Date: Thu, 9 Sep 2010 07:15:30 -

Author: Cliff Bettis

Subject: Re: Lorentz Contraction demonstration



We're going to use a blue laser and the Fabry-Perot cavity is 50,000
wavelengths long so we ought to be able to see a fractional change off the
peak, presuming noise (like side to side jitter on the air track) doesn't
wash out the results.


-----Original Message-----
From: [] On
Behalf Of Steve Wonnell
Sent: Thursday, September 09, 2010 6:00 AM
To: tap-l
Cc: Steve Wonnell
Subject: Re: [tap-l] Lorentz Contraction demonstration


I haven't.

I calculate a length contraction by a factor
of about (1 - 5.55e-18) for a velocity of 1 m/s.

For a spacing of 1 meter, ther'd be (1/632e-9) or about 1.58e6
wavelengths of red light, and the contraction would amount
to about 8.8e-12 wavelengths, or about a pico-wavelength,
if I've done my calculations correctly.

Awfully small.

Would it be just to illustrate the concept?

Steve W.

On Wed, 8 Sep 2010, Cliff Bettis wrote:

> Date: Wed, 08 Sep 2010 13:43:07 -0500
> From: Cliff Bettis
> Reply-To:
> To: tap-l
> Subject: [tap-l] Lorentz Contraction demonstration
> Have any of tried this: putting a Fabry-Perot interferometer on an air
> track, aiming a laser at it from the lab frame and then moving the
> interferometer on the track?
> Cliff