Topics: This course introduces the three central concepts of quantum mechanics, namely: (1) The outcome of an experiment cannot, in general, be predicted exactly; only the probability of the various outcomes can be found. (2) These probabilities arise through the interference of probability amplitudes. (3) Probability amplitudes can be associated with two experiments done far apart from each other ("entanglement"). The ideas are developed through the example of an intrinsically simple system ("spin 1/2"), which is treated with complete rigor and honesty.
Learning goals: Through your work in this course, you will
Teacher:
Dan Styer,
Wright 215, 440-775-8183, Dan.Styer@oberlin.edu
home telephone 440-281-1348 (9:00 am to 8:00 pm only).
Instructions for meeting with me are given under "Schedule" here.
Pronouns, nouns, adjectives, and the character of science: I don't care what pronouns you use when referring to me. Similarly, you may call me "Dan", or "Mr. Styer", or "Dr. Styer", or "Prof. Styer", whichever you find most comfortable. My personal preference, however, is that you call me "Dan". In this course I will present upsetting conclusions violently opposed to our common sense and common experience. (For example: That an atom might not have a position.) I hope you'll accept those conclusions because they are based on experimental evidence and on cogent, clear, fact-based reasoning -- experiments and reasoning that you or I or anyone else could execute. If you accept those conclusions instead because I have earned the right to put a fancy shingle in front of my name, my teaching will have been an abject failure.
Course web site: http://www.oberlin.edu/physics/dstyer/StrangeQ
Add-drop warning: If you wish to add or drop this course, you must do so via Banner self-service by 11:30 pm on Friday, 10 December 2021.
After the Christmas/New Year break this course will be taught in hybrid mode: I will continue to teach in the Dye Lecture Hall and if you're on campus you're welcome to come, but I will also Zoom those class sessions out over the Internet, so you don't need to attend in person.
Prerequisites: This course does not assume any background in science. High school level algebra and geometry will be used as needed without apology.
Text: D.F. Styer, The Strange World of Quantum Mechanics. You may purchase this text, or use this link.
Tutoring: Tutors are available for this course at no charge through Oberlin College's Center for Student Success. Contact them if you would like a tutor.
Format: This course is taught in person, but all work is submitted through Oberlin College's Blackboard course management system. Class meetings are on Tuesdays and Thursdays starting at 10:00 am. I begin each class by discussing questions raised at the previous class, then I go through some new material from the textbook, and finally I use the after-class reactions (see below) to gather questions to be answered at the following class. If you understand the material well enough from the reading, then you don't need to listen to the "new material" portion of the class.
Grading: This is a second-half-of-the-semester half course, graded on a Pass/No Pass basis. To receive credit, you must react to classes regularly and satisfactorily complete six assignments. There are no exams. (I find it impossible to think up exam questions for quantum mechanics at this level: the questions I come up with are either too hard or else not probing.)
How do you react to classes? By the end of the day (11:59 pm) each date when class meets, submit through Blackboard a sentence or two reacting to the state of your knowledge concerning quantum mechanics. I will use these reactions to plan the next class and the future path of this course. Your most useful reaction would be a specific question: for example, "What does it mean to say that an electron does not have a position?" Other possible reactions would be indications of general interest ("I'd like to learn more about entanglement.") or general questions about course material ("Why should I care about this stuff, anyway?"). There are 11 classes for this course, and you must react to at least 8 of them.
Assignments are due at the end of the day (11:59 pm) on each Thursday. They are administered and graded through Blackboard. You may rework an assignment as many times as you wish before the deadline. In working an assignment, you may consult any written or on-line material, or you may consult your friends (or your enemies!), but you must complete the assignment yourself . . . you may not, for example, copy answers from someone who has already done the assignment. I cannot accept late solutions. To pass the course, you must earn at least 60% on the assignments. (I appreciate that for some of the assignments you might be sick or for other reasons not at the peak of your abilities. That's why the 60% cutoff is set so low.)
The problem assignments are an opportunity for you hone your growing quantum-mechanical skills and knowledge by applying them to specific situations. It's easy to fool yourself into thinking that you understand quantum mechanics because you can follow the readings and grasp the outlines of the theory, whereas in fact understanding comes through knowing not just the theory, but also how to apply it. (Just as everyone wants a free, stable, unified, and democratic Korea, but no one seems to know how to get from where we are now to this laudable goal.)
This is the standard rule for intellectual discourse: When I write a research paper on quantum mechanics, I consult other materials, and before publication I always give the paper to a friend who suggests improvements. But I always cite the materials, I always acknowledge the friend, and I never copy an already published research paper.
You can track your grade status through the "My Grades" feature of Blackboard. It is easier for you to uncover your grade status than it is for me to, so if you write me asking for your grade I will not respond.
Course schedule:
Relevant readings from textbook The Strange World of Quantum Mechanics
are listed in square brackets.
| 30 November | Introduction [chap. 1] | |
| recommended: | Feynman on quantum mechanics (movie) | |
| [Movie available at http://www.youtube.com/watch?v=aAgcqgDc-YM.] | ||
| 2 December | Classical magnetic needles (demonstrations) [chap. 2] | |
| 7 December | Conundrum of projections; Repeated measurements [chaps. 3 and 4] | |
| 9 December | Probability [chap. 5] | |
| 14 December | Einstein-Podolsky-Rosen paradox [chap. 6] | |
| 16 December | Optical interference (demonstrations) [chap. 8] | |
| 21 December | Quantal interference [chap. 9] | |
| 4 January | Amplitudes [chaps. 10 and 11] | |
| 6 January | Quantum mechanics of a bouncing ball [chap. 14] | |
| 11 January | History of quantum mechanics | |
| 13 January | Summary |