of the quantum revolution were driven not only by their own self- belief (and no doubt, huge egos), but also by the pursuit of something greater than material wealth – a belief in scientific and human progress.

Of course that is precisely what is being questioned today, which is why the media concentrates its attention on the exploiters of science rather that present-day pioneers. So the founders of Google are feted for creating Google whereas in the past we would be looking for the scientific contribution they might have made towards humanity’s body of knowledge. Today we celebrate exploitation rather than the wonder of science underpinning these achievements.

The question this raises is how we will ever create a culture that places greater value in the pursuit of knowledge rather than on its results?

As the world discovered through Max Planck, everything had not been explained. Kumar’s book is a great reminder that there is no such thing as natural limits and that the worst dimension of a culture of limits is that it constrains the thing we have an abundance – human ingenuity, perseverance and the noble ability to rise above petty egos, jealousies and parochialism to benefit humanity as a whole.

Kumar’s book is definitely Big Potatoes and should be read widely.

Born with Quantum history in the family

Carey Born, the granddaughter of the Max Born, the great quantum physicist who was instrumental in the development of matrix mechanics (he even taught Heisenberg what a matrix was) and put forward the probabilistic interpretation of Schrodinger's wave function (for which he was awarded the Nobel Prize) wrote this on

'Manjit Kumar has produced a brilliant, insightful account of the quantum story. Through a compelling narrative he interweaves the ideas, events and personalities involved in the paradoxical quest for the truth about uncertainty. The book is a fascinating read about this tumultuous and revolutionary period in the history of science. Highly recommended'.

Another reader's view of Quantum

'A brilliant read', says Steve Carleysmith on

'I found this a fascinating read. If you are interested in how science works and the power of personalities, you will love this book. Using really well researched personal details of the lives of the key figures, Kumar shows how quantum science developed and led to the scientific and philosophical conflict between Bohr and Einstein - a debate that continues to this day. What is real and what is only observed? Kumar blends biography and quantum theory, covering probably the most exciting period in the development of science and thought.'

'A book that is very difficult to close... maybe it's in a state that is both open and closed until you look at it, who knows?'

It was the the title of this review by C.A. Whitfield on that caught my eye. He or she writes:

'This has to be one of the most gripping non-fiction books I have ever read! It reads like a well-organised narrative and there is rarely a dull moment in the entire book, although the author did have plenty to work with. As well as the emergence of this controversial 'quantum physics' the scientists had to compete with the outbreak of two world wars, it was not an easy time to be a theoretical physicist.

The chapters each focus on a different player in the quantum debate so that the reader gets a taste of the characters' backgrounds and their individual work that all led to the great breakthroughs that were made. This means that by the point in the story when all the characters are starting to meet and debate the implications of quantum mechanics, the reader finds they know their personalities and are compelled to find out who comes out on top.

Any physics that is mentioned in the book is explained thoroughly and generally only goes into as much detail as is necessary for the reader to understand the debate. This can get slightly tedious at times for anyone with a background in physics but it does mean that the book is suitable for anyone.

Overall, it is a fascinating and compelling read that find an exciting balance of scientific content, concerning what still is one of the most mysterious areas of physics, and the personal experience of the people involved.'

Quantum in Canada

Here's a review by Dr Stefan Miesbach on Amazon Canada:

'Manjit Kumar's "Quantum" is an absolute page turner. I could hardly put it away and wanted to read it all over again once I came to the end. There is not a lot of new content which cannot be found in biographies or other expositions of the quantum struggle, which ended with Copenhagen. What makes this book unique is a high-pace narrative style pulling the reader from one chapter with one fundamental discovery into the next combined with an almost uncanny ability of the author to unfold most complex physical and philosophical concepts at that same high pace. The narrative also makes the discussions, tensions and emotions so vivid that one feels compelled to jump right into the scenes to hear the debates first hand.'

Reader's review from 3

'Quantum of Delight' wrote Unfallen. And then went on write:
'A masterful balance of theory and history, Quantum is an engaging dip into one of the most fascinating streams of modern scientific discovery. The book includes simple, carefully calibrated explanations of the most important theories but does not get bogged down by them. The real story here is the colorful pioneers who explore the mind-boggling terrain that is the quantum world. The author fills his account with insightful portraits, revealing encounters, and one or two hilarious anecdotes which both humanize the major players and illuminate their astonishing genius. His style is accessible but never fritters. In fact, I think this material could be adapted for a marvelous course by "The Teaching Company." I think I'll tell them about it.'

Reader's review from 2

'A lot has been written about the Bohr-Einstein debate so when I first saw this book I did not buy it because I was skeptical about what more could be said. On reading other reviews I decided it might be worthwhile', said J Alia.

'Many scientists I've met are still passionate about the implications of quantum mechanics, Einstein's criticisms of the theory and Bohr's responses to those criticisms. Many scientists who are not outwardly enthusiastic about the debate and history seem to have approaches toward science that are influenced by it. (just my opinion). In any case, the subject of this book is fascinating.

Of the books I have read about this topic this one may be the best read.'