SR Simultaneous Lines Drawn in the Sand

[geistkiesel]

ram2048,

Sounds like you have a real solid understanding of this theory!

In the first post of this thread the moving observer at M' was at M the midpoint of sources of photons when the photons were emitted simultaneously. These photons were instantaneously detected in the moving frame as the were emitted in the stationary frame. The moving frame detected the simultaeous emission of the photons in the moving frame. .

Using the detected arrival times of the photons in the moving frame, SR theory calculates that the photons were not emitted simultaneouslly in the moving frame. THE PHOTONS WERE DETECTED SIMULTANEOUSLY IN THE MOVING FRAME AT THE INSTANT THE PHOTONS WERE EMITTED IN THE STATIONARY FRAME.

All you theorists can argue all you want about SR theory, speed of light, Einstein, laws of physics, constancy of the speed of light foreever. The fact of the observation the photons were emitted simultaneously in the moving frame remains invariant under any theoretical perturbation.

Your problem is one of embarrassment when you ponder: "How could I ever have accepted special relativity in the first place?" Like I said, it is your problem, you solve it.

 

[geistkiesel]

Not sure what you are measuring with these photo-sensitive strips.

quote geistkiesel: "Were the photons emitted simultaneously in the stationary frame also emitted simultaneously in the moving frame?"

No.

In the first post of this thread the moving observer at M' was at M the midpoint of sources of photons in the stationary frame when the photons were emitted simultaneously. These photons were instantaneously detected in the moving frame as they were emitted in the stationary frame. The moving frame detected the simultaeous emission of the photons in the moving frame.

This is an experimental observation.

And you say no they were not emmitted in the moving frame simultaneously.

 

[geistkiesel]

Pergatory,

Doc Al is right.

If two lights flash simultaneously (in my frame) and the distance from me to each one is the same at the time of the flashes, then light from the two flashes reaches me at the same time. That's what it means for light speed to be a constant with respect to all observers.

Your bullet analogy let's you down because the bullets are traveling at constant speed with respect to the shooters, but if you are moving wrt the shooters, the bullets are moving at different speeds wrt you.

If you want to get to the point where constant light speed and all its consequences seem more intuitive, stop thinking about bullets!

In the first post of this thread the moving observer at M' was at M the midpoint of sources of photons in the stationary frame when the photons were emitted simultaneously. These photons were instantaneously detected in the moving frame as they were emitted in the stationary frame. The moving frame detected the simultaeous emission of the photons in the moving frame.

What are you talking about " ...seeming more intuitve . . ?.Aren't observations intuitive enough for you?

 

[ram2048]

why must you use a moving frame and a stationary frame?

i think that's what is throwing me off

do one experiment where he's stationary and THEN do the exact same thing when it's moving

combining the two creates unnecessary confusion :P

1) A -> ________________M________________ <- B
1) A ____ ->____________M____________<- ____ B
1) A __________ ->______M______<- __________ B
1) A _________________ xMx _________________ B

2) A -> ________________M________________ <- B
2) A ____ ->______________M__________<- ____ B
2) A __________ ->__________M__<- __________ B
2) A ________________ ->______Mx ___________ B
2) A ______________________ ->__Mx _________ B
2) A ____________________________xMx _______ B

so I'm still not seeing the contradiction. everyone AGREES that the photons don't hit him at the same time in the moving frame. How hard would it be to do the calculations in reverse for the moving frame setup and acquire that the beams WERE emitted simultaneously BECAUSE of the frame shift, extrapolate it using M's velocity towards B.

 

[geistkiesel]

why must you use a moving frame and a stationary frame?

i think that's what is throwing me off

do one experiment where he's stationary and THEN do the exact same thing when it's moving

combining the two creates unnecessary confusion :P

1) A -> ________________M________________ <- B
1) A ____ ->____________M____________<- ____ B
1) A __________ ->______M______<- __________ B
1) A _________________ xMx _________________ B

2) A -> ________________M________________ <- B
2) A ____ ->______________M__________<- ____ B
2) A __________ ->__________M__<- __________ B
2) A ________________ ->______Mx ___________ B
2) A ______________________ ->__Mx _________ B
2) A ____________________________xMx _______ B

so I'm still not seeing the contradiction. everyone AGREES that the photons don't hit him at the same time in the moving frame. How hard would it be to do the calculations in reverse for the moving frame setup and acquire that the beams WERE emitted simultaneously BECAUSE of the frame shift, extrapolate it using M's velocity towards B.

Why do we need two frames?
Because SR theory says that events that are simultaneous in the stationary frame are not simultaneous in the moving frame. We are talking about the same physical event. We must do the experiment with two frames, one stationary and one moving to test the theory. Hence we have the photo-sensitive strips to measuee the emission of the photons.
Here is the contradiciton that everyone is having such a difficult time with.

"Were the photons that were emitted simultaneously in the stationary frame also emitted simultaneously in the moving frame?"[/b ]

There was the record of the phosensitive strips attached to the moving frame that were exposed just when the photons were emitted in the stationary frame. These photo-sensitve strips were within a photon wave length of the emitted photons at A and B in the stationary frame when they wee exposed.

SR theory says, the photons were not emitted simultaneously in the moving frame. SR Theory gets to work backwards in time and redo the physical events that occurred there.

 

[Hurkyl]

why must you use a moving frame and a stationary frame?

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:

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.

 

[Doc Al]

Sure, but also as to the moving observers their clocks are t' = 0. The two '0' are the same.

You cannot arbitrarily set all clocks in O' to read t'=0. Doing so requires assuming that simultaneity is independent of the reference frames. Since that's what we're trying to discover, we can't just assume it.

No stipulation. I already stipulated that a moving observer using SR theory will conclude the photons were not emitted from A and B simultaneously in the moving frame. This is my stipulation. Can you agree to this?

Absolutely not! I don't want anyone making assumptions or stipulations about simultaneity. The entire point of Einstein's simple argument is to deduce the nature of simultaneity, not make assumptions about it.

I didn't stipulate to Einstein's postulate regarding the speed of light. I stipulated that SR theory would predct the photons were not emitted at A and B in the movinng frame. Do you have a problem with this? I am not going to debate the truth or falsity of the 'speed of light' postulate. If you say that the SOL postulate is fundamental to the SR derivation of simultaneity, so be it.

Once again, the point of Einstein's argument is to deduce the relativity of simultaneity, not assume it. The invariant speed of light is fundamental to any gedanken experiment concerning light. Without that, there is nothing to discuss.

The difference goes like this: simultaneity(SR) is placed in an enclosed logical box that cannot be entered and the contents modified, by cleverness, wit, dishonesty or mistake, or stipulation.

Don't be cute. Re-read my post and tell me exactly where you think Einstein's argument fails. If you can't accept the starting point--the invariant speed of light--then there is no point in continuing.

 

[Doc Al]

Doc Al is ambiguous. he is constantly observed to holding little factual tidbits so he can confuse the issue and distrct the flow of the thread. He isn't being honsest is what I am saying.

Please tell me exactly where I am being ambiguous. Refer to my post #2 in this thread. And dishonest? Come now, geistkiesel, have you run out of intellectual ammunition this early in the game?

He really is saying that an observer at M in the stationary frame will see the photons arrive at M simultaneously.

Anyone curious as to what I actually said, can read my own words in post #2.

I agree with your second paragraph. But some using SR theory calculate the photons that arrived at M simultaneously were NOT emitted simultaneously in the moving frame. In fact, before my exile, Doc Al and I discussed this issue in another thread.

We have "discussed" this many times. I am giving geistkiesel a golden opportunity to clearly and unambiguously point out the flaws in Einstein's argument. Is he up to the challenge?

 

[Doc Al]

Doc Al is throwing useless bull **** around to distract.
Read the first post in this thread.

Re-read my response in post #2.

As the moving frame passes the stationary frame when M' in the moving frame was at M in the stationary frame, the photons were emitted in the stationary frame simultaneously,

Right!

and the photons were detected at this very instant simultaneously in the moving frame.

Now what possibly can you mean by this garbled statement? Are you talking about photons being detected by O'? Or O' deducing that they were emitted simultaneously? Speak clearly and stop wasting people's time.

 

[Doc Al]

Read the first post in this thread. As the moving frame passes the stationary frame when M' in the moving frame was at M in the stationary frame, the photons were emitted in the stationary frame simultaneously, and the photons were detected at this very instant simultaneously in the moving frame. Do you understand?

I defy anyone to understand your point. See my last post. Talk sense, man!

 

[Doc Al]

how geistkiesel sneaks in an assumption of simultaneity

In the first post of this thread the moving observer at M' was at M the midpoint of sources of photons when the photons were emitted simultaneously. These photons were instantaneously detected in the moving frame as the were emitted in the stationary frame. The moving frame detected the simultaeous emission of the photons in the moving frame.

Assuming observers in the moving frame were posted at the right positions, then they WILL detect the photon emissions. But what makes you think that they will detect them SIMULTANEOUSLY? Since that is the point we are arguing, please give us your argument. (Note how Einstein's simple argument does not involve multiple moving observers. Why not deal with that argument directly?)

Using the detected arrival times of the photons in the moving frame, SR theory calculates that the photons were not emitted simultaneouslly in the moving frame.

We all agree that the moving observer detects the photons as arriving at different times. Using that fact, plus simple assumptions of the invariance of light speed, Einstein deduces that the moving observer must conclude that the photons were emitted at different times. Every observation made in the moving frame--including the direct observation of the photon emissions by the moving observers--must agree with this conclusion!

THE PHOTONS WERE DETECTED SIMULTANEOUSLY IN THE MOVING FRAME AT THE INSTANT THE PHOTONS WERE EMITTED IN THE STATIONARY FRAME.

Again, you merely ASSume, where Einstein argues.

All you theorists can argue all you want about SR theory, speed of light, Einstein, laws of physics, constancy of the speed of light foreever. The fact of the observation the photons were emitted simultaneously in the moving frame remains invariant under any theoretical perturbation.

I truly believe that you believe this. But you are still wrong. Rather than add questionable assumptions to Einstein's gedanken experiment, please deal directly with Einstein's simple argument.

Your problem is one of embarrassment when you ponder: "How could I ever have accepted special relativity in the first place?" Like I said, it is your problem, you solve it.

Geistkeisel, I am making a special effort in this thread to be nice. Why don't you do the same?

 

[geistkiesel]

A Simultaneous Line in the Sand for Doc Al

I defy anyone to understand your point. See my last post. Talk sense, man!

The instant photons were simultaneously emitted from A and B in the stationary frame the photo-sensitve strips in the moving frame were exposed (|||) at both ends of the moving frame, at locations equally spaced from M'. This is the point, the only point. For your convenience we give another picture.

|||----M'----||| -->moving frame-->
-A-----M-----B-| XX stationary frame XX

This is the picture the instant photons were emitted from A and B in the stationary frame.

Said another way, the instant the photo-sensitive strips were exposed in the moving frame by photons emitted in the stationary frame..

Is this enough "sense talk, man"?

I title this: A Simultaneous Line in the Sand for Doc Al.

If you were from Texas, or had spent any time in Texas, maybe, just maybe you would be able to understand. And this even though it is common knowledge that Texans have half their brains tied behind their back, leaving one loose piece of gray matter to rattle around inside their skull cavities.

You defied anyone to understand the point. OK, someone from Texas, splain it to Doc Al.

 

[geistkiesel]

Doc Al's special effort fails the nice simultaneity test, again..

Again, you merely ASSume, where Einstein argues.

I truly believe that you believe this. But you are still wrong. Rather than add questionable assumptions to Einstein's gedanken experiment, please deal directly with Einstein's simple argument.

Geistkeisel, I am making a special effort in this thread to be nice. Why don't you do the same?

You don't know how to be nice. There were no added assumptions that corupted Einstein's gedunken. You just haven't realized that you've lost this game.

As from me to you, this is as nice as it gets.

 

[russ_watters]

it is also useful if the thiought proes the theory wrong.

If the thought process of the theory is wrong, then it can easily be shown to be wrong through experimentation. You you can't prove that a theory is wrong if you don't address what the theory says. You are stating (assuming, as Doc says) the theory is wrong and building a thought experiment around how you think the universe should work, then offering it up as a proof that the theory is wrong. Sorry, science doesn't work that way.

Depending on the theory you apply to the thought experiment, the outcome is different. Which is right and which is wrong? Well, that's a question answered by experimentation.

What's funny about this is you think you're making an argument against Relativity, but what you are actually doing is demonstrating you don't even understand the scientific method, much less Relativity. The other guys here aren't so much defending Relativity as trying to explain to you what it says.

 

[Doc Al]

geistkiesel's assumptions

The instant photons were simultaneously emitted from A and B in the stationary frame the photo-sensitve strips in the moving frame were exposed (|||) at both ends of the moving frame, at locations equally spaced from M'. This is the point, the only point. For your convenience we give another picture.

Can observers in the moving frame detect the emission of the photons? Yes.
Are the marks on the photo-sensitive strips (caused by the photon emissions) in the moving frame equally spaced from the point M' (which passed M at the exact moment that the clock at M read t=0): YES!
Do the moving observers detect the photon emissions as happening simultaneously: NO!

By building incorrect assumptions into your "thought" experiment, you have left the realm of real physics. (As we know it today.)

Note that Einstein makes no such assumptions--and is able to simply deduce the relativity of simultaneity. Why not address Einstein's actual argument?

 

[Doc Al]

geistkiesel's incorrect assumptions

There were no added assumptions that corupted Einstein's gedunken. You just haven't realized that you've lost this game.

You ASSumed that:

(1) The marks on the photo-sensitive strips (caused by the photon emissions) in the moving frame are equally spaced from the point M' (which passed M at the exact moment that the clock at M read t=0): True!
(2) That the moving observers detect the photon emissions as happening simultaneously: Not true!

As long as you insist on adding these assumptions, there is no point in continuing the discussion.

However, if you would like to discuss Einstein's actual argument--which you refer to constantly but obviously fail to grasp--have at it. If you truly understand Einstein's point, this should be no problem--since he makes fewer assumptions than you do.

 

[baffledMatt]

The instant photons were simultaneously emitted from A and B in the stationary frame the photo-sensitve strips in the moving frame were exposed (|||) at both ends of the moving frame, at locations equally spaced from M'. This is the point, the only point. For your convenience we give another picture.

|||----M'----||| -->moving frame-->
-A-----M-----B-| XX stationary frame XX

This is the picture the instant photons were emitted from A and B in the stationary frame.

Said another way, the instant the photo-sensitive strips were exposed in the moving frame by photons emitted in the stationary frame..

But how did you determine the distance between the photosensitive strips? If you made it the same length as A->B whilst in the moving frame then you have a problem because in the stationary frame this distance will be observed to be shorter than A->B due to Lorentz contraction. Thus in the stationary frame it is impossible for them to fall over A and B at the same time.

Ok, so you determined the length when the moving frame was actually stationary. But this doesn't help you either because when they start moving the moving observer will observe the distance between A and B to contract. Hence, again the strips cannot both be over the lights at the same instant in this frame.

The only way out of this mess is to accept the loss of simultaneity. This is why I suggested looking up the 'pole vaulter paradox' earlier because it points this out quite beautifully.

Matt

 

[ram2048]

makes no sense for SR to resolve that the photons were NOT emitted simultaneously.

it's a "Given" part of the experiment that they WERE emitted simultaneously as outlined in Einstein's original set up

there's a billion ways we can PROVE that they were emitted simultaneously hooking them up to synchronized clocks, photosensitive strips, whatever. that's not part of the argument, though. It's not even a possibility.

i think you SR supporters are somehow taking what einstein said the wrong way.

 

[wespe]

makes no sense for SR to resolve that the photons were NOT emitted simultaneously.

it's a "Given" part of the experiment that they WERE emitted simultaneously as outlined in Einstein's original set up

it's a "Given" part of the experiment that they WERE emitted simultaneously as outlined in Einstein's original set up

No it's not given or automatically assumed. It is deduced, because the stationary midpoint observer received the lights at the same time. The midpoint observer just happens to receive the lights at the same time, that's the setup. Only because of this you can deduce that they were emitted simultaneously *in the stationary frame*, you can' assume anything else. You can't analyse this like you have a bird's eye view and like you can see everything at the same time. But if you want a graphical view according to SR, check this link:

http://casa.colorado.edu/~ajsh/sr/simultaneous.html

 

[ram2048]

yeah i saw that one from the other thread.

i still think the moving observer KNOWING he is moving towards B can extrapolate using his velocity/acceleration backwards to determine that they were emitted simultaneously.

i believe this is the proper way to come to the conclusion in the experiment, not calculate forward and find out that your perceptions are skewed, calculate backwards and find out where "reality" is.

 

[ram2048]

in any case this setup is different from cerulean and vermilion by virtue of being contained within 2 other bodies (the photon emitters) which have a known property of being "fixed" in the universe which provides excellent reference points to capture movement data to work backwards from.

you wouldn't have that luxury in the example in that link

 

[wespe]

yeah i saw that one from the other thread.

i still think the moving observer KNOWING he is moving towards B can extrapolate using his velocity/acceleration backwards to determine that they were emitted simultaneously.

Yes, but the moving observer in fact considers himself stationary, and considers the embankement moving. If he extrapolates the values of his own measurements (his own speed = zero), he finds the SR result. Why would he think his measurements are faulty and correct them according to stationary frame's measurements? It's mutual. You can't determine who is really really really moving. Even if you assume there's a preffered frame, you can't detect your speed relative to it by any experiments.

 

[wespe]

in any case this setup is different from cerulean and vermilion by virtue of being contained within 2 other bodies (the photon emitters) which have a known property of being "fixed" in the universe which provides excellent reference points to capture movement data to work backwards from.

You assume absolute space by saying they are fixed. Otherwise, you can't say that the photon emitters can be a reference. And the speed of light is independent of its source, so the movements of the photon emitters does not matter. (And as far as I know, there is no blue/red shift for a single photon) In short, there is no reference to detect your own movement in space, you always consider yourself at rest.

 

[ram2048]

you've got to be kidding!

that can't be the way it works. that's completely backwards thinking :D

are you telling me when they plan a mission to Mars they calculate that Mars is traveling closer, not the probe/lander/vehicle is traveling towards it? :|

 

[wespe]

you've got to be kidding!

that can't be the way it works. that's completely backwards thinking :D

are you telling me when they plan a mission to Mars they calculate that Mars is traveling closer, not the probe/lander/vehicle is traveling towards it? :|

That looks equally valid to me, results of the calculations would be the same. But I guess you would normally plan a mission from a third frame's perspective (the earth).

 

[geistkiesel]

No it's not given or automatically assumed. It is deduced, because the stationary midpoint observer received the lights at the same time. The midpoint observer just happens to receive the lights at the same time, that's the setup. Only because of this you can deduce that they were emitted simultaneously *in the stationary frame*, you can' assume anything else. You can't analyse this like you have a bird's eye view and like you can see everything at the same time. But if you want a graphical view according to SR, check this link:

http://casa.colorado.edu/~ajsh/sr/simultaneous.html[/QUOTEYour link is bogus, unproved crap. Did you gothrough the maths that justifies what the link says?
No
you are talking silly. The photons were emitted simultaneoulsy and exposed the photo-sensitive deectors in the moving iframe as they were emitted. The fact that the photons were emitted at the same time has nothing to do with the obsever at M seeing teh photons later. This is given in the problem ()"relativity" pages 25 -27). . In this therad SR is assumed to predict that the photons were not emitted similtaneously.

Wespe, why do you come barging in here not even half prepared? You're screwing up a decent thread. Where do you get all that "you can't assume anything" crap?" prove it. You come here with your stupid useless intervention totally ignorant of what is happening, but so full of answers. Go away.

 

[geistkiesel]

Yes, but the moving observer in fact considers himself stationary, and considers the embankement moving. If he extrapolates the values of his own measurements (his own speed = zero), he finds the SR result. Why would he think his measurements are faulty and correct them according to stationary frame's measurements? It's mutual. You can't determine who is really really really moving. Even if you assume there's a preffered frame, you can't detect your speed relative to it by any experiments.

BS. It is given he knows his velocity and can measure it as he crosses M when the hotons are emitted. You're just as ignorantly dishonest as Doc Al, your mentor.. Otherwise the propblem is nothing. Yes you can. Blue/red analyses. Also each frame can emit 1 second inteval pulses. The stationary (slower) frame will read the moving frame pulses as slower than his two seconds. Likewise, the moving frame will read the stationary frame pulse rate as faster than his own. You say no absolute time? prove it.

Why ae you making things up? Showing off your childish television learned physics? Just to sabatoge and get even for your embarrassing loss awhile back?

Answer the question of the photo-sensitive strips being exposed when the photons are emitted simutaneously. These strip are located equidistant from the midpoint M' in the moving frame. Get up tp speed Wespe or get off the bus. Asswer this one question posed here. can you do this or do you want to measure the SOL first?.

 

[baffledMatt]

Your link is bogus, unproved crap. Did you gothrough the maths that justifies what the link says?
No
you are talking silly.

and I was just about to say exactly the same thing about your link.

Answer the question of the photo-sensitive strips being exposed when the photons are emitted simutaneously. These strip are located equidistant from the midpoint M' in the moving frame.

Errrm, hello?

*pointing to the last post I made*

Matt

 

[geistkiesel]

wespe's windmills

in any case this setup is different from cerulean and vermilion by virtue of being contained within 2 other bodies (the photon emitters) which have a known property of being "fixed" in the universe which provides excellent reference points to capture movement data to work backwards from.

you wouldn't have that luxury in the example in that link

Ram2048 Beware wespe. This is theone that started the other SR ain't working thread until surrenduring to frustration. He taks a lot of you can't do this and that. The photons were emitted simultaneously when M' was at M, THis is a given , You don't ahve to prove it. The velocity of the moving frame is determined whjen passing through M. Cerulean, aslo, has no proof of anyhing. However, it shows the inanity of SR. A physical event occurred and by them ere fact that an observer was thrown in at some time later that observer can make a physical alteration of the sequence of the emitted photons just because he is an observer, never having any contact whith any of the mechanics of thephoton, their sources, the photons themselves. This is how inane SR really is.

Wespe pisses me off. he has a limited extent of thinking range which he is unwilling to extend. All thos things he said about the experiment of this thread is bogus. he hasn't read the thread and knows not what is happening. Your figure is correct. I would remind you that th ethread stipulates that SR will predict the photons weren'y emitted simultaneously,

Have your quiestioners answer, among other questions, how can the photons be detected simultaneously in the moving frame, simultaneousl and marked and identified as equidistant from the midpoint of those exposed strips? No clocks needed, AN instantaneous event. The midpoint of he moving frame was determined the same way as the midpoint in the stationary frame, by the laws of physics that are invariant in all inertial frames., by the photo-sensitive strip, yet later be calculated as having occurred nonsimultaneously?

Im going to be off line for a few hours. Myself, I am not equipped to the taking of prisoners. Shoot anybody who surrenders.

 

[wespe]

Your link is bogus, unproved crap. Did you gothrough the maths that justifies what the link says?

It just shows graphically that it is possible for two frames to have relative simultaneity, when you abandon the idea that time is absolute.

Noyou are talking silly. The photons were emitted simultaneoulsy and exposed the photo-sensitive deectors in the moving iframe as they were emitted.

You say "emitted simultaneously" but you don't say in which frames. You just assume it is in both frames. That is the argued point but you start by assuming it.

The fact that the photons were emitted at the same time has nothing to do with the obsever at M seeing teh photons later. This is given in the problem ()"relativity" pages 25 -27). . In this therad SR is assumed to predict that the photons were not emitted similtaneously.

The only facts in an experiment are the measurements. Don't assume "something is so and so in reality". You can not dictate what reality should be.

Wespe, why do you come barging in here not even half prepared? You're screwing up a decent thread. Where do you get all that "you can't assume anything" crap?" prove it. You come here with your stupid useless intervention totally ignorant of what is happening, but so full of answers. Go away.

I'm just saying "don't assume anything except the measurements". The measurement is not "they were emitted simultaneously in stationary frame", that is the conclusion. The measurements are "M received the photons simultaneously", "M is equadistant from A and B", "speed of light is constant".

You have no math and no answers. When you are disproven by calculations you say "maybe so" "calculations must be flawed" "reality is like in fact this". And you didn't stop posting in my thread even I asked you nicely, why should I go away?

 

[geistkiesel]

But how did you determine the distance between the photosensitive strips? If you made it the same length as A->B whilst in the moving frame then you have a problem because in the stationary frame this distance will be observed to be shorter than A->B due to Lorentz contraction. Thus in the stationary frame it is impossible for them to fall over A and B at the same time.

Ok, so you determined the length when the moving frame was actually stationary. But this doesn't help you either because when they start moving the moving observer will observe the distance between A and B to contract. Hence, again the strips cannot both be over the lights at the same instant in this frame.

The only way out of this mess is to accept the loss of simultaneity. This is why I suggested looking up the 'pole vaulter paradox' earlier because it points this out quite beautifully.

Matt

I don't like you Matt, you've been paying attention. They determined the midpoint using the same laws of physics as the stationary frame did. Also, the strips of photo-sensitive material is fractions of a micron wide, thousand of strips in a section. Each strip<< photon wave length.. The sections holding the strips are long enough so that shrinking in the moving frame is accounted for. Each pair of A', B' strips is equidistant fronm the midpoint M'. Assume the moving platform will shrink 100 units from velocity considerations. We make the sections at each end of A' and B' 200 units long er, totalling 400 units overkill. with the strips covering the whole 200 units. Overlap, overkill.

 

[geistkiesel]

and I was just about to say exactly the same thing about your link.



Errrm, hello?

*pointing to the last post I made*

Matt

matt, I answered another post of yours with the answer, bsically the midpoint of the strips was determio=ned by the same laws of physics thatadetermined M in the stationary frame. Each strip is ifractio s of a micron wide. Thousand in a section . The two section much longer 9calulated fro SR)to assure that the stips will overlap A and B whe the moving frame passes? OK uMMRRR?

 

[jdavel]

ram2048 said, "it's a "Given" part of the experiment that they WERE emitted simultaneously as outlined in Einstein's original set up"

Not quite! They were simultaneous in the stationary frame, but, as it turns out, they weren't simultaneous in the moving frame. That's not an assumption; it's a conclusion based on the assumption that c is the same in both frames.

Here's "Einstein's original set up":

IN THE STATIONARY FRAME THE FLASHES ARE SIMULTANEOUS and are equidistant from the moving observer at the time of the flashes. So, the stationary observer sees light from the two flashes reach the moving observer at different times.

The moving observer agrees, light from the two flashes reached him at different times. Then he looks at the marks that the flashes made on his train, sees they are at equidistant from his seat on the train. Since he knows that c was the same for the light of both flashes, he concludes that THE FLASHES WERE NOT SIMULTANEOUS IN THE MOVING FRAME.

 

[baffledMatt]

They determined the midpoint using the same laws of physics as the stationary frame did.

What do you mean by this? Did they determine the length whilst the moving frame was actually moving or not?

Also, the strips of photo-sensitive material is fractions of a micron wide, thousand of strips in a section. Each strip<< photon wave length.. The sections holding the strips are long enough so that shrinking in the moving frame is accounted for. Each pair of A', B' strips is equidistant fronm the midpoint M'. Assume the moving platform will shrink 100 units from velocity considerations. We make the sections at each end of A' and B' 200 units long er, totalling 400 units overkill. with the strips covering the whole 200 units. Overlap, overkill.

Hmm, if you like. But by this argument you are only able to determine the level of simultaneity to an accuracy set by the length of your strips. Do you see what I'm getting at? Say you do the experiment with strips of length 200 units and find that they do in fact both detect the emitted light. You say that this proves that the emission was simultaneous. However, if the emissions at A and B were in fact separated by a time interval t < 200 * v then you would still have detection on both strips even though the emission was not simultaneous. So to prove real simultaneity you MUST make your strips of vanishing length.

Matt

EDIT: changed some numbers to avoid possible confusion

 

[geistkiesel]

It just shows graphically that it is possible for two frames to have relative simultaneity, when you abandon the idea that time is absolute.

nothinmg was abanded. Th estrips were placed to coincide with A and B within a wave length of theemitted photons. The very instant the photons were emitted, what 10-6 of a second as an instant. You are the one that is asserting time is not absolue, prove it.

You say "emitted simultaneously" but you don't say in which frames. You just assume it is in both frames. That is the argued point but you start by assuming it.

emitted simultaneously in the moving frame. Detected as the photons were emitted the photo-sensitive strips attached to the moving frame.one wave length from the sources at A and B.

The only facts in an experiment are the measurements. Don't assume "something is so and so in reality". You can not dictate what reality should be.

The photons were exposed as the photons were enmitted. This means the photons were emitted simultaneously in the moving frame because that is when they were detected. I can dictate the truth when I see it. YOu know nothing. You have a childs view of SR and you are talking to me like they talked to you at one time. It sounds like you were beaten intio shape.

I'm just saying "don't assume anything except the measurements". The measurement is not "they were emitted simultaneously in stationary frame", that is the conclusion. The measurements are "M received the photons simultaneously", "M is equadistant from A and B", "speed of light is constant".

See there you go. You are either consciously lying or you haven't read the thread. The given is that the photons were emitted just as M' passed through M. Tere was no wait to determine this. The ones putting on the experiment did this. Do you have that yet after having it drilled in what you call a head a few dozen tuime? Why are you so carelss?" We all err. But with you its cronic. You have to make up crap to win don't you, just like Doc Al taught you. He is so proud.

You have no math and no answers. When you are disproven by calculations you say "maybe so" "calculations must be flawed" "reality is like in fact this". And you didn't stop posting in my thread even I asked you nicely, why should I go away?

Evry word out of your mouth is a lie. I stipulated at the beginning that SR would predict the phoytons were no emitted simultanoulsy. Go back to ANdorra or from wheever you originated. So whaT if i didn'tstop posting in "your" thread. So sue me. Actually i am cleaning up your unfinished business that you ran from like a frightend child. Why should you go away? because you bore me.