CMBR's motion wrt the Earth
in [Relativity]
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From: Albertito on 8 Sep 2009 09:20 On Sep 8, 1:55 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Sep 8, 7:48 am, Albertito <albertito1...(a)gmail.com> wrote: > > > > > On Sep 8, 1:31 pm, "Inertial" <relativ...(a)rest.com> wrote: > > > > "Albertito" <albertito1...(a)gmail.com> wrote in message > > > >news:e18d05b1-bd58-4d12-8f0a-9b68f49997e5(a)o41g2000yqb.googlegroups.com... > > > > > On Sep 8, 12:07 pm, mluttgens <mluttg...(a)orange.fr> wrote: > > > >> On 7 sep, 20:15, PD <thedraperfam...(a)gmail.com> wrote: > > > > >> > On Sep 6, 7:53 am, mluttgens <mluttg...(a)orange.fr> wrote: > > > > >> > > CMBR's motion wrt the Earth > > > >> > > ------------------------------------------ > > > > >> > > In cosmology, cosmic microwave background (CMB) radiation > > > >> > > (also CMBR, CBR, MBR, and relic radiation) is a form of > > > >> > > electromagnetic radiation filling the universe. > > > >> > > (fromhttp://en.wikipedia.org/wiki/CMBR) > > > > >> > > By measuring the amount of the dipole anisotropy (the bluest > > > >> > > part of the sky is .0033 K hotter than average), we can determine > > > >> > > the magnitude of the earth's motion with respect to the CMB: > > > >> > > the earth is moving at a speed of 370 km/s in the direction > > > >> > > of the constellation Virgo. > > > >> > > (fromhttp://www.phy.duke.edu/~kolena/cmb.htm) > > > > >> > > It (the CMBR) does move with respect to an object. > > > >> > > (from PD <thedraperfam...(a)gmail.com>, Sep 5, 2009) > > > > >> > > Clearly, the Earth moves wrt the CMBR. According to SR, > > > >> > > reciprocally, the CMBR moves wrt the Earth. > > > >> > > Can somebody explain how, physically, an electromagnetic > > > >> > > radiation filling the universe can move relative to the Earth? > > > > >> > > Marcel Luttgens > > > > >> > I think you are confused about what relative motion means, Marcel. You > > > >> > have in your head that motion is an absolute statement, as in either > > > >> > something is in motion or it's not. This is not the case. > > > > >> > If you have car and a stop sign and a fire hydrant, the car is in > > > >> > motion relative to the stop sign, and the stop sign is in motion > > > >> > relative to the car, and the fire hydrant is not in motion relative to > > > >> > the stop sign, and the stop sign is not in relative to the fire > > > >> > hydrant, and the fire hydrant is in motion relative to the car, and > > > >> > the car is in motion relative to the fire hydrant. > > > > >> > I think you have it in your head that if you have two objects A and B > > > >> > and they are in relative motion, then this means that one of them is > > > >> > in motion and the other is not. As in, A is in motion relative to B, > > > >> > but B is not in motion relative to A. > > > > >> No, what I have in my head is that if A is in motion relative > > > >> to the CMBR, it is impossible to physically demonstrate that > > > >> the CMBR moves wrt A. > > > > >> Marcel Luttgens > > > > >> > When you say that you don't believe the CMBR is in motion relative to > > > >> > the earth, I believe you think this because you somehow believe the > > > >> > CMBR is fixed and stationary in some absolute sense and so can't be in > > > >> > any kind of motion, relative or not. I don't know where you got this > > > >> > idea. > > > > >> > PD > > > > > You are right Marcel. CMBR conforms an absolute frame > > > > of reference in the sense that the sources that emitted > > > > those CMBR photons were so distant from us, that their > > > > respective angular positions have not changed a bit since > > > > the emission events to the absoption ones. > > > > It is a frame, but nothing absolute about it. The physics of that frame is > > > the same as any other. It is a significant frame (especially to > > > astronomers) > > > > > I can rember a wonderful thread started by Henri Wilson > > > > in this very forum called "Why are the 'Fixed Stars' so FIXED?" > > > >http://groups.google.com/group/sci.physics.relativity/msg/82337144cdc... > > > > Oh gawd, not Henry. He has some weird ideas, and an amazing lack of > > > understanding about physics, and ability to post untruths with apparently no > > > remorse. > > > So, you do not know what an absolute frame of reference is? > > I'll give you some notions about it. Trace an angular position > > in your nightsky. Now, try to guess some distant source of > > light in that very angular position that emitted a photon > > towards you. The more distant the source was, the better > > for your fixed frame. So, infinite distant sources define > > an absolute frame of reference. > > I take it this is YOUR private definition of "absolute frame". What > other private definitions for other physics terms do you have? > > > Finite but highly distant > > sources define a quasi-absolute frame of reference. > > What has the CMBR of special? The laws of physiscs in > > a lab at rest in that frame would look simpler. Example, > > an atomic clock would tick at the fastest rate if it is at > > rest in that CMBR frame (dipole=0) In this case, you should take things as being useful or useless, but private or not private is not a wise choise for understanding the issue. You, being a good Einstein's relativity worshiper, can easily understand that Einstein's ideas were firstly private, and then they become of public domain.
From: PD on 8 Sep 2009 09:35 On Sep 8, 8:20 am, Albertito <albertito1...(a)gmail.com> wrote: > On Sep 8, 1:55 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Sep 8, 7:48 am, Albertito <albertito1...(a)gmail.com> wrote: > > > > On Sep 8, 1:31 pm, "Inertial" <relativ...(a)rest.com> wrote: > > > > > "Albertito" <albertito1...(a)gmail.com> wrote in message > > > > >news:e18d05b1-bd58-4d12-8f0a-9b68f49997e5(a)o41g2000yqb.googlegroups.com... > > > > > > On Sep 8, 12:07 pm, mluttgens <mluttg...(a)orange.fr> wrote: > > > > >> On 7 sep, 20:15, PD <thedraperfam...(a)gmail.com> wrote: > > > > > >> > On Sep 6, 7:53 am, mluttgens <mluttg...(a)orange.fr> wrote: > > > > > >> > > CMBR's motion wrt the Earth > > > > >> > > ------------------------------------------ > > > > > >> > > In cosmology, cosmic microwave background (CMB) radiation > > > > >> > > (also CMBR, CBR, MBR, and relic radiation) is a form of > > > > >> > > electromagnetic radiation filling the universe. > > > > >> > > (fromhttp://en.wikipedia.org/wiki/CMBR) > > > > > >> > > By measuring the amount of the dipole anisotropy (the bluest > > > > >> > > part of the sky is .0033 K hotter than average), we can determine > > > > >> > > the magnitude of the earth's motion with respect to the CMB: > > > > >> > > the earth is moving at a speed of 370 km/s in the direction > > > > >> > > of the constellation Virgo. > > > > >> > > (fromhttp://www.phy.duke.edu/~kolena/cmb.htm) > > > > > >> > > It (the CMBR) does move with respect to an object. > > > > >> > > (from PD <thedraperfam...(a)gmail.com>, Sep 5, 2009) > > > > > >> > > Clearly, the Earth moves wrt the CMBR. According to SR, > > > > >> > > reciprocally, the CMBR moves wrt the Earth. > > > > >> > > Can somebody explain how, physically, an electromagnetic > > > > >> > > radiation filling the universe can move relative to the Earth? > > > > > >> > > Marcel Luttgens > > > > > >> > I think you are confused about what relative motion means, Marcel. You > > > > >> > have in your head that motion is an absolute statement, as in either > > > > >> > something is in motion or it's not. This is not the case. > > > > > >> > If you have car and a stop sign and a fire hydrant, the car is in > > > > >> > motion relative to the stop sign, and the stop sign is in motion > > > > >> > relative to the car, and the fire hydrant is not in motion relative to > > > > >> > the stop sign, and the stop sign is not in relative to the fire > > > > >> > hydrant, and the fire hydrant is in motion relative to the car, and > > > > >> > the car is in motion relative to the fire hydrant. > > > > > >> > I think you have it in your head that if you have two objects A and B > > > > >> > and they are in relative motion, then this means that one of them is > > > > >> > in motion and the other is not. As in, A is in motion relative to B, > > > > >> > but B is not in motion relative to A. > > > > > >> No, what I have in my head is that if A is in motion relative > > > > >> to the CMBR, it is impossible to physically demonstrate that > > > > >> the CMBR moves wrt A. > > > > > >> Marcel Luttgens > > > > > >> > When you say that you don't believe the CMBR is in motion relative to > > > > >> > the earth, I believe you think this because you somehow believe the > > > > >> > CMBR is fixed and stationary in some absolute sense and so can't be in > > > > >> > any kind of motion, relative or not. I don't know where you got this > > > > >> > idea. > > > > > >> > PD > > > > > > You are right Marcel. CMBR conforms an absolute frame > > > > > of reference in the sense that the sources that emitted > > > > > those CMBR photons were so distant from us, that their > > > > > respective angular positions have not changed a bit since > > > > > the emission events to the absoption ones. > > > > > It is a frame, but nothing absolute about it. The physics of that frame is > > > > the same as any other. It is a significant frame (especially to > > > > astronomers) > > > > > > I can rember a wonderful thread started by Henri Wilson > > > > > in this very forum called "Why are the 'Fixed Stars' so FIXED?" > > > > >http://groups.google.com/group/sci.physics.relativity/msg/82337144cdc... > > > > > Oh gawd, not Henry. He has some weird ideas, and an amazing lack of > > > > understanding about physics, and ability to post untruths with apparently no > > > > remorse. > > > > So, you do not know what an absolute frame of reference is? > > > I'll give you some notions about it. Trace an angular position > > > in your nightsky. Now, try to guess some distant source of > > > light in that very angular position that emitted a photon > > > towards you. The more distant the source was, the better > > > for your fixed frame. So, infinite distant sources define > > > an absolute frame of reference. > > > I take it this is YOUR private definition of "absolute frame". What > > other private definitions for other physics terms do you have? > > > > Finite but highly distant > > > sources define a quasi-absolute frame of reference. > > > What has the CMBR of special? The laws of physiscs in > > > a lab at rest in that frame would look simpler. Example, > > > an atomic clock would tick at the fastest rate if it is at > > > rest in that CMBR frame (dipole=0) > > In this case, you should take things as being useful or > useless, but private or not private is not a wise choise > for understanding the issue. You, being a good Einstein's > relativity worshiper, can easily understand that Einstein's > ideas were firstly private, and then they become of public > domain. You'll notice that Einstein didn't have any private definitions of physics terms that were already in use.
From: Ken Quirici on 8 Sep 2009 09:46 On Sep 8, 6:24 am, "Sandcastle" <i...(a)vipilot.com> wrote: > "Koobee Wublee" <koobee.wub...(a)gmail.com> wrote in message > > news:91d6f4d1-739a-4036-9b50-6a9db061edbf(a)37g2000yqm.googlegroups.com... > > > > > > > On Sep 7, 5:48 am, "Sandcastle" <i...(a)vipilot.com> wrote: > >> "Koobee Wublee" wrote: > > >> > If there was a Big Bang, there must be an absolute frame of > >> > reference. <shrug> Thus, yours truly is not surprised that there is > >> > a dipole shift to the CMBR. <shrug> Accepting the Big Bang and > >> > denying the absolute frame of reference is a contradictory concept. > >> > It is utterly absurd. <shrug> > > >> If you think of the Big Bang as starting at a single point in space, your > >> statemente above would be true. But if you think of the big bang as all > >> of > >> space time existing as a singularity, and that singularity is just > >> expanding, then the lack of a frame of reference is no longer absurd. > > > Hmmm... You are assuming the Big Bang started in a singularity based > > on false mathematical models. What if it did not? There would be no > > need for the absurdity in inflation where space can curve and expand > > faster than the speed of light. > > No. I am assuming the Big Bang started in a singularity based on the concept > that space-time is doing the expansion, not something sitting in space-time. > To date there has been no challenge to space-time (with the exception of > violation of Bell's Theorem in experiments based on an erroneous assumption > rather than the theorem). > > If you accept space-time, then there is no such thing as faster than the > speed of light. Time is almost at a standstill as you approach the speed of > light and distances have reduced to zero. For example, if you could ride on > a light beam, you would instantaneously travel the width of the universe. > The photon is created at its source the same instant that it is destroyed at > its destination. But an observer, not near the speed of the light beam would > measure the time in billions of light years. You're saying the universe physically expands from the point of time of the Big Bang from a size of 0 meters to, after billions of light years, to a diameter of billions of light years. In another thread I think I found out why you can't find the center of the expansion - all velocity vectors of distant galaxies (and other objects) point directly away from us because of the addition of velocity vectors relative to the center of the expansion.
From: Inertial on 8 Sep 2009 09:50 "PD" <thedraperfamily(a)gmail.com> wrote in message news:6e60187f-bf53-4a80-b4b7-7244607c74b1(a)l13g2000yqb.googlegroups.com... > On Sep 8, 7:48 am, Albertito <albertito1...(a)gmail.com> wrote: >> On Sep 8, 1:31 pm, "Inertial" <relativ...(a)rest.com> wrote: >> >> >> >> > "Albertito" <albertito1...(a)gmail.com> wrote in message >> >> >news:e18d05b1-bd58-4d12-8f0a-9b68f49997e5(a)o41g2000yqb.googlegroups.com... >> >> > > On Sep 8, 12:07 pm, mluttgens <mluttg...(a)orange.fr> wrote: >> > >> On 7 sep, 20:15, PD <thedraperfam...(a)gmail.com> wrote: >> >> > >> > On Sep 6, 7:53 am, mluttgens <mluttg...(a)orange.fr> wrote: >> >> > >> > > CMBR's motion wrt the Earth >> > >> > > ------------------------------------------ >> >> > >> > > In cosmology, cosmic microwave background (CMB) radiation >> > >> > > (also CMBR, CBR, MBR, and relic radiation) is a form of >> > >> > > electromagnetic radiation filling the universe. >> > >> > > (fromhttp://en.wikipedia.org/wiki/CMBR) >> >> > >> > > By measuring the amount of the dipole anisotropy (the bluest >> > >> > > part of the sky is .0033 K hotter than average), we can >> > >> > > determine >> > >> > > the magnitude of the earth's motion with respect to the CMB: >> > >> > > the earth is moving at a speed of 370 km/s in the direction >> > >> > > of the constellation Virgo. >> > >> > > (fromhttp://www.phy.duke.edu/~kolena/cmb.htm) >> >> > >> > > It (the CMBR) does move with respect to an object. >> > >> > > (from PD <thedraperfam...(a)gmail.com>, Sep 5, 2009) >> >> > >> > > Clearly, the Earth moves wrt the CMBR. According to SR, >> > >> > > reciprocally, the CMBR moves wrt the Earth. >> > >> > > Can somebody explain how, physically, an electromagnetic >> > >> > > radiation filling the universe can move relative to the Earth? >> >> > >> > > Marcel Luttgens >> >> > >> > I think you are confused about what relative motion means, Marcel. >> > >> > You >> > >> > have in your head that motion is an absolute statement, as in >> > >> > either >> > >> > something is in motion or it's not. This is not the case. >> >> > >> > If you have car and a stop sign and a fire hydrant, the car is in >> > >> > motion relative to the stop sign, and the stop sign is in motion >> > >> > relative to the car, and the fire hydrant is not in motion >> > >> > relative to >> > >> > the stop sign, and the stop sign is not in relative to the fire >> > >> > hydrant, and the fire hydrant is in motion relative to the car, >> > >> > and >> > >> > the car is in motion relative to the fire hydrant. >> >> > >> > I think you have it in your head that if you have two objects A >> > >> > and B >> > >> > and they are in relative motion, then this means that one of them >> > >> > is >> > >> > in motion and the other is not. As in, A is in motion relative to >> > >> > B, >> > >> > but B is not in motion relative to A. >> >> > >> No, what I have in my head is that if A is in motion relative >> > >> to the CMBR, it is impossible to physically demonstrate that >> > >> the CMBR moves wrt A. >> >> > >> Marcel Luttgens >> >> > >> > When you say that you don't believe the CMBR is in motion relative >> > >> > to >> > >> > the earth, I believe you think this because you somehow believe >> > >> > the >> > >> > CMBR is fixed and stationary in some absolute sense and so can't >> > >> > be in >> > >> > any kind of motion, relative or not. I don't know where you got >> > >> > this >> > >> > idea. >> >> > >> > PD >> >> > > You are right Marcel. CMBR conforms an absolute frame >> > > of reference in the sense that the sources that emitted >> > > those CMBR photons were so distant from us, that their >> > > respective angular positions have not changed a bit since >> > > the emission events to the absoption ones. >> >> > It is a frame, but nothing absolute about it. The physics of that >> > frame is >> > the same as any other. It is a significant frame (especially to >> > astronomers) >> >> > > I can rember a wonderful thread started by Henri Wilson >> > > in this very forum called "Why are the 'Fixed Stars' so FIXED?" >> > >http://groups.google.com/group/sci.physics.relativity/msg/82337144cdc... >> >> > Oh gawd, not Henry. He has some weird ideas, and an amazing lack of >> > understanding about physics, and ability to post untruths with >> > apparently no >> > remorse. >> >> So, you do not know what an absolute frame of reference is? I didn't say that at all >> I'll give you some notions about it. Trace an angular position >> in your nightsky. Now, try to guess some distant source of >> light in that very angular position that emitted a photon >> towards you. The more distant the source was, the better >> for your fixed frame. So, infinite distant sources define >> an absolute frame of reference. What the hell does that have to do with absolute reference frames? >> Finite but highly distant >> sources define a quasi-absolute frame of reference. No, they don't >> What has the CMBR of special? The laws of physiscs in >> a lab at rest in that frame would look simpler. No .. they would not change in the slightest >> Example, >> an atomic clock would tick at the fastest rate if it is at >> rest in that CMBR frame (dipole=0) No .. it would not, unless the lab was also at rest in the CMBR frame. In which case it would be measured to tick at the same rate as it does when both are moving in the CMBR frame.
From: mluttgens on 8 Sep 2009 18:34
On 8 sep, 14:28, "Inertial" <relativ...(a)rest.com> wrote: > "mluttgens" <mluttg...(a)orange.fr> wrote in message > > news:afd5827b-f14e-4a66-a511-8148bb696967(a)g19g2000yqo.googlegroups.com... > > > > > > > On 8 sep, 01:32, "Inertial" <relativ...(a)rest.com> wrote: > >> "mluttgens" <mluttg...(a)orange.fr> wrote in message > > >>news:523b7307-93cc-44c3-940e-8bd1f368776e(a)h13g2000yqk.googlegroups.com.... > > >> > On 7 sep, 14:22, "Inertial" <relativ...(a)rest.com> wrote: > >> >> "mluttgens" <mluttg...(a)orange.fr> wrote in message > > >> >>news:6e6cbfbb-70bb-4fa6-99c3-45f00c351fa7(a)w36g2000yqm.googlegroups.com... > > >> >> > On 7 sep, 01:59, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > >> >> >> mluttgens wrote: > >> >> >> > Can somebody explain how, physically, an electromagnetic > >> >> >> > radiation filling the universe can move relative to the Earth? > > >> >> >> Your descriptions are insufficiently precise. There is no such > >> >> >> thing > >> >> >> as > >> >> >> "The CMBR" -- the cosmic microwave background radiation is > >> >> >> comprised > >> >> >> of > >> >> >> myriads of photons moving in all directions. This is not a "thing" > >> >> >> in > >> >> >> any normal sense, it is a vast collection of photons. > > >> >> >> [For the purposes of this thread I'll ignore the quantum > >> >> >> aspects of photons.] > > >> >> >> What you are missing is the fact that measurement of "the earth's > >> >> >> motion > >> >> >> with respect to the CMBR" is really a measurement of the earth's > >> >> >> speed > >> >> >> relative to THE FRAME IN WHICH THE CMBR DIPOLE MOMENT IS ZERO [#]. > >> >> >> This > >> >> >> is not in any sense a "rest frame of the CMBR", because the CMBR is > >> >> >> myriads of photons NONE of which are at rest in any frame. This is > >> >> >> purely a statistical property of the collection of all the photons > >> >> >> comprising the CMBR. > > >> >> >> [#] Careful authors phrase it this way, not in the careless > >> >> >> way you did. I have been phrasing it as "the CMBR dipole=0 > >> >> >> frame" in this newsgroup for many years. > > >> >> >> It is rather remarkable that there is such radiation apparently > >> >> >> filling > >> >> >> the universe (it has been observed interacting with distant stars > >> >> >> and > >> >> >> galaxies). This is quite strong evidence in support of the big bang > >> >> >> cosmologies, and the synthesis known as the standard model of > >> >> >> cosmology. > >> >> >> There remain details still unknown, and some downright puzzles > >> >> >> (dark > >> >> >> matter, dark energy, ...). > > >> >> >> Tom Roberts > > >> >> > Thank you. > > >> >> I would have assumed it was taken from the context of talking about > >> >> frames, > >> >> and absolute frames in particular, that 'the CMBR' was referring to > >> >> what > >> >> is > >> >> sometimes called the CMBR rest frame (as described above by Tom). > > >> >> > Do you consider that claiming (like Paul Draper and others) > >> >> > that the CMBR moves wrt an object, makes sense? > > >> >> It makes as much sense as an object moving wrt the CMBR. > > >> > No, read what Tom Roberts said: > > >> I did .. read what I said > > >> > "The measurement of "the earth's motion with respect to the CMBR" > >> > is really a measurement of the earth's speed relative to THE FRAME > >> > IN WHICH THE CMBR DIPOLE MOMENT IS ZERO." > > >> That's right > > >> > He didn't say that the Earth has no motion wrt the CMBR, > > >> Neither did I > > > Then explain how the "radiation apparently filling the universe" > > can move wrt the Earth. > > If its radiation, it moves at c relative to us, and relative to any other > object. > > But the CMBR frame, the one we move at ~370km/s within, is the frame of > reference where the "CMBR DIPOLE MOMENT IS ZERO" (to quote Tom's caps from > above). We move at 370km/s relative to it, and so it moves at 370km/s > relative to us. Concretely, what could be such frame of reference? Marcel Luttgens > > Please try and understand the terminology and basic physics here. Its not > that hard |