I have always been a fan of popular science books, especially the ones in Physics. In my high school days in India, I read entertaining popular science works in Physics by authors from the USSR. I remember particularly those by Ya. Perelman, which clarified many concepts in Physics for me. I can’t remember how many such books I would have read over the years on Quantum Mechanics. Nowadays, quantum computing is very much a real thing. Google, Honeywell and IBM have claimed making limited versions of Quantum computers in the race for quantum supremacy, This book introduces the subject by showing that quantum physics is not an exotic theory, far removed from our experience. Rather, it is something we constantly experience through its effects in our everyday life. The author chooses experiences such as the sunrise, the heating element in a toaster, digital photography, the humble alarm clock, the internet, computer chips, the sense of smell, magnets and the smoke detector to illustrate how ‘quantum’ they are. It is the promise of discovering the quantum in these everyday experiences that encouraged me to read this book.
However, when I did so, I found the book rather tough going. It is popular science only to the extent of 30%. The remaining 70% demands the reader to have a good grounding in the fundamentals of Physics. I felt that it is a semi-serious introduction to quantum mechanics using our everyday experiences as props. Whether the author talks about the sunrise or the smoke detector or the alarm clock, the discussion jumps deep into the science swiftly. It needs the reader to pay a lot more attention to the text than one would have bargained for in a popular science book. In the following paragraphs, I shall try to give a flavor of the book through some of the phenomena under discussion.
The first chapter starts out with the morning sunrise and explains it using the Standard Model of Physics. Particles attract and repulse each other under the influence of the four fundamental forces of Nature. These forces cause stars to collapse into white dwarfs or neutron stars or black holes based on their mass. In this process, electromagnetism holds atoms and molecules together and connects matter to light. It is what sunrise is all about. It comes from the interactions between gravity, electromagnetism, and strong & weak nuclear forces.
I was curious about the chapters on ‘Internet,’ and ‘Computer Chips’ as these are subjects I am more experienced in. My expectation was that they would deal with quantum computing and the impact of quantum physics in the pursuit of Moore’s Law. But the author focuses mainly on the optic fiber networks which carry the bits and bytes. Since most of the data is carried by lasers, the discussion comes down to electromagnetism and atoms again. Discussing computer chips, the book says that it requires a detailed understanding of the physics of electrons inside semiconductors, which depends on their wave nature. When we share pictures of cats over the net, they have a deep connection to the cat of quantum mechanics - Schrödinger’s Cat! Semiconductors and diodes are explained at a molecular level and how molecules emit light at particular wavelengths.
I liked the chapter on Encryption the best, possibly because it is one I understood better than the others. Randomness and probability are fundamental to quantum mechanics. They are also fundamental to encryption. In public key encryption algorithms, we use probabilistic encryption to generate different ciphertexts while encrypting the same message several times. Ultra secure encryption and decryption of messages need a process which allows two widely separated people to generate two lists of random numbers that are nevertheless perfectly correlated. This is what quantum cryptography hopes to achieve through quantum entanglement. This chapter provides the background to entanglement through the famous EPR paper of Einstein, Podolsky, and Rosen. The paper presents a thought experiment to show an inherent paradox in the early formulations of quantum theory. It is among the best-known examples of quantum entanglement. The author says that history subsequently recorded that Einstein & Co were wrong in their arguments. However, he calls it a ‘brilliant mistake’ because it brought to light a strange and troubling aspect of quantum physics that had not been previously considered.
The book covers a lot of light-hearted descriptions of the history of quantum computing through the lives and works of its great pioneers. There are entertaining accounts of anecdotes involving Einstein, Planck, Bohr, Pauli, Schrödinger, Heisenberg and Marie Curie. Contrary to the general impression among the public about Einstein as a Theoretical Physicist and adept in Mathematics, the author says that Einstein’s formal background in physics was more in statistical mechanics, which is the study of the properties of large collections of particles and their behavior. He also quotes the famous mathematician, David Hilbert, as saying that “Every boy in the streets of Göttingen understands more about four-dimensional geometry than Einstein.’
The main thrust of the book is that the quantum is all around us, if only we look. Given this thrust, it is curious that the title of the book refers to Einstein, who expressed skepticism about quantum mechanics than embrace it. Einstein was uncomfortable with its indeterminacy, did not believe that it reflected the fundamental nature of reality, and thought of it as incomplete. He had misgivings about General Relativity too, regarding it as incomplete, and spent his life trying to unify it with Electromagnetism. Considering all this, I would have thought ‘Breakfast in Copenhagen’ could have been a more appropriate title for the book, in honor of Niels Bohr’s team in Copenhagen.
I read the book because of its title. I thought it may cover photoelectric effect, General Relativity, quantum entanglement and his unfinished work on the Unified Field theory. In recent years, we have seen Einstein’s ideas coming good in Astronomy with Gravitational Lensing. Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity. Exactly one hundred years later, in 2016, the LIGO detected Gravitational waves. In 2019, the Event Horizon telescope showed the first-ever images of a black hole confirming many facets of General Relativity. This book does not deal with any of them, though. It does not touch on the disappointing results from the Large Hadron Collider so far on Super Symmetry or dark matter particles. Nor does it discuss the tendency in Theoretical Physics without worrying too much about experimental verification.
Summing up, without a strong grounding in the fundamentals of Modern Physics, I think it would be difficult for a reader to enjoy or even fully understand this book. We should bear this in mind before embarking on reading it.