Natural Science Forum / Physics / Optics / August 2007

I am interested in buying a Wild stereoscope of the M5/M7/M8 series.
Could someone discuss the different versions of these lines of scopes?
I recently saw a listing for a pair of Wild M7A and Wild M7S
stereoscopes...what are the differences between these scopes? Are

Hi, I'm new to lasers and just orderd a GVG-712 to play with.
If I like it then I'll order something a bit better and with
a blue laser.
Question. What is the smoke machine fluid? Is it something

I think I've gone and bought a multimode diode laser when I really
need a single mode to do some spectroscopy...  When I try to measure
the absolute wavelength with a Burliegh Wavemeter (Michealson
interferomter) I get a range of values all over the place between 645

I'm looking for/ to build a 580-625nm yellow-orange laser for display
(to build from parts or even from scratch- except glass-blowing) I've
scoured Sam's FAQ, and I know about home-built Dye lasers, he-ne, and
even found a 150mw 622nm direct-inj. diode (that has to kept at 0

Just acquired a 41x31 inch fresnel lens made by DNP.  The number on the lens
is 491P043A90.  What type of lens is this specifically (linear fresnel,
etc)?
Thanks, in advance, for your help.

I have a doubt related to how an FT IR spectrometer works. If the IR
frequency is modulated through the moving mirror velocity and this
impinges on the sample and then on the detector, how can the sample
absorb energy in the IR frequency spectrum range?

Is it possible to generate gluon-jets within the earth's atmosphere
using lasers? If so, what intensities and wavelengths would be
required? My guess is that the wavelength would need to be in the
gamma-ray region. The intensity would need to be strong enough that it

Dear Fellow Bug Eyes,
   I'm going through the process of buying my first personal microscope and
am somewhat perplexed. I'm not unfamiliar with microscopes but in my prior
incinerations as an undergrad and grad student someone else always set up

Since Ed mentioned his Stereozooms, I would like to know if anyone has a
source for an objective lens pair (it seems to be a single piece) for a
Stereozoom 7. The one I got looked dirty; I tried cleaning it, but no
good. I then removed the lens to clean the rear of the glass, but ...

I'm working on an experimental setup and this group has been very
helpful in the development - thanks everyone!  I am currently trying
to find GRIN lenses for focusing 635nm light from a single mode
fiber.  I would like to find a GRIN with 0.3 or 0.31 pitch, which is a

I am designing a device that will project a 35mm wide object onto a 7mm camera sensor (3MP). One of the objectives is to keep the distance between the object and the sensor small (less than 20cm or 8").
I understand that if I just use a single double concave lens, in theory, it ...

Ever? What is it? Spam or something?

I desire to build a solar furnace with a fresnel lens.  After some
searching, I came across this candidate:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G16400
The only question I have is whether or not this highly concentrates light,

So, I was discussing possible sources of polarization in the spectrometer
with the guy who runs the lab, and he thought that mirrors might also
have a polarizing influence.  Now, I know that an interface between two
transparent media can act as a polarizer (i.e., Brewster's angle) ...