xyzt Posted September 17, 2014 Posted September 17, 2014 Very good arguments! I will try them next time you say something else than "nope". Well, I explained earlier, in great detail why your fringe ideas are wrong. No point in repeating the explanation, it doesn't take in your case.
studiot Posted September 17, 2014 Posted September 17, 2014 If you do a real experiment, how can you be sure that the two flashes of light are simultaneous if you do not have a precise clock at each end of the train? Did Einstein have a clock specified in his train experiment? Please point me to the reference.
christopherkirkreves Posted September 17, 2014 Author Posted September 17, 2014 To xytz: Okay. ------- To studio: “since information cannot travel faster than c” This is a true statement, and a proposition that I’ve run into many times in the past when I was trying to turn the logic of this theory back in on itself and into a “paradox.” However, this factor does not come into play when examining either the “Two Lightning Bolt Strikes” thought experiment or the “One Light Bulb On a Moving Car” thought experiment. So, I agree. “Firstly the lightning event is a chance event and by chance, happens just right for the experiment. Secondly matters can be confirmed at leisure post event.That is both the positions of the observers and strikes can be measured subsequently.” Yep. It is a stipulation of this thought experiment that the two lightning bolt strikes occur at the same time. No problem. “Now ask yourself where does the lightning come from?” If the “Two Lightning Bolt Strikes” thought experiment works, it should also work if we replace the “lightning bolt strikes” with “light bulbs.” And we can then say that there are two light bulbs that are resting alongside the train tracks, and they are an equal distance from both men when they are in position with one another, and we can stipulate that the two light bulbs flash at the same time. I think what leads to much confusion with this thought experiment has to do with lightning bolts striking points along the embankment. This gives the reader the sense that the flashes of light are then more connected to the inertial frame of reference of the embankment than the inertial frame of reference of the train. But they are not. If the motion (or lack of motion) of the emanating source of light is irrelevant to the velocity of light, then it does not matter that the flashes of light come from lightning striking points along the embankment that happen to be at rest (in the inertial frame of reference of the embankment) relative to the man on the embankment. This thought experiment (if it works) should also work if there are two men out in free space and two light bulbs also out in free space. One of the men is at rest relative to the two light bulbs, and the other man is moving (relativity) towards one light bulb and away (relativity) from the other. From the odd man’s perspective it is the two light bulbs and the other guy that is moving. And, then, if we stipulate that the two light bulbs flash at the same time (which I believe we can do in a thought experiment) then the odd man will see the two flashes of light simultaneously. The two light bulbs are an equal distance from him at the time of the flashes and so the flashes of light (from his perspective of being at rest) travel over equal distances at equal velocities. Their motion (relative to him) at the time of the flashes is irrelevant. And so (to finally get around and answer your question) the lightning bolts are in the inertial frame of reference of the embankment, and the lightning bolt strikes occur in the inertial frame of reference of the embankment, and the emanating sources of the two flashes of light (the two points of impact) are in the inertial frame of reference of the embankment. “Does it come from a universe moving alongside the train?” Yes, from the perspective of the train at rest. “Or does it come from the universe where the track is sited?” I’m not sure what this means. The track is at rest relative to the embankment. The tracks and the embankment are in the same inertial frame of reference. The man in the train moving along the tracks is in a different inertial frame of reference. “Or does it come from another universe altogether?” There is only one universe in this thought experiment. And in that universe there are two different inertial frames of reference: the embankment and the train. And in this thought experiment the lightning bolts and the strikes all are in and all occur in the inertial frame of reference of the embankment. “Using that answer I can explain Einstein's train experiment to you.” Cool. Thank you. ---------- To pzkpfw: “That setup and stipulations are no different really (in the sense of setupishness and stipulationity) than the Einstein version. The setup by comstock ensures the flashes are simultaneous in the car frame, and shows they won't be for the bystander. Einstein sets up the embankment frame to have simultaneous flashes and shows they won't be simultaneous for the other observer.” I disagree. In Comstock’s thought experiment the setup “ensures” the flashes are simultaneous in the car and “ensures” the flashes are simultaneous for the bystander. For the man on the road the one flash of light travels a shorter distance and the other flash of light travels a longer distance. And so, if as stipulated, both flashes of light travel, for the man on the road, at equal velocities, the one flash of light must reach the rear of the car first and the other flash of light must reach the front of the car later. There is no difference, in Comstock’s thought experiment, between the “thinking” going into the analysis for the man on the road and the man in the car; there is not an “ensuring” and then a “showing.” The difference does not come from two different kinds of analysis, but in the fact that the two men are in two different situations in specifically whether the two flashes of light travel equal or unequal distances. For the man where the two flashes of light travel equal distances, then they reach the front and the rear of the car at the same time. And for the man where the two flashes of light travel unequal distances, then they reach the front and the rear of the car one before the other. In Einstein’s “Two Lightning Bolt Strikes” thought experiment, both men are in equal positions to see the two flashes of light simultaneously. When Einstein says (on page 30) “Now in reality (considered with reference to the railway embankment) he [the man on the train] is hastening towards the beam of light coming from B, whilst he is riding on ahead of the beam of light coming from A” I see this not as him stipulating that the two flashes are simultaneous for the man on the embankment and therefore also logic dictates that sense the man on the train will be in a different position than the man on the embankment when the flashes of light reach him he therefore must see one before the other, but rather as Einstein making the mistake of thinking that it is the man on the train who is actually “in motion” and that the flashes of light are somehow “in” or “more connected to” the inertial frame of reference of the embankment. But I think your reading of this (and your different reading of this than mine) is justifiable. When Einstein says “now in reality … he is hastening towards … [and] … riding ahead” I see this as a clear sign that Einstein is thinking that the man on the train is the one “actually in motion.” If I understand your interpretation of this quote correctly then “now in reality … he is hastening towards … [and] … riding ahead” means “if we stipulate that the man on the embankment will see the two flashes of light simultaneously, then from the perspective of the embankment at rest it is the man on the train who is in motion, and so we can then say he is in motion, we can talk about him as being in motion, and we can then also stipulate or logically conclude that he must see the one flash of light before the other.” Einstein certain doesn’t directly say this, and, I think, it’s a bit too much to read all of this into his words. Even if I’m wrong, I hope you will agree that it is at least plausible to read Einstein’s argument as one in which he makes the mistake of believing that it is the man on the train who is “actually in motion.” And a simple reading of the text, I believe, points to not the more complicated reading into his words but to the fact that he just so happened to make a mistake. We all do. “Comstock set it up so the flashes will be simultaneous in the car frame, by placing the bulb in the centre of the car. Einstein stipulates the strikes to be simultaneous in the embankment frame. It's basically the same thing. The real point is - what now is the situation for the other frame?” Again, I disagree. Einstein says the two lightning bolt strikes occur at the same time. This means they could reach the man in the train simultaneously. In Comstock’s thought experiment there is no possibility for the man on the road to see the two flashes of light reach the front and the rear of the car simultaneously. Comstock’s thought experiment proves “events which are simultaneous in one inertial frame of reference are not simultaneous in another.” Comstock proves the RoS (as you guys like to abbreviate it). In Einstein’s thought experiment both the man in the train and the man on the embankment are equally positioned to see the two flashes of light simultaneously. You have made the argument that if the one man sees the two flashes of light simultaneously then logically the other man cannot (and you have made the argument that Einstein is also making this argument). And I disagree. I think that in the “Two Lighting Bolt Strikes” thought experiment, since each man is justified in thinking that he is at rest, then, given how this thought experiment is set up, both the man on the train and the man on the embankment will see the two flashes of light simultaneously. (Again, we are discussing a thought experiment here and not whether or not the real world works this way.) And, even if I’m wrong, I hope you will agree that I am, at least, making a plausible argument. I hope you will agree that given how Einstein set up his “Two Lightning Bolt Strikes” thought experiment that it is not totally irrational to think that it leads to both men seeing the two flashes of light at the same time (in the world of thought experiments). And, if you agree that I’m not being totally and completely irrational in what I think his thought experiment leads to, then I think you will have to agree that Einstein’s and Comstock’s thought experiment are not equally valid, because I would argue (and I think you would agree with me) that for someone to conclude that in Comstock’s thought experiment both the man on the road and the man in the car can (or might or may) see the two flashes of light simultaneously is totally and completely irrational. Yes? No? “Aside from you seeming to contradict yourself (because the end result is the same but you claim different interpretations) that's where the Comstock experiment falls down, it doesn't show the reciprical nature of the relativity of simultaneity very well.” When Einstein says “… and vice versa (relativity of simultaneity) …” again you and I disagree. I do not think that he is saying because it could be the man on the train or the man on the embankment who sees the two flashes of light simultaneously this demonstrates the reciprocal nature of simultaneity but I think he is just asserting the reciprocal nature of simultaneity because that can be logically deduced. If Einstein’s thought experiment works and (my interpretation of what he is claiming) it proves that the man on the embankment will see the two flashes of light simultaneously and the man in the train will see the one before the other, then the same thing could be done with two lightning bolts coming from two clouds in the train striking two point in the train, and so the same logic (if his logic is right, and in my interpretation of his logic) will show, if we were to do the thought experiment in the inverse, that the man on the train will see the two flashes of light simultaneously while the man on the embankment will see the one before the other. In the same way Comstock’s thought experiment does not set out to show the reciprocal nature of simultaneity but it easily deduced. Simply move the light bulb out of the car and place it on the road. You will set the same result (with the two flashes of light hitting two points along the road) at the same time for the man on the road and one before the other for the man in the car. Comstock does not directly mention the reciprocal nature of simultaneity but it only a hop, skip, and a jump away and I’m sure he would have said “yeah.” “I really don't see why you are so hung up on that claimed "ambiguity".” Yep. We may be reaching a point of “agreeing to disagree.” To me it is totally clear that the two thought experiments are different, and one is weaker, and one is most likely wrong (unless other things are read into it), and one is ambiguous in a way that the other is not. I do respect your thinking. And so perhaps we just need to agree to disagree and end it here. “Einstein does that better by having both of his observers equidistant from the strikes.” Right. I’m sure in 1916 Einstein was away of Comstock’s 1910 thought experiment, and I think Einstein probably thought that his was the better of the two thought experiments because his thought experiment does not rely on clocks and Comstock’s necessary does (and two different sets of two clocks in the two different inertial frames of reference). “Simultaneity” is defined differently in Comstock’s and Einstein’s thought experiments and Einstein called his definition “… the most natural definition of simultaneity ….” I agree with you that Einstein’s thought experiment has its advantages … if it worked. But I don’t think it works. And you and I have been round and round this disagree of ours again and again. “Given you seem to accept Comstocks result, why do you phrase this as "that occurred at the same time" without reference to which frame they occured at the same time in?” “Well, that's basically getting to be metaphysical rubbish. Strikes are either going to be simultaneous in a frame or not. There's no "God power" involved in looking at a case where two strikes were simultaneous in one frame and figuring out whether they were in another. No more than Comstock is "God" with his light bulb placement.” In Einstein’s thought experiment he says that the two flashes of light occur at the same time and they do so when they are an equal distance from the two men. This thought experiment concludes (proves) that “events which are simultaneous in one inertial frame of reference are not in another.” If we don’t take this conclusion as also its premise then when examining this thought experiment “pre conclusion” it does not matter what inertial frame of reference these lightning bolt strikes come from. If we say, no, it does matter which frame of reference these lightning bolt strikes come from because “events which are simultaneous in one inertial frame of reference are not simultaneous in another” must be taken into account when determining whether or not in this thought experiment the man on the embankment and/or the man on the train will see the two flashes of light simultaneously or not, is then to use the conclusion of this thought experiment as one of its premises and this is circular logic. When using Comstock’s thought experiment there is no need to use the conclusion of the thought experiment, “events which are simultaneous in one inertial frame of reference are not simultaneous in another,” as a premise in order to prove that “events which are simultaneous in one inertial frame of reference are not simultaneous in another.” And so, if we are not using this as a premise, and if both men in Einstein’s thought experiment as it is set up are equally positioned to see the two flashes of light simultaneously, then if we are going to make the argument that, no, both men will not see the two flashes of light simultaneously but rather only one will and then we will logically reason that the other man will not, then, when analyzing Einstein’s thought experiment we are playing “God” is choosing one man over the other (and so would have to be the case in the real physical world). Now, if you saying that in this thought experiment we are not playing “God” in choosing one man over the other because the two lightning bolt strikes occurred in the inertial frame of reference of the embankment and so he will see them simultaneously, then I think you are making the same mistake as Einstein. The motion or lack of motion of the emanating sources of the flashes of light (the points of impact) is irrelevant. And once those flashes of light are in motion they are no more connected to the inertial frame of reference of the embankment than they are to the inertial frame of reference of the train. And if all we have done is stipulate that they occurred at the same time, then the man on the train is equally positioned to see them simultaneously and so to say one man or the other is the one who sees them simultaneously (and then argue that logic dictates then so the other man does not) is to become “metaphorically nonsensical” but to actually do this. “You continue to assume that simultaneous events must be simultaneous in all frames.” I assume this because before this thought experiment reaches its conclusion we have no reason to think otherwise. All we know at this point is what Einstein has stipulated and assumed. And before we reach the conclusion of this thought experiment he has stipulated that the two flashes of light occur at the same time. And so, without any reason to believe otherwise, yes, it is assumed that they are simultaneous for everyone. It is only after he reaches his conclusion of this thought experiment and proves (or believes he proves) that “events which are simultaneous in one inertial frame of reference are not simultaneous in another and therefore every inertial frame of reference has its own particular time” that we can then start talking about different inertial frames of references with events not being simultaneous in both and, in more general, different inertial frames of reference each having their own particular time (as is then assumed by the Lorentz transformations, which follow RoS). Again, in Comstock’s thought experiment the conclusion does not need to be assumed as a premise. ---- To swansont: “owing to length contraction” On page 30 of his book Einstein concludes: “We thus arrive at the important result: Events which are simultaneous with reference to the embankment are not simultaneous with respect to the train …” And he does this without a single reference to “length contraction” (or “time dilation” or the math of the Lorentz transformations). It is clear that Einstein believes he has proven this without reference to “length contraction.” And, I would argue (I have argued) that to use “length contraction” when analyzing this thought experiment, which is a ramification of the Lorentz transformations and the Lorentz transformations assume “every inertial frame of reference has its own particular time,” which is also the conclusion of this thought experiment, is to then engage in circular logic. I believe Einstein’s “Two Lightning Bolt Strikes” thought experiment must stand on itself own and apart from the rest of the theory which assumes “every inertial frame of reference has its own particular time” in order to prove that “every inertial frame of reference has its own particular time.” ------- To Dekan: “If we can work out the answers by doing "Thought Experiments" , why bother with any actual physical tests?” Thought experiments are useful, but so are empirical test. They are different. And while a thought experiment may be correct in the sense that given its premises it proves what it purports to prove its always possible that the premises are wrong or that the actual physical world is counterintuitive and so while the reasoning is right the world still doesn’t work that way. And To Janus: Yep. --------- To studiot: “This thread is going nowhere at approximately 0.99999999999c because no one seems to want to stick to the point and complete discussion of the first proposed 'experiment', rather prefering to introduce alternative experiments. Comstocks experiment or Einsteins? I could just as easily observe that Einstein introduced the formula E = mc2 in 1905, some 24 years after JJ Thompson introduced the formula E = 0.75melmc2” Yep. ----------- To Le Repteux: Maybe someday. --------- Thank you all. Cheers! - Christopher
studiot Posted September 17, 2014 Posted September 17, 2014 (edited) If the “Two Lightning Bolt Strikes” thought experiment works, it should also work if we replace the “lightning bolt strikes” with “light bulbs.” No, No and no again. Why do you insist on changing Einstein's stipulations? Any fool can change the experiment so that it fails. So what. And why do you not want to hear (follow) the logic behind what Einstein actually specified? And why do you not want to answer the simple question I asked you as to the location of the source of the lightning? Edited September 17, 2014 by studiot
Le Repteux Posted September 17, 2014 Posted September 17, 2014 I bet Chris does not answer you because Einstein did not talk about other universes in his mind experiment. Do as you ask others to do Studiot, stick to Einstein's specifications!
studiot Posted September 17, 2014 Posted September 17, 2014 (edited) I bet Chris does not answer you because Einstein did not talk about other universes in his mind experiment. Do as you ask others to do Studiot, stick to Einstein's specifications! I did but I used the word universe to avoid the word frame. You are still dodging the question What is the location of the source of the lightning? The answer to this is all important. Edited September 17, 2014 by studiot
pzkpfw Posted September 17, 2014 Posted September 17, 2014 (edited) ... In Einstein’s “Two Lightning Bolt Strikes” thought experiment, both men are in equal positions to see the two flashes of light simultaneously. ... If the flashes of light were simultaneous in their frame. And you are assuming they are simultaneous in both frames. ... When Einstein says (on page 30) “Now in reality (considered with reference to the railway embankment) he [the man on the train] is hastening towards the beam of light coming from B, whilst he is riding on ahead of the beam of light coming from A” I see this not as him stipulating that the two flashes are simultaneous for the man on the embankment and therefore also logic dictates that sense the man on the train will be in a different position than the man on the embankment when the flashes of light reach him he therefore must see one before the other, ... Neither do I. He stipulates elsewhere that the flashes are simultaneous for the embankment observer. Here, he is showing how they can't be simultaneous for the train observer. Note how Einstein is very careful to always note which frame he is talking in reference to: "... (considered with reference to the railway embankment) ...". ... but rather as Einstein making the mistake of thinking that it is the man on the train who is actually “in motion” and that the flashes of light are somehow “in” or “more connected to” the inertial frame of reference of the embankment. But I think your reading of this (and your different reading of this than mine) is justifiable. There's no mistake. Each observer is entitled to think of themselves as at rest and the other as in motion. If talking from the point of view of the embankment there's no mistake to consider the train as moving. And Einstein makes no such assertion as you claim here. The flashes are in no way "in" or "more connected to" the embankment frame. When Einstein says “now in reality … he is hastening towards … [and] … riding ahead” I see this as a clear sign that Einstein is thinking that the man on the train is the one “actually in motion.” If I understand your interpretation of this quote correctly then “now in reality … he is hastening towards … [and] … riding ahead” means “if we stipulate that the man on the embankment will see the two flashes of light simultaneously, then from the perspective of the embankment at rest it is the man on the train who is in motion, and so we can then say he is in motion, we can talk about him as being in motion, and we can then also stipulate or logically conclude that he must see the one flash of light before the other.” Einstein certain doesn’t directly say this, and, I think, it’s a bit too much to read all of this into his words. Sorry, but I think your interpretation is very poor. I think you are tryting to hard to get to some conclusion you prefer. Even if I’m wrong, I hope you will agree that it is at least plausible to read Einstein’s argument as one in which he makes the mistake of believing that it is the man on the train who is “actually in motion.” And a simple reading of the text, I believe, points to not the more complicated reading into his words but to the fact that he just so happened to make a mistake. We all do. No. 1916 was nearly a hundred years ago. I really don't think you've stumbled on some mistake that 98 years of science has missed. (Yes, Argumentum ad populum is a fallacy). Einstein says the two lightning bolt strikes occur at the same time. This means they could reach the man in the train simultaneously. ... You've said this so many times I wonder if you are purposely being obstuse. He wrote: "Are two events (e.g. the two strokes of lightning A and B) which are simultaneous with reference to [ 31 ] the railway embankment also simultaneous relatively to the train?". You keep ommitting the "with reference to", implying that it's assumed the simultaenity is absolute. You have made the argument that if the one man sees the two flashes of light simultaneously then logically the other man cannot (and you have made the argument that Einstein is also making this argument). And I disagree. I think that in the “Two Lighting Bolt Strikes” thought experiment, since each man is justified in thinking that he is at rest, then, given how this thought experiment is set up, both the man on the train and the man on the embankment will see the two flashes of light simultaneously. (Again, we are discussing a thought experiment here and not whether or not the real world works this way.) Only, if simultaenity is absolute, and that if two events are simultaneous in one frame they are simultaneous in all frames. If you assume that, not only are assuming the result you want (and in disagreement with Comstoicks result) but you are invalidating the postulates of SR. And, even if I’m wrong, I hope you will agree that I am, at least, making a plausible argument. I hope you will agree that given how Einstein set up his “Two Lightning Bolt Strikes” thought experiment that it is not totally irrational to think that it leads to both men seeing the two flashes of light at the same time (in the world of thought experiments). And, if you agree that I’m not being totally and completely irrational in what I think his thought experiment leads to, then I think you will have to agree that Einstein’s and Comstock’s thought experiment are not equally valid, because I would argue (and I think you would agree with me) that for someone to conclude that in Comstock’s thought experiment both the man on the road and the man in the car can (or might or may) see the two flashes of light simultaneously is totally and completely irrational. No. Sorry, you are deliberately missing the point in too many ways; I do not see your interpretation of Einstein as rational. When Einstein says “… and vice versa (relativity of simultaneity) …” again you and I disagree. I do not think that he is saying because it could be the man on the train or the man on the embankment who sees the two flashes of light simultaneously this demonstrates the reciprocal nature of simultaneity but I think he is just asserting the reciprocal nature of simultaneity because that can be logically deduced. If Einstein’s thought experiment works and (my interpretation of what he is claiming) it proves that the man on the embankment will see the two flashes of light simultaneously and the man in the train will see the one before the other, then the same thing could be done with two lightning bolts coming from two clouds in the train striking two point in the train, and so the same logic (if his logic is right, and in my interpretation of his logic) will show, if we were to do the thought experiment in the inverse, that the man on the train will see the two flashes of light simultaneously while the man on the embankment will see the one before the other. That's way off in two ways. The first is you'll get a contradiction in reality. An observer can't both see the flashes at the same time and not see them at the same time. But that's the situation you are trying to create. Secondly, you stubbornly refuse to let go of the idea that simultaenity is absolute - even though you accept Comstocks result! Vice versa here means that events simultaneous in the train frame can't be in the embankment frame. They would of course have to be different events than two events that are simultaneous in the embankment frame. See the paragraph above. In the same way Comstock’s thought experiment does not set out to show the reciprocal nature of simultaneity but it easily deduced. Simply move the light bulb out of the car and place it on the road. You will set the same result (with the two flashes of light hitting two points along the road) at the same time for the man on the road and one before the other for the man in the car. Comstock does not directly mention the reciprocal nature of simultaneity but it only a hop, skip, and a jump away and I’m sure he would have said “yeah.” You're not far off here. I don't understand why you can't extend that idea. ... In Einstein’s thought experiment he says that the two flashes of light occur at the same time and they do so when they are an equal distance from the two men. ... NO HE DOESN'T! See above. Until you let go of this, you won't understand the experiment, and you'll continue to need your "playing God" view. Edited September 17, 2014 by pzkpfw
swansont Posted September 18, 2014 Posted September 18, 2014 To swansont: “owing to length contraction” On page 30 of his book Einstein concludes: “We thus arrive at the important result: Events which are simultaneous with reference to the embankment are not simultaneous with respect to the train …” And he does this without a single reference to “length contraction” (or “time dilation” or the math of the Lorentz transformations). It is clear that Einstein believes he has proven this without reference to “length contraction.” And, I would argue (I have argued) that to use “length contraction” when analyzing this thought experiment, which is a ramification of the Lorentz transformations and the Lorentz transformations assume “every inertial frame of reference has its own particular time,” which is also the conclusion of this thought experiment, is to then engage in circular logic. I believe Einstein’s “Two Lightning Bolt Strikes” thought experiment must stand on itself own and apart from the rest of the theory which assumes “every inertial frame of reference has its own particular time” in order to prove that “every inertial frame of reference has its own particular time.” I'm sorry, I thought the goal here was for you to understand the situation, and to show that you were wrong. “every inertial frame of reference has its own particular time” is an implication of relativity, not some separate assumption; there is no "rest of the theory" that you can separate from this. Time and space are relative, and that means simultaneity is as well. The train example is just that, an example, showing the ramifications of relativity. It's not a proof; assuming that relativity is correct is the proper way to work an example of the ramifications of relativity. The "proof" of relativity lies in experiment, and only in experiment. The theoretical part tells you the foundation and what the predictions are.
christopherkirkreves Posted September 18, 2014 Author Posted September 18, 2014 If I may, let me restate my original position, but now with all of the comments, questions, and issues that have arisen in this thread in mind. One I believe that the Lorentz transformations are based on the relativity of simultaneity, because: 1. That is how Einstein does in fact construct his theory in his book “Relativity: The Special and General Theory.” (He works through the “Two Lightning Bolt Strikes” thought experiment, comes to its conclusion, and then moves onto the Lorentz transformations.) 2. This is how Einstein says he has constructed his theory in his paper “The Foundation of the General Theory of Relativity.” 3. And, the counterintuitive assumption of the Lorentz transformations (“every inertial frame of reference has its own particular time”) is justified by being the conclusion of the “Two Lightning Bolt Strikes” thought experiment. To believe that the Lorentz transformations are not based on the relativity of simultaneity, is to believe: 1. In his book he just randomly decides to talk about the relativity of simultaneity just before the Lorentz transformations. 2. In his paper his either misspeaks or there is some other interpretation of the meaning of “… there follow, in the well-known way, the relativity of simultaneity, the Lorentzian transformations …” than the plain meaning of the text. 3. And he lays out the Lorentz transformation with an unjustified counterintuitive assumption which could be justified it he had constructed his theory with the Lorentz transformations based on the relativity of simultaneity. Two The statement “events which are simultaneous in one inertial frame of reference are not simultaneous in another” is counterintuitive. It may seem intuitive to you 100 years post the Theory of Relativity. But, in the early 1900’s it was definitely counterintuitive and could not simply be asserted but rather had to be argued for and demonstrated. It had to be justified. I believe that if the statement “events which are simultaneous in one inertial frame of reference are not simultaneous in another” is not a premise of the “Two Lightning Bolt Strikes” thought experiment, then the “Two Lightning Bolt Strikes” thought experiment does not work. Einstein says the two men are both equal distances from the two flashes of light at the time of their occurrences. And Einstein stipulates that the two flashes of light occur at the same time. And then you will say to me “You say that they occur ‘at the same time’ but you don’t say in what inertial frame of reference.” And then I will say “At this point in this thought experiment the concept ‘events which are simultaneous in one inertial frame of reference are not simultaneous in another’ has not been established yet, and so even though the events do occur, as stipulated by Einstein, in the inertial frame of reference of the embankment, this is not relevant. The way a man (or woman) in the early 1900’s would have understood the idea ‘at the same time’ would simply be the common sense idea that they occurred ‘at the same time’ without any need to reference inertial frames of reference. It is once Einstein establishes ‘events which are simultaneous in one inertial frame of reference’ that he then logically deduces ‘every inertial frame of reference has its own particular time.’ At this point in this thought experiment neither of these two ideas have been established yet. It is the purpose of this thought experiment to establish this, and so, by definition, this has not yet been established at the start of the thought experiment.” And then you will say to me “You don’t understand what you are talking about.” And then I will say “Okay let us agree to disagree.” I believe Einstein does not take “events which are simultaneous in one inertial frame of reference are not simultaneous in another and therefore every inertial frame of reference has its own particular time” as a premise of this thought experiment. There is no place in his text where he says he is doing this. I believe he is laying out his thought experiment with the early 1900 common sense understanding of “at the same time” which, at this point in the construction of his theory, does not include “every inertial frame of reference has its own particular time.” And so, if he is doing what I believe he is doing, with the two flashes of light occurring at the same time and at equal distances from the man on the embankment and traveling at equal velocities to the man on the embankment, the man on the embankment will see the two flashes of light at the same time. And so, if he is doing what I believe he is doing, with the two flashes of light occurring at the same time and at equal distances from the man on the train and traveling at equal velocities to the man on the train, the man on the train will see the two flashes of light at the same time. And so, the conclusion “events which are simultaneous in one inertial frame of reference are not simultaneous in another” does not follow. The thought experiment, if Einstein is doing what I believe he is doing, does not work. Now, if he is using “events which are simultaneous in one inertial frame of reference are not simultaneous in other” as a premise of this thought experiment, then it does work. However, this then means using the conclusion of this thought experiment as its premise. And I do not believe that Einstein used the conclusion of his thought experiment as its premise. And, lastly, it has been suggested in this thread that Einstein does not use his conclusion as his premise but rather that Einstein says that “the two flashes of light will either be simultaneous for the man on the train or for the man on the embankment, and I, Einstein, assert that if one man sees them simultaneous then it then logically deduced that the other man will see one before the other.” There is no point in this text where he says this is his argument. There is no point in this text where he implies this is his argument. To say that this is what Einstein is saying is, I believe, to read into his words something that is not there. The closest you can get to arguably finding him saying this is in the statement “We thus arrive at the important result: Events which are simultaneous with reference to the embankment are not simultaneous with respect to the train and vice versa (relativity of simultaneity.” (pp. 30 – 31). But this particular statement is, these particular set of words make up, the conclusion of the “Two Lightning Bolt Strikes” thought experiment. If Einstein is making the argument that “the two flashes of light will either be simultaneous for the man on the train or for the man on the embankment, and I, Einstein, assert that if one man sees them simultaneous then it then logically deduced that the other man will see one before the other” why would he only make this argument (if he is making this argument) in the latter half of his conclusory statement and in most obscure langue where it has to be read in that this argument is there (if it is there)? If Einstein is making the argument that “the two flashes of light will either be simultaneous for the man on the train or for the man on the embankment, and I, Einstein, assert that if one man sees them simultaneous then it then logically deduced that the other man will see one before the other” then this is pretty central to his overall argument and you would think he would take the time (as he does will all of the other various aspects of the “Two Lightning Bolt Strikes” thought experiment) to make this explicit (or even somewhat more implicit). And so, I do not believe he is making this argument. I believe this is reading in too much into his words and it is not there. When Einstein says “Now in reality (considered with reference to the railway embankment) he [the man on the train] is hastening towards the beam of light coming from B, whilst he is riding on ahead of the beam of light coming from A” I believe he is saying what he is saying. I believe he is saying that the man on the train is in motion towards the one beam of light and is in motion away from the other beam of light. I don’t see him saying “from the perspective of the embankment at rest it appears that the man on the train is moving towards one flash of light and it appears that that the man on the train is moving away from the other flash of light.” I see him saying that it is the embankment that is actually at rest (“Now in reality”) and the man on the train who is actually in motion. Now you could say “no, this is the language, ‘Now in reality (considered with reference to the railway embankment),’ where we can read in that Einstein is making the argument ‘the two flashes of light will either be simultaneous for the man on the train or for the man on the embankment, and I, Einstein, assert that if one man sees them simultaneous then it then logically deduced that the other man will see one before the other.’” And I suppose I can see how you can see him saying “the two flashes of light will either be simultaneous for the man on the train or for the man on the embankment,” but the latter half of that argument “and I, Einstein, assert that if one man sees them simultaneous then it then logically deduced that the other man will see one before the other,” I believe, can in no way be read into this language here. I believe he is saying what he is saying. He is saying that the man on the embankment is the one actually at rest and he is saying that it is the man on the train who is actually in motion. He says “Now in reality (considered with reference to the railway embankment) he [the man on the train] is hastening towards the beam of light coming from B, whilst he is riding on ahead of the beam of light coming from A.” He is saying that physically (in the sense of a thought experiment) the two flashes of light are moving towards the man on the embankment and physically (in the sense of a thought experiment) the man on the train is moving towards one flash of light while moving away from the other flash of light (while they also move towards him). He is not saying this only appears to be happening from the perspective of the embankment at rest. He is saying, these are his words, no reading in alternative meanings necessary, “he is hastening towards” and “he is riding on ahead.” To say that Einstein is saying that the man in the train “is moving” in these two phrases is to use alternative words but is in keeping with the plain meaning of the plain language and is not to read in an alternative meaning. However, what this means is, if (as it has been suggested in this thread) that Einstein stipulates for which person the two flashes of light are simultaneous (and in this case he just happens to choose the person on the embankment) and then by logical deduction the other man must see the one flash of light before the other, then by stipulating for which man the two flashes of light are simultaneous, this then becomes a test of absolute rest, because the other man does not just appear to be in motion from the perspective of man stipulated to see the two flashes of light simultaneous (and so also, by implication, is stipulated to be “at rest”) but rather “Now in reality…” “… he is hastening towards …” and “… he is riding on ahead …,” in other words he is the one actually physically moving (in the sense of a thought experiment) towards one beam of light and away from the other while the other man is the one actually physically at rest and having the two flashes of light move towards him. This is a test of absolute rest. If this is what Einstein is intentionally proposing (which I do not believe he is) then he has proposed a test of absolute rest. I simply think he made a mistake. I believe he was just accidentally thinking in terms of the man in the train as actually in motion and the man on the embankment as actually at rest, not consciously, but because the two flashes of light kind of seem to be “in” the inertial frame of reference of the embankment and “less connected” to the inertial frame of reference of the train. If Einstein is making the argument (which I do not believe he is) “the two flashes of light will either be simultaneous for the man on the train or for the man on the embankment, and I, Einstein, assert that if one man sees them simultaneous then it then logically deduced that the other man will see one before the other” then along with his statements of “hastening towards” and “riding on ahead,” which explicitly indicate actual physical movement (in the sense of a thought experiment), then he is saying by stipulating which man sees the two flashes light simultaneously we have established absolute rest and who is actually in motion. Three In Comstock’s thought experiment (the “One Light Bulb On A Moving Car” thought experiment, there is no need to assume the conclusion (“events which are simultaneous in one inertial frame of reference are not simultaneous in another”), there is no need to read in additional arguments into what he plainly says, there is no need to stipulate who sees the two flashes of light simultaneously and who does not (the man in the car will see them reach the front and the rear of the car simultaneously and the man on the road will see the one reach the rear of the car first and then the other reach the front of the car later), there is no need for the mathematics of the Lorentz transformations or its ramifications of “length contraction” and “time dilation” (all of which assumes the relativity of simultaneity and so becomes circular), and there is no chance that Comstock, unlike Einstein, unwittingly proposed a test of absolute rest. I believe, given the four axioms, Comstock’s thought experiment works and proves (in the sense of a thought experiment) “events which are simultaneous in one inertial frame of reference are not simultaneous in another” from which it can then be logically deduced “every inertial frame of reference has its own particular time” which is then the justification for this as an assumption of the Lorentz transformations, while, I believe, Einstein’s thought experiment does not. And that is the restatement of my initial position based on the issues and ideas that have come up in this thread. Thank you. ----- To studiot: I thought I did answer all of your questions. The two lightning bolt strikes occur in the inertial frame of reference of the embankment. The two clouds (not explicitly mentioned but that can assumed to be there) are in the inertial frame of reference of the embankment. The two bursts of lighting that make their way from the two clouds to the two points along the embankment are in the inertial frame of reference of the embankment. The two point of impact along the embankment are in the inertial frame of reference of the embankment. And when the two flashes of light from the strikes then leave the points of impact and head towards the two men, they are moving away from two points that are in the inertial frame of reference of the embankment. However, I believe that this is all irrelevant. I believe that the motion of lack of motion of emanating sources of the light (the points of impact), which are at rest relative the man on the embankment and are in motion relative to the man on the train, is irrelevant. If the two lightning bolt strikes occurred “at the same time” then even though the sources of those flashes of light are in motion relative to the man on the train is irrelevant and so he will see the two flashes of light at the same time. And, I believe, that just because the emanating sources of these flashes of light are in the inertial frame of reference of the man on the embankment and not in the inertial frame of reference of the man on the train does not make these flashes of light (moving through the vacuum of space, as stipulated) “in” the inertial frame of reference of the embankment or somehow “more connect” to the man on the embankment than to the man on the train. And in terms of changing the thought experiment, there are, in every thought experiment, essential and nonessential elements. For example, the walls of the train are not essential. And, in fact, I believe they are harmful in these sense that they can be misleading. What makes two different inertial frames of references is relative motion and not physical barriers. And so, if I’m right and the walls of the train are not essential, then Einstein’s thought experiment could be changed so that the man is riding on a skateboard down a side walk and not inside a train. The logic should work the same. It’s relative motion that is essential and not the train walls. And in the same way, the embankment, I believe is irrelevant. What matters is that the two sources of light are in the same inertial frame of reference as one man and in a different inertial frame of reference as another man (and the two men both happen to be the same distance from the two flashes of light at the time they occur). I also think that the embankment while not only not essential to this thought experiment is also misleading. By having lightning bolts strike two point along the embankment it gives the impression that the two flashes of light are “in” and “connected to” the inertial frame of reference of the embankment. And they are not. The sources of these flashes of light are, but not the flashes of light themselves. And so I think using two light bulbs in free space to analysis the logic is better. It strips away, what I believe is, some of the misleading elements of this thought experiment. ---------- To pzkpfw: “And you are assuming they are simultaneous in both frames.” Yes. This thought experiment establishes that “events which are simultaneous in one inertial frame of reference are not simultaneous in another” and so when Einstein says the two lightning bolt strikes occur “at the same time” the conclusion of this thought experiment has not yet been demonstrated and so there is no reason to assume that if they “occur at the same time” that this would not be the case from the perspective of all inertial frames of reference. It hasn’t been established yet. That is what this thought experiment purports to establish at the end, in its conclusion. “He stipulates elsewhere that the flashes are simultaneous for the embankment observer.” Cool. Where? I have no problem admitted when I’m wrong. (I don’t like to be wrong, but I have no problem admitted it.) I have been over and over this theory for many years. You have just made the claim that he stipulates that the two flashes of light are simultaneous for the embankment observer somewhere else. Where? “If talking from the point of view of the embankment there's no mistake to consider the train as moving.” Except for the fact that if the train does not merely appear to be moving from the perspective of the embankment but is in fact physically in motion then this becomes a test of absolute rest. And it cannot be “mere appearance.” The man on the train must physically actually move towards one flash of light and he must physically actually move away from the other flash of light in order to encounter (perceive) the one flash of light before the other. And so, if two flashes of light being simultaneous in one inertial frame of references mean another body in another inertial frame of reference must actually be physically towards one flash of light and must actually be physically moving away from the other flash of light (which he must be doing if he is not to see the two flashes of light simultaneously in his own inertial frame of reference) then this is most definitely a test of absolute rest. “Sorry, but I think your interpretation is very poor. I think you are tryting to hard to get to some conclusion you prefer.” I cannot see how “hasting towards” and “riding on ahead” are not statements of “motion.” And by saying “Now in reality” he is also saying that the man in the train is actually physically moving towards one source of light and actually physically moving away from the other source of light. I believe that that is the plain meaning of the language and not something I’m reading into his words. “I really don't think you've stumbled on some mistake that 98 years of science has missed.” I’m not the only one. I’ve seen two essays on the internet where two other guys have figured out the same thing. And there was also a posting in a forum where a guy said “hey, I figured out a test for absolute rest” and then used Einstein’s thought experiment. (He was, then, subsequently shouted down and no one realized, what I believe, was that he had found Einstein mistake, but then made the mistake of not realizing it was a mistake.) And, a few years ago, I sent this argument to a guy with a Ph.D. who specialization is Relativity. I had sent him several of my “paradoxes.” He enjoyed them. And he was able to show me why I was wrong over and over again. And then, I decided to send him my argument about why the “Two Lightning Bolt Strikes” thought experiment was wrong. He essentially conceded the argument and said something to the effect of “that’s why I use the other thought experiment” and then essentially brushed this off as no big deal. (Which, of course, we disagreed about whether it was or was not a big deal.) And so, no, I am not the only one who has noticed his. And my guess is back in the days before the internet, over the last 100 years, there have been guys and gals here and there who have noticed this, and then for whatever reason (perhaps because they thought it was not big deal) just let it go. “(and in disagreement with Comstoicks result)” Comstock’s thought experiment concludes “events which are simultaneous in one inertial frame of reference are not simultaneous in another. Comstock’s thought experiment does not take as a premise “events which are simultaneous in one inertial frame of reference are not simultaneous in another.” The physical (in the sense of a thought experiment) set up of Comstock’s thought experiment, and given the four initial axioms, logically leads to “events which are simultaneous in one inertial frame of reference are not simultaneous in another.” This does not need to be stipulated to in order to then also reach this as the conclusion. “I do not see your interpretation of Einstein as rational” And if we’ve reached this point, then we really need to part ways. If we’ve reached this point then we probably cannot even “agree to disagree.” “"playing God" view.” I should never have mentioned “God.” I’m sorry. That was a mistake. What I was trying to say is that if both observers are equally positioned to see the two flashes of light simultaneously, but it must be stipulated who sees them simultaneously, then in the thought experiment, by being the one who gets to make that decision one is, in a sense, “playing God.” It is too loaded of a word. And I should not have used. And, besides, I was using it in a context where I now think I misunderstood you position. I thought you were saying both men were equally positioned to see the two flashes of light simultaneously and so we must stipulate who sees the two flashes of light simultaneously (“playing God). But now I think you’re saying something different. I now think your saying something more like “it must be stipulated for which of the two men the two flashes of light are simultaneous. In the initial set up to the thought experiment it could be simultaneous for either man. But in the real world it will be simultaneous for one man (and therefore not for the other). So in the make believe world of thought experiments, after the initial set it, it then must be stipulated who sees the two flashes of light simultaneously.” And, yes, then the “playing God” would go away. --------------- To swansont: Eddington’s starlight deflection test occurred three years after (1919) after Einstein published his book (1916). I believe that it is appropriate to talk about thought experiment and logic and not just empirical evidence. And I believe that, like all theoretical structures, it is not just one big mass of undifferentiated ideas, but that theoretical structures have a starting point (or a few starting points) which are then built upon. And in my reading of the Theory of Relativity, it seems clear to me that the starting point is the relativity and simultaneity, and then it gets built up from there. The Special Theory of Relativity can exists without the General Theory of Relativity, but the General Theory of Relativity cannot exist without the Special Theory of Relativity. This theory, like all theories, is not just one big undifferentiated mass of ideas. There is structure to it. And examining that theoretical structure (and not just the results of empirical tests), and determining whether or not the structure holds, I believe, is a task worth doing and time not wasted. ---- Thank you all! Cheers! - Christopher
studiot Posted September 18, 2014 Posted September 18, 2014 (edited) The two lightning bolt strikes occur in the inertial frame of reference of the embankment. The two clouds (not explicitly mentioned but that can assumed to be there) are in the inertial frame of reference of the embankment. The two bursts of lighting that make their way from the two clouds to the two points along the embankment are in the inertial frame of reference of the embankment. The two point of impact along the embankment are in the inertial frame of reference of the embankment. And when the two flashes of light from the strikes then leave the points of impact and head towards the two men, they are moving away from two points that are in the inertial frame of reference of the embankment. However, I believe that this is all irrelevant. Finally an answer of sorts but I'm sorry to invoke the old adage There's none so blind as those that won't see. I have enhanced the relevant sentence. I do not like holding discussion with those who declare "whatever you are going to say is irrelevant", without knowing what I actually want to say. Edited September 18, 2014 by studiot 1
swansont Posted September 18, 2014 Posted September 18, 2014 I believe that the Lorentz transformations are based on the relativity of simultaneity, because: 1. That is how Einstein does in fact construct his theory in his book “Relativity: The Special and General Theory.” (He works through the “Two Lightning Bolt Strikes” thought experiment, comes to its conclusion, and then moves onto the Lorentz transformations.) 2. This is how Einstein says he has constructed his theory in his paper “The Foundation of the General Theory of Relativity.” 3. And, the counterintuitive assumption of the Lorentz transformations (“every inertial frame of reference has its own particular time”) is justified by being the conclusion of the “Two Lightning Bolt Strikes” thought experiment. What are the publication dates of these works? Certainly not 1905, when Einstein derived them from the postulate of invariant c, and of course the transforms existed even before that. By what tortured logic could they be based on a later work? To believe that the Lorentz transformations are not based on the relativity of simultaneity, is to believe: 1. In his book he just randomly decides to talk about the relativity of simultaneity just before the Lorentz transformations. By what new tortured logic does the order of presentation have to be random? People arrange material for presentations (and this includes books) according to their own motivations and goals. 2. In his paper his either misspeaks or there is some other interpretation of the meaning of “… there follow, in the well-known way, the relativity of simultaneity, the Lorentzian transformations …” than the plain meaning of the text. 3. And he lays out the Lorentz transformation with an unjustified counterintuitive assumption which could be justified it he had constructed his theory with the Lorentz transformations based on the relativity of simultaneity. What assumption? That “every inertial frame of reference has its own particular time”? That's a conclusion of the Lorentz transform, which is derived from the invariant c postulate. Two The statement “events which are simultaneous in one inertial frame of reference are not simultaneous in another” is counterintuitive. It may seem intuitive to you 100 years post the Theory of Relativity. But, in the early 1900’s it was definitely counterintuitive and could not simply be asserted but rather had to be argued for and demonstrated. It had to be justified. I believe that if the statement “events which are simultaneous in one inertial frame of reference are not simultaneous in another” is not a premise of the “Two Lightning Bolt Strikes” thought experiment, then the “Two Lightning Bolt Strikes” thought experiment does not work. Einstein says the two men are both equal distances from the two flashes of light at the time of their occurrences. And Einstein stipulates that the two flashes of light occur at the same time. And then you will say to me “You say that they occur ‘at the same time’ but you don’t say in what inertial frame of reference.” And then I will say “At this point in this thought experiment the concept ‘events which are simultaneous in one inertial frame of reference are not simultaneous in another’ has not been established yet, That's a curious assertion, given that you've already complained about “every inertial frame of reference has its own particular time” which already implies simultaneity is relative (and who are you to say this wouldn't be intuitive for anyone but yourself?) and so even though the events do occur, as stipulated by Einstein, in the inertial frame of reference of the embankment, this is not relevant. The way a man (or woman) in the early 1900’s would have understood the idea ‘at the same time’ would simply be the common sense idea that they occurred ‘at the same time’ without any need to reference inertial frames of reference. It is once Einstein establishes ‘events which are simultaneous in one inertial frame of reference’ that he then logically deduces ‘every inertial frame of reference has its own particular time.’ At this point in this thought experiment neither of these two ideas have been established yet. It is the purpose of this thought experiment to establish this, and so, by definition, this has not yet been established at the start of the thought experiment.” And then you will say to me “You don’t understand what you are talking about.” And then I will say “Okay let us agree to disagree.” Disagree all you want. You're wrong.
pzkpfw Posted September 18, 2014 Posted September 18, 2014 ... Cool. Where? ... We've been over that. This is where I give up. You are determined to keep your odd interpretation, and this is all just going to go around in circles.
xyzt Posted September 18, 2014 Posted September 18, 2014 There should be a way to lock this thread, it has been going in circles for a long time. There is no way of convincing christopher that he's wrong, so what is the point of wasting server storage and network bandwidth?
Phi for All Posted September 18, 2014 Posted September 18, 2014 This theory, like all theories, is not just one big undifferentiated mass of ideas. There is structure to it. And examining that theoretical structure (and not just the results of empirical tests), and determining whether or not the structure holds, I believe, is a task worth doing and time not wasted. ! Moderator Note Not when you reject empirical test results for your own personal incredulity over how the theory is structured. Not when you reject the efforts of several knowledgeable people trying to show you where your errors lie. And certainly not when you ask for help but continue to proffer your own flawed misunderstanding of a thought experiment as a better explanation. You've had direct feedback from multiple sources that that part, at least, was a great waste of time. The thread will be closed if its current direction remains unchanged. Use what time you have left wisely, and don't waste it responding to this modnote. 1
Le Repteux Posted September 19, 2014 Posted September 19, 2014 There should be a way to lock this thread, it has been going in circles for a long time. There is no way of convincing Christopher that he's wrong, so what is the point of wasting server storage and network bandwidth? You elude the fact that Christopher does not seem to find a way to convince others either. Scientific method demands that we are as objective as possible, which means that we have to do the effort of considering both point of views in a discussion. I have observed this effort in Christopher's posts, but not in yours. When all the possible arguments have been presented and people still disagree with the conclusion, the best way to close the subject is to "agree that we disagree", as Christopher pointed out, not to blame the other camp of being wrong, as you do here.
xyzt Posted September 19, 2014 Posted September 19, 2014 (edited) You elude the fact that Christopher does not seem to find a way to convince others either. Scientific method demands that we are as objective as possible, which means that we have to do the effort of considering both point of views in a discussion. I have observed this effort in Christopher's posts, but not in yours. Actually, your claims are false. I have debunked christopher's errors earlier in the thread, with hard facts (i.e. math and physics). You need to go back at the beginning of the thread and find the debunking posts. I also debunked your attempts at hijacking this thread with your own fringe ideas. Also with hard facts , i.e. math and physics. When all the possible arguments have been presented and people still disagree with the conclusion, the best way to close the subject is to "agree that we disagree", as Christopher pointed out, not to blame the other camp of being wrong, as you do here. This is not the way science works, mainstream science does not compromise with crank claims, no matter how persistent and vociferous the proponents are. Edited September 19, 2014 by xyzt
swansont Posted September 19, 2014 Posted September 19, 2014 You elude the fact that Christopher does not seem to find a way to convince others either. Scientific method demands that we are as objective as possible, which means that we have to do the effort of considering both point of views in a discussion. I have observed this effort in Christopher's posts, but not in yours. When all the possible arguments have been presented and people still disagree with the conclusion, the best way to close the subject is to "agree that we disagree", as Christopher pointed out, not to blame the other camp of being wrong, as you do here. Points that are demonstrably wrong do not merit equal consideration. The proper result is not some compromise, halfway between the correct answer and any arbitrary incorrect one. ckr's premises are flawed and his claims are both invalid and wrong.
studiot Posted September 19, 2014 Posted September 19, 2014 (edited) You elude the fact that Christopher does not seem to find a way to convince others either. Scientific method demands that we are as objective as possible, which means that we have to do the effort of considering both point of views in a discussion. I have observed this effort in Christopher's posts, but not in yours. When all the possible arguments have been presented and people still disagree with the conclusion, the best way to close the subject is to "agree that we disagree", as Christopher pointed out, not to blame the other camp of being wrong, as you do here. I consider it a great shame that as the only responder offering a way forward, both you and Christopher chose to reject what I had to say before I said it. I think the problem lies in a misunderstanding of terminology. So I asked a simple question to work through the problem from the beginning. The point is that the lightning (along with everything else in the universe) is not in any frame at all. This is a common turn of phrase that is actually wrong in strict terms. The lightning is in the universe, and every frame will identify the same point, but call it by different names. That is the whole point of Relativity. Consideration of this would lead to a resolution of your difficulties. Edited September 19, 2014 by studiot
Le Repteux Posted September 19, 2014 Posted September 19, 2014 Points that are demonstrably wrong do not merit equal consideration. The proper result is not some compromise, halfway between the correct answer and any arbitrary incorrect one. ckr's premises are flawed and his claims are both invalid and wrong. He only claims that the mind experiment in question does not explain the real observations that we make, not that the data from these observations are false. I agree with him, whatever the way you turn that mind problem around, there is no way out, so why not admit that there might be something that we do not understand about motion yet?
Dekan Posted September 19, 2014 Posted September 19, 2014 (edited) The point is that the lightning (along with everything else in the universe) is not in any frame at all. When you say "everything else", would you make an exception for "sound". That definitely does seem to be frame-related, ie to atmospheric density. At sea-level, where the atmosphere is densest, the speed of sound (Mach 1) is about 760 mph. But at a higher altitude, say 30,000 ft, Mach 1 decreases to about 660 mph. So consider a aircraft which can fly at a maximum speed (relative to the ground), of 700 mph. If it flies at that speed nearly at ground-level, (obviously a few hundred feet above), it will be "subsonic" - ie below Mach 1. Whereas if the plane flies at 30,000 ft, it will exceed Mach 1, and so be "supersonic". The words "subsonic" and "supersonic" are thus "frame-related". And so "sound" has a definite frame - atmospheric density. Edited September 19, 2014 by Dekan 1
Le Repteux Posted September 19, 2014 Posted September 19, 2014 The lightning is in the universe, and every frame will identify the same point, but call it by different names. That is the whole point of Relativity. Consideration of this would lead to a resolution of your difficulties. I understand what you mean Studiot, but I am sure that if we discussed your point in details, it would not work either. If the world goes round, it is not because of simultaneity, it is because of interactions. Bodies do not mind about what is happening elsewhere, they mind about what is happening right now, and right now for them as far as light is concerned is when it is perceived, whatever the motion of that body. 1
studiot Posted September 19, 2014 Posted September 19, 2014 If the world goes round, it is not because of simultaneity, it is because of interactions. Bodies do not mind about what is happening elsewhere, they mind about what is happening right now, and right now for them as far as light is concerned is when it is perceived, whatever the motion of that body. There you go again. Introducing things I did specifically didn't to try to prove me wrong. I agree none of these things quoted have anything to do with what I said.
Le Repteux Posted September 19, 2014 Posted September 19, 2014 (edited) Actually, your claims are false. I have debunked christopher's errors earlier in the thread, with hard facts (i.e. math and physics). You need to go back at the beginning of the thread and find the debunking posts. I also debunked your attempts at hijacking this thread with your own fringe ideas. Also with hard facts , i.e. math and physics. Only data are facts, the rest is imagination. This is not the way science works, mainstream science does not compromise with crank claims, no matter how persistent and vociferous the proponents are. Pot, kettle, black: remember? Edited September 19, 2014 by Le Repteux
xyzt Posted September 19, 2014 Posted September 19, 2014 Only data are facts, the rest is imagination. Pot, kettle, black: remember? You mean that you have been hijacking this thread with your crank claims? Absolutely.
studiot Posted September 19, 2014 Posted September 19, 2014 (edited) At sea-level, where the atmosphere is densest, the speed of sound (Mach 1) is about 760 mph. But at a higher altitude, say 30,000 ft, Mach 1 decreases to about 660 mph Hello Dekan, can you tell me what are the units (dimensions if you like) of "Mach 1" please? I'm sorry I missed your comment before, because of the page change. Edited September 19, 2014 by studiot
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