Declan --

I'll stick my neck out a bit here.

Several years and at least a couple of lives ago, I took a detour into the
wonderful world of optics.  Here are a few things I remember --

All physical bodies above the temperature of absolute zero emit
electromagnetic radiation in a characteristic spectrum dependent on their
absolute temperature.  The amplitude and wavelength of this  spectrum can be
approximated by the so called "black body radiation" curve.  A so called
"black body" is an idealized radiating object of a known temperature which
meets certain criteria such as not reflecting or passing any radiation,
i.e., it is completely absorbing of all incident radiation.  It is often
thought of as a box (or a sphere) with a hole in it, which is completely
coated on the interior with soot (carbon), i.e., "black".

Depending on temperature, bodies radiate in the far infrared (for very cool
bodies [my wife for example]) to the gamma region (for _very_ hot bodies.

Try the following two links for further useful reading, including some
examples of the radiation curves of the human body and the sun given in the
second link.

http://www.phys.virginia.edu/classes/252/black_body_radiation.html

http://www.unidata.ucar.edu/staff/blynds/tmp.html#Uni

Caveat -- I make no representation of being an authority in the field of
optical physics, the above is only what stuck to me on my tour through the
wonderful world of optics and radiation physics.

Hopefully, Uwe will catch any gross errors that I have made.

    Happy detecting, Bob Smith


---   Avoid computer viruses, Practice safe hex  ---

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Robert L. (Bob) Smith
Smith Machine Works, Inc.
9900 Lumlay Road
Richmond, VA 23236   804/745-1065

  [EMAIL PROTECTED]

----- Original Message ----- 
To: "Multiple recipients of list CHIPDIR-L" <[EMAIL PROTECTED]>
Sent: Wednesday, November 19, 2003 7:28 AM


> On Wed, Nov 19, 2003 at 03:49:55AM -0800, Tinco Brouwer enlightened us
> thusly
> > >
> > >What I am looking for is reading to check the feasability. I need the
> > >freauencies that everything emits. We all enjoy discussing the design
> > >strategy, but I haven't given out enough info to get much help on
> > >that.  Where I need the help is a treatment of what frequencies
> > >things emit (Particularly people and the sun).
> > >
> > >
> > >
> > Are talking about optical wavelengths? There are a lot of sites where
> > you can find solar spectra under different conditions.  I can't give
> > away too much info, but there exists extremely small optical bandpass
> > glass filters (I have used a Schott filter..).
>
> Thanks. This is annoying me big time as everyone is talking spectra but
> not so many give numbers. I'll look again. Maybe iut was just a poor
> choice of earch eywords.
> -- 
>
> With best Regards,
>
>
> Declan Moriarty.
> -- 
> Author: Declan Moriarty
>   INET: [EMAIL PROTECTED]
>
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-- 
Author: Robert Smith
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