Sagnac Idiocy
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From: George Dishman on 29 Sep 2007 04:42 "Dr. Henri Wilson" <HW@....> wrote in message news:vn2rf31bqlhe87rq39df4ora78qk044qo5(a)4ax.com... > On Fri, 28 Sep 2007 00:09:49 -0700, George Dishman > <george(a)briar.demon.co.uk> wrote: >>On 27 Sep, 23:07, HW@....(Henri Wilson) wrote: >>> On Tue, 25 Sep 2007 01:45:35 -0700, George Dishman >>> <geo...(a)briar.demon.co.uk> wrote: >>> >On 16 Sep, 23:18, "Androcles" <Engin...(a)hogwarts.physics> wrote: >>> >>> >The light source, mirrors and screen are _all_ >>> >rigidly mounted on the turntable, grandad _is_ >>> >on the roundabout. >>> >>> Interestingly, in the standard ring gyro diagram, eg., >>> http://www.mathpages.com/rr/s2-07/2-07.htm >>> the rotation speed of the 'carousel' is irrelevant. >> >>The whole operation is different. In Sagnac's >>experiment the fringe shift depends on the speed >>of rotation, in a ring gyro it depends on the >>angle through which the table has turned. >> >>> How does SR explain that George?...aren't the fibres solid? >> >>The ring gyro analysis is more complex but the >>easy way to understand it is that the two >>counter-rotating signals create a standing wave. >>When the apparatus rotates, the nulls in the >>standing wave stays where they are because the >>speed of both beams is c in the inertial frame >>and the detector moves past them. If you imagine >>a setup with 360 cycles of the wave round the >>ring, each cycle counted represents 1 degree of >>rotation. >> >>> >According to ballistic theory, in the co-rotating >>> >(roundabout) frame, the kids both run the length >>> >of the circumference at the same speed so take the >>> >same time. In the playground frame, they run at c+v >>> >and c-v but the kid running with the roundabout >>> >has to go farther to catch up to grandad while the >>> >other kid has grandad moving towards him and again >>> >the times are equal. That means no fringe shift. >>> >>> It would according to the above ...but that's not what happens.... >> >>Right, ballistic theory gives the wrong answer, >>but if you calculate the time difference based >>on the kids speed relative to the grass being >>the same regardless of the speed of the >>roundabout then you get the right answer, and >>it doesn't matter how many mirrors are used or >>whether they are all at the same radius or not, >>nor what angles the beams hit the mirrors. That >>is the SR explanation of course, the speed of >>the light is independent of the speed of the >>source (grandad). > > :) > > have a look at my latest Sagnac revelation George. A link would help. > ...then hide your head with > embarrassment.... You've had ten years to learn what I said above and I am still having to explain it to you yet again so I'm not the one who should be embarrassed. George
From: Dr. Henri Wilson on 29 Sep 2007 17:22 On Sat, 29 Sep 2007 09:42:34 +0100, "George Dishman" <george(a)briar.demon.co.uk> wrote: > >"Dr. Henri Wilson" <HW@....> wrote in message >news:vn2rf31bqlhe87rq39df4ora78qk044qo5(a)4ax.com... >> On Fri, 28 Sep 2007 00:09:49 -0700, George Dishman >> <george(a)briar.demon.co.uk> wrote: >>>On 27 Sep, 23:07, HW@....(Henri Wilson) wrote: >>>> On Tue, 25 Sep 2007 01:45:35 -0700, George Dishman >>>> <geo...(a)briar.demon.co.uk> wrote: >>>> >On 16 Sep, 23:18, "Androcles" <Engin...(a)hogwarts.physics> wrote: >>>> >>>> >The light source, mirrors and screen are _all_ >>>> >rigidly mounted on the turntable, grandad _is_ >> >> :) >> >> have a look at my latest Sagnac revelation George. > >A link would help. the link is provided in the thread. www.users.bigpond.com/hewn/sagnac.jpg >> ...then hide your head with >> embarrassment.... > >You've had ten years to learn what I said above >and I am still having to explain it to you yet >again so I'm not the one who should be embarrassed. You will be. there's not much of your theory left now. >George > Henri Wilson. ASTC,BSc,DSc(T) www.users.bigpond.com/hewn/index.htm
From: George Dishman on 29 Sep 2007 18:20 "Dr. Henri Wilson" <HW@....> wrote in message news:ecgtf3pgiqdijrnabpl20foo8avt5oiqn4(a)4ax.com... > On Sat, 29 Sep 2007 09:42:34 +0100, "George Dishman" > <george(a)briar.demon.co.uk> wrote: >>"Dr. Henri Wilson" <HW@....> wrote in message >>news:vn2rf31bqlhe87rq39df4ora78qk044qo5(a)4ax.com... >>> have a look at my latest Sagnac revelation George. >> >>A link would help. > > the link is provided in the thread. Which thread in which group? George
From: Dr. Henri Wilson on 29 Sep 2007 19:18 On Sat, 29 Sep 2007 23:20:22 +0100, "George Dishman" <george(a)briar.demon.co.uk> wrote: > >"Dr. Henri Wilson" <HW@....> wrote in message >news:ecgtf3pgiqdijrnabpl20foo8avt5oiqn4(a)4ax.com... >> On Sat, 29 Sep 2007 09:42:34 +0100, "George Dishman" >> <george(a)briar.demon.co.uk> wrote: >>>"Dr. Henri Wilson" <HW@....> wrote in message >>>news:vn2rf31bqlhe87rq39df4ora78qk044qo5(a)4ax.com... >>>> have a look at my latest Sagnac revelation George. >>> >>>A link would help. >> >> the link is provided in the thread. > >Which thread in which group? http://www.users.bigpond.com/hewn/sagnac.jpg sci.physics.relativity >George > Henri Wilson. ASTC,BSc,DSc(T) www.users.bigpond.com/hewn/index.htm
From: Jerry on 30 Sep 2007 12:58
On Sep 30, 9:14 am, "George Dishman" <geo...(a)briar.demon.co.uk> wrote: > "Jerry" <Cephalobus_alie...(a)comcast.net> wrote in message > > Henri believes that a Sagnac apparatus needs to be > > accelerated from zero rotational velocity in order to > > yield an integrated current rotational velocity. He > > believes that if a Sagnac apparatus is turned on while > > it is in a constant state of rotation, it will measure > > no fringe shift. > > Oh good grief, he's not back to that again. I > straightened him out on that during the thread > in late 2005 referenced above. If you look at > the rest of the post beside the bit on constant > velocity, it was discussing the effect of angular > acceleration. It's quite amazing, actually. Henri has been forced to admit that the conventional analysis is correct in stating that BaTh predicts no fringe displacement during constant rotation... so obviously, thinks he, Sagnac works by measuring cumulative fringe displacements during angular acceleration. "Fringes don't move during a period of CONSTANT angular velocity. Both path lengths change during - and only during - an acceleration and that's when the number of wavelengths in each beam changes. In other words, fringe movement occurs. A simple gyro counts the number moved and converts that into angle." http://groups.google.com/group/sci.physics.relativity/msg/8f2bb996a5941d6d > > Arguing along these lines, Henri falsely asserts that > > the Michelson-Gale experiment must have yielded a null > > result since Michelson had no means of stopping and > > starting the Earth's rotation: > >http://groups.google.com/group/sci.physics.relativity/msg/5c79776b55d... > > Clueless. Henry, the Sagnac experiment gives a > fringe displacement (remember the discussion of > terminology with Jim Greenfield?) which is > proportional to the angular velocity when that > velocity is constant. Jerry |