Real-Time Physics

Even better way is make each interferometer arm also in geosynchronous orbits at the horizons along rotation and perpendicular to rotation. This makes each arm 35,200 km given 35,800 km geo orbit and 6,400 km earth radius.

Each interferometer arm pulse will be slightly less than the main pulse, 0.117 instead of 0.119 s and the moving frame will measure the arm in the direction of motion to have an 8.8 ps delay due to the 2.6 km/s relative velocity between arms. The rest frame will not measure any pulse difference between arms.

Of course, there will be some extra delays due to atmospheric refraction and noise due to atmospheric variability will mean some period of signal averaging. But these are the same rest and moving frame calculations that the GPS satellites do many times per second along with clock delays due to gravity. Every time you use a GPS device you implicitly validate MEE and Lorentz invariance.

Anon, et al,

May I offer a glass of beer? It clarifies thinking.

Observe a light pulse passing through the glass & beer at c/n... (the other 99% of the post seems to be lost in cyberspace due to use of a forbidden symbol!; A concise version;)

Now are you seeing the pulse? No of course not, you're seeing a sequence of emissions from particles charged by the pulse, each emitting light at c.

So if you then drive past the glass in a car at v, does the glass need to shrink to stop propagation speed in the glass exceeding c? Do some of us really believe the glass must contract in length? You are joking ...right? Why?

Ah a vacuum. OK, we'll drink the beer and seal a vacuum into the glass, with just a few particles to 'glow' when hit by the pulse so we can follow the track. Each of those still emits at c.

So we drive past at v again. This time with a fast video camera. The replay shows us apparent c+v, but there's no REAL c+v anywhere!

There are TWO cases of light speed 'Propagation' speed as Einstein's Postulates, and 'relative' or 'closing' speed. Just as there is between your spacecraft and the one coming the other way. Light arriving is instantly scattered' (absorbed and re-emitted) to the local c. How else do we really get Doppler blue shift (wavelength reduction).

Can someone please identify where the light was supposed to be propagating at more than c to cause all the paradoxical nonsense we still have to suffer as 'interpretation' of two perfectly sound postulates.

Or anyone who thinks the above is logically flawed wrong please do explain where and why.

Thanks

Peter

Steve,

On Nov. 21, 2014 @ 04:19 GMT you wrote: "velocity affects that science has measured". Is this correct? I guess you meant effects of v^2. Doppler effect depends on the sign of v.

I am sorry for putting my question in the wrong path.

John C,

I trust in the Encyclopedia Britannica in that Lorentz in 1892 developed the concept of length contraction independent from Fitzgerald's short article in 1889 although the Encyclopedia calls Einstein in 1905 a German/American physicist, speaks of the Michelson-Morley experiment in the 1880s instead of Michelson's 1881 published experiment in Potsdam and his 1887 published with Morley experiment in Cleveland, and even worse it declares space contraction a logical consequence of the relative motion of different observers instead of admitting that Michelson's null results in the 1880s can be interpreted as did Michelson himself: as evidence against the hypothesis of a light-carrying medium without length contraction, Poincaré synchronization, and time dilution.

Eckard

Steve, you seem to have missed out on what the argument of the last 100 years has been all about and innocently cling strongly to Lorentz invariance.

Examples:

"I thought that you had asked a simple question about any rest frame measure of a difference in length of each of two interferometer arms. Since v = 0, the answer is no difference and there is no need to talk about contraction or dilation".; "Then you begin to speak about some kind of length contraction, which means that now there is a moving frame from which separate moving observations occur. I was just trying to fill in the blanks. There is no sense in talking about a stationary interferometer changing length in a rest frame. You need a moving frame and to measure the rest frame interferometer from the moving frame to even talk about contraction".

Michelson, Morley and their interferometer WERE AT REST TO EACH OTHER in 1887. According to Lorentz invariance, since the earth on which they are situated and AT REST is moving, the arm of the interferometer (i.e. the light path) will undergo length contraction and time dilation to EXPLAIN the constant light arrival times. Michelson and Morley WERE NOT measuring the rest frame interferometer from the moving frame, yet Lorentz invariance talks about length contraction!

"Light can and does change speed, just not in a comoving frame"

This is more or less a statement of Galilean relativity (invariance) as opposed to Lorentz invariance.

In Lorentz invariance, whether comoving or from different frames, velocity of light is invariant!! It is therefore amusing that you seem to support what Lorentz invariance holds as untrue, yet claim you are supporting Lorentz invariance.

"But these are the same rest and moving frame calculations that the GPS satellites do many times per second along with clock delays due to gravity. Every time you use a GPS device you implicitly validate MEE and Lorentz invariance"

Again, you mix up issues. Motion of the receptor DOES NOT have any influence on signal arrival times in Lorentz invariance! Michelson and Morley's experiment seemed to show results supporting this using earth's orbital motion. However, in 1913 Sagnac performed his experiment using receptors on turntable and demonstrated that receptor motion CAN AND DOES affect signal arrival times. So what you see in GPS is a Sagnac effect, which if you go back to the history negates Lorentz invariance which was claimed to hold due to the 1887 experiment and the SR theory that followed in 1905. The Sagnac effect was actually buried for years and only when observations in GPS became inevitable, those observations are now being fraudulently appropriated as being in support and a manifestation of GR, not Lorentz invariance which they contradict.

(From your other post) "the moving frame will measure the arm in the direction of motion to have an 8.8 ps delay due to the 2.6 km/s relative velocity between arms"

If you now research further and find that Lorentz invariance preaches that there will be no delay due to the relative velocity between the arms, will you then abandon Lorentz invariance?

Actually, experiments have been done to find out whether earth rotation can affect signal arrival times on earth surface, and the results seem to suggest earth rotation has no such effect. The question and the experimental task is to then find out at what height above earth surface does earth rotation begin to affect signal arrival times as confirmed in the GPS observations.

Regards,

Akinbo

Now let me see if I got this straight. A rest frame interferometer necessarily undergoes some kind of change because of some kind of velocity and MEE simply misinterprets the lack of change and there are actually two different changes that somehow cancel out...

And the Sagnac effect, which is a very well defined and well understood effect of rotation of light, now has something more to do with its translation as well as rotation...

And all of the GPS calcs that claim they are due to gravity and velocity (squared) corrections are all simply just lucky to get the right answer for location on earth...

All with just simple declarative statements of fact that appear to contradict a large body of experimental evidence, all without a single calculation. Normally answers to simple questions that include measurements and calculations help people to better understand and predict action, not obfuscate.

I simply do not know how to respond to declarations of belief that are inconsistent with measurements and calculations. You can of course believe in anything that you want as long as you are not in charge of GPS programming...or satellite navigation or precision clocks. It is not clear what predictions of action you believe are improved by rejecting the very nice system of MEE that works so darn well.

Michelson and Morley and hundreds of later experiments show that the time delays of interferometer arms at rest do not depend the orientation or location of the interferometer. Period. Motion has nothing to do this this result and it is simply an observation of fact.

Now MEE is consistent with this result and that makes a nice story that helps make GPS part of the same story and it seems all very consistent. Accurate GPS calcs include both gravity and v2/c2 time dilation, so there is no mystery there...just look it up.

Now you want to throw MEE under the bus because you can't understand why a moving interferometer is different from a rest interferometer, or why light stops at a black hole, or why light is slowed and bent by gravity.

You can spend a lifetime in these kind of rabbit holes...

When I say velocity effects, I mean all velocity effects, doppler and MEE time dilation.

"On Nov. 21, 2014 @ 04:19 GMT you wrote: "velocity affects that science has measured". Is this correct? I guess you meant effects of v^2. Doppler effect depends on the sign of v."

Most common calculations involve a combination of the two effects after all.

Thanks Steve for the exchange. May I just ask this one last question, and perhaps I may finally be a convert to collapsing universe, MEE and Lorentz invariance.

If you are 3 x 108m away from a source emitting light every one second, assuming c = 3 x 108m/s you receive a signal every one second.

If on receiving the last signal, half a second later to ensure the next incoming signal is already in transit, can you hasten its arrival time to below one second by moving towards source or delay the arrival time above one second by moving away?

I think that wraps things up. Eckard I think I will like your answer too because you sometimes get things mixed up, what 'constant speed of light' means.

Akinbo

Akinbo,

As I explained in an essay of mine, the velocity of something in linear motion from A to B without acceleration results from the distance between the position in space of A at the moment of emission and the position in space of B at the moment of arrival divided by the time of flight. Neither the velocity of emitter nor that of the receiver do directly matter.

You are right, I had to correct a mistake that I shared with Maxwell, Lorentz, and others. In case of waves in a medium like air that moves relative to A and B, already Michelson's first experiment 1881 under the auspice of v. Helmholtz in Potsdam near Berlin would have provided a non-null result.

Einstein preferred for a while Newton's idea that light behaves like a bullet. In this case its velocity would depend on its value given by the emitter. His SR postulates a constant c without obeying the definition I gave above. Instead he adopted the Poincaré synchronization as to achieve formal agreement with gamma which was fabricated by Lorentz as to defend a light-carrying medium.

Steve,

Einstein claimed in 1905 that his SR could be checked experimentally. He wrote: "This relation allows an experimental check because the velocity of the electron can also be directly measured, e.g. by means of rapidly oscillating electric and magnetic fields" [my translation]. Who performed this experiment, and would it likewise be valid for motion toward and away from what Einstein called the frame of rest? Neo-Lorentzians like T. Van Flandern denied this.

Eckard

You are so resilient...I like stubbornness as long as reason is involved. We are after all still figuring out how the universe that we live in works.

"If you are 3 x 108m away from a source emitting light every one second, assuming c = 3 x 108m/s you receive a signal every one second. If on receiving the last signal, half a second later to ensure the next incoming signal is already in transit, can you hasten its arrival time to below one second by moving towards source or delay the arrival time above one second by moving away?"

So we are back to moving and rest frames, but coming toward each other, so we see the pulse frequency increase due to doppler shift. So yes, the next pulse comes sooner after we begin our motion. Or we see the space shrink due to dilation and that is why the pulse frequency increases. But the moving clock is no different than it was before motion according to the moving frame.

You ask simple questions like a lion on the stalk, ready to pounce on and consume a suitably juicy answer...

I don't know who performed this experiment.

"Who performed this experiment, and would it likewise be valid for motion toward and away from what Einstein called the frame of rest?"

However, every accelerator and TV picture tube uses the equivalence for electron deflection between magnetic and electric force.

Steve,

While Einstein didn't write what he meant with magnetic and electric Ablenkbarkeit, we may imagine an electric field causing an upward deflecting force Y on a moving electron while simultaneously a magnetic field causes a downward deflecting force N which compensates Y just for a particular positive velocity v.

According to N = v x B, the sign of N reverses with negative v but the sign of Y doesn't change.

Incidentally, I feel deterred by several details, e.g.: "a ponderable material point can be made an electron (in our sense) by adding an arbitrarily small electric charge".

Eckard

Eckard,

What you said is correct, viz. "...the velocity of something in linear motion from A to B without acceleration results from the distance between the position in space of A at the moment of emission and the position in space of B at the moment of arrival divided by the time of flight. Neither the velocity of emitter nor that of the receiver do directly matter".

As I said in my reply to Steve (who I thank for agreeing to answer my last simple question), this is Galilean relativity in action. Your reply indirectly agrees with the concept of resultant or relative velocity, which is to be understood differently from the value of velocity of propagation. What I mean is that your answer agrees that the position of B that is important for calculating velocity IS position in space of B at the moment of arrival, NOT at the moment of emission., which Lorentz invariance means. In Lorentz invariance even though it is seen that the position of B has changed from what it was at the moment of emission, a mysterious mathematical mechanism comes into play to preserve that position (i.e. the mechanisms of length contraction and time dilation). In summary, you are saying the same thing that Galileo and Newton already told us in their theory of dynamics.

Regards,

Akinbo

Yes Akinbo,

Michelson tried in vain to measure a motion relative to Maxwell's hypothetical medium. Empty space doesn't have a point zero to refer to. It is just distances between locations. You are right, this is no new insight.

The only "fix" point in universe is the permanently moving relative to the agreed Christian timescale point now between past and future. Einstein's Poincaré synchronization was aptly called by Van Flandern a de-synchronization. The now can be shifted at will only on the level of abstract time, not in reality. Georgina seems to have understood this. Einstein, Steve, and Tom perhaps didn't.

Eckard

You have thought all of these conundrums through much better than I have. But the math works fine.

"In Lorentz invariance, moving towards a light signal already in flight CANNOT hasten its arrival time, neither will moving away with the signal chasing after you delay its arrival time."

It is the inevitable ambiguity of language that complexifies complexity. Whenever you mention a problem that you have with MEE, you fail to specify which frame you are in. There is no change in interferometer arms for Michelson and Morley because they are in a rest frame. (There is a rotation effect, the Sagnac effect, but that has to do with the rotation of light, not its translation.)

Why you keep moving one arm or the other in your mind is how your mind works, but that is not how Lorentz invariance works.

Now when you introduce a moving frame, that does not change anything for the rest frame interferometer and Michelson and Morley can only know about the moving frame by looking outside of the rest frame. Once you introduce a moving frame and have that frame in communication with a rest frame, you now have the typical doppler shift effect, but with light pulses instead of continuous light waves.

It is actually easier to use light pulses for these kinds of discussions anyway.

Now in your mind, the moving observer simply by moving towards the source, has managed to get information from the source, a pulse, faster than the speed of light would allow. This is a very reasonable statement and has a basis in intuition, but the math does not work out. If you want to make your case, you must get information from the rest to the moving frame faster than c. Otherwise, everything that you have said is consistent with MEE.

Now in order to explain the limitation of c by MEE, you need to invoke the holy grail of time and space dilation and simultaneity and roll out your Minkowski diagrams and so on. Now the math monster rears its ugly head and many end up nodding off, since our language and common experience simply do not include the effects of MEE.

In fact, the space in between is contracting and so we are not receiving the pulse sooner because of time, but because of spatial contraction. Light pulses keep moving at c, but the space between rest and moving frames is now contracting at ~v2/c2, which we observe as a doppler shift, v/c. Oh, and that darn source clock has slowed down by the same factor.

So now we have a conflagration of spatial dilation, time dilation, and doppler shift and we are trying to describe this with a language and intuition that evolution has simply not provided beyond common predictions of action. Simultaneity down to better than a heartbeat is simply not needed for common experience.

So to avoid the ugly math, go to the geosynchronous orbit example that I gave before. Although there is the complexity of gravity effects, there is no motion doppler involved to complexify things. Synchronizing the moving and rest clocks compensates for gravity effects, but space and time dilation due to velocity, v2/c2, persist and are easy to calculate and communicate. Moreover, that is how our GPS system works and so we do not have to argue about an experiment done 150 years ago. The GPS performs this calculation many time a second for hundreds of millions of observers on the earth's surface.

This is an interesting conflagration of ideas, so I finally broke down and looked up van Flandern and his Lorentz relativity (LR) versus GR's mass-energy equivalence (MEE) and its Lorentz invariance.

"Michelson tried in vain to measure a motion relative to Maxwell's hypothetical medium. Empty space doesn't have a point zero to refer to. It is just distances between locations. You are right, this is no new insight. The only "fix" point in universe is the permanently moving relative to the agreed Christian timescale point now between past and future. Einstein's Poincaré synchronization was aptly called by Van Flandern a de-synchronization. The now can be shifted at will only on the level of abstract time, not in reality. Georgina seems to have understood this. Einstein, Steve, and Tom perhaps didn't."

Fortunately, the rabbit hole was not very deep and in fact, van Flandern has a very good point.

Now GR and LR both use exactly the same math as van Flandern so nicely describes...so it is not surprising that both GR and LR are fully consistent with MEE. The difference between LR and GR is simply that LR assumes an absolute frame, say the CMB, and GR assumes no absolute frame except the walls of the universe and the event horizons of all the black holes.

"Empty space doesn't have a point zero...{except for} the permanently moving relative to the agreed Christian timescale point {as} now between past and future."

It is true that the western (i.e. Christian) calendar begins its year zero near the time of Rome's subjugation of Judea, a significant event that nevertheless is just a convenient zero year and other calendars use other significant events as convenient zero years. The most convenient zero year for science, though, is the CMB at z = 1091. Science knows the CMB very precisely and anyone in the universe who measures the same CMB time as we do we imagine as coresident in the universe.

The further GR description of a universe where gravity action is due to gravitational distortion of space works quite well for a large number of predictions. Gravity distortion of space occurs as a result of the norms of matter and time and so the gravity distortion of space determines a single path or future for each object ahead of action. As a result, the GR universe does not account for the many possible futures of quantum action very well at all.

Although there is agreement between GR and LR about the existence of both rest and moving frames, LR presumes a single absolute rest frame, an aether as it were, through which the rest of the universes moves in its many moving frames. The interesting complement in quantum action to the two time dimensions of rest and moving frames is the trimal notion of a ground state, an excited state, and an excitation that couples the ground and excited states.

Instead of the dual universe of relativity as rest and moving frames, the quantum universe is a trimal of ground state, excited state, and excitation. Now we can simply connect the logic of these two universes by supposing that the rest and moving frames of GR or LR represent the ground and excited states and some excitation by some third object, say a photon, then completes the description of action.

What the principles of GR and LR both lack is that very important third principle of the trimal; the exchange of matter that connects the rest and moving frames. Since macroscopic objects moving in time under gravity depend mostly on the norms of matter and time, GR and LR work quite well up to certain diffeomorphic limits (I love that word diffeomorphic...it sounds so differomorphic). All action in GR follows from gravity distortion of space, not from matter exchange.

Although all force is due to matter exchange, gravity force is mainly due to pairs of exchanges, i.e., neutral matter changes and not charge matter exchanges. Thus matter and time norms describe gravity force very well with spatial distortion without the exchange of amplitudes and phases that is the underlying quantum reality.

Akinbo, Steve,

You stubbornly mentioned Morley although he didn't add something basic to Michelson's wrong expectation and his correct null result. In case of Steve this might indicate unnecessary patriotism because already Abraham Michelson was an American despite of his Polish roots.

Steve,

If only the position B of arrival on the target/observer matters then we need not dealing with any motion of B. The argument of faster than light transfer of information is then not tenable.

Akinbo,

Doppler shift in the sense of what Christian Doppler meant is still reasonable and valuable. It doesn't need His reinterpretation.

It doesn't matter whether or not light is "already in transit". "The NULL in the Michelson ... experiment" is not necessarily counter-intuitive but reasonable if one admits that c does not refer to Maxwell's hypothetical medium.

In other words, empty space doesn't behave as does air.

How to most easily understand the Sagnac effect measured by the late Michelson?

It is obviously due to rotation of a xy plane of rederence. May we ignore the y projection and interpret the light as propagating back and forth in x projection which increases the total distance between A and B?

Eckard

Steve,

Van Flandern clearly rejected Einstein's "de-synchronization". His LR nonetheless adopted the interpretation of length contraction to the propagation of electromagnetic waves by Lorentz himself which seems to be confirmed by overwhelming evidence for the usefulness of the factor 1/(1-v^2/c^2).

The same factor 1/(1-omega^2 L^2 C^2) occurs in case of electric resonance at L and C which are lumped elements that describe wave impedance with Z^2 = L/C.

Electromagnetic waves always propagate forward with increasing time; c is never negative.

Eckard

"L^2 C^2" should of course read "LC" which equals to (1/c)^2.

We must not interpret the accordingly reduced speed of propagation as due to length contraction or time dilution.

Eckard

Can absolute simultaneity be restored without abandoning Einstein's 1905 false constant-speed-of-light postulate? Yes - Einsteinians know no limits. Julian Barbour and Lee Smolin have found it profitable to trade the relativity of time for a relativity of size:

Aspects of Time, Julian Barbour, Warwick, August 24th 2011: "Was Spacetime Glorious Historical Accident? Time will not be fused with space but emerge from the timeless shape dynamics of space. Absolute simultaneity restored!"

Lee Smolin: "What, then, is one to make of the relativity of simultaneity in special and general relativity? Doesn't the experimental success of relativity imply that time's passage is a chimera, so that all that is real is the whole history of the universe laid out at once? That point of view, the block-universe perspective, led Albert Einstein to declare in a letter to the family of his friend Michele Besso that the "distinction between past, present, and future is only a stubbornly persistent illusion." A reformulation of general relativity called shape dynamics resolves the quandary posed in the previous paragraph. The theory trades in the relativity of time for a relativity of size but does not give up any of the experimental successes of special and general relativity."

The Singular Universe and the Reality of Time, Roberto Mangabeira Unger, Harvard Law School, Massachusetts, Lee Smolin, Perimeter Institute for Theoretical Physics, Canada, pp. 386-387: "In general relativity two clocks traveling different paths through spacetime will not stay synchronized. But their sizes will be preserved... (...) But the amazing thing is you can get to general relativity by trading the relativity of time of that theory for a relativity of spacial scale... (...) The resulting theory is called shape dynamics. (...) This means that there is now a physical meaning to the simultaneity of distant events."

Pentcho Valev