If correct: a catastrophe in the Lorentz transformation

[aawahab76]

No, "simultaneous relative to an observer" is normally just a shorthand for "simultaneous in the observer's inertial rest frame", unless you're talking about the observer seeing the light from some pair of events simultaneously with their eyes (for example, if one star 200 light-years away in Earth's frame exploded in 1800, and another star 100 light-years away exploded in 1900, then on Earth we would see the light from these explosions simultaneously in 2000).

So at 1 sec in F, all space (as represented by x coordinate) is filled with events (being empty for example except at 10^100 m). However, space as it is is a physical structre that exist irrespictive of any coordinate and at this moment in F, P is being registered in x=10^100 m. But this space is already filling the F' space itself and as such it must be registered in the x' coordinte but after O,O' event as I can picture it (this is possibly where intuition come on). I am sure you may say that what I am saying is just with respect to a particuler frame that I find some how "intuitiv" but notice how we are now speaking about the totality of events (all x's) registered by a particuler frame at its global time coordinate rather than a single event.

 

[JesseM]

So at 1 sec in F, all space (as represented by x coordinate) is filled with events (being empty for example except at 10^100 m). However, space as it is is a physical structre that exist irrespictive of any coordinate and at this moment in F, P is being registered in x=10^100 m.

I don't understand what you mean by this. The statement "at this moment in F" is not one that's "irrespective of any coordinate", because talking about what's happening at different locations at a particular "moment" has no meaning outside the context of a particular coordinate system (unless you believe in some coordinate-independent notion of absolute simultaneity).

But this space is already filling the F' space itself and as such it must be registered in the x' coordinte but after O,O' event

Your phrasing is difficult to follow--when you say "it must be registered in the x' coordinate", what is the "it", is it event P? If so, by "registered in the x' coordinate" do you just mean P is assigned some coordinates in the primed frame?

 

[aawahab76]

I don't understand what you mean by this. The statement "at this moment in F" is not one that's "irrespective of any coordinate", because talking about what's happening at different locations at a particular "moment" has no meaning outside the context of a particular coordinate system (unless you believe in some coordinate-independent notion of absolute simultaneity).

Your phrasing is difficult to follow--when you say "it must be registered in the x' coordinate", what is the "it", is it event P? If so, by "registered in the x' coordinate" do you just mean P is assigned some coordinates in the primed frame?

"It" means all of space (in this case 1D space covering the whole x-axis in F and x'-axix in F').

 

[aawahab76]

I don't understand what you mean by this. The statement "at this moment in F" is not one that's "irrespective of any coordinate", because talking about what's happening at different locations at a particular "moment" has no meaning outside the context of a particular coordinate system (unless you believe in some coordinate-independent notion of absolute simultaneity).

Your phrasing is difficult to follow--when you say "it must be registered in the x' coordinate", what is the "it", is it event P? If so, by "registered in the x' coordinate" do you just mean P is assigned some coordinates in the primed frame?

Sorry, but for the first paragraph (and excuse me for this but I do not know how to quote in the appropriate way, one may help here) yes why can't we define absolute simultaneity using t in F and t' in F' so event (t,x) is simultaneous with (t,y) for what ever x and y.

 

[darkhorror]

Sorry, but for the first paragraph (and excuse me for this but I do not know how to quote in the appropriate way, one may help here) yes why can't we define absolute simultaneity using t in F and t' in F" so event (t,x) is simultaneous with (t,y) for what ever x and y.

where do you use t' and F"?

 

[JesseM]

Sorry, but for the first paragraph (and excuse me for this but I do not know how to quote in the appropriate way, one may help here) yes why can't we define absolute simultaneity using t in F and t' in F' so event (t,x) is simultaneous with (t,y) for what ever x and y.

Again this isn't clear, as darkhorror said you don't seem to mention the t' coordinates of either event, and how is "using t in and t' in F' " supposed to give an absolute definition of simultaneity? "Absolute" here means something that all observers can agree on, but obviously a pair of events that have the same t-coordinate have different t'-coordinates and vice versa.

 

[aawahab76]

where do you use t' and F"?

t' is the time coordinate in F' and F'' is a mistake I corrected above, it is F'. Thanks darkhorror

 

[darkhorror]

I wasn't actually talking about the " vs ', the naming of them doesn't really matter. But where do you mention t' and F' after you say that there is that frame? you only mention (t,x) and (t,y).

 

[aawahab76]

I wasn't actually talking about the " vs ', the naming of them doesn't really matter. But where do you mention t' and F' after you say that there is that frame? you only mention (t,x) and (t,y).

That was my bad composition , I mean the following:

why can't we define absolute simultaneity using t in F and t' in F' so:
1- in F, event (t,x) is simultaneous with (t,y) for what ever x and y
2- in F', event (t',x') is simultaneous with (t',y') for what ever x' and y'?

 

[JesseM]

That was my bad composition , I mean the following:

why can't we define absolute simultaneity using t in F and t' in F' so:
1- in F, event (t,x) is simultaneous with (t,y) for what ever x and y
2- in F', event (t',x') is simultaneous with (t',y') for what ever x' and y'?

Because "absolute simultaneity" means a single truth about simultaneity that is the same for all observers. Two events that are simultaneous in F will not be simultaneous when their coordinates are translated into F', and vice versa.

 

[aawahab76]

Because "absolute simultaneity" means a single truth about simultaneity that is the same for all observers. Two events that are simultaneous in F will not be simultaneous when their coordinates are translated into F', and vice versa.

I completely agree as that is resulting from the postulate of special relativity. However, what do you think of the following picture:

1- O (I think it is obvious when O mean the event (0,0) or the observer in x=0, similarly for O' below) built F coordinates using rulers-clocks so whenever the clock at O reads 1 pm (or any other reading), all clocks at the whole space read 1 pm (or the other reading). This can be proved by using your (I think) proposed cameras when the pictures arrive.
2- As in 1, O' built F' so whenever the clock at O' reads 2' pm (or any other reading), all clocks at the whole space read 2' pm (or the other reading).
3- Notice the whole space is a physical entity that is independent of coordinate or frame being used. So usually we have F clock overlapping F' clock (of course the whole structure is imaginary).
4- When O meet O', their respective time coordinates read 0 and 0'. Each observer is certain at this moment that all other clocks (treating those for F independently of those of F') that are covering the whole space are reading the same, in this case 0 and 0'. This again can be proved using the cameras.
5- At the meeting of O and O', P (an explosion) is 1 sec in the future of F. So at the meeting, P is no where in the whole "space" but have already been there according to F'. That is because the reading of the clock at O' when P happened according to F' was -10^81 sec which is certainly before the meeting moment. I am picturing here that all F' clocks at the moment -10^81 sec in F' were reading -10^81 sec and it seems that at least one such clock was overlapping the location of O (the observer) whose clock was certainly before 0 (in F) because O (the event) is in the future.

 

[JesseM]

1- O (I think it is obvious when O mean the event (0,0) or the observer in x=0, similarly for O' below) built F coordinates using rulers-clocks so whenever the clock at O reads 1 pm (or any other reading), all clocks at the whole space read 1 pm (or the other reading). This can be proved by using your (I think) proposed cameras when the pictures arrive.

I don't understand what you mean by "proved". The idea that all clocks show identical readings simultaneously is not an empirical claim, it's just a matter of definition--in SR we have defined the word "simultaneous" in a given frame to mean "same time according to local readings on clocks which have been set according to the Einstein clock synchronization convention". If the observer didn't care about using the definition of simultaneity from inertial frames, he could easily pick a different convention for setting his clocks, and define simultaneity in terms of this new convention. There'd be no reason to judge this alternate definition of simultaneity "wrong" as long as we understand that it no longer matches the definition used in inertial frames (and thus equations of physics that apply in all inertial frames would no longer apply in the non-inertial frame defined by this alternate convention).

3- Notice the whole space is a physical entity that is independent of coordinate or frame being used. So usually we have F clock overlapping F' clock (of course the whole structure is imaginary).

No, I totally disagree, because when you say "the whole space" you mean a snapshot of space at a particular time, but this depends on your simultaneity convention which is not "independent of coordinate or frame being used". The set of events in spacetime is frame-independent, as is the "geometry" of spacetime encoded in the spacetime interval between any pair of events, but there is no single physically correct way to take a 3D cross-section of 4D spacetime and call that "the whole space" at a particular moment.

 

[Dale]

1- O (I think it is obvious when O mean the event (0,0) or the observer in x=0, similarly for O' below) built F coordinates using rulers-clocks so whenever the clock at O reads 1 pm (or any other reading), all clocks at the whole space read 1 pm (or the other reading). This can be proved by using your (I think) proposed cameras when the pictures arrive.
2- As in 1, O' built F' so whenever the clock at O' reads 2' pm (or any other reading), all clocks at the whole space read 2' pm (or the other reading).
4- When O meet O', their respective time coordinates read 0 and 0'. Each observer is certain at this moment that all other clocks (treating those for F independently of those of F') that are covering the whole space are reading the same, in this case 0 and 0'. This again can be proved using the cameras.

Yes, this is fine. In the future you can say this more concisely by saying "F and F' are two inertial frames in the standard configuration". See:
http://en.wikipedia.org/wiki/Lorent...ormation_for_frames_in_standard_configuration

3- Notice the whole [STRIKE]space[/STRIKE] spacetime is a physical entity that is independent of coordinate or frame being used. So usually we have F clock overlapping F' clock (of course the whole structure is imaginary).

As JesseM mentioned, this was incorrect as originally written. I have corrected it in red.

5- At the meeting of O and O', P (an explosion) is 1 sec in the future of F. So at the meeting, P is no where in the whole "space" but have already been there according to F'. That is because the reading of the clock at O' when P happened according to F' was -10^81 sec which is certainly before the meeting moment. I am picturing here that all F' clocks at the moment -10^81 sec in F' were reading -10^81 sec and it seems that at least one such clock was overlapping the location of O (the observer) whose clock was certainly before 0 (in F) because O (the event) is in the future.

Correct. P occurs after O in F and P occurs before O in F'. This is the relativity of simultaneity.

Except for the rather minor edit required for point 3 it seems that you understand what the theory predicts and claims.

 

[aawahab76]

Yes, this is fine. In the future you can say this more concisely by saying "F and F' are two inertial frames in the standard configuration". See:
http://en.wikipedia.org/wiki/Lorent...ormation_for_frames_in_standard_configuration

As JesseM mentioned, this was incorrect as originally written. I have corrected it in red.

Correct. P occurs after O in F and P occurs before O in F'. This is the relativity of simultaneity.

Except for the rather minor edit required for point 3 it seems that you understand what the theory predicts and claims.

No I meant exactly as I wrote "space" not "spacetime". Of course for using LT we will need the "spaetime" but it is my intention here to show that (my)intuition does not find it incorrect to think of 3D section of the whole 4D. I accept that two frames will use different coordinates but Why do you want me to think that at the moment I am writing this replay, I cannot think of a person reading something interesting of his own and being so far from Earth (in a spacelke interval from me) that a picture of him reading that book need 10^100000 light years to arrive to earth. Yes theory of relativity does not accept that or we can say the theory does not have a meaning for that, but that is the theory which even if it works fine, it does not mean it will continue to do so nor does a correct theoy (for now) mean that intuition is wrong. It may or may not be which always leave space for critisicing theories. Again I know that there are more or less subjectivity in intuition meaning but do you really think that the person from far a way (mentioned above) does not exist?

 

[Dale]

No I meant exactly as I wrote "space" not "spacetime".

Then what you meant was wrong. The whole space is not "a physical entity that is independent of coordinate or frame being used". It depends on your simultaneity convention, as JesseM described, which is part of the coordinate system.

I realize that you may think that I am being unkind to point it out so bluntly, but you are mentally stuck until you let go of some incorrect concepts that you are clinging to. Do you honestly believe that you are incapable of being wrong? If not, then consider that this might be one of those instances.

 

[darkhorror]

I would agree, what you need to do is get rid of your preconceived notions of how you think spacetime works. Go back and try to understand what is happening and what is said without how you currently think it should work.

Start with the basics, try and understand how the constant speed of light means a change in things depending on the frame of reference. Go through and understand exactly what the math is saying, where it comes from. Maybe draw out a single scenario in a couple different frames of reference in such a way that you can understand it.

 

[JesseM]

No I meant exactly as I wrote "space" not "spacetime". Of course for using LT we will need the "spaetime" but it is my intention here to show that (my)intuition does not find it incorrect to think of 3D section of the whole 4D. I accept that two frames will use different coordinates but Why do you want me to think that at the moment I am writing this replay, I cannot think of a person reading something interesting of his own and being so far from Earth (in a spacelke interval from me) that a picture of him reading that book need 10^100000 light years to arrive to earth.

Because "at the moment I am writing this reply" has no frame-independent meaning. Again I really recommend you read about the philosophical difference between presentism and eternalism, it seems like your intuitions are based on assuming a presentist notion that the "real world" consists of a bunch of physical objects and events arranged in space in an objective present moment, but the eternalist view of the real world as being spacetime as a whole makes just as much sense. You might also want to take a look at this thread where I discussed similar issues with josephwouk.

Yes theory of relativity does not accept that or we can say the theory does not have a meaning for that, but that is the theory which even if it works fine, it does not mean it will continue to do so nor does a correct theoy (for now) mean that intuition is wrong. It may or may not be which always leave space for critisicing theories. Again I know that there are more or less subjectivity in intuition meaning but do you really think that the person from far a way (mentioned above) does not exist?

It's not that the person far away doesn't exist, it's that all points on his worldline have equal existence--the person at age 13, the person at age 25, the person at age 70, etc. There isn't any single one age that uniquely "exists" because that's his age at the "present", since "present" has no objective frame-independent meaning.

 

[bobc2]

It's not that the person far away doesn't exist, it's that all points on his worldline have equal existence--the person at age 13, the person at age 25, the person at age 70, etc. There isn't any single one age that uniquely "exists" because that's his age at the "present", since "present" has no objective frame-independent meaning.

Excellent explanation! Thanks for that enlightenment.

 

[aawahab76]

I have just seen this paper http://arxiv.org/abs/physics/0203025v1. This is just for your information but I do not know yet if it has any relation to this post.

 

[Dale]

It is just standard LET. Nothing new.

 

[aawahab76]

It is just standard LET. Nothing new.

what is "LET"?

 

[Dale]

Lorentz aether theory. It is an old interpretation of the Lorentz transform. It is experimentally indistinguishable from SR.

 

[Fredrik]

It is just standard LET.

I only spent a couple of minutes skimming through it, but that was enough to see that it also contains at least a few statements that are nothing but crackpot nonsense. The author even claims that "Relativity’s postulates are incompatible with Lorentz Transformation" and ends the paper with "Unless we understand that we are dealing with desynchronized clocks and unless we have in mind the meaning of the definitions we're using, we're likely to continue to make predictions about the physical world that will lead us to incomprehensible paradoxes." This shows that he doesn't understand special relativity, and that he's naive enough to think that relativity really is incomprehensible.

 

[Dale]

I only spent a couple of minutes skimming through it, but that was enough to see that it also contains at least a few statements that are nothing but crackpot nonsense.

That is not too surprising for someone who is not even aware of the LET. I read the abstract and didn't bother with the rest.

 

[GrayGhost]

I only spent a couple of minutes skimming through it, but that was enough to see that it also contains at least a few statements that are nothing but crackpot nonsense.

Indeed. The writer of the paper (that aawahab76 referenced) misunderstands how slower clock rate and time dilation are concurrently compatible by the theory. What he believes a parodox in SR is actually what makes the theory work.

GrayGhost

 

[harrylin]

I only spent a couple of minutes skimming through it, but that was enough to see that it also contains at least a few statements that are nothing but crackpot nonsense. The author even claims that "Relativity’s postulates are incompatible with Lorentz Transformation" and ends the paper with "Unless we understand that we are dealing with desynchronized clocks and unless we have in mind the meaning of the definitions we're using, we're likely to continue to make predictions about the physical world that will lead us to incomprehensible paradoxes." This shows that he doesn't understand special relativity, and that he's naive enough to think that relativity really is incomprehensible.

I now also skimmed through it; evidently the author does not understand the purely operational meaning of the postulates in special relativity. This often happens. And the conclusion is correct of course.