 |
|
| Science Forum Index » Physics - Relativity Forum » Wang / Sagnac Devices... |
|
Page 1 of 30 Goto page 1, 2, 3 ... 28, 29, 30 Next |
|
| Author |
Message |
| ... |
 Posted: Fri Oct 16, 2009 9:08 am |
|
|
|
Guest
|
I missed the opportunity to comment on this subject when a thread was
started by Jonah Thomas last month. I hope to continue the discussion
from this new starting point.
Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration. There are "Sagnac devices" that can detect
that phenomenon, but they should not be confused with the phenomenon
itself. Examples of the devices are: the passive Sagnac
interferometer devices of Sagnac, Pogany, Michelson-Gale, and
Dufour-Prunier; the active Sagnac interferometer devices of
Macek-Davis, Stedmann, modern laser gyros; and finally the "one-way"
Sagnac system of devices known as GPS.
A simple analogy of the phenomenon can be understood by this example:
Assume you have a long freight car, 100 feet long. There is a dueler
located at each end with identical guns, ammo and skill. If the car
is stationary with respect to the rails or moving at a constant
velocity and both fire their guns at the same time, they both die at
the same time. But, if the train happens to accelerate forward while
the bullets are in flight, the guy at the rear of the car dies first.
The same thing would occur if the car was experiencing acceleration
throughout the gun fight. That, in my opinion, is the phenomenon of
Sagnac. Bullets are flying in two directions covering an equal
distance of 100 feet, but one arrives sooner than the other due to the
acceleration of the receiver.
Paul Anderson was describing a type of device while he thought he was
describing the effect. The generalized Sagnac effect does not deal
with enclosed areas and angular velocity; several detection devices
are based on those criteria, but the phenomenon is not exclusive to
them. Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters. The GPS network is corrected each day to
adjust their clocks so that the one-way transmission of signals is
accurate due to the Sagnac effect. Paul also suggested the Wang
experiment was a modified Fizeau experiment. They used both hollow
fibers and solid cross-section fiber and got the same readings. Others
in the past, Pogany and Harress, investigated the use of glass prisms
in the Sagnac set-up to determine if it was a Fizeau effect, and they
concluded it was not. Post has written about this.
Tom Roberts erroneously states that the ballistic model cannot explain
Sagnac. I will acknowledge that the "re-emission" ballistic model is
denied by the Sagnac results. Tolman (1912) and Panofsky and Phillips
(1961) describe three ballistic models. Waldron (1977) describes two
of the three: the ballistic model of Ritz/Waldron and the re-emission
model. The re-emission model fails in explaining Sagnac and a host of
other experiments.
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v… all with respect to the mirror.
Regards,
Tom Miles |
|
|
| Back to top |
|
|
|
| Dono.... |
| Posted: Fri Oct 16, 2009 9:08 am |
|
|
|
Guest
|
On Oct 16, 8:43 am, tominlag... at (no spam) yahoo.com wrote:
[quote:8dd493665f]On Fri, 16 Oct 2009 08:31:15 -0700 (PDT), "Dono." <sa... at (no spam) comcast.net
wrote:
On Oct 16, 8:08 am, tominlag... at (no spam) yahoo.com wrote:
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v… all with respect to the mirror.
Regards,
Tom Miles
If the speed is ANYTHING but c, the model fails BOTH the Sagnac and
the Ives experiments.
I suspect you are referring to the passive type of interferometer
devices. In that case, you are wrong: whatever the speed of the
initial ray of light, components going in each direction after
splitting will have the same speed, be it c or u. The outcome is the
same. As a practical matter, since the sources in the experiments you
cite are not in motion with respect to the device, the speed will be
c.
[/quote:8dd493665f]
Prove it . Show the math. |
|
|
| Back to top |
|
|
|
| Dono.... |
| Posted: Fri Oct 16, 2009 9:08 am |
|
|
|
Guest
|
On Oct 16, 8:08 am, tominlag... at (no spam) yahoo.com wrote:
[quote:c0414862c0]
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v… all with respect to the mirror.
Regards,
Tom Miles
[/quote:c0414862c0]
If the speed is ANYTHING but c, the model fails BOTH the Sagnac and
the Ives experiments. |
|
|
| Back to top |
|
|
|
| Androcles... |
| Posted: Fri Oct 16, 2009 9:39 am |
|
|
|
Guest
|
<tominlaguna at (no spam) yahoo.com> wrote in message
news:to2hd5pm6nvm8qdul7kecjf5do7imn1ng5 at (no spam) 4ax.com...
[quote:7f7f9e4173]I missed the opportunity to comment on this subject when a thread was
started by Jonah Thomas last month. I hope to continue the discussion
from this new starting point.
Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration. There are "Sagnac devices" that can detect
that phenomenon, but they should not be confused with the phenomenon
itself. Examples of the devices are: the passive Sagnac
interferometer devices of Sagnac, Pogany, Michelson-Gale, and
Dufour-Prunier; the active Sagnac interferometer devices of
Macek-Davis, Stedmann, modern laser gyros; and finally the "one-way"
Sagnac system of devices known as GPS.
A simple analogy of the phenomenon can be understood by this example:
Assume you have a long freight car, 100 feet long. There is a dueler
located at each end with identical guns, ammo and skill. If the car
is stationary with respect to the rails or moving at a constant
velocity and both fire their guns at the same time, they both die at
the same time. But, if the train happens to accelerate forward while
the bullets are in flight, the guy at the rear of the car dies first.
The same thing would occur if the car was experiencing acceleration
throughout the gun fight. That, in my opinion, is the phenomenon of
Sagnac. Bullets are flying in two directions covering an equal
distance of 100 feet, but one arrives sooner than the other due to the
acceleration of the receiver.
Paul Anderson was describing a type of device while he thought he was
describing the effect. The generalized Sagnac effect does not deal
with enclosed areas and angular velocity; several detection devices
are based on those criteria, but the phenomenon is not exclusive to
them. Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters. The GPS network is corrected each day to
adjust their clocks so that the one-way transmission of signals is
accurate due to the Sagnac effect. Paul also suggested the Wang
experiment was a modified Fizeau experiment. They used both hollow
fibers and solid cross-section fiber and got the same readings. Others
in the past, Pogany and Harress, investigated the use of glass prisms
in the Sagnac set-up to determine if it was a Fizeau effect, and they
concluded it was not. Post has written about this.
Tom Roberts erroneously states that the ballistic model cannot explain
Sagnac. I will acknowledge that the "re-emission" ballistic model is
denied by the Sagnac results. Tolman (1912) and Panofsky and Phillips
(1961) describe three ballistic models. Waldron (1977) describes two
of the three: the ballistic model of Ritz/Waldron and the re-emission
model. The re-emission model fails in explaining Sagnac and a host of
other experiments.
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v. all with respect to the mirror.
Regards,
Tom Miles
[/quote:7f7f9e4173]
Correct. Very good analysis. One tiny flaw...
Newton's corpuscles of light model, today called photons, predates
Walter Ritz by 250 years.
Of course a FOG cannot in any way be related to Einstein's relativity,
since that specifically states light is always propagated in empty space
with a definite velocity c which is independent of the state of motion
of the emitting body and a FOG isn't empty space.
Hence Andersen's and Roberts' arguments are non sequitur.
For amusement only:
If the duellists shoot arrows at each other at v feet per second
and the train accelerates at g fps/second, how far apart should
the duellists be to guarantee one of them survives? |
|
|
| Back to top |
|
|
|
| ... |
| Posted: Fri Oct 16, 2009 9:43 am |
|
|
|
Guest
|
On Fri, 16 Oct 2009 08:31:15 -0700 (PDT), "Dono." <sa_ge at (no spam) comcast.net>
wrote:
[quote:b540e3dbcd]On Oct 16, 8:08 am, tominlag... at (no spam) yahoo.com wrote:
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v… all with respect to the mirror.
Regards,
Tom Miles
If the speed is ANYTHING but c, the model fails BOTH the Sagnac and
the Ives experiments.
[/quote:b540e3dbcd]
I suspect you are referring to the passive type of interferometer
devices. In that case, you are wrong: whatever the speed of the
initial ray of light, components going in each direction after
splitting will have the same speed, be it c or u. The outcome is the
same. As a practical matter, since the sources in the experiments you
cite are not in motion with respect to the device, the speed will be
c. |
|
|
| Back to top |
|
|
|
| Jonah Thomas... |
| Posted: Fri Oct 16, 2009 1:35 pm |
|
|
|
Guest
|
tominlaguna at (no spam) yahoo.com wrote:
[quote:45ce711099]Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
[/quote:45ce711099]
Here is why I think there is something else going on too.
________________
/ \
\____x___________/
Here is the simple form of the Wang experiment, with the
emitter-detector x traveling around the loop. When x is on the linear
section traveling at constant speed they get the same phase shift that
they do when it is going around the rollers.
___________________________________
/ \
\____x______________________________/
When they change the length and change nothing else, they get a change
in phase shift proportional to the length. How has this changed the
acceleration proportional to the phase shift? Presumably the light is
getting accelerated when it goes around the rollers, but why is it more
acceleration because of the extra length? They tried a version where
there was no extra Sagnac-area enclosed, too.
[quote:45ce711099]The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration.
[/quote:45ce711099]
I think that's true, because it requires a closed path and how are you
going to get a closed path without changing the direction of the light?
And how can you do that with no acceleration? But I don't yet see that
the effect is proportional to the acceleration. It's proportional to the
linear speed and to the length of the moving fiber.
[quote:45ce711099]Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters.
[/quote:45ce711099]
Interesting! Did they measure whether the effect was the same in the
morning and evening?
While looking for Saburi I found this which may be of some interest:
http://adsabs.harvard.edu/full/1986IAUS..114..299A |
|
|
| Back to top |
|
|
|
| ... |
| Posted: Sat Oct 17, 2009 12:08 am |
|
|
|
Guest
|
On Fri, 16 Oct 2009 09:01:34 -0700 (PDT), "Dono." <sa_ge at (no spam) comcast.net>
wrote:
[quote:0746f37bf2]On Oct 16, 8:43 am, tominlag... at (no spam) yahoo.com wrote:
On Fri, 16 Oct 2009 08:31:15 -0700 (PDT), "Dono." <sa... at (no spam) comcast.net
wrote:
On Oct 16, 8:08 am, tominlag... at (no spam) yahoo.com wrote:
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v… all with respect to the mirror.
Regards,
Tom Miles
If the speed is ANYTHING but c, the model fails BOTH the Sagnac and
the Ives experiments.
I suspect you are referring to the passive type of interferometer
devices. In that case, you are wrong: whatever the speed of the
initial ray of light, components going in each direction after
splitting will have the same speed, be it c or u. The outcome is the
same. As a practical matter, since the sources in the experiments you
cite are not in motion with respect to the device, the speed will be
c.
Prove it . Show the math.
[/quote:0746f37bf2]
I don't know what there is to prove. First, please let me know which
Ives experiment you are discussing. I was not aware of an Ives
experiment that tested the Sagnac effect.
The point I was trying to make was simply that whatever the speed of
the incoming ray was, that speed was retained by the two components
after the ray is split. In other words if the incoming ray is c, the
two components will be c after splitting, not c+v and c-v as they
travel in opposite directions around the device. Further, for all
practical purposes the speed of light is always c in the earth-bound
laboratory when there is no relative motion between the source and the
receiver. Even if you used an extraterrestrial source of light, the
speed of the light reaching the lab would measure at c due to the
extinction process while passing through the atmoshpere. |
|
|
| Back to top |
|
|
|
| ... |
| Posted: Sat Oct 17, 2009 12:37 am |
|
|
|
Guest
|
On Fri, 16 Oct 2009 16:39:37 +0100, "Androcles"
<Headmaster at (no spam) Hogwarts.physics_p> wrote:
[quote:cc5bbb4d19]
tominlaguna at (no spam) yahoo.com> wrote in message
news:to2hd5pm6nvm8qdul7kecjf5do7imn1ng5 at (no spam) 4ax.com...
I missed the opportunity to comment on this subject when a thread was
started by Jonah Thomas last month. I hope to continue the discussion
from this new starting point.
Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration. There are "Sagnac devices" that can detect
that phenomenon, but they should not be confused with the phenomenon
itself. Examples of the devices are: the passive Sagnac
interferometer devices of Sagnac, Pogany, Michelson-Gale, and
Dufour-Prunier; the active Sagnac interferometer devices of
Macek-Davis, Stedmann, modern laser gyros; and finally the "one-way"
Sagnac system of devices known as GPS.
A simple analogy of the phenomenon can be understood by this example:
Assume you have a long freight car, 100 feet long. There is a dueler
located at each end with identical guns, ammo and skill. If the car
is stationary with respect to the rails or moving at a constant
velocity and both fire their guns at the same time, they both die at
the same time. But, if the train happens to accelerate forward while
the bullets are in flight, the guy at the rear of the car dies first.
The same thing would occur if the car was experiencing acceleration
throughout the gun fight. That, in my opinion, is the phenomenon of
Sagnac. Bullets are flying in two directions covering an equal
distance of 100 feet, but one arrives sooner than the other due to the
acceleration of the receiver.
Paul Anderson was describing a type of device while he thought he was
describing the effect. The generalized Sagnac effect does not deal
with enclosed areas and angular velocity; several detection devices
are based on those criteria, but the phenomenon is not exclusive to
them. Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters. The GPS network is corrected each day to
adjust their clocks so that the one-way transmission of signals is
accurate due to the Sagnac effect. Paul also suggested the Wang
experiment was a modified Fizeau experiment. They used both hollow
fibers and solid cross-section fiber and got the same readings. Others
in the past, Pogany and Harress, investigated the use of glass prisms
in the Sagnac set-up to determine if it was a Fizeau effect, and they
concluded it was not. Post has written about this.
Tom Roberts erroneously states that the ballistic model cannot explain
Sagnac. I will acknowledge that the "re-emission" ballistic model is
denied by the Sagnac results. Tolman (1912) and Panofsky and Phillips
(1961) describe three ballistic models. Waldron (1977) describes two
of the three: the ballistic model of Ritz/Waldron and the re-emission
model. The re-emission model fails in explaining Sagnac and a host of
other experiments.
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v. all with respect to the mirror.
Regards,
Tom Miles
Correct. Very good analysis. One tiny flaw...
Newton's corpuscles of light model, today called photons, predates
Walter Ritz by 250 years.
Of course a FOG cannot in any way be related to Einstein's relativity,
since that specifically states light is always propagated in empty space
with a definite velocity c which is independent of the state of motion
of the emitting body and a FOG isn't empty space.
Hence Andersen's and Roberts' arguments are non sequitur.
For amusement only:
If the duellists shoot arrows at each other at v feet per second
and the train accelerates at g fps/second, how far apart should
the duellists be to guarantee one of them survives?
Yes also, on FOG not being related to Einstein's special relativity[/quote:cc5bbb4d19]
(SRT). There are a number of people in a discussion group that I
belong to that insist that Sagnac and Michelson-Gale refute SRT. I
cannot get on that bandwagon because the Sagnac phenomenon resides
exclusively within accelerated FOR.
Very clever puzzle with the arrow scenario… Let us know when you've
worked it out. |
|
|
| Back to top |
|
|
|
| Androcles... |
| Posted: Sat Oct 17, 2009 2:08 am |
|
|
|
Guest
|
<tominlaguna at (no spam) yahoo.com> wrote in message
news:iqoid5dngs6tslqd8muf4iabprhin6rot8 at (no spam) 4ax.com...
[quote:e6003d0809]On Fri, 16 Oct 2009 16:39:37 +0100, "Androcles"
Headmaster at (no spam) Hogwarts.physics_p> wrote:
tominlaguna at (no spam) yahoo.com> wrote in message
news:to2hd5pm6nvm8qdul7kecjf5do7imn1ng5 at (no spam) 4ax.com...
I missed the opportunity to comment on this subject when a thread was
started by Jonah Thomas last month. I hope to continue the discussion
from this new starting point.
Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration. There are "Sagnac devices" that can detect
that phenomenon, but they should not be confused with the phenomenon
itself. Examples of the devices are: the passive Sagnac
interferometer devices of Sagnac, Pogany, Michelson-Gale, and
Dufour-Prunier; the active Sagnac interferometer devices of
Macek-Davis, Stedmann, modern laser gyros; and finally the "one-way"
Sagnac system of devices known as GPS.
A simple analogy of the phenomenon can be understood by this example:
Assume you have a long freight car, 100 feet long. There is a dueler
located at each end with identical guns, ammo and skill. If the car
is stationary with respect to the rails or moving at a constant
velocity and both fire their guns at the same time, they both die at
the same time. But, if the train happens to accelerate forward while
the bullets are in flight, the guy at the rear of the car dies first.
The same thing would occur if the car was experiencing acceleration
throughout the gun fight. That, in my opinion, is the phenomenon of
Sagnac. Bullets are flying in two directions covering an equal
distance of 100 feet, but one arrives sooner than the other due to the
acceleration of the receiver.
Paul Anderson was describing a type of device while he thought he was
describing the effect. The generalized Sagnac effect does not deal
with enclosed areas and angular velocity; several detection devices
are based on those criteria, but the phenomenon is not exclusive to
them. Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters. The GPS network is corrected each day to
adjust their clocks so that the one-way transmission of signals is
accurate due to the Sagnac effect. Paul also suggested the Wang
experiment was a modified Fizeau experiment. They used both hollow
fibers and solid cross-section fiber and got the same readings. Others
in the past, Pogany and Harress, investigated the use of glass prisms
in the Sagnac set-up to determine if it was a Fizeau effect, and they
concluded it was not. Post has written about this.
Tom Roberts erroneously states that the ballistic model cannot explain
Sagnac. I will acknowledge that the "re-emission" ballistic model is
denied by the Sagnac results. Tolman (1912) and Panofsky and Phillips
(1961) describe three ballistic models. Waldron (1977) describes two
of the three: the ballistic model of Ritz/Waldron and the re-emission
model. The re-emission model fails in explaining Sagnac and a host of
other experiments.
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v. all with respect to the mirror.
Regards,
Tom Miles
Correct. Very good analysis. One tiny flaw...
Newton's corpuscles of light model, today called photons, predates
Walter Ritz by 250 years.
Of course a FOG cannot in any way be related to Einstein's relativity,
since that specifically states light is always propagated in empty space
with a definite velocity c which is independent of the state of motion
of the emitting body and a FOG isn't empty space.
Hence Andersen's and Roberts' arguments are non sequitur.
For amusement only:
If the duellists shoot arrows at each other at v feet per second
and the train accelerates at g fps/second, how far apart should
the duellists be to guarantee one of them survives?
Yes also, on FOG not being related to Einstein's special relativity
(SRT). There are a number of people in a discussion group that I
belong to that insist that Sagnac and Michelson-Gale refute SRT. I
cannot get on that bandwagon because the Sagnac phenomenon resides
exclusively within accelerated FOR.
[/quote:e6003d0809]
Sagnac isn't FOG and SRT says:
quote/
It is at once apparent that this result still holds good if the clock moves
from A to B in any polygonal line, and also when the points A and B
coincide.
If we assume that the result proved for a polygonal line is also valid for a
continuously curved line, we arrive at this result: If one of two
synchronous clocks at A is moved in a closed curve with constant velocity
until it returns to A, the journey lasting t seconds, then by the clock
which has remained at rest the travelled clock on its arrival at A will be
1/2tv^2/c^2 second slow. Thence we conclude that a balance-clock at the
equator must go more slowly, by a very small amount, than a precisely
similar clock situated at one of the poles under otherwise identical
conditions.
/unquote
Therefore SRT is ridiculously assumptive and refutes itself logically, and
is refuted by Sagnac experimentally.
Let me know when you've woken up, you fell you off the wrong bandwagon.
[quote:e6003d0809]Very clever puzzle with the arrow scenario. Let us know when you've
worked it out.
[/quote:e6003d0809]
Not at all, it was a very simple puzzle.
In the frame of the train one arrow decelerates from v to zero in time t.
In time 2t one duellist is struck in the eye like poor old King Harold
at the battle of Battle (near Hastings) by William the Bastard, but by
the fletched end, not the pointy end.
It's rather like shooting the arrow straight up. What goes up must come
down, or so I'm told.
The answer is vt-1/2gt^2 = 0.
Solve for t or let us know when you've attended high school. |
|
|
| Back to top |
|
|
|
| ... |
| Posted: Sat Oct 17, 2009 2:23 am |
|
|
|
Guest
|
On Fri, 16 Oct 2009 15:35:46 -0400, Jonah Thomas <jethomas5 at (no spam) gmail.com>
wrote:
[quote:6adf78568e]tominlaguna at (no spam) yahoo.com wrote:
Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
Here is why I think there is something else going on too.
________________
/ \
\____x___________/
Here is the simple form of the Wang experiment, with the
emitter-detector x traveling around the loop. When x is on the linear
section traveling at constant speed they get the same phase shift that
they do when it is going around the rollers.
___________________________________
/ \
\____x______________________________/
When they change the length and change nothing else, they get a change
in phase shift proportional to the length. How has this changed the
acceleration proportional to the phase shift? Presumably the light is
getting accelerated when it goes around the rollers, but why is it more
acceleration because of the extra length? They tried a version where
there was no extra Sagnac-area enclosed, too.
The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration.
I think that's true, because it requires a closed path and how are you
going to get a closed path without changing the direction of the light?
And how can you do that with no acceleration? But I don't yet see that
the effect is proportional to the acceleration. It's proportional to the
linear speed and to the length of the moving fiber.
Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters.
Interesting! Did they measure whether the effect was the same in the
morning and evening?
While looking for Saburi I found this which may be of some interest:
http://adsabs.harvard.edu/full/1986IAUS..114..299A
[/quote:6adf78568e]
In the diagrams you have presented, it appears you are describing an
experiment shown in the earlier paper cited by Sue. Please look at
the paper I referenced; specifically Fig. 3. For that test, neither
the source nor the receiver was moving; it was only a straight section
of fiber that was translated. So you have: 4 meter (or whatever the
exact size was) loop of fiber, stationary source, stationary receiver,
yet a Sagnac signal generated when you move a section of the loop.
That seems to defy logic since light traveling in opposing directions
still has to cover the 4 meter distance each way while traveling at c;
same speed in each direction, same distance to travel, but different
arrival times. There is obviously a change in the optical path length
since the physical path length remains unchanged. I contend that is
produced by acceleration; similar to the way the bullet path length is
changed in the dueling analogy.
When I first thought about the reported results, I understood the
source of the fringe shift to be a change in the enclosed area. But
upon looking at the diagram and seeing the linearity of the plots, I
concluded that area change was not a factor, otherwise the data plot
would not be linear for the various tested speeds. Translational
speed by itself is not a factor just as it is not a factor in the
dueling analogy, where both shooters would die at the same time when
the train was moving at constant speed.
I have a copy of the Allan and Ashby paper you linked; unfortunately,
I do not have copies of either of Saburi's papers. Later today, Ron
Hatch will hold a webinar at NPA to discuss Ashby's relativistic views
on GPS and Sagnac. Though I'm not a fan of Ron's Lorentz ether
theory, it might be fun to watch him poke a finger in Ashby's eye. |
|
|
| Back to top |
|
|
|
| ... |
| Posted: Sat Oct 17, 2009 3:31 am |
|
|
|
Guest
|
On Sat, 17 Oct 2009 09:08:03 +0100, "Androcles"
<Headmaster at (no spam) Hogwarts.physics_p> wrote:
[quote:0f7ee1e140]
tominlaguna at (no spam) yahoo.com> wrote in message
news:iqoid5dngs6tslqd8muf4iabprhin6rot8 at (no spam) 4ax.com...
On Fri, 16 Oct 2009 16:39:37 +0100, "Androcles"
Headmaster at (no spam) Hogwarts.physics_p> wrote:
tominlaguna at (no spam) yahoo.com> wrote in message
news:to2hd5pm6nvm8qdul7kecjf5do7imn1ng5 at (no spam) 4ax.com...
I missed the opportunity to comment on this subject when a thread was
started by Jonah Thomas last month. I hope to continue the discussion
from this new starting point.
Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration. There are "Sagnac devices" that can detect
that phenomenon, but they should not be confused with the phenomenon
itself. Examples of the devices are: the passive Sagnac
interferometer devices of Sagnac, Pogany, Michelson-Gale, and
Dufour-Prunier; the active Sagnac interferometer devices of
Macek-Davis, Stedmann, modern laser gyros; and finally the "one-way"
Sagnac system of devices known as GPS.
A simple analogy of the phenomenon can be understood by this example:
Assume you have a long freight car, 100 feet long. There is a dueler
located at each end with identical guns, ammo and skill. If the car
is stationary with respect to the rails or moving at a constant
velocity and both fire their guns at the same time, they both die at
the same time. But, if the train happens to accelerate forward while
the bullets are in flight, the guy at the rear of the car dies first.
The same thing would occur if the car was experiencing acceleration
throughout the gun fight. That, in my opinion, is the phenomenon of
Sagnac. Bullets are flying in two directions covering an equal
distance of 100 feet, but one arrives sooner than the other due to the
acceleration of the receiver.
Paul Anderson was describing a type of device while he thought he was
describing the effect. The generalized Sagnac effect does not deal
with enclosed areas and angular velocity; several detection devices
are based on those criteria, but the phenomenon is not exclusive to
them. Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters. The GPS network is corrected each day to
adjust their clocks so that the one-way transmission of signals is
accurate due to the Sagnac effect. Paul also suggested the Wang
experiment was a modified Fizeau experiment. They used both hollow
fibers and solid cross-section fiber and got the same readings. Others
in the past, Pogany and Harress, investigated the use of glass prisms
in the Sagnac set-up to determine if it was a Fizeau effect, and they
concluded it was not. Post has written about this.
Tom Roberts erroneously states that the ballistic model cannot explain
Sagnac. I will acknowledge that the "re-emission" ballistic model is
denied by the Sagnac results. Tolman (1912) and Panofsky and Phillips
(1961) describe three ballistic models. Waldron (1977) describes two
of the three: the ballistic model of Ritz/Waldron and the re-emission
model. The re-emission model fails in explaining Sagnac and a host of
other experiments.
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v. all with respect to the mirror.
Regards,
Tom Miles
Correct. Very good analysis. One tiny flaw...
Newton's corpuscles of light model, today called photons, predates
Walter Ritz by 250 years.
Of course a FOG cannot in any way be related to Einstein's relativity,
since that specifically states light is always propagated in empty space
with a definite velocity c which is independent of the state of motion
of the emitting body and a FOG isn't empty space.
Hence Andersen's and Roberts' arguments are non sequitur.
For amusement only:
If the duellists shoot arrows at each other at v feet per second
and the train accelerates at g fps/second, how far apart should
the duellists be to guarantee one of them survives?
Yes also, on FOG not being related to Einstein's special relativity
(SRT). There are a number of people in a discussion group that I
belong to that insist that Sagnac and Michelson-Gale refute SRT. I
cannot get on that bandwagon because the Sagnac phenomenon resides
exclusively within accelerated FOR.
Sagnac isn't FOG and SRT says:
quote/
It is at once apparent that this result still holds good if the clock moves
from A to B in any polygonal line, and also when the points A and B
coincide.
If we assume that the result proved for a polygonal line is also valid for a
continuously curved line, we arrive at this result: If one of two
synchronous clocks at A is moved in a closed curve with constant velocity
until it returns to A, the journey lasting t seconds, then by the clock
which has remained at rest the travelled clock on its arrival at A will be
1/2tv^2/c^2 second slow. Thence we conclude that a balance-clock at the
equator must go more slowly, by a very small amount, than a precisely
similar clock situated at one of the poles under otherwise identical
conditions.
/unquote
Therefore SRT is ridiculously assumptive and refutes itself logically, and
is refuted by Sagnac experimentally.
Let me know when you've woken up, you fell you off the wrong bandwagon.
Very clever puzzle with the arrow scenario. Let us know when you've
worked it out.
Not at all, it was a very simple puzzle.
In the frame of the train one arrow decelerates from v to zero in time t.
In time 2t one duellist is struck in the eye like poor old King Harold
at the battle of Battle (near Hastings) by William the Bastard, but by
the fletched end, not the pointy end.
It's rather like shooting the arrow straight up. What goes up must come
down, or so I'm told.
The answer is vt-1/2gt^2 = 0.
Solve for t or let us know when you've attended high school.
Are you quoting from Ives?[/quote:0f7ee1e140]
Look, I agree with your positions on SRT and on the ballistic theory.
But I do not agree that Sagnac has anything to do with SRT. It is
logically inconsistent to take a phenomenon that is exclusive to
accelerating frames and somehow say it disproves a theory that is
exclusive to non-accelerating frames.
That is why I think the quote you provided in nonsense. Whoever
stated it was making an illogical connection: trying to explain the
results of an acceleration test using tools that are reserved for a
non-accelerating environment.
I am also at a loss with your statement that Sagnac isn't FOG. Can
you elaborate? As far as I am concerned the FOG device operates on
the same principle as the Sagnac device.
I didn't answer your clever puzzle because the answer was given in the
conditions. You asked for their distance; I stated at the outset that
they were 100 feet apart. Now, if you had asked for the duration of
the applied acceleration, I would have had something to work toward.
Your answer is correct, but for a different question. I went through
Battle recently while visiting Bodiam Castle. |
|
|
| Back to top |
|
|
|
| Dono.... |
| Posted: Sat Oct 17, 2009 4:56 am |
|
|
|
Guest
|
On Oct 16, 11:08 pm, tominlag... at (no spam) yahoo.com wrote:
[quote:3ee328f62b]On Fri, 16 Oct 2009 09:01:34 -0700 (PDT), "Dono." <sa... at (no spam) comcast.net
wrote:
On Oct 16, 8:43 am, tominlag... at (no spam) yahoo.com wrote:
On Fri, 16 Oct 2009 08:31:15 -0700 (PDT), "Dono." <sa... at (no spam) comcast.net
wrote:
On Oct 16, 8:08 am, tominlag... at (no spam) yahoo.com wrote:
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v… all with respect to the mirror.
Regards,
Tom Miles
If the speed is ANYTHING but c, the model fails BOTH the Sagnac and
the Ives experiments.
I suspect you are referring to the passive type of interferometer
devices. In that case, you are wrong: whatever the speed of the
initial ray of light, components going in each direction after
splitting will have the same speed, be it c or u. The outcome is the
same. As a practical matter, since the sources in the experiments you
cite are not in motion with respect to the device, the speed will be
c.
Prove it . Show the math.
I don't know what there is to prove. First, please let me know which
Ives experiment you are discussing.
[/quote:3ee328f62b]
Ives-Stilwell.
[quote:3ee328f62b]I was not aware of an Ives
experiment that tested the Sagnac effect.
[/quote:3ee328f62b]
Who told you that? I told you that all flavors of the ballistic theory
are disproved by the Ives experiment AND by the Sagnac experiment.
Prove that this isn't so.
[quote:3ee328f62b]The point I was trying to make was simply that whatever the speed of
the incoming ray was, that speed was retained by the two components
after the ray is split.
[/quote:3ee328f62b]
Irrelevant, you need to write the equations of the complete
experiment. If you ever manage to do that (I doubt it), you will find
out that you are wrong: Ives, Sagnac, Fizeau experiments all falsify
the ballistic theory. So does MMX in a medium with refraction greater
than 1. |
|
|
| Back to top |
|
|
|
| Androcles... |
| Posted: Sat Oct 17, 2009 5:21 am |
|
|
|
Guest
|
<tominlaguna at (no spam) yahoo.com> wrote in message
news:9t1jd51dievuut8il5veq9lc0d1j034pbo at (no spam) 4ax.com...
[quote:7054e4eeee]On Sat, 17 Oct 2009 09:08:03 +0100, "Androcles"
Headmaster at (no spam) Hogwarts.physics_p> wrote:
tominlaguna at (no spam) yahoo.com> wrote in message
news:iqoid5dngs6tslqd8muf4iabprhin6rot8 at (no spam) 4ax.com...
On Fri, 16 Oct 2009 16:39:37 +0100, "Androcles"
Headmaster at (no spam) Hogwarts.physics_p> wrote:
tominlaguna at (no spam) yahoo.com> wrote in message
news:to2hd5pm6nvm8qdul7kecjf5do7imn1ng5 at (no spam) 4ax.com...
I missed the opportunity to comment on this subject when a thread was
started by Jonah Thomas last month. I hope to continue the discussion
from this new starting point.
Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration. There are "Sagnac devices" that can detect
that phenomenon, but they should not be confused with the phenomenon
itself. Examples of the devices are: the passive Sagnac
interferometer devices of Sagnac, Pogany, Michelson-Gale, and
Dufour-Prunier; the active Sagnac interferometer devices of
Macek-Davis, Stedmann, modern laser gyros; and finally the "one-way"
Sagnac system of devices known as GPS.
A simple analogy of the phenomenon can be understood by this example:
Assume you have a long freight car, 100 feet long. There is a dueler
located at each end with identical guns, ammo and skill. If the car
is stationary with respect to the rails or moving at a constant
velocity and both fire their guns at the same time, they both die at
the same time. But, if the train happens to accelerate forward while
the bullets are in flight, the guy at the rear of the car dies first.
The same thing would occur if the car was experiencing acceleration
throughout the gun fight. That, in my opinion, is the phenomenon of
Sagnac. Bullets are flying in two directions covering an equal
distance of 100 feet, but one arrives sooner than the other due to the
acceleration of the receiver.
Paul Anderson was describing a type of device while he thought he was
describing the effect. The generalized Sagnac effect does not deal
with enclosed areas and angular velocity; several detection devices
are based on those criteria, but the phenomenon is not exclusive to
them. Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters. The GPS network is corrected each day to
adjust their clocks so that the one-way transmission of signals is
accurate due to the Sagnac effect. Paul also suggested the Wang
experiment was a modified Fizeau experiment. They used both hollow
fibers and solid cross-section fiber and got the same readings. Others
in the past, Pogany and Harress, investigated the use of glass prisms
in the Sagnac set-up to determine if it was a Fizeau effect, and they
concluded it was not. Post has written about this.
Tom Roberts erroneously states that the ballistic model cannot explain
Sagnac. I will acknowledge that the "re-emission" ballistic model is
denied by the Sagnac results. Tolman (1912) and Panofsky and Phillips
(1961) describe three ballistic models. Waldron (1977) describes two
of the three: the ballistic model of Ritz/Waldron and the re-emission
model. The re-emission model fails in explaining Sagnac and a host of
other experiments.
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v. all with respect to the mirror.
Regards,
Tom Miles
Correct. Very good analysis. One tiny flaw...
Newton's corpuscles of light model, today called photons, predates
Walter Ritz by 250 years.
Of course a FOG cannot in any way be related to Einstein's relativity,
since that specifically states light is always propagated in empty space
with a definite velocity c which is independent of the state of motion
of the emitting body and a FOG isn't empty space.
Hence Andersen's and Roberts' arguments are non sequitur.
For amusement only:
If the duellists shoot arrows at each other at v feet per second
and the train accelerates at g fps/second, how far apart should
the duellists be to guarantee one of them survives?
Yes also, on FOG not being related to Einstein's special relativity
(SRT). There are a number of people in a discussion group that I
belong to that insist that Sagnac and Michelson-Gale refute SRT. I
cannot get on that bandwagon because the Sagnac phenomenon resides
exclusively within accelerated FOR.
Sagnac isn't FOG and SRT says:
quote/
It is at once apparent that this result still holds good if the clock
moves
from A to B in any polygonal line, and also when the points A and B
coincide.
If we assume that the result proved for a polygonal line is also valid for
a
continuously curved line, we arrive at this result: If one of two
synchronous clocks at A is moved in a closed curve with constant velocity
until it returns to A, the journey lasting t seconds, then by the clock
which has remained at rest the travelled clock on its arrival at A will be
1/2tv^2/c^2 second slow. Thence we conclude that a balance-clock at the
equator must go more slowly, by a very small amount, than a precisely
similar clock situated at one of the poles under otherwise identical
conditions.
/unquote
Therefore SRT is ridiculously assumptive and refutes itself logically, and
is refuted by Sagnac experimentally.
Let me know when you've woken up, you fell you off the wrong bandwagon.
Very clever puzzle with the arrow scenario. Let us know when you've
worked it out.
Not at all, it was a very simple puzzle.
In the frame of the train one arrow decelerates from v to zero in time t.
In time 2t one duellist is struck in the eye like poor old King Harold
at the battle of Battle (near Hastings) by William the Bastard, but by
the fletched end, not the pointy end.
It's rather like shooting the arrow straight up. What goes up must come
down, or so I'm told.
The answer is vt-1/2gt^2 = 0.
Solve for t or let us know when you've attended high school.
Are you quoting from Ives?
[/quote:7054e4eeee]
No, I'm quoting Einstein, straight from the horse's arse. I have no
reason to quote the tail wagging the dog. Here, see for yourself:
http://www.fourmilab.ch/etexts/einstein/specrel/www/
[quote:7054e4eeee]Look, I agree with your positions on SRT and on the ballistic theory.
But I do not agree that Sagnac has anything to do with SRT. It is
logically inconsistent to take a phenomenon that is exclusive to
accelerating frames and somehow say it disproves a theory that is
exclusive to non-accelerating frames.
[/quote:7054e4eeee]
Sorry to disappoint you, but this analysis
http://www.mathpages.com/rr/s2-07/2-07.htm
is isomorphic to Einstein's lunatic "thought experiment":
Both contain the same blunder, namely, there are two angles alpha
and -alpha, not one, as shown here,
http://www.androcles01.pwp.blueyonder.co.uk/Sagnac/SagnacIdiocy.htm
and in Einstein's thought experiment the ray returns to vt,
1/2 [ tau(0,0,0,t) + tau(vt,0,0,t+x'/(c+v)+x'/(c-v))] = tau(x',0,0, t+
x'/(c-v))
not 0 as his inequality claims here:
http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img22.gif
Einstein's thought experiment is wrapped around the perimeter of
a circle in Sagnac's real experiment and of course no time dilation
occurs or your wristwatch would slow down if you stood watching
things turn.
[quote:7054e4eeee]That is why I think the quote you provided in nonsense.
[/quote:7054e4eeee]
Take it up with Einstein, those are his words. I've always said
his paper was nonsense, but there are a bunch of cranks trying
to build a supercollider with my taxes that rely on his drivel.
[quote:7054e4eeee]Whoever
stated it was making an illogical connection: trying to explain the
results of an acceleration test using tools that are reserved for a
non-accelerating environment.
[/quote:7054e4eeee]
Again, take it up with Einstein, he's the one that said
"If we assume that the result proved for a polygonal line is also valid
for a continuously curved line"...
Perhaps you'd care to elaborate on why a continuous curve isn't an
accelerating environment or where Einstein said accelerating
environments were not allowed.
[quote:7054e4eeee]I am also at a loss with your statement that Sagnac isn't FOG. Can
you elaborate?
[/quote:7054e4eeee]
Sure can. FOG stands "Fibre Optic Gyroscope" and optical fibres
hadn't been invented in 1913 when Sagnac performed his experiment.
http://commons.wikimedia.org/wiki/File:Sagnac-Interferometer.png
[quote:7054e4eeee]As far as I am concerned the FOG device operates on
the same principle as the Sagnac device.
[/quote:7054e4eeee]
As far as I'm concerned Sagnac disproves SRT and you haven't
so much as read SRT to know what it says.
[quote:7054e4eeee]I didn't answer your clever puzzle because the answer was given in the
conditions. You asked for their distance; I stated at the outset that
they were 100 feet apart.
[/quote:7054e4eeee]
It wasn't my clever puzzle, it was your clever but inappropriate attempt
to apply acceleration to a constant angular velocity.
I made your clever irrelevant puzzle algebraic and said it was for
amusement only, changing from guns to bows and arrows. I'm
amused that you ducked it, thus verifying my prophecy. :-)
[quote:7054e4eeee]Now, if you had asked for the duration of
the applied acceleration, I would have had something to work toward.
[/quote:7054e4eeee]
As I understood your question, the duration of the applied acceleration
was undefined. The crank Einstein made a big deal out of acceleration
and gravity, muttering "Principle of Equivalence". As far as I'm aware,
gravity is not about to be turned off with the upcoming postal strike.
The distance is vt. If that is 100 ft, and g = 32 fps/s, what is the twang
velocity of the bowstring? Remember that one duellist is guaranteed
to survive.
[quote:7054e4eeee]Your answer is correct, but for a different question. I went through
Battle recently while visiting Bodiam Castle.
[/quote:7054e4eeee]
How unfortunate for you. All the blood and gore has long since been
cleaned up, nothing left to see. Coming all the way from Laguna in
Southern Thailand , too... what a shame. |
|
|
| Back to top |
|
|
|
| Jonah Thomas... |
| Posted: Sat Oct 17, 2009 7:33 am |
|
|
|
Guest
|
tominlaguna at (no spam) yahoo.com wrote:
[quote:5cc1963c92]Jonah Thomas <jethomas5 at (no spam) gmail.com> wrote:
tominlaguna at (no spam) yahoo.com wrote:
Sue posted a link to a Wang & et al paper which describes their
fiber> optical gyro (FOG) experiments. That paper has been
superseded by:> http://arxiv.org/ftp/physics/papers/0609/0609235.pdf.
This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of
the> FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that
Dr.> Wang has demonstrated that his design can detect translational
motion.> I disagree. They measured the acceleration of the fiber
section from> zero to some constant velocity.
Here is why I think there is something else going on too.
________________
/ \
\____x___________/
Here is the simple form of the Wang experiment, with the
emitter-detector x traveling around the loop. When x is on the linear
section traveling at constant speed they get the same phase shift
that they do when it is going around the rollers.
___________________________________
/ \
\____x______________________________/
When they change the length and change nothing else, they get a
change in phase shift proportional to the length. How has this
changed the acceleration proportional to the phase shift? Presumably
the light is getting accelerated when it goes around the rollers, but
why is it more acceleration because of the extra length? They tried a
version where there was no extra Sagnac-area enclosed, too.
The Wang paper has lead me to conclude that the "Sagnac effect" is
a> phenomenon peculiar to situations when the source and/or receiver
are> experiencing acceleration.
I think that's true, because it requires a closed path and how are
you going to get a closed path without changing the direction of the
light? And how can you do that with no acceleration? But I don't yet
see that the effect is proportional to the acceleration. It's
proportional to the linear speed and to the length of the moving
fiber.
In the diagrams you have presented, it appears you are describing an
experiment shown in the earlier paper cited by Sue. Please look at
the paper I referenced; specifically Fig. 3. For that test, neither
the source nor the receiver was moving; it was only a straight section
of fiber that was translated. So you have: 4 meter (or whatever the
exact size was) loop of fiber, stationary source, stationary receiver,
yet a Sagnac signal generated when you move a section of the loop.
That seems to defy logic since light traveling in opposing directions
still has to cover the 4 meter distance each way while traveling at c;
same speed in each direction, same distance to travel, but different
arrival times. There is obviously a change in the optical path length
since the physical path length remains unchanged. I contend that is
produced by acceleration; similar to the way the bullet path length is
changed in the dueling analogy.
[/quote:5cc1963c92]
I can easily believe that you are talking about something that was
produced by a change in acceleration.
But the effect that I pointed out from the first paper does not appear
to me to have different acceleration, and yet they got a phase
difference. So I think there is something other than acceleration going
on to get the Wang effect. Or possibly there is a hidden acceleration
that I haven't noticed. Maybe somehow if you use rollers with the same
radius rotating at the same speed, it puts a bigger acceleration on the
fiber if the fiber is a longer length?
[quote:5cc1963c92]When I first thought about the reported results, I understood the
source of the fringe shift to be a change in the enclosed area. But
upon looking at the diagram and seeing the linearity of the plots, I
concluded that area change was not a factor, otherwise the data plot
would not be linear for the various tested speeds.
[/quote:5cc1963c92]
Agreed.
[quote:5cc1963c92]Translational speed by itself is not a factor just as it is not a
factor in the dueling analogy, where both shooters would die at the
same time when the train was moving at constant speed.
[/quote:5cc1963c92]
Translational speed looks like a factor in the one I mentioned, once you
accept that area is not a factor. |
|
|
| Back to top |
|
|
|
| ... |
| Posted: Sat Oct 17, 2009 10:09 am |
|
|
|
Guest
|
On Sat, 17 Oct 2009 12:21:32 +0100, "Androcles"
<Headmaster at (no spam) Hogwarts.physics_p> wrote:
[quote:3b0cbf32ed]
tominlaguna at (no spam) yahoo.com> wrote in message
news:9t1jd51dievuut8il5veq9lc0d1j034pbo at (no spam) 4ax.com...
On Sat, 17 Oct 2009 09:08:03 +0100, "Androcles"
Headmaster at (no spam) Hogwarts.physics_p> wrote:
tominlaguna at (no spam) yahoo.com> wrote in message
news:iqoid5dngs6tslqd8muf4iabprhin6rot8 at (no spam) 4ax.com...
On Fri, 16 Oct 2009 16:39:37 +0100, "Androcles"
Headmaster at (no spam) Hogwarts.physics_p> wrote:
tominlaguna at (no spam) yahoo.com> wrote in message
news:to2hd5pm6nvm8qdul7kecjf5do7imn1ng5 at (no spam) 4ax.com...
I missed the opportunity to comment on this subject when a thread was
started by Jonah Thomas last month. I hope to continue the discussion
from this new starting point.
Sue posted a link to a Wang & et al paper which describes their fiber
optical gyro (FOG) experiments. That paper has been superseded by:
http://arxiv.org/ftp/physics/papers/0609/0609235.pdf. This latest
paper provides a more detailed account of that work.
Figure 3 of the new Wang paper shows that when a linear section of the
FOG is moved in translation, there is a fringe shift that is
proportional to the length of that section and the speed of its
motion. Most people that I have discussed this with believe that Dr.
Wang has demonstrated that his design can detect translational motion.
I disagree. They measured the acceleration of the fiber section from
zero to some constant velocity.
The Wang paper has lead me to conclude that the "Sagnac effect" is a
phenomenon peculiar to situations when the source and/or receiver are
experiencing acceleration. There are "Sagnac devices" that can detect
that phenomenon, but they should not be confused with the phenomenon
itself. Examples of the devices are: the passive Sagnac
interferometer devices of Sagnac, Pogany, Michelson-Gale, and
Dufour-Prunier; the active Sagnac interferometer devices of
Macek-Davis, Stedmann, modern laser gyros; and finally the "one-way"
Sagnac system of devices known as GPS.
A simple analogy of the phenomenon can be understood by this example:
Assume you have a long freight car, 100 feet long. There is a dueler
located at each end with identical guns, ammo and skill. If the car
is stationary with respect to the rails or moving at a constant
velocity and both fire their guns at the same time, they both die at
the same time. But, if the train happens to accelerate forward while
the bullets are in flight, the guy at the rear of the car dies first.
The same thing would occur if the car was experiencing acceleration
throughout the gun fight. That, in my opinion, is the phenomenon of
Sagnac. Bullets are flying in two directions covering an equal
distance of 100 feet, but one arrives sooner than the other due to the
acceleration of the receiver.
Paul Anderson was describing a type of device while he thought he was
describing the effect. The generalized Sagnac effect does not deal
with enclosed areas and angular velocity; several detection devices
are based on those criteria, but the phenomenon is not exclusive to
them. Saburi in 1976 demonstrated that there was a radio signal
transit time difference east-west between two earth-stationary
receiver/transmitters. The GPS network is corrected each day to
adjust their clocks so that the one-way transmission of signals is
accurate due to the Sagnac effect. Paul also suggested the Wang
experiment was a modified Fizeau experiment. They used both hollow
fibers and solid cross-section fiber and got the same readings. Others
in the past, Pogany and Harress, investigated the use of glass prisms
in the Sagnac set-up to determine if it was a Fizeau effect, and they
concluded it was not. Post has written about this.
Tom Roberts erroneously states that the ballistic model cannot explain
Sagnac. I will acknowledge that the "re-emission" ballistic model is
denied by the Sagnac results. Tolman (1912) and Panofsky and Phillips
(1961) describe three ballistic models. Waldron (1977) describes two
of the three: the ballistic model of Ritz/Waldron and the re-emission
model. The re-emission model fails in explaining Sagnac and a host of
other experiments.
In the Ritz/Waldron model, a mirror is not a new source, and therefore
light may or may not be reflected at c with respect to it. Its speed
after reflection is based on any relative motion between the source
and the mirror. If there is no relative motion, the reflected photon
will be moving at c; if there is relative motion, v, its speed will be
c +/- v. all with respect to the mirror.
Regards,
Tom Miles
Correct. Very good analysis. One tiny flaw...
Newton's corpuscles of light model, today called photons, predates
Walter Ritz by 250 years.
Of course a FOG cannot in any way be related to Einstein's relativity,
since that specifically states light is always propagated in empty space
with a definite velocity c which is independent of the state of motion
of the emitting body and a FOG isn't empty space.
Hence Andersen's and Roberts' arguments are non sequitur.
For amusement only:
If the duellists shoot arrows at each other at v feet per second
and the train accelerates at g fps/second, how far apart should
the duellists be to guarantee one of them survives?
Yes also, on FOG not being related to Einstein's special relativity
(SRT). There are a number of people in a discussion group that I
belong to that insist that Sagnac and Michelson-Gale refute SRT. I
cannot get on that bandwagon because the Sagnac phenomenon resides
exclusively within accelerated FOR.
Sagnac isn't FOG and SRT says:
quote/
It is at once apparent that this result still holds good if the clock
moves
from A to B in any polygonal line, and also when the points A and B
coincide.
If we assume that the result proved for a polygonal line is also valid for
a
continuously curved line, we arrive at this result: If one of two
synchronous clocks at A is moved in a closed curve with constant velocity
until it returns to A, the journey lasting t seconds, then by the clock
which has remained at rest the travelled clock on its arrival at A will be
1/2tv^2/c^2 second slow. Thence we conclude that a balance-clock at the
equator must go more slowly, by a very small amount, than a precisely
similar clock situated at one of the poles under otherwise identical
conditions.
/unquote
Therefore SRT is ridiculously assumptive and refutes itself logically, and
is refuted by Sagnac experimentally.
Let me know when you've woken up, you fell you off the wrong bandwagon.
Very clever puzzle with the arrow scenario. Let us know when you've
worked it out.
Not at all, it was a very simple puzzle.
In the frame of the train one arrow decelerates from v to zero in time t.
In time 2t one duellist is struck in the eye like poor old King Harold
at the battle of Battle (near Hastings) by William the Bastard, but by
the fletched end, not the pointy end.
It's rather like shooting the arrow straight up. What goes up must come
down, or so I'm told.
The answer is vt-1/2gt^2 = 0.
Solve for t or let us know when you've attended high school.
Are you quoting from Ives?
No, I'm quoting Einstein, straight from the horse's arse. I have no
reason to quote the tail wagging the dog. Here, see for yourself:
http://www.fourmilab.ch/etexts/einstein/specrel/www/
Look, I agree with your positions on SRT and on the ballistic theory.
But I do not agree that Sagnac has anything to do with SRT. It is
logically inconsistent to take a phenomenon that is exclusive to
accelerating frames and somehow say it disproves a theory that is
exclusive to non-accelerating frames.
Sorry to disappoint you, but this analysis
http://www.mathpages.com/rr/s2-07/2-07.htm
is isomorphic to Einstein's lunatic "thought experiment":
Both contain the same blunder, namely, there are two angles alpha
and -alpha, not one, as shown here,
http://www.androcles01.pwp.blueyonder.co.uk/Sagnac/SagnacIdiocy.htm
and in Einstein's thought experiment the ray returns to vt,
1/2 [ tau(0,0,0,t) + tau(vt,0,0,t+x'/(c+v)+x'/(c-v))] = tau(x',0,0, t+
x'/(c-v))
not 0 as his inequality claims here:
http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img22.gif
Einstein's thought experiment is wrapped around the perimeter of
a circle in Sagnac's real experiment and of course no time dilation
occurs or your wristwatch would slow down if you stood watching
things turn.
That is why I think the quote you provided in nonsense.
Take it up with Einstein, those are his words. I've always said
his paper was nonsense, but there are a bunch of cranks trying
to build a supercollider with my taxes that rely on his drivel.
Whoever
stated it was making an illogical connection: trying to explain the
results of an acceleration test using tools that are reserved for a
non-accelerating environment.
Again, take it up with Einstein, he's the one that said
"If we assume that the result proved for a polygonal line is also valid
for a continuously curved line"...
Perhaps you'd care to elaborate on why a continuous curve isn't an
accelerating environment or where Einstein said accelerating
environments were not allowed.
I am also at a loss with your statement that Sagnac isn't FOG. Can
you elaborate?
Sure can. FOG stands "Fibre Optic Gyroscope" and optical fibres
hadn't been invented in 1913 when Sagnac performed his experiment.
http://commons.wikimedia.org/wiki/File:Sagnac-Interferometer.png
As far as I am concerned the FOG device operates on
the same principle as the Sagnac device.
As far as I'm concerned Sagnac disproves SRT and you haven't
so much as read SRT to know what it says.
I didn't answer your clever puzzle because the answer was given in the
conditions. You asked for their distance; I stated at the outset that
they were 100 feet apart.
It wasn't my clever puzzle, it was your clever but inappropriate attempt
to apply acceleration to a constant angular velocity.
I made your clever irrelevant puzzle algebraic and said it was for
amusement only, changing from guns to bows and arrows. I'm
amused that you ducked it, thus verifying my prophecy. :-)
Now, if you had asked for the duration of
the applied acceleration, I would have had something to work toward.
As I understood your question, the duration of the applied acceleration
was undefined. The crank Einstein made a big deal out of acceleration
and gravity, muttering "Principle of Equivalence". As far as I'm aware,
gravity is not about to be turned off with the upcoming postal strike.
The distance is vt. If that is 100 ft, and g = 32 fps/s, what is the twang
velocity of the bowstring? Remember that one duellist is guaranteed
to survive.
[/quote:3b0cbf32ed]
I calculate the twang velocity at 87.5 fps when I assume that the
foreward archer's heart is 5 feet above the floor and he is wearing
steel-tipped shoes.
[quote:3b0cbf32ed]Your answer is correct, but for a different question. I went through
Battle recently while visiting Bodiam Castle.
How unfortunate for you. All the blood and gore has long since been
cleaned up, nothing left to see. Coming all the way from Laguna in
Southern Thailand , too... what a shame.
[/quote:3b0cbf32ed]
Actually, I am living in the UK these days. I kept the Laguna Beach,
CA email address as a matter of convenience.
More tomorrow. |
|
|
| Back to top |
|
|
|
|
|
All times are GMT - 5 Hours
The time now is Mon Dec 14, 2009 3:37 pm
|
|