A puzzle for the SRians
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From: PD on 27 Jul 2010 13:49 On Jul 27, 11:53 am, Hayek <haye...(a)nospam.xs4all.nl> wrote: > PD wrote: > > On Jul 27, 10:54 am, Hayek <haye...(a)nospam.xs4all.nl> > > wrote: > >> PD wrote: > >>> On Jul 27, 9:25 am, Hayek > >>> <haye...(a)nospam.xs4all.nl> wrote: > >>>> Daryl McCullough wrote: > >>>>> Hayek says... > >>>>>> I find a lot of flaws in these "gedanken". > >>>>>> For instance, Einstein assumes that the > >>>>>> event only takes place if you see the > >>>>>> lightflash of the event in your frame of > >>>>>> reference. > >>>>> He makes no such assumption. > >>>>>> Light to me, is only an imperfect carrier > >>>>>> of information, just as sound is. With > >>>>>> instantaneous communication, and a correct > >>>>>> definition of time, and there is no such > >>>>>> thing anymore as relativity of > >>>>>> simultaneity. > >>>>> That's exactly right. Relativity of > >>>>> simultaneity is a consequence of there being > >>>>> an upper bound to communication speed. If > >>>>> there is no upper bound, then relativity is > >>>>> wrong. > >>>> Brilliant remark. But suppose that someone > >>>> finds a way to send instantaneous messages, by > >>>> means of Quantum effects. This is not even far > >>>> fetched, as the Aspect experiment, now even > >>>> some 10 miles apart, indicate that entangled > >>>> photons seem to send information about their > >>>> polarization across that distance. But let's > >>>> not start that discussion again. > >>> I do think it's worth starting that discussion > >>> again. There is a DISTINCT difference between ftl > >>> communication and quantum entanglement. FTL > >>> communication in a two-particle system DEMANDS > >>> the principle of locality, which says that two > >>> particles in a state are separable in their > >>> properties and that any change in one particle > >>> cannot influence the state of the other particle > >>> except for a signal transmission from one to the > >>> other. An Aspect-like result would then imply FTL > >>> communication. > >> Exactly. And the result *were* Aspect like, and not > >> Bell-like. > > > I'm sorry, you may be under some misapprehension > > about what Bell's theorem says. Bell's theorem was of > > the sort: "If quantum mechanics is right, then you > > will see this measurement with quantity X. If local > > hidden variables are in play, then you will this same > > measurement with quantity Y." > > And Aspect found that it was X, quantum mechanics was > right. As it so happens, I read the story about Bell, > and he gambled on hidden variables. > > >> [..] > > >>> The hyperbolic structure of spacetime, which by > >>> the way has enormous implications which all agree > >>> with experiment, rules out FTL. > >> But the whole of spacetime does not mention > >> uncertainty, nor any other qm effect. > > > And that's just flat wrong. Starting with Dirac, but > > certainly including just about any relativistic > > quantum field theory you can name (QED, QCD, > > electroweak, etc.), there is a full reconciliation of > > spacetime geometry with quantum mechanics. > > You seem unable to make the difference between QFT > includes GR or GR includes QFT. The difference between SR and GR is flat hyperbolic geometry vs curved hyperbolic geometry. The hyperbolic nature remains, and it is that which prohibits FTL communication. > > I meant that GR does not include QM or QFT at all, yet > FTL was "ruled out" before that. The later theory > adapted the former, in the limit case. And QFT, as all > Quantum descriptions describe the observables only. I > think Bohr was right in saying that all measurements are > classical. At uncertainty nothing can be measured. If > measurements are classical then they must obey GR. > > > > > > > > > Just because it did not appear in the FIRST FEW > > papers about spacetime does not mean that work has > > not been done since then. > > >> [..] > > >>>> Suppose we have instant messaging, what about > >>>> relativity would be wrong ? Time would still > >>>> dilate, rods shrink, and even RoS would still > >>>> apply if you only used light as communication. > >>> No. Rods do not shrink because of light > >>> communication. > >> I did not say that. Why do you always exploit > >> semantics to disprove something that is not there? > >> A conversation requires intelligence on both sides. > >> Try reading the sentence in the following way : > >> (Time would still dilate, rods shrink ) AND (even > >> RoS would still apply if you only used light as > >> communication) > > >> I did not say that time dilates and rod shrink > >> because of light communication, I meant that part > >> only for RoS. > > > And the same is true for RoS. It is not reliant on > > light communication. The first time its plausibility > > was explained, that explanation involved light, but > > that is incidental. > > Sam Wormley has a different opinion on that, which I > agree with. > > Uwe Hayek. > > -- > We are fast approaching the stage of the ultimate > inversion : the stage where the government is free to do > anything it pleases, while the citizens may act only by > permission; which is the stage of the darkest periods of > human history. -- Ayn Rand > > I predict future happiness for Americans if they can > prevent the government from wasting the labors of the > people under the pretense of taking care of them. -- > Thomas Jefferson. > > Socialism is a philosophy of failure, the creed of > ignorance, and the gospel of envy, its inherent virtue > is the equal sharing of misery. -- Winston Churchill.- Hide quoted text - > > - Show quoted text -- Hide quoted text - > > - Show quoted text -
From: Daryl McCullough on 27 Jul 2010 13:58 Hayek says... >In the latest Now, every object has a velocity, setting >direction and speed. What does "velocity" mean, if not the derivative of position with respect to time? >Caused by inertia. >I suppose you could say that "time is a function of >change of position". That doesn't make sense. You can't say that position has *changed* unless you have two different times to compare those positions. -- Daryl McCullough Ithaca, NY
From: Hayek on 27 Jul 2010 14:35 Daryl McCullough wrote: > Hayek says... > >> In the latest Now, every object has a velocity, >> setting direction and speed. > > What does "velocity" mean, if not the derivative of > position with respect to time? It is like deprogramming a hare khrishna or something. :-) Imagine a three dimensional space. Just three dimensions. Now imagine an object in it. Now let this object move , and normalize its speed 1. When a second object covers twice the ground as the first then say it has speed 2. The position of the objects is called the Now. There is no past, no future, just the two objects and their changing positions. No need to define time or have a time dimension. >> Caused by inertia. I suppose you could say that >> "time is a function of change of position". > > That doesn't make sense. You can't say that position > has *changed* unless you have two different times to > compare those positions. These are only in your memory. That is playing tricks on you. Move a ball from a to b. It is no longer in a, except in your memory. I makes more sense than a time dimension. You cannot go back by traveling through time to the moment that object was still in a. The object has moved and is no longer in a. period. 3D+motion is not equal to 4D. Uwe Hayek. -- We are fast approaching the stage of the ultimate inversion : the stage where the government is free to do anything it pleases, while the citizens may act only by permission; which is the stage of the darkest periods of human history. -- Ayn Rand I predict future happiness for Americans if they can prevent the government from wasting the labors of the people under the pretense of taking care of them. -- Thomas Jefferson. Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery. -- Winston Churchill.
From: kenseto on 27 Jul 2010 14:45 On Jul 27, 10:09 am, PD <thedraperfam...(a)gmail.com> wrote: > On Jul 27, 8:50 am, kenseto <kens...(a)erinet.com> wrote: > > > > > > > On Jul 26, 5:57 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Jul 26, 4:12 pm, kenseto <kens...(a)erinet.com> wrote: > > > > > Einstein's train gedanken is modified as follows: > > > > When M and M' are coincide with each other......two lightning strikes > > > > hits the ends of the train and the light fronts arrive at M' non- > > > > simultaneously. > > > > Question for the SRians: does this mean that according to the SR > > > > concept of relativity of simultaneity M will see the light fronts > > > > arrive at him simultaneously? > > > > Not necessarily. It depends on the speed of the train. > > > > But for a given pair of lightning strikes, there will be at least ONE > > > reference frame with an observer M" for whom the light fronts arrive > > > simultaneously. > > > But there are infinite nmuber pairs of light fronts that arrive at M > > and M' non-simultaneously. > > Not for a given pair of lightning strikes there aren't. I didn't specifiy any given pair of strikes. > > > That means that M and M' agree with each > > other on all non-simutlaneity events. > > What? No. You mean that for some pairs of strikes M and M' will both > say the strikes are nonsimultaneous? Yes, that's true, but the two > observers will say there is a different amount of time between them. But nevertheless they both agree that if M' sees two strikes to be non- simultaneous then M will also see the same two strikes to be no simultaneous. I agree that M' and M will say there is a different amount of time between them. > So the "agreement" is pretty shallow. No not shallow at all. It illustrates that M and M' agree on non- simultaneity of same two events...this follows that M and M' will also agree on simultaneity of the same two event and thus refute the SR claim of relativity of simultaneity. Also they will agree that simultaneity occur at different time in the train than on the track. > > > That seem to violate the basic > > tenet of relativity of simultaneity. > > I don't know what you think the basic tenet of relativity of > simultaneity is. > Did you think that the basic tenet of relativity of simultaneity is > that if one observer says two events are non-simultaneous, then > another observer will say they are simultaneous? Yes RoS says that if M' sees two events to be non-simultaneous then M should sees the same two events to be simultaneous....that's what RoS claim. >If that's what you > thought it said, you're wrong. It doesn't say that at all. Yes it does. Ken Seto > > > > > Your assertion that there is one pair of light fronts that will arrive > > at M" simutltaneously is irrelevant....why? because M" is not at the > > middle of the train. > > Yes, it is. > > > > > > > It is true that there is one pair of light fronts out of the infinite > > pairs of light fronts that will arrive at M' simultaneously but that > > pair of light fronts will also arrive at M simultaneously....why? > > Because the speed of light is independent of the motion of the ends of > > the train. > > A fourth grader can understand that and yet you call yourself a > > physics professor. <shrug> > > > Ken Seto. > > > > It will also be possible to find a pair of lightning strikes such that > > > they arrive at M' non-simultaneously and at M simultaneously. Just > > > maybe not the pair you're talking about. > > > > > Since there are an infinite number of pairs of strikes that can cause > > > > the light fronts to arrive at M' non-simultaneously, does that means > > > > that there are infinite pairs of strikes that M will see their light > > > > fronts to arrive at him simultaneously????? > > > > No. Just one pair. > > > > Idiot. > > > > Ineducable idiot. > > > > Shamelessly self-immolating, ineducable idiot. > > > > > Ken Seto > > > > In case you thought you had some brilliant insight here, Ken, no. You > > > are asking a 6th grade question.- Hide quoted text - > > > - Show quoted text -- Hide quoted text - > > - Show quoted text -- Hide quoted text - > > - Show quoted text -
From: Daryl McCullough on 27 Jul 2010 14:57
Hayek says... >Imagine a three dimensional space. Just three dimensions. > >Now imagine an object in it. > >Now let this object move , and normalize its speed 1. What does "move" mean, if you don't have a notion of time? I know what *I* mean by saying "the object has moved". It means that the object at one time is at a different location than it was at an earlier time. >>> Caused by inertia. I suppose you could say that >>> "time is a function of change of position". >> >> That doesn't make sense. You can't say that position >> has *changed* unless you have two different times to >> compare those positions. > >These are only in your memory. That is playing tricks on >you. Move a ball from a to b. What does "move" mean? You are engaging in circular reasoning. To talk about "moving" a ball from a to b means that at one time, the object is at a, and at a later time, the object is at b. But that presupposes that we already understand what "time" means. -- Daryl McCullough Ithaca, NY |