Free eBook The Quantum Divide: Why Schrödinger's Cat is Either Dead or Alive By Christopher C. Gerry –

Quantum physics is interesting, fundamental to modern technology and it is a bit weird However, to understand it from a scientific point of view nobody really understands it, hence the quotation marks you do need a little background education in maths and physics no than A level, though, and even then, to get into this book, you only really need to know enough A level science to understand interference phenomena and Young s double slit experiment with some very basic algebra Unfortunately, because of this pre requirent most accounts of quantum physics aimed at the pure layman e.g on TV, the internet and some popular science books tend to over simply their accounts to the point of being wrong about some key concepts Even worse, there is a lot of sensationalist philosophy out there which plays on people s ignorance of actual quantum science and combines this with the fact that there is some weird behaviour in the quantum world to produce sensationalist mystical interpretations of quantum physics and present these interpretations as if they are scientific theories.Not so with this book This book asks that you have a bit of science education to begin with as described above and, in return, it rewards you with a succinct but scientific and non sensationalist non mystical account of quantum physics in about 185 small pages The account is based on the description of key experiments mostly in optics and shows how the results of those experiments cannot be explained by classical physics thereby necessitating an alternative explanation quantum physics which in turn can predict phenomena that have since been demonstrated to be true by further experiments They do also discuss alternative theories to quantum physics in a measured and rational way and explain why, so far, quantum physics is the preferred choice as determined from experimental results to date They introduce key concepts and mathematical notations of the science of quantum theory but in a simplified way You will not have enough detailed knowledge to go away and make your own quantum calculations to predict new phenomena for that you would have to get proper degree level knowledge in the subject but the information and notation they give is sufficient to go away and read some of the professional research papers in the field and almost understand them.I must admit that for me, the going got a bit tough in the later chapters but I sort of followed the gist I would need to re read them and perhaps look up some of the papers they cite to fully grasp what is going on but I do feel that the book has given me the ability to do this I did in fact look up one paper and I actually understood it enough to learn what I needed to know from it.As they freely admit, quantum physics does not explain nature, it merely provides a consistent mathematical framework to describe and predict experimentally observed phenomena at the level of the sub atom with implications for larger systems Some of the key feature of quantum physics like superposition remain counter intuitive and mysterious from an everyday experience point of view However, if you want a sober and scientific account of the subject rather than a sensationalist watered down overview and you have some scientific background knowledge, then this is the book for you A physics undergraduate will probably also benefit from this book as a primer to their main university courses on the subject. Using a selection of key experiments performed over the pastyears or so, we present a discussion of the strikingly counter intuitive phenomena of the quantum world that defy explanation in terms of everyday common sense reasoning, and we provide the corresponding quantum mechanical explanations with a very elementary use of associated formalism Most, but certainly not all, of the experiments we describe are optical experiments involving a very small number of photons particles of light We begin with experiments on the wave particle duality of electrons, proceed to experiments on the particle nature of light and single photon interference, delayed choice experiments and interaction free detection, then go on to experiments involving the interference of two photons, quantum entanglement and Bell s Theorem, quantum teleportation, large scale quantum effects and the divide between the classical and quantum worlds, addressing the question as to whether or not there is such a divide I have a physics degree from 1980 s Saw a recommendation for this Thought it would be good to catch up on current state of QM albeit from a pop perspective minimal maths Especially the measurement problem It almost delivered It ran out of detail too quickly in each chapter though Clearly aimed at the tldr generation You can read the whole book in roughly one self indulgent toilet session But left me unsatisfied as a degree holder of old It also skipped a couple of key steps in some explanations that spoiled a couple of experiment descriptions Having said that, the delayed choice quantum eraser experiment description was awesome If that doesn t truly blow your mind then nothing Move over dull old double split experiment. This book says that it discusses some of the strange aspects of Quantum Mechanics After a general introduction the first part of the book describes experiments to verify that quantum particles namely electrons and particularly photons can produce diffraction patterns where only 1 particle is in the apparatus at a time The book then deals with experiments with entangled photons of different polarizations which establish Quantum Mechanics as a non local theory.The second section pages 132 148 deals with Quantum computing, then Quantum Cryptography and Quantum Teleportation These subjects are treated tersely than the previous and subsequent ones, but extensive bibliography is provided for all sections.The third section on Schr dinger s Cat a sub title of the book starts on page 149 the book has 197 pages including the index and was very clear in my opinion The next topic deals with the experimental verification of Anthony Leggett s a Nobel Laureate for work on super fluids suggestion that superconducting electrons in a Josephson s junction may exhibit Cat Like states in being a linear combination of clockwise and counter clockwise rotating states for about 1 billion electrons.The last section is entitled Quantum Philosophy and concludes with a section entitled The Mystery Remains.Other points on the book Page 123 six lines up from bottom has a sentence That experiment provided the most convincing evidence local hidden variable theory to that date Presumably it should be evidence against A review on the dust jacket says that the book would be useful for professional physicists, students and the educated layman There is a sprinkling of state functions in Dirac ket vector notation and some of these have coefficients involving i the square root of 1, laypersons unfamiliar with these things can still get much from the book but are best informed in advance in my view.Appendix A1 This is a Quantum Mechanics Timeline I have a few comments on this 2 Dirac does not appear at all.3 The Copenhagen Interpretation does not appear in spite of its use in the book.4 Davisson and Germer are credited with establishing electrons exhibited wave behaviour.While this is true G.P Thomson did further work and it was Davisson and Thomson that received the Nobel Prize.5 It mentions briefly near the end the Many Worlds view of Quantum Mechanics but doesn t include it in the TimeLineAppendix.6 Also while it doesn t mention the Path Integral Approach to Quantum Mechanics in the text including it in the Timeline as it is another strange aspect of Quantum Mechanics was possibly an option An exceptionally clear and pragmatic presentation of the mysteries of quantum mechanics told through increasingly mind boggling experimental results There is no maths apart from the use of state vectors to illustrate issues such as entanglement, non locality, cryptography and teleportation The book mainly sticks to the conventional Copenhagen viewpoint and its attractions over other ideas such as implicate order and many worlds while admitting its shortcomings The mysteries remain. Well structured textbook The authors achieved the goal to make the unintuitive ideas of quantum mechanics familiar to a broader audiance throygh the most significant experiments ever carried out. Very nice book Provides a vivid description of experiments demonstrating the nature of quantum mechanics. Great book for beginners and intermediate study of quantum mechanics Anyone who really wants to know the details behind the quantum experiments that prove the fundamental theories, this is the book for you Many of the experiments discussed are surprisingly recent and are about the basic quantum principles not obscure stuff And if you have some background in advanced high school or just undergraduate science and math, it s not hard to understand either Well written, must read for real science nerds Not too much detail or math formulas Also, not really any touchy feely philosophy or human story Just cold hard facts and enough analysis of the experiments to help you understand the significance of the results. This ranks as one of the most difficult of the dozen or so QM popularizations I ve read However, it s also one of the best because it provides genuine insight into QM concepts like superposition entanglement Unlike most popularizations, there s relatively little about the history and personalities involved instead the focus is on explaining QM concepts through modern QM experiments.Difficult is a relative word because there s none of the high level math found in real textbooks So for the laymen, this book may be the closest thing to obtaining real understanding without getting mired in solving the Schrodinger equation Having said that, I ll definitely have to re read this book esp the chapter on entanglement.