Today Special Relativity dies

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The discussion centers on the implications of Special Relativity (SR) regarding the detection of photons emitted simultaneously from two sources in different reference frames. In Case #1, both the stationary observer and the moving platform agree that the photons are detected simultaneously, making it true. In Case #2, while the stationary observer sees the emissions as simultaneous, the moving observer does not, leading to a false conclusion for the moving frame. Case #3 highlights that the moving observer detects the photons at different times due to their motion towards one emitter, reinforcing the relativity of simultaneity. The conversation emphasizes the importance of clearly defining reference frames to avoid confusion in understanding the outcomes of these scenarios.
  • #271
Doc Al said:
Whose "laws" are those? You're living in the past, man. :smile:

Are you joking? We have libraries of data! All of modern physics is based upon SR. Entire fields of physics would make no sense without it. It's been tested so many times that it's hard to take these threads seriously.
When did you decide that including the observers velocity was not required? Include the observer's velocity and your precious constant speed of light will remain subject to the obvious that the relative velocity of the speed of light is easily measured.

Doc Al's physics is measured in the width of his smirk.
 
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  • #272
Doc Al said:
Still not getting your point. What do you mean "shouldn't change anything"? If you change frames, you have changed the time measurement.

Of course, what I THINK you are struggling with is this: If all we did was change perspectives, then nothing should change right? Well, for that observer (A?) in your diagrams NOTHING HAS CHANGED. It's only us, the outside observers who have changed our perspective and thus our time measurements.

Time measurements ARE a matter of perspective (in a sense). So if you are talking time, then perspective matters. Just like if you are talking about what you see, then it matters where you stand.

Of course if you are thinking: Something's funny here. How can REALITY change if all I'm doing is changing perspective? Ah... now you're beginning to see the light? ( :smile: ) In relativity (and in the real world) time and distance are frame dependent--but there are quantities that are not frame dependent! In some sense those quantities are more "real" that our frame-dependent times and distances. The "real" physical laws governing the world can't be frame dependent, right? Right! That's the entire point of SR. That's why physical laws must be "Lorentz invariant".

If by "picture" you mean those animations, then OF COURSE they are different--they are views from different frames. But note that the physical reality--the fact that the lights meet the train at the same time & place--is still true in both views!


Your changing perspectives is a ruse. You switch views when it would be a physical impossibility to do that in a real physical situation. You are dummer than a fence post if you believe that your precious mathematical models are not subject to limitations. Just because your math says it can be done does not prove it is physically possible. Trains move, stationaary platforms are stationary throughout the course of events. Change you perspective and the physics will follow? Is this the secret of SR?

You people are going to be chewing on Grounded's thesis for quite a spell.

When a moving frame observer determines simultanously emitted photons in a stationary frame were sequentially emitted in the moving frame, then where did the nonemitted photon go, or where was it when the photons were sequentially emitted in the moving frame? You must simply signore the stationary platform as nonexistent and the only reality left for consideration is the one your moving observer perceives?
 
  • #273
Doc Al said:
Right! Light speed is something that is NOT a matter of "perspective". It's an invariant.
Regardless of ME measuring the relative speed of light in all inertial frames will provide just that: A Constant speed of light and an observer moving wrt the photon source velocity. The speed of light is invariant but the measurement of the speed of light is limited only by the imagination of experimental physicists.
 
  • #274
geistkiesel said:
Prove it. Do you understand the request? Prove it? Where is the missing photon?
You are the one claiming to have lost a photon. What did you do with it? And where were the photons before you turned on the light? :smile:
Show from the postulates of SR that where two photons are emitted simultaneously in a stationary frame that a moving frame observer will observe or determine, the photons were emitted sequentially, non-simultaneously, and explain where the photon that was second to appear was wrt the stationary frame, the moving frame the universe?
Again? Do you even bother to read what I've written in all the threads we've been through? (I know you don't understand it, but at least make an effort to read it.) Read through them again. You'll see that I've calculated exactly where everything is according to everyone. I'm not going to do it again, until YOU give it a try.
Are the photons in the stationary frame the same photons in the moving frame?
Not sure what you're asking here. The photons just are; they don't belong to a frame. Instead of photons, we'd be better off thinking of pulses of light (containing many photons). These pulses emanate from the light sources and can be detected in either frame. (Obviously, M' detects different photons than M. But don't get hung up on that detail. Consider them as both viewing the same pulses of light.)
DOc Al why don't you stop your clowing and posturing, it isn't close to physics and it isn't even in the same zip code as funny.
You know nothing about physics, poor geistkiesel.
 
  • #275
If you do that, wouldn't you agree that observers on the train would always measure the proper length of the train to be unchanged and the clocks would still be synched? Meaning: fire off that light in the middle and both clocks would still read the same time when the photons hit. Am I wrong?

Yah... I started considering the situation earlier when Ram considered synching the clocks then accelerating the train. I could quickly see that it was obvious that the answer depends on how you do it, so I wondered just how you would have to do it to keep the clocks synched in their own frame.

Doing all of the analysis in the stationary frame, if the train is accelerated towards the right, then no matter how the train gets acceelrated, if I consider two points that correspond to the same time in the train's frame, the right point has a greater temporal displacement and a lesser spatial displacement than the left point. Thus, if compute the proper time difference for each of the ends, the right end must have experienced more proper time than the left end.


For my example, if we switch to units where c = 1 (for simplicity), we consider the case where the left edge of the train lies along the worldline:

r(tau) = < cosh tau, sinh tau >

(exercise: check that tau is, indeed, the proper time along the worldline)

The velocity is given by

v(tau) = < sinh tau, cosh tau >

Thus, for the observer on the left edge his line of simultaneity corresponding to his proper time a is parallel to

< cosh a, sinh a >

because this is the unit vector orthogonal to v(a). The line is given, parametrically, by:

l(d) = r(a) + d < cosh a, sinh a>
= <cosh a, sinh a> + d <cosh a, sinh a>
= <(d+1) cosh a, (d+1) sinh a>

where d is the proper distance along the line of simultaneity. (aka the distance measured by the observer on the left edge of the train)

Setting d = 1 (corresonding to the train being constant length) and letting a vary gives us the worldline of the right edge:

r(s) = <2 cosh s, 2 sinh s>

A little calculus shows us that s is twice the proper time for the right edge.


In summary, according to the observer on the left edge of the train, the length of the train remains constant, but the clock on the right edge is running at double speed.


On a side note, the class of worldlines:

r(tau) = <k cosh (tau / k), k sinh (tau / k)>

has the property that each of them remain unchanged by any Lorentz boost that fixes the origin; in particular, these (and their translates) are the worldlines of observers that feel a constant acceleration.
 
  • #276
ram1024 said:
if in order to make light constant you need to break other "Reality" laws such as Simultaneity, Absolute time, Absolute space, and True universal rest, then i don't need it.

Your loss.

You know, there is a group of people who refuse to consider breaking the "Reality" law of a true universal direction of up and down, They are called the "Flat Earth Society".

Actually that last one, 'True universal rest", is funny, since it hasn't been considered a "law of Reality" since the time of Galileo.
 
  • #277
Doing all of the analysis in the stationary frame, if the train is accelerated towards the right, then no matter how the train gets acceelrated, if I consider two points that correspond to the same time in the train's frame, the right point has a greater temporal displacement and a lesser spatial displacement than the left point. Thus, if compute the proper time difference for each of the ends, the right end must have experienced more proper time than the left end.

the only reason you would think that because your measure of simultaneity is wholly derived from observation impact.

to make it simple, an acceleration from the right just creates more distance covered in comparison to the non-accelerated train. it's this distance that must be accounted for in determining this "reality" compared to the previous non-accelerated one.

the "point of simultaneity" shifts to the left, the clocks don't lose their synchronization, light speed doesn't change, just you're moving at a different speed toward the light and it is intercepted faster.

no length contraction, no "lost simultaneity", no time dialation.

just a change in relative perspective easily corrected using the proper mathematics.

SR is ridiculous :zzz:
 
  • #278
the only reason you would think that because your measure of simultaneity is wholly derived from observation impact.

No, the reason I think that was because I was applying (Minowski) geometry.
 
  • #279
Actually that last one, 'True universal rest", is funny, since it hasn't been considered a "law of Reality" since the time of Galileo

yet true relative rest DOES exist, we use it daily. something CAN exist completely stationary relative to something else.

the universe as a whole is comprised of every object within it. at any given instant if you averaged the locations of every atom/molecule/lepton/quark/whatever within the universe you would get the universal center. it is a consensus point where everything in the universe takes motion about that axis. anyone with omniscient information would agree with you.

Relative to that location exists universal rests. determined purely on a mathematical basis.
 
  • #280
No, the reason I think that was because I was applying (Minowski) geometry.

but the path you took to your conclusion was towards SR. you had other options. your calculations did not retain simultaneity at the center of the train, so immediately you jumped to the conclusion that simultaneity was at fault.
 
  • #281
geistkiesel said:
SR says, that photon B is emitted before photon A, which means the photons did not exist as a pair for a t > 0. There is no SR postuilates that will surpress the existence of the photons emitted simultaneously in the stationary by virtue of measuring the arrival times on the moving frame. Nor does SR provide for 'gost emitters' that would allow for the delayed emission of photons in the moving frame that have already been emitted. simultabneously in he stationary frame. The mere fact that SR predicts the photons were not emitted simultaneously is proof of the intrinsic error and fault and uselessness of SR.

This would be true if each observer's space wasn't distorted through time (Observer A experiences t=0 BEFORE Observer B, or vice versa!).




As for Case #7, I'll answer AGAIN:
There are 3 possible frames: Picture, Observer, and emitter.

1 - Neither is moving. From any of our 3 frames it takes the photon the same time to reach the observer.
2 - Emitter moving inward. In this case the observer and picture frames are identical. From the picture/observer frame: Light speed is independant of the speed of the emitter so it will take the same time as we observed (1). We'll cover the emitter's perspective later (it is seen in (4))
3 - Same situation as (2) except that the emitter is moving away. The photon still takes the same time as (1) from the observer and picture frames.
4 - Now the observer is moving towards the emitter. Now, this is the EXACT same thing as the emitter's frame in (2). It will take the photon less time to reach the observer because by the time it hits him he has moved closer to the emitter.
5 - Exact same thing as (4) except that this is the emitter's frame in (3).
 
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  • #282
This would be true if each observer's space wasn't distorted through time (Observer A experiences t=0 BEFORE Observer B, or vice versa!).

time is absolute. no one experiences any specific instant of time BEFORE or AFTER anyone else. if you calculate "time" using "light" then of course people receive photons from a source at different "times" depending on where they are when it hits them. light speed is not instantaneous, to measure "time" using something that propagates instead of calculating instantaneous transmission is sheer folly.

think about it this way. do we tell ourselves that light from a star 50 light years away doesn't EXIST until we see it? if this star explodes do we tell everyone "hey today this star exploded". no we do not, we tell everyone 50 years ago this star exploded, we're receiving the evidence of its explosion today.

anyone in that solar system is long dead, they did not die today.
 
  • #283
geistkiesel said:
How can two photons emitted simultaneously in one frame, now turn into photons emitted sequentially when observed in a moving frame?

Geistkiesel.. you just don't listen... ram1024 turned out to be no better than you either.. but I will still try to convince you. Consider, please:


[A_______X_______B] ->
____________________________

A,X,B is the train moving to the right according to the embankement.

X shoots two lasers in opposite directions. The lasers hit the A and B at the same time according to the train. From the embankement's perspective, the lasers hit A and B sequentially, because the train moved to the right. Now which conclusion is real?

To test it, let A and B shoot bullets when they detect the lasers. From the train's perspective, the bullets hit X at the same time, because they were fired at the same time.

From the embankement's perspective, the bullets also hit X at the same time, but they were not fired at the same time because the lasers didn't hit them at the same time, nevertheless the bullets hit X at the same time because X moved according to the embankement.

See, it's just the interpretations that change, the events don't change.

edit: If you tend to prefer the embankement's interpretation over the train's , try to put yourself in X's shoes. Don't look out of the windows. You are in a room. What you consider "at the same time" is when the bullets were fired. You see two bullets fired at the same time and they hit you at the same time.
 
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  • #284
ram1024 said:
time is absolute. no one experiences any specific instant of time BEFORE or AFTER anyone else. if you calculate "time" using "light" then of course people receive photons from a source at different "times" depending on where they are when it hits them. light speed is not instantaneous, to measure "time" using something that propagates instead of calculating instantaneous transmission is sheer folly.

think about it this way. do we tell ourselves that light from a star 50 light years away doesn't EXIST until we see it? if this star explodes do we tell everyone "hey today this star exploded". no we do not, we tell everyone 50 years ago this star exploded, we're receiving the evidence of its explosion today.

anyone in that solar system is long dead, they did not die today.

TIME IS NOT ABSOLUTE. This is one the consequences of relativity. Of course we're going to disagree on relativity if we disagree on this point. A second for me can be two seconds for you. A second for my leg can be half a second for my arm. Everything is relative!

I refer you to that nice picture I posted earlier.
 
  • #285
wespe said:
Geistkiesel.. you just don't listen... ram1024 turned out to be no better than you either.. but I will still try to convince you. Consider, please:


[A_______X_______B] ->
____________________________

A,X,B is the train moving to the right according to the embankement.

X shoots two lasers in opposite directions. The lasers hit the A and B at the same time according to the train. From the embankement's perspective, the lasers hit A and B sequentially, because the train moved to the right. Now which conclusion is real?

To test it, let A and B shoot bullets when they detect the lasers. From the train's perspective, the bullets hit X at the same time, because they were fired at the same time.

From the embankement's perspective, the bullets also hit X at the same time, but they were not fired at the same time because the lasers didn't hit them at the same time, nevertheless the bullets hit X at the same time because X moved according to the embankement.

See, it's just the interpretations that change, the events don't change.

If you don't mind I'd just like to work that out.

(Train frame)
c=lightspeed
v = bulletspeed
w = trainspeed
d = distance(X, A), as well as distance(X, B)
time for bullet #1 to intersect: c/d + v/d
#2: c/d + v/d

(Stationary frame) (ooo oxymoron)
light goes towards right mirror
'(v+w) because the bullet appears to go faster for the observer
#1:(c-w)/d + (v+w)/d
towards left mirror
'(v-w) because now the train is "working against" the bullet.
#2:(c+w)/d + (v-w)/d

Now we check for equality
#1:
(c-w)/d + (v+w)/d = c/d+v/d
(c-w+v+w)/d = (c+v)/d
(c+v)/d = (c+v)/d
#2:
(c+w)/d + (v-w)/d = c/d+v/d
(c+w+v-w)/d = (c+v)/d
(c+v)/d = (c+v)/d

Well, that proves that.
 
  • #286
what is "that proves that" ?

what were you trying to prove?
 
  • #287
Doc Al said:
You are the one claiming to have lost a photon. What did you do with it? And where were the photons before you turned on the light? :smile:

Again? Do you even bother to read what I've written in all the threads we've been through? (I know you don't understand it, but at least make an effort to read it.) Read through them again. You'll see that I've calculated exactly where everything is according to everyone. I'm not going to do it again, until YOU give it a try.
Not much physics here is there? SR predicts that the photons will be emitted sequentially in the moving frame. THis measn that one photon cannot exist for that period of time that the B photon preeced3ed the A photon being emitted. But the stationary frame had emitted trwo photons simum,tabneously. If SR is tweaking space and time where did the lost photon go. It is a serious question Doc Al, you can't avoid it with cycnicism forever.


Doc al said:
Not sure what you're asking here. The photons just are; they don't belong to a frame. Instead of photons, we'd be better off thinking of pulses of light (containing many photons). These pulses emanate from the light sources and can be detected in either frame. (Obviously, M' detects different photons than M. But don't get hung up on that detail. Consider them as both viewing the same pulses of light.)

You know nothing about physics, poor geistkiesel.

OK think about pulses of light. When the moving observer determines that the B photon was emitted before the A photon this has a physical meaning. It says that the A photon was suppressed from the emission process, according to the moving frame observers, but the stationary frame emitted photons simultaneously. SR is dead.
 
  • #288
ram1024 said:
if in order to make light constant you need to break other "Reality" laws such as Simultaneity, Absolute time, Absolute space, and True universal rest, then i don't need it.

show me the data. you guys messed up your calculations somewhere down the line
You are 100% on Ram1024. When SR says moving observers see simultaneous emitted photons in the stationary frame turn into sequential emitted photons they are saying that for sime t > 0 thee was only one photon around. Where was the other photon that followed the first photon?

Ram1024 so much will be cleared fro you when you go through Grounded's papers. You are a foll to pass this up.
 
  • #289
Janus said:
Your loss.

You know, there is a group of people who refuse to consider breaking the "Reality" law of a true universal direction of up and down, They are called the "Flat Earth Society".

Actually that last one, 'True universal rest", is funny, since it hasn't been considered a "law of Reality" since the time of Galileo.

So when are you going to include the observer in the motion when measuring the speed of light? If yopu don't you will always get C. You will always get an error. See the Grounded papers.

OK smart guy, measure the flat of the planet on the surface,. You will never be able to measure round. The ships coming to port over the horizon are measurements at a distance. Within limits the planet is measured flat man. Get used to it.
 
  • #290
Hurkyl said:
Yah... I started considering the situation earlier when Ram considered synching the clocks then accelerating the train. I could quickly see that it was obvious that the answer depends on how you do it, so I wondered just how you would have to do it to keep the clocks synched in their own frame.

Doing all of the analysis in the stationary frame, if the train is accelerated towards the right, then no matter how the train gets acceelrated, if I consider two points that correspond to the same time in the train's frame, the right point has a greater temporal displacement and a lesser spatial displacement than the left point. Thus, if compute the proper time difference for each of the ends, the right end must have experienced more proper time than the left end.


For my example, if we switch to units where c = 1 (for simplicity), we consider the case where the left edge of the train lies along the worldline:

r(tau) = < cosh tau, sinh tau >

(exercise: check that tau is, indeed, the proper time along the worldline)

The velocity is given by

v(tau) = < sinh tau, cosh tau >

Thus, for the observer on the left edge his line of simultaneity corresponding to his proper time a is parallel to

< cosh a, sinh a >

because this is the unit vector orthogonal to v(a). The line is given, parametrically, by:

l(d) = r(a) + d < cosh a, sinh a>
= <cosh a, sinh a> + d <cosh a, sinh a>
= <(d+1) cosh a, (d+1) sinh a>

where d is the proper distance along the line of simultaneity. (aka the distance measured by the observer on the left edge of the train)

Setting d = 1 (corresonding to the train being constant length) and letting a vary gives us the worldline of the right edge:

r(s) = <2 cosh s, 2 sinh s>

A little calculus shows us that s is twice the proper time for the right edge.


In summary, according to the observer on the left edge of the train, the length of the train remains constant, but the clock on the right edge is running at double speed.


On a side note, the class of worldlines:

r(tau) = <k cosh (tau / k), k sinh (tau / k)>

has the property that each of them remain unchanged by any Lorentz boost that fixes the origin; in particular, these (and their translates) are the worldlines of observers that feel a constant acceleration.
Hurkyl, here is a calculation with an order of magnitude of simplicity less than your own there. In the moving train experiment where the observer is at the stationary midpoint fo the photon sources when the pphotons are emitted in the stationaryframe we have a contradiciton in SR theory.

AS the observer passes from the midpoint she knows her velocity hence she is able to maintain a motorizede detector at the original midpoint. Consider this device mving in the obposite direciton from the train in the train frame and moving at velocity equals 0 wrt stationary frame. When the photons arrive first from B in the front then from A in from the back we have left out an important measurement.

Keeping a continuous watch at the midpoint the constant midpoint observer will detect the photons arriving at the stationary frame. And as the photons arrive simultaneously the moving frame observer measures the photons arriving simultaneously just like the observer would have detected the photons had she not been moving. SR is a game of contrivances.

See how simple this is. The moving observer maintains a watch at the midpioint of A and B which she can do from her moving frame. She must then see the simultanoeus arrival of the photons from her frame.
 
  • #291
geistkiesel said:
So when are you going to include the observer in the motion when measuring the speed of light?

There is no need to "include the observer", because the observer is at rest in his own frame. All the observer has to do is record the time and place of the emission, and the time and place of detection. Take the ratio of &Delta;x and &Delta;t, and you get c.

If yopu don't you will always get C. You will always get an error.

There is no error. The rate at which a photon approaches me is the distance I measure it to cover divided by the time it took to do it.

See the Grounded papers.

Janus already knows Galilean relativity.

OK smart guy, measure the flat of the planet on the surface,. You will never be able to measure round. The ships coming to port over the horizon are measurements at a distance. Within limits the planet is measured flat man. Get used to it.[/QUOTE]
 
  • #292
Doc Al said:
I wouldn't want to take anything away from Hurkyl's professional rep, but you must admit that you are pretty easy to confuse. :smile:
This is becasue I make an effort to take you seriously, but you aren't in this for the ohysics, you are in this for the religious conotations.
 
  • #293
ram1024 said:
Case #7
Code:
                     [u](o)                                        <-)|[/u]
                     [u](o)                                        <-)|[/u]
                     [u](o)                                        <-)|[/u]
                     [u](o)                                        <-)|[/u]

in this setup, we have but one emitter and one observer. keeping it simple-like. In all cases the emitter is going to emit a pulse of light on the first "frame" of the setup. assume uniform motion (no acceleration).

step1: emitter stays the same place towards the observer.

Code:
                     [u](o)                                        <-)|[/u]
                     [u](o)                                     <-)|[/u]
                     [u](o)                                  <-)|[/u]
                     [u](o)                               <-)|[/u]

emitter moves towards the observer.

Code:
                     [u](o)                                        <-)|[/u]
                     [u](o)                                           <-)|[/u]
                     [u](o)                                              <-)|[/u]
                     [u](o)                                                 <-)|[/u]

emitter moves away from observer.

This is simply a demonstration of what you're saying that light doesn't care what its source does, right? In all 3 cases light would reach the observer at the same time if the first "frame" were synchronized.

now we're going to do what you guys do to things...

Code:
                     [u](o)                                        <-)|[/u]
                        [u](o)                                     <-)|[/u]
                           [u](o)                                  <-)|[/u]
                              [u](o)                               <-)|[/u]

Code:
                     [u](o)                                        <-)|[/u]
                  [u](o)                                           <-)|[/u]
               [u](o)                                              <-)|[/u]
            [u](o)                                                 <-)|[/u]

we're going to take the same set ups from above and simply CHANGE the relative motion so that the emitters are stationary and the observer is the one that's moving. this shouldn't change ANYTHING as far as you guys see it right? these cases should be EXACTLY the same as the ones above, we just changed perspective...

Discuss.

Ram1024 simply add the motions of the observer to the speed of lite and the time dilations disappear,.
 
  • #294
ram1024 said:
if in order to make light constant you need to break other "Reality" laws such as Simultaneity, Absolute time, Absolute space, and True universal rest, then i don't need it.

I see you haven't learned a thing from our discourse last weekend. You still cling to your "rational" view of the world, no matter how untenable it is. You still think that what sounds reasonable to you must be right. You still think that everyday, common-sense notions must be absolute truths, despite the fact that our everyday, common-sense notions are shaped by a very limited set of circumstances (such as "normal" speeds being much, much less than that of light).

show me the data.

I will gather my resources together and post them, but there is no need for you to wait for that. Get up out of your armchair, and look for yourself. You can start by tracking down the following article:

Alvager F.J.M. Farley, J. Kjellman and I Wallin, Physics Letters 12, 260 (1964)

That group measured the speed of light from fast-moving sources, and it comes out to be 'c'. Experimental confirmation doesn't get more direct than that.

you guys messed up your calculations somewhere down the line

Do you really think that those calculations haven't been checked and re-checked? Do you really think that some amateur internet bozo has found something that full-time professional physicists have not? Give me a break. :rolleyes:
 
  • #295
If SR is tweaking space and time where did the lost photon go.

It hasn't been created yet.



From these discussions, I think I'm beginning to understand just how big the paradigm shift from "space parametrized by time" to "space-time" was.
 
  • #296
Tom Mattson said:
I see you haven't learned a thing from our discourse last weekend. You still cling to your "rational" view of the world, no matter how untenable it is. You still think that what sounds reasonable to you must be right. You still think that everyday, common-sense notions must be absolute truths, despite the fact that our everyday, common-sense notions are shaped by a very limited set of circumstances (such as "normal" speeds being much, much less than that of light).



I will gather my resources together and post them, but there is no need for you to wait for that. Get up out of your armchair, and look for yourself. You can start by tracking down the following article:

Alvager F.J.M. Farley, J. Kjellman and I Wallin, Physics Letters 12, 260 (1964)

That group measured the speed of light from fast-moving sources, and it comes out to be 'c'. Experimental confirmation doesn't get more direct than that.



Do you really think that those calculations haven't been checked and re-checked? Do you really think that some amateur internet bozo has found something that full-time professional physicists have not? Give me a break. :rolleyes:

OK Tom check this calculation. When the observer on the train is at the midpoint of the photon sources in the stationary frame she 0 her clock and notes her constant velocty. She has installed a motorized device that maintains the posiotion of the observer at t0 = 0 = t'0. This motorized detector maintains a constant watch on the detector set to measure thearrival of the photons from A and B. The deivice is moving at -v wrt the observer. AT t'1 she measure the photon from B and at t'2 the photons arrived simultaneously in the stationary frame at the midpoint.. AT t'1 the photon has traveled t'1c in the moving frame. At t'3 she measures the photon from A. She is physically on the train where she was when passing through the midpoint of A and B. As she analyzes later, the photons arriving at the midpoint at t'2 was unexpected as SR had predicted the photons would arrive sequentially. Of course the SR is referring to the position of the original observer who has moved..

Continuing on in this line she may assume reasonably that the photons were the photons emitted in her frame. That the photons met simultaneously at the midpoint of A and B she may assume the A photon was located at a distance -t'1v when the B photon was detected. Therefore the A photon must move a distance c(t'3 - t'1) which is equal to t'1v + t'1v + (t'3 - t'1)v. Collecting t'3 on the left we arrive at t'3 = t'1( c + v)/(c - v) . Using v= 10^-5(c) and setting c = 1, we get t'3 = t'1(1.00001)/.99999 = 1.00002t'1.
Now we substitute c(1.00002 - 1)t'1 = t'1(.00001)c = 2t'1(10^-5 ) + t'1(10^-5). Now as c = 3 10^-5, we have c10^-5 = 3x (10^-5) which is the same distance measured and traveled by the photon. The measurenment of the simultaneous arrival of the photons at the original midpoint could very well have been accomplished by a rigid series of detectors movong with the frame. These will react when the photons arrived. One detector would simultaneously detect the arrival of the photons at the original location of the midpoint of A and B in the moving frame.

Grounded's velocity addition device seems to work very niclely. What does SR predict under the present conditions? v = 10^-5 c, t'1 = 1 and c = 1.

A simple addition of the observers velocity clears up a lot of SR tweaking doesn't it?

You haven't indicated any progress in understanding Grounded's theses.
 
  • #297
geistkiesel said:
Grounded's velocity addition device seems to work very niclely. What does SR predict under the present conditions? v = 10^-5 c, t'1 = 1 and c = 1.

A simple addition of the observers velocity clears up a lot of SR tweaking doesn't it?

What do you think this pointless exercise proves? You have simply declared your prediction to be right, without making any reference to the real, physical world.

You haven't indicated any progress in understanding Grounded's theses.

Grounded doesn't have "theses". The theory he is espousing is nothing other than Galilean relativity, and I understand it perfectly well. You, on the other hand, have not indicated any progress in differentiating between imaginary thought experiments and real experiments. The condition of confusing the imaginary for the real has a name. It's called "psychosis".

I am thoroughly sick of your thought experiments, and I am finished wasting my time on them. I agree with ram's comments that we aren't referring to real experiments as we should be.
 
  • #298
Hurkyl said:
It hasn't been created yet.



From these discussions, I think I'm beginning to understand just how big the paradigm shift from "space parametrized by time" to "space-time" was.

Hurkyl - put a motorized detector on the moving train to maintain a constant position directly next to the midpoint of the A and B detectors. Let the observer meet the photons later at t'1 and t'3. We use t'2 to be the instant the photons arrived simultaneously in the stationary platform, all witnessed by the fixed 'moving' observer at M. When analyzing the moving observer can determine the effect on the simultanous nature of emitted photons as a function of the observers motion. The motion of the observer changes, not the laws of physics, but the experimental conditions. Where M amd M' were once colocated, there can be no serious question that the photons will arrive at M' at a different time because it has moved. To call this a loss of simultaneity is foolish especially when the moving observer can easily determine the simultaneous nature of the photons without regard to the intrinsic errors in measuring the speed of light without using the velocity of the observer as a factor. Without the added velocities one is forced into the silly time dilation and mass shrinking scenario.

The thing about the stationary moving observer is that the observations are available for analysis in th emoving frame.

Hurkyl this isn't the insanity of one determined to lead a rational life where observations are what they appear to be. This is a rational analysis that just so happens to contradict SR.

Finally, Hurkyl, if the photons were emitted sequentially this means that one of the photons would have had their emission suppressed. This in light of the simultaneous emission of photons in the stationary frame leaves an insurmountable barrier doesn't ir?
 
  • #299
Do you understand the concept of a distance versus time plot?

Does this look like a drawing of the experiment you describe?

<br /> \begin{picture}(300,240)(0,0)<br /> \put(0,240){\line(1,-3){70}}<br /> \put(70,20){A}<br /> \put(100,240){\line(0,-1){210}}<br /> \put(100,20){M&#039;}<br /> \put(100,240){\line(1,-3){70}}<br /> \put(170,20){M}<br /> \put(200,240){\line(1,-3){70}}<br /> \put(270,20){B}<br /> <br /> \put(0,240){\line(1,0){270}}<br /> \put(280,240){x}<br /> <br /> \put(0,240){\line(0,-1){210}}<br /> \put(0,20){t}<br /> <br /> \put(0,240){\line(1,-1){180}}<br /> \put(200,240){\line(-1,-1){125}}<br /> \end{picture}<br />
 
Last edited:
  • #300
Tom Mattson said:
What do you think this pointless exercise proves? You have simply declared your prediction to be right, without making any reference to the real, physical world.



Grounded doesn't have "theses". The theory he is espousing is nothing other than Galilean relativity, and I understand it perfectly well. You, on the other hand, have not indicated any progress in differentiating between imaginary thought experiments and real experiments. The condition of confusing the imaginary for the real has a name. It's called "psychosis".

I am thoroughly sick of your thought experiments, and I am finished wasting my time on them. I agree with ram's comments that we aren't referring to real experiments as we should be.

Are you telling me, or trying to tell me that SR isn't an imaginary discipline? And where do you get Psychosis? I know we refer to each other as crazy, but I would like to know where you arrive at psychosis? Just because I or others disagree with you? You read below and tell me thios is the ranting of a mad man as witnessed by his lack of reasoning in his analytic posture.

Where have you heard Grounded's theses? Who in your career has said we must add the velocities of the observer into the calculations? And who contiued along in the line taken by grounded in calculating frequency abnd wave length? Who said this and where was she dismemebred?

If you understand Grounded very well then why do you have to resort to some vague reference to the Galilean nature of his theses? Your mathematical description a hwile back was impressive, as I noted. Clear, straightforward, careful use of proper parameters in the equatons, all of that which is expected of one who knows his theory, which you obviously do. Tom how many times have you pondered the limitations of mathematics to adequately describe physical activity? Just because the math says you can do it doesn't mean it is physically proper. A train station is stationaary and a train is mobile, moving. To say you can mathematically swap reference frames while being a physical impossibility, then why even broach the matter in analysis? Let me guess because you get the right answer doing it that way?

You mention real experiments and I look them up and see they are flawed with the same erronoeus reasoning that you manifest. It seems you are getting tired Tom,. It must be a chore being the smartest one in the room all the time, with no reasonbale relief in sight.

It would do you well tom to get yourself into Grounded's shoes. Also, you might tell me where the photon that follows the first emitted photon in the moving frame is hiding when the first is emitted,. You do rememebr that the photons were emitted simultaneously in the stationary frame don't you?

The words 'galilean reference frame' is your latest mantra Tom.
 

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