Preferred Frame Theory indistinguishable from SR
in [Relativity]
|
From: mpc755 on 21 Jul 2010 22:23 In article <9998d10b-df75-4cb7-89a9- 0ec331e8ff6a(a)d37g2000yqm.googlegroups.com>, spamspamspam3(a)netzero.com says... > > On Jul 17, 2:15 am, colp <c...(a)solder.ath.cx> wrote: > > > ... Hafele and Keating had to base > > their SR calculations on a preferred frame of reference. If they had > > used a point on the Earth or either plane then SR would not have > > returned the correct result. > > Because in SR we base our calculations on inertial frames of > reference. In that sense, these are preferred frames. In fact, there > are virtually always preferred frames, even in GR, which claims to > treat all frames as brothers, because there are frames in which the > symmetry of the problem results in simplifications. What's your beef? > Who told you SR had no preferred reference frames? There may be confusion between a preferred reference frame and the absolute frame of reference. The absolute frame of reference is the state of the matter and the state of the dark matter and the state of the dark matter is determined by its connections with the matter which is the dark matter's state of displacement.
From: Inertial on 21 Jul 2010 22:28 "Edward Green" wrote in message news:9998d10b-df75-4cb7-89a9-0ec331e8ff6a(a)d37g2000yqm.googlegroups.com... > >On Jul 17, 2:15 am, colp <c...(a)solder.ath.cx> wrote: > >> ... Hafele and Keating had to base >> their SR calculations on a preferred frame of reference. If they had >> used a point on the Earth or either plane then SR would not have >> returned the correct result. > >Because in SR we base our calculations on inertial frames of >reference. In that sense, these are preferred frames. In fact, there >are virtually always preferred frames, even in GR, which claims to >treat all frames as brothers, because there are frames in which the >symmetry of the problem results in simplifications. What's your beef? >Who told you SR had no preferred reference frames? There is always, for a given problem, some frame or other that one would prefer to calculate wrt (ie the one that is simplest). That doesn't make it a 'preferred frame' in the sense that is used in physics. It s just a sensible choice.
From: Paul Stowe on 21 Jul 2010 22:32 On Jul 21, 6:40 am, PD <thedraperfam...(a)gmail.com> wrote: > On Jul 20, 7:21 pm, Paul Stowe <theaether...(a)gmail.com> wrote: {Snip...} > > > > You are contracting Paul, who said: "Just look at the aspects of > > > > kinetic theory which underpins ALL! fluid theory. There is no concept > > > > of absolutes there." > > > > Read what I just said. The center of mass of the fluid is in no way an > > > absolute frame. > > > Where is the 'center of mass' for the pacific ocean??? > > This is relatively straightforward to calculate. Why would you think > it's difficult? > In general R_cms = int[R*rho*dv]/int[rho*dv], where R_cms and R are > vectors, R is the location of a volume element dv weighted by mass > density rho (rho(R)). > The momentum of any of the elements doesn't enter into it. Can you see > why? > > > I think what > > you really wanted to say is the frame where the local sum of the > > population vector momenta is zero. > > I think that's equivalent. > > > But, note what I said kinetic > > theory 'which underpins' fluid mechanics. At the scales small enough > > where kinetic theory is necessary... But, either way, there is no > > physical preference for any imagined coordinate system, aka, reference > > frame. > > That's not quite right. There's the presumption that (1/2)m(v_rms)_x^2 > = 1/2)m(v_rms)_y^2 = 1/2)m(v_rms)_z^2. This won't be true where there > is a general drift from left to right of the molecules. Then Grad V != 0... With Grad V you have a non-inertial situation, but even then, one can 'localized' their volume of interest to a small enough region such that the Gradient asymptotically vanishes. Paul Stowe > > > > > Paul Stowe- Hide quoted text - > > > - Show quoted text -
From: mpc755 on 21 Jul 2010 22:32 In article <4c47acda$0$11120$c3e8da3(a)news.astraweb.com>, relatively(a)rest.com says... > > "Edward Green" wrote in message > news:9998d10b-df75-4cb7-89a9-0ec331e8ff6a(a)d37g2000yqm.googlegroups.com... > > > >On Jul 17, 2:15 am, colp <c...(a)solder.ath.cx> wrote: > > > >> ... Hafele and Keating had to base > >> their SR calculations on a preferred frame of reference. If they had > >> used a point on the Earth or either plane then SR would not have > >> returned the correct result. > > > >Because in SR we base our calculations on inertial frames of > >reference. In that sense, these are preferred frames. In fact, there > >are virtually always preferred frames, even in GR, which claims to > >treat all frames as brothers, because there are frames in which the > >symmetry of the problem results in simplifications. What's your beef? > >Who told you SR had no preferred reference frames? > > There is always, for a given problem, some frame or other that one would > prefer to calculate wrt (ie the one that is simplest). That doesn't make it > a 'preferred frame' in the sense that is used in physics. It s just a > sensible choice. It does not reflect nature, it reflects mathematics. In the physics of nature, the absolute frame of reference is the state of the matter and the state of the dark matter and the state of the dark matter is determined by its connections with the matter and the state of the dark matter is its state of displacement.
From: PD on 21 Jul 2010 23:33
On Jul 21, 9:16 pm, Edward Green <spamspamsp...(a)netzero.com> wrote: > On Jul 17, 2:15 am, colp <c...(a)solder.ath.cx> wrote: > > > ... Hafele and Keating had to base > > their SR calculations on a preferred frame of reference. If they had > > used a point on the Earth or either plane then SR would not have > > returned the correct result. > > Because in SR we base our calculations on inertial frames of > reference. In that sense, these are preferred frames. In fact, there > are virtually always preferred frames, even in GR, which claims to > treat all frames as brothers, because there are frames in which the > symmetry of the problem results in simplifications. What's your beef? > Who told you SR had no preferred reference frames? Let's make a small but important distinction. "Preferred frame" does not mean "the frame in which it is easiest to make calculations". A similar situation arises with potential energy, where the choice of (x,y,z) to set U(x,y,z)=0 is physically arbitrary, which is an important statement physically. There are of course choices for such zero-point-setting which do make calculations easier, but physically there is no difference. |