CMBR's motion wrt the Earth
in [Relativity]
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From: mluttgens on 18 Sep 2009 10:03 On 13 sep, 15:55, Sam Wormley <sworml...(a)mchsi.com> wrote: > mluttgens wrote: > > > Special relativity theory should be called the Theory of Mutual > > Time Dilation. Clearly, mutual time dilation is nonsensical. > > SRists found a solution for the twin paradox, explaining why "both > > twins cannot be younger than each other", but consider normal > > that two clocks moving relative to each other, for instance on > > a road, show the same time dilation. Contradiction doesn't bother > > them. They don't even try to find a general solution for > > the nonsense, and modify SR accordingly. > > > Marcel Luttgens > > Marcel, you should take some time to learn what special > relativity really says. One cannot have more than one > perspective simultaneously. There has yet to be an observation > that contradicts a prediction of special relativity. Let's consider two objects A and B in uniform translatory motion. According to SR, if A moves at v toward B, reciprocally, B moves at -v toward A. SR obviously doesn't take into consideration the velocities vA and vB of the objects relative to the CMBR (sometimes rightly called the rest frame of the universe). Let v be the velocity of A wrt B. From the dipole anisotropy it observes, B determines that its velocity relative to the CMBR is vB, whose direction is the same as v. According to the CMBR observer (using c=1), vA = (v-vB)/(1-vB*v) tB = tCMBR * sqrt(1-vB^2) tA = tCMBR * sqrt(1-((v-vB)/(1-vB*v))^2) = tCMBR * sqrt1-vB^2)*sqrt(1-v^2)/(1-vB*v) Hence, tA = tB * sqrt(1-v^2) / (1-vB*v). Clearly, the SR formula tA = tB * sqrt(1-v^2) is correct only when B is at rest in the CMBR (vB = 0). But even in this case, SRists falsely claim that B moves at -v relative to A, and thus, that tB = tA * sqrt(1-v^2). Simply by looking at the CMBR, B knows that its velocity vB is a physical fact, which is of course independent of the hypothesis that motion is relative and that the time dilation effect is correlatively reciprocal. Marcel Luttgens
From: PD on 18 Sep 2009 10:26 On Sep 18, 9:03 am, mluttgens <mluttg...(a)orange.fr> wrote: > On 13 sep, 15:55, Sam Wormley <sworml...(a)mchsi.com> wrote: > > > > > mluttgens wrote: > > > > Special relativity theory should be called the Theory of Mutual > > > Time Dilation. Clearly, mutual time dilation is nonsensical. > > > SRists found a solution for the twin paradox, explaining why "both > > > twins cannot be younger than each other", but consider normal > > > that two clocks moving relative to each other, for instance on > > > a road, show the same time dilation. Contradiction doesn't bother > > > them. They don't even try to find a general solution for > > > the nonsense, and modify SR accordingly. > > > > Marcel Luttgens > > > Marcel, you should take some time to learn what special > > relativity really says. One cannot have more than one > > perspective simultaneously. There has yet to be an observation > > that contradicts a prediction of special relativity. > > Let's consider two objects A and B in uniform > translatory motion. > > According to SR, if A moves at v toward B, > reciprocally, B moves at -v toward A. Not just according to SR. According to Galilean/Newtonian physics, too. And in fact, in Aristotelean physics. > SR obviously doesn't take into consideration > the velocities vA and vB of the objects relative > to the CMBR (sometimes rightly called the rest > frame of the universe). The motion with respect to a third benchmark is not necessary at all. This is the statement that I made to you earlier in this same thread, and which you seem to have almost immediately forgotten. Relative motion is a statement about A relative to B or B relative to A, and there is no C required. > > Let v be the velocity of A wrt B. > From the dipole anisotropy it observes, B > determines that its velocity relative to the > CMBR is vB, whose direction is the same as v. > > According to the CMBR observer (using c=1), > vA = (v-vB)/(1-vB*v) > tB = tCMBR * sqrt(1-vB^2) > tA = tCMBR * sqrt(1-((v-vB)/(1-vB*v))^2) > = tCMBR * sqrt1-vB^2)*sqrt(1-v^2)/(1-vB*v) > Hence, tA = tB * sqrt(1-v^2) / (1-vB*v). > > Clearly, the SR formula tA = tB * sqrt(1-v^2) > is correct only when B is at rest in the CMBR > (vB = 0). > But even in this case, SRists falsely claim > that B moves at -v relative to A, and thus, that > tB = tA * sqrt(1-v^2). Simply by looking at the > CMBR, B knows that its velocity vB is a physical > fact, which is of course independent of the hypothesis > that motion is relative and that the time dilation > effect is correlatively reciprocal. > > Marcel Luttgens
From: Sam Wormley on 18 Sep 2009 10:53 mluttgens wrote: > > Let's consider two objects A and B in uniform > translatory motion. > > According to SR, if A moves at v toward B, > reciprocally, B moves at -v toward A. > SR obviously doesn't take into consideration > the velocities vA and vB of the objects relative > to the CMBR (sometimes rightly called the rest > frame of the universe). I was going to reply similar to PD, for you are attributing concepts to SR that predate SR by millennia. Time dilation from A's perspective: t_B' = γ (t_B - x v/c^2) Time dilation from B's perspective: t_A' = γ (t_A - x v/c^2) where v is the relative velocity between A and B and γ = 1/â(1-v^2/c^2) .
From: Dirk Van de moortel on 18 Sep 2009 12:08 Sam Wormley <swormley1(a)mchsi.com> wrote in message H9Nsm.55993$la3.20752(a)attbi_s22 > mluttgens wrote: > >> >> Let's consider two objects A and B in uniform >> translatory motion. >> >> According to SR, if A moves at v toward B, >> reciprocally, B moves at -v toward A. >> SR obviously doesn't take into consideration >> the velocities vA and vB of the objects relative >> to the CMBR (sometimes rightly called the rest >> frame of the universe). > > I was going to reply similar to PD, for you are > attributing concepts to SR that predate SR by > millennia. > > Time dilation from A's perspective: > > t_B' = γ (t_B - x v/c^2) That's only time dilation for x = 0 and x measured in B's frame. > > Time dilation from B's perspective: > > t_A' = γ (t_A - x v/c^2) .... and that's only time dilation for x = 0 and x measured in A's frame. > > where v is the relative velocity between A and B > and γ = 1/√(1-v^2/c^2) . bit confused? Dirk Vdm
From: Sam Wormley on 18 Sep 2009 15:37
Dirk Van de moortel wrote: > Sam Wormley <swormley1(a)mchsi.com> wrote in message > H9Nsm.55993$la3.20752(a)attbi_s22 >> mluttgens wrote: >> >>> >>> Let's consider two objects A and B in uniform >>> translatory motion. >>> >>> According to SR, if A moves at v toward B, >>> reciprocally, B moves at -v toward A. >>> SR obviously doesn't take into consideration >>> the velocities vA and vB of the objects relative >>> to the CMBR (sometimes rightly called the rest >>> frame of the universe). >> >> I was going to reply similar to PD, for you are >> attributing concepts to SR that predate SR by >> millennia. >> >> Time dilation from A's perspective: >> >> t_B' = γ (t_B - x v/c^2) > > That's only time dilation for x = 0 and x measured > in B's frame. > >> >> Time dilation from B's perspective: >> >> t_A' = γ (t_A - x v/c^2) > > ... and that's only time dilation for x = 0 and x measured > in A's frame. > >> >> where v is the relative velocity between A and B >> and γ = 1/â(1-v^2/c^2) . > > bit confused? > > Dirk Vdm No, just sloppy and in a hurry. Time dilation from A's perspective: ât_B' = γ ât_B Time dilation from B's perspective: ât_A' = γ ât_A where ât represent a time interval, v is the relative velocity between A and B, and γ = 1/â(1-v^2/c^2) . |