zotero-db/storage/KPDK6GI9/.zotero-ft-cache

March/April 2005

GALILEAN ELECTRODYNAMICS

23

First-Order Fiber-Interferometric Experiments for Crucial Test of Light-Speed Constancy*
Ruyong Wang St. Cloud State University, St. Cloud, Minnesota 56301, USA
e-mail: ruwang@stcloudstate.edu
The Michelson-Morley experiment for examining light-speed constancy in paths moving linearly is second-order in speed, so it has never been conducted with paths moving relative to Earth. The Sagnac experiment is a first-order experiment, but it does not address motion that is linear, since its path motion is caused by rotation. The design of an interferometric experiment that is not only sensitive to linear motion, but also first-order in speed, needs two features: 1) optical paths in uniform translational motion, and 2) paths for light return without cancellation of possible effects. Two arrangements with these features are here presented: a conveyor-like arrangement, and a shearing parallelogram arrangement. Both can be implemented with fiber-optic technology. If the entire optical loop is fiber, the light-speed constancy in a moving path of the fiber is examined; if the fiber loop is broken to leave a gap of vacuum (or air), the light-speed constancy in a moving path of vacuum (or air) is examined. According to the same analysis as that for a fiber-optic gyro, translational motion in these arrangements will lead to an increase of optical path length and an increase of the travel time difference, a result falsifying the principle of the light-speed constancy.
* Submitted 29 September 2001, accepted 6 December 2001, final revision June 2003.

Introduction

The Sagnac effect [1] shows that in a rotating closed optical

path, two counter-propagating light beams take different time

intervals to travel the path. For example, when the path rotates

counterclockwise, the beam propagating counterclockwise will

take a longer time interval than the beam propagating clockwise,

and vise versa. The time difference between them is given gener-

ally by

(Fig. 1a; the path is a quadrilateral, S is the

area of the quadrilateral, and Ω is the angular velocity of the ro-

tation) or for a circle

(Fig. 1b; the path is a circle, the

area of the circle is , is the speed of the circular mo-

tion, and is the circumference

of the circle). The Sagnac

effect is a first-order effect; that is, the time difference is pro-

portional to

. The Sagnac effect is an experimental fact

with sound foundation and numerous applications, including

highly precise fiber-optic gyros (FOG’s) [2]. However, the ex-

perimental fact becomes controversial when one attempts to rec-

oncile it with the principle of light-speed constancy in Special

Relativity Theory (SRT). Some argue that the Sagnac effect is

incompatible with light-speed constancy, because, for an ob-

server moving with the closed path, two counter-propagating

light beams would travel through paths with the same length,

and since their travel times differ, their speeds must differ. Oth-

ers, however, point out that in the Sagnac effect, the motion that

causes the light speed difference is uniform circular, not uniform

translational, as required for application of SRT. Therefore, the

Sagnac effect remains an unsolved fundamental problem in

physics [3]. So the Sagnac experiment cannot be considered a

crucial experiment to test the principle of the light-speed con-

stancy.

Ω

Ω

R

v

detector

source

beam *

splitter

1b.

1a.

Figure 1. The Sagnac experiment.

In order to have a crucial test for light-speed constancy, the path in uniform circular motion must be changed to a path in uniform translational motion. Interferometric experiments with paths in translational motion have existed for a long time, and among them, the Michelson-Morley experiment is the most important. However, the Michelson-Morley experiment is secondorder; i.e., the time difference possible in the experiment is

proportional to

, where is the translational speed of the

apparatus. Because of that, the existence or absence of the time

difference can only be determined when the translational speed

is very high. For example, an airplane, with its speed of about

300 m/s, would not be fast enough to tell whether or not light

speed is constant in a path moving relative to Earth. A real test

needs a Michelson-Morley type experiment in system moving

fast relative to Earth; e.g., a space shuttle [4]. So far, no one has

conducted such an experiment. Therefore, the assertion that

light speed is still in a system moving translationally relative

to Earth has not yet been verified.

24

Wang: Fiber-Interferometric Experiments

Vol. 16, No. 2

Obviously, if we could have an interferometric experiment that would be not only a crucial for linear motion as the Michelson-Morley experiment is, but also first-order like the Sagnac experiment is, we could more easily conduct the experiment to check whether or not light speed is constant when the path is in translational motion relative to Earth. A crucial first-order experiment using atomic clocks has been proposed [5], but a crucial first-order interferometric experiment would be much superior because an interferometer can easily detect a time difference shorter than the period of a light wave of several femtoseconds.

Experiment Design Requirements

To design a first-order crucial experiment, we should analyze why the Sagnac experiment is first-order while the MichelsonMorley experiment is second-order. The Sagnac experiment is first-order because in its arrangement, when the closed path rotates, one of the two beams always propagates in the same direction as the rotation (Fig. 2a), while the other beam always propagates in the direction opposite to the rotation. The result is that the effect of the travel-time difference between two beams along the path is always augmented, and never cancelled, and the final

effect is proportional to

. In the Michelson-Morley ex-

periment, the closed path moves purely translationally. It is im-

possible for a beam to propagate in the same direction as transla-

tional motion over the whole path: if in one part of the path, a

light beam propagates in the same direction as the motion, then

in another part of the path, the beam must propagate in the op-

posite direction (Fig. 2b). The effects along these two parts tend

to cancel each other, and lead to the final residual effect being

proportional to

.

v

v

beam

Ω

source splitter

* v

detector

2a.

2b.

Figure 2. The Sagnac experiment is first-order and the

Michelson-Morley experiment is second-order.

These facts show that designing a crucial first-order interferometric experiment involves two features: 1) optical paths in uniform translational motion, and 2) paths for light return without cancellation of possible effects. These features are possible to achieve, so long as not all paths in the arrangement are required to be translational. We have designed two viable arrangements. In the first arrangement, the circular path in a Sagnac experiment is divided into two half-circle paths, and two paths in translational motion are added. This results in a conveyor-like path (Fig. 3a). In this arrangement, a light beam is also divided by a

beam splitter into two beams, one of which propagates in the same direction as the motion of the path, while the other propagates against the motion of the path. In the second arrangement, the path is a shearing parallelogram with top and bottom counter-moving paths, or with a top moving path and a bottom stationary path (Fig. 3b). In this arrangement, a light beam in the top moving path can return in the bottom path without weakening the possible effect. These two arrangements can be implemented with fiber technology, and they have translationally moving paths, which are the means of conducting a crucial firstorder experiment to test the principle of the light-speed constancy.

v

v

v

v

v v

v stationary

3a.

3b.

Figure 3. Two arrangements for the first-order experiment: a)

conveyor-like arrangement and b) shearing parallelogram.

Experiments with Fiber-Optic Conveyors

The conveyor experiment is to be conducted by winding an optical fiber to a small conveyor instead of a cylindrical coil, and thus transforming a FOG into a fiber-optic conveyor (FOC) (Fig.

4). In a FOG, the Sagnac effect of one turn,

, is further strengthened when two counter-propagating

light beams travel one turn after another through a long fiber

loop wound around the coil multiple times. The total time differ-

ence for a FOG is given by

where N

is the number of fiber turns around the loop. In short, the Sagnac

effect scales with path length.

It is expected that in a FOC also, the effect scales with path

length. To avoid some possible biases in conducting the crucial

experiment with a FOC, we can use two FOC’s with the same

conveying speed , the same half-circle radius, but different path

lengths in translational motion: one with a length of and the

other with an extra length of (Fig. 5). The total travel time for

a beam going through a whole path consisting of several segments is the summation of the travel-time intervals through each

segment, ,

. The travel-time difference be-

tween two beams through the whole path is the summation of all the travel-time differences between two beams in each segment,
. Then the two travel-time differences,

and , of the two fiber-optic conveyors can be compared. The difference between the paths in the two conveyors is just the added paths with a length of in the second conveyor. Thus, if

March/April 2005

GALILEAN ELECTRODYNAMICS

25

the experiment shows that

, it proves that the added

two uniformly moving paths with the length do not contribute

towards the travel-time difference, and therefore, the two counter-propagating light beams have the same speed in these

paths. If the experiment shows that

, it means that in

the added uniformly moving paths, the two counter-propagating light beams have different speeds.

This result shows that the difference in travel times for a turn is

, and the total travel-time difference for a loop with

N turns is

. This result also shows that a fiber arc

having definite length and definite speed will contribute

to the total travel-time difference of the FOG, no matter how big the radius of the arc is.

cCouopulperler soSuorucrece

dDeteetcetcotror v v

l11 vv v

cCoouupplelrer Ddeetteecctotor r

v v
Ssoouurrccee

Figure 4. TFriagnusrfeor4m.inTgraanfsibfoerr-mopintigc gayrfoibinetrooapftiibcer-optic gyro into a fiber optic conveyer.
conveyor.

Analysis of Light Propagation in a FOG

We need to analyze what the expected change of the traveltime difference in a FOC would be when the two moving paths are added. To approach this problem, let us first examine how it is treated for the FOG. In [6], the propagation of light beams in a FOG is analyzed based on the Fizeau experiment [7] for light speeds in a moving medium. According to this experiment, for a stationary observer and counterclockwise rotation of a medium with refractive index (Fig. 6a), the light speeds in the medium for counterclockwise and clockwise propagations are

and

. For this sta-

tionary observer, a fiber segment is moving with speed and if the time interval for a counterclockwise light beam traveling

through is , then the fiber segment will move coun-

terclockwise a distance of

in this time interval. Therefore,

the counterclockwise beam will travel a total distance of

. Then we have

. Thus

. Similarly, if the time

interval for a clockwise light beam traveling through is ,

the fiber segment will move counterclockwise a distance of

in this time interval. Therefore, the clockwise beam will

travel a distance of

. Then, we have

.

Therefore obtain

. Finally, we

ll11/22

ll0

l11//22

vv vv

ll22 = l11++ ll00 vv vv
v

FanicFdgdoiiufgn∆rfueevtr2re5ee,y.no5eCfc.retoswCsmw,oop∆mifatithrbp1ienadargri-nifontdfpwegt∆roiecttwtn2cr,toaoonvcftevorletaniwynvvogeoerlytsifinimiwnbgegiettrhdileimodfnfpieefgtrfiteechrnescn.ets,co∆nt1-
veying lengths.

cccw ccw

v

v

∆l

6a.

c+ c∆l 6b.

Figure 6. Light propagation in a fiber-optic gyro and in a fiber-optic conveyor.

Light Propagation in a FOC
Now let us analyze the propagation of a light beam in a FOC. For the parts of the path in translational motion, we utilize the same analysis as for a FOG. In fact, that analysis is more suitable

26

Wang: Fiber-Interferometric Experiments

Vol. 16, No. 2

to this case than to a FOG, because in the Fizeau experiment the medium was moving translationally, and the added paths in a FOC are also moving translationally.
According to the Fizeau experiment, in a small segment of fiber of the added paths, the light speeds in a moving medium

are given for a stationary observer by

and

, where + denotes a light beam trav-

eling in the same direction as the motion of the path and – de-

notes a light beam traveling opposite to the motion of the path.

For this stationary observer, fiber segment is moving with speed v, and if the time interval for a light beam traveling in the

same direction as the motion of the path through is , then

the fiber segment will move a distance of in this time

interval (Fig. 6b). Therefore, this beam will travel a total distance

of

. Then, we have

. Thus

. Similarly, for a light beam traveling opposite the motion of the path, we have

. Finally, we obtain

, and apparently, the vertical component will not

cause any effect. Because

is constant, we can conclude that

because of the rotation of Earth, the two added paths with a length of and N turns will contribute an additional time differ-

ence of

.

VE

7a. ∆l

v'r

vr

θ ΩE

R

7b.
Figure 7. The effects caused by the rotation of Earth.

Since this segment is the same as any other segment of added paths, it is expected that the added uniformly moving paths will contribute a travel-time difference of

to the total travel-time difference; that is,

(or

if there are turns). This

means that if their lengths are the same, a path in uniform trans-

lational motion will contribute the same time difference to the

total travel-time difference as a path in uniform circular motion.

This means that light speed is not constant, not only when the

path is in uniform circular motion, but also when the path is in

uniform translation motion, a result falsifying the light-speed

constancy in moving paths of fiber.

Effects Caused by Earth Rotation

Since a FOG responses to the rotation of Earth, we should examine how a FOC responses to the rotation of Earth. We should, especially, examine the effect of the rotation of Earth to the added two paths in translational motion in the FOC experiment. The rotation of Earth will cause an additional translational mo-

tion with a speed of and an additional rotational motion with

an angular velocity of to the added two paths. Since the two

paths have the same additional translational motion, their effects will weaken each other and there will not be a net first-order effect (Fig. 7a). However, the additional rotational motion is different. It causes the two paths moving in opposite directions and there will be a net first-order effect (Fig. 7b). Let us examine a fiber segment . Its velocity caused by the rotation of Earth is

, and the horizontal component of the velocity

in the direction of the path is

. According to

the analysis mentioned above, the horizontal component

will contribute an additional time difference

Examining Light-speed Constancy in Vacuum (or Air) with FOC’s

It should be noted that the travel-time difference on the FOC

is not related to the refractive index . This means that if the

experiment were conducted in vacuum (

), the same result

would be expected. Furthermore, the experiment can be con-

ducted with fibers having different refractive indices. If the re-

sults,

or

, are the same for all the fibers, then

they should be the same for vacuum also. Moreover, like the arrangement in a Sagnac-interferometer-
based Fresnel drag fluid flowmeter [8], a fiber loop wound to the conveyor can be broken to leave a gap of vacuum (air), and the light can be taken out of the fiber, guided through the gap, and refocused on the fiber tips, so we can check the time difference in the gap of vacuum (air). Since it is difficult to have gaps for many turns, we will use only one turn of the fiber. We can build a new conveyor with only one turn of the fiber or we also can utilize a FOG and leave un-used fiber still wound to the cylindrical coil. When the conveyor moves, the coil will move translationally. However the translational motion of the coil will not cause any time difference because the translational motion will have the same effect on both counter-propagating light beams. That is why a FOG only detects the rotational motion, and not the translational motion.
To conduct the crucial experiment, we can compare two conveyors that have the same construction except for different

lengths of the gaps: one with a length and the other with

length ,

(Fig. 8). (Because the required conveying

speed is very low, the gap will not move to the arc part of the path). In fact, two FOC’s have the same length of fiber in circular motion, , and the same length of fiber in translational motion. Therefore, comparing the total time differences of the two

March/April 2005

GALILEAN ELECTRODYNAMICS

FOC’s, we can find the time difference in the moving gap with a length of :

Since

,

, and especially,

27

,

,

, we have

Checking whether this time difference satisfies

or

will show whether or

not light speed is constant in vacuum (air). As a matter of fact, if the travel-time difference appearing on the FOC is really not related to the refractive index, then a time difference

would be expected in the experiment.

Since two counter-propagating light beams pass the same gap, small variations of the length of the gap during conveying will not affect this first-order time difference.

ll11

FOOGG

v

dDeetetectcotror

vv vv Ccoouupplelerr

sSoourucrece

vv vv RR

ll22== ll11++ llaa

dDiffiefrfeenret nt lelnegntghtshosfof ggapaspsofof
vvacaucuumum (air)
(or air)

FFOOGG

vv vv vv

vv vv RR

Figure 8. Examining the constancy of the Figure 8.spEexeamdionifngliglihghtti-nspeveadccuounmstan(acyiri)nwvaicthuutmwo(ofriibnearir) with twoofipbteirc-ocpotincvcoenyveeryso.rs.

Examining Light-Speed Constancy in Vacuum (or Air) with Fiber Shearing Parallelograms

Rather than using a FOC, we can more easily conduct an

experiment using the fiber shearing parallelogram arrangement

with a gap of vacuum (air) shown in Fig. 9. There, the top

straight line path, BE, is moving uniformly with speed and the

bottom straight line path, CD, is stationary. Path BE has a gap of

vacuum (air), AF, and paths BC and ED need extra fiber because

the lengths of BC and ED are not constant when moving.

Because CD is stationary, the possible time difference appearing

in BE will not be weakened in CD, so this arrangement is also an

arrangment for conducting the first-order experiment examining

light speed in vacuum (air). We can also compare two

parallelograms differing only in the lengths of gaps of vacuum

(air), and (

), and the lengths of stationary paths.

sSoourucrec dDeteectteocr t

e

or

Ccoouuplperler

vv BBvv

AA l11 FF v

EE

CC Sstatatiotinoanryar y

DD

different
Dlenifgftehsreonf t

lgeanpgs othf s of

gvaacpusumof
(or air)
vacuum

vv

ll222 ==ll11++llaala(air)

BB' vv AA’' ’

FF' vv’

EE' ’

CC'

’

sStataiotniaornyar

DD' ’

FigureF9i.guErxeam9in. inEgxthyaemligihnti-nspgeetdhceonlsitgahncty-sinpevaecduum

(or incaoirn) wstitahntcwyo fiinbervsahceuaruinmg p(aorarllealiorg)rawmist.h

two fiber shearing parallelograms.

Since the motion of the gap of vacuum (air) is the same as the

motion of the gap in a FOC, the same time difference as men-

tioned in FOC’s can be expected here too. Thus, a conclusion can

be made whether or not the principle of the light-speed con-

stancy is correct in paths uniformly moving relative to Earth.

This is a first-order fiber interferometric experiment, and the

Lorentz contraction, a second-order effect, is not a factor in the

experiment.

Highly Precise Experiments

Since the operation of a FOG is based on a first-order effect

and in a FOG two counter-propagating beams share the same

closed path, the FOG is a highly precise measuring instrument.

Since the 1970s, a lot of fiber technologies have been utilized in

the FOG, e.g., broadband light source, single-mode polarization

maintaining optical fiber, bias modulation ensuring operation of

the FOG in the regime most sensitive to input rate, and other

technologies to reduces the noises, making the FOG very sensi-

tive to rotation. Many FOG’s have a sensitivity for the phase

shift of 10-7 rad, where phase shift

and is

the free space wavelength of light.

In a FOC or a shearing parallelogram, two counter-

propagating beams also share the same closed path, and all the

technologies utilized in the FOC and the shearing parallelogram

could be the same as those used in the FOG. It is expected that a

FOC and a shearing parallelogram are very sensitive to motion.

Even if the sensitivity of a FOC and a shearing parallelogram is 2

28

Wang: Fiber-Interferometric Experiments

orders of magnitude less than that of a FOG, a sensitivity of the

phase shift of 10-5 rad can be expected. For a FOC experiment

with the two FOC’s without the gap, if

180 m, = 0.8

vv

µm, and the conveying speed

mm/s, then we could expect

the possible difference of two phase shifts

Vol. 16, No. 2
The MichelsonMMiocrhleelyson-Morley eexxppeerriimmeennt t ((ffrroommFfiigg.. 22bb))

(This difference is much bigger than the phase shift caused by the

Earth rotation because

, the speed caused by the rotation of

Earth, is much slower than 1 mm/s.)

For the experiments with two FOC’s or two parallelograms

having vacuum (air) gaps, if 1.8 m, = 0.8 µm, and the

moving speed

mm/s, then we will have the possible phase

shift in the gaps with length

Thus, even with a fairly slow speed of 1 mm/s, the expected sensitivities of the arrangements are good enough to decide whether or not light speed is constant in moving paths of vacuum (air) and of the fiber. These experiments definitely are highly precise experiments to examine the principle of the light-speed constancy.
Some Interesting Arrangements of FOC’s
Let us examine some interesting arrangements of the FOC. A conveyor consists of rotational motions and translational motions and can have a lot of arrangements. In the first arrangement (Fig. 10a), two paths in translational motion are much longer than the paths in circular motion and the distance between these two translational paths is very small. Omitting the short paths in circular motion, a light beam ‘reflects’ back and forth along uniformly moving paths in the loop, like a light beam in the Michelson-Morley experiment. However, a big difference between this arrangement and the Michelson interferometer is that two counter-moving paths, one for light beam going and one for light beam returning, are provided in this arrangement, instead of only one in the Michelson interferometer. Once again this clearly shows why a FOC experiment is a first-order experiment and the Michelson-Morley experiment is a second-order experiment. With the second arrangement (Fig. 10b), we could examine if it is true that a finite travel-time difference contribution,
, appears in the arc in circular motion regardless the radius of the arc, and if the contribution would suddenly disappear or jump to zero as required by the light-speed constancy when the arc in circular motion becomes a straight line in translational motion.
Another interesting arrangement is a ‘figure 8’ suggested by Whitney [9]. There, the effective enclosed area of the light path is zero. Therefore, any time difference appearing in the arrangement is not related to the classic Sagnac effect, which is proportional to the enclosed area of the light path, and the arrangement does not respond to Earth rotation.

vv vv

S…S

Ccoouupplleerr

vv

detector Detector

sSoouurcrece 1(a0)a.

∆∆tt(N(N∆l∆)l=) =22vv∆l∆Nl/Nc2/c2

∆t ∆(Nt(N∆∆l)l)==0?0?

vv

vv

(1b0)b.
Figure 10. Two interesting arrangements of Figurteh1e0.fiTbwerooipntteicrecsotinnvgeayrrearn. gements of the
fiber-optic conveyor.
Conclusion
Fiber-interferometric experiments, especially experiments involving a vacuum (or air) gap, are crucial first-order experiments to examine the principle of light-speed constancy. Lorentz contraction, a second-order effect, is not a factor in these experiments. All the technologies utilized in the experiments could be the same as those used in the FOG; therefore, it is expected that these experiments will be highly precise, and a moving-paths speed of only 1 mm/s is required for examining light-speed constancy. According to the same analysis as that for a FOG, an increase of length of path in translational motion in the arrangement will lead to an increase of the travel-time difference, a result falsifying the principle of the light-speed constancy.
Acknowledgement
The author would like to thank Dean Langley, Dayou Liu and Jonathan Tang for useful discussions.
References
[ 1 ] G. Sagnac, “L’éther lumineux démontré par l’effet du vent relatif d’éther dans un interférometrè en rotation uniforme”, C. R. Acad. Sci. 157, 708-710 (1913).

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GALILEAN ELECTRODYNAMICS

29

[ 2 ] W.K. Burns, Optical Fiber Rotation Sensing (Academic Press, San Diego, 1994).
[ 3 ] J.P. Vigier, “New Non-Zero Photon Mass Interpretation of the Sagnac Effect as Direct Experimental Justification of the Langevin Paradox”, Phys. Lett. A, 234, 75-85 (1997).
[ 4 ] R. Wang, Z. Chen & X. Dong., “Has the Relativity Principle in the Special Theory of Relativity Been Fully Verified by Experiments?” Phys. Lett., 75A, 176-177 (1980).
[ 5 ] R. Wang, “From the Triangle Sagnac Experiment to a Practical Crucial Experiment of the Constancy of the Speed of Light Using Atomic Clocks on Moving Objects”, Europhysics Letters, 43, 611616 (1998).
[ 6 ] H.J. Arditty & H.C. Lefèvre, “Sagnac Effect in Fiber Gyroscopes”, Optical Lett. 6, 401-403 (1981).
[ 7 ] H.L. Fizeau, “Sur les hypothèses relatives à l’éther lumineux, et sur une expérience qui parait démontrer que le mouvement des corps change la vitesse avec laquelle la lumière se propage dans leur intérieur”, C.R. Acad. Sci. 33, 349-354 (1851).
[ 8 ] A. Tselikov & J. Blake, “Sagnac-Interferometer-Based Fresnel Flow Probe”, Applied Optics 37, 6690-6694 (1998).
[ 9 ] C.K. Whitney, private e-mail communication, 7 December 2001.
Post Script
Because GED has a backlog, the manuscript above is published after the FOC experiment was conducted and reported [1]. There was a travel-time difference ∆t = 2v∆l / c2 between two counter-propagating light beams in a fiber segment of length ∆l moving with the source and detector at a speed , whether the segment moved uniformly or circularly. This result is very natural to those who are familiar with the Sagnac effect and have an open mind regarding the principle of the light-speed constancy. If the Sagnac effect always has a finite value while the radius of the circular motion becomes bigger and bigger, then how can it disappear in uniform motion? In fact, if the experiment yielded a zero travel-time difference in a uniformly moving fiber, then my colleagues and I would have found an unprecedented ‘macro quantum jump’ (Fig. 10b above).
The original Sagnac experiment was conducted in air. Recently, we conducted the FOC experiment with an air light-guide [2], and there was just the same non-zero travel-time difference found in the last experiment. This non-zero travel-time difference between two counter-propagating light beams in a uniformly moving vacuum (or air) light-guide would indicate that the speed of light in vacuum is not independent of the motion of the observer.
I consulted with Ron Hatch, because GPS offers a near vacuum Sagnac situation, and hence another good way to examine the light-speed constancy. One hundred years ago, people had to imagine a train 200,000 km long for thought experiments involving the speed of light, now a geo-stationary positioning satellite has an altitude of 35,860 km and it takes a radio signal 0.12 seconds to reach the ground. This 0.12 seconds is long enough for us to examine whether or not “(photons’) speed is exactly the same for any person who cares to measure it, no matter how fast that person is moving relative to the light beam.” (-U.S. News and World Report, Secrets of Genius, 2003) We care to measure it. However, we have a problem: we’re not sure if relativistic

physicists would agree on a way for measuring it. What do they

mean by saying that the light-speed is the same for any moving

observer? Measuring speed is based on measuring the distance

and the elapsed time. When we say the speed of a bullet is not

the same for all moving observers, everybody knows the defini-

tion of the distance and the elapsed time for the bullet. How-

ever, when it comes to measuring the speed of light, would rela-

tivistic physicists tell us the definition of the distance and the

time elapsed by a light beam for any moving observer? Unfortu-

nately, they would not.

In [3], we proposed a crucial experiment to examine both the

principle of the light-speed constancy and the principle of rela-

tivity. Here we would give a reasonable definition of the light-

speed constancy: there is a light source at one place and two sta-

tionary observers A and B at another place and they synchronize

their clocks.

Now a light beam emits from the source at

t
0

,

and

after t0 , B starts to accelerate towards the source and reaches a

constant speed. In this case, two observers not only have the

same light submission time but also the same distance from the

source when the light beam leaves the source. Then A and B

both receive the light beam and they can compare their reception

times. If their reception times are the same, then the speeds of

light are the same because the distances are the same and the

elapsed times are the same. If the reception times are different,

then the speeds of light are different. This definition is very con-

servative and avoids the problem for the relativity of simultane-

ity, because at

t
0

both observers are stationary.

We really cannot

think of any other definition that could be more satisfactory to

relativistic physicists.

It is interesting to note that this definition can be tested by a

GPS experiment. Locate two GPS receivers, A and B, underneath

a geostationary positioning satellite, at the same place and at the

same altitude on the ground. When a signal is emitted at t , the
0

two receivers are stationary.

After

t
0

,

the

receiver

B

accelerates

upwards at a constant rate, moves 0.7 m and reaches 20 m/s (a

speed of a slow car) in 0.07 seconds, then moves 1 m uniformly

in 0.05 seconds.

About 0.12 seconds after

t
0

,

both

observers

re-

ceive the signal and they compare the reception times with each

other.

To be honest, every person who is familiar with the GPS

could immediately tell that the receiver B would receive the sig-

nal earlier than receiver A would, and the lead is about 6 ns

(1.7m/c). Therefore, our relativistic physicist friends would

probably not accept this as a good definition of the light-speed

constancy. Here, we challenge the relativistic physicists: please

don’t try to make the light-speed constancy un-definable. If you

care to define that the speed of light is the same for any moving

observer, we will design a GPS experiment to show it is not the

truth. Give us a clear definition, and we will disprove it.

References

[ 1 ] R. Wang, Y. Zheng, A. Yao, D. Langley, ”Modified Sagnac Experiment for Measuring Travel-Time Difference between CounterPropagating Light Beams in a Uniformly Moving Fiber”, Physics Letters A, 312, 7-10 (2003).

30

Wang: Fiber-Interferometric Experiments

Vol. 16, No. 2

[ 2 ] R. Wang, Y. Zheng, A. Yao, “Generalized Sagnac Effect”, Phys.

Rev. Lett. 93, 143901-1-143901-3 (1 Oct. 2004)

[ 3 ] R. Wang & R. Hatch, “Conducting a Crucial Experiment of the

Constancy of the Speed of Light Using GPS – Comments on

Ashby’s ‘Relativity and the Global Positioning System’”, Proc. ION

58th Annual Meeting, 495-505, June 2002, Albuquerque, NM.

Comments:

Ruyong Wang

…Ruyong Wang and his colleagues [have] performed a beau-

tiful experiment, which shows that the Sagnac effect occurs with

linear motion as well as circular. This confirms Herbert Ives 1938

suggested experiment to show the same. Actually, the GPS

navigation had already confirmed this—but, as I have letters to

show, the relativists were sticking their head in the sand regard-

ing this GPS evidence.

…The (one-way) Sagnac effect caused by motion of the GPS

receiver relative to the center of the Earth during the signal tran-

sit time from the GPS satellite to the receiver has to be accounted

for to get the correct position solution. Interestingly, the relativ-

ists acknowledge that both 1) motion caused by the rotation of

the Earth, and 2) additional motion of the receiver, had to be

accounted for—but only labeled the former as the Sagnac effect—

I do not know what they used to justify the adjustment for the

latter, but it is spelled out in the latest ICD (Interface Control

Document) that it be accounted for. The magnitude of the effect

from Earth rotation ranges from about plus 30 meters to minus

30 meters in the computed range from the satellites to a receiver

located on Earth’s equator.

Ron Hatch

As someone else who has looked into GPS in-depth and ana-

lyzed it for relativistic information, I would like to add my con-

currence and support for Ron Hatches comments

If we could all get together on the basic experimental facts,

even if not the best physics to interpret them, the dissidents

could have a significant impact on the physics community. At

present, our impact is barely perceptible because we are not all

going in the same direction.

Tom Van

Flandern

Richard Hazelett’s Work

The Einstein Myth and the Ives Papers [ 1 ] is a Festscrift to Herbert Ives, a prolific American scientist and engineer who until his death remained un-persuaded of Einstein theory. Dean Turner and Richard Hazelett compiled the tome in 1979, and included many of the important papers that challenge relativity theory.
When one writes a paper that refers, say, to the MichelsonGale experiment or to the Sagnac experiment, one normally gives the reference. The reader has the option of looking up those papers; however, the journals are not widely available. Consequently, the reader must be strongly motivated to seek out the original work. (That readers do not usually seek out the original work can be easily gauged by the widely-known Haefele-Keating experiment. It is almost axiomatic that your neighborhood physicist hasn’t read it and does not know that the westbound clocks sped up compared to the laboratory clocks.)
Therein lies the value of the Hazelett/Turner book. They gathered not only Ives’s very cogent papers, but also an excellent

collection of papers by Sherwin, Dingle, Sagnac (translated to English), Lovejoy, Michelson, Richtmyer, and others. There are frequent annotations by both Turner and Hazelett. The reader can then read the original work and decide for himself.
I was only very casually acquainted with Dick Hazelett, and know him mainly through the book. I would suggest that the very best way to pay tribute to the man is to read his work.
Reference
[ 1 ] D. Turner and R. Hazelett, The Einstein Myth and the Ives Papers, (The Devin-Adair Company, Old Greenwich, CT. 1979).
Howard Hayden, GED Associate Editor 785 South McCoy Drive, Pueblo West, CO 81007
Updating Faraday (continued from p. 22)
Despite well known Panofsky and Feynman' s statements [4], [12, 13], relativity works at all in electrodynamic phenomena. The absolutely relativistic behavior of unipolar engines puts the end point to recent naive attempts concerning the hypothetical extraction of free energy of space through homopolar machines, as easily can be verified by visiting the Internet.
Moreover, Jehle' s model of the electron [3, 10] must be thoroughly reconsidered on the light of the recent discovery.
Referring to the quoted experiments, Fritz Rohrlich said [14]: ”Your experiments should remove the last shadow of doubt even in the most skeptical minds, that the electromagnetic phenomena are of a relativistic nature.”
References
[ 1 ] H. Poincaré, La Science et L' Hypothesis (Flammarion, Paris, 1868). [ 2 ] A. Einstein, “On the Electrodynamics of the Moving Bodies”, An-
nalen der Physik, 17 (1905); English translation in The Principle of Relativity (Dover, New York, 1952). [ 3 ] D.F. Bartlett et al, “Spinning Magnets and Jehle’s Model of the Electron”, Physical Review D 16 3459 (1977). [ 4 ] W.K.H. Panofsky and M. Phillips, Classical Electricity and Magnetism (Addisson-Wesley, Reading, MA, 1955). [ 5 ] A.K.T. Assis and D.S. Thober, Frontiers of Fundamental Physics (Plenum Press, New York, 1994). [ 6 ] A.K.T. Assis, Weber’s Electrodynamics (Kluwer, Dordrecht, 1994). [ 7 ] J. Guala Valverde and P. Mazzoni, “The Unipolar Dynamotor. A True Relational Engine”, Apeiron 8 41 (2001). [ 8 ] J. Guala-Valverde and P. Mazzoni, “The Unipolar Motor”, Spacetime and Substance Journal 3 (8) 144 (2001). [ 9 ] J.Guala-Valverde et al, “The Homopolar Motor. A True Relativistic Engine”, American Journal of Physics 70 (10) 1062 (2002). [10] J. Guala-Valverde, “Spinning Magnets and Relativity. Jehle vs. Bartlett”, Physica Scripta, The Royal Swedish Academy of Sciences, 66, 252 (2002). [11] J. Guala-Valverde, “Why Homopolar Devices Cannot be Additive”, Spacetime & Substance Journal 3 (14) 186 (2002). [12] W.K.H. Panofsky, Private communication (letter to J. GualaValverde, dated Jan 30, 1995). [13] R. Feynman, The Feynman Lectures on Physics, II (AddissonWesley, Reading, MA, 1964).

Month/Month year

GALILEAN ELECTRODYNAMICS

31

[14] F. Rohrlich, Private communication (letter to J. Guala-Valverde, dated Oct. 2002).
Jorge Guala-Valverde1 & Cristina N. Gagliardo2 1Subsecretaría de Energía- MHOySP, Neuquen Government 2Fundacion Julio Palacios, e-mail:fundacionjuliopalacios@usa.net