Today Special Relativity dies

[wespe]

OK. So the guy moving to the left concludes that the light on the left was emitted before the light on the right. Let's say that there was a guy running to the right then he would have to conclude that the light on the right was emitted before the light on the left. BOTH CAN'T BE TRUE.

Both must be true. Given the constant speed of light, there is no other explanation (well, if you have one...). Look at it this way: simultaneity is defined by what the midpoint observer concludes in this setup. Since there can be any number or midpoint observers moving at different speeds, each one concludes differently, and each of them are correct according to themselves. That's relative simultaneity, as opposed to absolute (one that everyone agrees on) simultaneity. If you have a better definition of simultaneity, I'd like to hear that. Of course, defining simultaneity has consequences. It must be consistent with what you define as time, and with casuality. Note that all observers still agree that events occurring at a single point in space are absolutely simultaneous. Only events separated by distance causes disagreement. But this disagreement does not yield any casuality paradoxes, since SR also limits all speeds to be below c. Considering the speeds involved in our daily lives, it has little impact and not a big deal really (except when you need very high precision and stuff)..

Take care.

 

[wespe]

hehe yeh it's things like this that make me a skeptic :D

good work spotting it though, Great One. apparently it's not easy to spot :|

Ram1024, that's funny, but, did you read #93 and #96? Hurkyl still thinks simultaneity was measured in "picture frame". Maybe you should make it clear before wasting any more of his time.

 

[ram1024]

the consequences are way too far-fetched to believe in.

Length Contractions, Time Dialation, No Absolute Time, No Absolute Space...

it's like alice in wonderland on your guys' side of the fence :D

i'll define my version some time tomorrow i think. sure would like more people to toss in their opinions first of all, though.

it's intriguing that people who know SR still can't agree what the answers are to these.

 

[russ_watters]

the consequences are way too far-fetched to believe in.

Length Contractions, Time Dialation, No Absolute Time, No Absolute Space...

it's like alice in wonderland on your guys' side of the fence :D

i'll define my version some time tomorrow i think. sure would like more people to toss in their opinions first of all, though.

it's intriguing that people who know SR still can't agree what the answers are to these.

Clearly, this approach isn't working. Perhaps you'd be more inclined to accept SR if you started looking at what the evidence actually shows. Real experiments showing these "alice in wonderland" concepts like time dilation and length contractions.

How about GPS satellites? Do you know how they keep their clocks synchronized?

How about speed of light measurements: do you know that they all give the same answer?

 

[ram1024]

Hurkyl has unfortunately come up with the "correct" answers for #2 #3 and #4, but I'm not sure he acquired them through SR since he didn't really elaborate.

if he has indeed come to that conclusion based on SR then i am pretty much SOL for refuting it since that's what my relativity would say as well

was trying to hide him under the mattress or something so i could get a bit further along in the discussion, but you just HAD to go and point him out

 

[geistkiesel]

Hurkyl has unfortunately come up with the "correct" answers for #2 #3 and #4, but I'm not sure he acquired them through SR since he didn't really elaborate.

if he has indeed come to that conclusion based on SR then i am pretty much SOL for refuting it since that's what my relativity would say as well

was trying to hide him under the mattress or something so i could get a bit further along in the discussion, but you just HAD to go and point him out

you gave up too much., too soon. try this one out for size.
All moving frame values are non-primed with the exception of M’, the consistent location of the observer O in the moving frame.

At no time is there an inference that M’ was at the midpoint of the A and B photons emitted in the stationary frame.

To demonstrate the following:

Einstein’s moving train calculation indicating when the oncoming B photon is detected at t1 the A photon was located at a position consistent with –t1. Said in other words, as t1 is determined from t0 which locates M’ at t0, the A and B were equidistant to M’(t0) when t = t1.

Proof:
A moving observer located at M’ on a moving frame passes through the midpoint M of photon sources located at A and B in the stationary frame just as A and B emit photons. M’ is moving along a line connecting A and B, toward B.

At this instant the moving source t = t0. Later the moving observer detects the photon from B at t1, and later the photon from A at t2. The observer has measured her velocity wrt the stationary frame as v. Determine the position of the A photon at tx in terms of t0, t1, t2, and v when the B photon was detected at t1.

The photon from A must reach the position of M’ when t = t2. Therefore, the distance traveled by the A photon during Δt = t2 – t1, is Δtc. This is equal to the distance cΔt = vΔt + vt1 + vtx . Now we rearrange somewhat to arrive at, vtx = vΔt – cΔt + –vt1. Now as vΔt - cΔt is just -vtx - vt1

vtx = -vtx - vt1 – vt1

2tx = -2t1

tx = -t1

Therefore, in the moving frame the photon from A and the photon from B were equidistant from M’(t0) at t1.

 

[O Great One]

OK. So the guy moving to the left concludes that the light on the left was emitted before the light on the right. Let's say that there was a guy running to the right then he would have to conclude that the light on the right was emitted before the light on the left. BOTH CAN'T BE TRUE.

Both must be true. Given the constant speed of light, there is no other explanation (well, if you have one...). Look at it this way: simultaneity is defined by what the midpoint observer concludes in this setup. Since there can be any number or midpoint observers moving at different speeds, each one concludes differently, and each of them are correct according to themselves. That's relative simultaneity, as opposed to absolute (one that everyone agrees on) simultaneity. If you have a better definition of simultaneity, I'd like to hear that. Of course, defining simultaneity has consequences. It must be consistent with what you define as time, and with casuality. Note that all observers still agree that events occurring at a single point in space are absolutely simultaneous. Only events separated by distance causes disagreement. But this disagreement does not yield any casuality paradoxes, since SR also limits all speeds to be below c. Considering the speeds involved in our daily lives, it has little impact and not a big deal really (except when you need very high precision and stuff)..

Take care.

It is logically impossible that both statements are true. Let's imagine that the platform is balanced like a teeter-totter and when the light is emitted the platform tips in that direction. So the guy running towards the left thinks that the platform tips to the left and then to the right, and the guy running towards the right thinks the platform tips to the right and then to the left. Try to explain how they are both correct!

 

[ram1024]

actually it all suits my purposes. i don't care to retute SR as long as it sees things MY way ;D

 

[geistkiesel]

As has already come up, #4 has not been formulated in a way consistent with SR.

In other words, you're assuming the answer before you "do" the experiment.


If you accelerate the train, you run into the problem of no rigid bodies, and if both trains had been moving with different constant velocitys (possibly zero), then it cannot be the case that the two setups are identical (particularly the same proper length) and that the endpoints can coincide simultaneously in either of their two rest frames.


Furthermore, yet again I can only assume that when you say "simultaneous" you mean in the frame you draw pictures (which I'll now call the "picture frame")


Anyways, if I assume you do something like accept there's a rigid body problem, or allow one train to be longer than the other, or something or other, I deduce that both observers will observe the right photon before the left photon. If you can get the two observers along the same worldline, then they will detect the right photon simultaneously, and similarly for the left photon.


This is consistent with my previous answers where, in both case #2 and #3 (under the assumption that "simultaneously" was measured in the picture frame), I stated that the observer would not detect both photons simultaneously.

Hurkyl, the following is similar to the problem you had me solving a while back. This should be slam dunk easy for you.

All moving frame values are non-primed with the exception of M’, the consistent location of the observer O in the moving frame.

At no time is there an inference that M’ was at the midpoint of the A and B photons emitted in the stationary frame.

To demonstrate the following:

Einstein’s moving train calculation indicating when the oncoming B photon is detected at t1 the A photon was located at a position consistent with –t1. Said in other words, as t1 is determined from t0 which locates M’ at t0, the A and B were equidistant to M’(t0) when t = t1.

Proof:
A moving observer located at M’ on a moving frame passes through the midpoint M of photon sources located at A and B in the stationary frame just as A and B emit photons. M’ is moving along a line connecting A and B, toward B.

At this instant the moving source t = t0. Later the moving observer detects the photon from B at t1, and later the photon from A at t2. The observer has measured her velocity wrt the stationary frame as v. Determine the position of the A photon at tx in terms of t0, t1, t2, and v when the B photon was detected at t1.

The photon from A must reach the position of M’ when t = t2. Therefore, the distance traveled by the A photon during Δt = t2 – t1, is Δtc. This is equal to the distance cΔt = vΔt + vt1 + vtx . Now we rearrange somewhat to arrive at, vtx = vΔt – cΔt + –vt1. Now as vΔt - cΔt is just -vtx - vt1

vtx = -vtx - vt1 – vt1

2tx = -2t1

tx = -t1

Therefore, in the moving frame the photon from A and the photon from B were equidistant from M’(t0) at t1.

 

[wespe]

It is logically impossible that both statements are true. Let's imagine that the platform is balanced like a teeter-totter and when the light is emitted the platform tips in that direction. So the guy running towards the left thinks that the platform tips to the left and then to the right, and the guy running towards the right thinks the platform tips to the right and then to the left. Try to explain how they are both correct!

That's because there is no totally rigid objects in reality. Imagine that the platform is several light years long. When one side goes down, this event cannot have an immediate effect on the midpoint or the other side. Even if the change propagates at light speed, it has to travel for several years to reach the midpoint or to make the other side go up. Therefore, what the observer sees is more up-to-date than what he feels under his feet. Was this what you meant?

 

[O Great One]

OK. Let's try again. Let's say that when the light is emitted, the emitter blows up in a huge explosion. Somebody is standing off in the distance observing this. He either observes the explosion on the left and then the explosion on the right or he observes the explosion on the right and then on the left.

 

[ahrkron]

That will depend on how that person is moving. It is the original situation all over again. If he is moving to the left, he will get first the light from the left, and since he measures the speed of that light to be the same as that from the right, he is entitled to deduce that the blast from the left occurred first.

Same happens if the person in the distance is moving to the right.

 

[ram1024]

the emitter exploding is a good one, Great. i was tempted to use explosion as emitters but was afraid someone would say something crazy like "the explosion imparts and inertial vectored thrust quotient based on non-linear cohesian and sub temporal disjunction, and therefore the light particles get immersed in an endothermic tesla-radiation that elevates their states to 15th dimensional particles. SR predicts that these particles exist everywhere at once. Good Game, ram1024, YOU LOSE"

 

[geistkiesel]

In this case, then, indeed, (true, true, true).


However, I would like to comment on other things you have said:



This will not work. There is no such thing as a rigid body, so you cannot use that as a way to keep things in sync.

In fact, if you sync the clocks while they're stationary (in the background frame), then accelerate the platform, the clocks cannot be synchronized in their rest frame, nor in the background frame.

This is easy to see in the background frame; due to length contraction, one of the clocks must have been displaced more than the other.




Which cannot happen, according to SR, unless the situation is trivial; either the two clocks are at the same place, or two frames are the same.

(for simplicity, I'm speaking in one spatial dimension)


I'm lagging somewhat behind the course of the conversation (darned TV!) but I'm going to post this anyways.

Can't you rotate the clocks 90 degrees, accelerate and then rotate back to align as before acceleration?

 

[geistkiesel]

A better way to look at it is the way JCSD described. Nothing "causes" them to be unsynchronized in other frames, they simply are unsynchronized. There is no way that the postulates of SR can hold and for simultaneity to be absolute. So the question is, Do the postulates hold?

Experimentation has answered with an emphatic "YES".



No, you are expected to accept it because the evidence says so. And even if you don't accept it, surely you must be able to accept that simply assuming that SR is false does not disprove it.



And why not? Experimentation is the final court of appeals in science. If you aren't open to that, then there is no hope for you.



That's correct, because nothing was "done" to the clocks, period. It's not as though some invisible agent resets the clocks so that they are out of synch when a moving observer passes by. It is just a simple consequence of the fact that, in our universe, the laws of physics and the speed of light are the same for everyone.



But we can discern that the clocks don't tick at the same rate for all observers.

Tom, Can't you rotate the clocks 90 degrees transverse to the accelerated direction and when velocity is achieved rotate the clocks -90 degrees?

 

[Hurkyl]

but I'm not sure he acquired them through SR since he didn't really elaborate.

As Tom said, it's just geometry.

The method is consistent with SR, but in this problem, it is also consistent with Newton. No switching of frames of reference was involved, and that seems to be the particular disagreement you have with SR.

A lot of people detracting from SR forget that it has all the "ordinary" tools for analyzing a single reference frame too! (e.g. geometry, vectors, calculus)

Can't you rotate the clocks 90 degrees, accelerate and then rotate back to align as before acceleration?

That's an interesting question; I hadn't pondered if there was any simple 2-D way to do this.

the emitter exploding is a good one, Great. i was tempted to use explosion as emitters but was afraid someone would say something crazy like "the explosion imparts and inertial vectored thrust quotient based on non-linear cohesian and sub temporal disjunction, and therefore the light particles get immersed in an endothermic tesla-radiation that elevates their states to 15th dimensional particles. SR predicts that these particles exist everywhere at once. Good Game, ram1024, YOU LOSE"

Bah! That's silly!


They're only 14th dimension particles.

 

[wespe]

OK. Let's try again. Let's say that when the light is emitted, the emitter blows up in a huge explosion. Somebody is standing off in the distance observing this. He either observes the explosion on the left and then the explosion on the right or he observes the explosion on the right and then on the left.

Do you mean: "those simultaneity conclusions were harmless illusions, but let's add something real like explosions". It doesn't matter. The order of events can be really different for different observers. None of them is more correct or real than the other. You can't be at both places to see which event "really" occurred when. As long as there is no paradox, what is your objection?

Actually, O Great One, I think you can ask such questions in the relativity forum and get better answers there. [edit: provided that you will ask questions and you are willing to learn relativity's answer. Otherwise this forum is the proper place, but I suggest you create a new thread]

This thread is in a strange state.. Ram1024 seems content with Hurkyl's answers, even though I suggested there were a misunderstanding between them, Ram1024 doesn't try to clarify and Hurkyl doesn't try to investigate.. On the other hand I don't want more time wasted, so I don't mind if this thread dies.

 

[ram1024]

well i can't really disprove SR if it's giving answers that i deem to be "correct" :D

the whole idea for this was to try and point out a paradox of reference frames using simultaneity of one observer (which i believe to be immutable)

maybe if Tom can chime in and dispute Hurkyl's answers we can try again.

 

[wespe]

well i can't really disprove SR if it's giving answers that i deem to be "correct" :D

I see problems, ram1024:
You don't know enough about SR to find the answers yourself. So you have to rely on others for those answers. Then you fail to specify the scenario clearly and you get different answers. One of the answers happen to match your version and you give up. You were trying to disprove a theory you don't know enough about in the first place. How will it be next time? Don't you see the problem, even after 100 replies I'm not sure what the scenario is anymore. Next time, don't omit "obvious" details, use some math if possible.

 

[ram1024]

well if SR wasn't so counter intuitive it'd be a lot easier for me to describe situations that can be easily viewed by it :|

SR contains too many things that go against what i believe to be reality, all to accommodate this "constant relative light speed".

i haven't given up

 

[wespe]

well if SR wasn't so counter intuitive it'd be a lot easier for me to describe situations that can be easily viewed by it :|

SR contains too many things that go against what i believe to be reality, all to accommodate this "constant relative light speed".

Exactly. All those counter intuitive things were invented to satisfy constant relative light speed. So, all you have to do is disprove constant relative light speed. Or, find an alternate theory that satisfies constant relative light speed. Good luck!

 

[ram1024]

constant relative itself makes no sense. that means it's not constant NOT relative. think about THAT one :D

 

[wespe]

constant relative itself makes no sense. that means it's not constant NOT relative. think about THAT one :D

Makes no sense? You have the option of disproving it. You should be able to explain how it was measured constant in experiments.

Yes, relative, but still constant. Speed is a ratio. Due to SR effects this ratio remains constant. Or, you could even say it's absolute, in the sense that all observers agree it's constant.

 

[ram1024]

but ONLY if you give all observers their own reality :|

 

[wespe]

but ONLY if you give all observers their own reality :|

All observers can have their own reality as long as these realities don't create a paradox. I kind of liked your idea about a common reality created by superimposing these individual realities (or sth like that). But that common reality is of no use to us mere mortals :)

 

[geistkiesel]

but ONLY if you give all observers their own reality :|

Ram: Some gross physics might help. When discussing a moving frame relative to a stationary frame or a frame < your frame there are practical limits. Trains and stationary platforms are a slam dunk open obvious. The train moves, the platform is a stationary platorm. Who is going to realistically sta3e that the platform can be considered moving while the train is stationar.? The train started in the stationary frame and it is that entity that is moviing. Because mathematics says you can do it doesn't mean you have to do it.

What about relative motion between two bodies. If there is a time acceleration history then the frames can be distinguished such that V(frame1) < V(frame2) and while the frames are inertial, constant velocity, one is always moving slower than the other even though the math let's you swap out the frames "because you can".

This is illogical to do it once much less more than once, but taking the digression v1>v2>v3>v4> to extremes, there has to be zero velocity as a lower limit. So why swap out frames, just because you can?
I suppose that c would be the max velocity until that barrier is overcome.

Your day is up, but ram1024 I think you won after all: can't you sense the anguish, the anticipated high pitched moans of panicked SR theorists, contemplating the demise of their cherished theory. ..?

 

[ram1024]

if i had some real experimental data to work with i could take it further.

or a better grounding in maths and the formulas used :(

what i had was logic, and it appears i come to the same conclusions that SR does. <shrug>

 

[ram1024]

albeit with a different system... so maybe i need to polish that :D

 

[ram1024]

on a different note, since SR confirms the same thing that i was thinking about "reality" that means my Spacebuoy HAS to work.

and now since civilians are making space flights, maybe i can sneak one of my spacebuoys on-board and prove an universal stationary relative frame :D

 

[HallsofIvy]

ram1024: What you "deem" to be correct is irrelevant to whether relativity is correct or not. The only thing that is relevant is the experimental evidence- which is strongly in favor of relativity.

By the way "logic" is useless without facts.

 

[ram1024]

if what i deem to be correct leads to the same results as relativity then i don't care, either way like i said before, my purposes are realized by them.

i think i'll port the space-buoy over to this thread since it's agreed that it will work now :D

 

[ram1024]

URF (Universal Rest Frame) Space-Buoy© <- ke ke
the machine consists OF:

1 heavy duty computing device
4 photon receptors
4 equal length long ass poles and 4 photon emitters connected to sychronized clocks
some thrusters for movement.

now the idea for this consists of detecting the difference in arrival times of the photons from different directions.

if the photons from any source arrive SOONER than other sources, we can conclude we are moving towards that emitter. we merely perform some calculations, use our thrusters to slow us down, and take another measurement.

when we finally receive the light from all sources at the same time we will be at complete universal rest, and objects functioning in this relativistic inertial frame will bear true space/time

 

[Hurkyl]

but ONLY if you give all observers their own reality

Reality, in SR, is worldlines living in space-time.

Observers don't have their "own reality"; they just measure reality differently.

 

[ram1024]

well ya, but "their measurement" are also perfectly valid, according to einstein assertions, so you they DO have their own reality :D

 

[ArmoSkater87]

ok...i read the first section of arguements, and jesus u all make it way more complicated than it really is. It might seem this way to me because I'm a high school student going into 12th grade, and i have yet to take BC calc and AP physics when school starts. Even though i can't go into the detail that u all go into all the frames and ****, but from the very biginning i saw that the answers were true, true, true. I'll come some time to see what else is up, well, have fun argueing about SR. By the way, u just can't try to disprove the theory of one of the greatest geniuses of all time, SR has been proven correct in several experiments. (-_-)