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setting the Minkowski Spacetime model in motion


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Posted

Rather than defining positions on the diagram as events, define the diagram as representing actual reality in the following manner and then locate the event in the resulting dynamic model.

The hyperplane going through the origin is the present of all space, three dimensional space depicted in two dimensions, .   This hyperplane falls through the dynamic model at 1 sec per second along the z axis.   All past events for the observer at the origin existed above the plane but are visible as photons coming in from all directions, shown on the diagram as the upper light cone. The lower light cone represents photons or signals going out, at light speed from the observer.  These light cones will intersect the falling hyperplane in increasingly large circles, representing the spherical shell of photons.

Movement toward another location in space results in decreasing the time and/or distance between the locations. Both locations fall through time at 1 sec per sec and light travels always at C.

Posted

It is Minkowsky space-time, that already incorporates time ( and the associated dynamics ).
That is the reason for calling them 'events'; The place, and the time, are specified.

If you are having problems understanding Relativity, ask questions, instead.

Posted (edited)
28 minutes ago, tar said:

Rather than defining positions on the diagram as events, define the diagram as representing actual reality in the following manner and then locate the event in the resulting dynamic model.

The hyperplane going through the origin is the present of all space, three dimensional space depicted in two dimensions, .   This hyperplane falls through the dynamic model at 1 sec per second along the z axis.   All past events for the observer at the origin existed above the plane but are visible as photons coming in from all directions, shown on the diagram as the upper light cone. The lower light cone represents photons or signals going out, at light speed from the observer.  These light cones will intersect the falling hyperplane in increasingly large circles, representing the spherical shell of photons.

Movement toward another location in space results in decreasing the time and/or distance between the locations. Both locations fall through time at 1 sec per sec and light travels always at C.

 

How does this work out with world vectors ?

Minkowski was (is) famous for developing geometric solutions and explanations to mechanics  / and dynamics problems (not only relativity), so departing from his 1908 presentation requires a lot of thought.

In particular you can express Maxwellian vector electrodynamics directly in Minkowski's geometric representation, the vectors and especially vector-products, which still work using four-vectors.

 

Note the c is conventionally lower case.
It is not a good idea to start by choosing new and unusual symbols for something everyone agrees on.

Particularly as Einstein's paper was entitled

"On the electrodynamics of moving bodies"

As such it was about marrying Newton and Maxwell (metaphorically).

And, of course, C is used conventionally for the electric field and the quantity capacitance.
 

Edited by studiot
Posted

Studiot,

Thankyou.

I have not completely translated all or any for that manner equations derived from the original definitions of Minkowski space.  I will endeavor to seek out a particular said equation with vectors and such and show that the relativity equations derived from original definitions would be equally obtainable using the dynamic model that I am using without deforming space or dilating time.

Regards, TAR

I am a big fan of geometric solutions.

MigL,

I have been trying to understand relativity, without requiring time dilation and length compression.  I am not using the Minkowski diagram as the Minkowski diagram.  I just noticed my thought has the future below and the past above, so it might be hard to true everything up in terms of equations, but I was trying to use a model or picture everyone has in their head as a basis for discussion.  Since the Minkowski diagram is used to show how space deforms and time dilates and I don't require space or time to act in that fashion to comprehend relativity, I am thinking that things might work out mathematically with redefinitions of here and now and then and there and how you get between the two.

Regards TAR

Posted
1 hour ago, tar said:

Studiot,

Thankyou.

I have not completely translated all or any for that manner equations derived from the original definitions of Minkowski space.  I will endeavor to seek out a particular said equation with vectors and such and show that the relativity equations derived from original definitions would be equally obtainable using the dynamic model that I am using without deforming space or dilating time.

Regards, TAR

I am a big fan of geometric solutions.

MigL,

I have been trying to understand relativity, without requiring time dilation and length compression.  I am not using the Minkowski diagram as the Minkowski diagram.  I just noticed my thought has the future below and the past above, so it might be hard to true everything up in terms of equations, but I was trying to use a model or picture everyone has in their head as a basis for discussion.  Since the Minkowski diagram is used to show how space deforms and time dilates and I don't require space or time to act in that fashion to comprehend relativity, I am thinking that things might work out mathematically with redefinitions of here and now and then and there and how you get between the two.

Regards TAR

 

I wonder, have you been following the discussion with another member about the geometric interpretation embodied in Minkowski ?

Why is the time axis in a space-time diagram a distance - Relativity - Science Forums

 

Relativity without time dilation or length contraction ?

That is Galilean or Newtonian relativity. The thread I linked to has got as far as that.

The problem with Galilean relativity and why it had to be abandoned , except at low speeds and locally, some of its predictions are in direct conflict with observations that late nineteenth century scientists made and subsequently more recent scientists have made to much greater precision.

 

It is too long to reproduce here but I can email an English translation  of the paper delivered to the 80th assembly of the German Natural Scientists and Physicians at Cologne in 1908, by H Minkowski, shortly before his untimely early death from appendicitis.

If you want a scan of the paper, let me have an email address that can accept jpgs of up 1M by private message.

I would recommend reading the paper as I think you would find it accessible (ie not too mathematical or high powered, no offence) he was a natural at explaining his points.

Posted
On 11/22/2021 at 3:49 PM, studiot said:

 

I wonder, have you been following the discussion with another member about the geometric interpretation embodied in Minkowski ?

Why is the time axis in a space-time diagram a distance - Relativity - Science Forums

 

Relativity without time dilation or length contraction ?

That is Galilean or Newtonian relativity. The thread I linked to has got as far as that.

The problem with Galilean relativity and why it had to be abandoned , except at low speeds and locally, some of its predictions are in direct conflict with observations that late nineteenth century scientists made and subsequently more recent scientists have made to much greater precision.

 

It is too long to reproduce here but I can email an English translation  of the paper delivered to the 80th assembly of the German Natural Scientists and Physicians at Cologne in 1908, by H Minkowski, shortly before his untimely early death from appendicitis.

If you want a scan of the paper, let me have an email address that can accept jpgs of up 1M by private message.

I would recommend reading the paper as I think you would find it accessible (ie not too mathematical or high powered, no offence) he was a natural at explaining his points.

Thank you,

I am rereading and reevaluating the arguments and math presented in Relativity and Common Sense, A New Approach to Einstein, written by Herman Bondi and published 1964.    This, in an effort to answer your previous vector question. 

I am not saying that the equations of relativity give you wrong results, I am saying that the definitions and assumptions and the dropping and adding of dimensions can lead one to incorrect mathematical interpretations.  In my imagination, I follow the travels of Alfred, Brian and Edgar, as they fly around syncing their watches upon meeting and sending out pulses every four seconds and following their pulses toward the next observer.  I am never satisfied, in the descriptions, that the situation cannot be understood WITHOUT any time dilation or length contraction.  In my interpretation, there is still private time and public time, or proper time, but HOW clocks are synced, and why is not done in what I consider a logical fashion.

In my interpretation proper time is the universal time I talk about and private time is the local now I talk about.  To me, the rest of the universe is experiencing only one thing at a time and that time is now.  Things that happened before everywhere have already happened and will not happen again in exactly the same combination, because things change with time.  Thing we see and experience in our local now are the effects of what happened before.  We see the images and feel the vibrations of the things around us.  Close things first, far things later, really far things never because we don't live long enough to see them arrive in our now.  But the past has already happened and the past constructs our present and the present of every other location.  Nothing  happens in isolation.  And the future has not happened yet, anywhere.

So please give me a little time to finish Bondi and try to learn some of the transforms so I can transform the transforms into my space.  I do not think the equations of relativity are wrong.

Posted
36 minutes ago, tar said:

Thank you,

I am rereading and reevaluating the arguments and math presented in Relativity and Common Sense, A New Approach to Einstein, written by Herman Bondi and published 1964.    This, in an effort to answer your previous vector question. 

I am not saying that the equations of relativity give you wrong results, I am saying that the definitions and assumptions and the dropping and adding of dimensions can lead one to incorrect mathematical interpretations.  In my imagination, I follow the travels of Alfred, Brian and Edgar, as they fly around syncing their watches upon meeting and sending out pulses every four seconds and following their pulses toward the next observer.  I am never satisfied, in the descriptions, that the situation cannot be understood WITHOUT any time dilation or length contraction.  In my interpretation, there is still private time and public time, or proper time, but HOW clocks are synced, and why is not done in what I consider a logical fashion.

In my interpretation proper time is the universal time I talk about and private time is the local now I talk about.  To me, the rest of the universe is experiencing only one thing at a time and that time is now.  Things that happened before everywhere have already happened and will not happen again in exactly the same combination, because things change with time.  Thing we see and experience in our local now are the effects of what happened before.  We see the images and feel the vibrations of the things around us.  Close things first, far things later, really far things never because we don't live long enough to see them arrive in our now.  But the past has already happened and the past constructs our present and the present of every other location.  Nothing  happens in isolation.  And the future has not happened yet, anywhere.

So please give me a little time to finish Bondi and try to learn some of the transforms so I can transform the transforms into my space.  I do not think the equations of relativity are wrong.

 

Good to hear back from you.

There is certainly a measure of truth in what you are saying.

The equations of Einstein are not wrong, but they are not totally right either.

Indeed he changed them a few times himself, in acknowledgement of this.

Further he made some incorrect predictions.

You are correct in wondering about the interpretation of the Mathematics, dimensions etc.

Spacetime is only a (mathematical) model.

It is not the real thing.

Its equations are not wrong, but being a model its equations also require certain results that do not appear in reality.

There is a (much) less mathematical discussion in progress about this right now, including ssome excellent links to Einstein's incorrect predictions about length contraction.

 

 

Posted

Minkowski space-time does not need a fundamental re-think. The reason why is the very same reason why understanding foreshortening of an object's length when one's holding it in a peculiar position doesn't need a fundamental re-think. It requires us to understand the laws of perspective and observer dependence of measured quantities.

Lorentz-Fitzgerald scaling laws are laws of forshortening in space-time, just because going from one inertial reference system to another is like rotating in space-time. Simple as that. Simple is one thing, easy to accomodate in daily-life intuitions is quite another.

A very different thing would be asking where space-time itself comes from, why 1+3 dimensions, what the limits of validity of pseudo-Euclidean geometry, or Einstein's GR. But not the build-up of how these laws apply in the ordinary range of validity in distances, energies, times, etc.

Posted
1 hour ago, joigus said:

Lorentz-Fitzgerald scaling laws are laws of forshortening in space-time, just because going from one inertial reference system to another is like rotating in space-time. Simple as that. Simple is one thing, easy to accomodate in daily-life intuitions is quite another.

 

You may wish to expand on this statement as i think it is easily capapble of misinterpretation.

Posted
1 hour ago, studiot said:

 

You may wish to expand on this statement as i think it is easily capapble of misinterpretation.

Gladly, Studiot. Thank you for your interest. Here's a couple of comments from yours truly that deal on this same comparison:

 

Posted
1 hour ago, joigus said:

Gladly, Studiot. Thank you for your interest. Here's a couple of comments from yours truly that deal on this same comparison:

I wasn't asking for myself, but thanks for your links.

I was gently referring to the invariance of 4 dimensional distance in spacetime.

Distance or length in 4 dimensions is the invariant '4 squares quantity'

No one measures it lengthened or shortened.

3 dimensional distance is measured as shortened by many observers (but not all)

And , of course time is then measured as lengthened.

But I'm sure you know all this.

My point is that many others mix up which distance they are foreshortening.

Posted (edited)

Ok. I'm sorry if I missed a particularly subtle point you made. The OP seems to be under the impression that special relativity demands us to admit that space 'deforms'.

I was just trying to be helpful, because I think that's an unfortunate misconception.

On 11/22/2021 at 7:49 PM, tar said:

I have not completely translated all or any for that manner equations derived from the original definitions of Minkowski space.  I will endeavor to seek out a particular said equation with vectors and such and show that the relativity equations derived from original definitions would be equally obtainable using the dynamic model that I am using without deforming space or dilating time.

(my emphasis.)

Wrong!!! That's what I'm trying to address. And believe me, we've all been there at some point.

Even though I'm under heavy workload, believe me; I wanna be helpful. So I've made a little drawing that explains why that's wrong based on my analogy with foreshortening in space.

foreshortening_explanation.png.f5092587417986363eb81017a524d341.png

Nothing is deformed. Space is not deformed. The object is not deformed. Yet, foreshortening is real enough that, if you don't take it into account, you're going to damage the paint from the frame of your garage's door, and the ladder, or worse. The explanation that special relativity gives of this is just common sense. Common sense gets you a long way. One must study special relativity and there comes a moment when you naturally understand it, and there's no looking back.

That's what I meant.

Edited by joigus
significant qualification
Posted
On 11/22/2021 at 1:49 PM, tar said:

I will endeavor to seek out a particular said equation with vectors and such and show that the relativity equations derived from original definitions would be equally obtainable using the dynamic model that I am using without deforming space or dilating time.

 

23 hours ago, tar said:

I do not think the equations of relativity are wrong.

These statements are incompatible, because the equations of relativity show that length and time are quite clearly relative 

Posted
23 hours ago, tar said:

I am rereading and reevaluating the arguments and math presented in Relativity and Common Sense, A New Approach to Einstein, written by Herman Bondi and published 1964.    This, in an effort to answer your previous vector question. 

 

I am not sure how much you will find about vectors in Bondi's book, but the Einstein train experiments chapter is worth thinking about.

 

Here is another train experiment which shows some interesting things.

 

A man holding two bricks is travelling in a glass train. (Glass so he can see and be seen)

He holds them side by side, one just inside the carriage and one just outside by the window.

As he passes another man standing on a station platform he drops them both together.

 

It is illuminating to consider what each man sees about the paths of the two bricks.

Posted
On 11/29/2021 at 7:37 AM, swansont said:

 

These statements are incompatible, because the equations of relativity show that length and time are quite clearly relative 

Perhaps, perhaps not.

You believe time is route dependent.  I do not,

On 11/29/2021 at 8:04 AM, studiot said:

 

I am not sure how much you will find about vectors in Bondi's book, but the Einstein train experiments chapter is worth thinking about.

 

Here is another train experiment which shows some interesting things.

 

A man holding two bricks is travelling in a glass train. (Glass so he can see and be seen)

He holds them side by side, one just inside the carriage and one just outside by the window.

As he passes another man standing on a station platform he drops them both together.

 

It is illuminating to consider what each man sees about the paths of the two bricks.

the both bricks would fall in a parabola  for the guy on the platform and straight down for the guy in the train

I am unsure about the chapter where a boat is crossing a river at 5 miles and hour, pointed upstream so he gets to the shore across. Bondi says the effective speed is 4 miles an hour, but he confuses the amount of water traveled, with the distance to the other shore.  This is crucial to not get confused because time flows like a river.  You are carried downstream no matter what your angle of approach.  That is, the water you first were on is downstream by the time you get anywhere.  Consider a conveyor belt you would like to cross holding a marker touching the belt.  The line you make would be a diagonal line of a particular length, longer than the distance across.

In the various travels of Alfred and Charles, Hermann always resyncs clocks when the travelers are passing.  I think if you properly sync the clocks at the start, there would be no need.

Posted
20 minutes ago, tar said:

Perhaps, perhaps not.

You believe time is route dependent.  I do not,

I'm unsure as to what you mean by "route dependent"

I know that if a clock moves, it runs slow relative to another clock, and that this is both (1) experimentally confirmed and (2) in accordance with the predictions of relativity

I don't care what you believe to be true. I want to know what you can demonstrate to be true.

Posted
8 minutes ago, swansont said:

I'm unsure as to what you mean by "route dependent"

I know that if a clock moves, it runs slow relative to another clock, and that this is both (1) experimentally confirmed and (2) in accordance with the predictions of relativity

I don't care what you believe to be true. I want to know what you can demonstrate to be true.

I have a question about how you sync moving clocks.  

for instance, if you sync a clock from here and the clock is 30 centimeters from here and you want it to read the same time when you get to it or it to you you have to send it the count on your clock and tell it to add a nanosecond to your count so that both clocks are reading the same proper time.

if you sync all clocks at the start of the experiment to read the same proper time, according to their distance from a master clock, then moving toward another clock you would see a blue shift but the lag in time would be gone by the time you were in the same spot.

Thank you Joigus for your time.

I got it a few times but there is looking back and not getting it.

I would explain, but a bot keeps preventing me.

Posted
39 minutes ago, tar said:

I have a question about how you sync moving clocks.  

for instance, if you sync a clock from here and the clock is 30 centimeters from here and you want it to read the same time when you get to it or it to you you have to send it the count on your clock and tell it to add a nanosecond to your count so that both clocks are reading the same proper time.

Yes.

39 minutes ago, tar said:

if you sync all clocks at the start of the experiment to read the same proper time, according to their distance from a master clock, then moving toward another clock you would see a blue shift but the lag in time would be gone by the time you were in the same spot.

You can compare the phase (time) not frequency. If a clock is running slow, it accumulates phase more slowly. If it runs slow for a longer period, a larger phase difference accumulates. 

Posted

the count or phase is similar to frequency in that each peak represents one count or tick

if there is a certain amount of ticks per second that is the frequency

my contention is that a light wave of a certain frequency does not change in reference to the universe

that is it is doing what it is doing regardless of who or what notices it 

if you are moving in the same direction as the wave the ticks will be red shifted

if you are moving toward the light the ticks will be blue shifted

no time is warped

no distance is warped

 

Posted
On 11/30/2021 at 5:54 PM, tar said:

I am unsure about the chapter where a boat is crossing a river at 5 miles and hour, pointed upstream so he gets to the shore across. Bondi says the effective speed is 4 miles an hour, but he confuses the amount of water traveled, with the distance to the other shore.  This is crucial to not get confused because time flows like a river.  You are carried downstream no matter what your angle of approach.  That is, the water you first were on is downstream by the time you get anywhere.  Consider a conveyor belt you would like to cross holding a marker touching the belt.  The line you make would be a diagonal line of a particular length, longer than the distance across.

 

 

Did you mean this piece ?   (From the 1964 edition)

In future it would be very helpful to refer to the page(s) from the book.

This is a discussion of Newtonian-Galilean mechanics, not Einstinian relativity.

 

bondi1.jpg.338fa1e68aeae7adf62b11cd651fa74c.jpg

 

Quote

Bondi says the effective speed is 4 miles an hour,

 

Actually he says the effective speed is 4 miles an hour for crossing the river.

I think I understand you worry though.

Bondi could have perhaps worded his text a little more clearly but technically he is correct.

Here is my explanation, I hope it helps.

 

In all such problems it is essential to qualify or specify the word 'speed' as there are several different speeds involved.
I am not sure that using 'effective' is a good choice but since we are presented with it I will use it.

The boat is stated to travel through still water at 5 mph.
I have seen the terms 'actual speed' or 'real speed applied', but the best (clearest) term is 'the speed through the water is 5mph'.

But remember that the water is not still.

I would also like to make it very clear that you are mistaken in saying that the boat travels further than the width of the river.

The boat travels exactly the width of the river, no more and no less.
It does not travel in some curved path, whcih would be longer.

This is because our frame of reference is the ground, not the water.

So perhaps Bondi might have said that the speed, relative to the ground when directly crossing the river is 4mph, rather than calling it the effective speed.

So we have a situation that the boat has a speed relative to the ground and the water has a speed relative to the ground.
The first of these we don't know, but must calculate.
The second we are told as being 3mph.
These two speeds can be composed to eliminate the ground to obtain the speed of the boat relative to the water, and we are told this.

This composition is done using an ordinary vector triangle or parallelogram which can be done.

 

I will stop there and post since you have just come on line.

Posted

I think I am not clear on what is standing for what in the river analogy.

One of the confusions in my understanding of relativity is when distance is used in a spacelike way and when it is used in a time like way. 

My solution is to consider…

My entry screen is confounded.  Even in word.

Posted
12 minutes ago, tar said:

I think I am not clear on what is standing for what in the river analogy.

An analogy is a way to explain, by way of a story; what standing for what, is the data on which the story is based; you can't cross the same river twice, yet we do so everyday...

Posted
1 hour ago, tar said:

the count or phase is similar to frequency in that each peak represents one count or tick

if there is a certain amount of ticks per second that is the frequency

my contention is that a light wave of a certain frequency does not change in reference to the universe

Claiming this means you reject relativity, because there are no absolute frames in relativity, and relativity allows you to compare the observation of different frames.

You would need to provide evidence of this absolute frame.

1 hour ago, tar said:

that is it is doing what it is doing regardless of who or what notices it 

if you are moving in the same direction as the wave the ticks will be red shifted

if you are moving toward the light the ticks will be blue shifted

Which has nothing to do with being “in reference to the universe”

It’s just your motion relative to the source 

 

1 hour ago, tar said:

no time is warped

no distance is warped

 

Repeating this doesn’t make it true. Why can’t you provide experimental evidence to support you claims?

30 minutes ago, tar said:

when distance is used in a spacelike way and when it is used in a time like way. 

What does this mean?

Posted
On 12/4/2021 at 9:31 AM, dimreepr said:

An analogy is a way to explain, by way of a story; what standing for what, is the data on which the story is based; you can't cross the same river twice, yet we do so everyday..

understood, but there is a difference considering the distance traveled relative to the river bottom and the distance traveled relative to the surface.

there is disagreement as to what it is that light is crossing

the ether is both proved and disproved

in an experiment or an analogy you have to agree on what IS space

are you crossing the river bottom or are you traveling across the surface

 

 

Posted
20 minutes ago, tar said:

he ether is both proved and disproved

No, the ether was abandoned when it failed to predict the behavior observed in the Michelson-Morley experiment. It was disproved.

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