[GRLUG] OFF TOPIC - Speaking of Infrared...

[Bob Kline]

On Thu, Jan 28, 2010 at 6:03 PM, Michael Mol <mikemol at gmail.com> wrote:

>
> The chief problem with "darkvision" as it applies to passive near-IR is
> that there is a lot of ambient near-IR radiation that's not related to
> warm bodies.
>
> In short, your warm body radiation in the near-IR will be there, but
> largely drowned out by the ambient near-IR radiation.**
>

The peak wavelength for a human body
thermal spectrum is 10 microns - in the so
called long-wave infrared range.  You shine
if you're standing out in the snow,  but the
human body is not really very hot.  About
the same as your house interior, which is
that temperature, by design. So you don't
stand out much.

See http://en.wikipedia.org/wiki/Infrared

    -- Bob


>
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