Known physics defeated by simple puzzle?
in [Relativity]
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From: Inertial on 8 Apr 2010 00:32 "Sue..." <suzysewnshow(a)yahoo.com.au> wrote in message news:3579bfca-d6e1-41d9-b0d7-20c119920d1d(a)g11g2000yqe.googlegroups.com... > On Apr 7, 11:09 pm, "Inertial" <relativ...(a)rest.com> wrote: >> "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message >> >> news:541c6f6d-a61d-4ea7-bf46-0c8e404289ec(a)11g2000yqr.googlegroups.com... >> >> >> >> > On Apr 7, 5:24 pm, Ste <ste_ro...(a)hotmail.com> wrote: >> >> On 7 Apr, 15:49, "Inertial" <relativ...(a)rest.com> wrote: >> >> >> > "Ste" <ste_ro...(a)hotmail.com> wrote in message >> >> >> >news:cf5cd01b-0da3-41b0-88b5-69b2e678a011(a)z7g2000yqb.googlegroups.com... >> >> >> > > On 7 Apr, 05:08, "Inertial" <relativ...(a)rest.com> wrote: >> >> > >> "Ste" <ste_ro...(a)hotmail.com> wrote in message >> >> >> > >> >> > Again, hidden in the meaning here is 100km/h >> >> > >> >> > *relative to what*. An object cannot travel at *both* >> >> > >> >> > 100km/h >> >> > >> >> > *and* >> >> > >> >> > 50 >> >> > >> >> > km/hr *relative to me*. >> >> >> > >> >> I didn't say it could. But we are talking about things being >> >> > >> >> real.. >> >> > >> >> you >> >> > >> >> claim that all observers have to agree about the value for it >> >> > >> >> to >> >> > >> >> be >> >> > >> >> real. >> >> >> > >> > Yes, I do say that! >> >> >> > >> So velocity is not real, momentum is not real, kinetic energy is >> >> > >> not >> >> > >> real, >> >> > >> length is not real, time is not real etc etc. >> >> >> > >> Is that REALLY what you want to be saying? >> >> >> > > But I'm not saying that, am I? >> >> >> > By implication, yes, you are >> >> >> > > You're the one putting these words in >> >> > > my mouth. >> >> >> > No .. I am applying your definition. >> >> >> > If that is NOT what you want to be saying, then you should change >> >> > yoru >> >> > definition >> >> >> No Inertial, you're not applying my definition, because you don't even >> >> understand my definition. >> >> > We can't use your definition because Einstein's >> > definition puts the ballistic light that >> > W. deSitter never found on an imaginary axis. >> >> Umm .. no. There's no ballistic light required for SR. Only the time >> between light being emitted at the source and arriving at its destination >> gives a speed of c for all inertial reference frames. How it gets there >> is >> not really a matter for SR .. it is propagation method agnostic. > > That is what I meant that you don't need SR > except to remove Newton's Coupuscles. You need it to model reality (at least in the scope of applicability of SR, ignoring GR for the time being) > It is in the narrative. > Theorem of the Addition of Velocities > > If he had not suggested source dependent light > speed in the narrative, the trick with > stipulations and definitions and simultaniety > would be unnecessary. I think you will find > the modern Fitzpatrick text gets by just > fine without all that. > >> >> OMG> Sue makes a quote that is actually on topic.... >> >> > <<There is only one demand to be made of the >> > definition of simultaneity, namely, that in >> > every real case it must supply us with an >> > empirical decision as to whether or not the >> > conception that has to be defined is fulfilled. >> > That my definition satisfies this demand is >> > indisputable. That light requires the same time >> > to traverse the path A �> M as for the path B �> M >> > is in reality neither a supposition nor a hypothesis >> > about the physical nature of light, but a stipulation >> > which I can make of my own freewill in order >> > to arrive at a definition of simultaneity.�>> >> >http://www.bartleby.com/173/8.html >> >> Of course, to be useful, such a 'stipulation' for simultaneity needs to >> be >> consistent, reflexive etc. > > It is just for the corpuscle fans. Doesn't matter which fans >> Also note that the equal time required is indeed a direct consequence of >> the >> second postulate. That correctly synchronized clocks show those equal >> times >> as equal is almost self-evident. > > I think it may only be a good approximation. I didn't say anything that could be interpreted as an approximation. So what is it you are talking about? > The below feels a bit like curve-fitting. A > maths major could probably spot it if > if is. ;-) > > <<According to the Galilean transformation, the > *apparent* speed of propagation in S' is c-v, > which violates the relativity principle. Can we > construct a new transformation which makes the > velocity of [ballistic] light invariant between > different inertial frames,>> > http://farside.ph.utexas.edu/teaching/em/lectures/node109.html Nothing to do with curve fitting there > Anyway, It is good enough to constuct a space-time > and unnecessary to resolve the two postulates because > ballistic light is not real. It doesn't matter whether light is ballistic or not to SR.. Only that the speed is c in all inertial frames, and that physics laws work the same in all inertial frames. The rest follows from there. >> > The ballistic light only *appears* for people >> > of his time that applied Newtons mechanics to >> > light particles. >> >> >http://en.wikipedia.org/wiki/Emitter_theory >> >> > In the formal statement the ballistic >> > property vanishes. >> >> >http://www.bartleby.com/173/17.html >> >> There was (and is) no need for ballistic light in SR. You seem confused >> that it ever did. > > Blame Einstein, not me. Einstein did not say anything about light having to be ballistic for SR to work. So nothing to 'blame' Einstein for. > "Theorem of the Addition of Velocities" > http://www.bartleby.com/173/13.html > > Modern version is much easier. > > < where epsilon_0 and mu_0 are physical constants which > can be evaluated by performing two simple experiments > which involve measuring the force of attraction between > two fixed charges and two fixed parallel current carrying > wires. According to the relativity principle, these experiments > must yield the same values for epsilon_0 and mu_0 in all > inertial frames. Thus, the speed of light must be the > same in all inertial frames. >> > http://farside.ph.utexas.edu/teaching/em/lectures/node108.html Yes .. you can use things like maxwell's equations combined with the principle of relativity to get constant speed of light .. and end up with SR. There is more than one logically consistent path to SR .. which is as one would expect for a consistent model.
From: Sue... on 8 Apr 2010 00:58 On Apr 8, 12:29 am, Ste <ste_ro...(a)hotmail.com> wrote: [...] > > > And an observer in the ladder frame who is determining if the pole fits > > within. > > No, we're not talking about any observers. The electromagnetic (light) force is about 100,000,000,000,000,000,000,000,000,000,000 times greater than the gravitational force of our planet. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elefor.html When one charged particle *observes* another charged particle, as in an accelerator they MOVE whether humans are watching or not. This is where SR finds wide application because the preferred frame is not an issue. No philosophy required. Sue...
From: jem on 8 Apr 2010 08:53 Edward Green wrote: > On Apr 7, 3:01 am, Ste <ste_ro...(a)hotmail.com> wrote: > > <...> > >> The fact that I can discuss all these examples, and not get a response >> along the lines of "Yes, I know exactly what you mean Steven, and >> you're quite right about how you describe these effects/scenarios. But >> with SR, there is more, on top of those effects you've already >> described, and it works like this ...", and for no one to be able to >> give an explanation that incorporates the points already raised and >> which does not resort to simple affirmations of the truth of their >> assertions, leads me to believe that I might be asking the blind to >> lead the blind. > > It's more laziness of thought. That's why jem only hears me repeating > the same point over and over again, obstinantely, whereas I have been > continually refining my arguments. It's the same with you. Once a > person knows how a subject works, on some level, he is loath to devote > time to disecting detailed non-standard arguments. He is simply eager > to explain his understanding. > That's it, Green, join this ingrate loon in fantasizing that your ignorance stems from the poor (pro-bono) guidance that's been inflicted on you rather than from your own incorrigibility. You were shown logical proof that Relativity's ideal clocks don't run slow, Green, and no argument refinement is going to negate that.
From: PD on 8 Apr 2010 09:44 On Apr 7, 9:04 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 7 Apr, 23:08, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 7, 4:57 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 7 Apr, 16:57, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 6, 7:12 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > We've had this one before Paul. No experiment of this kind (i.e. > > > > > trying to confine objects moving at relativistic speeds) has ever been > > > > > performed. I even gave sources last time for this statement. > > > > > That is simply not true. At RHIC, for example, where nucleus-nucleus > > > > collisions are done, the density of the quarks and gluons goes up > > > > precisely because of this Lorentz contraction. The nucleus is > > > > "squashed" and the density goes up. This is essential to both the > > > > design and the operation of this multimillion dollar facility. > > > > > Furthermore, secondary particle emission from particle collisions have > > > > been done in both fixed target and collider facilities. Under both > > > > circumstances, relativity predicts the uniform distribution of those > > > > secondaries according to a variable called rapidity. In experiments, > > > > calorimeters are then arranged around the collision point and > > > > segmented in regular rapidity bins. Naturally, because the two > > > > experiments are viewing the same collisions from two different > > > > reference frames, the length binning for equal rapidity bins is > > > > considerably different, precisely because of Lorentz contraction. > > > > Thus, the distribution by rapidity, as shown by the particle deposits > > > > in the calorimeter, is an indirect but definitive check on Lorentz > > > > contraction. Experimentally, the match-up is exquisite. > > > > > It's unfortunate that your web references are not accurate on this > > > > score, and have led you to the impression that Lorentz contraction is > > > > all hypothetical and without experimental support. I will just > > > > attribute this to the lack of depth of experimental information you've > > > > been able to lay your hands on. > > > > I really don't understand enough about how these machines work, and > > > almost certainly never will, so it's pointless me attempting to > > > reconcile what you say. All I will repeat is that a number of > > > scientific sources, including a number of published scientific papers, > > > have insisted that there has been no direct measurement of a physical > > > length contraction. > > > "Direct" is perhaps the key word. It is unfortunate that those papers > > led you to the conclusion that it has not been experimentally verified > > at all. I take no responsibility for confusion on your part that stems > > from the limited selection of material you choose to read. > > Paul, I was quite clear, and was even clearer on previous occasions: > there is no direct evidence. Quite simply, there have been no > experiments where an object of a significant length has been > accelerated and then a physical confinement attempted, with the > outcome that if the object had not contracted, either the setup would > noticably explode or it would be simply impossible to "shut the doors > properly". That's all well and good, but of little practical relevance. "Gedankens" are not aimed to represent real experiments. Real experiments are often indirect for a variety of reasons, including reduction or accurate accounting of systematic errors. Experimental design can therefore appear to be arcane to the novice hobbyist, and amateurs will often ask why it is that a simple and direct experimental expression would not be the best. Here, there is no substitute for practical training in experimental methodology, and there is no "simple recipe" by which this can be explained. Nevertheless, a principle can be tested by an experimental setup that looks nothing at all like the set-up in the gedanken, and indeed has been -- amply. > > I hadn't been led to believe anything except that the kind of > experiment I describe above (in other words, one corresponding to the > ladder and barn scenario) has not been performed. > > > > And indeed, whether there is experimental evidence > > > or not, I still have not heard any compelling *explanation* for how > > > two objects could each physically contract to a smaller size relative > > > to the other. > > > The definition of length is completely reliant on establishing > > simultaneity. > > Since simultaneity is frame-dependent, it is no wonder that length is > > frame-dependent. > > Indeed. Except I've previously asked for simultaneity to be defined in > a frame-independent manner - in the same way we talk of the "source > frequency" in a frame independent way, instead of talking about the > frame dependent "received frequency" This is a little like asking for "stationary" to be defined in a frame- independent manner. What makes you think that such a thing even makes physical sense, other than a profound desire on your part that it be so? > > > > > > > > But as I've said previously, even if this *is* what we would "see", > > > > > seeing is not necessarily believing. > > > > > And this is what I'm telling you is a bad policy in science. If > > > > experiment comes in conflict with common sense -- that is, if what you > > > > see is in conflict with what you understand -- then it is common sense > > > > that should properly give way. I understand fully that you say you > > > > just don't operate that way, and don't see why you should have to. > > > > That's just absurd Paul. Insofar as you're contradicting that "seeing > > > is not necessarily believing", your prescriptions would be a recipe > > > for the trite regurgitation of observations, without any deeper > > > understanding at all. If all we ever had to do in science was observe, > > > and not interpret, then one wonders why it has taken so long to get > > > this far. > > > You have always maintained that there are always multiple > > interpretations, multiple explanations that would apply to the same > > set of data. > > I don't maintain that all are true (only one explanation can be true), > but I concede that the limited data often admits more than one > interpretation. > > > While this may be so in some limited sense, it is the > > burden of the proposer of an interpretation to demonstrate that it is > > the case with his own, complete with quantitative support. > > I'm not going back to discussions about the scientific method or 'on > whom the burden of proof is placed'. > > > Furthermore, it has ALWAYS been the case that there can be isolated a > > place where two different interpretations make DIFFERENT predictions > > about what will be observed under certain circumstances. That, then, > > is the place where the next experimental test is focused. This is > > GUARANTEED to eliminate one or the other of the interpretations, and > > this is how scientific progress is made. > > Who cares? You talk about testing as though every single debate ends > in the parties saying "to the laboratory!" to test the theory. Exactly! That's how science works! > And > anyway like I say, I'm not returning to a debate about the scientific > method.
From: PD on 8 Apr 2010 09:45
On Apr 7, 9:22 pm, "Inertial" <relativ...(a)rest.com> wrote: > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > news:45bff01f-f153-402b-a75b-fa56ccb7a069(a)y17g2000yqd.googlegroups.com... > > > > > On 7 Apr, 23:08, PD <thedraperfam...(a)gmail.com> wrote: > >> On Apr 7, 4:57 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > >> > On 7 Apr, 16:57, PD <thedraperfam...(a)gmail.com> wrote: > > >> > > On Apr 6, 7:12 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > >> > > > We've had this one before Paul. No experiment of this kind (i.e. > >> > > > trying to confine objects moving at relativistic speeds) has ever > >> > > > been > >> > > > performed. I even gave sources last time for this statement. > > >> > > That is simply not true. At RHIC, for example, where nucleus-nucleus > >> > > collisions are done, the density of the quarks and gluons goes up > >> > > precisely because of this Lorentz contraction. The nucleus is > >> > > "squashed" and the density goes up. This is essential to both the > >> > > design and the operation of this multimillion dollar facility. > > >> > > Furthermore, secondary particle emission from particle collisions > >> > > have > >> > > been done in both fixed target and collider facilities. Under both > >> > > circumstances, relativity predicts the uniform distribution of those > >> > > secondaries according to a variable called rapidity. In experiments, > >> > > calorimeters are then arranged around the collision point and > >> > > segmented in regular rapidity bins. Naturally, because the two > >> > > experiments are viewing the same collisions from two different > >> > > reference frames, the length binning for equal rapidity bins is > >> > > considerably different, precisely because of Lorentz contraction. > >> > > Thus, the distribution by rapidity, as shown by the particle deposits > >> > > in the calorimeter, is an indirect but definitive check on Lorentz > >> > > contraction. Experimentally, the match-up is exquisite. > > >> > > It's unfortunate that your web references are not accurate on this > >> > > score, and have led you to the impression that Lorentz contraction is > >> > > all hypothetical and without experimental support. I will just > >> > > attribute this to the lack of depth of experimental information > >> > > you've > >> > > been able to lay your hands on. > > >> > I really don't understand enough about how these machines work, and > >> > almost certainly never will, so it's pointless me attempting to > >> > reconcile what you say. All I will repeat is that a number of > >> > scientific sources, including a number of published scientific papers, > >> > have insisted that there has been no direct measurement of a physical > >> > length contraction. > > >> "Direct" is perhaps the key word. It is unfortunate that those papers > >> led you to the conclusion that it has not been experimentally verified > >> at all. I take no responsibility for confusion on your part that stems > >> from the limited selection of material you choose to read. > > > Paul, I was quite clear, and was even clearer on previous occasions: > > there is no direct evidence. Quite simply, there have been no > > experiments where an object of a significant length has been > > accelerated and then a physical confinement attempted, with the > > outcome that if the object had not contracted, either the setup would > > noticably explode or it would be simply impossible to "shut the doors > > properly". > > > I hadn't been led to believe anything except that the kind of > > experiment I describe above (in other words, one corresponding to the > > ladder and barn scenario) has not been performed. > > >> > And indeed, whether there is experimental evidence > >> > or not, I still have not heard any compelling *explanation* for how > >> > two objects could each physically contract to a smaller size relative > >> > to the other. > > >> The definition of length is completely reliant on establishing > >> simultaneity. > >> Since simultaneity is frame-dependent, it is no wonder that length is > >> frame-dependent. > > > Indeed. Except I've previously asked for simultaneity to be defined in > > a frame-independent manner - > > It can't be. It is a frame dependent notion. Just like velocity cannot be > expressed in a frame independent manner. > > Now .. you CAN express intervals between events in a frame independent way. And Ste, just to do you the courtesy here, "interval" is a physics jargon term with a very specific meaning. > But that is a combination of durations and distances. if you are talking > about just distance (or length) or just time duration, then they are frame > dependent. > > It is a bit like looking at a pair of objects, A and B. Consider the > coordinates of B wrt a set of orthogonal axes centered around A. You will > get different x, y and z coordinates depending on how you orient the axes.. > ie they are frame dependent. However, the sum of the squares of the x, y > and z values will be the same, regardless of the choice of orientation of > axes. |