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

[Bernard Cleyet <bernardcleyet@redshift.com>]

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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