Known physics defeated by simple puzzle?
in [Relativity]
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From: PD on 12 Apr 2010 11:21 On Apr 12, 9:52 am, "Sue..." <suzysewns...(a)yahoo.com.au> wrote: > On Apr 12, 10:30 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 12, 9:10 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 12 Apr, 13:25, "Inertial" <relativ...(a)rest.com> wrote: > > > > > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > > >news:4164eef8-bc24-4e52-9071-ae455ad3f77f(a)w42g2000yqm.googlegroups.com... > > > > > > On 12 Apr, 12:07, "Inertial" <relativ...(a)rest.com> wrote: > > > > >> "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > > > >>news:0faebd8d-d6fd-4475-8996-f96717fbb594(a)11g2000yqr.googlegroups..com... > > > > > >> > On 12 Apr, 11:45, "Inertial" <relativ...(a)rest.com> wrote: > > > > >> >> "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > > > >> >> > Now, to what degree is the distant clock appearing retarded (or > > > > >> >> > advanced), and how (i.e. to what degree) is that retardation or > > > > >> >> > advance related to: > > > > >> >> > a) distance; and > > > > >> >> > b) velocity? > > > > > >> >> See the lorentz transforms > > > > > >> > I was hoping you'd spell it out Inertial. > > > > > >> But you refuse to read mathematic > > > > > > I don't refuse to, but bear in mind my current level of competence. > > > > > Also, bear in mind that this particular, narrow question *is* one that > > > > > lends itself to a mathematical quantification, since I am asking the > > > > > question "what", not "why". > > > > > >> > You'd think with the > > > > >> > hundreds of thousands of words we've already put down on this issue, > > > > >> > you wouldn't be averse to a little clarity at this stage of the game. > > > > > >> I will do so, if you actually want to see the math. In which case, the > > > > >> Lorentz transforms give the answers. I can explain them in words, if you > > > > >> can't work it out > > > > > > Ok. > > > > > >> >> >> > And they both argue that it is the *other* who is lagging? > > > > > >> >> >> It is the *other* clock in your example is ahead .. not lagging > > > > > >> >> > At what point? > > > > > >> >> When they start moving toward each other > > > > > >> > OK. Does the distant clock always advance, even if they are moving > > > > >> > *away* from each other? > > > > > >> It always ticks in a forward direction .. time doesn't go backward. So > > > > >> it > > > > >> is always advancing. > > > > > > Yes, but obviously I mean the relative simultaneity of the "ticks" of > > > > > the clock. In other words, does the local clock read, say, 00:20 > > > > > before or after the distant clock (in other words, is the distant > > > > > clock ahead or advanced, or is it behind or retarded). > > > > > >> 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. 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, > > and the speed of propagation of signal v is something that is > > determined in separate measurements. 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. > > That is NOT the propagation of the > relativity of simultaneity-exercise. Yes, it is, as described below in your own quote. Are you incapable of understanding what you read? > > <<There is only one demand to be made of the > definition of simultaneity, namely, that in > every real case it must supply us with an > empirical decision as to whether or not the > conception that has to be defined is fulfilled. > That my definition satisfies this demand is > indisputable. That light requires the same time > to traverse the path A > M as for the path B > M > is in reality neither a supposition nor a hypothesis > about the physical nature of light, but a stipulation > which I can make of my own freewill in order > to arrive at a definition of simultaneity.>>http://www.bartleby.com/173/8.html > > We are now on PD's second defence > about the crack in the ming vass. > > http://www.quackwatch.org/01QuackeryRelatedTopics/pseudo.html > > Sue... > > > > > > Although obviously I'll bear in mind your comments. > > > > > We don't need to use just what information comes via EM to a single observer > > > > location. We consider things happening simultaneously anywhere throughout > > > > the frame (ie as though the information was sent instantaneously). That is > > > > WHY you supposedly different definition of simultaneity is just the same as > > > > what SR uses anyway .. and ends up being frame dependent. > > > > Indeed. Well, I'll run with it for now. > >
From: PD on 12 Apr 2010 11:26 On Apr 12, 9:53 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 12 Apr, 15:05, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 12, 3:15 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 12 Apr, 05:12, "Inertial" <relativ...(a)rest.com> wrote: > > > > > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > > > >> > 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. > > > > > Then that is your problem. It doesn't mean the physics is wrong ... just you > > > > are unwilling to accept that it is right. > > > > I didn't say physics was wrong. I was alluding more to Paul's notions > > > about premonition and cause, or about the universe not being governed > > > by cause and effect, which I think is nonsense (and so would many > > > physicists). > > > I didn't say the universe is not governed by cause and effect at all. > > What I've said is that *temporally ordered* cause and effect is not > > necessarily the rule -- and this is a concept that seems to elude you, > > since you believe that the *meaning* of cause and effect implies > > temporal ordering, which is simply not the case scientifically. What > > Indeed. Even the logic of backwards causation is lunacy, and I can't > believe for a second that there is actually any experimental evidence > for it. I'm sorry, Ste, but if you come predisposed to disbelieve experimental evidence in science, because it conflicts with your preconceptions, then you have automatically removed yourself from participation in science. > > > I've also said is that strict determinism, in the sense that > > completely identical prepared states will always evolve identically, > > is not a fast rule of nature though there are plenty of approximate > > examples of that. > > But again, this is mere opinion, and certainly not a unanimous one > amongst the physics community (now or in the past). It is a consensus of a vastly dominant majority. There are some physicists who also believe in cold fusion, despite the consensus of a vastly dominant majority. There are some physicists who also believe in perpetual motion machines, despite then consensus of a vastly dominant majority. As far as I know, there is no unanimity on *any* assertion made in physics, nor does there need to be. This does not render the assertion "mere opinion".
From: Peter Webb on 12 Apr 2010 11:41 > 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 ? > 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? _________________________________________ It has been explained to you about 1,327 times that the speed of light is independent of the speed of the receiver; 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 ?
From: Sue... on 12 Apr 2010 11:50 On Apr 12, 11:14 am, Ste <ste_ro...(a)hotmail.com> wrote: [...] > > But is it independent of the speed of the receiver? << where epsilon_0 and mu_0 are physical constants which can be evaluated by performing two simple experiments which involve measuring the force of attraction between two fixed charges and two fixed parallel current carrying wires. According to the relativity principle, these experiments must yield the same values for epsilon_0 and mu_0 in all inertial frames. Thus, the speed of light must be the same in all inertial frames. >> http://farside.ph.utexas.edu/teaching/em/lectures/node108.html http://en.wikipedia.org/wiki/Vacuum_permeability http://en.wikipedia.org/wiki/Vacuum_permittivity "What is the Interstellar Medium?" http://espg.sr.unh.edu/ism/what1.html Sue...
From: Ste on 12 Apr 2010 12:12
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. |