Known physics defeated by simple puzzle?
in [Relativity]
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From: spudnik on 7 Apr 2010 14:36 well, "fits in the barn" or "go/no-go" is invariant to refernce frames; apparent simultaneity with other events, qua some other frame, is another matter. and, the dead twin might be the older one. thus: nah, it's just some math; the French use it, in place of "centroid" or "center of gravity" (actually, "isobarycentre"). and, remember, antimatter is affected, in the same way as matter, by light waves; such a realization kind-of puts the question too the whole idea of a "photon;" eh? nor is there necessarily any need for "negative energy!" > A barycenter is a zone or volume of negative gravity. --Light: A History! http://wlym.com http://21stcenturysciencetech.com http://white-smoke.wetpaint.com
From: spudnik on 7 Apr 2010 14:37 hay is for horses ... and sleeping! thus: well, "fits in the barn" or "go/no-go" is invariant to refernce frames; apparent simultaneity with other events, qua some other frame, is another matter. and, the dead twin might be the older one. thus: nah, it's just some math; the French use it, in place of "centroid" or "center of gravity" (actually, "isobarycentre"). and, remember, antimatter is affected, in the same way as matter, by light waves; such a realization kind-of puts the question too the whole idea of a "photon;" eh? nor is there necessarily any need for "negative energy!" > A barycenter is a zone or volume of negative gravity. --Light: A History! http://wlym.com http://21stcenturysciencetech.com http://white-smoke.wetpaint.com
From: Ste on 7 Apr 2010 14:47 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.
From: PD on 7 Apr 2010 15:31 On Apr 7, 1:47 pm, 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). It is virtually unheard of in physics, despite your experience with economics, that a model is internally consistent, fits the existing evidence, and *continues to make accurate predictions of new measurements*, and still has no basis in reality. In physics, a model that is internally consistent and has a good fit to all known and ongoing measurements is a GOOD model by operational assumption, until such time as it begins to fail having a good fit to measurements. I notice your statement that there are many economic models that fit the existing evidence and yet are empirically discredited. You can imagine my confusion about that. > > 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. This will ultimately boil down to a couple of statements: 1. Maxwell's laws of electromagnetism, as well as other physical laws like them, work to accurately model reality, as evidenced by their fit to experimental data. 2. Physical laws all have the same form in any inertial reference frame. Now, getting from these two statements to the conclusions of the ladder and pole situation -- or for that matter, situations that have been directly and unambiguously tested -- requires pages and pages of exposition if done in words. It will take much less if done with algebra. > > 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.
From: paparios on 7 Apr 2010 15:57
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. 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, and you are just picking some so called "paradoxes" or in your language "puzzles" to try to attack the model. The response to that attitude is very old in this group and is due to Tom Roberts: History also shows that nobody has ever developed a new and useful theory without being familiar with the then-current theories and experiments. That's why the idiots and crackpots around here are so pathetic: if they truly wanted to make a contribution, they would be seriously STUDYING the current theories and experimental record, and trying to extend one or the other Miguel Rios |