Physics 370 - Experimental Physics

Spring 2008, Room 338 Lightsey Center
Dr. Jeff Wragg   Office: 203B Bell Bldg.
Lab phone: 953-7374       Emergency phone: 953-5611      Access phone: 953-5609
email me Or send me a web-based email


Contents

Reference Material

Topics in Experimental Physics

Elements of a Good Experiment

Equipment review and introductions

Computer Use

Data Analysis

Writing a Paper

Ethics

General

There is no formal text for this course, rather it is a compilation of notes, handouts, and web resource materials. It is absolutely vital that you take comprehensive notes during the class. This semester is your opportunity to develop your physical intuition in the context of investigating a problem. You will get to formally state the problem, design and construct the investigation, analyze the data, draw appropriate conclusions and communicate the results. In all respects a more polished performance is required of you in this class than you have had to demonstrate in the past. This course represents a transition for you, from student to professional. You need to develop a professional sense of responsibility for the work you produce, and for the process of producing it. Much of the evaluation of your work (by me) is from a professional perspective. Think of yourselves as doing work for pay, and I am the boss. Don't turn in a student product, turn in a professional one.

Please communicate your questions, comments, and problems to me. I am pleased to see you any time you can drop in. Please leave me a note if you can't find me.

It is your responsibility to learn--to do the work using available resources, taking responsibility for finding the knowledge and equipment you need. You get to work in groups and alone. Take this opportunity to show to everyone that you can handle the responsibility. Historically, the biggest problem encountered by students in this course is poor time management. You are given some freedom to schedule your assault on the problem--don't abuse this freedom.

Be courteous to others. We have limited space and equipment, so don't expect to set up an experiment and have sole use of the equipment and space for more than a couple of days. You may need to coordinate with your classmates for access to some equipment. There may be times when courtesy should be extended with regard to opening the door and turning on lights. You are expected to put equipment away and otherwise keep the experiment areas clean and tidy.

Preparation for the Course
Modern Physics (phys330) is a prerequisite for this course. You will need to maintain a working knowledge of the physics and mathematics at the level of physics 201, 202 and 330. Laboratory experiences in physics 201-202 are a valuable knowledge and experience base for this course. Review your laboratory experience. Look over old reports to identify skills you need. Of course by now you should have completed English 101/102. If you haven't, then don't take this course. Finish English first.

I also assume that you have computer skills, including email, using the web, word processing, Mathematica, spread sheets, and other generic, scientific computer tools. We will enhance your skills with all of these.

Structure
We will have formal classroom time, especially early in the semester. It is important that you apply your attention to these presentations as they will be vital to your experiments. Students will be required to pick a professional track-- physics, astronomy, or meteorology. While everyone does the same first experiment, there are computer, equipment and write-up differences between the professions.

There will be two phases to the course.

Groups
I may allow you to work in groups of up to three. You may not work with any specific individual on more than two of your experiments. I reserve the right to restrict your choice of partners, and I may even require you to work alone.

Goals


Objectives
You should be able to:

Absences & Tardiness
On the occasions we have formal classroom time you are responsible for the material presented. Contact a classmate for the notes.

Preparing to do an Experiment
There are several steps to take before you actually do an experiment.

Lab Notebooks
You will maintain a notebook of your lab experience. It is an up to date diary of your lab work. It should contain dates, names, times, equipment lists, diagrams, raw data, musings, ideas, sketches, casual observations... This is the basis for your lab report, which should contain nothing that isn't in the notebook, at least rudimentarily. It should be decipherable by your colleagues, but is intended to be a working document, not a finished product. I will examine these notebooks from time to time without notice. Here are some guidelines:

Lab Reports

Each student will submit their own report, even though you may do the experiment as a group. While you may work closely together, each student writes up their own report, in the appropriate format (i.e., using the LaTeX template suitable to their profession), and each student should be completely competent in the details of data manipulation and analysis. Reports are expected to meet the highest editorial and scientific standards. Pretend it is being submitted to a refereed journal for publication and that your job is on the line. The details of your format are dictated by those used in a journal you choose which is consistent with your career goals. The term "lab report" is somewhat of a misnomer, as you turn in a lab notebook, and your formal write-up is more of a journal submission format.

These formal reports are the focal point of your work. The experiment isn't worth doing unless its results are communicated to others. A generic, everything is OK, no significant errors, good layout, adequately conducted, reasonable conclusion lab will get you "B". Subtlety, insight, and cleverness can get you more. Lab reports are written up individually, even though experiments may be conducted as a group. It is inappropriate (i.e., it is considered academic dishonesty) to share your write-ups with others in the class, to pass them down to students in future classes, or to get them from previous classes.

Reports will ordinarily contain:

  1. An abstract of no more than 100 words. A concise summary of your experiment and the results.
  2. A brief introduction clearly stating the physical principles involved and the goal of the experiment.
  3. Background and references, historical and/or scientific (Do not make this extensive).
  4. Clear description of the procedures and an illustration of the experimental equipment.
  5. Relevant data, graphical &/or tabular. Do not include exhaustive raw data.
  6. Description of the analysis of the data, the result, the uncertainty, and comparisons with generally accepted results
  7. Conclusions: what can you say based on your experiment? How does your result relate to the goal of the experiment? Is the theory upheld by the experiment? Do not make this a personal commentary on the experience you had doing the lab.
  8. References

The Checklist-- Pitfalls, Tips, and Hints....

  1. Abstract: comprehensive, informative, and includes the answer.
  2. Ask yourself: "What is the purpose of this section." "What is the purpose of this paragraph." "What is the purpose of this sentence."
  3. The report should be written at the appropriate technical level--for your peers.
  4. Keep in contact with me during the experiment. Brainstorm with me. The more you tell me what you are doing the more likely I can save you some time.
  5. Tables and figures are usually best placed as soon as feasible after they are referred to in the text. Note that LaTeX has its own way of deciding where to put them, but you do have some influence over it.
  6. Start the write-up early in the experiment. It will help you decide what data you need, and may suggest extra experimenting.
  7. The word "then" is often misused/overused.
  8. Lead in to equations properly. Look in books and technical papers to see how one leads into an equation. Also, you must define all variables when they first appear.
  9. Use superscripts, subscripts and other typography appropriately.
  10. Use symbols, abbreviations, and language that are consistent with your professional identity.
  11. Include an answer and uncertainty, with appropriate significant figures, and units.
  12. When possible, compare your result with accepted results, and give a reference
  13. It is probably best to write in the past tense.
  14. Figures-- Keep them simple, make them schematic rather than artistic. They should be numbered and include a useful caption.
  15. Graphs-- Should be simple, but complete, with axes labeled, and data points, and fitted functions distinct from one another. A figure should be numbered and include a descriptive caption.
    16. Things NOT to include--
  16. Do not include details we don't care about, e.g., "...on Tuesday John measured...", the reader generally doesn't care about the day or the name of the person. Or trivial details about instruments such as " We used detector number 3 ".
  17. Do not show trivial calculations. There is no need to define what an average is and show us how to calculate it.
  18. Don't use contractions.
  19. Avoid "cute" words, i.e., ones you feel should be enclosed in quotes.
  20. Do not make subjective statements such as "our results are good." Be objective, and let the reader judge you.
  21. Do not give a list of materials/equipment.
  22. Do not put references in the abstract.

The editorial guidelines used by the American Physical Society or American Astronomical Society will generally be followed unless you convince me that you should follow the guidelines of another organization. If your career goals and academic path are consistent with your case it will likely be fine with me. See example papers in journals such as Physical Review, or check out their online style guide, or the Astrophysics style guide

Report Grading Criteria

In addition to the guidelines above the following will be considered when assigning a grade to your report.

Oral Presentation

You will make oral presentations in several ways. On occasion you will be asked to give a 1-2 minute status report on your current experiment. This will likely be without notice. After the second experiment you will give a five minute semi-formal presentation (using PowerPoint or other suitable presentation aid) on your second experiment. Finally, you will give an eight minute formal presentation, probably, but not necessarily, on your third experiment.

The formal presentation will be given during the final exam period for our class. The talks follow a standard presentation format used at scientific meetings. The talks will be 8 minutes long (+/- 1 min), and use suitable, professional-quality visual aids.

Talk Details

Due Dates (subject to change)

The above due dates are subject to change. Late assignments may be accepted (at my whim), but will ordinarily be penalized, more so each day they are late.

Grades
The accumulation of points is as follows. We do three experiments. For experiments one and two you submit an original lab report, then we do some editing, and you submit a revised version. The original and its revision are each graded, and carry the same weight. The third experiment is a one-shot effort--no revision. In the overall grading scheme the first experiment carries a weight of 2, the second a weight of 4, and the third a weight of 5.

Lab reports70%
Lab Notebook15%
Quizzes and proficiency exercises10%
Oral Presentation5%
Total 100% of course grade

Updated: 24 Apr 08