Physics 3170/3180 Syllabus
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:
- 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.
- 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.
- 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).
.
The body of the report will normally contain the following elements.
The headings may be included explicitly, or omitted, or grouped
differently.
- 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).
- Apparatus and Procedure. Describe the apparatus, using
diagrams
and identifying the specific pieces of equipment. Explain exactly what
measurements you made.
- 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.
- 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.
- 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.
- Bibliography. See above.
- 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.
- G.L. Squires, Practical Physics (Cambridge, 1987). This
brief
book
is an excellent guide to what we will expect in lab reports.
- D.C. Baird, Experimentation, 2nd ed. (Prentice Hall,
1988).
Similar
first edition is still good.
- P.R. Bevington, Data Reduction... (McGraw-Hill, 1969).
Valuable
reference for practical error analysis and curve fitting. Somewhat
esoteric
on the philosophic underpinnings.
- L. Lyons, Data Analysis...(Cambridge, 1991).