History of 20th Century Physics

Fall 2000 class taught by Michel Janssen, University of Minnesota.

Note: syllabi dates have been removed, be sure to insert your relevant dates in where necessary.

Course Description (back to top)

This course is an introduction to the work of historians and philosophers of science trying to trace the conceptual development of 20th century physics. Our main focus will be on the development of relativity theory (both special and general) and quantum theory in the first quarter of the century. Special attention will be paid to the contributions of Albert Einstein. Readings are taken from a variety of sources. General surveys are used to get us started on a particular topic (for a list of these topics, see the "Schedule" on pp. 3-10 below). That will prepare us for more specialized literature in history and philosophy of science. We will also read (passages from) some of the seminal texts written by the physicists we will study, both to get some of the flavor of their work and to evaluate interpretations and reconstructions of these texts offered in the historical and philosophical literature.

Course Format (back to top)

The course will basically be run as a lecture course, but with ample opportunity for discussion. Class presentations are not required, but volunteers are welcome. Sessions 4, 8, and 9 (see "Schedule" below) are especially suitable for student presentations, as well as—depending on your background—sessions 10, 14, and 15.

Course Requirements (back to top)

The basic requirement for this class is to keep up with the reading assignments (see "Schedule" below). Do the reading for any given week before you come to class, so that you are well prepared to follow the lecture and to participate in discussion. There will be three take-home exams that will test your understanding of the readings and the discussion of them in class. These exams will consist of 2-4 essay questions each requiring an answer of 1-3 typed, double-spaced pages. The 1st take-home will be on the material covered in weeks 1-5, and will handed out at the end of class; due one week later. The 2nd take-home will be on the material covered in weeks 6-10, and will be handed out at the end of class; due one week later. The 3rd take-home will be on the material covered in weeks 11-15, and will be handed out at the end of the last day of class; due one week later at 5 PM. If you volunteer to do a class presentation, you have the option of substituting your presentation for parts of one of these take home exams.

Additional requirement for graduate students: in addition to the above, graduate students are required to write a 10-20 page (double-spaced) paper on any topic in the history of 20th century physics (it can but does not have to be in an area covered in class). A short proposal for your paper (including a list of sources to be consulted) is due at the beginning of class November 21. You are encouraged to discuss a possible topic with me earlier in the semester. I will pass out a style sheet with suggestions for footnote and citation formats. The paper is due when the final exams are due, at 5pm.

Grading (back to top)

Undergraduate Students: 3 take-home exams (30% each); class participation (10%).

Graduate Students: paper (30%); 3 take-home exams (20% each); class participation (10%).

All grades will initially be given on a scale from 0 to 100 and will only in the end be converted to letter grades. The conversion will roughly be as follows: 80-100: A; 70-80: B; 60-70: C; 50-60: D; less than 50: F.

Course Books (back to top)

1. Helge Kragh, Quantum Generations. A History of Physics in the Twentieth Century. Princeton: Princeton University Press, 1999.

2. Emilio Segrè, From X-rays to Quarks. Modern Physicists and Their Discoveries. San Francisco: W. H. Freeman and Company, 1980.

3. Andrew Pickering, Constructing Quarks. A Sociological History of Particle Physics. Chicago: University of Chicago Press, 1984.

4. Albert Einstein et al., The Principle of Relativity. New York: Dover, 1952.

5. Paul and Tatiana Ehrenfest, The Conceptual Foundations of the Statistical Approach in Mechanics. New York: Dover, 1990.

6. B.L. van der Waerden, Sources of Quantum Mechanics. New York: Dover, 1968.

Items 1 & 3-6 should be available at the bookstore. Item 2 is out of print. You will be able to borrow a copy from Prof. Stuewer's personal library. Do not write in these copies! A photocopy of readings from other sources (see "Schedule" below) will be available in the office of Barbara Eastwold (Tate Laboratory of Physics, Rm. 381) one week before the session in which the material is covered (with the obvious exception of the first class).

Attendance (back to top)

Since the discussion of the assigned readings in class is an integral part of the course, attendance is mandatory. Attendance sheets will be passed out at the beginning of each class. Unexcused absences will be reflected in your grade for class participation. More importantly, missing class will put you at a disadvantage when writing your short essays for the take-home exams.

Office Hours (back to top)

If you have difficulty with the material, do not wait too long and come see me during office hours. I will do my best to answer any questions you may have, from very specific ones to "I'm lost!"

Note on Plagiarism (back to top)

Present your own ideas and your own arguments and present them in your own words. Use quotations sparingly and give detailed citations whenever you do. Note that simply changing a few words in a quotation does not change the fact that you are quoting. Paraphrasing of this sort, where you use a source almost verbatim without acknowledgment, is the most common form of plagiarism among undergraduates. Another common problem may arise from collaborating with other students. You are free to discuss the take-home exams with other students but the work that you submit must be your own, not something jointly written or copied from another student. You will not receive any credit for work that violates these rules against plagiarism.

Schedule (back to top)

For each week, a number of readings are listed. The readings are divided into three categories labeled A, B, and C. The ones under A should be read by all students. Graduate students are also expected to read those under B. These are optional for undergraduate students. However, since I will typically draw on the readings under both A and B in class, undergraduate students are strongly encouraged to read as much as they can from the readings under B. Readings under C are suggestions for further reading.

Week 1: Introduction and 19th Century Ether Theories

Michel Janssen and John Stachel, "The Optics and Electrodynamics of Moving Bodies." To appear in Sandro Petruccioli (ed.), Storia Della Scienza. Instituto della Enciclopedia Italiana.

H. A. Lorentz, "Michelson's Interference Experiment." In: Einstein et al. 1952, pp. 3-7.

Week 2: Lorentz Invariance: Einstein, Lorentz and Minkowski

Michel Janssen, "Reconsidering a Scientific Revolution: the Case of Lorentz versus Einstein." To appear in Physics in Perspective.

Albert Einstein, "On the Electrodynamics of Moving Bodies." Kinematical Part, secs. 1-5. Einstein et al. 1952, pp. 37-51.

———, "What is the Theory of Relativity?" In Albert Einstein, Ideas and Opinions. New York, Bonanza, [no year given], pp. 227-232.

Michel Janssen, "The Postulates of STR and Their Strange Consequences." Handout for course Einstein for Everyone. ———, "STR and Minkowski Space-Time." Handout for course Einstein for Everyone. Secs. 1-7.


Hermann Minkowski, "Space and Time." Einstein et al. 1952, 75-91.

John Stachel et al. (eds.), The Collected Papers of Albert Einstein. Vol. 2. The Swiss Years: Writings, 1900-1909. Princeton: Princeton University Press, 1989. Editorial note: "Einstein on the Theory of Relativity," pp. 253-274.

Abraham Pais, 'Subtle is the Lord ...' The Science and the Life of Albert Einstein. Oxford: Clarendon Press; New York: Oxford University Press, 1982 (best scientific Einstein biography)

Albrecht Fölsing, Albert Einstein. A Biography. New York: Viking, 1997 (best general Einstein biography)

Week 3: The Electromagnetic World View Versus Relativistic Mechanics

Kragh 1999, Ch. 7, pp. 87-104 ("Einstein's Relativity, and Others'") and Ch. 8, pp. 105-119 ("A Revolution that Failed").

Segrè 1980, Ch. 5, pp. 78-100 ("Einstein—New Ways of Thinking: Space, Time, Relativity, and Quanta").

B Michel Janssen, "The Trouton Experiment, E = mc 2 , and a Slice of Minkowski Space-time" To appear in Boston Studies in the Philosophy of Science. Secs. 1-6.
C Arthur I. Miller, Albert Einstein's Special Theory of Relativity. Emergence (1905) and Early Interpretation (1905-1911). Secs. 1.8-1.14, pp. 45-86; Secs. 7.4.1-7.4.3, pp. 225-235; Sec. 12.4, pp. 334-352.
Week 4: Cathode Rays, X-rays, and Radioactivity

Kragh 1999, Chs. 1-3, pp. 3-43 ("Fin-de-Siècle Physics: A World Picture in Flux;" "The World of Physics;" "Discharges in Gases and What Followed").

Segrè 1980, Chs. 1 and 2, pp. 1-45 ("Introduction" [Zeeman, Thomson, Röntgen]; "Becquerel, the Curies, and the Discovery of Radioactivity").

Wesley Salmon, Scientific Explanation and the Causal Structure of the World. Princeton: Princeton University Press, 1984. Ch. 8, pp. 206-238, "Theoretical Explanation" (in particular pp. 213-227, "The Common Cause Principle and Molecular Reality,").


H. A. Boorse and L. Motz (eds.), The World of the Atom. Vol. I. New York: Basic Books, 1966. Pp. 389-407: papers by Röntgen and Becquerel.

G. K. T. Conn and H. D. Turner (eds.), The Evolution of the Nuclear Atom. London: Iliffe Books, 1965. Pp. 29-64: papers by Perrin and Thomson.

C Abraham Pais, Inward Bound. Of Matter and Forces in the Physical World. Oxford: Clarendon Press; New York: Oxford University Press, 1982. Chs. 2-4, pp. 35-92.
Week 5: Planck and Black-Body Radiation

Kragh 1999, Ch. 5, pp. 58-73 ("The Slow Rise of Quantum Theory")

Segrè 1980, Ch. 4, pp. 61-77 ("Planck, Unwilling Revolutionary: The Idea of Quantization"), Appendix 2, pp. 300-301 ("Planck's Hunt for the Blackbody Radiation Formula").

Martin J. Klein, "The Beginnings of Quantum Theory." In C. Weiner (ed.), Proceedings of the International School of Physics "Enrico Fermi" 1972: History of Twentieth Century Physics. New York and London: Academic Press, 1977. Sec. 1, pp. 1-19 ("Planck and the Quantization of Energy"), especially pp. 16-19, the appendix.

Thomas S. Kuhn, Blackbody Theory and the Quantum Discontinuity, 1894-1912. Chicago: University of Chicago Press, 1987. Pp. 102-110 ("Deriving the distribution law"); pp. 349-370 ("Afterword: Revisiting Planck").

Martin J. Klein, Abner Shimony, and Trevor Pinch, "Paradigm Lost? A Review Symposium." Isis 70 (1969) 429-440.


Hans Kangro (ed.) with D. ter Haar, and Stephen Brush (transl.), Planck's Original Papers in Quantum Physics. London: Taylor & Francis, 1972. Pp. 35-60. Planck's first two papers on his new black-body radiation law in 1900.

Morris H. Shamos (ed.), Great Experiments in Physics. Firsthand Accounts from Galileo to Einstein. New York: Dover, 1959. Planck's Annalen paper of 1901

Peter Galison, "Kuhn and the Quantum Controversy." British Journal for the Philosophy of Science 32 (1981): 71-85.


Olivier Darrigol, From c-Numbers to q-Numbers. The Classical Analogy in the History of Quantum Theory. Berkeley: University of California Press, 1992. Part A, pp. 3-77 ("Planck's Radiation Theory").

Allan A. Needell, Irreversibility and the Failure of Classical Dynamics: Max Planck's Work on the Quantum Theory 1900-1915. Ph.D. Thesis. Yale University, 1980. (Available through UMI Dissertation Services).

———. "Introduction" (pp. xi-xlv) to Max Planck, The Theory of Heat Radiation. Los Angeles: Tomash Publishers; New York: American Institute of Physics, 1988.

Max Planck, "Zur Geschichte der Auffindung des physikalischen Wirkungsquantums." In: Vorträge und Erinnerungen. Pp. 15-27. Darmstadt: Wissenschaftliche Buchgesellschaft, 1965 (I have not been able to locate a translation so far).

John L. Heilbron, The Dilemmas of an Upright Man. Max Planck as Spokesman for German Science. Berkeley: University of California Press, 1986.

Week 6: The Ehrenfests on Statistical Mechanics

Martin J. Klein, Paul Ehrenfest. Vol. 1. The Making of a Theoretical Physicist. Amsterdam: North Holland, 1970. Ch. 6, pp. 94-140 ("The Critic of Statistical Mechanics").

Olivier Darrigol and Jürgen Renn, "The Emergence of Statistical Mechanics." To appear in Sandro Petruccioli (ed.), Storia Della Scienza. Instituto della Enciclopedia Italiana.

B Paul and Tatiana Ehrenfest, The Conceptual Foundations of the Statistical Approach in Mechanics. New York: Dover, 1990. Introduction plus secs. I and II, pp. 1-42.

Martin J. Klein, "The development of Boltzmann's statistical ideas." In E.G.D. Cohen and W. Thirring (eds.), The Boltzmann equation: theory and application. New York: Springer-Verlag. Pp. 53-106.

Lawrence Sklar, Physics and Chance. Philosophical Issues in the Foundations of Statistical Mechanics. Cambridge: Cambridge University Press, 1993.

Week 7: Einstein and the Light Quantum

Martin J. Klein, "Einstein's First Paper on Quanta." The Natural Philosopher 2 (1963): 59-86.

Martin J. Klein, "Einstein and the Wave-Particle Duality." The Natural Philosopher 3 (1964): 1-49.

Segrè 1980, Appendices 3 ("Heuristic Argument for Postulating the Existence of Light Quanta") 5 ("Blackbody Energy Fluctuations") 6 ("Specific Heats of Solids") and 7 ("A and B Coefficients").


Albert Einstein, "Concerning a Heuristic Point of View about the Creation and Transformation of Light" (1905) Doc. 14 in Vol. 2 of Einstein edition, translation on pp. 86-103 of companion volume.

———, "On the Quantum Theory of Radiation." (1917) In Van der Waerden 1968, pp. 63-77.

Jon Dorling, "Einstein's Introduction of Photons: Argument by Analogy or Deduction from the Phenomena?" British Journal for the Philosophy of Science 22 (1971): 1-8.


John Stachel et al. (eds.), The Collected Papers of Albert Einstein. Vol. 2. The Swiss Years: Writings, 1900-1909. Princeton: Princeton University Press, 1989. Editorial note: "Einstein's Early Work on the Quantum Hypothesis," pp. 134-148.

Martin J. Klein, "Einstein, Specific Heats, and the Early Quantum Theory." Science 148 (1965): 173-180.

Albert Einstein, "On the Theory of Light Production and Light Absorption." (1906) Doc. 34 in Vol. 2 of Einstein edition, translation on pp. 192-199 of companion volume.

———, "Planck's Theory of Radiation and the Theory of Specific Heat" (1907) Doc. 38 in Vol. 2 of Einstein edition, translation on pp. 214-224 of companion volume.

———, "On the Present Status of the Radiation Problem." (1909) Doc. 56 in Vol. 2 of Einstein edition, translation on pp. 357-375 of companion volume.

———, "On the Development of Our Views Concerning the Nature and Constitution of Radiation." (1909) Doc. 60 in Vol. 2 of Einstein edition, translation on pp. 379-394 of companion volume.

Week 8: Atomic Models: Rutherford and Bohr

Kragh 1999, Ch. 4, pp. 44-57 ("Atomic Architecture")

Segrè 1980, Ch. 3, pp. 46-60 ("Rutherford in the New World: The Transmutation of Elements"), Chs. 6-7, pp. 101-148 ("Sir Ernest and Lord Rutherford of Nelson;" "Bohr and Atomic Models"), Appendix 9 ("Bohr's Hydrogen Atom").


John Heilbron and Thomas S. Kuhn, "The Genesis of the Bohr Atom." Historical Studies in the Physical Sciences 1 (1969): 211-290.

Niels Bohr, "On the Constitution of Atoms and Molecules." Philosophical Magazine 26 (1913): 1-25. Reprinted in J. B. Birks (ed.), Rutherford at Manchester. New York: Benjamin, 1963. Pp. 228-256.

Ernest Rutherford, "The Scattering of a and b Particles by Matter and the Structure of the Atom."

Week 9: The Compton Effect and the Transition to Quantum Mechanics
A Martin J. Klein, "The First Phase of the Bohr-Einstein Dialogue." Historical Studies in the Physical Sciences 2 (1970): 1-39. Roger H. Stuewer, "On Compton's Research Program." In R. S. Cohen et al. (ed.), Essays in Memory of Imre Lakatos. Dordrecht: D. Reidel, 1976. Pp. 617-633.
B Arthur H. Compton, "A Quantum Theory of the Scattering of X-rays by Light Elements." Physical Review 21 (1923): 483-502. Reprinted in Spencer R. Weart (ed.), Selected Papers of Great American Physicists. New York: American Institute of Physics, 1976. Pp. 152-171.
C Roger H. Stuewer, The Compton Effect: Turning Point in Physics. New York: Science History Publications, 1975.
Week 10: Matrix and Wave Mechanics

Kragh 1999, Ch. 11, pp. 155-173 ("Quantum Jumps").

Segrè 1980, Ch. 8, pp. 149-174 ("A True Quantum Mechanics at Last"). Van der Waerden 1968, pp. 1-59 ("Introduction").

B Van der Waerden 1968, (Translations of) original papers by Heisenberg, Born, Jordan, Pauli and Dirac (selection TBA). Linda Wessels, "Schridinger's Route to Wave Mechanics." Studies in the History and Philosophy of Science 10 (1977): 311-340.

Gunther Ludwig, Wave Mechanics. Oxford: Pergamon, 1968. Translations of original papers by De Broglie and Schrödinger.

Max Jammer, The Conceptual Development of Quantum Mechanics. Los Angeles: Tomash Publishers; New York: American Institute of Physics, 1989 (originally published 1966).

Walter Moore, Schrödinger. Life and Thought. Cambridge: Cambridge University Press, 1989.

David C. Cassidy, Uncertainty. The Life and Science of Werner Heisenberg. New York: Freeman, 1992.

Helge Kragh, Dirac: A Scientific Biography. Cambridge: Cambridge University Press, 1990.

Week 11: The Interpretation of Quantum Mechanics: EPR

Kragh 1999, Ch. 14, pp. 206-217 ("Philosophical Implications of Quantum Mechanics").

David Z. Albert, Quantum Mechanics and Experience. Cambridge: Harvard University Press, 1992. Ch. 1, pp. 1-16 ("Superposition")

Michel Janssen, Notes on QM and EPR ‹ la Albert. Handout for course Einstein for Everyone.

B Albert Einstein, Boris Podolsky, and Nathan Rosen, "Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?" Physical Review 47 (1935): 777-780.

Mara Beller, Quantum Dialogue. The Making of a Revolution. Chicago: University of Chicago Press, 1999.

Richard A. Healey and Geoffrey Hellman (eds.), Quantum Measurement: Beyond Paradox. Minnesota Studies in the Philosophy of Science XVII. Minneapolis: University of Minnesota Press, 1998.

John A. Wheeler and Wojciech H. Zurek (eds.). Quantum Theory and Measurement. Princeton: Princeton University Press, 1983.

James T. Cushing and Ernan McMullin (eds.), Philosophical Consequences of Quantum Theory. Reflections on Bell's Theorem. Notre Dame: University of Notre Dame Press, 1989.

James T. Cushing, Philosophical Concepts in Physics. The Historical Relation Between Philosophy and Scientific Theories. Cambridge: Cambridge University Press, 1998. Parts VII-VIII, pp. 271-355 ("The Quantum World and the Completeness of Quantum Mechanics," "Some Philosophical Lessons from Quantum Mechanics").

Christoph Lehner, Quantum Mechanics and Reality. An Interpretation of Everett's Theory. Ph.D. Thesis, Stanford University, 1997.

Week 12: Einstein's Path to General Relativity

John Stachel, "History of Relativity." In Laurie M. Brown et al. (eds.) Twentieth Century Physics. 3 Vols. New York: American Institute of Physics, 1995. Vol. 1, pp. 249-356. Only read sec. 4.1, pp. 249-254 ("Introduction") and sec. 4.3, pp. 286-320 ("The General Theory of Relativity").

Robert Schulmann et al. (ed.), The Collected Papers of Albert Einstein. Vol. 8. The Berlin Years: Correspondence, 1914-1918. Princeton: Princeton University Press, 1989. Editorial note: "The Einstein-De Sitter-Weyl- Klein Debate," pp. 351-357.

Albert Einstein, Relativity. The Special and the General Theory. (1916/1918) New York: Crown Publishers, 1952. Part II, pp. 59-104 ("The General Theory of Relativity") and part III, p. 105-114 ("Considerations on the Universe as a Whole").


Albert Einstein, "The Foundation of the General Theory of Relativity" (1916). Einstein et al. 1952, pp. 111-164.

Albert Einstein, "Cosmological Considerations on the General Theory of Relativity." (1917) Einstein et al. 1952, pp. 177-188.

John Norton, "How Einstein Found His Field Equations: 1912-1915." Historical Studies in the Physical Sciences. 14 (1984): 253-316. Reprinted in Don Howard and John Stachel (eds.), Einstein and the History of General Relativity (Einstein Studies, Vol. 1). Boston: Birkh-user, 1989. Pp. 101-159.

Jürgen Renn, Tilman Sauer, Michel Janssen, John Norton, John Stachel, The Genesis of General Relativity: Documents and Interpretation. Vol. 1. General Relativity in the Making: Einstein's Zurich Notebook. Dordrecht: Kluwer, 2001. (I can provide you with current drafts.)

John Earman, World Enough and Space-time Absolute versus Relational Theories of Space and Time. Cambridge: The MIT Press, 1989.

Week 13: Cosmology and Inflation

Kragh 1999, Ch. 23. pp. 349-365 ("Cosmology and the Renaissance of Relativity").

Alan H. Guth, "Inflationary Universe." In Norriss S. Hetherington (ed.), Encyclopaedia of Cosmology. New York and London: Garland, 1993. Pp. 301-322.

Michael Turner, "Cosmology Solved? Quite Possibly!" Publications of the Astronomical Society of the Pacific 111 (1999): 264-273.


Alan Lightman, Ancient Light. Our Changing View of the Universe. Cambridge: Harvard University Press, 1991.

Alan H. Guth, The Inflationary Universe. The Quest for a New Theory of Cosmic Origins. Reading: Addison-Wesley, 1997.

Kip Thorne, Black Holes and Time Warps. Einstein's Outrageous Legacy. New York, London: Norton, 1994.

Week 14: Nuclear Physics

Kragh 1999, Ch. 12, pp. 174-189 ("The Rise of Nuclear Physics").

Segrè 1980, Ch. 9, pp. 175-199 ("The Wonder Year 1932: Neutron, Positron, Deuterium, and Other Discoveries").


Roger Stuewer, "The Nuclear Electron Hypothesis." William R. Shea (ed.), Otto Hahn and the Rise of Nuclear Physics. Dordrecht: D. Reidel, 1983. Pp. 19-67.

———, "Gamow's Theory of Alpha-Decay." In: E. Ullmann-Margalit (ed.), The Kaleidoscope of Science. Dordrecht: D. Reidel, 1986. Pp. 147-186.

———, "The Origin of the Liquid Drop Model and the Interpretation of Nuclear Fission." Perspectives on Science 2 (1994): 76-129.

C Roger Stuewer (ed.), Nuclear Physics in Retrospect: Proceedings of a Symposium on the 1930s. Minneapolis: University of Minnesota Press.
Week 15: High-Energy Physics

Kragh 1999, Chs. 21-22, pp. 312-348 ("Particle Discoveries," "Fundamental Theories").

Segrè 1980, Ch. 11-13, pp. 223-289 ("E. O. Lawrence and Particle Accelerators," "Beyond the Nucleus," "New Branches from the Old Stump").

Pickering 1984. Selections focusing on neutral currents (TBA)


Peter Galison, How Experiments End. Chicago and London: University of Chicago Press. 1987. Ch. 4, pp. 135-241 ("Ending a High-Energy Physics Experiment").

———, Image and Logic. A Material Culture of Microphysics. Chicago and London: University of Chicago Press. 1997.

Robert P. Crease and Charles C. Mann, The Second Creation. Makers of the Revolution in 20th century Physics. New York: Collier Books, MacMillan Publishing Company, 1986.

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