De Sitter's experiment and the relative motion of photons with respect to the surface of the star
in [Relativity]
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From: Henry Wilson DSc on 1 Feb 2010 22:02 On Mon, 1 Feb 2010 17:00:50 -0800 (PST), PD <thedraperfamily(a)gmail.com> wrote: >On Feb 1, 5:59�pm, train <gehan.ameresek...(a)gmail.com> wrote: >> On Feb 2, 12:32�am, Tom Roberts <tjrob...(a)sbcglobal.net> wrote:> train wrote: >> > > if we all adopted LET would we be able to explain all >> >> .... >> >> >> >> >> >> > >> Because the closing speed has NOTHING WHATSOEVER to do with the physical process >> > >> of emitting photons (light). >> >> > > Scientists make observations and perform calculations. Arent' both are >> > > equally valid? >> >> > For what purpose? One can measure and compute just about anything. But if one >> > wants to model the emission process at the surface of a star, the closing speed >> > measured in the frame of some distant observer is UTTERLY IRRELEVANT. >> >> > > If the calculated emission speed is different for different places in >> > > the orbit of the star, what can this be attributed to then? >> >> > To the fact that the star is moving IN AN ORBIT relative to the frame used to >> > compute the closing speed. Remember that closing speeds are not physically >> > relevant to any process or phenomena, and are merely bookkeeping in the frame >> > used to compute them. The fact that they behave in what you think is a curious >> > manner is just due to the way the bookkeeping works out. >> >> The observation of the star or binary stars is an observation of a >> phenomenon, so is the observation of the emission of light from the >> star. Measurements and calculations are applied to a process being >> observed. >> >> If the constancy of the speed of light is assumed, and assumed to be >> supported by the facts, >> then what reason can be given for the physical process by which >> photons are emitted from the star >> at different velocities depending on the direction of the star? > >They aren't. You are assuming that different closing velocities >corresponds to different speeds of emission. Nothing could be further >from the truth. That is the point of several of the responses here, >including Eric's, Tom's and mine. > >> >> The answer may be 'it appears to be so' or 'that's just the way it >> is'. However is not the principle of equivalence violated since a >> certain phenomenon, a 'physical experiment' is showing different >> results based the direction the relative motion of the star to a >> distant object? > >This is not what the principle of equivalence says. The principle of >equivalence makes NO claim that the "results" will be the same in >different inertial frames. This is KNOWN not to be true from the days >of Galileo. A ball falling from the top of the mast on a ship takes a >straight line path in the frame of a ship, but a parabolic path in the >frame of the shore -- two different "results" regarding the same >events as seen in two different frames. What the principle of >equivalence says is that the laws of physics are the same in all >inertial frames -- and a parabolic path and a straight line path are >both described by the very same laws of physics. ....but you still can't provide a logical physical reason as to why a light pulse should reflect at the same speed from two relatively moving mirrors. Henry Wilson... ........provider of free physics lessons
From: eric gisse on 1 Feb 2010 23:18 ...@..(Henry Wilson DSc) wrote: [...] > > ...but you still can't provide a logical physical reason as to why a light > pulse should reflect at the same speed from two relatively moving mirrors. a) Maxwell's equations b) Lorentz invariance c) BECAUSE IT DOES. OBSERVATIONALLY. SUCK IT UP. Pick whichever one you like. > > Henry Wilson... > > .......provider of free physics lessons
From: Henry Wilson DSc on 1 Feb 2010 23:17 On Mon, 1 Feb 2010 19:23:37 -0800 (PST), artful <artful_me(a)hotmail.com> wrote: >On Feb 2, 2:02�pm, ..@..(Henry Wilson DSc) wrote: >> On Mon, 1 Feb 2010 17:00:50 -0800 (PST), PD <thedraperfam...(a)gmail.com> wrote: >> >On Feb 1, 5:59�pm, train <gehan.ameresek...(a)gmail.com> wrote: >> >This is not what the principle of equivalence says. The principle of >> >equivalence makes NO claim that the "results" will be the same in >> >different inertial frames. This is KNOWN not to be true from the days >> >of Galileo. A ball falling from the top of the mast on a ship takes a >> >straight line path in the frame of a ship, but a parabolic path in the >> >frame of the shore -- two different "results" regarding the same >> >events as seen in two different frames. What the principle of >> >equivalence says is that the laws of physics are the same in all >> >inertial frames -- and a parabolic path and a straight line path are >> >both described by the very same laws of physics. >> ...but you still can't provide a logical physical reason as to why a light >> pulse should reflect at the same speed from two relatively moving mirrors. >> >> Henry Wilson... >> >> .......provider of free physics lessons > >The incident speed wrt the mirror is the same as the reflected speed >wrt the mirror. That is how mirrors work. Do you have a problem with >that? I don't...but Einstein obviously did. S-----p->c(wrt source)--------------|M1 |M2 v<- Let the pulse strike the two mirrors when they are adjacent. It closes on M1 at c and departs at c. It closes on M2 at c+v and departs at c-v. Strange, eh? I wonder how many fairies can dance on the surface of a mirror. >Then use velocity composition to work out how that speed will >be in another relatively moving inertial frame. Use vector addition / >subtraction to work out closing/separation speeds Hahahahhaaha! What kind of answer is this? Einstein's velocity composition equation is just another form of his P2. Look, I'll show you... Let w (the light speed in a frame moving at v) always be = c by postulate. w = c = c(c+v)/(c+v) = (c+v)/(1+v/c) = (c+v)/(1+vc/c^2) ....can I have my Nobel now please...for being expert at sniffing out circular logic? Henry Wilson... ........provider of free physics lessons
From: eric gisse on 2 Feb 2010 01:28 ...@..(Henry Wilson DSc) wrote: [...] > > Let the pulse strike the two mirrors when they are adjacent. > It closes on M1 at c and departs at c. > It closes on M2 at c+v and departs at c-v. > Strange, eh? Yeah, strange that you still obsess over 'closing speeds' as if they were relevant. > > I wonder how many fairies can dance on the surface of a mirror. > >>Then use velocity composition to work out how that speed will >>be in another relatively moving inertial frame. Use vector addition / >>subtraction to work out closing/separation speeds > > Hahahahhaaha! What kind of answer is this? The correct one. > > Einstein's velocity composition equation is just another form of his P2. > Look, I'll show you... Well, yes, predictions of postulates tend to contain the original postulates in some form. Not quite sure what you expected. > > Let w (the light speed in a frame moving at v) always be = c by postulate. > > w = c = c(c+v)/(c+v) = (c+v)/(1+v/c) = (c+v)/(1+vc/c^2) > > ...can I have my Nobel now please...for being expert at sniffing out > circular logic? Apparently you think it is silly for a theory to be self consistent? > > > > Henry Wilson... > > .......provider of free physics lessons
From: Henry Wilson DSc on 2 Feb 2010 04:32
On Mon, 1 Feb 2010 21:20:20 -0800 (PST), artful <artful_me(a)hotmail.com> wrote: >On Feb 2, 3:17�pm, ..@..(Henry Wilson DSc) wrote: >> On Mon, 1 Feb 2010 19:23:37 -0800 (PST), artful <artful...(a)hotmail.com> wrote: >> >The incident speed wrt the mirror is the same as the reflected speed >> >wrt the mirror. That is how mirrors work. �Do you have a problem with >> >that? � >> >> I don't...but Einstein obviously did. > >No .. he had no problem at all with that. > >> S-----p->c(wrt source)--------------|M1 >> � � � � � � � � � � � � � � � � � � � � � � � � � � � |M2 v<- >> >> Let the pulse strike the two mirrors when they are adjacent. >> It closes on M1 at c and departs at c. >> It closes on M2 at c+v and departs at c-v. >> Strange, eh? > >Not at all. Closing speed is NOT the speed the light was incident on >the mirror. You need the speed in the FRAME OF THE MIRROR Not according to Einstein. He needs the speed in the frame of the soruce. >> I wonder how many fairies can dance on the surface of a mirror. > >Do you believe in fairies. Now THAT is strange I don't. Relativists do. >> >Then use velocity composition to work out how that speed will >> >be in another relatively moving inertial frame. Use vector addition / >> >subtraction to work out closing/separation speeds >> >> Hahahahhaaha! What kind of answer is this? > >A correct one > >> Einstein's velocity composition equation is just another form of his P2. > >Nope .. but it does clearly follow from it > >> Look, I'll show you... > >This should be amusing > >> Let w (the light speed in a frame moving at v) always be = c by postulate. > >Of course it is .. and velocity composition gives you that as well. >Is that nice. > >> w = c = c(c+v)/(c+v) = (c+v)/(1+v/c) = (c+v)/(1+vc/c^2) > >Yeup .. nothing wrong with that > >> ...can I have my Nobel now please...for being expert at sniffing out circular >> logic? > >Nothing circular there .. and no logic on your part. Perhaps you can >get a prize for biggest failure? The velocity addition equation when applied to ligth is just a bit of trick maths restating the second postulate. It might impress little boys but it doesn't prove anything. Henry Wilson... ........provider of free physics lessons |