SR Simultaneous Lines Drawn in the Sand

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The discussion centers on Einstein's thought experiment regarding simultaneity in special relativity, specifically the scenario involving two light sources, A and B, and an observer in a moving frame. It is established that while stationary observers perceive the emissions from A and B as simultaneous, the moving observer O' does not, due to their motion towards B and away from A, resulting in a time difference in detection. Participants debate the implications of simultaneity, emphasizing that the timing of light detection is frame-dependent and not solely based on the observer's position at the moment of emission. The conversation highlights the fundamental principle that the speed of light is constant across all frames, leading to different conclusions about simultaneity based on relative motion. Ultimately, the discussion reaffirms that events simultaneous in one frame may not be so in another, underscoring the complexities of time perception in relativity.
  • #121
Geistkiesel: here is your experiment drawn as a diagram:

Code: 
0        0        0
*\       *       /*
* \      *      / *
AZ \     MN    /  BY
AZ  \    MN   /   BY
AZ   \   MN  /    BY
A Z   \  M N/     B Y
A Z    \ M *      B Y
A Z     \M/N      B Y
A  Z     *  N     B  Y
A  Z     M\ N     B  Y
A  Z     M \N     B  Y
A   Z    M  \N    B   Y
A   Z    M   *    B   Y





  Z A    NM     0
  ZA     NM    /*
  ZA     0    / *
  ZA     *   / BY
  0      *  /  BY
  *\    MN /   BY
  * \   MN/   B Y
 AZ  \  M*    B Y
 AZ   \M/N    B Y
 AZ    * N   B  Y
A Z    M\N   B  Y
A Z   M  *   B  Y

Legend:
A, M, B: your A, M, B
Z, N, Y: Your A', M', B'
0: A point where a clock read 0
\, /: photons
*: Multiple things at this point (such as two clocks, or a clock and a photon)

The first diagram is the stationary reference frame. The second diagram is the moving reference frame. Space runs from left to right, and time increases as you go downward.

The first diagram was taken directly from your experimental setup. I placed M and N midway between A/Z and B/Y, and simply drew out the time evolution of the system.

To draw the second diagram, I started with the unambiguous fact that both photons meet precisely when they each meet M. I drew the time evolution backwards, and used the fact that N is midway between Z and Y when M meets N to place where Z and Y should be. I then applied the fact that Z meets A and are both set to zero when the left photon is emitted to finish off the left side of the diagram, and similarly for Y and B. I did, however, have to estimate how N lies relative to M. Any other such choice yields a similar diagram.


Your mistake, as everyone is trying to tell you, is made clear from the diagram. In the moving frame, the clocks are not synchronized; you can see that they are all zero at different times. We see that SR can handle this scenario perfectly well, as long as you don't start with the assumption that synchronization in one frame = synchronization in all frames.




(NOTE: In the second drawing, to keep the diagram small, the lexical distance between A and M is 6 and one-third characters)
 
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  • #122
baffledMatt said:
I still don't see exactly what you mean by this. Could you perhaps give me the dumbed down version of how exactly this is done? It's no good you saying 'using the same physics' since we evidently don't agree on exactly what the physics is!

baffledMatt, whatever the physics used to measure the midpoint in the stationary frame is used in the moving frame.
You can pick you own method.

measure the midpoint of M using some eflected laser scheme relying on time of flight of the beam photons. Ditto for M'.The M' only allows us to guarantee that the number of an an exposed ps-strip near A will have the same number of the exposed ps-strp at B. The scientists calculate shrinking from a known velocity acihieved through repeated acceleration schemes. Approaching A and B from two directions and taking phtographs of the AA' positions, the moving frame can assure itself that wherever the photon expsoes the ps-strip its eflected number at the other end of the frame will be identically exposed. Observers eye-to-eye 1 wave length apart when the photons are emitted must see the same event. If you want to slow down the brain functions in the moving frame ok, by the photons aren't going to play any special games with the moving frame just because it is there. So if brain slowing is the physical ef fect of nonsimultaneity I can understand that.



baffledMatt said:
I can see why you might think that - I remember having exactly these sorts of problems with SR. The way I would always go about solving these problems though was to sit down and just calculate the thing. To illustrate:
Let's make some definitions:
x : space coordinate in 'stationary' frame. x = 0 is the midpoint between A and B, which are located at x = -L and x = L respectively.

v : velocity of the moving observer relative to the stationary observer.

Ok, so now I will calculate what the 'stationary' observer sees. Note I am not going to use any SR as such. We first calculate the location of the point where the 'moving' observer and the light from A coincide. This happens at a time t_A after the light is emitted from A and the point where they meet we denote d_A. By equating the distance the light moves in this time to the distance the moving observer moves we have:

vt_A = d_A
ct_A = d_A + L
so
\frac{v}{c}(L + d_A) = d_A
and
d_A = \frac{\frac{v}{c}L}{(1-\frac{v}{c})}

Similarly, we can derive d_B which is the point where the moving observer meets the light from B
vt_B = d_B
ct_B = (L-d_B)
so
\frac{v}{c}(L-d_B) = d_B
and again
d_B = \frac{\frac{v}{c}L}{(1+\frac{v}{c})}

Evidently, d_A \neq d_B so the photons do not hit the moving observer at the same time/place.



Ok, now repeat the calculation above, but for the moving observer. The only SR result I want you to use is that each observer must observe the same value for the speed of light. If you do this you should see that you need things like time dilation and lack of simultaneity to resolve the observations.

Matt

The problems you used to have were eleiminated using SR. Without SR there is no paradoxes, none. It osunds like a religious convert, really. "My life turned around when I found Godot", or something similar.
Do you want to argue all the experimetnal results proving the postuilates, while I show all the contradictions, exceptions, flaws. You show me my flaws I show you yours. This really isn't a physics discussion, all that much is it?

I know its my fault.

You needn't show this to me I believe it will work as you say. My doing the calculations will not change anything. There is still the matter of the ps-strips being exposed when the photons are emitted. There is no paradox until SR is applied. then we have the big sticker. Mere presence of observers grossly affecting a physical event, by operation of postulate. Is there any language you can use other than that demanded by Sr that can explain the physical manifestation arising from a simultaneous event by operation of the presence eof observers. Can you do this?

If there are no observers on a moving frame observing is there a nonsimultaneous event occurring? I am not asking a question with any implied determinism demanded in the answer, but the inversion of reason and the operation of physical law don't work in SR, at lexst not heer. I discard it.
 
  • #123
Hurkyl said:
Geistkiesel: here is your experiment drawn as a diagram:

Code: 
0        0        0
*\       *       /*
* \      *      / *
AZ \     MN    /  BY
AZ  \    MN   /   BY
AZ   \   MN  /    BY
A Z   \  M N/     B Y
A Z    \ M *      B Y
A Z     \M/N      B Y
A  Z     *  N     B  Y
A  Z     M\ N     B  Y
A  Z     M \N     B  Y
A   Z    M  \N    B   Y
A   Z    M   *    B   Y





  Z A    NM     0
  ZA     NM    /*
  ZA     0    / *
  ZA     *   / BY
  0      *  /  BY
  *\    MN /   BY
  * \   MN/   B Y
 AZ  \  M*    B Y
 AZ   \M/N    B Y
 AZ    * N   B  Y
A Z    M\N   B  Y
A Z   M  *   B  Y

Legend:
A, M, B: your A, M, B
Z, N, Y: Your A', M', B'
0: A point where a clock read 0
\, /: photons
*: Multiple things at this point (such as two clocks, or a clock and a photon)

The first diagram is the stationary reference frame. The second diagram is the moving reference frame. Space runs from left to right, and time increases as you go downward.

The first diagram was taken directly from your experimental setup. I placed M and N midway between A/Z and B/Y, and simply drew out the time evolution of the system.

To draw the second diagram, I started with the unambiguous fact that both photons meet precisely when they each meet M. I drew the time evolution backwards, and used the fact that N is midway between Z and Y when M meets N to place where Z and Y should be. I then applied the fact that Z meets A and are both set to zero when the left photon is emitted to finish off the left side of the diagram, and similarly for Y and B. I did, however, have to estimate how N lies relative to M. Any other such choice yields a similar diagram.


Your mistake, as everyone is trying to tell you, is made clear from the diagram. In the moving frame, the clocks are not synchronized; you can see that they are all zero at different times. We see that SR can handle this scenario perfectly well, as long as you don't start with the assumption that synchronization in one frame = synchronization in all frames.




(NOTE: In the second drawing, to keep the diagram small, the lexical distance between A and M is 6 and one-third characters)

You are mistating the thread hypothetical. I have never said the frames were sycnchronized between them. I have stated the opposite. Your statement is a total falsehood, conscious or otherwiise. Your diagram , is a perversion on the original. You are trying to sabotage a thread for your own aggrandizment. Do you get a bonus, or is theprize recognition? Your just another phony, and a liar. You made it up Hurkyl

Take your lexical distances and shove them some place that will do you some good. But all I can predict now, until the last star fades from the sky is that Hurkyl is just another common usless liar and is not to be trusted, ever. I am not answering your crap anymore. Our conversation is over.
 
  • #124
Why don't you cut with the personal attacks and draw out a diagram of your own? Or is intentional obfuscation your goal?
 
  • #125
geistkiesel said:
The problems you used to have were eleiminated using SR. Without SR there is no paradoxes, none. It osunds like a religious convert, really. "My life turned around when I found Godot", or something similar.
Do you want to argue all the experimetnal results proving the postuilates, while I show all the contradictions, exceptions, flaws. You show me my flaws I show you yours. This really isn't a physics discussion, all that much is it?

The difference between this and religion is that SR is completely logical. You start from the principle of relativity and everything else is deduced from this. So the only thing I got converted to was the principle of relativity - if you want to call that religion then be my guest.

You have not shown us any flaws in SR, only flaws in your interpretation of SR.

There is still the matter of the ps-strips being exposed when the photons are emitted. There is no paradox until SR is applied.

There is no paradox, period! Only gross misunderstandings.

then we have the big sticker. Mere presence of observers grossly affecting a physical event, by operation of postulate. Is there any language you can use other than that demanded by Sr that can explain the physical manifestation arising from a simultaneous event by operation of the presence eof observers. Can you do this?

This depends on your point of view. I do not consider there to be any physical relevance to two things being simultaneous, so the results of SR do not bother me.

Why do you think there is any significance to things being simultaneous? If two events happen at different locations and the same time then there is no physical way the two events are connected - they are outside of each others light cones. So each event has no idea that it is occurring 'at the same time' as another event. Why do you attach so much significance to things which cannot be causally related?

Matt
 
  • #126
geistkiesel said:
You made it up Hurkyl

Take your lexical distances and shove them some place that will do you some good. But all I can predict now, until the last star fades from the sky is that Hurkyl is just another common usless liar and is not to be trusted, ever. I am not answering your crap anymore. Our conversation is over.

Riiight. All this coming from a guy trying to convince us that his own theory - which is devoid of calculations or even physics for that matter - proves that SR is wrong.

Don't you think it would be better to try and show us exactly why you think Hurkyl is lying, rather than all this immature name calling?

Matt
 
  • #127
baffledMatt said:
The is no physics in your link! You don't make any calculations so how can I judge it? Then I click on the link to the so-called analysis and there is just a tiny little calculation which has already assumed your point is correct.

I have tried to show you calculations in a way to help you understand how the whole thing works but you reply with:


I mean, do you want to be helped? Sorry, but physicists are not philosophers. You have to do calculations to really understand things.



Why is this a paradox? where is the magic? You are the one trying to bring in fairies by demanding something 'is' or 'is not' simultaneous.



This is the crucial point. Imagine I am observing someone moving relative to me. I can watch everything he does, see him measure things with his own measuring devises etc. Now, there must be no discrepancy between the measurements he makes and the ones I observe him to make. It's just that the explanation to why he got the result he did will differ between our frames (I'll say that his measuring stick shrunk wheras he will say that the events were not simultaneous.)

As another example, try this one. Imagine we both have clocks, we know that when they are in the same inertial frame that they tick at exactly the same rate - and they stay like that (they are very good clocks!). Now, you are moving at a velocity v relative to me and at the moment you pass me (ie our x coordinates coincide) we synchronize the clocks - make sure they are telling exactly the same time at that point in time.

Now, you are moving relative to me and so I observe your clock as ticking slightly slower. However, since I am also (relativistically speaking) moving relative to you, you shall also observe my clock as going slower than yours. We each observe each other's clock as going slower. But this is fine, there is no disagreement as such because all I can say is "I observe your clock as slow", I don't know what you might be observing.

Ok, now imagine that you break your clock at time T by your clock. This is an event we must both agree on, when your clock had the small hand pointing at T you broke it. Now, I observe your clock as ticking slower than mine so my clock reads \gamma T at the point when you break it. In fact, as soon as I see your clock stop i stop mine also so we must again both agree on this measurement, we both see \gamma T on my clock.

However, now for the 'paradox'. In your frame you were observing my clock as running slower than yours! So you might reason that my clock ought to read T / \gamma. But it doesn't, it reads \gamma T and we can both see this.

Resolve the paradox.



But then your establishment of simultaneity will only be accurate to this same error. You say that you will use an excess of strips so this error will in fact be pretty huge. Thus the results will prove nothing.



But how are you performing these measurements?! You are assuming that these are things you can simply measure and will give you your expected result QED. What you are forgetting is that SR is all about measurement! It's a fact that different observers measure different things. But they all observe the same events.

Do you see the subtlety? "The distance between the sources is 2L" is a measurement which observers can disagree on, as is "the emission was simultaneous". But "I measured the distance to be 2L" is an event. All observers will see me make this measurement and observe me getting the result I did. It is only the events which we all agree on.



Yes it does. The frame is trying to measure events which occur in a different frame. I would say that therefore this frame must know a lot about the stationary observer.

Matt


why all the talk about clocks we aren' using them? . If the moving frame has a physical entity located a wave length from a stationary entity and these entities are identical ps_strips and a photon is enmitted exactly between them exposing the ls-strips and the same event is occurring on the other end of the frames, the distance betwene the exposed ls-strips is identical at the instant the photons were emitted, lorentz terms notwithstanding.. The exposure, a fraction of a mico second is identically located, like mirror images of each other other. Your SR theory that describe other than this is bogus. Mathematical chicken scratches on a piecxe of paper does not substyitue for physical law and reason. I trust you will always go in peace with your theory.
I realize I have my own perceptions, biases and a personal fault or two, but I don't swlallow SR: it is poison for the mind, the scientific equivalent of fascism.

Explain to me Doc Al and Hurkyl flat out lying and double talking, sonfusin. attemopting to get me of on some wild goose chase. Thee men are your colleagues. I don't fault you for your fdifferences, in fact i don't fault you. You are, to be sure instinctively SR, but I haven't detected the corruption seen in the other two mentioned.

These are "mentors" . I have only seen such peversion and dishnesty in the politics in thios country. I wonder whio is pulling the chain around their necks?

Don't try this at home children, please don't try this at home.

Some say we humans are free thinkers, free to choose our own destiny. Those two mentioned chose the way they think act and work, and corrupt, always to corrupt.
Chroot, pulled a post of mine cruitical to some yoyo named carp or crap. Hedidn't think the post was scientific enough. Jesus christ, Now I cannot edit my own profile or dio any thing except woprk in thi porum. No problem, I just don't appreciate being handkled by a jerk with such insensitivity. The man is arbitary and snot nosed brat.
 
  • #128
russ_watters said:
Why don't you cut with the personal attacks and draw out a diagram of your own? Or is intentional obfuscation your goal?
See the first post in the thread. I am not making personal attacks I am reposing obsevations.

Whats the matter,you don't like my threads?
 
  • #129
geistkiesel said:
If the moving frame has a physical entity located a wave length from a stationary entity and these entities[...]

All the time you are assuming that there are all these physical entities which 'have length X' or 'are at time Y'. How do you know this? How do you know that the distance between A and B is 2L? You measure it of course. But hang on, now you haven't actually determined what this entitie's 'true length' is, you have made a measurement - there is no way you can talk about the 'true length' because there is no measurement free way of determining it. Then what SR tells us is how these measurements will differ between intertial frames.

are identical ps_strips and a photon is enmitted exactly between them exposing the ls-strips and the same event is occurring on the other end of the frames, the distance betwene the exposed ls-strips is identical at the instant the photons were emitted, lorentz terms notwithstanding.. The exposure, a fraction of a mico second is identically located, like mirror images of each other other. Your SR theory that describe other than this is bogus.

You still think that you are determining some true 'real' property using this measurement. What SR tries to tell us is that the only quantities which do in fact have a 'true' property are the invariant ones (such as rest mass).

Until you think very very carefully about the way you are making your measurements you will never understand this.

Mathematical chicken scratches on a piecxe of paper does not substyitue for physical law and reason.

Excuse me, are you a physicist or a philosopher? If you want to talk this way then please move your discussion to the philosophy section of the forum. I'm afraid that mathematics is the only way we know of to build a coherent and consistent model of the world around us.

Your suggestion of using 'physical law and reason' instead of hard mathematics is exactly the kind of thinking that gave us Ptolemy. They reasoned that perfect circles were 'physical law' despite what the mathematics was telling them. Do you really want us to go back to that way of reasoning?

Matt
 
  • #130
last chance

geistkiesel said:
Explain to me Doc Al and Hurkyl flat out lying and double talking, sonfusin. attemopting to get me of on some wild goose chase. Thee men are your colleagues. I don't fault you for your fdifferences, in fact i don't fault you. You are, to be sure instinctively SR, but I haven't detected the corruption seen in the other two mentioned.
Do you even know what the word "lying" means? It means intentionally saying something that isn't true. Can you point to even one post in which Hurkyl or I said something that wasn't true? Never mind intentionally.
These are "mentors" . I have only seen such peversion and dishnesty in the politics in thios country. I wonder whio is pulling the chain around their necks?
You make wild assertions, and when they are questioned all you can do is sputter and fume. In lieu of reason and argument, you make personal attacks. You bring nothing substantive to the table, geistkiestel.
Chroot, pulled a post of mine cruitical to some yoyo named carp or crap. Hedidn't think the post was scientific enough. Jesus christ, Now I cannot edit my own profile or dio any thing except woprk in thi porum. No problem, I just don't appreciate being handkled by a jerk with such insensitivity. The man is arbitary and snot nosed brat.
You spew the same drivel over and over and over again. You've had dozens of chances to make your point. You have always been free to babble away--in TD, where folks can choose to ignore you and you don't disrupt serious discussions.

This is your last chance, geistkiesel. If you care to keep posting here, among adults, then:
No more name calling
No more personal attacks​
 
  • #131
baffledMatt said:
Riight. All this coming from a guy trying to convince us that his own theory - which is devoid of calculations or even physics for that matter - proves that SR is wrong.

Don't you think it would be better to try and show us exactly why you think Hurkyl is lying, rather than all this immature name calling?

Hurkyl lying: res ipsa loquitor.

Matt

---à motion ----> M' = M
A__________|______|______|______|______B
-------------t1-----t0------t1-------t2
These are the critical positions as follows:

When M’ = M, t0 = 0 and photons emitted from A and B.

The photon from B arrives on moving platform at t1
Photon from A arrives at t2.
Dt = t2 – t1 = 1 unit time.
V = 1 unit tme.
Assume temporarily M’ the midpoint of A and B at t0 = 0.

[Note: baffledMatt: is this assumption what you were telling the world was a rejection of SR from the get go? It was a convenient assumption that is properly tested below? Not quite as you reported it publically, is it, but what the heck, mentor, SR theorist, propagandist, rote robotic believer?].

At t1, when photon from B arrives, the A photon is assumed to be at –t1.
During dt = 1 the photon from A arrives at t2.

During dt = 1 the A photon travel c = t1 + t1 + 1
or rearranging t1 = (c – 1)/2 = k.

If t1 = k the photons emitted simultabneously in both frames. If t1 < k A the A photon emitted first, otherwise B emitted first.

Simple enough? Reasonable enough? fundamental physics.
See the thread for relativistic an observed expansion. similar logic and reason and physics.
 
  • #132
Doc Al said:
Do you even know what the word "lying" means? It means intentionally saying something that isn't true. Can you point to even one post in which Hurkyl or I said something that wasn't true? Never mind intentionally.

You make wild assertions, and when they are questioned all you can do is sputter and fume. In lieu of reason and argument, you make personal attacks. You bring nothing substantive to the table, geistkiestel.

You spew the same drivel over and over and over again. You've had dozens of chances to make your point. You have always been free to babble away--in TD, where folks can choose to ignore you and you don't disrupt serious discussions.

This is your last chance, geistkiesel. If you care to keep posting here, among adults, then:
No more name calling
No more personal attacks​

Where is there evidence of maturity and adult behaviour in you people? These men are my colleagues? You are all fired.
You certainly aren't teachers, professors, working to instill curiosity and independence in thinking. Just do it! that is your cfrtyive message. message,
the only message.

I call em like I sees 'em. You want that I hold back, be restrained, give yo a few inches so you can hang some body?

No,.
 
  • #133
geistkiesel said:
---à motion ----> M' = M
A__________|______|______|______|______B
-------------t1-----t0------t1-------t2
These are the critical positions as follows:

When M’ = M, t0 = 0 and photons emitted from A and B.

The photon from B arrives on moving platform at t1
Photon from A arrives at t2.
Dt = t2 – t1 = 1 unit time.
V = 1 unit tme.
Assume temporarily M’ the midpoint of A and B at t0 = 0.

Do you see that by defining dt = 1 and v = 1 you have already specified all the distances in the problem?

For instance, (using my notation again, note that your t1 and t2 are my t_B and t_A).

v (t_B - t_A) = 1 = d_A - d_B = \frac{v}{c} L \left(\frac{1}{1-\frac{v}{c}} - \frac{1}{1+\frac{v}{c}}\right)

using the fact that v = 1 and t_B - t_A = 1.

so:

L = \frac{c^2 - 1}{2}.

Now we can calculate the location of the photon from A when the photon from B hits M' (i.e. at t1)

d = ct1 - L = ct1 - \frac{c^2-1}{2} \neq - ct1

hence:

At t1, when photon from B arrives, the A photon is assumed to be at –t1.
During dt = 1 the photon from A arrives at t2.

you are no longer free to make this assumption - it is wrong.

[Note: baffledMatt: is this assumption what you were telling the world was a rejection of SR from the get go? It was a convenient assumption that is properly tested below? Not quite as you reported it publically, is it, but what the heck, mentor, SR theorist, propagandist, rote robotic believer?].

I have no problem with the midpoint as such. The problem is your assumption that the measured distance of A and B from this midpoint will be the same in each frame. So, in each frame they will indeed see M and M' exactly in between A and B, but if you ask each observer to measure the distance between the two they will disagree.

Matt
 
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  • #134
baffledMatt said:
Do you see that by defining dt = 1 and v = 1 you have already specified all the distances in the problem?

I don't think so. 1 is just another symbol. The velocity has to be something I just mae it 1 for convenience. When I make calulation testing t1 I would have to use a eal functional value for he velocity

baffledMatt said:
For instance, (using my notation again, note that your t1 and t2 are my t_B and t_A).

v (t_B - t_A) = 1 = d_A - d_B = \frac{v}{c} L \left(\frac{1}{1-\frac{v}{c}} - \frac{1}{1+\frac{v}{c}}\right)

using the fact that v = 1 and t_B - t_A = 1.

so:

L = \frac{c^2 - 1}{2}.

Now we can calculate the location of the photon from A when the photon from B hits M' (i.e. at t1)

d = ct1 - L = ct1 - \frac{c^2-1}{2} \neq - ct1

hence:



you are no longer free to make this assumption - it is wrong.

How do you calculate A if you don't know if it was emitted simultaneosusly or when it emitted?


Yes I am free to do this as I haven't made any tests yet. I merely continue with the assumption that when M'=M that the photons were emitted simultaneously, which happens to be what happened in this hypo. I make the same claim against you for arbitrarily inserting SR constraints into the problem.

Continuing wih the assumption that the photons were emitted simultaeously when B is detected thenm M = M' at t = 0 is the midpoint hence -t1 the location of the oncoming A photon. The photon reaches t2 during dt = t2 - t1 = t'" if this is more satisfying and let v = v. The distance c moved to arrive at t2 is c(t") = t1(v) + t1(v) + t"(v) or 2(t1v) = ct" - t"(v) or t1v = (ct" - t"v)/2

or t1 = (ct" - t"v)/2v =(t"/2v)(c -v) = k. Now I ask the same question:
Is t1 = k? If so the photons were emitted simultaeously. If t1 < k, the photon left A first, otherwise the photon left B first.
Why did you use the expressions 1 + v/c amd 1 -v/c? was this necessary?

I got, t1 = (ct" - t"v)/2v =(t"/2v)(c -v)

baffledMatt said:
I have no problem with the midpoint as such. The problem is your assumption that the measured distance of A and B from this midpoint will be the same in each frame. So, in each frame they will indeed see M and M' exactly in between A and B, but if you ask each observer to measure the distance between the two they will disagree.

Look again isn't there only the implication that that M' was the midpoint, not necessaily of A and B but of the wave fronts of the photons emitted at somewhere?
This is the divegence point. I say your injection of SR to properly describe the midpoint assumes SR here, does it not?, and therefore, assume they
would not still maintain the charateristic of having the midpoints M = M'? Once you've done this the problem has been hijacked by SR, perhaps hijacked is a tad strong , but you know what I mean.

I think if you looked again I really only assuned the M =M' was the midpoint of the photon wave front, and there is no inference of the A and B location,
Maintaining steadfastly in the moving frame I get an expression that looks the same as yours up to a point.

Well then I just won't ask each observer to measure anything as I see no benefit as this time for anything to measure. Why and what do you measure here?
Now when my expession is rolled out it is aleady to be asked to undergo the test: t1 ?= (t"/2v).(c - v) .

I suspect you don't like the c- v?
 
Last edited:
  • #135
geistkiesel said:
I don't think so. 1 is just another symbol. The velocity has to be something I just mae it 1 for convenience. When I make calulation testing t1 I would have to use a eal functional value for he velocity

No, by specifying v=1 and dt=1 you are setting the time and velocity. distance is velocity multiplied by time, ergo you have also specified distance. Ipso facto your subsequent analysis is erroneous.

How do you calculate A if you don't know if it was emitted simultaneosusly or when it emitted?

I know that they were simultaneous in the stationary frame because that's how the situation was set up. However, this is not to say that they will be simultaneous in the moving frame.

I make the same claim against you for arbitrarily inserting SR constraints into the problem.

I am not inserting SR arbitrarily. I am using results which follow directly from the principle of relativity. I could just as well go through each and every calculation from first principles, but I will still get the same result.

The photon reaches t2 during dt = t2 - t1 = t'" if this is more satisfying and let v = v. The distance c moved to arrive at t2 is c(t") = t1(v) + t1(v) + t"(v) or 2(t1v) = ct" - t"(v) or t1v = (ct" - t"v)/2

Ok, what have you done here. You have equated ct'', which is the distance a photon travels in time t'' to (t1 + t1 + t'')*v, which is the distance the observer moving at velocity v moves in time t1 + t2. What makes you think that these two quantities are equal?! I'm afraid that what you have done here is complete and utter nonsense.

I suspect you don't like the c- v?

This is the least of my concerns!

Matt
 
  • #136
geistkiesel said:
I personally think I am something rare and special [...]

Well, we can't help what you personally think about yourself, but that still doesn't warrant all this hostility.

Besides, if they have been rude to you surely it would be a better show of character not to stoop to their level?

Matt
 
  • #137
baffledMatt said:
Well, we can't help what you personally think about yourself, but that still doesn't warrant all this hostility.

Besides, if they have been rude to you surely it would be a better show of character not to stoop to their level?

Matt
whta else do you want
 
  • #138
Geistkiesel in #127 said:
Some say we humans are free thinkers

I always find it terribly ironic that those who talk most about "free thought" tend to be those who are least likely to consider that others might actually have a good reason to disagree.


Geistkiesel in #131 said:
If t1 = k the photons emitted simultabneously in both frames.

I find it curious that you conclude this, because everything up until this statement has involved only a single frame...
 
  • #139
geistkiesel said:
whta else do you want

Politeness would be a good start.

Being civil is not a sign of weakness. And if you stop with all the vulgarity people might be willing to listen more carefully to what you are saying.

Matt
 
  • #140
Hurkyl said:
I always find it terribly ironic that those who talk most about "free thought" tend to be those who are least likely to consider that others might actually have a good reason to disagree.




I find it curious that you conclude this, because everything up until this statement has involved only a single frame...

t1 = (ct" - t"v)/2v =(t"/2v)(c -v) = k. Yes it involved calculation in the moving frame. To get to this point an assumpotion was made that the photons were emitted simultaneously in the moving frame. Having gotten this far the next step is to test the assumption. If the mesured t1 = k the assumpion was true, if t`< k then the A photon was emitted first, otherwise the B photon was emitted first. All the calculations were performed in the moving frame. So what does "I find it curious ..." mean? Do you find the math, the assumptions, the conclusion erroenous, or am I supposed to guess what you mean? If you have a specific objection I suggest you state it as clearly as you are able so we don't have to read each others minds.
Thee were nio SR assumptions expresssed in the derivaion of the expression. as no SR implications were presented in the problem, without the presentaion being in a contrived mode.
 
  • #141
The curious part is that you could derive a conclusion that has nothing to do with the rest of the post. I went back to reread #131 and I can find nothing that says anything about two different reference frames. I can't even find an explicit reference to one reference frame.
 
  • #142
Hurkyl said:
Geistkiesel: here is your experiment drawn as a diagram:

Code: 
0        0        0
*\       *       /*
* \      *      / *
AZ \     MN    /  BY
AZ  \    MN   /   BY
AZ   \   MN  /    BY
A Z   \  M N/     B Y
A Z    \ M *      B Y
A Z     \M/N      B Y
A  Z     *  N     B  Y
A  Z     M\ N     B  Y
A  Z     M \N     B  Y
A   Z    M  \N    B   Y
A   Z    M   *    B   Y





  Z A    NM     0
  ZA     NM    /*
  ZA     0    / *
  ZA     *   / BY
  0      *  /  BY
  *\    MN /   BY
  * \   MN/   B Y
 AZ  \  M*    B Y
 AZ   \M/N    B Y
 AZ    * N   B  Y
A Z    M\N   B  Y
A Z   M  *   B  Y

Legend:
A, M, B: your A, M, B
Z, N, Y: Your A', M', B'
0: A point where a clock read 0
\, /: photons
*: Multiple things at this point (such as two clocks, or a clock and a photon)

The first diagram is the stationary reference frame. The second diagram is the moving reference frame. Space runs from left to right, and time increases as you go downward.

The first diagram was taken directly from your experimental setup. I placed M and N midway between A/Z and B/Y, and simply drew out the time evolution of the system.

To draw the second diagram, I started with the unambiguous fact that both photons meet precisely when they each meet M. I drew the time evolution backwards, and used the fact that N is midway between Z and Y when M meets N to place where Z and Y should be. I then applied the fact that Z meets A and are both set to zero when the left photon is emitted to finish off the left side of the diagram, and similarly for Y and B. I did, however, have to estimate how N lies relative to M. Any other such choice yields a similar diagram.


Your mistake, as everyone is trying to tell you, is made clear from the diagram. In the moving frame, the clocks are not synchronized; you can see that they are all zero at different times. We see that SR can handle this scenario perfectly well, as long as you don't start with the assumption that synchronization in one frame = synchronization in all frames.




(NOTE: In the second drawing, to keep the diagram small, the lexical distance between A and M is 6 and one-third characters)

I find your diagram confusing and obfuscating. There was a diagram, presented in the opening thread I suggest you deal with the given instead of reinventing the thread language.. No ervyone didn't tell me that because i never made any statement to that effect. If I did use the word "synchroization " it was clear to the meaning that I did not mean it o be cross frame synchronization. Show the signifiicance of your statement in terms of the figure in the opening thread , please. I find it curious you have notcomplained about the clarity of the original figure. So SR can handle the scenario perfectly well. WEll then handle it. I have handled it my way, also perfectly well. Take a few minutes and find a fatal flaw in my analyisi befoe you try to usurp the essence of the thread with what you state, but do not priove, : SR's perfect handling of the scenario.

If you are unable tio explain how photons emitted simulataneioysly to th eeimmediate presence, within a photon wave length of light sensitive strips and not expose thos strip immediately yu are not communicating to me on issues i find critical. If you recall I stipulated ha SR would find he pgotons were not emitted simultabneously. Why are trying to prove what was stipulated?

I suggest you form your argument inline with the given paramjeters of the problem instead of creating diversions, intentionally or negligently.. This is a bad habit you have, chnges he direcion of threads to suit your own purposes, what evre they happenm to be.
 
  • #143
Hurkyl said:
The curious part is that you could derive a conclusion that has nothing to do with the rest of the post. I went back to reread #131 and I can find nothing that says anything about two different reference frames. I can't even find an explicit reference to one reference frame.
So what?
t
What do you think 131 was discussing?. At lest you are beginnng to see that there is only one sginficant frame here. Ths stationary frame provided the simultaneous emission of photons. From that event on the stationary frame iis insconsequential to the physics of the problem, as the relevant events were completed at the instant the photons were emitted by A and B and then immediately exposed the light sensitive strip located within a wavelength of the event, the enmitted phoons.
try looking at the problenm as it you hadn't already assumed the answer, as you have been doing all along. be a physiicist fior this analysis.
 
  • #144
I will I've mentally blended some of the arguments you've made over the past few days; I seem to be responding to the one in the link you kept claiming went undiscussed as opposed to the one in this thread.
 
  • #145
baffledMatt said:
All the time you are assuming that there are all these physical entities which 'have length X' or 'are at time Y'. How do you know this? How do you know that the distance between A and B is 2L? You measure it of course. But hang on, now you haven't actually determined what this entitie's 'true length' is, you have made a measurement - there is no way you can talk about the 'true length' because there is no measurement free way of determining it. Then what SR tells us is how these measurements will differ between intertial frames.

the problem is a hypothetical. I inserted hypothetical measuring paameters consitent withthe laws fo physics. If o hve to lead sem bythe hand on thsi elemnarty level, I am wonder just what you think to=your function is. What you just said sounds as if you are trying to ob scure themeaning of theinvariance of physical lasw in all inertial frames. I described the ls-strips. I describes how pairs of strips were numberd such that the same numbed pairs wee equal distane from he midpoint. Are you telling me SR does not allow finding midpoints of the ls-strips? If you are telling me this I will ignroe you. equal
Themeasurement: using the most accurate stainless steel measuring tape possible tobe constructed, the midpoints ot the numbered ls-striops were located equidistant fro M' n the moving frame.
When the photons were emitted the nearest pair of co=numberd ls-strips were exposed. to the emitted dhotons, situated one wave length from the photons. Are you sayuing this is physially impossible?



[quotwe-baffledMatt]You still think that you are determining some true 'real' property using this measurement. What SR tries to tell us is that the only quantities which do in fact have a 'true' property are the invariant ones (such as rest mass).

Until you think very very carefully about the way you are making your measurements you will never understand this.[/quote]

I am making the exposure of the ls-strips that are placed one wave length from the photons emitted in the stationary frame. If you think this is not a physical possiblity, then say so. I don't rmember saying I was determining a 'real' property. I said I was obtaining a iny mark on an ls_ striop, period. What is so diffiicult in grasping something that is not of a complex nature requiring all the scurrying around.

Are you telling me that SR is so all inclusive and pervasive that it negates the detection of photons at A and B when emitted? you must prove this to me.



baffledMatt said:
Excuse me, are you a physicist or a philosopher? If you want to talk this way then please move your discussion to the philosophy section of the forum. I'm afraid that mathematics is the only way we know of to build a coherent and consistent model of the world around us.

Your suggestion of using 'physical law and reason' instead of hard mathematics is exactly the kind of thinking that gave us Ptolemy. They reasoned that perfect circles were 'physical law' despite what the mathematics was telling them. Do you really want us to go back to that way of reasoning?

Matt
This is just my opinion, but I believe that mathematical models are to a very large extent a corruption on the progress of phsyics. Ptolemy's system worked you know, satisfactorily even thoufgh groundless a a refledtion of natural dynamics. Thus, Ptolemy's model was a precursor to the coruption that relativity theory has had on the progress of science. Sillines, but this is just m yopinion.

At what point in your life did you come to realize that you had eveything covered? I just arrived at that point myself only lastweek.
 
  • #146
baffledMatt said:
The difference between this and religion is that SR is completely logical. You start from the principle of relativity and everything else is deduced from this. So the only thing I got converted to was the principle of relativity - if you want to call that religion then be my guest.

You have not shown us any flaws in SR, only flaws in your interpretation of SR.



There is no paradox, period! Only gross misunderstandings.



This depends on your point of view. I do not consider there to be any physical relevance to two things being simultaneous, so the results of SR do not bother me.

Why do you think there is any significance to things being simultaneous? If two events happen at different locations and the same time then there is no physical way the two events are connected - they are outside of each others light cones. So each event has no idea that it is occurring 'at the same time' as another event. Why do you attach so much significance to things which cannot be causally related?

Matt

How do events have ideas, about other events?

I attach importance to theoreical constructs that enter the physuical domain as pure mental constructs and purport to gao back in time an alter the eality of events already having taken place. You deny this. I assert it to be true,
It isn't that simulateity is disrupted is is the perturbation after an efecnt ahs occued that is claimed as a real physical pheniomenon. tha disturbs me.


A simultaneous eveny of two lights being emitted in a stationary frame occur. This is all. A million of hese evens thisw is all. Only simulatbeous emission fo phoptons is the simultabeiys event. Now comes an obsever, just an observer that no one is pretending applied any physical or other meansurable force on any physical property of the parametrs constuituing the sinmulatneous event and now we have twop ebvenjt. Only the presence of the observer opeates to construct three events from two events., all ths by the mere pesence of an observer.
 
  • #147
Hurkyl said:
I will I've mentally blended some of the arguments you've made over the past few days; I seem to be responding to the one in the link you kept claiming went undiscussed as opposed to the one in this thread.
I unerstand.
 
  • #148
Hurkyl said:
The universe of which I'm aware is full of objects traveling every which way, constantly accelerating to different directions, and without any nice, global structure into which everything fits.

So, there are two very problematic things about this idea; why should there be such a thing as a "stationary universe", and how do we tell what it sees?

i've defined a nice way for determining universal perspective but it includes calculating relative motions for EVERYTHING in the universe. suffice to say it's incredibly accurate and infinitely tedious to run ;D

barring that we can use it to triangulate events from the perspective of relevant local bodies and base our reality /time / space off of those calculations to satisfy on a global level. it may not agree with aliens from beta centauri, but who cares what they think?

And the point is that a reference frame is chosen, and then everything else is defined relative to that.

Relativity does not say that you're not allowed to choose a reference frame as a "standard"; it merely says that any reference frame would suffice.

and my relativity states that you can choose whatever reference frame you want, but when your calculations are vastly disagreeing with the majority, there's a high probability that you're the one that's wrong about "reality"

-------------------

to leave this on a different note, does it really make sense for one person traveling fast and having his perceptions skewed to have HIS OWN, valid reality, complete with slowed stuff behind him and fast stuff in front of him, non-simultaneity, and shrinking rulers? i can only bring myself to think that some of the SR people are down the rabbit hole, smokin with the worm.
 
  • #149
to leave this on a different note, does it really make sense for one person traveling fast and having his perceptions skewed to have HIS OWN, valid reality, complete with slowed stuff behind him and fast stuff in front of him, non-simultaneity, and shrinking rulers? i can only bring myself to think that some of the SR people are down the rabbit hole, smokin with the worm.

Yes.

The most important reason, I think is the following: I expect the laws of physics inside my spaceship to be the same whether I'm in a nice leisurely geosynchronous orbit or hurtling between galaxies at a constant speed of 99% of c.

E.G. If I set something at rest (WRT the ship), I expect it to stay at rest until something nudges it. If I toss a ball at the wall, it should bounce back in the "right" direction. And because of Maxwell's laws, if I send a light signal from aft to stern, I expect it to travel at c.

This is the principle of relativity, and it is what is used to derive everything about SR.



Some other reasons you haven't encountered because you are misleading yourself by only considering situations where there's an obvious "right" choice.

Thought experiments can be set up where the universe consists of only a few objects, none having any sort of special significance that would entail using it to define the "right" frame.

The "right" frame can change; if I'm taking a rocket to Mars, I "should" be in Earth's frame at the start, I "should" be in the solar system's frame in the middle, and I "should" be in Mars's frame at the end. It seems silly to pick a point on my journey and say that I suddenly switch frames!

The "right" frame isn't always the easiest frame to analyze. For instance, calculations might be simpler and natural to do in the frame of the spaceship instead of, say, the frame of the solar system.
 
  • #150
Hurkyl said:
Because we're disagreeing about what SR says when we analyze the exact same events from different frames.

Specifically, Geistkiesel is asserting that both of these diagrams are representing the exact same sequence of events:

Code: 
A        M        B
A\       M       /B
A \      M      / B
A  \    M      /  B
A   \   M     /   B
A    \  M    /    B
A     \M    /     B
A      M   /      B
A      M  /       B
A     M  /        B
A     M /         B
A     M/          B


A       M       B
A\      M      /B
A \     M     / B
 A \    M    /   B
 A  \   M   /    B
 A   \  M  /     B
  A   \ M /       B
  A    \M/        B

We have two relatively stationary light sources (A and B), and an observer who starts in the middle and moves towards A.

The first diagram depicts how things look in the rest frame of the lights, if the lights are activated simultaneously.

The second diagram depicts how things look in the rest frame of the observer, if the lights are activated simultaneously.

However, there is a very important difference between the two diagrams; in the first diagram the photons do not meet M at the same event, however in the second diagram the photons do meet M at the same event.

The conclusion is that these diagrams cannot possibly represent the same events. Among the possible assumptions we can abandon, abanding that of absolute simultaneity is by far the most reasonable; the emission of photons is simply simultaneous in one frame but not the other.

The intrinsic fallacies off Special Relativity Theory.[/size]

Postulates of Special Relativity Theory
The laws of physics and the measure of the speed of light are invariant in all inertial frames.

Experimental Conditions:
  1. One battery with power for two photons only is connected with a single switch to two lights.
    [*] Jill is walking toward Jack who is at the midpoint of the lights.
    [*]When Jill reaches Jack the lights are switched on simultaneously.

Contradictory Observations
  1. Jack observes the lights switched on simultaneously.
    [*]Jill observes the lights switched on sequentially.


Irrational Basis of Special Relativity Theory.[/size]
  1. Violation of conservation of energy principal.
    • Two energy units available.
      [*] Four units of energy claimed.
    [*] No rational explanation for the sequential order of photon emissions.
    [*] Violation of invariance of physical laws in inertial frames.
 

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