I heard rumor the military was working on a cloaking system that had tiny
light receivers on one side of a military vehicle and light emitters on the
other.
The vehicle could see everything to one side of it and broadcast the same
image on its side.

Cool huh?

----- Original Message -----
From: "jbange" <hfinn@INGRATES.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, October 21, 2004 9:04 PM
Subject: Re: noise reduction

> At 06:25 PM 10/21/2004, you wrote:
> >Why don't you use a noise cancelling system?  Measure the frequency of
the
> >noise, and run it through your stereo amplifier phase shifted 180
> >degrees?  You might even be able to make it automatically adjustable
based
> >on MPH.
>
> That'd only work if the original noise was coming from behind the
speakers.
> The "anti-noise" has to be projected in the same direction the noise is
> coming from in order to match the waveforms so they cancel. I'm waiting
for
> them to develop a double-layered piezo sandwich material, with the bottom
> layer acting as the microphone and the top layer transmitting the
> anti-noise. It'd in theory be a perfect soundproofing material. Something
> like that's a long way off, though...
>
> John Bange
> '90 Vanagon "Geldsauger"