Sagnac Idiocy
in [Relativity]
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From: Jeckyl on 16 Sep 2007 19:00 "Androcles" <Engineer(a)hogwarts.physics> wrote in message news:3KfHi.108586$xp6.107080(a)fe3.news.blueyonder.co.uk... > > "JanPB" <filmart(a)gmail.com> wrote in message > news:1189965219.845014.89940(a)o80g2000hse.googlegroups.com... > : On Sep 16, 6:27 am, "Jeckyl" <no...(a)nowhere.com> wrote: > : > "Androcles" <Engin...(a)hogwarts.physics> wrote in message > : > > : > news:gL5Hi.105433$xp6.2039(a)fe3.news.blueyonder.co.uk... > : > > : > > http://www.androcles01.pwp.blueyonder.co.uk/Sagnac/SagnacIdiocy.htm > : > > : > Yeup .. your Q and A at the end is idiocy alright. > : > > : > You obviously don't understand SR or Sagnac. > : > : I think > Don't be silly, when have you ever thought? [snip idiocy from Androcles .. who couldn't discuss physics if his life depended on it and thake the cowardly approach of resortign to insults instead]
From: JM Albuquerque on 16 Sep 2007 19:52 "Dirk Van de moortel" <dirkvandemoortel(a)ThankS-NO-SperM.hotmail.com> escreveu na mensagem news:W3eHi.108551$6t7.5398598(a)phobos.telenet-ops.be... > > I have you seen his MMX-mirror orientation on > http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/AndroMMX.html The only reason why the mirror is oriented at 180 degrees from that is because that's the only way to put the detector outside the experiment. Like here, for the very same reason: http://en.wikipedia.org/wiki/Image:Sagnac_interferometer.png A 180 degrees rotation doesn't add nothing new, or different. For any layman the Androcles's picture is far better because avoids any confusion for the reader. It looks like that you are very short in arguments, like Dono, and so on.
From: JM Albuquerque on 16 Sep 2007 20:25 "Jeckyl" wrote: Nothing.
From: Jeckyl on 16 Sep 2007 21:14 "JM Albuquerque" <jmDOTa2(a)clix.pt> wrote in message news:5l6013F6idrsU1(a)mid.individual.net... > > "Jeckyl" wrote: > > Nothing. JM Albuquerque understood Nothing If you had read what I'd written I explained some of your concerns
From: JM Albuquerque on 16 Sep 2007 21:34
"Jeckyl" <noone(a)nowhere.com> escreveu na mensagem news:13eqchm6i2ehk27(a)corp.supernews.com... > "Androcles" <Engineer(a)hogwarts.physics> wrote in message > news:gL5Hi.105433$xp6.2039(a)fe3.news.blueyonder.co.uk... >> http://www.androcles01.pwp.blueyonder.co.uk/Sagnac/SagnacIdiocy.htm > > Yeup .. your Q and A at the end is idiocy alright. > > You obviously don't understand SR or Sagnac. > > And note that the animation you show is incomplete (you stop it before the > beams return to the source .. I wonder why), and shows the ballistic > theory prediction that the pulses will meet the source at the same place > at the same time and so with no phase difference, which does not give the > observed results (Sagnac refutes ballistic theories and support SR ad > ether theories). From my point of view you are the one that don't understand what Sagnac's "invention" is. This is plain simple. Sagnac is a direct measument of the speed of light taken by an observer moving at "2v". Let's look at the setup: http://en.wikipedia.org/wiki/Image:Sagnac_interferometer.png The beam of light (the source) is stationary. The detector is stationary. The 4-mirrors rotate rigidly. Let's assume by hypothesis that we can spin those mirrors very fast. About half the speed of light or so. And let's assume that we want to measure the one-way speed of light (clockwise for instance). Forget the counter-clockwise ray of light. Since we have a very high spin, it will be possibly to measure the one-way speed of light by doing the following comparison: We need to compare the speed of light measured by a set of 4-mirrors stationary, with that measured by a Sagnag 4-mirrors spinning at half the speed of light. We need to have two similar apparatus, one stationary and other spinning very fast. Then compare the frequency measurements and say that the relative speed of light measured by observers will the subtraction of the read frequencies? The problem is that we cannot have such high speeds and we still need to guarantee full coherence of two separate beams of light. The great invention about Sagnac's setup are two things that its achieves (specially the second): 1 - To double the possible angular speed; 2 - To achieve means that the same beam of light could be used as a source and also to provide means of detection, so that the all apparatus guarantee that full coherence exists and so we simply can measure the most tiny variation on the speed of light by means of the most tiny shift in frequency. Basically, on the Sagnac's apparatus the same beam of light is used for readings on a stationary FoR and simultaneously read on the rotating FoR, all at once. In fact, we don't have such stationary FoR, but everybody works the problem based on it, then deduce the vary same reasoning for the other way around, and say that in the final they cancel each other out to give the stationary FoR taken in first place. The really ingenious about Sagnac is that it achieves means to have the same beam of light to interfere with itself. Most certainly this sounds bad, but if you really think about it and forget religions... and see the obvious. |