Do AEST (Absolute Euclidean Spacetime) models work?

[name123]

TL;DR Summary

Asking whether AEST (Absolute Euclidean Spacetime) models work, in the sense of giving the correct predictions?

I was reading a paper by J.M.C Montanus which was published in <low quality journal reference removed> in which he claims under AEST the new gravitational dynamics and electrodynamics are reformulated in close correspondence with classical physics, and subsequently leads to the correct predictions for the deflection of light and the precession of perihelia while being based on a flat spacetime. My question is, does the AEST approach work, while preserving proper time momentum, and flat Euclidean spacetime (even with gravity), or are there problems with it?

[As a side issue, the idea behind AEST seems linked to the ideas in Lewis Carroll Epstein's "myth" (apparently published in the book "Relativity Visualized" in 1981) in which everything moves at the speed of light. I have attached a picture from David Eckstein's explanation of the book, showing how the time dilation, length contraction, and relativity of simultaneousness.]

 

[name123]

Didn't see file attached, so re-attaching

 

[Dale]

The Hadronic Journal is not very reputable certainly. It doesn’t even have an entry in the Clarivate Master Journal List, nor is it found at Eigenfactor. So for a “groundbreaking” paper to be found in such a journal is a bad sign.

On a technical perspective, the problem with space-propertime is defining what a point is in that concept. A point in spacetime is something that happens at the same place and time. So a collision is two objects whose worldlines intersect, at that point they are at the same place at they same time and they therefore collide at the intersection. With space-propertime there is no physical meaning of the points. Objects with intersecting worldlines don’t collide and objects that do collide don’t necessarily have intersecting worldlines.

The community doesn’t find such a notion useful, so it is banished to such journals.

 

[martinbn]

What exactly is the paper?

 

[Dale]

It doesn’t matter, the journal doesn’t meet our standards so we won’t link to it here

 

[Vanadium 50]

The Hadronic Journal is not very reputable

The street address is some guy's apartment. Not a good sign.

 

[name123]

The Hadronic Journal is not very reputable certainly. It doesn’t even have an entry in the Clarivate Master Journal List, nor is it found at Eigenfactor. So for a “groundbreaking” paper to be found in such a journal is a bad sign.

On a technical perspective, the problem with space-propertime is defining what a point is in that concept. A point in spacetime is something that happens at the same place and time. So a collision is two objects whose worldlines intersect, at that point they are at the same place at they same time and they therefore collide at the intersection. With space-propertime there is no physical meaning of the points. Objects with intersecting worldlines don’t collide and objects that do collide don’t necessarily have intersecting worldlines.

The community doesn’t find such a notion useful, so it is banished to such journals.

He also has a paper in the Foundations of Physics Journal which seems to me to be in the Clarivate Master Journal List
Proper-Time Formulation of Relativistic Dynamics (Found. Phys. 31, Issue 9, Sep 2001, Pages 1357 - 1400)

There was also <another bad reference>

Also not sure what you mean by space-propertime having no physical meaning. In the Epstein explanation I mentioned by David Eckstein (David Eckstein Relativity search should find it), in the Epstein section (4.2 or C2) it seems to have an example where "A and B met at O and at that point both set their clocks to zero", and it shows how to use the diagram to predict time dilation, length contraction etc. It also seems to go onto indicate what is meant by propertime in C3 'Clocks that got synchronized at the meeting in O will any time later be located on a half circle centered in O. I would suggest the name synchrone for such a half circle. Both events, "Black reaching the space-time-position A" and "Red reaching the space-time-position B" are simultaneous for Black and Red, however both are telling us that the reading of the other's clock lies behind'

​

 

[martinbn]

He also has a paper in the Foundations of Physics Journal which seems to me to be in the Clarivate Master Journal List
Proper-Time Formulation of Relativistic Dynamics (Found. Phys. 31, Issue 9, Sep 2001, Pages 1357 - 1400)

https://link.springer.com/content/pdf/10.1023/A:1012274211780.pdf

<bad reference removed>

Why are you interested in this? You would spend your time better if you studied relativity.

 

[name123]

https://link.springer.com/content/pdf/10.1023/A:1012274211780.pdf

<bad reference removed>

Why are you interested in this? You would spend your time better if you studied relativity.

Thanks for the link.
Personally I am interested more from a philosophical point of view. As I understand it, in the early 20th century it was thought by those such as the Vienna Circle that science had shown Kant's a priori idea of Euclidean geometry as the geometry of physical space to be proven wrong. Also Einstein in his book "Relativity the Special and General Theory", had seemed to think that there could be no definition of simultaneity that could be measured.

If that early 20th century thinking (by the Vienna Circle and Einstein) has later been shown to be wrong, then I'd be interested to knowing.

 

[martinbn]

If that early 20th century thinking (by the Vienna Circle and Einstein) has later been shown to be wrong, then I'd be interested to knowing.

It hasn't.

 

[Dale]

He also has a paper in the Foundations of Physics Journal which seems to me to be in the Clarivate Master Journal List
Proper-Time Formulation of Relativistic Dynamics (Found. Phys. 31, Issue 9, Sep 2001, Pages 1357 - 1400)

This is a better reference, let’s stick with this. This journal is a second or third tier physics journal, with a journal Eigenfactor ranked 45 out of 79. So it is acceptable to discuss here, but it should be remembered that this sort of journal is one that people publish in after being rejected by the first or second tier journals.

Unfortunately, it is behind a paywall and there does not seem to be a free version in my usual sources. So I am unable to judge that specific article. If it continues with the space proper-time concept then it is subject to the criticism I mentioned above.

 

[name123]

It hasn't.

Why has AEST not offered a viable model compatible with the idea of Euclidean geometry being the geometry of physical space?

 

[name123]

This is a better reference, let’s stick with this. This journal is a second or third tier physics journal, with a journal Eigenfactor ranked 45 out of 79. So it is acceptable to discuss here, but it should be remembered that this sort of journal is one that people publish in after being rejected by the first or second tier journals.

Unfortunately, it is behind a paywall and there does not seem to be a free version in my usual sources. So I am unable to judge that specific article. If it continues with the space proper-time concept then it is subject to the criticism I mentioned above.

There is the other paper which I mentioned, by the same author, which can be freely read...

 

[Dale]

Also not sure what you mean by space-propertime having no physical meaning

I mean that a single point in space-propertime is not a single well defined concept. This is in distinction to spacetime where a point in spacetime is clear and well defined. To me, building up a concept where the primitive element of that space is poorly defined can only lead to a poorly defined concept.

There is the other paper which I mentioned, by the same author, which can be freely read...

And which also does not meet our usual quality standards.

 

[PeroK]

Also Einstein in his book "Relativity the Special and General Theory", had seemed to think that there could be no definition of simultaneity that could be measured.

The issue is that there is no invariant definition of simultaneity. Einstein, in fact, established the Einstein clock synchronization convention (for defining and measuring simultaneity in a given inertial reference frame). Ironically, we are often faced with the argument on here that this is the only valid simultaneity convention.

 

[name123]

The issue is that there is no invariant definition of simultaneity. Einstein, in fact, established the Einstein clock synchronization convention (for defining and measuring simultaneity in a given inertial reference frame). Ironically, we are often faced with the argument on here that this is the only valid simultaneity convention.

But with AEST I was thinking the simultaneity definition would be if they were simultaneous in proper time. Not to do with clocks (because of time dilation). But that both the clock values, and the proper time value could be worked out.

 

[name123]

I mean that a single point in space-propertime is not a single well defined concept. This is in distinction to spacetime where a point in spacetime is clear and well defined. To me, building up a concept where the primitive element of that space is poorly defined can only lead to a poorly defined concept.

And which also does not meet our usual quality standards.

But I went on to give you an example. And mentioned that in the Epstein explanation by David Eckstein (David Eckstein Relativity search should find it), in the Epstein section (4.2 or C2) it seems to have an example where "A and B met at O and at that point both set their clocks to zero", and it shows how to use the diagram to predict time dilation, length contraction etc. It also seems to go onto indicate what is meant by propertime in C3 'Clocks that got synchronized at the meeting in O will any time later be located on a half circle centered in O. I would suggest the name synchrone for such a half circle. Both events, "Black reaching the space-time-position A" and "Red reaching the space-time-position B" are simultaneous for Black and Red, however both are telling us that the reading of the other's clock lies behind'

It seems to me that the point in spacetime where A and B are located on the half circle is well defined, and that what each state their location is, and what their clock reads, and what the other's location is and what the other's clock reads can be given, and agrees with TR's predictions.

 

[PeroK]

But with AEST I was thinking the simultaneity definition would be if they were simultaneous in proper time. Not to do with clocks (because of time dilation). But that both the clock values, and the proper time value could be worked out.

Yes, I understand. There would be a single, absolute measure of simultaneity of any two events. Given what we know from SR then mathematically something has got to give. So, I'm not surprised by Dale's point:

I mean that a single point in space-propertime is not a single well defined concept. This is in distinction to spacetime where a point in spacetime is clear and well defined. To me, building up a concept where the primitive element of that space is poorly defined can only lead to a poorly defined concept.

This is the mathematical trick that circumvents the relativity of simultaneity. There are always mathematical tricks that can undermine any definitive statement. If you look at SR, there is an assumption that if particle A collides with particle B, then that is a single event. This essentially forces simultaneity every time they collide. Whereas, their clocks readings may show different elapsed proper times between collisions.

If you relax that assumption and allow the collision of particles A and B to be two non-simultanenous events, then you undermine the assumptions (essentially by redefining simultaneity).

In short, by changing the definition of simultaneity, you remove one of the assumptions that led to Einstein's conclusion.

 

[Mister T]

TL;DR Summary: Asking whether AEST (Absolute Euclidean Spacetime) models work, in the sense of giving the correct predictions?

the new gravitational dynamics and electrodynamics are reformulated in close correspondence with classical physics, and subsequently leads to the correct predictions for the deflection of light and the precession of perihelia while being based on a flat spacetime.

This is a clue that there's something wrong. The advance of the perihelion of Mercury, and the bending of starlight that grazes the sun were considered verification of Einstein's theory, but that was over 100 years ago. It's ancient history. Since then there has been a plethora of observations and experiments that confirm Einstein's theory much more convincingly. Any new theory of gravity would have to explain those observations and experimental results, too.

I encourage you to do a google search of Clifford M. Will and look at the publications and videos. Einstein's theory is not consistent with Euclidean geometry.

And by the way, the spacetime of special relativity is flat, but is non-Euclidean.

 

[name123]

Yes, I understand. There would be a single, absolute measure of simultaneity of any two events. Given what we know from SR then mathematically something has got to give. So, I'm not surprised by Dale's point:This is the mathematical trick that circumvents the relativity of simultaneity. There are always mathematical tricks that can undermine any definitive statement. If you look at SR, there is an assumption that if particle A collides with particle B, then that is a single event. This essentially forces simultaneity every time they collide. Whereas, their clocks readings may show different elapsed proper times between collisions.

If you relax that assumption and allow the collision of particles A and B to be two non-simultanenous events, then you undermine the assumptions (essentially by redefining simultaneity).

In short, by changing the definition of simultaneneity, you remove one of the assumptions that led to Einstein's conclusion.

But as I understand it (and my understanding is admittedly sketchy), with AEST if particle A collides with particle B then that would be a single event which would be simultaneous for both A and B in proper time also. And clocks could be set to 0, and later when at a given point considered simultaneous in proper time, the clock values of A and B could be given from each perspective, and what those values would be would agree with SR.

 

[name123]

This is a clue that there's something wrong. The advance of the perihelion of Mercury, and the bending of starlight that grazes the sun were considered verification of Einstein's theory, but that was over 100 years ago. It's ancient history. Since then there has been a plethora of observations and experiments that confirm Einstein's theory much more convincingly. Any new theory of gravity would have to explain those observations and experimental results, too.

I encourage you to do a google search of Clifford M. Will and look at the publications and videos. Einstein's theory is not consistent with Euclidean geometry.

And by the way, the spacetime of special relativity is flat, but is non-Euclidean.

Could you possibly point out some finding that you or Clifford M. Will think AEST is not compatible with?
Or are you claiming that AEST is not consistent with Euclidean geometry?
And with AEST the spacetime with gravity is also flat I think.
Flat Space Gravitation (Found. Phys. 35, Issue 9, Sep 2005, Pages 1543 - 1562)
(again by J.M.C Montanus)

 

[PeroK]

But as I understand it (and my understanding is admittedly sketchy), with AEST if particle A collides with particle B then that would be a single event which would be simultaneous for both A and B in proper time also. And clocks could be set to 0, and later when at a given point considered simultaneous in proper time, the clock values of A and B could be given from each perspective, and what those values would be would agree with SR.

If proper time is to mean anything then each particle keeps proper time and events are simultaneous if they have the same proper time. The problem with that is that A and B can collide twice, once when both clock's read zero. Same space-propertime event. Then, the next time, their clocks may read different proper times. Therefore, the second collision is two space-propertime events (one for A and one for B). And so A colliding with B (from A's perspective) is a different event from A colliding with B from B's perspective.

If not, then what is "proper time"?

 

[name123]

If proper time is to mean anything then each particle keeps proper time and events are simultaneous if they have the same proper time. The problem with that is that A and B can collide twice, once when both clock's read zero. Same space-propertime event. Then, the next time, their clocks may read different proper times. Therefore, the second collision is two space-propertime events (one for A and one for B). And so A colliding with B (from A's perspective) is a different event from A colliding with B from B's perspective.

If not, then what is "proper time"?

Sorry my mistake, I used the term proper time to mean absolute time.

So let me re-write. As I understand it, theories like AEST allow a definition of simultaneity in absolute time. But if A and B collide then they are obviously simultaneous in absolute time. If A and B collide again, again that would be a simultaneous event in absolute time, even though in the proper time of A it can be different to the proper time of B. But AEST can give the proper time of A and B, and explain why the events are simultaneous in absolute time. Also if A and B don't collide again, AEST can still state at which points A and B are simultaneous in absolute time.

If you were to search for Euclidean Relativity, I am sure you could find a site which links papers, which would outline what is being stated. It isn't just the idea that any frame of reference could be thought of as being absolute time. As I understand it, it is that all things are being thought to move at the speed of light. Nothing moves faster, nothing moves slower, but things do move in different directions in a flat Euclidean geometry.

 

[Ibix]

Just to be clear, we're talking about the kind of $x,\tau$ diagram where the Euclidean length of the line is $\Delta t$?

Of course you can get all the regular SR results out of it - it's just that instead of basing everything on $\Delta \tau^2=\Delta t^2-\Delta x^2$ it bases everything on $\Delta\tau^2+\Delta x^2=\Delta t^2$, so it's just an alternative interpretation. I think it's a much inferior one, since you can't interpret the diagram as a map of spacetime because a single event can appear at multiple locations. That means that it's really hard to do any actual physics in this interpretation, and I can't see any upsides. It might be a useful representation in specific circumstances, but I can't see how it could be generally useful.

 

[Mister T]

Could you possibly point out some finding that you or Clifford M. Will think AEST is not compatible with?

Radar ranging of Venus.

 

[name123]

Radar ranging of Venus.

Why what does AEST predict?

 

[Ibix]

Why what does AEST predict?

I don't think it can predict anything. As far as I can see, to be able to reinterpret the metric in this Euclidean fashion requires a hypersurface orthogonal time coordinate with a constant $tt$ metric component and a Euclidean metric on the spacelike planes, which you don't have in this case. (That is, it only works in flat spacetime because it's a mathematical trick that relies on the properties of particular types of global coordinate schemes that only fit flat spacetime.)

 

[Dale]

with AEST if particle A collides with particle B then that would be a single event which would be simultaneous for both A and B in proper time also

That is a misunderstanding, and is exactly the problem with space proper time. When A and B collide they do not necessarily have the same proper time. For example, in the twins scenario, when they reunite. So the reunion event, where the twins meet, is two different points in space-propertime.

Frankly, the “benefit” one gets by using a Euclidean metric is far outweighed by the disadvantage of not being able to tell when things collide.

Also, as far as I can tell there is no causal structure to space-propertime

 

[Mister T]

Why what does AEST predict?

I don't know. I was just pointing out that the bending of starlight and the advance of the perihelion of Mercury were touted as great confirmations of general relativity, and that since that time many many more experiments have been done with far far greater precision. That means they are primarily of historical significance.

So a paper written in the 21st century claiming to explain those two observations from over 100 years ago, and ignoring all the far more precise observations and experiments that have been done in the last 100 years, is highly suspect.

 

[Dale]

But I went on to give you an example.

Yes, which is why I stated that you had a misunderstanding. Your example is wrong. Space-propertime doesn’t work the way you claim it does.

it seems to have an example where "A and B met at O and at that point both set their clocks to zero"

Yes, you can pick one event, say the departure, to coincide in space-propertime. But then the reunion will be two separate points. That is the problem.

 

[Ibix]

Just to illustrate @Dale's point, consider a kind of repeated twin paradox. We have triplets, one who stays at home (purple), one who travels at 0.6c (red) and one who travels at 0.8c (blue). At time zero the travellers set off and return simultaneously at some later time, shake hands, turn around and repeat their trips. Below is a regular Minkowski diagram (left) and an Epstein diagram (right)

Note how you can't see from the right hand diagram that the travellers meet at home. And if you want to do something like add radar pulses to illustrate the Doppler analysis of the twin paradox, you can't do it. Light like lines satisfy $x=t+\mathrm{const}$ so ought to be drawn horizontally, but then how do you draw a radar pulse reflecting off something and returning? That's what I meant about not really being able to do actual physics in this scheme.

 

[PeroK]

Just to illustrate @Dale's point, consider a kind of repeated twin paradox. We have triplets, one who stays at home (purple), one who travels at 0.6c (red) and one who travels at 0.8c (blue). At time zero the travellers set off and return simultaneously at some later time, shake hands, turn around and repeat their trips. Below is a regular Minkowski diagram (left) and an Epstein diagram (right)
View attachment 317608View attachment 317609
Note how you can't see from the right hand diagram that the travellers meet at home. And if you want to do something like add radar pulses to illustrate the Doppler analysis of the twin paradox, you can't do it. Light like lines satisfy $x=t+\mathrm{const}$ so ought to be drawn horizontally, but then how do you draw a radar pulse reflecting off something and returning? That's what I meant about not really being able to do actual physics in this scheme.

Like I said, something's got to give! You want Euclidean spacetime? The simple, logical physical model has got to go.

 

[Dale]

Light like lines satisfy x=t+const so ought to be drawn horizontally, but then how do you draw a radar pulse reflecting off something and returning? That's what I meant about not really being able to do actual physics in this scheme

Similarly, causes can come after effects in a space-propertime diagram. That makes writing laws of physics almost impossible in terms of space-propertime.

 

[Dale]

And I thought the point was that the length of the lines would be equal, and that would tell you that those events would be simultaneous in absolute time

As I said, you misunderstood the diagrams.

 

[Ibix]

If you look at the 4.7 under the Epstein section in the Epstein explanation by David Eckstein, then he does an Epstein diagram for the twin paradox. And I thought the point was that the length of the lines would be equal, and that would tell you that those events would be simultaneous in absolute time (whether they met up, or whether the traveling twin had carried on and never turned back).

The lengths of the lines are equal. That doesn't say anything about absolute time (there's no such thing), but tells you that they are simultaneous in coordinate time. But I challenge you to recognise that the lengths of the lines are equal without getting a ruler (and a realistic acceleration will make a curve and the diagram will be unusable). And I repeat - how are you going to draw radar pulses on this diagram? It's more of a hindrance than help, IMO.