Is Length Contraction in SR physical??
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From: Ste on 8 Feb 2010 22:53 On 8 Feb, 14:22, mpalenik <markpale...(a)gmail.com> wrote: > On Feb 8, 9:10 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > On 8 Feb, 12:46, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > wrote: > > > > We seem to be getting somewhere now. I can basically understand the > > > principle of how that carries out a detection. Now, do you have any > > > data that plots detections and velocities, at different speeds? > > > > ________________________ > > > > "Plots velocities at different speeds"! > > > > ROFL! > > > The velocities of the decay products for different impact speeds, you > > pillock! > > > > The explanation of how the detector works actually explains how energy and > > > direction are determined for several different particle types and classes. > > > And *none* of it relies on shining beams of light at the particles. > > > I never said it did. But in the case of tauons, it does depend on > > measuring the velocities of decay products, so I want to know what > > those velocities are, and how they change with speed. > > Well, you can look up an experimental paper just as well as anyone > else. Why is it up to us to find this for you? I wish I had someone > to run around getting papers for me when I need them. As I explained to Paul Draper, I actually do that sort of thing for people all the time on a variety of subjects, because the whole point of claiming to have knowledge is that you share it. I've personally no idea how particle accelerators work, and so I don't claim to know. If the truth is that you also don't really know the answers to my questions, because you've never worked on a particle accelerator, then that's fair enough, but then perhaps it will be a lesson for you to be a little more modest about your scientific knowledge. As I say, with particle accelerators relying heavily on electromagnetism, I've no doubt that SR has a big application to its workings. The question is whether the scientists who claim to understand SR actually do understand it in a physical way, or whether they have just learned the maths by rote and swallowed the fallacious explanations they've been given for what they observe. And certainly, if the opinions of "experts" here are anything to go by not to mention in the literature, it is clear that most people who have studied physics ill- understand the physical basis of the theories that they have learned.
From: mpalenik on 8 Feb 2010 23:06 On Feb 8, 10:53 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 8 Feb, 14:22, mpalenik <markpale...(a)gmail.com> wrote: > > > > > > > On Feb 8, 9:10 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 8 Feb, 12:46, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > > wrote: > > > > > We seem to be getting somewhere now. I can basically understand the > > > > principle of how that carries out a detection. Now, do you have any > > > > data that plots detections and velocities, at different speeds? > > > > > ________________________ > > > > > "Plots velocities at different speeds"! > > > > > ROFL! > > > > The velocities of the decay products for different impact speeds, you > > > pillock! > > > > > The explanation of how the detector works actually explains how energy and > > > > direction are determined for several different particle types and classes. > > > > And *none* of it relies on shining beams of light at the particles. > > > > I never said it did. But in the case of tauons, it does depend on > > > measuring the velocities of decay products, so I want to know what > > > those velocities are, and how they change with speed. > > > Well, you can look up an experimental paper just as well as anyone > > else. Why is it up to us to find this for you? I wish I had someone > > to run around getting papers for me when I need them. > > As I explained to Paul Draper, I actually do that sort of thing for > people all the time on a variety of subjects, because the whole point > of claiming to have knowledge is that you share it. > I don't have papers with the results of particle accelerator experiments sitting here in front of me. Particle physics isn't even my field (although relativity is still important for many of the calculations that I do)--that doesn't mean I've never studied particle physics at all or that I haven't read papers from the field, though. I could look up a paper for you but then that runs the risk of you saying "no, that's not what I want," and then I would have to look up another, and maybe another, and who knows where it will end. I have don't have the time to run around looking for papers for you. If your wondering, it's not as simple as "here's the tauon decay particle velocity vs. initial velocity curve". You'll need to sift through a lot of data in a lot of papers and I don't have the time to help you do that. You are just as capable of looking up papers as I am. If you want data, here are two good places to start: arxiv and scholar.google.com. There is no simple answer to your questions about data. There is no one graph out there that is going to answer your questions in a simple, easy to interpret way. Nor is there only one particular experiment, like "the tauon decay experiment". If you want to get this kind of data, it's not fair to expect other people to find it for you.
From: artful on 9 Feb 2010 00:02 On Feb 9, 2:53 pm, Ste <ste_ro...(a)hotmail.com> wrote: > The question is whether the scientists who claim to understand SR > actually do understand it in a physical way, or whether they have just > learned the maths by rote and swallowed the fallacious explanations > they've been given for what they observe. Please put forward what explanations of SR you are referring to, and your evidence / logical argument that proves they are fallacious. Please also provide non-fallacious explanations as alternatives.
From: Ste on 9 Feb 2010 00:19 On 8 Feb, 16:20, PD <thedraperfam...(a)gmail.com> wrote: > On Feb 6, 11:33 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > On 7 Feb, 03:54, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Feb 6, 8:52 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > The only thing that is required is to note at the detector X or the > > > > > detector Y whether the signals from the events arrive at the same time > > > > > or at different times. This is a point decision. It is a yes or no > > > > > question. "Signal from A just arrived at X. Did signal from B arrive > > > > > at X at the same time? Yes or no." > > > > > If detection is instantaneous (i.e. if a photon is absorbed > > > > instantaneously), then it is possible for A and B to be simultaneous > > > > according to both X and Y. However, if detection is not instantaneous, > > > > then it is *not* possible. > > > > I didn't say "according to both X and Y". What I said in fact was the > > > opposite. Please reread. > > > What I did say is that X is *right* in concluding that A and B are > > > simultaneous, based on the procedure we established as reliable. > > > But the procedure isn't reliable! I've said that repeatedly. > > It isn't reliable for what? > For driving a consensus between X and Y? Is that a necessary > requirement? Why? > Let's revisit the procedure. > If you were going to try to determine whether two events are > simultaneous, according to a *particular* observer, then our suggested > procedure is as follows: > 1. Position a detector midway between the two events, where "midway" > can be established at any time by directly measuring the length > between the marks left by the events and the mark at the location of > the detector. Let's amend this to say that this can be repeated on two > occasions to determine that the "midway" condition has not changed. > 2. Have the events send a signal known to travel with equal speeds > toward the detector. The equality of the speeds can be established at > any time by reproducing the signal and directly measuring the distance > covered by the signal per unit time. > (Note that (1) and (2) unambiguously determine that the propagation > delay is the same from both events.) > 3. Determine whether the signals from the events arrive at the > detector at the same time or at different times. If the signals arrive > at the same time, then from that information the correct conclusion is > that the original events were simultaneous. If the signals arrive at > different times, then from that information the correct conclusion is > that the original events were not simultaneous. This works only if neither detector is moving. > You agreed earlier that this procedure should be sufficient for > determining the simultaneity of spatially separated events, according > to a particular observer. > > Now you seem not so sure. What's the source of your sudden > reservation? What procedure would you otherwise propose for > determining the simultaneity of two spatially separated events? The source of my reservation is that equidistance cannot be maintained, nor symmetry maintained, over the detection *interval*, if the two detectors are moving relative to each other. Even in an idealised example where reception of the signal at the atomic level occurs instantaneously (and I do not necessarily accept that even this is true), no detection *system* (i.e. real world measurement device) could perform a measurement of equidistance at the same time as measuring the reception of the signal, and therefore no real-world system can produce an observation of simultaneity where the detectors are moving relative to each other. > > > > > Do you agree that those are the right conclusions, based on the yes or > > > > > no question above, and given that the other conditions can be > > > > > established? > > > > > No. I think your mistake is in assuming that both the photon and > > > > detector have an absolutely zero diameter (and therefore detection > > > > occurs as soon as the surface of the zero-diameter objects touch). In > > > > reality, nothing in space will have a diameter of zero. > > > > I don't know why you think diameter has anything to do with it. Note > > > the size of the distance between A and X and between B and X. If a > > > detector is 1.5 mm across, do you think this is going to be a dominant > > > effect? > > > No, I'm talking about the diameter of the photon and the atom. As I > > say, the visualisation I have is somewhat like two bubbles in water, > > and clearly if they are forced together so that they become one > > bubble, that is not an instantaneous process. Certainly, the bubbles > > do not merge merely at the first instant their (idealised spherical) > > surfaces touch - they must be actually forced together until their > > surface tension breaks. > > > Having thought about it for a moment however, I realise that my > > previous argument might not be wholly relevant or may be speculative > > (although it embodies some likely factors that may be relevant in the > > real world). You can theoretically (in particular, in the absence of > > gravity) bring about absorbtion of photons from both events > > simultaneously for both A and B, assuming that the photons and the > > atoms maintain a constant speed as they impact and are absorbed by the > > atom. > > Let me ask you this. If your physical process can be established to > take no more than, say, 2 picoseconds, and the arrival of the signals > at the detectors is seen to be different by at least 2 microseconds, > would it be established that the original signals were not > simultaneous? Yes, *if* the assumption you make is true. Incidentally, does frequency have any effect on the absorbtion time of electromagnetic radiation?
From: Ste on 9 Feb 2010 00:26
On 8 Feb, 16:24, PD <thedraperfam...(a)gmail.com> wrote: > On Feb 6, 11:38 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > In Seto's case, it has more to do with thinking that SR says something > > > it does not. I haven't yet figured out whether you are in the same > > > boat. > > > The only assumptions I make are those that have testable consequences.. > > > Which ones of those do you think I have that you reject? > > > At least one of the assumptions to which I refer is that observation > > reflects reality. > > Science is about relationships between measurable phenomena, that is, > the observed ones. > If you believe science is about "real" properties which are > unmeasurable but are nevertheless there, then I would ask how you > would deduce anything quantitative about them, or in fact how you > would test that your deductions are in fact accurate? Obviously it depends on the issue. What I would say is that my hypothesis about the aether does have a theoretical test. In particular, there should be a particular velocity at which measured time runs fastest, and at all other velocities measured time should run slower. > If you then > claim that it is not necessary to test them, and is only sufficient to > be reasonably certain that one's intuitions about them are correct, > then I can pretty flatly say that what you are talking about no longer > has any resemblance to science. We've discussed the philosophy of science extensively Paul. You have yet to produce any coherent definition of "science" which is constistent with the reality of how it is practiced. |