PHYSICS III: Modern Essentials Carnegie Mellon University 33.211, 33.213 Department of Physics Fall, 2003 Version 1.2 Instructor: Professor Reinhard Schumacher, Wean Hall 8406 412-268-5177 office 243-2279 home email: schumacher@cmu.edu Lectures: Recitation: Monday, Tuesday, Wednesday, 9:30 am - 10:20 am, Friday 9:30 am - 10:20 am, Doherty Hall A310 Doherty Hall A310 Required Texts: Spacetime Physics, 2nd Ed., E. F. Taylor and J. A. Wheeler, Freeman (1992); (used for both 33.211 and 33.213) Modern Physics, 4th Ed., P. A. Tipler & R. A. Llewellyn, Freeman (2003); (used for 33.211 only) Goals of the Course: This course is required for third-semester students of physics, but is open to anyone who wants to become familiar with some of the key concepts underlying modern physics. We will study Special Relativity and Quantum Physics, which were developed starting 50 to 100 years ago, and upon which much of present-day physics are built. The first seven weeks of the course (mini-course 33.213) will cover Special Relativity. We will cover relativistic kinematics and dynamics, but not electricity and magnetism. The mathematics involved is simple but the concepts challenge our every-day intuition. The second part of the course will take a broad look at quantum phenomena. Again, while the concepts are challenging the mathematical formalism will be minimal. Nevertheless, the course will be quantitative, involving the algebraic and numerical solution of many problems. The class should therefore improve your skills in thinking through and solving interesting physics problems. It is definitely possible to develop reliable intuition for relativistic and quantum physics, and this course should get you off to a good start. The course will prepare you for later classes you may take in electricity and magnetism and in quantum theory. It leads into the Quantum Physics course (33.234), which will begin with a more formal treatment of quantum mechanics. 1 Web-sites: Going to http://info.phys.cmu.edu/resources/course_pages.asp and clicking on 33-211 will get you to the web-site for this course. It lists office hours, the schedule of classes and exams, the weekly homework assignments, previous exams (some with solutions), interesting physics links, and news concerning the course. Please bookmark this site and check it often. The Tipler textbook has its own accompanying web-site at www.whfreeman.com/tiplermodernphysics4e/. Please try it out and let me know of any problems you encounter. Quizzes, Exams, & Grades: There will be unannounced short quizzes, usually based on the current assignment or on examples from the previous lectures. The quizzes may be given at the beginning of the lectures so be on time and be prepared. There will be three one-hour exams during the semester, worth 100 points each, and a three-hour final exam worth 400 points. The exams will be given during regular class times in the usual classroom. They will be closed-book exams with no notes permitted. No make-up exams will given. If you cannot take an exam for any reason, tell the instructor beforehand, but very few excuses will be accepted for missing an exam. The weighting factors which will be used in determining the course grades are: Three hour exams 3x10% = 30% Final exam = 40% Quizzes = 15% Homework = 15% Letter grades will be computed from your overall numerical score at mid-term and at the end of the semester. The final letter grades for the course will be determined by the following approximate scale: A > 87%; B 75-87%; C 60-75%; D 50-60%; R <50%. In borderline cases, based on the instructor's perception of your work, we will consider diligent lecture attendance, class participation, and consistency of performance throughout the semester. Assignments: There will be weekly homework assignments, consisting of assigned readings and problems to be solved. Doing the written assignments, i.e. problem solving, is the single most important tool for learning the course material. You should feel free to discuss the homework problems with your associates; in fact, it often helps to work in small groups. You should write out the solutions on your own, because you need to fully understand the material yourself. Since 2 this is a ten-unit course and we meet in class for four hours per week, plan to spend about six hour per week outside of class. If your background is weak in algebra or in classical physics, you will need to spend more time. If you can't solve a problem within a reasonable time, say 30 minutes, ask the instructor or a fellow student for help. Also, start immediately on new assignments, so that you have time to ask questions and to revisit things you don't grasp at first. Generally, homework dealing with the previous week's concepts will be collected on Tuesdays at the beginning of the lecture. Written solutions will be provided on the course website. A randomly selected subset of the problems will be graded, and all problems will be checked to see if you made a serious effort to solve them. Since you won't know in advance which ones these are, do all problems fully. The problems indicate the minimum level of achievement expected of all students. Please always go over your returned work and the solutions, simply because they will not be graded in detail, and because the tests will be similar to the previous homework problems. Turn in all the assignments on time! 20% per day will be deducted for late work, and zero credit will be given after solutions are posted. Again, if you get stuck on problems, feel free to come to my office for help. I am usually available for short discussions, either after class or in my office. You can call (8-5177) to be certain I am available before stopping by, but you are free to drop in. For longer talks we can set a time to meet, as needed. In the evenings you may call my home number before 10pm. 3 Course Schedule: Approximate Weeks The tentative schedule for the semester: Topics Approximate Dates Special Relativity 1 2 3 4 5 6 Taylor & Wheeler Introduction 8 - 25 Invariant Spacetime Intervals 26 Chapter 1 Frames of Reference 27 Chapter 2 Observers & Test Particles 9-2 Invariants, Simultaneity 3 Length Contraction/ Time Dilation 8 Velocity Addition 9 Lorentz Transformation 10, 15 Chapter ST Coordinatizing Spacetime 16, 17 Chapter 5 The Twin "Paradox" 22 Chapter 4 Space-like and Time-like Intervals 23 Chapter 6 Invariants; 4-vectors 24, 29 Chapter 7 EXAM I 6 7 Assigned Reading Chapter 3 Friday, September 26 Conservation Laws 30, 10 - 1 Using the Conservation Laws 6 Creation/Annihilation of Particles 7 Gravity: Curved Spacetime 8 4 Chapter 8 Chapter 9 Quantum Phenomena 8 9 Tipler & Llewellyn Particles and Fields 13 Quantization of Charge and Energy 14 Blackbody Radiation 15, 21 Light Quantization: Photoelectric Effect 22 EXAM II 10 11 12 13 15 3-3 Friday, October 24 X-rays 27 Compton Effect 28 Atomic Spectra 29 The Atomic Nucleus 3 The Bohr Model of Hydrogen 4, 5 4-3 X Ray Spectra 10 4-4, 4-5 The Franck-Hertz Experiment 11 4-6 The Wave Nature of Particles 12, 17, 18 5-1, 5-2, 5-3 Wave Packets 19 EXAM III 14 3-1, 3-2 3-4 4-1, 4-2 Friday, November 21 Wave Particle Duality 24 Probability 25 Uncertainty 12 - 1, 2 The Schrödinger Equation 3, 5 FINAL EXAM, time and place T.B.A. (3 hours) Next Step: The Quantum Physics course (33.234)! 5 5-4 thru 5-7 Chap. 6...