----- Original Message ----- 
From: 
To: 
Sent: Saturday, April 24, 2010 2:28 PM
Subject: Re: Laser Pointer / Mirrors etc...


> In a message dated 24/04/2010, gmvoeth@........... writes:
> 
> I have  this laser pointer and was just wondering how it might be used with 
> mirrors to  detect ground motions ?
> Hi Geoff,
> 
>    It is NO USE. These small lasers are VERY noisy and  the intensity 
> drifts a lot with temperature.

Ok, Ill just use it to help balance the cieling fans.

> 
> How  about two silvered surfaced mirrors that bounce the light
> between them at a  slight angle sort of like you see yourself
> a zillion times in a mirror at  the barber shop ??
> a teeter totter mirror bouncing off a light beam  ?
> 
> What kind of sensor for a red LED laser pointer ?
>    Any ideas ?
> 
>    A couple of large area silicon photocells and  a small filament bulb 
> work very well. In some measurements I found that I could  resolve motions 
> down to less than 15 nano metres.

None of this makes sense to me.
Wonderful things has been done with light like
taking microsecond photographs with mirrors.

I would think a no-mass lightbeam might be the very best
way to go if someone can figure it out.

Somewhere is something so simple and straight forward
it must be a military secret.
:-(

> 
>    Regards,
> 
>    Chris Chapman
> 
> 
>
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