Known physics defeated by simple puzzle?
in [Relativity]
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From: paparios on 12 Apr 2010 13:25 On 12 abr, 12:12, Ste <ste_ro...(a)hotmail.com> wrote: > On 12 Apr, 16:41, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > wrote: > > > > and the speed of propagation of signal v is something that is > > > determined in separate measurements. > > > But the speed of signal propagation may itself be dependent on the > > relative velocity (through some unknown dynamic in the electromagnetic > > interaction). Prima facie, it may be difficult to extricate that > > variable from other confounding variables. > > > _________________________________________ > > It has been explained to you about 1,327 times that the speed of light is > > independent of the speed of the sender; this is a fundamental postulate of > > SR, is predicted by Maxwell's equations, and is massively proved > > experimentally. Are you (a) so stupid that you haven't understood this yet, > > or (b) saying SR is wrong ? > > No, I'm saying that SR may well be quantifying this variable, but by > attributing it to a relativity of simultaneity rather than a variance > in the speed of propagation. But as I say, I haven't quite got to > grips with SR yet or how simultaneity changes for the clocks in my > example, so let's concentrate on that first before going off on > tangents discussing ideas that are purely speculative and which are > not based on a complete understanding of SR. This response is a textbook example of a troll behavior... Miguel Rios
From: PD on 12 Apr 2010 13:55 On Apr 12, 10:14 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 12 Apr, 15:30, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 12, 9:10 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > >> What depends on velocity and position (from my frame of reference) is how > > > > >> far ahead or behind the reading on a moving clocks is compared to a > > > > >> (synchrnoised with my at-rest clock) stationary clock at the same > > > > >> position > > > > >> as the moving one. > > > > > > Yes, but we don't need to talk about the "same position as the moving > > > > > one", because we're disregarding propagation delays altogether - so > > > > > the separation distance shouldn't have any influence on the result. > > > > > Just making it clear. And that is HOW we can get rid of propagation delays. > > > > That reasoning does not *necessarily* stand up. The propagation delay > > > may be different for a moving object than for a stationary object. > > > You'll have to explain why you think so. > > Well it was only an off-the-cuff thought, not a specific rebuttal. > > > A propagation delay is given > > very simply by t=d/v. The distance d is something that is the same > > whether the source is stationary or moving at the moment of emission, > > Not if the emission is non-instantaneous. If you have a period of > emission, then clearly the start of the emission and end of emission > is 'd' when you have a stationary object, but in the case of a moving > object, if the start of emission is at 'd', then the end isn't at > 'd' (and the converse also). The leading edge is sufficient. You seem to have it fixed in your head that an emission lasts an interval of time, and that entire signal's duration needs to be received in order to measure the time of propagation. Tell me, if you're timing a car in a race, does the whole car have to cross the finish line in order for you to tell me its speed? Practically speaking, the only thing you might desire is that the pulse of light is short compared to the propagation time, although even this is not necessary. A good example of a timing experiment was done with the photons emitted from neutral pion decay, where the pion is the moving source. The experiment was performed by Filippas and Fox. And in this particular case, you'll recall that a photon is observationally as an instantaneous (that is, imperceptibly short) delivery of momentum and energy at the detector. There is no pulse width for a photon, other than what would come from the Heisenberg uncertainty principle. > > > and the speed of propagation of signal v is something that is > > determined in separate measurements. > > But the speed of signal propagation may itself be dependent on the > relative velocity (through some unknown dynamic in the electromagnetic > interaction). Prima facie, it may be difficult to extricate that > variable from other confounding variables. As mentioned below, this is ruled out by observation. > > > In the case of light, we know > > from direct measurement that v is independent of source speed and is > > always c (in a vacuum) and c/n (in dielectric environments), and so > > the propagation delay is known to be independent of the speed of the > > source. > > But is it independent of the speed of the receiver? No, and this is also experimentally confirmed. I'm sure you've been given a list of experimental papers that includes these measurements.
From: PD on 12 Apr 2010 13:55 On Apr 12, 10:04 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 12 Apr, 15:12, PD <thedraperfam...(a)gmail.com> wrote: > > > On Apr 12, 2:58 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > and have swallowed various preconceptions > > > > > As you have done regarding physics > > > > I would argue that I haven't swallowed preconceptions. > > > On the contrary, you have freely admitting holding to certain axioms > > that you are not willing to reconsider, such as strictly > > deterministic, time-ordered causality. To you, it is inconceivable > > that a self-respecting scientist would hold it suspect. > > I think it is inconceivable that the science mainstream would take it > seriously without overcoming the serious logical and philosophical > issues with the concept. But that's you. Your incredulity may have something to do with lack of familiarity with the subject matter. Indeed, it might do you well to 1) Make the observation of fact that it IS treated seriously in the scientific mainstream; 2) Inquire why that might be, without first presupposing that this observation is accounted for by brainwashing and submission to authority; 3) Ask whether and how the serious logical and philosophical issues have been dealt with. > And indeed, I can tolerate a plurality of > opinion, but it's certainly not something I can imagine taking > seriously.
From: PD on 12 Apr 2010 14:07 On Apr 12, 9:50 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 12 Apr, 15:02, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 11, 10:43 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > Such proponents > > > > > also tend to have a general worldview that is informed entirely by > > > > > their imaginations or naive beliefs, > > > > > ...such as temporally ordered cause and effect between strictly > > > > material agents... > > > > Despite your snipe Paul, there is actually some evidence for this, and > > > as you've conceded before, no experimental evidence against it.' > > > Oh, but there IS evidence against it in some cases. What you insist, > > however, is that the evidence is an illusion of some underlying > > process that is somehow temporally ordered causality that GIVES THE > > APPEARANCE of the violation. > > The evidence that supposedly supports you is very tenuous indeed. Not according to physicists. It's very solid, in fact, repeated in many different, complementary incarnations. > As > I've said, I just don't see how you can distinguish premonition and > cause from cause and effect. > > > This is a little like saying that there is evidence that the Earth is > > only 6600 years old, a creation of God in its present state more or > > less (that evidence being the Bible, an implicitly trustworthy > > source), and there is no evidence that the earth is older than 6600 > > years old. When confronted with geological dating data, one could > > easily argue that God arranged it so that it APPEARS that the earth is > > older than 6600 years old. > > Indeed, so what? This creationist contention is to be distinguished from science. > > > > Even > > > when I questioned you on the issue of premonition and cause, you found > > > it very difficult to explain how it could be experimentally > > > distinguished from cause and effect. > > > As I recall, I gave you a definition of cause and effect, which you > > found too abstract, and that essentially you could not conceive of the > > concepts of cause and effect that did not imply temporal ordering. > > As I recall, I questioned you on how this premonition and cause could > be experimentally distinguished from cause and effect. Because the independent variable is altered temporally after the dependent variable. > > > > Incidentally, I recall that our definition of "material" is different > > > - remember, my defintion includes what you call the "immaterial". > > > Yes, indeed, and I've used the term (and defined it for you) in the > > manner that word is used in physics. Furthermore, you may yourself > > find it amusing that your definition of material includes its > > antithesis, which I find as useful as defining "mammal" to include > > those that are "not mammals". > > It's not that I find it amusing. I was just clarifying my position, > that when I agree with the notion of "cause and effect between > material agents", that isn't to rule out what you call the > "immaterial". > > > > > > > > and show a total unfamiliarity > > > > > with history, science, politics, psychology, economics, or any > > > > > systematic body of human knowledge that might offer any counter to the > > > > > mere spoken word of their priest or other religious figures, or which > > > > > may put a different slant on their beliefs. > > > > > In other words, they are ignorant, uneducated, and cowing to > > > > authority. > > > > Generally they are ignorant and uneducated, but more to the point they > > > accept something as true *simply* because authority says it is true, > > > and same is true for the authority in turn. > > > > > > Indeed, for me, I also take the view that it will often be futile to > > > > > attack ideology using mere logic. Most people hold an ideology because > > > > > in some way or another because it has a concrete function for them, > > > > > ...such as temporally ordered causality between strictly material > > > > agents... > > > > Yes. I said at the outset of my previous post that there is an > > > ideological (although in this context, for clarity, I prefer to say an > > > "axiomatic"-) component to my beliefs - which defines the sort of > > > explanations I'm willing to accept, what sort of evidence I'm willing > > > to accept, etc. > > > > And before you claim that science, or scientists, don't have ideology, > > > I refer you back to what I said many months ago, that an ignorance of > > > ideology, or a lack of concern with it, is not the same as an absence > > > of ideology. > > > There's a vast difference between a set of axioms about how nature > > MUST work, and a set of axioms about an adopted procedure to > > investigate how nature does in fact work. The latter affords you a lot > > more flexibility for proper discovery. > > I don't see how the two can be distinguished. The investigation > procedure is inextricably linked with a hypothesis about how nature > works. A hypothesis that included God's will, for example, would not > include a requirement of reproducibility - because of course there is > no reason a priori why God would respond in the same way each time. > And by the same token, the requirement of reproducibility naturally > stems from a hypothesis that the natural world is controlled in a > mechanical fashion, where the same input will necessarily be expected > to produce the same output. > > As I say Paul, I think you'd do better to concentrate on actually > honing your ability to explain the theory itself, rather than trying > to tenderise people into a state of unquestioning acceptance of what > is about to come (either on the question of physics, or on the > philosophy of science). You overestimate the degree to which I won't > respond to evidence and coherent explanations, but you far > underestimate my resistence to the word of authority and the degree to > which I'm turned off by a pompous prelude about how much the universe > differs from my preconceptions or how amazing or mysterious the > universe is. It evokes the image in my mind of a magician's act, where > there is a sense that the person you're talking to is more interested > in ceremony and inducing confusion, and pulling off a deception > convincingly, as opposed to just explaining in an impartial > straightforward manner. > > And I probably can't deny that some of this is due to fundamental > personality and political differences between us. And what I will say > is that it's quite possible that you've found, in your experience as a > teacher, no doubt teaching young students who know nothing and have > very little between the ears, that the magician's act is actually > useful for provoking interest in the subject amongst those who > otherwise have very little inherent interest. But for me, I really > dislike that approach - I have a fundamental interest in knowledge > generally already, and always have, and I would have no reason to be > here other than sheer personal interest. The difficulty is that you don't have much interest in the physics as explained to you either, if it does not conform to your chosen axioms. In other words, you want not only the physical explanation, but one that you will accept as intuitively consistent with your preconceptions. This is not likely to come to resolution. You attribute your position as coming from a refusal to bow to authority, when it instead gives the impression of lack of imagination on your part. No one expects you to bow to authority. However, you might ask yourself whether you are willing to question your own assumptions in the process of learning about an explanation that perhaps runs counter to them. This is a *choice* on your part, one that would be driven by intellectual curiosity. I've noted that when experimental data are pointed to, you indicate your profound *faith* that there surely is an explanation available that would not cause you to question your own assumptions and that would be compatible with those observations. This *faith* allows you to remain unconvinced of the explanation that is provided. You surely see that this combination of fastly held preconceptions, plus a faith that there is surely somewhere and someday a saving model that adheres to them, will *guarantee* that you remain unconvinced of the explanatory success of the prevailing model. If being convinced is your objective, then you have set yourself up for failure. If you expect others to convince you in the face of and despite that combination, you will find that no one will presume to be able to do that for you. One does not convince a creationist that he is wrong, and one does not teach a Christmas ham.
From: Ste on 12 Apr 2010 14:15
On 12 Apr, 18:25, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > On 12 abr, 12:12, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > On 12 Apr, 16:41, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > wrote: > > > > > and the speed of propagation of signal v is something that is > > > > determined in separate measurements. > > > > But the speed of signal propagation may itself be dependent on the > > > relative velocity (through some unknown dynamic in the electromagnetic > > > interaction). Prima facie, it may be difficult to extricate that > > > variable from other confounding variables. > > > > _________________________________________ > > > It has been explained to you about 1,327 times that the speed of light is > > > independent of the speed of the sender; this is a fundamental postulate of > > > SR, is predicted by Maxwell's equations, and is massively proved > > > experimentally. Are you (a) so stupid that you haven't understood this yet, > > > or (b) saying SR is wrong ? > > > No, I'm saying that SR may well be quantifying this variable, but by > > attributing it to a relativity of simultaneity rather than a variance > > in the speed of propagation. But as I say, I haven't quite got to > > grips with SR yet or how simultaneity changes for the clocks in my > > example, so let's concentrate on that first before going off on > > tangents discussing ideas that are purely speculative and which are > > not based on a complete understanding of SR. > > This response is a textbook example of a troll behavior... That old chestnut agan. |