swansont Posted June 15, 2010 Posted June 15, 2010 Well, LT claims light is located at ( r(1+v/c,0,0) in the O frame when O and O'1 are co-located. This is because O'1 and O'2 are simultaneous and we have been through the math. So, if LT is logical then light is located at at ( r(1+v/c,0,0) when O and O'1 are co-located. But, based on the light postulate, light is only located (r,0,0) in O. How do you resolve this? O'1 and O'2 are simultaneous in the O' frame. Light is located at r(1+v/c) according to O'1 You have omitted the bolded statements. O1 and O'1 being co-located for a simultaneous event at that point does not convey simultaneity at any other point. Simultaneity is relative. How? This is wrong. The light cone is identical. The space-time coords are not. But, we have been through this. O'1 and O disagree on the light cone in terms of O'2. Can you show how they agree when they are co-located? No, this does not work. Observations are relative until two observers are at the same place. Observations of remote points are relative even if two observers are at the same place, but experience relative motion. Your understanding of light sphere and light cones is flawed (they are related, so the core misunderstanding is probably the same) If they are at the same place and disagree on the light sphere, then there must be more than one. Are you claiming the light sphere is relative? The light sphere is only a sphere in the rest coordinate system; c is constant in each frame. But the speed of light is not a constant relative to a moving object or frame. So there is a light sphere according to an observer in O, and there is a light sphere according to an observer in O'. They are not the same, because there is no absolute reference frame.
vuquta Posted June 16, 2010 Author Posted June 16, 2010 O'1 and O'2 are simultaneous in the O' frame. Light is located at r(1+v/c) according to O'1 You have omitted the bolded statements. O1 and O'1 being co-located for a simultaneous event at that point does not convey simultaneity at any other point. Simultaneity is relative. I am going to agree simultaneity is relative. However, we have already decided O cannot refute light is at r(1+v/c) in its coordinates or O refutes the light and relativity postulates in the O' frame. I think you are concluding O can simply ignore the simultaneity in O' and O cannot soi that without refuting SR. So, O cannot refute light is at r(1+v/c). But, that puts light at r and r(1+v/c). Note, none of this logic refutes the relativity of simultaneity. It just shows when the simutaneity of O' is overlayed with the R of S of O using the co-location of O'1 and O, then light is located at two frontiers of one coordinate system. Observations of remote points are relative even if two observers are at the same place, but experience relative motion. Your understanding of light sphere and light cones is flawed (they are related, so the core misunderstanding is probably the same) I do not think so. Observations of remote points are relative even if two observers are at the same place, but experience relative motion. How? Please explain this with two observers in relative motion at the same place. This would imply light behaves differently frame to frame contradicting the relativity postulate. The light sphere is only a sphere in the rest coordinate system; c is constant in each frame. But the speed of light is not a constant relative to a moving object or frame. So there is a light sphere according to an observer in O, and there is a light sphere according to an observer in O'. They are not the same, because there is no absolute reference frame. An absolute reference frame has nothing to do with this. The light postulate says light proceeds spherically from the light emission point in the frame. The conjunction of the light postulate and the relativity postulate says light proceeds spherically from the light emission point in the moving frame. So they are the same by the relativity postulate. The rules of physics are the same frame to frame.
swansont Posted June 17, 2010 Posted June 17, 2010 I do not think so. You're the one doing Lorentz transforms — math, and math only — and getting contradictory results. (The constancy of c within a frame is used to derive the transforms, so this does not add any information.) Explain how you can do a series of transforms and get them to disagree without making a mistake somewhere. Hint: it will be where you try and place a constraint that is not included in the transforms. Observations of remote points are relative even if two observers are at the same place, but experience relative motion. How? Please explain this with two observers in relative motion at the same place. This would imply light behaves differently frame to frame contradicting the relativity postulate. Light behaves the same in each frame — it travels at c. That's what the postulate says, and it leads to the Lorentz transformations. It does not hold true when you mix frames. An absolute reference frame has nothing to do with this. The light postulate says light proceeds spherically from the light emission point in the frame. The conjunction of the light postulate and the relativity postulate says light proceeds spherically from the light emission point in the moving frame. So they are the same by the relativity postulate. The rules of physics are the same frame to frame. The light postulate says light proceeds spherically from the light emission point in the frame according to an observer in that frame. The conjunction of the light postulate and the relativity postulate says light proceeds spherically from the light emission point in the moving frame according to an observer in that frame. These postulates do not say that you will see a sphere in the moving frame, when observed from the stationary frame. A light pulse emitted from the center of a train will hit the back wall first, according to an observer on the ground. According to an observer in the center of the train, it hits front and back at the same time. Even if the two observers are co-located when the train observer sees this. Your scenario is no different, other than the unnecessary added complications of doing it in two dimensions and having different sized circles.
vuquta Posted June 18, 2010 Author Posted June 18, 2010 You're the one doing Lorentz transforms — math, and math only — and getting contradictory results. (The constancy of c within a frame is used to derive the transforms, so this does not add any information.) Explain how you can do a series of transforms and get them to disagree without making a mistake somewhere. Hint: it will be where you try and place a constraint that is not included in the transforms. Let's see, I included only points in the domain of LT. I then applied the postulates of SR and no others. No, I did not include artificial constraints. Light behaves the same in each frame — it travels at c. That's what the postulate says, and it leads to the Lorentz transformations. It does not hold true when you mix frames. Can you explain why two observers at the same place in relative motion will draw different conclusions about one light sphere? If light is a constant c to both frames and the relativity postulate is true, then two observers at the same place should draw the same conclusions about one light sphere unless the relativity postulate is false. The light postulate says light proceeds spherically from the light emission point in the frame according to an observer in that frame. The conjunction of the light postulate and the relativity postulate says light proceeds spherically from the light emission point in the moving frame according to an observer in that frame. These postulates do not say that you will see a sphere in the moving frame, when observed from the stationary frame. A light pulse emitted from the center of a train will hit the back wall first, according to an observer on the ground. According to an observer in the center of the train, it hits front and back at the same time. Even if the two observers are co-located when the train observer sees this. If the two observers were on a light phone, each would contend light is proceeding spherically from the light emission point in the frame. Therefore, we cannot exclude this scientific evidence and this is consistent with SR. Hence, the O observer cannot refute light is at O'2 if it is at O'1 when O and O'1 are co-located. This places light at (r,0,0) and at (r(1+v/c),0,0) in the coordinates of the stationary frame. Can you take a position as to why this is false since that is what you are saying. Please derive your conclusions from the two postulates of SR.
swansont Posted June 18, 2010 Posted June 18, 2010 Let's see, I included only points in the domain of LT. I then applied the postulates of SR and no others. No, I did not include artificial constraints. The postulates of SR are included in the LT. There is no need to apply them separately. When you do, and do so incorrectly, you apply an artificial constraint. Can you explain why two observers at the same place in relative motion will draw different conclusions about one light sphere? If light is a constant c to both frames and the relativity postulate is true, then two observers at the same place should draw the same conclusions about one light sphere unless the relativity postulate is false. The observers will come to different conclusions because c is a constant in the stationary frame. Relative simultaneity is a consequence of this. There are two light spheres, one for each frame. The observers in each frame will not agree on where the light is. If you drew a circle in the O' frame, centered on the light pulse, the O observer will not see it as a circle, and would also not see light hit all the points simultaneously. Because it's moving — it gets distorted from length contraction, and the light is moving relative to it, so the light hits the point moving toward the source first. If the two observers were on a light phone, each would contend light is proceeding spherically from the light emission point in the frame. Therefore, we cannot exclude this scientific evidence and this is consistent with SR. This isn't evidence, since it's not a physical experiment. It's trivially easy to simply describe a situation that is physically impossible. Which is why the only way to falsify a prediction is with a physical experiment. The observers see a sphere in their own frame. They do not see a sphere in the other frame. Hence, the O observer cannot refute light is at O'2 if it is at O'1 when O and O'1 are co-located. O does not see this. O cannot "refute" it because observations are relative, but O will not agree that it is true. This places light at (r,0,0) and at (r(1+v/c),0,0) in the coordinates of the stationary frame. Can you take a position as to why this is false since that is what you are saying. Please derive your conclusions from the two postulates of SR. This places light at (r,0,0) and at (r(1+v/c),0,0) in the coordinates of the stationary frame according to two different observers, and there is nothing in SR that says that these two observers must agree. The light is at r(1+v/c) in O coordinates, but it's due to the O' observer. Where the light is depends on the observer. This doesn't magically change because you've used one set of coordinates instead of the other. It's still the same observer.
vuquta Posted June 18, 2010 Author Posted June 18, 2010 (edited) The postulates of SR are included in the LT. There is no need to apply them separately. When you do, and do so incorrectly, you apply an artificial constraint. Well, I did not apply the postulates incorrectly. If you think I dfid, please be specific as to how. Further, you have not refuted any conclusions along the way. If you think you have, please apply the postulates to prove the refutation. The observers will come to different conclusions because c is a constant in the stationary frame. Relative simultaneity is a consequence of this. There are two light spheres, one for each frame. The observers in each frame will not agree on where the light is. If you drew a circle in the O' frame, centered on the light pulse, the O observer will not see it as a circle, and would also not see light hit all the points simultaneously. Because it's moving — it gets distorted from length contraction, and the light is moving relative to it, so the light hits the point moving toward the source first. I am afraid this is completely wrong. Light emerges spherically from the light emission point in the stationary frame. By the relativity postulate and the light postulate, light emerges spherically from the light emission point in the moving frame. Either observer is seeing a perfect light sphere at the origin under SR regardless of the motion of the light source. So, there is no such thing as an SR observer seeing a non-sphere as light. This isn't evidence, since it's not a physical experiment. It's trivially easy to simply describe a situation that is physically impossible. Which is why the only way to falsify a prediction is with a physical experiment. Actually it is evidence. It is a physical model that cannot be satisified by SR of which LT and SR are supposed to map any light event correctly. It is impossible for SR to describe this physical situation without a mathematical contradiction. For example, do you need to do an experiment to show 1 ≠ 0? The observers see a sphere in their own frame. They do not see a sphere in the other frame. I am OK with this statement. But, this does not resolve the fact that SR calculates two different light positions in the stationary system of coordinates when O and O'1 are co-located. By the relativity postulate, O cannot refute the conclusion and LT calculation of the O' frame which places light at a different position than does the O frame all in the coords of O when O and O'1 are co-located. O does not see this. O cannot "refute" it because observations are relative, but O will not agree that it is true. This places light at (r,0,0) and at (r(1+v/c),0,0) in the coordinates of the stationary frame according to two different observers, and there is nothing in SR that says that these two observers must agree. The light is at r(1+v/c) in O coordinates, but it's due to the O' observer. The reason light is located at two different place and now you agree, is because of the LT calculation of O'1. Further, this places light more specifically at (r,0,0) and at (r(1+v/c),0,0) when O and O'1 are co-located. LT is supposed to correctly map from the O' observers to the O observer. Obviously, it does not. Edited June 18, 2010 by vuquta
swansont Posted June 19, 2010 Posted June 19, 2010 Well, I did not apply the postulates incorrectly. If you think I dfid, please be specific as to how. Further, you have not refuted any conclusions along the way. If you think you have, please apply the postulates to prove the refutation. You haven't been paying attention then. Go back and reread. I am afraid this is completely wrong. Light emerges spherically from the light emission point in the stationary frame. By the relativity postulate and the light postulate, light emerges spherically from the light emission point in the moving frame. Either observer is seeing a perfect light sphere at the origin under SR regardless of the motion of the light source. So, there is no such thing as an SR observer seeing a non-sphere as light. Go back and reread what I wrote. I said a circle drawn in a frame will not be seen as a circle in the other frame. If you want to express the coordinates as a circle (or sphere), you have to use your own frame. Actually it is evidence. It is a physical model that cannot be satisified by SR of which LT and SR are supposed to map any light event correctly. It is impossible for SR to describe this physical situation without a mathematical contradiction. For example, do you need to do an experiment to show 1 ≠ 0? No, you don't have to do an experiment for that, since it's math. And what you've done is the equivalent of showing 1 = 0 or 1 = 2, i.e. a contradiction. Which always involves an illegal step. I am OK with this statement. But, this does not resolve the fact that SR calculates two different light positions in the stationary system of coordinates when O and O'1 are co-located. SR calculates two positions, one for each observer. There is nothing in SR to imply that this is a problem. It is the whole concept of relativity, that an observation is relative to the observer. To imply otherwise is to misunderstand relativity. By the relativity postulate, O cannot refute the conclusion and LT calculation of the O' frame which places light at a different position than does the O frame all in the coords of O when O and O'1 are co-located. And this is not a problem. It is what SR predicts. The reason light is located at two different place and now you agree, is because of the LT calculation of O'1. Further, this places light more specifically at (r,0,0) and at (r(1+v/c),0,0) when O and O'1 are co-located. LT is supposed to correctly map from the O' observers to the O observer. Obviously, it does not. Light is not in two different places; this statement makes no sense — one always has to attribute an observation to an observer. That is your misunderstanding of what the calculations show. The observer in O calculates one location, regardless of which coordinate system it is expressed in. The observer in O' calculates a different location, regardless of which coordinate system it is expressed in. No one observer sees the light in two places.
vuquta Posted June 19, 2010 Author Posted June 19, 2010 You haven't been paying attention then. Go back and reread. Go back and reread what I wrote. I said a circle drawn in a frame will not be seen as a circle in the other frame. If you want to express the coordinates as a circle (or sphere), you have to use your own frame. You have not explained why SR arrives at two different conclusions for the position of the light sphere in one coordinate system when O and O'1 are co-located. This implies the theory cannot decide on the proper location. You cannot use a preferred frame so you must accept both answers. Let me give you a simple comparison. Where is the car when it reaches an observer. It is at a distance 80 miles and it is at a distance 60 miles. No, you don't have to do an experiment for that, since it's math. And what you've done is the equivalent of showing 1 = 0 or 1 = 2, i.e. a contradiction. Which always involves an illegal step. You have not refuted that light is a distance r ( 1 + v/c ) and a distance r in the coords of O when O and O'1 are co-located. v ≠ 0 v/c ≠ 0 1 + v/c ≠ 1 r ( 1 + v/c ) ≠ r So, we do not have an illegal step yet light can only be at one place with two observers at the same place. Yet, SR claims it is at two different places. Yes, each frame has its circle. That is the problem. That implies light must be at two different places when O and O'1 are at the same place. This is the part you have not justified under SR. But, you can prove this is you can prove v = 0. Otherwise, it is false. SR calculates two positions, one for each observer. There is nothing in SR to imply that this is a problem. It is the whole concept of relativity, that an observation is relative to the observer. To imply otherwise is to misunderstand relativity. Do not forget, the observers are at the same place. Also, if light is at two different locations and you already confessed O cannot refute O'1, then light is at r ( 1 + v/c). Now, since r/c elapsed in the O frame and O cannot refute light is at r ( 1 + v/c) then then speed of that light is r ( 1 + v/c)/(r/c) = ( c + v ). This refutes the light postulate in the stationary frame. Any ray of light moves in the ``stationary'' system of co-ordinates with the determined velocity c, whether the ray be emitted by a stationary or by a moving body. http://www.fourmilab.ch/etexts/einstein/specrel/www/ Light is not in two different places; this statement makes no sense — one always has to attribute an observation to an observer. That is your misunderstanding of what the calculations show. The observer in O calculates one location, regardless of which coordinate system it is expressed in. The observer in O' calculates a different location, regardless of which coordinate system it is expressed in. No one observer sees the light in two places. It is the case that reality says light cannot be seen at two different locations but you are confusing reality with SR. Let's review what you have confessed. This places light at (r,0,0) and at (r(1+v/c),0,0) in the coordinates of the stationary frame according to two different observers, and there is nothing in SR that says that these two observers must agree. The light is at r(1+v/c) in O coordinates, but it's due to the O' observer. And you are wrong about this statement. The observer in O calculates one location, regardless of which coordinate system it is expressed in. This is completely false. O calculates a location in its own system. Any other system will assign different coordinates to this location. That is SR. But, LT is supposed to be bijective and hence, there should be no disagreement of the location of the light sphere. With this exercise, we see that there is. If there is a disagreement on the location of the light sphere, then O will have to measure this light at a different speed contradicting the light postulate.
Cap'n Refsmmat Posted June 19, 2010 Posted June 19, 2010 Do not forget, the observers are at the same place. That doesn't mean they're in the same reference frame, does it?
vuquta Posted June 19, 2010 Author Posted June 19, 2010 That doesn't mean they're in the same reference frame, does it? Nope, they are not in the same frame. But, that are at the same place. Under SR, how can two observers at the same place disagree on the position of the light sphere in one coordinate system given light is a universal constant c for both frames. Light must be at the same place for these two observers in some chosen coordinate system. If it is not, then the rules of physics are different for the two frames.
Cap'n Refsmmat Posted June 19, 2010 Posted June 19, 2010 Why? One's moving. It undergoes length contraction. Surely the distances it measures from its frame would be different than the distances the other observer measures, because of length contraction, at the least. Right?
swansont Posted June 19, 2010 Posted June 19, 2010 Nope, they are not in the same frame. But, that are at the same place. Under SR, how can two observers at the same place disagree on the position of the light sphere in one coordinate system given light is a universal constant c for both frames. Light must be at the same place for these two observers in some chosen coordinate system. If it is not, then the rules of physics are different for the two frames. No, this is not true.
vuquta Posted June 19, 2010 Author Posted June 19, 2010 Why? One's moving. It undergoes length contraction. Surely the distances it measures from its frame would be different than the distances the other observer measures, because of length contraction, at the least. Right? I am sure under SR length contraction does apply when viewing a moving frame's metrics. Two things. 1) The is the relativity postulate: the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good. http://www.fourmilab.ch/etexts/einstein/specrel/www/ Hence, both frames must be viewing a spherical light wave and not one length contracted since the behavior of light is independent of the motion of the light source. 2) I mapped the position of O'2 using LT back into the stationary system of coords. LT is supposed to compensate for length contraction. Merged post follows: Consecutive posts mergedOriginally Posted by vuquta Nope, they are not in the same frame. But, that are at the same place. Under SR, how can two observers at the same place disagree on the position of the light sphere in one coordinate system given light is a universal constant c for both frames. Light must be at the same place for these two observers in some chosen coordinate system. If it is not, then the rules of physics are different for the two frames. No, this is not true. On which part do you disagree?
swansont Posted June 19, 2010 Posted June 19, 2010 I am sure under SR length contraction does apply when viewing a moving frame's metrics. Two things. 1) The is the relativity postulate: the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good. http://www.fourmilab.ch/etexts/einstein/specrel/www/ Hence, both frames must be viewing a spherical light wave and not one length contracted since the behavior of light is independent of the motion of the light source. O'1 sees light at O'2, but the location of O'2 is length contracted according to O while the light is not. So the light is not at the location of O'2, and it doesn't matter which coordinate system you use to express the location of O'2. 2) I mapped the position of O'2 using LT back into the stationary system of coords. LT is supposed to compensate for length contraction. Again, O'2's location is length contracted, while the light's is not. Hence, they are not co-located according to O. On which part do you disagree? "Light must be at the same place for these two observers in some chosen coordinate system" is false, because the observers are not in the same frame of reference.
vuquta Posted June 19, 2010 Author Posted June 19, 2010 O'1 sees light at O'2, but the location of O'2 is length contracted according to O while the light is not. So the light is not at the location of O'2, and it doesn't matter which coordinate system you use to express the location of O'2. I have the length contraction argument convered as well. Since O'2 is located at (r/γ,0,0), then O views the distance as length contracted and hence, O'2 is located at (r/γ²,0,0) in the coords of O. Since the light sphere is r from the light emission point in O, then t = r/c. Since O'2 is moving relative to O, then O'2 is located at vt + r/γ² = vr/c + r/γ². It must now be shown vr/c + r/γ² > r and then O'2 is still further down the positive x-axis making the speed of light ≠ c for the light that hits O'2. c > v vc > v² vc + c² > v² + c² vc + c² - v² > c² (vc + c² - v²)/c² > 1 vc/c² + (c² - v²)/c² > 1 v/c + 1/γ² > 1 vr/c + r/γ² > r Hence, since O'2 is further than (r,0,0), then the speed of light that hit O'2 when O and O'1 are co-located > c. "Light must be at the same place for these two observers in some chosen coordinate system" is false, because the observers are not in the same frame of reference. It does not matter whether they are in the same frame of reference. You can use length contraction and/or LT to convert one frame's coordinates into the others in order to standardize. If you cannot convert one fram'es coords into the other's then LT is false and hence SR is false. Further, if light is not at the same place in the coords of O and neither can be refuted, then I am OK with that. But, that implies light traveled further to strike O'2 than did the light that hit (r,0,0) in time t=r/c in the time of O. This implies the light is faster than c that hit O'2 in the coordinates of O. So, if we refute that light hit O'2 when O and O'1 are co-located, then we refute the relativity postulate. If we agree light hit O'2 when O and O'1 are co-located, then no matter how you calculate, LT or length contaction, O'2 is located further than (r,0,0) in the stationary system of coordinates. Hence, the light hit O'2 in time t=r/c is faster than c which contradicts the light postulate since it traveled further than (r,0,0) in time t=r/c. The light postulate says: Any ray of light moves in the ``stationary'' system of co-ordinates with the determined velocity c http://www.fourmilab.ch/etexts/einstein/specrel/www/
swansont Posted June 19, 2010 Posted June 19, 2010 I have the length contraction argument convered as well. Since O'2 is located at (r/γ,0,0), then O views the distance as length contracted and hence, O'2 is located at (r/γ²,0,0) in the coords of O. Since the light sphere is r from the light emission point in O, then t = r/c. Since O'2 is moving relative to O, then O'2 is located at vt + r/γ² = vr/c + r/γ². It must now be shown vr/c + r/γ² > r and then O'2 is still further down the positive x-axis making the speed of light ≠ c for the light that hits O'2. c > v vc > v² vc + c² > v² + c² vc + c² - v² > c² (vc + c² - v²)/c² > 1 vc/c² + (c² - v²)/c² > 1 v/c + 1/γ² > 1 vr/c + r/γ² > r Hence, since O'2 is further than (r,0,0), then the speed of light that hit O'2 when O and O'1 are co-located > c. You have assumed the light hits O'2 when O and O'1 are co-located, by using the time when light hits O. As you have shown, this can only happen if light travels faster than c. If you solve this properly, you will find that, according to O, the light hits O'2 after it hits O'1 It does not matter whether they are in the same frame of reference. You can use length contraction and/or LT to convert one frame's coordinates into the others in order to standardize. If you cannot convert one fram'es coords into the other's then LT is false and hence SR is false. Yes, it does matter what frame they are in, in terms of what they observe. You have transformed the coordinates of O'2. That's not in dispute. But you have assumed that the light strike occurs simultaneously in both frames, and you can't just assume this. Further, if light is not at the same place in the coords of O and neither can be refuted, then I am OK with that. But, that implies light traveled further to strike O'2 than did the light that hit (r,0,0) in time t=r/c in the time of O. Again, this analysis ASSUMES that the strikes are simultaneous in both frames. Which is a poor assumption, and we know this because it leads to a contradiction. This implies the light is faster than c that hit O'2 in the coordinates of O. So, if we refute that light hit O'2 when O and O'1 are co-located, then we refute the relativity postulate. If we agree light hit O'2 when O and O'1 are co-located, then no matter how you calculate, LT or length contaction, O'2 is located further than (r,0,0) in the stationary system of coordinates. Hence, the light hit O'2 in time t=r/c is faster than c which contradicts the light postulate since it traveled further than (r,0,0) in time t=r/c. Once again, we cannot assume the light strikes are simultaneous, so we don't agree on this. It is not true, and you have not arrived at that via any principle of special relativity.
vuquta Posted June 19, 2010 Author Posted June 19, 2010 You have assumed the light hits O'2 when O and O'1 are co-located, by using the time when light hits O. As you have shown, this can only happen if light travels faster than c. If you solve this properly, you will find that, according to O, the light hits O'2 after it hits O'1 OK, according to O, light hits O'2 after co-location. But, according to O'1, light hits O'2 when O and O'1 are co-located. Are you now refuting this SR conclusion? Why does SR make two completly different claims for one light sphere? Yes, it does matter what frame they are in, in terms of what they observe. You have transformed the coordinates of O'2. That's not in dispute. But you have assumed that the light strike occurs simultaneously in both frames, and you can't just assume this. I did not assume anything about the light strikes being simultaneous. I dont care one way or the other. I simply pointed out the fact there is no way to satisfy both postulates in this example. If there is simply be specific as to how this can be done. Again, this analysis ASSUMES that the strikes are simultaneous in both frames. Which is a poor assumption, and we know this because it leads to a contradiction. We also know if they are not simultaneous in both it leads to a contradiction as well. That is what we have been doing here. We have been assuming they are not simultaneous frame to frame and arriving at contradictions.
swansont Posted June 19, 2010 Posted June 19, 2010 OK, according to O, light hits O'2 after co-location. But, according to O'1, light hits O'2 when O and O'1 are co-located. Are you now refuting this SR conclusion? Why does SR make two completly different claims for one light sphere? I am not refuting this, it is what I have been saying all along. The claims are different because the observers are in two different frames of reference. Each frame will have its own observation. I did not assume anything about the light strikes being simultaneous. I dont care one way or the other. I simply pointed out the fact there is no way to satisfy both postulates in this example. If there is simply be specific as to how this can be done. The way you misapplied the postulate made them simultaneous. The constancy of the speed of light applies only in the "stationary" frame, as you have quoted. Any ray of light moves in the ``stationary'' system of co-ordinates with the determined velocity c The speed of light will not appear as a constant relative to the moving frame. We also know if they are not simultaneous in both it leads to a contradiction as well. That is what we have been doing here. We have been assuming they are not simultaneous frame to frame and arriving at contradictions. You have never solved this without applying absolute simultaneity, i.e. stating that O sees light strike O'1 and O'2 at the same time, or assuming light moves at c relative to the moving frame.
vuquta Posted June 19, 2010 Author Posted June 19, 2010 I am not refuting this, it is what I have been saying all along. The claims are different because the observers are in two different frames of reference. Each frame will have its own observation. We are talking LT concluding one position for light in the coords of O and O concluding something different. You are wrong in your statement. This is not an observer issue This is an SR issue. One part of SR concludes light will not be at O'2 and another part concludes it will be at O'2. So, instead of using observers, use the logic of SR as I am. The way you misapplied the postulate made them simultaneous. The constancy of the speed of light applies only in the "stationary" frame, as you have quoted. Yes, and I produced a light wave in the stationary frame given to me by LT that proves the speed of light > c. Are you refuting LT? The speed of light will not appear as a constant relative to the moving frame. What???? You have never solved this without applying absolute simultaneity, i.e. stating that O sees light strike O'1 and O'2 at the same time, or assuming light moves at c relative to the moving frame. Nope I never have applied absolute simultaneity. Like I said I do not care. I am not an aether person. I applied SR and showed if absolute simultaneity is true then SR is false. Also, if absolute simultaneity is false, then SR is false. Are you able to resolve this without refuting one of the postulates. I have already asked you this. I already know you cannot.
swansont Posted June 20, 2010 Posted June 20, 2010 We are talking LT concluding one position for light in the coords of O and O concluding something different. You are wrong in your statement. This is not an observer issue This is an SR issue. One part of SR concludes light will not be at O'2 and another part concludes it will be at O'2. So, instead of using observers, use the logic of SR as I am. As long as you continue to think that this is not an observer issue, you will fail to understand relativity. The crux of the issue is that observations are relative to the frame of the observer. It is insufficient to have observers co-located in order to know what they see. You have to know what frame of reference they are in, because that is what determines what they see.
vuquta Posted June 20, 2010 Author Posted June 20, 2010 As long as you continue to think that this is not an observer issue, you will fail to understand relativity. The crux of the issue is that observations are relative to the frame of the observer. It is insufficient to have observers co-located in order to know what they see. You have to know what frame of reference they are in, because that is what determines what they see. The purpose of the co-location is to set the timing between the frames. Thus, when O and O'1 are co-located, in the stationary frame, SR says light is located at (r,0,0). At the co-location of O and O'1, the primed frame asserts light is at O'2. Then, you convert the location of O'2 into the coordinates of the O frame and you find light located further down the x-axis in the O coords than is (r,0,0) forcing the light that hit O'2 to be faster than the light that hit (r,0,0). What I did is eliminate SR's relative time arguments to analyze its true conclusions by creating this co-location. We find a contradiction to the light postulate in the stationary frame with regard to O'2 since O cannot refute light hit O'2 at the co-location without refuting SR. You have agreed O and O'1 are co-located based on the setup. You have agreed when O and O'1 are co-located, (r,0,0) is hit with the light. You have agreed when O and O'1 are co-located, O'2 is hit with the light. You have agreed O'2 is further down the x-axis than (r,0,0) by any possible calculation under SR. You have also agreed this places one light sphere at two completely different positions in one coordinate system when O and O'1 are co-located. You have not disagreed the light that hits O'2 must be faster than the light that hits (r,0,0). Everything stated above is according to the rules of SR. The last thing you said I believe is that an observer can view two different light speeds in it own coordinates. I posted the light postulate to refute that position. Any ray of light moves in the ``stationary'' system of co-ordinates with the determined velocity c, whether the ray be emitted by a stationary or by a moving body. http://www.fourmilab.ch/etexts/einstein/specrel/www/ Note, the light postulate does not allow for multiple speeds of light in the stationary system of coordinates.
swansont Posted June 20, 2010 Posted June 20, 2010 The purpose of the co-location is to set the timing between the frames. Thus, when O and O'1 are co-located, in the stationary frame, SR says light is located at (r,0,0). At the co-location of O and O'1, the primed frame asserts light is at O'2. Then, you convert the location of O'2 into the coordinates of the O frame and you find light located further down the x-axis in the O coords than is (r,0,0) forcing the light that hit O'2 to be faster than the light that hit (r,0,0). What I did is eliminate SR's relative time arguments to analyze its true conclusions by creating this co-location. You can't do this. You are ignoring the time component, which essentially means you are assuming they are simultaneous. According to O, light hasn't arrived at O'2 when it arrives at O'1. They don't happen at the same time, so you can't ignore the timing, eliminate the timing, or make any assumptions about the timing. Transforming the spatial coordinates does not mean you have changed who is making the observation. We find a contradiction to the light postulate in the stationary frame with regard to O'2 since O cannot refute light hit O'2 at the co-location without refuting SR. No, the contradiction is in your assumption that the light hits O'2 at the same time it hits O'1, according to an observer in the O frame. You have agreed O and O'1 are co-located based on the setup. You have agreed when O and O'1 are co-located, (r,0,0) is hit with the light. You have agreed when O and O'1 are co-located, O'2 is hit with the light. You have agreed O'2 is further down the x-axis than (r,0,0) by any possible calculation under SR. You have also agreed this places one light sphere at two completely different positions in one coordinate system when O and O'1 are co-located. You have not disagreed the light that hits O'2 must be faster than the light that hits (r,0,0). Everything stated above is according to the rules of SR. No, what you have stated is not true, and not in accordance with SR. I have agreed when O and O'1 are co-located, (r,0,0) is hit with the light according to O. I have agreed when O and O'1 are co-located, O'2 is hit with the light according to O'. I have agreed O'2 is further down the x-axis than (r,0,0) when light hits it according to O. Exactly as the calculation under SR says. I have not agreed this places one light sphere at two completely different positions in one coordinate system when O and O'1 are co-located. I do agree that such a statement is nonsensical, because it does not refer to a reference frame. I have not agreed the light that hits O'2 must be faster than the light that hits (r,0,0). Your statements are wrong, in part, because you do not state which for observer it is supposed to hold. The ordering of events is not true for all observers, and you cannot make a blanket statement about what happens when and where. You can onlymake the statement according to a specific observer. Observations are relative to the frame of reference of the observer. The last thing you said I believe is that an observer can view two different light speeds in it own coordinates. I posted the light postulate to refute that position. Any ray of light moves in the ``stationary'' system of co-ordinates with the determined velocity c, whether the ray be emitted by a stationary or by a moving body. http://www.fourmilab.ch/etexts/einstein/specrel/www/ Note, the light postulate does not allow for multiple speeds of light in the stationary system of coordinates. Once again, you have misunderstood what I said, as evidenced by completely reversing it when you repeat it. I invite you to go back and reread my posts. Light speed is constant in the stationary frame. This means you measure c relative to items at rest in that frame. That's what stationary means. It means not moving. Moving things are not in the stationary frame. Only stationary things are in the stationary frame. Notice how the postulate doesn't mention moving items or moving frames. That means you can make no claim about getting c when you measure the speed relative to a moving frame. The postulate does not tell you this.
vuquta Posted June 20, 2010 Author Posted June 20, 2010 You can't do this. You are ignoring the time component, which essentially means you are assuming they are simultaneous. According to O, light hasn't arrived at O'2 when it arrives at O'1. They don't happen at the same time, so you can't ignore the timing, eliminate the timing, or make any assumptions about the timing. I can ignore time. The co-location is at a point in time and not an interval. Are you now arguing O and O'1 are not co-located? Well, they are and I showed that. This strategy allows me to calculate everything based on the co-location of the two. The, based on the relativity postulate, i.e. the rules of physics are the same from both frames, I calculate everything at that common instant, which is different times on the two clocks, using the rules of SR. Since SR must apply at all times in any frame, I am on solid footing. According to O, light hasn't arrived at O'2 when it arrives at O'1. They don't happen at the same time, so you can't ignore the timing, eliminate the timing, or make any assumptions about the timing Yes, this is correct for O since the light is located at (r,0,0). But, according to the SR postulates in O', light is in fact located at O'2 when the two are co-located. You have already agreed light is at O'2 when the two are co-located. Otherwise, SR is false in O'. Hence, light is located at both positions under the rules of SR. Transforming the spatial coordinates does not mean you have changed who is making the observation. This suggests you are refuting LT. LT is suppsed to transform coordinates regardless of the existence of observers. If you refute LT, then you refute SR. So, this does not apply. No, the contradiction is in your assumption that the light hits O'2 at the same time it hits O'1, according to an observer in the O frame. This is SR. If light strikes O'1 and O'1 and O'2 are equidistant from the light emission point in the frame, then by the light postulate in the O' frame, light is at O'2. So, this is not my assumption, this is SR's I guess you are refuting the light postulate. I have agreed when O and O'1 are co-located, (r,0,0) is hit with the light according to O.I have agreed when O and O'1 are co-located, O'2 is hit with the light according to O'. I have agreed O'2 is further down the x-axis than (r,0,0) when light hits it according to O. Exactly as the calculation under SR says. OK, all the above we are in agreement. I have not agreed this places one light sphere at two completely different positions in one coordinate system when O and O'1 are co-located. I do agree that such a statement is nonsensical, because it does not refer to a reference frame. OK, have you used LT before? If light strikes a point in a frame, then LT is used to transform this into another frame which I did. All I did was apply the rules of SR using LT. Can you explain why you believe either LT is nonsensical or my application of LT is nonsensical? In physics, the Lorentz transformation, named after the Dutch physicist Hendrik Lorentz, describes how, according to the theory of special relativity, two observers' varying measurements of space and time can be converted into each other's frames of reference. It reflects the surprising fact that observers moving at different velocities may measure different distances, elapsed times, and even different orderings of events. http://en.wikipedia.org/wiki/Lorentz_transformation I have not agreed the light that hits O'2 must be faster than the light that hits (r,0,0). Perhaps you can indicate the location of the O'2 observer in the O frame when O and O'1 are co-located. Your statements are wrong, in part, because you do not state which for observer it is supposed to hold. The ordering of events is not true for all observers, and you cannot make a blanket statement about what happens when and where. You can onlymake the statement according to a specific observer. I agree the ordering of events can be different frame to frame under SR. My statements are not really my statements, they are the postulates of SR. I apply the postulates in the O frame when O and O'1 are co-located and then I apply the postulates in the O' frame when O and O'1. I find that forces light to hit O'2 at the co-location. I then apply LT to O'2 to map it into the O frame. So, the use of LT allows frame to frame mapping or observer to observer mapping. Observations are relative to the frame of reference of the observer. Yes and then LT is used to convert these observations into the context of other frames. Light speed is constant in the stationary frame. This means you measure c relative to items at rest in that frame. That's what stationary means. It means not moving. Moving things are not in the stationary frame. Only stationary things are in the stationary frame. Notice how the postulate doesn't mention moving items or moving frames. That means you can make no claim about getting c when you measure the speed relative to a moving frame. The postulate does not tell you this. I brought the coordinate of O'2 into the stationary frame using LT. Light is at O'2 and hence it is r(1+v/c) in the stationary frame when O and O'1 are co-located. What should be happening here in case you do not know is that when O and O'1 are co-located, if LT worked properly, then O'2 should map to (r,0,0). Well, this is not what is happening. Again, O cannot refute light is at O'2 which is r(1+v/c) when O and O'1 are co-located. Otherwise, light hits O'2 at co-location and also after co-location which implies two light spheres in the view of the O frame.
swansont Posted June 20, 2010 Posted June 20, 2010 I can ignore time. The co-location is at a point in time and not an interval. Are you now arguing O and O'1 are not co-located? Well, they are and I showed that. This strategy allows me to calculate everything based on the co-location of the two. The, based on the relativity postulate, i.e. the rules of physics are the same from both frames, I calculate everything at that common instant, which is different times on the two clocks, using the rules of SR. Since SR must apply at all times in any frame, I am on solid footing. It is a time interval; the common event that starts all of this is the light emission, not the co-location. By ignoring the time effects, you are tacitly assuming absolute simultaneity. Which is what I've been telling you for several pages now. I don't know how else to explain that you're wrong.
vuquta Posted June 20, 2010 Author Posted June 20, 2010 It is a time interval; the common event that starts all of this is the light emission, not the co-location. By ignoring the time effects, you are tacitly assuming absolute simultaneity. Which is what I've been telling you for several pages now. I don't know how else to explain that you're wrong. No, this is wrong. 1) Absolute simultaneity would conclude light is located at (r,0,0) in the context of both frames or light is located at (r(1+v/c,0,0) in both frames. 2) The co-location is a common point in time where everything under SR should calculate correct inside both frame and mapped with LT back and forth between the frames. Though the clock readings are different for the frames at co-location, there can be no dispute they are co-located. 3) SR should be consistent with its conclusions at this co-location of the frames. So, I am not depending on absolute simultaneity, in fact I am depending that SR calls this false. This is how I am able to force SR to confess light is located at (r,0,0) and also located at (r(1+v/c,0,0) when O and O'1 are co-located. Now, if you are somehow calling the co-location of O and O'1 some kind of absolute simultaneity, then you will need to take that up with SR because that is what SR concludes. Specifically, what rule of SR are you claiming I am violating, the light postulate, the relativity postulate or LT? Oh, did you ever say where O'2 is located in the coords of O when O and O'1 are co-located?
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