Physics 3170/3180 Syllabus

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Procedures:

Work with one lab partner, normally the same one throughout the semester. Obtain one bound lab notebook for each group and record a journal of your work in lab, including brief descriptions of the apparatus and the procedures, and any data recorded manually, clearly labeled.  If you are recording data in computer files, keep a  complete index to the files in your journal.  Likewise, include an index to any computer files used for data analysis. Plan to include preliminary graphs of your results, which can be used to judge the adequacy of your data before you shut down the experiment and go home to write the report.

Each partner should make a photo copy of the relevant journal pages for use in writing the report, and this copy should be turned in with the report.
 

Experiments:

You will do five experiments, selected in consultation with the instructors. Criteria for selection of experiments, in addition to your interest, include a balance of longer and shorter (or more difficult/easier) experiments, a reasonable representation of different areas of physics, a preference for experiments not previously done this semester, and balancing the work load for the instructors  who are responsible for particular experiments.

The gamma experiment is a required experiment.  The intent is that you acquire some familiarity with the special techniques used in nuclear physics.

When you have nearly completed an experiment (and plotted preliminary graphs of the data), meet  with the appropriate instructor to sit down for about 5 minutes and go over your notebook. You should be prepared to give a brief oral commentary on what you did, what the results were, and what conclusions can be drawn. Pay attention to suggestions the instructor may have on analysis or interpretation you should include in your report. Then (A) do any remaining work suggested on the experiment;  (B) write your report / begin the next experiment.

Choose  your next experiment and consult the appropriate instructor by the end of preceding lab, and do enough reading so that you know what it is all about before the first lab period on the new experiment. (Check with the instructor somewhat in advance about availability and suitability of the experiments you are considering.)
 
Estimate the precision of all measurements (i.e., error analysis)!

Reports:

The report is due one week from the next lab period after you finish the experiment.  For the fourth experiment the detailed written report will be replaced by an oral presentation to the class, near the end of the semester..

The most important thing the instructor will look for is what qualitative, and especially what quantitative, information you are able to extract from your data. Physics content will be graded on a scale of 5.0 to 1.0, corresponding roughly to A+ to D-.    Late penalties of 0.3 points/week may be assessed.

The Department recognizes the importance of the ability to write clearly, so the organization and writing of the reports, in addition to the technical content, will affect your grade  If you plan to use the course to satisfy the second writing requirement, consult G. Hess early in the semester.
 

Format for Lab Reports:

Most lab reports will fit in a fairly standard format, which is outlined below. It is up to you to decide how closely to follow this or when a different arrangement may result in a clearer report. However, the following few elements are required in this course:
 
  1. An ABSTRACT should appear on the title page. It is a concise summary of what the reader will find in the paper. State in three of four sentences: "This is what we did. These are the main things we found."  You should use appropriate technical terms, leaving their definitions and explanations for the Introduction.
  2. The last page or two should be a BIBLIOGRAPHY. List all references works used, whether explicitly cited in the text or not. Use citations throughout the paper to acknowledge sources. These citations may be by number or by author, e.g. [1] or [Melissinos, p. 54]. Comments on the value to you of individual references are be useful, but optional.
  3. The text should tie everything together in a linear sequence. Therefore all Tables, Figures, and Graphs should be cited by number at an appropriate place in the text. You may number Graphs in a separate sequence from Figures (the later being sketches, diagrams, photographs, etc.) or they can all be treated as Figures in a single numbering sequence. Place Figures, Graphs, and Tables in the text as close as possible to where they are cited (rather than at the end of the report). They may, however, be on separate pages from the text; this is particularly convenient if revisions are necessary (for instance, of the text but not the figures).
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The body of the report will normally contain the following elements. The headings may be included explicitly, or omitted, or grouped differently.
 
  1. Introduction or Background. Say briefly what the experiment is all about: Give some historical context, but not many pages or long quotations. Outline theoretical results which will be needed, but omit intermediate steps of derivations; you don't have to tell everything you know. Be sure to define all terms appearing in formulas. Do not make this section too large a fraction of the report. (Theory could be a separate heading).
  2. Apparatus and Procedure. Describe the apparatus, using diagrams and identifying the specific pieces of equipment. Explain exactly what measurements you made.
  3. Experimental Data. Give a narrative, which cites data in tables and graphs. Remember: All figures and tables should be numbered, and should have captions, or at minimum, labels.
  4. Analysis. Compute from your data whatever quantities are most appropriate for making comparison with theory, or for extracting useful information. Where repetitive calculations are necessary, present one sample calculation to make the procedure clear. Be sure to include a precision analysis (i.e., "error" analysis), which starts from estimates of the uncertainties of the measured quantities and leads to an estimate of the precision in the final quantity derived [See any of References, below]. Remember that the crux of the report is how much you can get out of your measurements.
  5. Conclusions. State the main results, but omit vague generalities. List and discuss possible causes of any discrepancies between your experiment and theory or previous measurements; bring your estimate of precision into the discussion. You might suggest specific improvements of the experiment.
  6. Bibliography. See above.
  7. Abstract. (See above.) This is part of title page of the report, but it is a good idea to write it last, when you know exactly what you are summarizing.
Problems of organization can arise when the experiment has several parts (A, B,...). Do you describe all of the Procedure, then all of the Data, etc.; or do you do everything for part A, then everything for part B. etc. ("everything" being topics 1 to 5, or maybe 2 through 4). It is your job to find a satisfactory solution for the particular report.

It may be useful to model your reports on old Physical Review papers. Go back to about 1950, when they were not too condensed, and look at a few short experimental papers. Also see Squires, p.169-175. Include in your report photographs and chart records if you can get them away from your lab partner. Otherwise, photocopy.

The actual write-ups, and interpretive work done out of the lab, should be done individually. However it is difficult to set a rigid rule on how far partners should cooperate (it generally will be obvious to the grader how far they did cooperate) and for that reason reports are not pledged. You should be diligent in citing sources, both for the benefit of the reader who wants more information, and to acknowledge your debt to the work of others (i.e., to avoid plagiarism, whether out of intent to deceive or just laziness).

Reports are normally word-processed, at least the text; but neat handwriting is acceptable. Graphs are most conveniently done with a spreadsheet or graphics program, but can also be hand drawn. In either case, be sure that axes are labeled, with units, and each graph has a "Graph" or "Figure" number and a caption.
 

Revisions:

You may be required to rewrite reports if the writing is not satisfactory. This may involve problems of overall organization, coherence of paragraphs, use of complete sentences, dangling participles, felicity and precision of expression, and probably other things which grate on the instructor's sensibilities when he reads the report.

We ask that with your revision you return the previous version of the report (or what is left of it after you have stripped any figures or other pages reused in the new version).
 

References:

These are on Reserve for PHYS 318 or PHYS 221. They all describe treatment of "errors" (i.e., estimation of precision) and several offer advice on writing lab reports.
 
  1. G.L. Squires, Practical Physics (Cambridge, 1987). This brief book is an excellent guide to what we will expect in lab reports.
  2. D.C. Baird, Experimentation, 2nd ed. (Prentice Hall, 1988). Similar first edition is still good.
  3. P.R. Bevington, Data Reduction... (McGraw-Hill, 1969). Valuable reference for practical error analysis and curve fitting. Somewhat esoteric on the philosophic underpinnings.
  4. L. Lyons, Data Analysis...(Cambridge, 1991).

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