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From: GogoJF on 10 Aug 2010 18:23 On Aug 7, 10:47 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > GogoJF wrote: > > On Aug 5, 2:31 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > >> Nature uses no observers, so valid models of physics must not use observers, or > >> at least be independent of observer. > > > So, you say that all our models should be devoid of the > > observer, in order to measure nature correctly- that we should, > > instead, use our devices which are more precise and accurate? > > Hmmm. You can read what I said above. That's what I said. This is not about > precision or accuracy, it is about faithfully modeling nature. > > Our models must, of course, include measuring devices, and must model the > measurement process. > > For instance, in GR to model the length that a ruler measures, > one integrates the metric along the spacelike path of the ruler. > To model the time interval displayed on a clock, one integrates > the metric along the clock's timelike path. > > > At the > > same time, this statement disqualifies all observational measure. > > No. It merely points out that the observer is not part of the model. > Measurements are included in the model. > > > Einstein's description of relativity routinely uses the observer in > > the thought experiment. > > Sure. But you must understand what his observers did -- they applied measurement > instruments, nothing more. So modeling those instruments is sufficient. This was > the literary style of his day, and it persists to today, but there is no need > for a human observer, or any other kind of observer; modeling the instruments is > sufficient. > > This is not true for the Copenhagen interpretation of quantum > mechanics. That IMHO is a fatal flaw. > > Tom Roberts Does not the observers' apparatus "mimic" the "applied measurement instrument"? I think there is room for clarity here. You imply that this "literary style" that we speak of today- this Einstein thought experiment kind-of-way of thinking is necessary in discussion but not needed in real matters of "modeling of instruments". Cannot an observer pick up a stop watch and become some kind of crude measuring device?
From: harald on 11 Aug 2010 04:06
On Aug 10, 8:00 pm, Da Do Ron Ron <ron_ai...(a)hotmail.com> wrote: > from Harald: > > >http://en.wikipedia.org/wiki/Walter_Kaufmann_%28physicist%29 > > Relativistic "mass variance" does not support SR Did you actually *see* what you wrote?? Effectively you state here that an effect predicted by the Special theory of Relativity does not support the Special theory of Relativity. > because it is merely > an observer-dependent triviality. You base a self contradictory conclusion on your statement that "it is merely an observer-dependent triviality". Evidently that statement of yours is erroneous; and you already *knew* that your statement is erroneous from my citations. > It cannot physically exist because > it is reciprocal (i.e., each of two passing objects cannot both be > truly more massive than each other). I already explained that this is the same for classical kinetic energy. As you would put it: Each of two passing objects cannot both have truly more kinetic energy than each other. Therefore it cannot physically exist. Your conclusion *must* therefore be that kinetic energy, as "does not support" classical mechanics. > On the other hand, any actual or physical > mass variance would contradict SR due to the fact that it involves > true or absolute motion. As you don't even see what you write yourself, it should not be surprising that you also did not see me prove the contrary... Once more, with a little addition: As Einstein stated in 1907, the theory (which he would later brand "Special relativity") is the "merger of the H. A. Lorentz Theory" (of 1895) "and the relativity principle", as developed by Lorentz in 1904 and by himself in 1905 (he omitted Poincare, but that's another topic). I already cited for you two other passages of that same paper: (with a little rearrangement:) "H. A. Lorentz's and FitzGerald's hypothesis [according to which moving bodies experience a certain contraction in the direction of their motion] appear [..] as a compelling consequence of [relativity] theory." and: "It is by no means self-evident that the assumption made here which we call "the principle of the constancy of the velocity of light" is actually realized in nature, but --at least for a coordinate system in a certain state of motion-- it is made plausible by the confirmation through experiment of the Lorentz theory [of 1895], which is based on the assumption of an ether that is absolutely in rest." - http://www.soso.ch/wissen/hist/SRT/E-1907.pdf Now explain to me how true or absolute motion can contradict Special Relativity! (I won't bother to reply anymore if you don't). [more of the same] > Harald quoted: > "If one of two synchronous clocks at A is moved in a closed curve > with > constant velocity until it returns to A, the journey lasting t > seconds, then by the clock which has remained at rest the travelled > clock on its arrival at A will be 1/2tv² second slow." > > The problem with this is that acceleration is involved. That wasn't a problem for Lorentz or Einstein, nor is it for me. > I have eliminated > this problem with the following simple experiment: > > clock A > -----------------------------------<---[0]--- > ---------------------------------------[0]---> > clock B1 > > clock A > -------------------<---[4]--- clock B2 > ------------------------------------------------------<---[4]--- > ----------------------------------------------------------[4]---> > clock B1 > > clock A > ---<---[8]--- > ---<---[10]--- > clock B2 > > (Ref.: clocks B1 and B2 both move at 0.6c relative to clock A) If [8] and [10] are clock readings then you apparently made a calculation error (in fact B2 will be retarded on A). > The above extremely simple experiment directly proves that clocks in > different inertial frames run at physically different rates. > It also > proves that people in different such frames age differently. SR has > no explanation for these facts. SR makes no physical predictions re > any fundamental physical phenomena. SRT predicts many *physical phenomena*, which are what is *observed*. Check the dictionary: "a fact, occurrence, or circumstance observed or observable: to study the phenomena of nature" "of or pertaining to that which is material" - http://dictionary.reference.com Harald |