Re: Camera obscura

[Brian Whatcott <betwys1@SBCGLOBAL.NET>]

This note of Ludwik's was quite provocative.

Visualizing X-rays at 2 keV was not something
I had considered possible.
 I very much liked the idea of using a pin hole
in a metal box with an xray film plate
to visualize (say) a a paper pin high field emitter
 impinging on a metal plate  in an evacuated jam-jar ,
or perhaps an old thermionic tube, activated
 with a few kV.

I will admit to difficulty with the unit#98
item which Ludwik interjected into his note
 - excess heat seems quite unrelated to
 visualizing X ray emission, on its face.

Brian
p.s. I also confirm Bob's observation that
 so called web cam pin holes are mini-lenses.


At 10:56 AM 8/16/2003 -0700, you wrote:
> Many think that the device known as "camera
> obscura" has only historical significance. In a
> message from a friend I see that he uses this
> device to map the distribution of soft X-rays
> (about 1.5 keV) over the surface at which they
> are emitted. Here is the quote:
>
> ". . . camera-obscura (objective diameter 0.3mm)
> with fixing the X-ray emission onto the X-ray film and
> nuclear emulsion . . . "  I will write more about these
> strange X-rays in a unit at my web site devoted to
> cold fusion. By the ways, unit #98 on that site:
>
> http://blake.montclair.edu/~kowalskil/cf/
>
> is about cold fusion experiments performed by
> students at Portland State University. Can
> somebody give other examples of using a
> pinhole camera in research today?
> Ludwik Kowalski


Brian Whatcott    Altus OK    Eureka!