Re: [Phys-l] A demo for biologists?

[ludwik kowalski <kowalskil@mail.montclair.edu>]

Dear Bernard,

What is CFL? What is this "it" that you tried? Did you use an  
interferometer? If not then why do you think that fringes have  
anything to do with your saran wrap?

Ludwik, who is often confused by telegraphic style, and by acronyms  
with which he is not familiar.


On May 17, 2009, at 12:31 AM, Bernard Cleyet wrote:

> Aaagh -- not a microscope,  microscope slides.   I just tried it w/
> saran wrap.  (0.0003"** = ~ 7.6 microns)   This is ~ 13 wavelength.
> So ~ 26*** fringes over very ~ 3"  (v.~ 7 cm);  easily counted w/ a
> magnifying glass, or unaided if equi-spaced.  Won't be as the glass
> isn't stiff.
>
> I didn't count them, as I was hand holding it and the beam was not
> wide enuff.  I also saw them (multicolored) with a CFL.  Using a CFL
> and a green filter would be good.  A kitchen physicist would use
> green food coloring in a glass of water?
>
> ** Measured with a 0.0001" X 0.050"  Mitutoyo Dial Thickness Gauge.
> ***Assuming no Sr. moment.
>
> bc, occasionally a kitchen physicist; currently a coffee table
> physicist.
>
>
> On 2009, May 16, , at 11:57, ludwik kowalski wrote:
>
> > Dear Bernard,
> > I would do this, If I had a microscope at home. And using a sensitive
> > scale, if I had it, I would determine the thickness in terms
> > milligrams per square centimeter. Converting to microns would be
> > trivial if density were known. For a rough estimate, as in this case,
> > I would assume that the density is 1 g/cm^3.
> >
> > On May 16, 2009, at 2:36 PM, Bernard Cleyet wrote:
> >
> > > > The thickness was probably several
> > > > microns (I have nothing to measure the thickness at home).
> > >
> > >
> > > No!  You do.   place a piece of it at the end of two microscope
> > > slides so tother ends are in contact illuminate the slides w/ your
> > > LASER from far away and count the FECO.
> >
> >
> > - - - - - - - - - - - - - -
> > Ludwik Kowalski, a retired physics teacher and an amateur journalist.
> > Updated links  to publications and reviews are at:
> >
> > http://csam.montclair.edu/~kowalski/cf/   http://csam.montclair.edu/
> > ~kowalski/my_opeds.html
> >    http://csam.montclair.edu/~kowalski/revcom.html
> >
> > Also an ESSAY ON ECONOMICS at: http://csam.montclair.edu/~kowalski/
> > economy/essay9.html
> >
> >
> >
> >
> >
> >
> >
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- - - - - - - - - - - - - -
Ludwik Kowalski, a retired physics teacher and an amateur journalist.  
Updated links  to publications and reviews are at:

http://csam.montclair.edu/~kowalski/cf/   http://csam.montclair.edu/~kowalski/my_opeds.html 
   http://csam.montclair.edu/~kowalski/revcom.html

Also an ESSAY ON ECONOMICS at: http://csam.montclair.edu/~kowalski/economy/essay9.html