OceanBreeze Posted January 25, 2019 Report Posted January 25, 2019 How about the theoretical test (thought experiment) that SR theory has proposed for itself, i.e., the twin paradox "resolution?" 1. Why doesn't the reciprocal dilation show up there, do you think? 2. If it had been demonstrated there, which twin would be younger? Would each twin be younger than the other when they were reunited? 1) Because it is a "thought experiment" and can end up however the "thought thinker" wants it to end up! But basically it is an asymmetrical situation so there is no reason to expect it to produce symmetrical outcome. The idea that it is some sort of paradox is silly. 2) That depends on how the thought experiment is set up. If one twin gets in her ship and leaves from a black hole and returns, she may well find that the stay-at-home twin has aged less, due to gravitational time dilation being greater than her velocity time dilation. That is what we see in the GPS system. The twin paradox is something to amuse the kids with, not for serious discussion. As a side note, I am finding out that we actually agree more than I originally thought we did, about this subject.I don't recall if I was one of the people who attacked you on this forum (I don't think I was) but if I did, I apologize. Quote
Moronium Posted January 25, 2019 Report Posted January 25, 2019 (edited) But basically it is an asymmetrical situation so there is no reason to expect it to produce symmetrical outcome. The idea that it is some sort of paradox is silly. Yes, of course they are not symmetrical. One is moving (absolutely), and one isn't. But perhaps you overlook the nature of the "paradox." It's certainly not that one ends up younger than the other. The paradox is "created" by the further proposition, asserted by SR, that both are correct when assuming the other is the one moving. They can't both be correct, so why is that claim ever made in the first place? Ultimately the "paradox" is this: It would be impossible to get an absolute answer from any theory which is truly relative. Edited January 25, 2019 by Moronium Quote
Moronium Posted January 25, 2019 Report Posted January 25, 2019 I don't recall if I was one of the people who attacked you on this forum (I don't think I was) but if I did, I apologize. I don't think you were either, although you may have been on the verge of it, at times. Quote
OceanBreeze Posted January 25, 2019 Report Posted January 25, 2019 (edited) Yes, of course they are not symmetrical. One is moving (absolutely), and one isn't. But perhaps you overlook the nature of the "paradox." It's certainly not that one ends up younger than the other. The paradox is "created" by the further proposition, asserted by SR, that both are correct when assuming the other is the one moving. They can't both be correct, so why is that claim ever made in the first place? Ultimately this "paradox" is this: It would be impossible to get an absolute answer from any theory which is truly relative. They both are in relative motion. I don't believe in absolute motion, but there is an obvious difference between the two motions, as I tried to explain with the rock-throwing example. Only one of them is moving with a velocity and kinetic energy that can be directly correlated with the energy that was used to cause their motions in the first place. That is the spaceship, not the earth. I think that is the key. Do you understand what I mean by that? If not, I can post a numerical answer later.Another way of looking at it is not to consider their motions as relative to each other, but instead relative to their original center of mass. The COM will remain exactly where it was, before they moved and even after they have moved. Edited January 25, 2019 by OceanBreeze Quote
OceanBreeze Posted January 25, 2019 Report Posted January 25, 2019 I don't think you were either, although you may have been on the verge of it, at times. That's good to know! Quote
Moronium Posted January 25, 2019 Report Posted January 25, 2019 (edited) They both are in relative motion. I don't believe in absolute motion, but there is an obvious difference between the two motions, as I tried to explain with the rock-throwing example. Only one of them is moving with a velocity and kinetic energy that can be directly correlated with the energy that was used to cause their motions in the first place. That is the spaceship, not the earth. I think that is the key. Do you understand what I mean by that? If not, I can post a numerical answer later.Another way of looking at it is not to consider their motions as relative to each other, but instead relative to their original center of mass. The COM will remain exactly where it was, before they moved and even after they have moved. Well, to be honest, I'm not sure what you're trying to say here. We must have a different definition of "absolute motion," because, as far as I'm concerned, your rock example is an instance of absolute motion. I do agree that the role of energy, as well as the concept of "work" is key, though. Edited January 25, 2019 by Moronium Quote
OceanBreeze Posted January 25, 2019 Report Posted January 25, 2019 OK I will get back to you in an hour or so, I have a few things to do. Hopefully I can explain it better then. Quote
Moronium Posted January 25, 2019 Report Posted January 25, 2019 (edited) OK I will get back to you in an hour or so, I have a few things to do. Hopefully I can explain it better then. OK, cool. In the meantime I'll try to elaborate a little on what my uncertainty is about. To begin with, I think some people misconstrue the meaning of "relative" in the term "relative motion." Often they simply mean that all motion is relative to "something," and that it is meaningless (or incomplete) to claim that something is moving without also specifying what it is moving relative to. They are right about that, but I think they are misconstruing the intended meaning when they say "Therefore all motion is relative" (because it is always relative to something). Even absolute motion is always relative to something. The usual way to look at the term "absolute motion" is to say that it's not "frame dependent." In SR, acceleration is deemed to be absolute, for example, because all frames will agree when an object is accelerating. It's not just a "matter of perspective." Another way to look at it is like this: Some say that an heliocentric view of the solar system is "equivalent to" a geocentric one. That they are "equally valid." The ultimate proposition (in SR) is that ALL frames are equally valid. There can be no reason to "prefer" one over another, etc. Therefore "all (inertial) motion is strictly relative--a matter of perspective only." I say that's hogwash. You say that you "don't believe in absolute motion," but I think you actually do (by my definition of the term). For that matter, I think that virtually every devout relativist believes in absolute motion, and they often inadvertently express that belief, all while denying that absolute motion can exist. Edited January 25, 2019 by Moronium Quote
Moronium Posted January 25, 2019 Report Posted January 25, 2019 (edited) For that matter, I think that virtually every devout relativist believes in absolute motion, and they often inadvertently express that belief, all while denying that absolute motion can exist. For example, when Einstein claimed, in his original 1905 paper, that an organism that took a journey at the speed of light would come back younger than the peers it left behind, he was asserting the existence of absolute (not merely relative) motion. He was, in effect, claiming that the animal was "really" moving, and not that it was all merely a matter of perspective. Moving with respect to what? Well, among other things, with respect to the peers he left behind. He was the one moving, not them. Edited January 25, 2019 by Moronium Quote
OceanBreeze Posted January 25, 2019 Report Posted January 25, 2019 OK I am just going to dump this here for now as I am busy with other things, but will be back again later: A baseball pitcher can throw a ball with a mass of 0.15 kg at over 90 mph, so I can safely use a ball with a mass of 0.2 kg and have it thrown at 70 mph (28 m/s) The kinetic energy KE of that ball is 1/2 mv^2 = 78.4 J Let’s say this is a very efficient pitcher so that is the amount of energy he puts into the throw.Now, according to SR enthusiasts and various other complete whackos, “you can’t tell which is moving!”“It could be the ball or it could be the entire earth depending on which reference frame you choose!” The concept of reference frames is a very useful one, but when it is carried to extremes, you get the above kinds of absurdities. I am about the prove that you can know which one is moving at 28 m/s and I will not resort to absolute motion, just Newton’s Laws. IF the earth was moving at 28 m/s, with respect to the ball, it would have a kinetic energy of1/2 MV^2 where M is the mass of the earth, 5.98E24 kg That works out to 2.34E27 J, but we only started with 78.4 J I call that a clear case of violating conservation of energy! So, this idea of relative motion and “you can’t tell” what is really moving can be nicely resolved just by energy considerations. Actually, all you need is common sense, but that is something that SR enthusiasts seem to completely lack. If I had a sailor come on deck and ask me if it really is the ship moving through the water and not the other way around, I would be tempted to thrown him overboard! To determine the actual velocity of the planet earth, resulting from the throw, according to Newton’s Laws, we can use the fact that momentum is also conserved. Before the throw, the total momentum of ball and earth was zero and it must be zero after the throw. That is, (0.2 kg) (28 m/s) + (5.98E24 kg) (V_earth) = 0 And V_earth works out to the incredibly small velocity of 9.36E-25 m/s The KE of the earth then is 2.62E-24 J an incredibly tiny amount, but not zero. So, there is relative motion but the 28 m/s only applies to the baseball and it is the baseball that will have some tiny amount of time dilation. The baseball that is thrown will be found to be ever so slightly “younger” than the one the umpire is keeping in his vest, by applying the Lorentz transform. The exact same reasoning can be applied to the space-faring twin without all the cartoonish space time diagrams and “deep” philosophical ruminations. None of what I have written here overturns SR and I rely a great deal on the GPS and have no doubt at all that time dilation is real. I do have a reasonable doubt that velocity time dilation is reciprocal and I would very much like to see some experimental evidence to either support it or debunk it. Quote
Moronium Posted January 25, 2019 Report Posted January 25, 2019 (edited) None of what I have written here overturns SR and I rely a great deal on the GPS and have no doubt at all that time dilation is real. I do have a reasonable doubt that velocity time dilation is reciprocal and I would very much like to see some experimental evidence to either support it or debunk it. I agree with virtually everything you said in that post, except this part. For one thing, the GPS does not use SR. It does (quite justifiably) rely heavily on the presumed validity of the lorentz transforms. But the mere fact that the LT are being employed does NOT mean that SR is being employed. The LT are not unique to SR (and, as a matter of fact, Einstein lifted them, whole cloth, from a theory of relative motion that contradicts SR). The theory utilized by the GPS presumes absolute simultaneity, not the relative simultaneity of SR. It also relies on a preferred frame--a practice which is strictly prohibited by SR. It treats motion as being absolute, not relative. In short it employs a theory which is antithetical to SR, a point which I have made before. Yet many still assume that the GPS relies on, and confirms, SR. Attempting to use SR within the GPS would result in utter chaos and complete failure of the whole system. The same is true of the H-K experiment, which was originally conducted almost a half a century ago. Yet you still hear many claiming that H-K "confirms" SR. It doesn't. It repudiates it. Let's say that two competing theories each hold that "motion exists." If it is proved that "motion exists" does that "prove" one theory or the other? Of course not, they both agree on that point. H-K originally advertised their experiment as "confirming" SR, because it showed that time dilation does indeed occur. But, again, other theories also predict time dilation, so why single out SR as having been confirmed? As a theoretical matter, SR claims that the only type of inertial time dilation that can exist is "reciprocal." But that is not what H-K found. The time dilation which resulted was strictly asymmetrical. And the H-K data could only be adequately explained by employing a preferred frame and ignoring the SR dictum that no such frame can ever legitimately be used.. Again, if you want to claim that neither H-K nor the GPS have anything to say about SR because SR cannot be applied in those conditions, OK. But don't also conclude that SR has been confirmed by them either, then. Edited January 25, 2019 by Moronium Quote
Moronium Posted January 25, 2019 Report Posted January 25, 2019 (edited) I will take a minute for a closer look at SR in the context of the twin paradox (and your baseball example). SR does NOT claim that the motion of an accelerating object is "relative." It therefore does not claim that time dilation is reciprocal in those instances or that the accelerating object is not "really" (absolutely) moving. So what does it do? It claims that when the travelling twin is accelerating to, and beyond, the escape velocity of the earth's gravity that it is really moving, BUT that as soon as it ceases to accelerate and simply coasts inertially THEN the passenger can, and indeed MUST, consider himself to be absolutely motionless. Of course that would mean that the earth is moving with respect to him and not vice versa, and that therefore, it would have the "moving clock," and therefore its clock is running slower than his. The implication is that the second he stops accelerating, he comes to an abrupt and complete stop. This would, of course, violate Newton's law of inertia, which is just one reason why the notion that the space traveler is no longer moving is ridiculous. Yet that is the case according to the theoretical requirements of SR. And SR adherents will insist until the cows come home that this is the only proper view for him to take. SR is simply not a theory that can be said to comport with objective reality, however "mathematically consistent" it may be. Edited January 25, 2019 by Moronium Quote
Moronium Posted January 25, 2019 Report Posted January 25, 2019 (edited) There are of course reasons why SR insists that its adherents accept such absurdities. For SR to work out, there MUST be a conflict amongst observers about who is moving. If the space traveler ever conceded that he was actually moving, then SR would fall apart. In that event, the speed of light would no longer be constant and isotropic in his frame. He would have to concede that his rods were contracted, and that his clock was slowed, and that therefore light was not actually traveling a c even though he measured it to be (with his uncorrected instruments). Edited January 25, 2019 by Moronium Quote
marcospolo Posted February 6, 2019 Author Report Posted February 6, 2019 There MUST be an absolute reference frame for Special Relativity to work. The Relativist's claim that light ALWAYS goes at a fixed speed, means that LIGHT itself provides the absolute reference from which all things are relative. If you want to think all Einstein like... then imagine that light is totally motionless, absolutely stationary, and its everything else that is in motion, at a base speed of "c" plus or minus the relative speeds of the individual objects that are also relative to each other. Whichever way you look at it, physics of any ones flavor must have some agreed absolute origin from which to do comparative physics. With General Relativity, there is also the necessary absolute frame of reference, the preferred frame.Although both GR and SR are failed Hypothesizes, (proven to be impossible from many angles but many people, over the last 100 years) there IS in fact an absolute frame in GR.It is the very SPACETIME fabric that is supposed to be all pervading and its current state, of a localized area of spacetime, can be mathematically expressed as being warped by the nearby presence of some massive body. Warped or rippled relative to WHAT? Well, relative to its own un-rippled natural state. A homogeneous, isotropic fabric. Sounds exactly like a great static frame of reference to me. If one is to believe in such nonsense as Spacetime, that is. Relativists need to both embrace an idea and at the same time denounce it to keep their ideas alive. They want to have their cake as well as eat it. They can't pick one side and stick to it, because contradiction is inherent in the whole theory. Quote
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