jlg@lanl.ARPA (Jim Giles) (03/17/86)
In article <12400@ucbvax.BERKELEY.EDU> weemba@brahms.UUCP (Matthew P. Wiener) writes: >... The fact that Alpha Centauri is >seen moving slower than light in ONE frame means it moves slower than >light in ALL frames. This, of course, was EXACTLY my point. Alpha Centauri IS moving slower than light in ALL frames. Therefore, a coordinate system anchored the the Earth in NOT a 'frame' - which is what the Russell quote implies. Attaching vectors x0 - x4 to a rock and calling it a frame is NOT an application of relativity. J. Giles Los Alamos P.S. Why is 'name calling' a keyword for this discussion? I haven't called anyone any names yet. Neither has anyone called me any names. Or is it just left over from the subject 'Bogus Physics' which is different than this one: 'Bogus Physics reamplified'? Anyway, I am changing the subject line to 'GR and rotation'. I have also removed it from net.origins and removed the 'name calling' keyword.
weemba@brahms.BERKELEY.EDU (Matthew P. Wiener) (03/22/86)
In article <557@lanl.ARPA> jlg@a.UUCP (Jim Giles) writes: >In article <12400@ucbvax.BERKELEY.EDU> weemba@brahms.UUCP (Matthew P. Wiener) writes: >>... The fact that Alpha Centauri is >>seen moving slower than light in ONE frame means it moves slower than >>light in ALL frames. > >This, of course, was EXACTLY my point. Alpha Centauri IS moving slower >than light in ALL frames. Therefore, a coordinate system anchored the >the Earth in NOT a 'frame' - which is what the Russell quote implies. >Attaching vectors x0 - x4 to a rock and calling it a frame is NOT an ^^^^^^^ and he built a crooked house, eh? >application of relativity. What is this? Your argument to prove that attaching vectors etc. ... does not lead to a frame is completely bogus. You concluded that Alpha Centauri was moving 9490 times faster than light in the rotating frame, which no frame can allow, and therefore concluded it was not a frame. But in the rotating frame, your calculation does NOT show Alpha Centauri is moving faster than light, and so you CANNOT conclude that the rotating frame is not a frame. Reread my article to see what your calculation does show. For your information, a frame is nothing more than a coordinate system. I think you might be confused on this point because Misner Thorne and Wheeler never defined what a frame is in general. Try reading some other GR books for a change. Or better yet, actually DO some GR instead of yelping about it all the time. ucbvax!brahms!weemba Matthew P Wiener/UCB Math Dept/Berkeley CA 94720
jlg@lanl.ARPA (Jim Giles) (03/23/86)
In article <12546@ucbvax.BERKELEY.EDU> weemba@brahms.UUCP (Matthew P. Wiener) writes: >>Attaching vectors x0 - x4 to a rock and calling it a frame is NOT an > ^^^^^^^ and he built a crooked house, eh? >>application of relativity. I was expecting someone to nit-pit this! I didn't want to exclude anyone, so I gave the timelike dimension twice - once for the people who put it at x0 and one for those who keep it at x4. (:-) > >For your information, a frame is nothing more than a coordinate system. When I mean 'coordinate system' I say 'coordinate system'. I always use 'frame' as short for 'Lorentzian frame', and the geometry of spacetime is locally Lorentzian everywhere. I made this distinction pretty clear in my first submission. A rotating coordinate system is NOT a Lorentzian frame! It is the lack of this distinction which I objected to in the Russell quote, he implied that a rotating coordinate system was indistinguishable from a non-rotating one. Since this is not true (at least, you have yet to give ANY evidence or documentation supporting that view), I objected. >I think you might be confused on this point because Misner Thorne and >Wheeler never defined what a frame is in general. Try reading some other >GR books for a change. Or better yet, actually DO some GR instead of >yelping about it all the time. I AM reading other GR books, MTW just happens to be the most complete. I assumed that YOU didn't read or do GR since you never mention any problems, references, research, or facts to support your view. All you have done so far is spout high sounding terminology without any evidence that you understand it. Unlike you, I have tried to keep my submissions simple enough for the other readers of the net to follow, and then leave references for people to follow it up in more detail. Now, don't get me wrong. I don't claim that you don't know the subject, you just haven't given any evidence of it yet. I'm not unwilling to change my mind if presented with evidence and information instead of rhetoric. You don't really know a subject unless you can explain it clearly in layman's terms. Charles Greeley Abbott Former secretary of The Smithsonian Institution J. Giles Los Alamos P.S. I don't plan to continue this discussion unless new EVIDENCE is presented. If you can't stop yelping out rhetoric and begin a discussion in layman's terms, perhaps it's better to take the discussion off the net and just use email or not discuss it at all. Note: I have put 'name calling' back on the list of keywords to this discussion. An ad hominem attack is the last resort of one without further valid arguments. I'm sorry to see that Mr. Wiener saw fit to resort to it.
dbb@aicchi.UUCP (Burch) (03/26/86)
One good point to make is that a rotating frame is not an inertial frame. It is an accelerated frame, and one can determine by measurement... A ring laser gyro of sufficient sensitivity can detect the rotation of the earth as can simpler implements like foucault pendulums. An object's apparent velocity only makes sense in an inertial frame. -- -David B. (Ben) Burch Analyst's International Corp. Chicago Branch (ihnp4!aicchi!dbb) "Argue for your limitations, and they are yours"