on 9 June 2009
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.
on 17 October 2008
This is fascinating book written as a narrative history of those scientists who contributed to the development of Quantum Theory - one of the most important challenges to orthodox thinking in the whole history of ideas.
The book does a very good job of establishing how classical physics of the 19th Century was seen as completed and except for a few minor details that needed tidying up, the consensus was that nothing really fundamental at a theoretical level was left to discover.
Kumar explores how this certainty that physics was done and dusted came to unravel and how an idea as counter intuitive as the quantum came to be accepted by most physicists.
This manner of exploring quantum theory through its historical development allows anyone with a basic grasp of science to understand why it is so revolutionary in its implications. At the centre of this story is the struggle between Albert Einstein and Niels Bohr about what our attitude to the reality should be.
Mixing historical narrative with the scientific ideas that were in contention brings quantum theory to a much broader audience of readers than is generally possible with this sort of material.
Part social history, part popular science as well as raising questions of a philosophical nature - this makes a cracking read and comes highly recommended.
Quantum mechanics is one of the most successful scientific theories ever made. But it is utterly non-intuitive for both the scientist and non-scientist alike.
In our everyday lives, things happen for a reason - you place a fork on a table and unless someone comes along and moves it, you can be certain that it will be still there the next day. Not so in the atomic world of quantum mechanics, an electron might be here... or it might be there ... or over there. In fact it could be anywhere in the universe at any given time. Quantum mechanics predicts this behaviour in the form of a probability wave function. And it works.
But is this the true nature of reality?
This is the theme of the book. We have two great scientists - Einstein and Niels Bohr who have a fundamental difference of opinion about the nature of reality.
From Einstein's' point of view, an electron has a real set of parameters such as location, velocity, spin and so on that is independent of an observer. He admits that quantum mechanics does a good job in predicting atomic behaviour but he is convinced the theory is not complete.
On the other hand, there is Niels Bohr's vision that an electron (or any microscopic entity) has no reality until an observer chooses to measure one of its parameters. He considers quantum mechanics to be complete with no further need for revision or modification.
This argument goes on for decades. The book takes the reader through the panoply of scientists who helped put quantum theory together from its beginnings around 1900 to today. Scientists such as Max Planck, Heisenberg, Dirac, Pauli, Oppenheimer, Von Neumann and many, many others are included.
The appeal of this book is that it brings humanity to the story of quantum mechanics. It shows the egos, the fears, the ambition of these extraordinary people as the story unfolds over decades.
If you want a pure explanation of quantum mechanics then you should look to a dry text book. But if you want the human context in which quantum mechanics evolved then I recommend you read this book.
on 22 June 2009
I have always been fascinated by how 'it' all fits together, but struggle to find the time to concentrate on dry theoretical texts. It was therefore with great delight that I found myself engrossed in Quantum on the tube, the bus and even occasionally the walk in between. Manjit Kumar's writing eases you effortlessly into the some of the most complex ideas in physics by juxtaposing the personal stories of the authors playing out through the 20th century with the theories themselves. Sufficient detail is provided to challenge all but the most experienced reader, and a comprehensive references list encourages further exploration for those who need to dig even deeper. While having to admit to only momentary glimpses of both the elusive beauty, and the black hole enveloped by quantum theory, I felt strangely comforted that even Einstein struggled to fully embrace such a world.
on 5 May 2010
I bought this book as a partial response to my 12 year old son's questions: "But what is infinity?" "How do we know that something is real?" He left me stumped and not a little challenged. I needed to get beyond Dr Who and thought the book might sate him.
Curiosity got the better of me and I was soon drawn into a world enriched by well drawn characters. Names that I had heard of but didn't know much about - Planck, Geiger, Rutherford, but others too, more familiar - like Hitler and GB Shaw. Others yet, I was glad to make the acquaintance of, like Wolfgang Pauli, described as a Buddha with a biting tongue. And John Stewart Bell of Belfast and Dr Bertelsmann's socks.
Quantum reads like an epic novel, with Einstein and Bohr cast as the main protagonists, with scientific truth taking the place of elusive love, an obscure object of their desires. Kumar's evocative and fluid prose describes the passion for ideas that is at the centre of the story. I didn't feel that I needed to understand it all, but understood what drove them.
But what of the science? Kumar does not shy away from the science but nor does he make it seem insurmountable to a lay reader. Boyle's law explained in a succinct paragraph is a model of elegant science writing.
There is much to commend Quantum apart from its opening up of this area of science. Kumar deftly weaves in the social and political context in which the characters are brought to life. A fundraising dinner for impoverished East European Jews hosted by Baron Rothschild in October 1930, is attended by Einstein. The septuagenarian GB Shaw toasts him: "Ptolemy made a universe which lasted 1,400 years. Newton, also, made a universe which lasted for 300 years. Einstein has made a universe, and I can't tell you how long that will last."
Einstein then speaks of moral traditions that have lasted a thousand years, and of service of life and of sacrifice. But, observes Kumar, that universe was ending `as the dark clouds of the coming Nazi storm gathered.' The previous month, the Nazis had increased their share of the vote by nearly eight times in a little over two years.
This then is a big book. A book about an icon and an iconoclast, encapsulated in one man, full of contradictions and all too human qualities. For Bohr, out of a theory came a philosophical position. For Einstein, a philosophy built on the foundations of a scientific theory was bound to be shaky.
Einstein says "..one assumes a real world existing independently from any act of perception. But this we do not know." And elsewhere "I have no better expression than `religious' for confidence in the rational nature of reality insofar as it is accessible to human reason. Wherever this feeling is absent, science degenerates into uninspired empiricism."
This reminded me a little of St Augustine's grappling with similar questions and of Pascal's Wager. There are probably a hundred other examples or more that can be cited and as many creation myths. But the ineffability of something has never stopped enquiry.
So what of quantum? Can I explain it to my son now? Well, as Kumar observes in his concluding paragraph, fifty years of `conscious brooding' had not brought Einstein any closer. I rest a little easier. In the end Einstein took solace in the words of Gotthold Lessing, a German philosopher, "The aspiration to truth is more precious than its assured possession."
For my part, I aspire to re-read this excellent book, and to yield possession of it to my son at a later date to see if he has any answers.
on 17 April 2009
My wife, Audrey, nominated this book as her Guardian Readers' Book of the Year, and wrote: As a fairly innumerate non-scientist I am perversely drawn to books about maths and science and usually abandon them with my ignorance intact. However, this was so well written that I now feel an ownership of the subject, smile knowingly when I hear the word 'quantum' and feel that I've more or less got particle physics sussed. QUANTUM transcends genre - it is historical, scientific, biographical, philosophical. It is a love story of great minds living and breathing their obsessions, rivalries and divided loyalties. It is as thrilling as a whodunnit - though more of a who-might-have, who-nearly-did and who, in the end hadn't quite dunnit. I'm exhilarated by the idea of thought experiments and now practise them daily in great hopes of finding the answer which has eluded them all so far. If only I knew what a matrix was!
Quantum is the unfinished story of the development of quantum mechanics. Unfinished? Yes, because the question which lies at the centre of the book is not yet resolved.
The story starts in late Victorian times when classic physics seems close to completion, to being able to explain the world fully. There seem to be just a few loose ends to be tied up. However, it is those few loose ends inside the atom, explaining the nature of the electron, being able to account for light behaving both like a particle and a wave etc which lead to the unravelling (at the atomic level) of previous world views.
Through the lives of Planck, Bohr, Einstein, Schroedinger, Heisenberg, Pauli, De Broglie and others we see how diferent strands of quantum theory were hotly contested and how it developed through analysis and synthesis.
One of the most exciting things about the book to me was the rigour and power of true scientific method. Quantum physics, despite being in some ways mind blowingly ethereal is subject to the most searching challenge and detailed research. We see two of the greatest minds of the 20th century, Einstein and Bohr sitting on opposite sides of the dispute, deploying their most powerful destructive intellectual weapons in order to test the veracity of each others ideas. If ever you doudt bthe superiority of genuine science over pseudo Science (are you listening Charles Windsor), read this book.
At the centre of the dispute is the Copenhagen interpretation of Quantum mechanics, at the heart of which is the assertion that reality is not indepedent of measurement. (it would take too long to explain more, but Schrodingers famous cat is involved). Through the book we see Bohr besting Einstein, but one feels that the author is sympathetic towards Einstein and there is a sense of relief at the end of the book that the door remains open for the father of relativity.
Also fascinating is that roughly half of the book is about the major advances in the development of quantum theory in the first three decades of the 20th Century and thereafter debate switched to the interpretation, in a nutshell, is it reality or just a convenient model describing the effect of an underlying reality.
This is no dry science book however, one gets to know the people involved and the story has as its setting the major events of 20th Century history, the first world war, the rise of the nazis, the development of the atomic bomb, and the cold war.
Kumar is a clear and engaging writer, and my only two criticims would be firstly that in his efforts to be comprehensoible he maybe keeps too far away from the hard science at times. Secondly the odd summarising passage, showing briefly what the current state of play was would be helpful.
Overall, definitely recommended, it's a book for everyone, not just the scientifically minded.
on 11 November 2008
I really enjoyed reading this book!
Excellent, interesting, story and subject.
I thought Kumar put it across in a very entertaining way, I did not get all of the minutia of the physics but that did not matter, I especially
enjoyed the suspense and his sense of humour. I also enjoyed the way
the story wove characters and events together, all the way through I was kept interested, he knows how to tell a story.
I got alot out of the information in the book; it filled in gaps for me in my knowledge about the subject as well as providing a really interesting back drop to the stuff I'd done at school. (I liked science till I got to the 6th Form.) The book worked on many different levels, as a history I became aware that there were quite often unintended results or consequences from experiments or ideas, some times others taking up
something someone else had accidently stumbled across and looking at it in a new way, I liked that, I found it thought provoking.
This gave me an interesting insight in to the whole unfolding
understanding of the science as it happened in time, this was one of the main areas focused on. Another aspect, the personalities
and how they interacted what they got up to I enjoyed hearing about
their interests and how they lived. 'Painting a picture' of the
scientists as people really worked for me.
on 28 April 2009
This is popular science history writing at its best, a satisfyingly readable and absorbing study of one of the most important scientific debates of the 20th century. Kumar is particularly strong on elucidating the tensions between Albert Einstein and Niels Bohr, tensions that both connected them as fellow theorists and held their ideas apart. The central divide in their physics, with Bohr very much at the centre of quantum theory and Einstein the skeptical outsider, put each of them either side of a philosophical line that runs through much of human thinking about the nature of mind and reality. Along with Dr Johnson kicking a tree stump to verify its existence, Einstein was in the objective-world-out-there camp: `What we call science has the sole purpose of determining what is.' Bohr perhaps had more in common with what certain schools of Buddhism call Mind Only: `It is wrong to think that the task of physics is to find out how nature is. Physics concerns only what we can say about nature.' Although the usefulness, elegance and continuing possibilities of quantum theory have meant that Bohr and his colleagues are celebrated as founding fathers, Kumar does a good job of rehabilitating Einstein as an incisive doubting Thomas who sought to show that quantum mechanics was an incomplete description of reality. It seems that Einstein's questions, once dismissed by the bulk of the scientific community, continue to resonate in current research into the paradoxical and mind-bending realms of sub-atomic phenomena.
While the Einstein-Bohr debate forms the beating heart of this book, as a non scientist I also very much enjoyed the social and biographical backgrounds to the scientific story that Kumar provides. Writing with pacy good humour he develops a fascinating picture of the often turbulent times through which these men (and, Marie Curie apart, they were mostly men) lived. There were just one or two points at which I would have preferred a little less of this in favour of more unpacking of the physics (us maths dummies need all the help we can get!) but then these are difficult ideas whichever way you look at them. As Kumar has remarked, if Bohr and Einstein et al. struggled with them it's no surprise that we should. Fortunately Kumar is a natural communicator of what has clearly been a project close to his heart. His eloquent fascination with the story of these ideas and of the men who formulated them make this book a highly engaging and stimulating read.
‘If you think you understand quantum mechanics, you don't understand quantum mechanics’, is a quote commonly attributed to the American Nobel prize winning physicist, Richard Feynman. But no matter who uttered this now famous statement, anyone who has ever had to try to learn quantum mechanics can probably identify with it.
In this brilliantly written exposition author, Manjit Kumar, succeeds in, at least, rendering the borders of the foreign country of the quantum open to access: that is, if the traveler has a corresponding smattering of knowledge to start with. Otherwise, it will remain almost impossibly esoteric. This is not for the complete lay person: it is packed, necessarily, with the language of physics. Without that it would not be possible to trace the significant milestones in the development of, what is seen by some as, the most successful theory in the history of science. Beginning, at the turn of the Nineteenth Century, with Max Plank, its reluctant originator, Quantum Theory sparked a revolution in the way we conceptualize the basic building blocks of the material world. And, even though few working in the field today, would argue seriously against this now widely accepted world view, few would also lay claim to understanding, completely, its full implications.
Along with each incremental development we learn about the extraordinary individuals who laid brick upon brick to build this sometimes creaking edifice, debatably the greatest of whom, Einstein and Bohr, argued ceaselessly, till the ends of their lives, regarding its merits or otherwise. Their ontological positions could not have been more polarized dealing, as they were, with the ultimate nature of reality and the 'type' of physics best equipped to describe it.
Kumar’s triumph is, seamlessly, to intertwine the arguments this way and that, with the lives of the protagonists and, in the process, illuminate the romance, excitement and processes of scientific endeavour.