Known physics defeated by simple puzzle?
in [Relativity]
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From: Ste on 7 Apr 2010 17:27 On 7 Apr, 16:21, Edward Green <spamspamsp...(a)netzero.com> 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. Indeed, although I dare say no one here does "explain" their understanding, they merely assert it.
From: PD on 7 Apr 2010 17:35 On Apr 7, 4:27 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 7 Apr, 16:21, Edward Green <spamspamsp...(a)netzero.com> 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. > > Indeed, although I dare say no one here does "explain" their > understanding, they merely assert it. While giving you references to more appropriate materials where explanations can be found, which you in turn decline. And in fact, I dare say that you yourself note the fact that people here do decline to explain their understanding to your satisfaction, while refusing to acknowledge the reasons WHY they have declined to explain it. So it appears you're at least as guilty of pointing to a fact without trying to understand the reasons for that fact.
From: Ste on 7 Apr 2010 17:39 On 7 Apr, 20:57, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > On 7 abr, 14:47, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > On 7 Apr, 14:03, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > > > > On 7 abr, 03:01, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > On 7 Apr, 05:08, "Inertial" <relativ...(a)rest.com> wrote: > > > > > > yes .. just as we would if we said that the barn-frame observer says the > > > > > pole both fits and doesn't. But, despite you obfuscation and trying to > > > > > distract from what is actually being discussed .. that is not the case > > > > > It's not obfuscation. My arguments are perfectly reasonable. And my > > > > question is this: "does the ladder fit with both doors shut, or not?". > > > > It cannot fit and not fit at the same time. There are only two > > > > objects, ladder and barn. You can't say "according to the barn, it > > > > fits, but according to the ladder, it doesn't", because then you have > > > > two objects that disagree about their relationship with each other, > > > > and indeed make mutually exclusive and contradictory statements about > > > > their relationship.. > > > > Again, your problem (as anybody else here and everywhere clearly > > > understand the gedanken) is that you misunderstand basic physics. "A > > > nuclear blast happens" is the description of an EVENT. when you affirm > > > "It cannot fit and not fit at the same time" you are clearly wrongly > > > reading and understanding the gedanken. For it is quite clear that, > > > from the point of view of the 20 meters pole, it is impossible that it > > > fits inside a 4.37 meters barn. You see, the relevant events, which > > > have to be consistent, are the barn doors closing and opening. In the > > > barn frame of reference (FOR), both barn doors close at the same time > > > and they open at the same time (they are closed for 1 nanosecond). In > > > that condition the contracted 8.37 meters pole is, for a brief lapse > > > of time, inside a closed 10 meters barn. > > > In the pole FOR, the 20 meters pole sees the barn approaching at 0.9c > > > and the back door of the 4.37 meters barn closes and opens, just a > > > brief instant of time BEFORE the front of the pole reaches that > > > location (the 20 meters pole is at that time 4.37 meters inside the > > > barn). After that, the 20 meter pole sees the 4.37 meters barn front > > > door closing and opening, just a brief instant of time AFTER the back > > > of the pole just passed through that location (the 20 meters pole has > > > at that time 15.63 meters of its length outside the barn and its back > > > 4.37 meters inside the barn. > > > In both FOR, the 10 meter barn doors closed and opened and the 20 > > > meters pole did not touch any part of the barn. > > > Nice and easy. > > > Miguel, you seem to think that I don't properly understand the ladder > > and barn paradox. Let me correct you, I understand it completely. I > > can even tell you what would happen, working within the same tenets, > > if with careful timing you sent in *two* ladders in *opposite* > > directions, and shut the doors simultaneously (according to the barn > > frame) so as to contain both ladders for an instant with an > > interference fit. > > > What I'm questioning is whether this "paradox" actually reflects > > reality at all. It is easy to conceive of mathematical models that are > > internally consistent, ostensibly fit the existing evidence, but have > > no basis in reality - mainstream economics abounds with such models > > (and is widely regarded as being empirically discredited, and the > > maths regarded as obfuscatory). > > > That leads on to my real question here. I'm not interested in being > > told *what* SR predicts - which is what you've done here again for the > > umpteenth time. I'm interesting in an explanation of *why* these > > predictions would be what they are. > > > To go back to the audio analogy again, a trivially easy equation > > determines *what* audio Doppler shift you will observe, but it does > > not explain *why*. Indeed, the equations in audio Doppler do not even > > tell you whether the source frequency really changes or not. To > > explain *how* audio Doppler works, and to rule out the assertion that > > the source frequency "really" changes, involves an awareness of each > > step in which mechanical energy is transmitted through air to the > > receiver. > > > That's what this discussion is about. Repeating the paradox does not > > help further *explain* the paradox, or answer any of my questions in > > regard of it. When I say "why does the other object always contract", > > I don't expect to be told "because SR says it does" - that is no > > explanation at all. > > > Jesus. > > I doubt that after writing "It cannot fit and not fit at the same > time" you really understand this gedanken at all. It depends what you mean by "understand". If you mean "have grasped its tenets, and can reason the conclusion from those tenets", then I understand it totally. If you mean "accept that length contraction really occurs", then the answer is no. And I suspect at this point the real problem is not my lack of understanding of the paradox, but your lack of understanding of what I mean by "real". > We all understand > that. You don't know what you are talking about and it shows. > When you build a model of the world such as Special Relativity, you > consider some building blocks (the two postulates) and continue from > there. You are really not interested in following that route, You're right. I'm not interested in merely reasoning from the first principles of a particular theory, and then dusting off my hands and patting myself on the back. I'm interested in seeing how this theory actually applies to the real world, and how the conclusions of the theory are to be interpreted in practice. For example, how "length contraction" is to be explained as a matter of practical reality, and not just accepted at face value "because the theory predicts it". Like I said, the equations of audio Doppler predict that the received frequency will change depending on your velocity to the source. But it does not *explain* why this happens, and nor does it state whether the source frequency changes or not. All it describes is what you will observe, without *any* physical explanation at all. One must look *beyond* the mere maths of audio Doppler, in order to *physically explain* the effect. > and you > are just picking some so called "paradoxes" or in your language > "puzzles" to try to attack the model. The truth is that I'm not "attacking" SR - in the sense of saying that it is inapplicable to reality. I'm actually arguing about *how* it applies to reality.
From: Ste on 7 Apr 2010 17:57 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. 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. > > 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.
From: PD on 7 Apr 2010 18:01
On Apr 7, 4:39 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 7 Apr, 20:57, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > > > > > On 7 abr, 14:47, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 7 Apr, 14:03, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > > > > > On 7 abr, 03:01, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > On 7 Apr, 05:08, "Inertial" <relativ...(a)rest.com> wrote: > > > > > > > yes .. just as we would if we said that the barn-frame observer says the > > > > > > pole both fits and doesn't. But, despite you obfuscation and trying to > > > > > > distract from what is actually being discussed .. that is not the case > > > > > > It's not obfuscation. My arguments are perfectly reasonable. And my > > > > > question is this: "does the ladder fit with both doors shut, or not?". > > > > > It cannot fit and not fit at the same time. There are only two > > > > > objects, ladder and barn. You can't say "according to the barn, it > > > > > fits, but according to the ladder, it doesn't", because then you have > > > > > two objects that disagree about their relationship with each other, > > > > > and indeed make mutually exclusive and contradictory statements about > > > > > their relationship.. > > > > > Again, your problem (as anybody else here and everywhere clearly > > > > understand the gedanken) is that you misunderstand basic physics. "A > > > > nuclear blast happens" is the description of an EVENT. when you affirm > > > > "It cannot fit and not fit at the same time" you are clearly wrongly > > > > reading and understanding the gedanken. For it is quite clear that, > > > > from the point of view of the 20 meters pole, it is impossible that it > > > > fits inside a 4.37 meters barn. You see, the relevant events, which > > > > have to be consistent, are the barn doors closing and opening. In the > > > > barn frame of reference (FOR), both barn doors close at the same time > > > > and they open at the same time (they are closed for 1 nanosecond). In > > > > that condition the contracted 8.37 meters pole is, for a brief lapse > > > > of time, inside a closed 10 meters barn. > > > > In the pole FOR, the 20 meters pole sees the barn approaching at 0.9c > > > > and the back door of the 4.37 meters barn closes and opens, just a > > > > brief instant of time BEFORE the front of the pole reaches that > > > > location (the 20 meters pole is at that time 4.37 meters inside the > > > > barn). After that, the 20 meter pole sees the 4.37 meters barn front > > > > door closing and opening, just a brief instant of time AFTER the back > > > > of the pole just passed through that location (the 20 meters pole has > > > > at that time 15.63 meters of its length outside the barn and its back > > > > 4.37 meters inside the barn. > > > > In both FOR, the 10 meter barn doors closed and opened and the 20 > > > > meters pole did not touch any part of the barn. > > > > Nice and easy. > > > > Miguel, you seem to think that I don't properly understand the ladder > > > and barn paradox. Let me correct you, I understand it completely. I > > > can even tell you what would happen, working within the same tenets, > > > if with careful timing you sent in *two* ladders in *opposite* > > > directions, and shut the doors simultaneously (according to the barn > > > frame) so as to contain both ladders for an instant with an > > > interference fit. > > > > What I'm questioning is whether this "paradox" actually reflects > > > reality at all. It is easy to conceive of mathematical models that are > > > internally consistent, ostensibly fit the existing evidence, but have > > > no basis in reality - mainstream economics abounds with such models > > > (and is widely regarded as being empirically discredited, and the > > > maths regarded as obfuscatory). > > > > That leads on to my real question here. I'm not interested in being > > > told *what* SR predicts - which is what you've done here again for the > > > umpteenth time. I'm interesting in an explanation of *why* these > > > predictions would be what they are. > > > > To go back to the audio analogy again, a trivially easy equation > > > determines *what* audio Doppler shift you will observe, but it does > > > not explain *why*. Indeed, the equations in audio Doppler do not even > > > tell you whether the source frequency really changes or not. To > > > explain *how* audio Doppler works, and to rule out the assertion that > > > the source frequency "really" changes, involves an awareness of each > > > step in which mechanical energy is transmitted through air to the > > > receiver. > > > > That's what this discussion is about. Repeating the paradox does not > > > help further *explain* the paradox, or answer any of my questions in > > > regard of it. When I say "why does the other object always contract", > > > I don't expect to be told "because SR says it does" - that is no > > > explanation at all. > > > > Jesus. > > > I doubt that after writing "It cannot fit and not fit at the same > > time" you really understand this gedanken at all. > > It depends what you mean by "understand". If you mean "have grasped > its tenets, and can reason the conclusion from those tenets", then I > understand it totally. If you mean "accept that length contraction > really occurs", then the answer is no. And I suspect at this point the > real problem is not my lack of understanding of the paradox, but your > lack of understanding of what I mean by "real". Real is what can be verified by a measurement. If you believe that reality has certain traits but that those traits are unverifiable through measurement, because the measurement is always obscured, then one has to ask on what basis you would believe reality has those traits in the first place. If you then say, "Because it makes sense to me that it would," then you have simply slipped into subjective solipsism that is divorced from scientific investigation. Democritus believed in atoms and held firmly that some of them were round, some of them were hooked, some were jagged. Of course, he could say why he thought those were so, but there was no way to verify it through a test that would distinguish it from, say, other models. > > > We all understand > > that. You don't know what you are talking about and it shows. > > When you build a model of the world such as Special Relativity, you > > consider some building blocks (the two postulates) and continue from > > there. You are really not interested in following that route, > > You're right. I'm not interested in merely reasoning from the first > principles of a particular theory, and then dusting off my hands and > patting myself on the back. > > I'm interested in seeing how this theory actually applies to the real > world, and how the conclusions of the theory are to be interpreted in > practice. For example, how "length contraction" is to be explained as > a matter of practical reality, and not just accepted at face value > "because the theory predicts it". In terms of practical reality, length contraction applies to cases where there are high speeds involved, typically. Thus the length of the RF cavities in a LINAC changes as the particle accelerates, at a rate that is completely consistent with length contraction. The same goes for where you place a detector to watch a particle decay, because time dilation of a fast moving particle means it will be further away from its creation when it decays than what would be expected from its speed and its rest lifetime. Since the placement is critical for a successful experimental design, its an excellent example of practical application. For a living-room application, color TVs with CRTs are effectively electron accelerators that would get electrons to sufficiently high speed that you'd have to make a relativistic correction to the steering voltage to get the beam to sweep to the correct spot. Again, a practical application. > > Like I said, the equations of audio Doppler predict that the received > frequency will change depending on your velocity to the source. But it > does not *explain* why this happens, and nor does it state whether the > source frequency changes or not. All it describes is what you will > observe, without *any* physical explanation at all. One must look > *beyond* the mere maths of audio Doppler, in order to *physically > explain* the effect. > > > and you > > are just picking some so called "paradoxes" or in your language > > "puzzles" to try to attack the model. > > The truth is that I'm not "attacking" SR - in the sense of saying that > it is inapplicable to reality. I'm actually arguing about *how* it > applies to reality. |