DaleSpam, I was discussing absolute time in cosmology. You hold the postion that it cannot exist because of ST's relative time perspective. You introduced Special Theory to combat my hypothesis. Now you are saying I can't use cosmology to support my position. I tend to look for explanation of observed events. You look for 'predictions' and discount the fact those predictions do not match observation and measurement. Dale, I could care less about mathematics. They tend to bore me. Why should I learn the mathematics of a theory whose predictions do not match observation?
Absolutely not. Angular momentum is conserved, it is just not frame invariant. Those are two completely distinct statements. -Dale
Rotational velocities of galaxies and pulsars do not change due to relative motion, distant galaxies do not contract in our line-of-sight vector due to relative motion, conservation of angular momentum is not a law that changes properties due to relative motion, etc. These things have been supported by observation and measurement. Now you ask me to use Special Theory mathematics to prove that something doesn't happen.
Of course. Now, suppose someone is twirling a ball on a string at a speed sufficient to keep the ball on a horozontal plane. You accelerate away from that person until the relative velocity is near 'c', then stop accelerating. Does the rotational speed of the ball slow from your inertial frame? Is the plane of rotation still horozontal wrt the person's hand?
Of course, but you said you weren't interested in astronomy and cosmology, even though General Relativity is a cosmological theory. You could just look at the pictures taken by Hubble and other telescopes to see how the 'contraction' really appears. Please Register or Log in to view the hidden image!
Yes, the rotational speed of the ball slows: Suppose that next to the person is a machine that is twirling an identical ball at the same rate. Suppose further that the machine is controled by a light clock. Now, the rotation of the two balls is at the same rate, but one is coupled to a light clock. As your relative velocity increases the light clock slows so the rotation of the coupled ball must slow. If the laws of physics are the same in all frames then the person's ball must also slow. The first postulate requires that if light clocks slow so do all other kinds of clocks, including gyroscope-based clocks. Otherwise the laws of physics would not be the same in all frames. According to SR your pulsars do not measure absolute time but instead measure proper time like any other clock. -Dale
DaleSpam, Yes, according to ST, the pulsar clock should change tick rates as an observer changes his relative velocity wrt the pulsar. Now, is it the 'light clock' of the 'moving' observer that changes beats, or is it the mechanical clock of the pulsar that 'really' changes? Same with galaxies, if you change the rotational speed of a galaxy, then you have to also change the physical properties of the galaxy, such as the mass. Most galaxies 'appear' to be rotating too fast, not too slow. Galaxies nearby with almost no relative velocity wrt us rotate too fast, distant galaxies that are receeding from us at extreme velocities rotate too fast. By the way, it is common to say 'rotate too fast', but this is an oversimplification. Orbital motion is supposed to be determined by the inverse square law of gravity, which works very well in our solar system. Planets nearer the Sun, such as Mercury, have much faster orbital periods than planets farther away, such as Pluto. Newtonian gravity and General Relativity both the predict the motions very well. What astronomers measure in galaxies, however, is different. They rotate more like your 'rigid disc'. Think of the spiral arms seen in many galaxies. They keep their shape over time, rotating in unison with the galaxy, like a series of geostationary satellites located at different altitudes above the Earth. It does not seen possible from what we know about gravity in our solar system, yet it happens. That is why the 'Dark matter' haloes encircling galaxies were theorized, trying to explain the measured and observed behaviour of galaxies.
I thought I might mention another thing concerning time interval. I had read quite a while back of a proposal to compare different types of clocks in space. No, not the flawed Hefle-Keating fiasco. A simple one was to send them to the International Space Station for an extended period of time, and another was a mission to send them farther out into space on a mission. They were to have both cesium and rubidium atomic clocks that were based on electromagnetic processes, and a quartz crystal oscillator that was based on mechanical processes, the motion of mass. Science has only recently been able to make a very accurate mechanical clock that rivaled the atomic clocks. The purpose, of course, was to determine if it is 'time' that changes, or just changes in electromagnetic processes. I haven't read of any results, but I wouldn't expect any results to be published anytime soon if they contradicted relativity. This is related to my mechanical pulsar clock vs. a bouncing photon clock. I don't expect them to keep time intervals (duration) in a synchronous manner. But the GPS system itself supports an absolute time interval with synchronized clocks, rather than Special Theories prediction that a system of relatively moving clocks cannot be synchronized.
Why should one or the other "really" change? What does that even mean? What would be different if one "really" changed as opposed to the other? -Dale
Why not? It would be Nobel-prize material. Conspiracy theories Please Register or Log in to view the hidden image! -Dale
Anyone who does not have a strong personal opinion about what "real" means is truly a halucination groupie. I wish certain people would stop insinuating that there are conspiracies against those who suspect conspiracies. On an even more serious note, anyone who says that he is unaware that there is a very strong bias against any anti-Relativity message in the academic and professional scientist community is unbelievably naive. U N B E L I E V A B L Y .
I think you're interpreting this in a wrong way. The GPS satellite clocks are synchronized only in the Earth frame, and even then, they are synchronized in the sense that "ticks" on the Earth clock and GPS clocks are simultaneous, which is done by factoring out the relativistic effects on the GPS clocks. All in perfect harmony with relativity theory.
Hi CANGAS, All caps and spaced out, that must mean that you are very very right. I think that kind of comment is silly because it shows a basic lack of understanding about the role of peer-review in science. If anything, I think that the 20th century scientific literature demonstrates the clear willingness of the scientific community to honestly consider ideas and evidence that fly in the face of mainstream theories. The conspiracy-theorists are clearly ignoring the historical record of the scientific community. Anyone who has done any science knows through personal experience the difficulties and the benefits of the peer review process. The difference between scientists and crackpots going through the peer review process is that crackpots blame the reviewers for pointing out the flaws and scientists fix the flaws that the reviewers pointed out. If you want your work to be published in a scientific journal then the work must be science. As my recent conversation with MacM clearly demonstrates, the anti-relativity crowd is full of people that don't grasp the basics of the scientific method. It is hardly a conspiracy when a scientific journal rejects an unscientific paper regardless of the conclusions. I wouldn't expect Time or Newsweek to publish a scientific manuscript so why should a scientific journal publish an opinion piece? -Dale
This sounds like a good experiment. And if you are right then this would be a clear indication that the first postulate is wrong. The frame where the two clocks worked as they are supposed to (according to the textbook laws) would be the prefered frame and would be the only one where physics could really be analyzed. If you are wrong, however, it would be pretty clear evidence that your pulsar clock keeps proper time just like every other clock, as predicted by SR. Nature will be the final judge on the matter. -Dale
2inquisitive, Could you clarify, is this what you meant by "linear Sagnac effect"? The 10s v 2.5s different travel times in the forward and backward directions. -Dale
Dale, I am not sure I understand your diagram. The effect I am speaking of arises on when the receiver is moving, not the emitter. Think of it this way. Place yourself at the emitter's location (frame). Let the emitter send a photon toward a receiver that is moving away from you at speed. It is obvious the receiver will move while the photon races to catch it. Keep the experiment identical as before, except imagine you are in the receiver's location (its rest frame). If you are imagining yourself stationary and the emitter moving away from your position, the photon itself does not appear to have the additional distance to travel once it leaves the emitter. Remember, the emitter of the photon is still stationary as before, you are just assuming it to be moving from your 'rest frame'.
Fabri-Perot interferomenter is "straight line" if I understand what you mean by that. I used one in my Ph.D. research, but was no longer sure of the spelling, so I Googled, as spelling check and happened to note: http://www.kinetics.nsc.ru/center/public/preprint.htm which I did not read but quickly scanned down and saw figure 3 - something to do with a rotating Fabri-Perot! (Also I have not read your post much but you seemed to be concerned with rotating interferometers.) Just looking at their fig 3, I think they rotated to scan a narrow frequency range - I also scanned narrow wavelength range, but had my FP in a sealed nitrogen filled box (with windows of course). By varing* the N2 pressure, I varied the OPTICAL separation between the two silvered plates of the FP. Note I did not put word silvered in quotes as contary to normal, my 200th wave FP was silvered, not aluminium film coated as silver is more reflective if keep in non-oxygen, sulfur-free, atmosphere as mine was. PS - I think my presure scan method is supperior to theirs, as it must be hard to keep plates of FP exactly parallel if it is not stationary. Neither method produces a linear scan rate. I had a large "free spectral range," FSR, - Only about 1mm between the plates so to scan the FSR, an easilly measured pressure difference was required. --------------------------------------------------- *I started scan at a couple of atmospheres and used a small leak to achieve a very steady, but non linear, scan rate. - A large high-precision (mirror behind needle type) pressure guage was calibrated to indicate the central pass wave length.
