SR/GR use absolute time to synchronize the GPS clocks with the ground clock.
in [Relativity]
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From: Peter Webb on 15 Apr 2010 11:02 Every inertial observer adopted the laws of physics of the absolute frame and that's why every inertial frame has the same laws of physics. _________________________________ If the laws of physics are the same in every inertial frame, what makes one of them the absolute frame?
From: Michael Moroney on 15 Apr 2010 12:05 kenseto <kenseto(a)erinet.com> writes: >On Apr 14, 3:47=A0pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) >wrote: >> kenseto <kens...(a)erinet.com> writes: >> The absolute rest frame, or preferred frame, is _defined_ as a reference >> frame where the laws of physics are different from those in other frames. >> It's "special" because it has its own special laws of physics. >So why can't you describe the differences in the laws of physics >between an inertial frame and an absolute frame? That's kind of like describing the difference between a rabbit and the Easter Bunny. While the properties of a rabbit are well known, what is the Easter Bunny like? Well, every little kid has their own vision of it, with many ideas similar to other kids' ideas. It could be anything, because it doesn't exist, although rabbits do. What is a mythical absolute frame like? Which one? Well, the most common mythical absolute frame is probably the one theorized where the luminiferous aether was stationary, which I guess had all directions appear identical. Non preferred frames had the aether in motion relative to it, so light from one direction (in the direction of aether flow) would behave differently than that from another direction (opposite the aether flow or right angles to it or something). I am not up on the old aether theory since modern physics has no need for it. >> Since SR states that all inertial reference frames have the same laws of >> physics, a special frame where the laws of physics are different cannot >> exist (or is non-inertial). That's why I stated an absolute frame cannot >> exist. >But every inertial observer adopted the laws of physics of the >absolute frame and yet you turn around and claim that the absolute >frame doesn't exist. It's like you claim your mother is not your >mother. No, you are using whatever you defined "absolute frame" to be, not how theoretical physics defines it. What is the frame you call the Absolute Frame? Perhaps it's the frame where a cosmic ray proton, moving at 0.9 c parallel to the north-south axis of Pluto, is stationary. Since that frame is an inertial frame, it can be used as a reference for physics. But to avoid confusion, how about if we call that frame (or whichever frame you call the "absolute frame") Seto's Frame or something, so people don't think we're discussing the absolute frame of aether theory or some other old theory. >All you do is making assertions. Every inertial frame adopt the laws >of physics of the absolute frame and that's why the laws of physics >are the same in every inertial frame. Well, the laws of physics do work if you refer things to that cosmic ray moving at 0.9c relative to Pluto, so that is true. The math is almost always easier if the observer uses the frame that's stationary relative to himself, however. >Every inertial observer adopted the laws of physics of the absolute >frame and that's why every inertial frame has the same laws of >physics. I don't see why any observer would ever adopt that cosmic ray's frame (remember, we'll call it Seto's Frame instead of the absolute frame from now on, to avoid confusion) when the math is so much easier if they use their own frame as a reference. Unless the observer was actually that cosmic ray proton.
From: jem on 16 Apr 2010 09:03 kenseto wrote: > On Apr 14, 3:47 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) >> Since SR states that all inertial reference frames have the same laws of >> physics, a special frame where the laws of physics are different cannot >> exist (or is non-inertial). That's why I stated an absolute frame cannot >> exist. > > But every inertial observer adopted the laws of physics of the > absolute frame and yet you turn around and claim that the absolute > frame doesn't exist. It's like you claim your mother is not your > mother. > In my left hand is a bag of marbles, one of which is bigger than all the others. In my right hand is another a bag of marbles, all of which are identical to the biggest marble in the left hand bag. Seto logic: All the marbles in the right hand bag are the biggest marble. Why? Because all of them have the unique properties of the biggest marble.
From: kenseto on 16 Apr 2010 11:03 On Apr 15, 11:02 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > Every inertial observer adopted the laws of physics of the absolute > frame and that's why every inertial frame has the same laws of > physics. > > _________________________________ > > If the laws of physics are the same in every inertial frame, what makes one > of them the absolute frame? The point is: no inertial frame is the absolute frame....but every inertial frame adopts the laws of physics of the absolute frame and that's why every inertial frames has the same laws of phyiscs. Ken seto
From: Sam Wormley on 16 Apr 2010 11:12
On 4/16/10 10:03 AM, kenseto(a)erinet.com wrote: > The point is: no inertial frame is the absolute frame....but every > inertial frame adopts the laws of physics of the absolute frame and > that's why every inertial frames has the same laws of phyiscs. > > Ken seto You are correct when you write "no inertial frame is the absolute frame" as there are no absolute reference frame of any kind. A postulate of special relativity is: "...same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good. We will raise this conjecture (the purport of which will hereafter be called the ``Principle of Relativity'') to the status of a postulate, ..." |