Reading Memos
For the waves topic, there will be no blanks to fill in on the notes. Instead, as well as printing the notes for each lesson, your homework is to do a reading memo. Below I describe how to do them, which I learnt from Sanjoy Mahajan, a first rate teacher of physics. Please turn them in at the beginning of the lesson for which the reading is to be completed.
These memos are not optional, and must be completed for each lesson. We shan't be reading over the notes in lessons, so if you don't read them ahead of time for yourself you will be lost, which is not good for you or for the class. Also, by doing a reading memo you'll read attentively and learn more.
Why am I so keen that you read the material before the lessons? The short answer is that it's a much better use of class time for us to discuss physics rather than for me to present material aloud for the first time. Here is a longer answer (1.6MB PDF article), a classic talk by Robert Morrison on 'The lecture system in teaching science.'
Students!
[Text below borrowed almost verbatim from Edwin F. Taylor, "Guest comment: Only the student knows", American Journal of Physics 60(3):201-202 (March 1992).]
I have a problem with which only you can help me. I have been writing this textbook, on and off, for too many years. Over that time I have become accustomed to lying and approximating, and I no longer see what is wrong with the text. Only you, coming fresh to the subject, can recognize where the text fails to help your understanding. In this you are a world-class expert! Will you help?
As you read the text, please have a blank sheet of paper next to you. Note down difficulties as they appear, with text page number. If you cannot figure out what is wrong, tell me that too! If something later clears things up, just add that to the comments. Do not erase anything or cross it off; both entries are useful. At the end of each chapter, note down general difficulties that you have and questions that you would like answered. Do not revise or recopy your notes; it is very important that they be spontaneous, written down at the very minute you are reading.
Here is the right attitude: If you are not understanding something, it is my fault. Help me pinpoint where the text falls short.
Turn in the notes on each chapter on the day that the reading assignment is to be completed. I shall respond individually to each reading memo (don't forget to put your name on it!).
Parable of the blind carpenter.
I am like a carpenter who has spent years building a house. During that time the carpenter has gradually gone blind, now cannot see the house at all, and must rely on the occupants of the house to report what is wrong: "We need more cupboards in the kitchen", or "Water is leaking into the bedroom." Even though blind, the carpenter is still a competent worker and can fix most things, even some things that the occupants do not fully understand, such as exactly where the roof leaks. But the blind carpenter cannot fix things without being alerted by the occupants.
Will you help me finish this house? Thank you.
How reading memos help you
The previous section explained how reading memos help me. Here's how they help you. First, you practise reading a textbook. When you leave school to go to university or elsewhere, the world is large and there are many lifetimes of fascinating ideas to learn. If you can learn from books, you have mastered a lifelong skill.
Second, and related to the first point, by reading with attention and with a questioning attitude, you participate in your own learning. That skill too will be useful for your whole life.
Third, reading memos reverse the normal teacher—student hierarchy. For a contrast, think about problem sets. If you cannot solve a problem, you might feel incapable and might become unhappy. I felt that way when I was a student. With a reading memo, when you do not understand where an equation came from, or follow an argument, you have found a problem in the notes. As it says in the previous section, in Edwin Taylor's words, with reading memos you are a world-class expert.
Use reading memos as a way to practice reading technical material, to formulate questions, and to feel like, nay, to be, an expert.
What is a reasonable effort?
For a reasonable effort on a reading memo, one comment is not enough unless it's unusual in its thoughtfulness. Ten comments is more than needed (but feel free to make as many as you are inspired to make). Hence, somewhere between 1 and 10—call it a 'few'—is about right (here, 'few' doesn’t literally mean 3).
