Einstein for Everyone
JOHN D. NORTON
Nullarbor Press
2007
revisions 2008, 2010, 2011, 2012, 2013
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 For the convenience of readers who need a stable version that will not change, there is an archived version, which is a snapshot of the state of the book at the date indicated:
January 1, 2015.
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 neverending 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 wellor 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.
i i i
Contents
Preface  iii 
1. Introduction  read 
Special Relativity  
2. Special Relativity: The Principles  read 
3. Special Relativity: Clocks and Rods  read 
4. Special Relativity: Adding Velocities  read 
5. Special Relativity: Relativity of Simultaneity  read 
6. Is Special Relativity Paradoxical?  read 
7. E=mc^{2}  read 
8. Origins of Special Relativity  read 
9. Einstein's Pathway to Special Relativity  read 
Spacetime  
10. Spacetime  read 
11. Spacetime and the Relativity of Simultaneity  read 
12. Spacetime, Tachyons, Twins and Clocks  read 
13. What is a Four Dimensional Space Like?  read 
Philosophical Significance of the Special Theory of Relativity 

14. Skeptical Morals  read 
15. Morals About Theory and Evidence  read 
16. Morals about Time  read 
NonEuclidean Geometry  
17. Euclidean Geometry: The First Great Science  read 
18. Euclid's Fifth Postulate  read 
19. NonEuclidean Geometry: A Sample Construction  read 
20.NonEuclidean Geometry and Curved Spaces  read 
21. Spaces of Constant Curvature  read 
22. Spaces of Variable Curvature  read 
General Relativity  
23. General Relativity  read 
24. Gravity Near a Massive Body  read 
25. Einstein's Pathway to General Relativity  read 
Cosmology and Black Holes  
26. Relativistic Cosmology  read 
27. Our Universe: What We See  read 
28. Big Bang Cosmology  read 
29. Must There Have Been a Big Bang?  read 
30. Black Holes  read 
31. A Better Picture of Black Holes  read 
Philosophical Significance of the General Theory of Relativity 

32. Geometric Morals and a few more  read 
Quantum Theory  
33. Atoms and the Quanta  read 
34. Origins of Quantum Theory  read 
35. Quantum Theory of Waves and Particles  read 
36. The Measurement Problem  read 
37. Einstein on the Completeness of Quantum Theory  read 
38. Einstein as the Greatest of the Nineteenth Century Physicists  read 
i v