Abstracts Details

Based only on the Galilean addition of velocities and the de Broglie relation, it is deduced that in a matter-wave interferometer with slow-speed particles, a moving segment of deltaL with a velocity V contributes deltaPhi = (2Pi/vlamda)VdotdeltaL to the total phase difference of the interferometer, where v is the speed of the particles and lamda is the wavelength.. This expression is exactly the same as the generalized Sagnac effect for light waves found by experiments except that v is replaced by c. For a rotational motion, it leads to the Sagnac effect. Additionally, the scientific value of this relationship is also to explore the possibility of detecting translation speeds by a matter-wave interferometer. Two configurations of the experimental setup have been indicated and the key element is that the paths of the interfering beams constitute a loop with an opening. If the possibility is confirmed by experiments, the conclusions will be that there is a preferred reference frame for matter waves and a speedometer with a very high sensitivity is possible.

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.

*Physical Review Letters.* Experiments were conducted to study light propagation in a light waveguide loop consisting of linearly and circularly moving segments. We found that any segment of the loop contributes to the total phase difference between two counterpropagating light beams in the loop. The contribution is proportional to a product of the moving velocity v and the projection of the segment length ??l on the moving direction, ??ϕ=4??v????l/c??. It is independent of the type of motion and the refractive index of waveguides. The finding includes the Sagnac effect of rotation as a special case and suggests a new fiber optic sensor for measuring linear motion with nanoscale sensitivity.

*Physics Letters A.* A fiber optic conveyor has been developed for investigating the travel-time difference between two counter-propagating light beams in uniformly moving fiber. Our finding is that there is a travel-time difference ??t=2v??l/c^{2} in a fiber segment of length ??l moving with the source and detector at a speed v, whether the segment is moving uniformly or circularly.

With a Michelson interferometer using a phase-conjugate mirror (PCM) that reverses the uniform phase shift in a light path, we can conduct a first-order experiment of Special Relativity. Utilization of the PCM changes the basic concepts of an interference experiment. Placing a conventional partially reflecting mirror just in front of the PCM at the end of a light path, we can test the isotropy of the one-way speed of light in a system moving uniformly in a straight line and conduct the one-way Sagnac experiment. According to the reported phase-conjugate Sagnac experiment using a segment light path, we can expect that the phase shift is phi = 4pivL/clambda in the one-way Sagnac experiment with path length L and speed v, even with an increasingly larger radius of the rotation. Based on these and the experimental fact of the generalized Sagnac effect, it is very important to examine whether there is the same phase shift for the test of the one-way speed of light and the first-order experiment using the PCM in a system in straight-line uniform motion. The sensitivities of these experiments are very high.

*Proceedings of the ION 58th Annual Meeting & CIGTF 21st Guidance Test Symposium*, 24-26 June 2002, pp 495-505. Contrary to the assertion of Special Relativity, the speed of light is not always constant relative to a moving observer. The Global Positioning System (GPS) shows that the speed of light in the Earth Centered Inertial (ECI) non-rotating frame remains at c relative to the frame?but not relative to an observer or receiver moving in that frame. When a GPS receiver changes its translation speed relative to the ECI frame, the speed of light measured relative to the receiver changes. A crucial experiment of the constancy of the speed of light relative to a moving receiver could be conducted in the following way: Let two GPS satellites and two airplanes be positioned in a straight line. Let the two airplanes travel at the same speed directly toward one of the two satellites and directly away from the other satellite. The travel time differences of GPS signals arriving at the two airplanes is measured and recorded with the airplanes flying first toward one of the satellites and then flying the opposite direction toward the other satellite. The travel time differences obtained as the airplanes fly in opposite directions are compared. If the travel time difference is the same when the velocity of the airplanes is changed, then the speed of light is indeed constant relative to the moving airplanes, otherwise it is not. The calculation using the GPS range equation and the results of a Real-Time Kinematic (RTK) differential GPS test have shown that the constancy of the speed of light relative to moving airplanes is not correct. The change of the time difference could reach about 10 ns for subsonic airplanes and 30 ns for supersonic airplanes. The result of this crucial experiment is not only important scientifically, but also indicates the possibility of a new way to directly measure vehicle speed relative to the ECI frame.

Proceedings of the IAIN World Congress in association with the U.S. ION Annual Meeting, 26-28 June 2000, 90.

Proceedings of IEEE 2000 Position Location and Navigation Symposium (IEEE Catalog Number: 00CH37062), March 13-16, 2000, 162

*Europhysics Letters 43 (1998) 611.* According to the triangle Sagnac experiment, between point A and point B that are moving in a circular motion, the travel times for light or radio signals from A to B and from B to A are different. The difference ?t, i.e. the Sagnac effect, equals 2V_{D}L/c^{2}, where D is the foot of the altitude to AB, V_{D} is the speed of point D and L is the distance from A to B. The Sagnac effect exists whether the radius of the circle is as small as only few centimeters, e.g., in fiber-optic gyroscopes, or as big as twenty thousand kilometers, e.g., in GPS. Therefore, if we mount an atomic clock and signal transmitter and receiver on each of two objects moving at the same speed in a circular motion (it is not necessary to synchronize the two clocks beforehand), we will find such a time difference. Practically, using sufficiently large L and V_{D}, this time difference can reach around 1 ns, which is relatively easy to detect with current technology. This experiment would yield both practical applications and theoretical implications. First, it can be used as a verification of Sagnac corrections in GPS. Second, a theoretical problem arises when these two objects change their paths to a straight line. Would the time difference still exist (then it contradicts the principle of the constancy of the speed of light) or does the time difference "jump" to zero? The result of the experiment will be of great interest.

*Physics Letters 57A (1980) 176.* Up to now all experiments used to verify the special theory of relativity have been done with the earth as the reference system. A suggested new Michelson-Morley experiment in Space Lab will be the first to examine the relativity principle in an inertial system other than the earth.