A little drunk and painkilled now, so please bear that in mind. Broke two ribs last week. Ouch. Not so bad now though.
On 05/08/14 13:12, Ian Woollard wrote:
On 5 August 2014 12:05, Peter Fairbrother <zenadsl6186@xxxxxxxxx <mailto:zenadsl6186@xxxxxxxxx>> wrote: According to the cosmic background dipole, "369±0.9 km/s relative to the reference frame of the CMB (also called the CMB rest frame, or the frame of reference in which there is no motion through the CMB) in the direction of galactic longitude l = 263.99±0.14°, b = 48.26±0.03°" wikipedia, "Cosmic microwave background", "CMBR dipole anisotropy" http://en.wikipedia.org/wiki/Cosmic_microwave_background#CMBR_dipole_anisotropy Sure, they're measuring the average speed of the universe. BTW, it continues: "From a theoretical point of view, the existence of a CMB rest frame breaks Lorentz invariance even in empty space far away from any galaxy." That bit is quite wrong. The cosmic background radiation certainly establishes A reference frame, but it doesn't have different physics. Establishing reference frames is trivially done, in many different ways. The Earth is a reference frame, and we can launch things using that, because you can touch it in various ways. It doesn't violate Lorentz invariance either. For that the laws of physics have to prefer it in some sense. They don't.
If there is a frame everyone can separately agree on - and by separately agree, I mean they can't eg all pre-agree it's say zero relative to a particular star or galaxy or whatever, but independently come to the same conclusion that there is a frame relative to the big bang itself, the creation of space-time, without ever talking to each other, but just from observing the universe - then, if only from an information-theory point of view, invariance is toast.
[ the big bang is, iirc, located about 350,000 ly beyond the surface where the cosmic microwave background comes from, with fairly exactly the same separation in pretty much every direction - so the zero of the big bang frame's zero is pretty much the same as the microwave background frame's zero.
I think (though I may be corrected) that the total momentum of the universe's zero is exactly the same as the big bang zero.
That's a pretty big zero. ]mind you the circumstances in which invariance have been experimentally "proven" pretty much actually only prove much lesser things - like if there is an aetheric wind the electromagnetic bond between two atoms is equally as affected by it as the electromagnetic wave of a beam of light.
I don't think anyone has ever actually experimentally proven that there is no "aetheric wind".
So far as is known, there's no quantum mechanical reference frame that you can push things along at rest with the matter in the universe. THAT would violate Lorentz invariance pretty much for sure.
Agreed, and agreed.But we do not know enough to prove there isn't. We can say we haven't noticed one (?much) yet, but that doesn't say any more than it says
-- Peter F