Spring 2001

Physics 516 / 616 - Intermediate / Advanced Physics Laboratory
General Information

The Purpose of the Course

The purpose of the course is threefold:

  1. To help you extend your breadth and depth of basic physics knowledge.
  2. To help you learn how to plan and conduct a good experiment.
  3. To help you learn how to correctly analyze data and prepare a good report.

This course emphasizes independent work and critical reasoning. In this course, a student normally completes three experiments in various areas of physics. In some of these areas you will have had no formal classroom training. This course allows you to explore such areas. As it is important that the instructor be able to fully evaluate your work, as well as be able to assist you in difficult portions of your experiments, we require that you keep a record of your work in a laboratory notebook and do your lab work in the scheduled hours (12:30-3:30 PM Tuesday and Thursday). Additional hours may be scheduled, if you require.

In addition to making measurements, you must be able to evaluate your experiment - that is, you must be able to assign an uncertainty to the quantity you have measured. Textbooks discussing experimental methods, errors, error propagation, etc., include:

These book are all available in the Physics 616 library. You are expected to perform a detailed statistical analysis of the data in your experiments using the procedures outlined in these texts. The final step in any experiment is preparing a report which includes what you did, how you did it and the results of your efforts. Consequently, a write-up on each experiment is required.

The Experiments

Experiments are available in different areas of physics with varying degrees of difficulty. Thus a match between your background and interests and experiments can usually be effected. You will choose an experiment in consultation with the instructor and be given the necessary equipment; it is yours until you complete the experimental phase of your work. Each experiment has a lab sheetthat outlines the general goals of the experiment and lists a number of references to information available in the laboratory (special notes, books, film loops, instrumentation manuals) and in the library. Using these, you are expected to acquire the proper background to do the experiment - this should be done before you come to the laboratory. You goal should be to understand the general nature of the experiment, determine the experimental objectives, and organize a procedure for making the measurements. These should all be written in your laboratory notebook. You should discuss these plans with the instructor before making your measurements - particularly if the equipment you use is of a fragile or dangerous nature. These procedures may be modified as you gain knowledge and experience.

The planning of an experiment includes estimates of the values of the quantities to be measured, and a determination of what places the ultimate limit on the precision of your measurement. When you begin the experiment you should make a rough preliminary data run over the entire range of appropriate variables. This will allow you to gain familiarity with your equipment, point out unexpected pitfalls in the experiment, and determine if the apparatus can in fact be used, as set up, over the entire range you anticipate. Plot a graph of the measurements as you make them to make sure that the apparatus is behaving in a reasonable manner. After a preliminary run, you should be able to proceed directly to your final set of measurements.

The apparatus you use may involve expensive and/or hard-to-replace equipment. Be sure you understand its pitfalls before using it (i.e., read the instruction manual). Consult with the instructor if there is any apparatus you find unfamiliar. The apparatus may also have some "bugs" in it, or develop ailing symptoms unexpectedly while the experiment is in progress. You should be alert for these possibilities and, as far as practical, solve them yourself. This is an important part of the learning process. Being sure that your equipment is performing correctly is a vital part of any experiment and hence the ability to discern faulty operation is an important part of your training. Should you believe any piece of equipment is not functioning properly, discuss the problem with the instructor ASAP so repairs or replacements can be provided as necessary. The successful conduct of any experiment calls for the constant exercise of good judgment. In the course of your work, you will find points that puzzle - or interest - you but which are outside the main point of the experiment. So that you do not get sidetracked, complete the main objectives of your experiment and then, if time permits, explore these side issues.

When you complete the data taking part of your experiment, see the instructor to be certain you have all the data that is necessary. The instructor may ask to see your laboratory notebook. The instructor may ask you to do more work.