User talk:Ems57fcva

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A nice cup of tea and a sit down to you!, DVdm (talk) 10:45, 22 December 2007 (UTC)

[edit] DC Meetup on May 17th

Your help is needed in planning Wikipedia:Meetup/DC 4! Any comments or suggestions you have are greatly appreciated. The Placebo Effect (talk) 19:20, 8 March 2008 (UTC)

[edit] Wikipedia:Meetup/DC 4

Please note that there is a DC Meetup planned for May 17th at 5:00 p.m., though a place has not yet been set. You're receiving this notice because you posted to the page for the prior meetup - Wikipedia:Meetup/DC 3 - but haven't indicated whether or not you're interested in attending this one. (Apologies if in fact you have.) BetacommandBot (talk) 01:07, 5 May 2008 (UTC)

[edit] Frame dragging experiment

Hi EMS, my name is Nico Benschop (The Netherlands), and I just saw your remarks in Wikipedia on the Lense-Thirring effect (frame dragging in GR theory) and the Sagnac effect (fiber optic gyroscope). I've been thinking lately of an experiment to show 'frame-drag' (resp. ether-drag) in the laboratory, as follows.

Take a Sagnac fiber-optic setup and insert a fast rotating (speed R rps) heavy cylinder (mass M). The fiber length is L meters, wound in many turns around the cylinder at short distance from it.

Interferometry of the clockwise and anti-clockwise light from the two respective fibers, using monochrome laser light (e.g. red, from a CD player laser with ca. 1 micron wavelength, so some 10^6 periods per meter fiber), should show an interference pattern with a delay (phase shift) proportional to the product L.R.M. So for instance a light and a heavy cylinder should make a difference, as would low and high speed rotation.

Since the frame-dagging effect is very small ( 1:10^{-9} ?), a heavy cyclinder (lead) should be used, with a long wound double fiber, and a very high speed rotation (I'm thinking of my coffee grinder;-)

If you by any chance are familiar with such experiment, please let me know (then I won't have to do it myself). Or if the effect would be too weak for such laboratory test with reasonable parameters (L, R, M) I would be obliged to hear from you.

Thanking for your time, with my best regards - dr. Nico F. Benschop (formerly with Philips Research Labs, Eindhoven, NL) —Preceding unsigned comment added by 77.248.151.33 (talk) 14:35, 10 June 2008 (UTC)