[Phys-L] Re: Lab Reports (was Human Error)

[Bernard Cleyet <anngeorg@PACBELL.NET>]

We  (UC Santa Cruz) also use the Pasco, but the first one (pre-1980).
It was not the most labour intensive or difficult experiment. The more
were EPR (using synchronous detection) and Brownian motion using an HP
spectrum analyzer.  Of the seventeen experiments I maintained
(instructed the TAs and new faculty, and filled in TA) only eight are
now offered including only the Millikan (of the above).

excerpts (paraphrased) from the manual:

----------

Min. data:  five rise and fall times w/ five different charges


The q (electron) has usually been systematically ~ 10% low even tho the
statistical uncertainty has been ~ 2%.  [R. Mackey (Fall '92) obtained
only a 2% error using THIRTEEN DROPS AND 300 TRANSITS.]

Another group by analyzing their data daily found a statistically
significant difference in the daily means.  Bridges (Lab. committee
chair) suggests it is due to varying humidity.

------------

[Hint; hint.]


I discovered an inexpensive sensitive CCD camera and introduced its use
in the Zeeman effect xpt (also dropped).  A student worker [The best! of
at least 20.] suggested it's use w/ the Pasco.

bc

Not BTW, it's a five unit, one quarter course; equal to all the others.
  Some faculty, and I, consider it the most important course
(undergrad.) the Dept. offers.




Michael Edmiston wrote:
> David Marx reports the student comment... "Subequent conversations with
> the other experimenters revealed that they would rather be wrong than go
> into the lab to take more data using the correct method.  So, the
> results reported here will likely be wrong."
>
> We also have the Pasco Millikan system, which is quite a nice system.
> One of the things I like about this experiment is that it is very
> frustrating and helps students understand what Millikan's assistants
> went through, for a rather long period of time.
>
> Every time I suggested that maybe they should take more data, it was
> like I was sending them to the torture chamber.  I think just about
> every student thinks it is the most difficult experiment they have done.
>
> I heard comments similar to what David heard.  I even heard... "If we
> all boycotted this lab, you wouldn't flunk us all would you?"  I said,
> "Go ahead.  Make my day.  Nothing is easier to grade than nothing."
>
>
> Michael D. Edmiston, Ph.D.
> Professor of Physics and Chemistry
> Bluffton University
> Bluffton, OH 45817
> (419)-358-3270
> edmiston@bluffton.edu
_______________________________________________
Phys-L mailing list
Phys-L@electron.physics.buffalo.edu
https://www.physics.buffalo.edu/mailman/listinfo/phys-l