A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
|
From: Ste on 23 Feb 2010 00:19 On 22 Feb, 14:54, PD <thedraperfam...(a)gmail.com> wrote: > On Feb 21, 4:23 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > On 21 Feb, 21:40, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Feb 20, 9:36 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > On 20 Feb, 05:27, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > > > wrote: > > > > > > If you're suggesting that it's improbable that a theory could work not > > > > > because its premises were correct, but because it simply promoted > > > > > correct behaviours, then wonders why religion has fared so well. In > > > > > any event, I'm willing to accept Feynman's argument, basically that QM > > > > > amounts to a workable mathematical model, and makes no claim to any > > > > > truth more fundamental than that. > > > > > > ________________________________ > > > > > The whole of physics is like that, not just QM. Physics just gives us the > > > > > eqns by which the universe functions. It does not make claim to any more > > > > > truths fundamental than the eqns; the rest is just philosophy. > > > > > > Your problem of course is that you don't understand the eqns, so you don't > > > > > understand physics. > > > > > On the contrary, my problem is that physics seems to have dispensed > > > > with the physical. Yet it is the physical, as opposed to the > > > > mathematical, that I am interested in. That is, the qualitative > > > > physical concepts - what I've referred to as an explanation at the > > > > the "practical-mechanical" level - that would seem to me to > > > > distinguish physics from maths are largely absent, and indeed seem to > > > > be systematically deprecated and devalued. > > > > > And on top of this, there is an ideological arrogance on the part of > > > > many in physics that is distasteful in light of their claims to > > > > "objectivity" and "adherence to scientific principles". > > > > > Indeed, your argument that "physics does not make claim to any truths > > > > more fundamental than the eqns" is, itself, a philosophical position > > > > and a statement of ideology - even though you refer disparagingly to > > > > "the rest" as "just philosophy". > > > > > This ideological position becomes even more detectable in the context > > > > of grandiose claims that "physics gives us the eqns by which the > > > > universe functions". > > > > > Not only is that a total falsehood when interpreted literally and in > > > > the context of history, but moreover I know from the context that you > > > > do not mean "regrettably, physics has only given us the eqns..." or > > > > even "physics has given us the eqns, and I'm unable to say if there is > > > > a more complete description", what you really mean is "these eqns > > > > provide a complete and final description of the physical world, and I > > > > hold that nothing else is relevant to physics and nor am I concerned > > > > with it". > > > > > And what I object to is not the content of these staments, but the > > > > constant concealment of your ideological beliefs beneath allusions to > > > > objectivity and ideological and philosophical independence. > > > > I note with interest that you at one point appeared to be interested > > > in engaging in learning how it is that the speed of light could be the > > > same, regardless of the motion of the source, or how it is that > > > simultaneity could be frame-dependent. But your interest in the > > > physics here quickly waned and you fell back to fussing about the > > > sociology of scientists. What accounts for your short attention span > > > for the physics? Note that in the discussions I was giving you, there > > > was practically no math in favor of presentation of basic physical > > > principles and their conceptual implications. > > > Actually I was still interested in discussing the invariance of 'c', > > and I do still have questions. Unfortunately, both threads appear to > > have been partly taken over by other posters arguing completely > > different points, and much of my own time and attention has once again > > returned to addressing the quips, implicit insults, and general > > "sociological" points raised. > > So let's get back to the physics. > You had an array of sources and detectors. > I suggested that the sources can be something real, like a flashbulb > or a firecracker, which emits a very brief pulse of light in all > directions. > The detectors will be something that triggers when a pulse of light > arrives at the detector. We can use a photodiode or a photomultiplier > tube with hemispherical photocathode if you like. > With this kind of arrangement, it is certainly possible to ask which > detectors will trigger before, at the same time as, or after other > detectors, though that answer may vary from reference frame to > reference frame. > Do you want to ask that question regarding a particular set-up of > detectors and sources? Yes, but I think I'll start another thread when I've had a bit of time to sit down and think about the problem.
From: BURT on 23 Feb 2010 00:32 A frame can travel behind light. Mitch Raemsch
From: mpalenik on 23 Feb 2010 03:02 On Feb 23, 12:16 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 22 Feb, 04:07, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Feb 21, 6:38 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > Hmmm. So there appears to be two models for what has happened in such > > > > > > cases: > > > > > > 1) the student who went through those classes had reason and good > > > > > > sense *stripped* of them to the point where they would believe > > > > > > nonsense, and this result is inherent to the process undergone. > > > > > > 2) the student who went through those classes learned something new, > > > > > > including how to test unambiguously for extra dimensions (regardless > > > > > > whether it has been yet determined by test) and what the motivations > > > > > > for even considering them might be, so that what seems like nonsense > > > > > > to the novice no longer seems like nonsense. > > > > > > I dare say there is a third. The student went into the class without > > > > > having any "good sense" in the first place, and therefore they were > > > > > willing to accept anything that they were told there. > > > > > Thereby implying that those who have expertise in the field are those > > > > who lacked good sense to begin with and whose common feature of > > > > gullibility is the parameter for success in the field. Nice. > > > > I have suggested that this is a third possibility. I also note you > > > read this outside of the qualifying statement I made immediately after > > > the above (now shown further below), the essence of which is to say > > > that the hobble of a purely mathematical approach may be that the > > > maths ends up totally at large, unconstrained by the requirements of > > > (and lacking the further inspiration of) a qualitatively physical > > > explanation. > > > The "may be" could well be a concern of yours, but it does not appear > > to be borne out by fact. As I've repeated to you several times, the > > prevailing theories DO all have underlying physical conceptual > > frameworks. > > They are not all cogs-and-levers of the form that you would like to > > see, but that does not mean that they are purely mathematical > > exercises. > > It's remarkable that you have this apparent false dichotomy of cogs- > > and-levers and, failing that, purely mathematics. > > I haven't really argued such a dichotomy. What I have said is that > things like "backwards causation" are just totally irreconcilable with > any physical reality as I know it, and it was you who then > characterised this as "cogs and levers" and small-minded. And as I've > said, repeatedly, what you call my "cogs and levers" approach is far > more flexible than your caricature would imply. > > > > > > > > > Conversely, you also imply that those who have good sense to begin > > > > with, and who do not suffer from gullibility, are naturally OUT OF the > > > > field. > > > > I am suggesting that those in the field may be selected by factors > > > that are not obvious, but which undermine their collective claims to > > > credibility, reliability, and objectivity on the broader questions of > > > their field of study. > > > As you wish. Basically, you're saying that you don't believe anything > > that group of people put forward, because you can convince yourself > > that any such group of people self-select to be nonsense-generators > > (especially since they disagree with you). This puts yourself in > > admirable position of being impervious to becoming convinced that > > you're wrong, at least at the hands of any representative of this > > group of people. > > You're characterising my position as being far more hardline than it > is. What I'm saying, at it's most simple, is that I'm not willing to > simply take the word of "authority". Separate from that, I've also > made it clear that I have certain axioms that are not in principle > unquestionable or irrefutable, but which would require such an > overwhelming amount of evidence to overturn that they are, in > practice, probably irrefutable. > > > > > > > > Incidentally, I once heard a fictional story that a mathematician and > > > a gangster are both witnessing a coin toss. The coin shows heads ten > > > times in a row. They are asked to estimate the probability of the next > > > result. The gangster says "almost certainly heads". The mathematician > > > guesses the gangster's logic, laughs, and says "an equal probability > > > of heads or tails - the past results do not influence the future > > > probabilities". The gangster suggests "it does if the coin is > > > weighted". And regardless of the true nature of the coin, both gave > > > answers that were heavily contingent on unstated assumptions (most of > > > which will have been wholly implicit and unexamined as far as the > > > conscious mind is concerned), and both raised issues that the other > > > will almost certainly not have considered before giving an answer. > > > Precisely! And you will note that there is an experimental test to > > check which of these two models, including the presumptions of each of > > their models, is at work. Note that it is not possible to determine ON > > THE FACE of it > > I'll forgive this atrocious pun. ;) > > > which of these two models is correct or even more > > likely, even if you have a hunch or a personal preference for one. But > > both the gangster and the mathematician have put forward models with a > > testable prediction. In particular, if you tossed it another 100 > > times, the two theories would have remarkably different predictions, > > and the *coin itself* will tell you which of the two models is a > > better description of it. > > That's not true. A further 100 tosses would not discern definitively > between the two theories, for the outcome would still be technically > consistent with either theory. In fact, though, you can calculate the probability that either hypothesis is correct if the coin toss comes out a certain way after 100 tosses. 100% heads, for example, would put you well past a 95% confidence interval. And in fact, when experimentalists publish their data, they do also publish such confidence intervals. > > > Notice how different this approach is from sitting back and trying to > > decide whether mathematicians (or gangsters) are groups of people who > > self-select themselves into delusions, and therefore their models are > > not to be trusted. Why do that kind of nonsense, when you can simply > > ask the coin to show its colors? > > Because in the real world it is not simply a case of flipping the coin > an infinite number of times. Let's face it, we both submit to evidence > - that cannot be the difference between us. Actually, you tend to hand-wave away any evidence you don't like as 100 years of bad experiments, as in the case of the Michaelson Morely experiment and others like it with similar, albiet more refined, steups, which you were insisting had problems for a long time. Perhaps the difference is, we understand the experimental evidence and you don't. > > > > > > > > > > Of course I'd rather avoid saying that these students have "no sense". > > > > > I'm much more willing to believe that they are simply not concerned > > > > > with a practical-mechanical explanation, possibly because beforehand > > > > > they don't have any well-developed intuitions for it, and secondly > > > > > it's vogue in science at the moment to emphasise purely mathematical > > > > > explanations over practical-mechanical explanations. > > > > > > > Now, how might one test which of these two claims is what has really > > > > > > happened? > > > > > > > Let me suggest one. If (1) were the case, then because of the inherent > > > > > > flaw in the process, then it would have likely been observed up to > > > > > > this point that there is a whole class of former students who have > > > > > > come to believe some principle that is objectively falsifiable. It > > > > > > would be falsifiable perhaps by the construction of a whole class of > > > > > > devices whose design is based on that principle and which (because the > > > > > > principle is false) obviously don't work in practice. Perhaps you can > > > > > > point to some cases like that where devices with designs based on > > > > > > relativity or quantum mechanics simply do not work because the > > > > > > principles are wrong. Or is it your claim that all such devices happen > > > > > > to work by accident, even though the design principles are wrong? > > > > > > If you're suggesting that it's improbable that a theory could work not > > > > > because its premises were correct, but because it simply promoted > > > > > correct behaviours, then wonders why religion has fared so well. > > > > > I don't know of any practical, artificially created devices that are > > > > used in everyday life whose designs are based on religious principles. > > > > Do you? > > > > But the form of the question is designed to confirm your > > > preconception. > > > I don't think so. Perhaps if you gave an example from the most recent > > century of physics. > > I'm not arguing that religious principles have been used directly to > create "practical, artificial devices". What I did suggest was that a > theory can work because it promotes correct behaviours, independent of > the truth of its explicit premises. So, for example, praying to Vishnu is a correct behavior, whether or not he exists? <snip> > > > > If we are to judge theories based on their tendency to bring about > > > desirable outcomes (which I think is one of the unspoken assumptions > > > in your question) then it does not seem to me that a theory's premises > > > need to be factually correct; only that it produces the desired > > > outcome. Which is what I said in the first place. > > > Whether a theory's premises are factually correct IS DETERMINED by > > whether it produces accurate predictions of measurements. That's how > > science makes that determination in the first place. > > Not really. Once you factor in technological constraints, margins of > error, empirical constants, domains of applicability, sheer > complexity, implict knowledge, and probably innumerable other issues, > it becomes very difficult to discern whether the explicit body of > knowledge is true or whether it simply produces sufficiently correct > behaviours without there being any truth to its explicit form. > And, if you can disprove a current theory, which means 1) coming up with a theory that does something the old theory can't 2) demonstrate that the new predictions you make are correct If you can supplant an old theory with a new, better one, you can 1) publish it, 2) gain great scientific acclaim, and 3) possibly win a lot of money. If I could disprove Special Relativity, that would be great. I'd get a nobel prize. But there are over 100 years of experiments that need to be explained with any new theory and it needs to have something new that relativity doesn't have. The scientific community and scientific publications aren't afraid of publishing new ideas. Nature even published an article on homeopathy once (with a disclaimer at the beginning) because the experimental setup seemed to be perfect, and yet, it gave these incredible, surprising results, that even after you dilute out all of a solute, water still somehow retains the properties of that solute. This prompted other scientists to try to reproduce those results, and when none could, the original team was investigated, and it turned out there were researchers who were (perhaps by accident) causing errors in the experiment. The reason the scientists here haven't accepted you with open arms isn't because you're preaching something we don't like to hear, it's because: 1) You claimed that over 100 years of experiments are in error without any actual, logical explanation of what that error was 2) You 3) You refuse to do any quantitative predictions, which would immediately tell you whether or not a given modification to a theory is wrong (to use the gravity example, if I said that gravity falls off as 1/r instead of 1/r^2, that would have direct, obvious implications to the real world that would be easily testable/measurable). 4) You immediately assume that because certain physics doesn't work the way *you personally* want it to, that it is because science is run like a religion. That *your personal* philosophies are necessarily the correct ones, and anything that doesn't fit in with *your personal viewpoint* must NECESSARILY mean that science is wrong. 5) It is very clear that you don't have a good understanding of relativity or the concepts behind it. Even simply from the fact that you're incapable of correctly doing the thought experiments that you post here by yourself. It is necessary that you correctly understand a theory before you go around pointing out its flaws. The funny thing is, you accuse so many people of "wrong thinking," because obviously, education must cause wrong thinking, and yet, this is all based on the fact that our thinking does not conform to *your specific thinking*. You never consider that it might be your lack of experience, your lack of education, your lack of knowledge, and your personal inability to recocile certain concepts that's the problem? Instead, it must be that everybody else has the problem. . .
From: PD on 23 Feb 2010 09:55 On Feb 22, 11:19 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 22 Feb, 14:54, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Feb 21, 4:23 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 21 Feb, 21:40, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Feb 20, 9:36 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > On 20 Feb, 05:27, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com..au> > > > > > wrote: > > > > > > > If you're suggesting that it's improbable that a theory could work not > > > > > > because its premises were correct, but because it simply promoted > > > > > > correct behaviours, then wonders why religion has fared so well.. In > > > > > > any event, I'm willing to accept Feynman's argument, basically that QM > > > > > > amounts to a workable mathematical model, and makes no claim to any > > > > > > truth more fundamental than that. > > > > > > > ________________________________ > > > > > > The whole of physics is like that, not just QM. Physics just gives us the > > > > > > eqns by which the universe functions. It does not make claim to any more > > > > > > truths fundamental than the eqns; the rest is just philosophy. > > > > > > > Your problem of course is that you don't understand the eqns, so you don't > > > > > > understand physics. > > > > > > On the contrary, my problem is that physics seems to have dispensed > > > > > with the physical. Yet it is the physical, as opposed to the > > > > > mathematical, that I am interested in. That is, the qualitative > > > > > physical concepts - what I've referred to as an explanation at the > > > > > the "practical-mechanical" level - that would seem to me to > > > > > distinguish physics from maths are largely absent, and indeed seem to > > > > > be systematically deprecated and devalued. > > > > > > And on top of this, there is an ideological arrogance on the part of > > > > > many in physics that is distasteful in light of their claims to > > > > > "objectivity" and "adherence to scientific principles". > > > > > > Indeed, your argument that "physics does not make claim to any truths > > > > > more fundamental than the eqns" is, itself, a philosophical position > > > > > and a statement of ideology - even though you refer disparagingly to > > > > > "the rest" as "just philosophy". > > > > > > This ideological position becomes even more detectable in the context > > > > > of grandiose claims that "physics gives us the eqns by which the > > > > > universe functions". > > > > > > Not only is that a total falsehood when interpreted literally and in > > > > > the context of history, but moreover I know from the context that you > > > > > do not mean "regrettably, physics has only given us the eqns..." or > > > > > even "physics has given us the eqns, and I'm unable to say if there is > > > > > a more complete description", what you really mean is "these eqns > > > > > provide a complete and final description of the physical world, and I > > > > > hold that nothing else is relevant to physics and nor am I concerned > > > > > with it". > > > > > > And what I object to is not the content of these staments, but the > > > > > constant concealment of your ideological beliefs beneath allusions to > > > > > objectivity and ideological and philosophical independence. > > > > > I note with interest that you at one point appeared to be interested > > > > in engaging in learning how it is that the speed of light could be the > > > > same, regardless of the motion of the source, or how it is that > > > > simultaneity could be frame-dependent. But your interest in the > > > > physics here quickly waned and you fell back to fussing about the > > > > sociology of scientists. What accounts for your short attention span > > > > for the physics? Note that in the discussions I was giving you, there > > > > was practically no math in favor of presentation of basic physical > > > > principles and their conceptual implications. > > > > Actually I was still interested in discussing the invariance of 'c', > > > and I do still have questions. Unfortunately, both threads appear to > > > have been partly taken over by other posters arguing completely > > > different points, and much of my own time and attention has once again > > > returned to addressing the quips, implicit insults, and general > > > "sociological" points raised. > > > So let's get back to the physics. > > You had an array of sources and detectors. > > I suggested that the sources can be something real, like a flashbulb > > or a firecracker, which emits a very brief pulse of light in all > > directions. > > The detectors will be something that triggers when a pulse of light > > arrives at the detector. We can use a photodiode or a photomultiplier > > tube with hemispherical photocathode if you like. > > With this kind of arrangement, it is certainly possible to ask which > > detectors will trigger before, at the same time as, or after other > > detectors, though that answer may vary from reference frame to > > reference frame. > > Do you want to ask that question regarding a particular set-up of > > detectors and sources? > > Yes, but I think I'll start another thread when I've had a bit of time > to sit down and think about the problem. As you wish. You may find it more constructive just talking through the problem with someone rather than trying to think it through yourself, though. Just sayin'.
From: Paul Stowe on 23 Feb 2010 10:51
On Feb 23, 12:02 am, mpalenik <markpale...(a)gmail.com> wrote: > On Feb 23, 12:16 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > Notice how different this approach is from sitting back and trying to > > > decide whether mathematicians (or gangsters) are groups of people who > > > self-select themselves into delusions, and therefore their models are > > > not to be trusted. Why do that kind of nonsense, when you can simply > > > ask the coin to show its colors? > > > Because in the real world it is not simply a case of flipping the coin > > an infinite number of times. Let's face it, we both submit to evidence > > - that cannot be the difference between us. > > Actually, you tend to hand-wave away any evidence you don't like as > 100 years of bad experiments, as in the case of the Michaelson Morely > experiment and others like it with similar, albiet more refined, > steups, which you were insisting had problems for a long time. > Perhaps the difference is, we understand the experimental evidence and > you don't. Where did he say the MMX was a bad experiment? IMO no 'experiment' is either good or bad, it's simply data. What's bad is predetermining HOW one will interpret data. Tom Robert hss a point (pointing out the 'bad' in science) when claims you cannot DO an experiment without first knowing (have predetermined) what you're looking for. That's plain BS and exemplifies the worse of science. Many times experimental data or observations can fit several explanations but, if one has predetermined HOW they want to make it fit their worldview those others aren't even considered. In fact, the MMX is a great experiment and it points out this fact. Scientist of that period had the mindset that solid matter could not be affected by simple motion because it was too rigid. They 'preconcieved' what the results MUST BE. To this very day that preconception is clung to by many. > > > I don't think so. Perhaps if you gave an example from the most recent > > > century of physics. > > > I'm not arguing that religious principles have been used directly to > > create "practical, artificial devices". What I did suggest was that a > > theory can work because it promotes correct behaviors, independent of > > the truth of its explicit premises. > > So, for example, praying to Vishnu is a correct behavior, whether or > not he exists? Example in science, virual particles... > > > Whether a theory's premises are factually correct IS DETERMINED by > > > whether it produces accurate predictions of measurements. That's how > > > science makes that determination in the first place. > > > Not really. Once you factor in technological constraints, margins of > > error, empirical constants, domains of applicability, sheer > > complexity, implict knowledge, and probably innumerable other issues, > > it becomes very difficult to discern whether the explicit body of > > knowledge is true or whether it simply produces sufficiently correct > > behaviours without there being any truth to its explicit form. > > And, if you can disprove a current theory, which means > 1) coming up with a theory that does something the old theory can't > 2) demonstrate that the new predictions you make are correct This is BS. That is not the only criteria, and you should know this. > If you can supplant an old theory with a new, better one, you can 1) > publish it, 2) gain great scientific acclaim, and 3) possibly win a > lot of money. None of which is the actual persuit of scientific knowledge. In fact, it reflects on all that is 'bad' in the practice of modern science. 1) gate keeping, 2) Pursuit of celebrity status, 3) seeking/expecting capitalist gains from the process. In the ideal (alturistic) the pursuit knowledge and its disimination was a goal unto itself. But, knowledge is power, and some types of knowledge leads to dangerous venues, as such, such knowledge and it desimination must be regulated and controlled. Thus the need for gatekeepers and controlling what is freely published. If you think otherwise, you're living in fantasyland... > If I could disprove Special Relativity, that would be great. I'd get > a nobel prize. But there are over 100 years of experiments that need > to be explained with any new theory and it needs to have something new > that relativity doesn't have. Like how the system would behave at superluminal velocities, right. BTW, GR surplanted SR just like SR surplant Newton. > The scientific community and scientific publications aren't afraid of > publishing new ideas. Nature even published an article on homeopathy > once (with a disclaimer at the beginning) because the experimental > setup seemed to be perfect, and yet, it gave these incredible, > surprising results, that even after you dilute out all of a solute, > water still somehow retains the properties of that solute. This > prompted other scientists to try to reproduce those results, and when > none could, the original team was investigated, and it turned out > there were researchers who were (perhaps by accident) causing errors > in the experiment. > > The reason the scientists here haven't accepted you with open arms > isn't because you're preaching something we don't like to hear, it's > because: > 1) You claimed that over 100 years of experiments are in error without > any actual, logical explanation of what that error was > 2) You > 3) You refuse to do any quantitative predictions, which would > immediately tell you whether or not a given modification to a theory > is wrong (to use the gravity example, if I said that gravity falls off > as 1/r instead of 1/r^2, that would have direct, obvious implications > to the real world that would be easily testable/measurable). > 4) You immediately assume that because certain physics doesn't work > the way *you personally* want it to, that it is because science is run > like a religion. That *your personal* philosophies are necessarily > the correct ones, and anything that doesn't fit in with *your personal > viewpoint* must NECESSARILY mean that science is wrong. > 5) It is very clear that you don't have a good understanding of > relativity or the concepts behind it. Even simply from the fact that > you're incapable of correctly doing the thought experiments that you > post here by yourself. It is necessary that you correctly understand > a theory before you go around pointing out its flaws. And there are elements of models than cannot be readily discriminated, like, for example, whether the gravitational constant is, in fact constant throughout space, or, if above a certain mass, the gravitational force remains strictly proportional to the masses, ... etc., etc., etc. > The funny thing is, you accuse so many people of "wrong thinking," > because obviously, education must cause wrong thinking, and yet, this > is all based on the fact that our thinking does not conform to *your > specific thinking*. You never consider that it might be your lack of > experience, your lack of education, your lack of knowledge, and your > personal inability to recocile certain concepts that's the problem? > Instead, it must be that everybody else has the problem. . . To me, personally, wrong thinking is exemplified by extreme cynicism and closed mindedness. An in today's world of scientist this appears to be the norm. Like Feynman once said, what do you care what other people think? Paul Stowe |