The Sagnac Effect revisited
in [Relativity]
|
Prev: NICAP - UFOS -Tourism
Next: What is your EM crankosity?
From: Jonah Thomas on 21 Sep 2009 01:33 "Inertial" <relatively(a)rest.com> wrote: > "Jonah Thomas" <jethomas5(a)gmail.com> wrote > > "Inertial" <relatively(a)rest.com> wrote: > >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote > >> > doug <xx(a)xx.com> wrote: > >> >> Jonah Thomas wrote: > >> > Why not respond on substantive grounds and explain why my > >argument> > is wrong? > >> > >> I've explained it to you over and over. Emissions theories get it > >> wrong because when you analyze them they give a zero phase shift at > >> the detector in sagnac. > >> > >> The only way not to get that is to have strange reflection > >properties> for light that alter its speed in exactly the right way > >to get the> correct results. > > > > Let's make sure I understand what you're saying. Emission theories > > have the light that's emitted in different directions from a moving > > source get different speeds. > > No .. the speed is c. Always c. ?? Are you saying that emission theories do not predict that the speed of light varies with the speed of the light's source? What I say is wrong about this is that in the original experiment (and often even today) you do not start with light emitted in two different directions. You have a single beam of light that is made to travel in two different directions. And most emission theories (with the notable exception of the Ritz version) say that when you have light emitted in one direction from a moving source, that light has one speed. So the above explanation does not fit this case. Emission theories do not predict two different speeds for the light in the Sagnac experiment. They predict one speed, just like all the other theories. Since there is only one speed for the light, the light that takes the longer path will arrive later, and Bob's your uncle. > > So the above explanation does not fit this case. Emission theories > > do not predict two different speeds for the light in the Sagnac > > experiment. They predict one speed, > > In the inertial frame, two speeds, different lengths of path .. so > arrive same time .. so no phase shift No, one speed, different path lengths, arrive at the same time that other theories predict. Because emission theories predict that light which is emitted by sources moving at different speeds will have different speeds. But the original Sagnac experiment used light emitted by a single source, not by sources moving at different speeds. > > just like all the other theories. Since there is > > only one speed for the light, the light that takes the longer path > > will arrive later, and Bob's your uncle. > > Wrong OK, tell me why it's wrong.
From: Jonah Thomas on 21 Sep 2009 01:36 "Inertial" <relatively(a)rest.com> wrote: > "Jonah Thomas" <jethomas5(a)gmail.com> wrote > > Jerry <Cephalobus_alienus(a)comcast.net> wrote: > >> Jonah Thomas <jethom...(a)gmail.com> wrote: > >> > Jerry <Cephalobus_alie...(a)comcast.net> wrote: > >> > > It is Miller (1924) which refutes the Ritzian version of > >emission> > > theory, not Sagnac, so your understanding of what > >Sagnac does or> > > does not demonstrate is absolutely, completely, > >totally off-base.> > > >> > You're right. That leaves us with the traditional Sagnac > >experiment> > not contradicting any emission theory. > >> > >> You are, as I've said, absolutely, completely, totally off-base. > > > > Then why not respond to my actual argument? > > He has, quite extensively, about each of the various emission > theories. > > I'm not sure what your argument are anymore. Certainly your claim > that all emissions theories predict the observed Sagnac result is > completely wrong. Emission theories predict different speeds of light etc for sources that move at different speeds. The Sagnac experiment for many years was done only with light from a single source, that did not move at different speeds. So the emission theories would predict not different speeds but a single speed just like every other theory. If you think emission theories would predict different lightspeeds in that circumstance, tell me why you think so.
From: Inertial on 21 Sep 2009 01:43 "Jonah Thomas" <jethomas5(a)gmail.com> wrote in message news:20090921013329.295fe058.jethomas5(a)gmail.com... > "Inertial" <relatively(a)rest.com> wrote: >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote >> > "Inertial" <relatively(a)rest.com> wrote: >> >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote >> >> > doug <xx(a)xx.com> wrote: >> >> >> Jonah Thomas wrote: > >> >> > Why not respond on substantive grounds and explain why my >> >argument> > is wrong? >> >> >> >> I've explained it to you over and over. Emissions theories get it >> >> wrong because when you analyze them they give a zero phase shift at >> >> the detector in sagnac. >> >> >> >> The only way not to get that is to have strange reflection >> >properties> for light that alter its speed in exactly the right way >> >to get the> correct results. >> > >> > Let's make sure I understand what you're saying. Emission theories >> > have the light that's emitted in different directions from a moving >> > source get different speeds. >> >> No .. the speed is c. Always c. Sorry .. I misread Its always c relative to the source. > ?? Are you saying that emission theories do not predict that the speed > of light varies with the speed of the light's source? c+v where the source has speed c > What I say is wrong about this is that in the original experiment (and > often even today) you do not start with light emitted in two different > directions. You have a single beam of light that is made to travel in > two different directions. Yes .. it is split into two different directions and both travel at c relative to the splitter .. which means in the non-rotating frame it goes as c+v and c-v .. just as per emission theory analysis > And most emission theories (with the notable exception of the Ritz > version) say that when you have light emitted in one direction from a > moving source, that light has one speed. One velocity per inertial frame, yes. One thing only has one speed in a given frame. And if you split it into two directions, then you get two speeds which will generally be different in different frames > So the above explanation does not fit this case. Emission theories do > not predict two different speeds for the light in the Sagnac experiment. Wrong .. they do > They predict one speed, Wrong > just like all the other theories. Since there is > only one speed for the light, the light that takes the longer path will > arrive later, and Bob's your uncle. Wrong. Totally wrong >> > So the above explanation does not fit this case. Emission theories >> > do not predict two different speeds for the light in the Sagnac >> > experiment. They predict one speed, >> >> In the inertial frame, two speeds, different lengths of path .. so >> arrive same time .. so no phase shift > > No, one speed, different path lengths, arrive at the same time that > other theories predict. Not in emission theory > Because emission theories predict that light which is emitted by sources > moving at different speeds will have different speeds. But the original > Sagnac experiment used light emitted by a single source, not by sources > moving at different speeds. It is emitted in different directions and so has different speeds This is basic basic physics >> > just like all the other theories. Since there is >> > only one speed for the light, the light that takes the longer path >> > will arrive later, and Bob's your uncle. >> >> Wrong > > OK, tell me why it's wrong. I just did
From: Inertial on 21 Sep 2009 01:44 "Jonah Thomas" <jethomas5(a)gmail.com> wrote in message news:20090921013620.3450f416.jethomas5(a)gmail.com... > "Inertial" <relatively(a)rest.com> wrote: >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote >> > Jerry <Cephalobus_alienus(a)comcast.net> wrote: >> >> Jonah Thomas <jethom...(a)gmail.com> wrote: >> >> > Jerry <Cephalobus_alie...(a)comcast.net> wrote: > >> >> > > It is Miller (1924) which refutes the Ritzian version of >> >emission> > > theory, not Sagnac, so your understanding of what >> >Sagnac does or> > > does not demonstrate is absolutely, completely, >> >totally off-base.> > >> >> > You're right. That leaves us with the traditional Sagnac >> >experiment> > not contradicting any emission theory. >> >> >> >> You are, as I've said, absolutely, completely, totally off-base. >> > >> > Then why not respond to my actual argument? >> >> He has, quite extensively, about each of the various emission >> theories. >> >> I'm not sure what your argument are anymore. Certainly your claim >> that all emissions theories predict the observed Sagnac result is >> completely wrong. > > Emission theories predict different speeds of light etc for sources that > move at different speeds. And for light in different directions. Eg for light in same direction as the source is moving, speed is c+v, fro light in opposite direction, speed is c-v > The Sagnac experiment for many years was done only with light from a > single source, that did not move at different speeds. But different directions, so different speed This is SOOO damned basic. > So the emission theories would predict not different speeds but a single > speed just like every other theory. Wrong > If you think emission theories would predict different lightspeeds in > that circumstance, tell me why you think so. I just did. Plaase .. THINK about what you're saying.
From: Jerry on 21 Sep 2009 01:50
On Sep 21, 12:20 am, Jonah Thomas <jethom...(a)gmail.com> wrote: > "Inertial" <relativ...(a)rest.com> wrote: > > "Jonah Thomas" <jethom...(a)gmail.com> wrote > > > doug <x...(a)xx.com> wrote: > > >> Jonah Thomas wrote: > > > >> > I was disappointed that so many people claim the Sagnac > > >experiment> > refuted most emission theories when it did not at all. > > >Perhaps the> > competent scientists were thinking about something > > >else while these> > other people made these distressing false claims. > > > >> Or you do not understand any of the physics done in the last > > >> century. However, you are free to believe what you want and > > >> are not bound to believe in reality. > > > > Why not respond on substantive grounds and explain why my argument > > > is wrong? > > > I've explained it to you over and over. Emissions theories get it > > wrong because when you analyze them they give a zero phase shift at > > the detector in sagnac. > > > The only way not to get that is to have strange reflection properties > > for light that alter its speed in exactly the right way to get the > > correct results. > > Let's make sure I understand what you're saying. Emission theories have > the light that's emitted in different directions from a moving source > get different speeds. So in the Sagnac experiment, the light that's > emitted in different directions gets different speeds, precisely enough > that the light arrives at the detector at the same time. All other > theories say that the light which has the longer path arrives later, and > so there are interference effects. But emission theories have it arrive > at the same time and in phase and so there is no interference. > > Do I understand? > > What I say is wrong about this is that in the original experiment (and > often even today) you do not start with light emitted in two different > directions. You have a single beam of light that is made to travel in > two different directions. > > And most emission theories (with the notable exception of the Ritz > version) say that when you have light emitted in one direction from a > moving source, that light has one speed. > > So the above explanation does not fit this case. Emission theories do > not predict two different speeds for the light in the Sagnac experiment. > They predict one speed, just like all the other theories. Since there is > only one speed for the light, the light that takes the longer path will > arrive later, and Bob's your uncle. > > There may be recent examples which do not do it that way. You could have > carefully tuned lasers that are actually aimed in the appropriate > directions, that interfere. But for a very long time that was not > available, and the claims that the original Sagnac experiment disproved > emission theories were based on a ridiculously mistaken idea what > emission theories predict. > > Am I wrong? Yes. Let us examine the Tolman version of emission theory. Tolman accepts the QED explanation of metallic reflection as due to the coherent re-radiation of light by conduction electrons. Light is emitted at c with respect to the mirror or beam splitter. Likewise, light passing -through- a beam splitter emerges at c with respect to the beam splitter, since the passage of light through a transparent material represents coherent absorption and re-radiation of light without loss, but with phase lag resulting in a lowered speed of light through the transparent material. The beam splitter, moving at v, therefore acts as a source of c+v and c-v light. As the light is reflected off each mirror in turn, its speed in our frame equals c plus the velocity component of the reflecting mirror that is in the direction of the emergent beam. The net result is zero fringe shift. A proper analysis of the Thomson & Stewart version of emission theory yields a non-zero fringe shift of the wrong magnitude, when performed on a mirrored Sagnac apparatus. Both Tolman and Thomson & Stewart give zero fringe shift in a mirror-less Sagnac apparatus. Whether Ritz gives a zero fringe shift in a mirror-less Sagnac apparatus depends on whether the c+v/c-v rules governing the reflection of light represents a phenomenological property of mirrors or, alternatively, a fundamental property of light. The notion that light should retain a memory of its original state of motion is so crazy, that the interpretation of the Ritz reflection rules as a mere phenomenological property of mirrors would seem to be preferred. Jerry |