Real-Time Physics

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, I also see you always try to give honest answers notwithstanding your bias for your interesting pet theory of matter-time-action and 'collapsing universe'.

In framing my 'simple' question I deliberately avoided the use of frequency and Doppler shift because this has been appropriated and re-interpreted differently from what Christian Doppler meant.

So in your honest reply stating that, "yes, the next pulse comes sooner after we begin our motion (if moving towards source)..."(and later if moving away), you may not have realized that your reply contravenes Lorentz invariance and supports Galilean relativity. 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. This is what the "NULL" in the Michelson-Morley experiment means. NO CHANGE in arrival times due to motion while signal is already in transit.

It is therefore understandable why such a counter-intuitive result has led to much controversy. What was expected was what you said in your honest reply, but that was not what was found. That is what gave birth to SR and Lorentz invariance. That was also what led to the abandonment of Galilean relativity, which your reply supports.

However, there is a special case in Galilean relativity, where motion also has no effect on arrival times despite the presence of motion towards or away from a signal. Here you may recall or browse Galileo's ship thought experiment. As a tip, sound signals moving towards you in the direction that you are moving with the earth's orbital or rotational motion are similarly not hastened or 'come sooner' (in your language) despite your earthly motion towards the source.

I think I have made my case, why IMHO Lorentz invariance should be reviewed.

Regards,

Akinbo

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

A seemingly compelling argument for SR is the measured increase of electromagnetic mass with velocity of an accelerated particle. Lorentz and before him FitzGerald imagined length contraction and arrived at the Lorentz factor.

The similarity with resonance and the relation epsilon_0 x my_0 = 1/c^2 led me to the suspicion that electromagnetic mass might not belong e.g. to neutrons. Is someone aware of a calculation of the electromagnetic mass via the law of Biot-Savart? I imagine the magnetic field H of a moving charge looking like a donut. The vector product with its electric field E should yield the force that is directed against the motion.

If I am correct in that then perhaps we need neither Pentcho's denial of c nor Barbour/Smolin's twist.

Eckard

Quote"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."Lee Smolin quoted by Pentcho Valev

What one is to make of it Professor, is that the non simultaneity of events is due to the distribution of potential sensory data in the environment. When and where it is received leads to the experienced present, an emergent reality. Different observer locations give different experience of same events (non simultaneity), simultaneously (as foundational reality is uni-temporal). It certainly does not imply that the whole of history past and future too is laid out. Only that which has occurred in foundational reality has provided the sensory data by which it might be known. The potential sensory data in question is only EM data by which images can be fabricated not material (made of atoms)objects and events. This realization overcomes the Grandfather paradox and makes Barn pole and Andromeda paradoxes intuitive. They relate to data and output images processed from it not actual objects or happening events.

The image of an object far away looks smaller than the image of the same object close by. It also takes longer for the light to be reflected from an object far away than close by. So the Image of the smaller object is from older data than for the larger nearer object. So size of image can be used as proxy for age of data. Though size of source Object rather than image can also vary. This reminds me of an episode of Father Ted. (Explaining to Dougal) "One last time" (Holding two toy plastic cows) "These are small but the ones out there" (gesturing to the window) "are far away, (Pause) Small- far away, Oh forget it. .

Talking about trading places, instead of taking us on another futile journey into the world of shape dynamics by trading the relativity of time (seconds) for relativity of spacial scale (metres), how about trading relativity of velocity (metres/ second) instead. Buy one get two free!

Akinbo

Einstein Demolished Science - Now a Second Demolishing?

"Einstein and others demolished the view that space and time are an unchanging background to physical events. (...) The time has come for a second demolishing."

How did Einstein demolish space and time? By introducing his false constant-speed-of-light postulate of course:

"And by making the clock's tick relative - what happens simultaneously for one observer might seem sequential to another - Einstein's theory of special relativity not only destroyed any notion of absolute time but made time equivalent to a dimension in space: the future is already out there waiting for us; we just can't see it until we get there. This view is a logical and metaphysical dead end, says Smolin."

Roberto Mangabeira Unger and Lee Smolin, don't demolish science further (there is not much left of it). Just denounce Einstein's 1905 false constant-speed-of-light postulate.

Pentcho Valev

"Just denounce Einstein's i905 constant-speed of light postulate."

Fortunately, Adolf Hitler did just that. But then he did not understand that it was not Einstein that demonstrated that constancy conclusively, it was James Clerk Maxwell. And if you wish to denounce the postulate to denounce the man, you must then offer a consistent and complete explanation of how it could possibly be that chemical reactions always occur in identical combinations at differing velocities as has been consistently shown in corresponding experiments on earth and on the space station.

"...the study of mathematics starts with the teaching of arithmetic, a horrible, wretched subject, far removed from real mathematics, but perceived to be useful. As a result vast numbers of intelligent people become 'mathematic avoiders' even though they have never met mathematics." Peter Hilton: Distinguished Professor of Mathematics, Emeritus State University of New York at Birmingham

adapted from "The Mathematical Component of a Good Education" Miscellanea Mathematica, Springer-Verlag, Berlin, 1991 from the forward, page xviii of "Mathematics, From the Birth of Numbers" by Jan Gullberg - 1997 - W.W. Norton & Company - ISBN 0-393-04002-X