Einstein for Everyone


JOHN D. NORTON







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Nullarbor Press
2007
revisions 2008, 2010, 2011, 2012







Copyright 2007, 2008, 2010, 2011, 2012 John D. Norton
Published by Nullarbor Press, 500 Fifth Avenue, Pittsburgh, Pennsylvania 15260
with offices in Liberty Ave., Pittsburgh, Pennsylvania, 15222

All Rights Reserved



John D. Norton
Center for Philosophy of Science
Department of History and Philosophy of Science
University of Pittsburgh
Pittsburgh PA USA 15260





An advanced sequel is planned in this series:
Einstein for Almost Everyone















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no trees were harmed

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This book is a continuing work in progress. When I have time, I edit, expand and add to the chapters. For the convenience of readers who need a stable version that will not change, there are archived versions, which are snapshots of the state of the book at the date indicated:

January 1, 2012.


























Preface

For over a decade I have taught an introductory, undergraduate class, "Einstein for Everyone," at the University of Pittsburgh to anyone interested enough to walk through door. The course is aimed at people who have a strong sense that what Einstein did changed everything. However they do not know enough physics to understand what he did and why it was so important. The course presents just enough of Einstein's physics to give students an independent sense of what he achieved and what he did not achieve. The latter is almost as important as the former. For almost everyone with some foundational axe to grind finds a way to argue that what Einstein did vindicates their view. They certainly cannot all be right. Some independent understanding of Einstein's physics is needed to separate the real insights from the never-ending hogwash that seems to rain down on us all.

With each new offering of the course, I had the chance to find out what content worked and which of my ever so clever pedagogical inventions were failures. By this slow process of trial and error, indulging the indefinitely elastic patience of the students at the University of Pittsburgh, the course has grown to be something that works pretty well--or so it seems from my side of the lectern.

At the same time, my lecture notes have evolved. They began as chaotic pencil jottings. Over time they solidified into neater pencil script and overhead transparencies; and then into summaries that I posted on my website; and then finally those summaries were expanded into a full text that can be read independently. That text is presented here.

Its content reflects the fact that my interest lies in history and philosophy of science and that I teach in a Department of History and Philosophy of Science. There is a lot of straight exposition of Einstein's physics and the physics it inspired. However there is also a serious interest in the history of Einstein's science. A great deal of my professional life has been spent poring over Einstein's manuscripts, trying to discern how he found what he found. The results of those studies have crept in. In other places I try to show how a professional philosopher approaches deeply intractable foundational issues. The temptation in such cases is to let one's standard of rigor drop, since otherwise it seems impossible to arrive at any decision. That is exactly the wrong reaction. When the problems are intractable, we must redouble our commitment to rigor in thought; and I have tried to show how we can do this.

This text owes a lot to many. It came about because, years ago, Peter Machamer, then chair of the Department of HPS, urged a meandering junior professor to teach a course that "did" Einstein and black holes and all that stuff. The text is indebted to the University of Pittsburgh, which has the real wisdom to see that it gets the most from its faculty by letting them do what fascinates them, for they will surely do that best. It owes the greatest debt to the infinite patience of the students who have taken this class, told me what works and what does not, and each year allowed me, at least indirectly, to experience anew that inescapable sense of wonder when one first grasps the beauty of what Einstein did.

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Contents

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1. Introduction read
2. Special Relativity: The Basics read
3. Special Relativity: Adding Velocities read
4. Special Relativity: Relativity of Simultaneity read
5. Is Special Relativity Paradoxical? read
6. E=mc2 read
7. Origins of Special Relativity read
8. Einstein's Pathway to Special Relativity read
9. Spacetime read
10. Spacetime and the Relativity of Simultaneity read
11. Spacetime, Tachyons, Twins and Clocks read
12. What is a Four Dimensional Space Like? read
13. Philosophical Significance of the Special Theory of Relativity read
14. Euclidean Geometry: The First Great Science read
15. Non-Euclidean Geometry: A Sample Construction read
16. Spaces of Constant Curvature read
17. Spaces of Variable Curvature read
18. General Relativity read
19. Gravity Near a Massive Body read
20. Einstein's Pathway to General Relativity read
21. Relativistic Cosmology read
22. Big Bang Cosmology read
23. Black Holes read
24. A Better Picture of Black Holes read
25. Atoms and the Quanta read
26. Origins of Quantum Theory read
27. Quantum Theory of Waves and Particles read
28. The Measurement Problem read
29. Einstein on the Completeness of Quantum Theory read
30. Einstein as the Greatest of the Nineteenth Century Physicists read

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