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Christoph Schiller MOTION MOUNTAIN the adventure of physics – vol.iv the quantum of change www.motionmountain.net Christoph Schiller Motion Mountain The Adventure of Physics Volume IV The Quantum of Change Edition 25.30, available as free pdf at www.motionmountain.net Editio vicesima quinta. Proprietas scriptoris © Chrestophori Schiller primo anno Olympiadis trigesimae. Omnia proprietatis iura reservantur et vindicantur. Imitatio prohibita sine auctoris permissione. Non licet pecuniam expetere pro aliqua, quae partem horum verborum continet; liber pro omnibus semper gratuitus erat et manet. Twenty-fifth edition. Copyright © 2012 by Christoph Schiller, the first year of the 30th Olympiad. This pdf file is licensed under the Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 Germany Licence,whosefulltextcanbefoundonthewebsite creativecommons.org/licenses/by-nc-nd/3.0/de, with the additional restriction that reproduction, distribution and use, in whole or in part, in any product or service, be it commercial or not, is not allowed without the written consent of the copyright owner. The pdf file was and remains free for everybody to read, store and print for personal use, and to distribute electronically, but only in unmodified form and at no charge. To Britta, Esther and Justus Aaron τῷ ἐμοὶ δαὶμονι Die Menschen stärken, die Sachen klären. PREFACE Primum movere, deinde docere.* Antiquity “ ” Motion Mountain – The Adventure of Physics pdf file available free of charg This book is written for anybody who is curious about nature and motion. Have you ever asked: Why do people, animals, things, images and space move? The answer leads to many adventures; this volume presents those due to the discovery that there is a smallest change value in nature. This smallest change value, the quantum of action, leads to what is called quantum physics.Inthestructureofmodernphysics,showninFigure 1,quantum physics covers three points; this volume covers the introduction to the point in the lower right: the foundations of quantum theory. The present introduction to quantum physics arose from a threefold aim I have pur- sued since 1990: to present the basics of motion in a way that is simple, up to date and captivating. In order to be simple, the text focuses on concepts, while keeping mathematics to the necessary minimum. Understanding the concepts of physics is given precedence over using formulae in calculations. The whole text is within the reach of an undergraduate. In order to be up to date, the text is enriched by the many gems – both theoretical and empirical – that are scattered throughout the scientific literature. In order to be captivating, the text tries to startle the reader as much as possible. Read- e at www.motionmountain.net Copyright © Christoph Schiller June 1990–Nove ing a book on general physics should be like going to a magic show. We watch, we are astonished, we do not believe our eyes, we think, and finally we understand the trick. When we look at nature, we often have the same experience. Indeed, every page presents at least one surprise or provocation for the reader to think about. Numerous interesting challenges are proposed. The motto of the text, die Menschen stärken, die Sachen klären,afamousstatementby Hartmut von Hentig on pedagogy, translates as: ‘To fortify people, to clarify things.’ Clar- ifying things – and adhering only to the truth – requires courage, as changing the habits of thought produces fear, often hidden by anger. But by overcoming our fears we grow in strength. And we experience intense and beautiful emotions. All great adventures in life allow this, and exploring motion is one of them. Enjoy it! Munich, 1 November 2012. mber 2012 * ‘First move, then teach.’ In modern languages, the mentioned type of moving (the heart) is called motivat- ing;bothtermsgobacktothesameLatinroot. 8 preface PHYSICS: Final, unified description of Why does motion Describing motion motion occur? What are with the least action principle. Adventures: understanding space, time and motion, intense joy with quantum particles? thinking, calculating couplings and masses, catching a glimpse of bliss (vol. VI). Quantum General relativity theory with gravity Quantum field theory Adventures: the Adventures: bouncing Adventures: building night sky, measu- neutrons, under- accelerators, under- standing tree standing quarks, stars, ring curved space, Motion Mountain – The Adventure of Physics pdf file available free of charg exploring black growth (vol. V). bombs and the basis of holes and the life, matter, radiation universe, space (vol. V). and time (vol. II). How do small things move? What are things? How do Classical gravity everyday, Special relativity Quantum theory Adventures: fast and large Adventures: light, Adventures: death, climbing, skiing, things move? magnetism, length reproduction, biology, space travel, contraction, time chemistry, evolution, the wonders of dilation and enjoying colours and 2 astronomy and E0 = mc (vol. II). art, all high-tech geology (vol. I). business, medicine G c h, e, k (vol. IV and V). Galilean physics, heat and electricity Adventures: sport, music, sailing, cooking, e at www.motionmountain.net Copyright © Christoph Schiller June 1990–Nove describing beauty and understanding its origin (vol. I), using electricity, light and computers, understanding the brain and people (vol. III). FIGURE 1 A complete map of physics: the connections are defined by the speed of light c,the gravitational constant G, the Planck constant h, the Boltzmann constant k and the elementary charge e. Advice for learners In my experience as a teacher, there was one learning method that never failed to trans- form unsuccessful pupils into successful ones: if you read a book for study, summarize every section you read, in your own images and words, aloud.Ifyouareunabletodo so, read the section again. Repeat this until you can clearly summarize what you read in your own images and words, aloud. You can do this alone in a room, or with friends, or while walking. If you do this with everything you read, you will reduce your learning and reading time significantly. mber 2012 The most inefficient learning method is to use a marker or to underline text: it wastes time, provides false comfort and makes the text unreadable. Nobody marking text is an preface 9 efficient learner. Instead, by repeating every section in your own images and words, aloud, youwillsavetimeandmoney,enjoylearningfromgoodtextsmuchmoreandhatebad texts much less. Masters of the method can use it even while listening to a lecture, in a low voice, thus avoiding to ever take notes. Using this book Text in green, as found in many marginal notes, marks a link that can be clicked in a pdf reader. Such green links are either bibliographic references, footnotes, cross references to other pages, challenge solutions, or pointers to websites. Solutions and hints for challenges are given in the appendix. Challenges are classified as research level (r), difficult (d), standard student level (s) and easy (e). Challenges of type r, d or s for which no solution has yet been included in the book are marked (ny). Motion Mountain – The Adventure of Physics pdf file available free of charg Feedback and support This text is and will remain free to download from the internet. I would be delighted to receive an email from you at [email protected], especially on the following issues: Challenge 1 s — What was unclear and should be improved? — What story, topic, riddle, picture or movie did you miss? — What should be corrected? In order to simplify annotations, the pdf file allows adding yellow sticker notes in Adobe Reader. Alternatively, you can provide feedback on www.motionmountain.net/ wiki.Helponthespecificpointslistedonthewww.motionmountain.net/help.html web page would be particularly welcome. All feedback will be used to improve the next edi- tion. On behalf of all readers, thank you in advance for your input. For a particularly useful contribution you will be mentioned – if you want – in the acknowledgements, e at www.motionmountain.net Copyright © Christoph Schiller June 1990–Nove receive a reward, or both. Your donation to the charitable, tax-exempt non-profit organisation that produces, translates and publishes this book series is welcome! For details, see the web page www. motionmountain.net/donation.html. If you want, your name will be included in the sponsor list. Thank you in advance for your help, on behalf of all readers across the world. A paper edition of this book, printed on demand and delivered by mail to any ad- dress, can be ordered at www.lulu.com/spotlight/motionmountain.Butaboveall,enjoy the reading! mber 2012 Contents 14 1 Minimum action – quantum theory for poets The effects of the quantum of action on rest 17 • The consequences of the quantum of action for objects 18 • Why ‘quantum’? 20 • The effect of the quantum of action on motion 22 • The surprises of the quantum of action 24 • Transformation, life and Democritus 26 • Randomness – a consequence of the quantum of action 29 • Waves – a consequence of the quantum of action 30 •Particles–aconsequenceof the quantum of action 32 • Quantum information 33 • Curiosities and fun chal- lenges about the quantum of action 34 • The dangers of buying a can of beans 35 • A summary: quantum physics, the law and indoctrination 36 38 2 Light – the strange consequences of the quantum of action How do faint lamps behave? 38 •Photons 42 •Whatislight? 44 •Thesize Motion Mountain – The Adventure of Physics pdf file
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