Seven Brief Lessons on Physics

Amazing book and easy to follow. I particularly liked the first chapter about Einstein's Theory in which he was originally trying to find the field of gravity, and then discovered that SPACE is it. The books simplicity is very suitable for beginners and readers who are fascinated by physics/ astrophysics but not necessarily have un educational foundation.

It is an excellent book. It gives great insights in simple language. Some may feel it to be too simplistic or plain. But if one has put some genuine thought or effort to make head or tail out of these baffling theories, then he/she would understand that the insights given in the book are the core ideas of these baffling concepts. The book gives more than a hint why all these seemingly absurd concepts in relativity or quantum mechanics (their mutual contradiction) arise. It is a light read, gives the feel of the thought process... A small book that excellently rounds up the conceptual foundations on which present day physics stands.

知らない単語が出てくる頻度が少ない そして興味深い 洋書を初めて読む人にもおすすめ

J'ai lu des tas de livres sur ce sujet, ai travaillé au CERN, et ce livre sort du lot par sa clarté exprimée en peu de mots et quelques figures. Je compte le recommander à mon entourage car c'est de loin l'exposé le plus facile à lire que j'ai lu sur ces sujets complexes. Chapeau bas à l'auteur, vraiment!! Je vais lire le reste de ses livres sans aucun doute! A lire absolument!

La capacità dello scrittore di coinvolgere il lettore in un tema difficile quale può essere la fisica e riflettere sul senso della vita

The book is addressed to the general reader with little knowledge of modern science. It provides an overview of the revolution of Physics in the twentieth century while concurrently reveals the enormity of the unknown. In the ensuing I shall concentrate on the two most significant revolutions in Physics the twentieth century namely Einstein's General Theory of Relativity and Quantum Mechanics while I shall conclude by touching on the last chapter of the book namely 'Ourselves' and citing the last paragraph of the book to provide a taste of its literary beauty. Newton tried to explain the reason why things fall and planets turn. He imagined the existence of a force which draws all material objects towards one another and called it the force of gravity. Newton also imagined that bodies move through space, and that space is a great empty container. Few years before the birth of Einstein two British physicists, Michael Faraday and James Maxwell, had added a key ingredient to Newton's world: the electromagnetic field. This field is a real entity which, diffused everywhere, carries radio waves, fills space, can vibrate and oscillate and transports the electric force. Einstein was fascinated by the electromagnetic field and came to appreciate that gravity, like electricity, must be conveyed by a field, a gravitational field analogous to the electric field. Then in a stroke of genius, Einstein visualized that the gravitational field is not diffused through space; that gravitational field is that space itself. This is the idea of the General Theory of Relativity. A momentous simplification of the world: space is not something distinct from matter, it is one of the material components of the world. An entity that undulates, flexes, curves, twists. The sun bends space around itself and earth glides in a space which inclines. Planets circle around the sun, and things fall, because space curves. Due to this curvature, not only planets orbit around the sun, but light stops moving in a straight line and deviates. But it is not only space that curves; time does too. Einstein predicted that time passes more quickly high up than below, nearer to earth. The predictions of the Theory of General Relativity verified experimentally with an amazing precision of one part to one hundred billion. The theory describes an equally amazing world when universes explode, space collapses into bottomless holes - black holes, time sags and slows near a planet, and the unbounded extensions of interstellar space ripple and sway like the surface of sea while the space expands. The second pillar of twentieth century physics is Quantum Mechanics. Both theories reveal that the fine structure of nature is more subtle than it appears. But similarities end there. The Theory of General Relativity is the ultimate of elegance: it is a simple and coherent vision of gravity, space and time. Quantum Mechanics, on the other hand, has gained unequaled experimental success and lead to applications which transformed our every day life such as the transistors and the computer; yet more than a century after its birth it remains shrouded in mystery and incomprehensibility. In 1900 Max Planck calculated the electric field in equilibrium in a hot box - and as calculating trick - imagined the energy of the field as distributed in quanta, that is in packs or lumps of energy. The procedure lead to a result that perfectly reproduced. Subsequently Einstein showed that light is made of packets: particles of light called today photons. But it was the Dane Niels Bohr who pioneered its development. It was Bohr who understood that the energy of electrons in atoms can only take on certain values, like the energy of light, and crucially that electrons can only jump between one atomic orbit and another with fixed energies, emitting or absorbing a photon when they jump. In 1925 the equations of the theory finally appeared, replacing the entire mechanics of Newton. It is difficult to imagine a greater achievement. At one stroke, everything makes sense, and you can calculate everything. Take one example: the periodic table of elements, devised by Mendeleev, which lists all possible elements of which the universe is made, from hydrogen to uranium. Why are these elements listed here and why does the periodic table have this particular structure, with these periods, and with the elements having these specific properties? The answer is that each element corresponds to one solution of the main equation of the quantum mechanics. The whole Chemistry emerges from a single equation. The first to write the equation of the new theory, would be a young German of genius, Werner Heisenberg. Heisenberg imagined that electrons do not always exist. They only exist when they are interacting with something else. They materialize in place, with calculable probability, when colliding with something else. The quantum leaps from one orbit to another are the only means they have of being real: an electron is a set of jumps from one interaction to another. When nothing disturbs it, it is not in any precise place. It is not in a place at all. In order to describe it in mid flight, between one interaction and another, we use an abstract mathematical formula which has no existence in real space, only in abstract mathematical space. But not only that: these interactive leaps with which each object passes from one place to another do not occur in a predictable way but largely at random. It is not possible to predict where an electron will reappear, but only to calculate the probability that it will pop up here or there. The question of probability goes to the heart of Physics, while previously everything had seemed to be regulated by firm laws which were universal and irrevocable. What does this mean? That the essential reality of a system is indescribable? Does it mean that we only lack a piece of the puzzle? Or does it mean, as the author is inclined to think, that we must accept the idea that reality is only interaction? The final chapter of the book is both philosophical and insightful. We have to realize that we are an integral part of the world which we perceive; we are not external observers, we are situated within it. Our view of it is from within its mist. Between what we can reconstruct with our limited means and the reality of which we are part, there exist countless filters: our ignorance, the limitation of our senses and f our intelligence. The only way forward to the path of reality is through science. The book comes to an end with the paragraph: 'There are frontiers where we are learning, and our desire for knowledge burns. They are in the most minute reaches of the fabric of space, at the origin of the cosmos, in the nature of time, in the phenomenon of black holes, and in the workings of our thought processes. Here, on the edge of what we know, in contact with the ocean of the unknown shines the mystery and beauty of the world. And it's breathtaking.'