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From: Inertial on 19 May 2010 19:30 "Da Do Ron Ron" <ron_aikas(a)hotmail.com> wrote in message news:1e5a95e0-312d-431a-9822-3995e7355f0f(a)e28g2000vbd.googlegroups.com... > On May 17, 9:37 pm, "Inertial" <relativ...(a)rest.com> wrote: >> "Da Do Ron Ron" <ron_ai...(a)hotmail.com> wrote in >> messagenews:00cb267f-d23d-43d4-a877-28e163decae6(a)q23g2000vba.googlegroups.com... > >>>and the null result did not change anything about light, > >>it changed what was known about light > > Like what? Study up on the history of aether theory and of EMR if you don't know. The very fact that the result was unexpected meant there need to be a change in how light was understood. >>indeed, each such observer will find a different >>bogus length for one and the same such rod because >>each such observer's clocks are "synchronized" >>differently due to each such observer's different >>absolute speed through space. > >>They will be different .. but that doesn't make them >>'bogus' > > Are you agreeing that the differences are caused by the > observers' usage of absolutely asynchronous clocks? No .. read my post > If you are not agreeing to this, then what do you say is > the physical cause of the differences? It is due to different relative clock sync. No absolute required. You seem to be hung up on absolutes.
From: Tom Roberts on 19 May 2010 21:42 Da Do Ron Ron wrote: > On May 13, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: >> The intrinsic length of an object means the length that the object itself >> inherently has, without relation to anything else. That can only mean the >> length measured by a ruler held directly up to the object without slipping >> -- i.e. its proper length. > >> I repeat: this does not change if you think that objects do "shrink" due to >> their "absolute motion" -- the ruler and object will necessarily be >> affected the same, and the value obtained will still be correct. > > Of course, the ruler and the object will be samely affected, but this means > that the shrunken ruler now reads incorrectly. You sure use words funny. No wonder it's so difficult to communicate with you. Here you say "incorrectly" when you mean "correctly" -- that is, because as you say "ruler and the object will be samely affected", the ruler reads the CORRECT value for the intrinsic length of the object, using YOUR notions. > For example, a 10-meter ruler can still read 10 meters for an object that is > in fact now only 5 meters long. You are confused; this cannot possibly happen because the ruler is being held right against the object, so the ruler "now" reads the correct length of the object. THAT'S WHAT WE MEAN BY THESE WORDS. In this case, using YOUR notions, the length of the object measured this way is the intrinsic length of the object, independent of the "absolute motion" of ruler and object. And you assume "facts" not in evidence. If in this situation the ruler reads 10 meters, then that is IN FACT the length of the object. So the object cannot be "now only 5 meters long". As I said before, you repeatedly and continually confuse yourself by attempting to apply some poorly-thought-out notion that objects somehow "shrink" due to "absolute motion". You cannot even write two paragraphs in a row that are self-consistent, because you are so confused. > I took it for granted at the start of this thread that anyone who knows > anything about SR knew this. You are VERY confused. You seem to think that in SR rulers and objects have lengths that "vary" -- THEY DON'T. In SR the intrinsic (or proper) length of an object is invariant and is unchanged regardless of its rest frame or its motion relative to any frame or observer. Yes, some comic books that attempt to discuss SR use language like that -- they are WRONG. And because of this historical confusion, saying "proper length of an object" is better than "length of an object", but in the latter phrase no mention of some other frame or measurement is made, so it can only mean the "intrinsic length of the object", which is the same as its proper length. As I keep saying: in SR, "length contraction" is related to the PROJECTION of an object's length onto moving coordinates; it has NOTHING WHATSOEVER to do with the object itself "changing" length. It is the RELATIONSHIP between the object and the coordinates that changes due to relative motion, not the object itself, and not the rulers used to construct the coordinates. I always put "length contraction" in quotes, because it is not the object's length that is "contracting", it is the MEASUREMENT that "contracts". The ladder does NOT change when you rotate it to fit through a doorway; its RELATIONSHIP to the doorway changes. The object does NOT change when it is moving relative to an observer's coordinates; its relationship to those coordinates changes -- relative motion is an hyperbolic ROTATION directly analogous to the rotation of the ladder. > [...] Do you get it now? It's you who does not "get it". >> Because in SR a frame moving relative to the object will PROJECT the >> object's length differently onto the moving frame than onto the object's >> rest frame, and thus the value obtained for the PROJECTION will be >> different from its proper length. In SR, the length of an object measured >> in a given frame is always the proper length of the object PROJECTED onto >> the measurement >frame. > > All this talk about "projection" evades the issue. That's your problem. You are unable to grasp that this projection does not "evade" the issue, it _IS_ the way this works in SR. Your personal failure to understand this does not affect SR itself -- you must LEARN what the theory ACTUALLY says. > Why not just say that different observer's get different "lengths" for a > "moving" rod because their absolutely asynchronous clocks cannot pin down or > locate the rod's end points truly simultaneously? We don't say that, because it is just plain wrong. > [... further nonsense based on the same confusions, errors, and mistakes.] There's no point in continuing. Tom Roberts
From: Sue... on 19 May 2010 21:54 On Apr 19, 1:59 pm, Da Do Ron Ron <ron_ai...(a)hotmail.com> wrote: > The math of the Michelson-Morley experiment (MMx) was based on the > following two facts: > > (i) light's speed in vacuo never varies (due to its source > independency) > (ii) the value of this speed is known to be c (from Maxwell's > equations) > > Given these simple facts, the time t along the horizontal leg must be > t = (2L/c)(1/(1-v^2/c^2)), whereas the vertical leg time t' must be > t' = (2L/c)(1/sqrt(1-v^2/c^2)), a time that is shorter than t. (v is > of > course Earth's unknown speed in space, which cannot be zero except > for a brief period each year). > > As we all know, the MMx consists of essentially only two things, > viz., > (a) the apparatus in space, and (b) light waves in space; therefore, > in > order for the above result NOT to occur, at least one of these two > things > must change. ================================= > > As we all also know, the above facts about light did not change; > thus, > something about the MMx apparatus had to change. > > The only way to change the above math is by making the MMx legs > different. > > Again, the only way to show the MMx null result on paper is by making > the legs different. > > This cannot be done by some outside observer viewing the legs; it can > only be done by a physical change of leg length(s). > > The above is proof of a physical change of length for one or both > legs. I wonder if a meteorologist arrives at that conclusion when there is no wind blowing through the same device: http://en.wikipedia.org/wiki/Anemometer#Sonic_anemometers See also: http://en.wikipedia.org/wiki/Lorentz_ether_theory#Principle_of_relativity Sue... > > ~~RA~~
From: Inertial on 19 May 2010 22:01 "Tom Roberts" <tjrob137(a)sbcglobal.net> wrote in message news:FvydnTf4XejxDmnWRVn_vwA(a)giganews.com... > Da Do Ron Ron wrote: >> On May 13, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: >>> The intrinsic length of an object means the length that the object >>> itself inherently has, without relation to anything else. That can only >>> mean the length measured by a ruler held directly up to the object >>> without slipping -- i.e. its proper length. >> >>> I repeat: this does not change if you think that objects do "shrink" due >>> to >>> their "absolute motion" -- the ruler and object will necessarily be >>> affected the same, and the value obtained will still be correct. >> >> Of course, the ruler and the object will be samely affected, but this >> means that the shrunken ruler now reads incorrectly. > > You sure use words funny. No wonder it's so difficult to communicate with > you. > Here you say "incorrectly" when you mean "correctly" -- that is, because > as you > say "ruler and the object will be samely affected", the ruler reads the > CORRECT > value for the intrinsic length of the object, using YOUR notions. > >> For example, a 10-meter ruler can still read 10 meters for an object that >> is in fact now only 5 meters long. > > You are confused; this cannot possibly happen because the ruler is being > held > right against the object, so the ruler "now" reads the correct length of > the > object. THAT'S WHAT WE MEAN BY THESE WORDS. In this case, using YOUR > notions, > the length of the object measured this way is the intrinsic length of the > object, independent of the "absolute motion" of ruler and object. > > And you assume "facts" not in evidence. If in this situation the > ruler reads 10 meters, then that is IN FACT the length of the > object. So the object cannot be "now only 5 meters long". > > As I said before, you repeatedly and continually confuse yourself by > attempting > to apply some poorly-thought-out notion that objects somehow "shrink" due > to > "absolute motion". You cannot even write two paragraphs in a row that are > self-consistent, because you are so confused. It depends on whether you are talking about SR or LET. Though both theories predict the same measurements, LET says this is due to both co-moving ruler and object both physically absolutely shrinking by the same amount (and clocks running absolutely slower and clocks getting absolutely out of sync) due to their motion through an aether (which is somehow able to make all objects shrink and all processes slow when things move through it). In SR there is no shrinking, and no absolute length, time, or sync involved. However, both LET and SR predict that relatively moving observers will measure a shorter spatial distance between two events than a co-moving observer will measure. In SR this is due to how spacetime behaves (which is as modeled by a projection using Minkowski geometry). In LET it is due to how the 'distorted' measurements of space and time relate (with the same geometry as SR). In both LET and SR, all observers will calculate the same proper length (interval) and this will be the same as the length measured by a commoving ruler. DDRR seems to be confusing the two theories.
From: Sue... on 19 May 2010 23:06
On May 19, 10:01 pm, "Inertial" <relativ...(a)rest.com> wrote: > "Tom Roberts" <tjrob...(a)sbcglobal.net> wrote in message > > news:FvydnTf4XejxDmnWRVn_vwA(a)giganews.com... > > > > > Da Do Ron Ron wrote: > >> On May 13, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > >>> The intrinsic length of an object means the length that the object > >>> itself inherently has, without relation to anything else. That can only > >>> mean the length measured by a ruler held directly up to the object > >>> without slipping -- i.e. its proper length. > > >>> I repeat: this does not change if you think that objects do "shrink" due > >>> to > >>> their "absolute motion" -- the ruler and object will necessarily be > >>> affected the same, and the value obtained will still be correct. > > >> Of course, the ruler and the object will be samely affected, but this > >> means that the shrunken ruler now reads incorrectly. > > > You sure use words funny. No wonder it's so difficult to communicate with > > you. > > Here you say "incorrectly" when you mean "correctly" -- that is, because > > as you > > say "ruler and the object will be samely affected", the ruler reads the > > CORRECT > > value for the intrinsic length of the object, using YOUR notions. > > >> For example, a 10-meter ruler can still read 10 meters for an object that > >> is in fact now only 5 meters long. > > > You are confused; this cannot possibly happen because the ruler is being > > held > > right against the object, so the ruler "now" reads the correct length of > > the > > object. THAT'S WHAT WE MEAN BY THESE WORDS. In this case, using YOUR > > notions, > > the length of the object measured this way is the intrinsic length of the > > object, independent of the "absolute motion" of ruler and object. > > > And you assume "facts" not in evidence. If in this situation the > > ruler reads 10 meters, then that is IN FACT the length of the > > object. So the object cannot be "now only 5 meters long". > > > As I said before, you repeatedly and continually confuse yourself by > > attempting > > to apply some poorly-thought-out notion that objects somehow "shrink" due > > to > > "absolute motion". You cannot even write two paragraphs in a row that are > > self-consistent, because you are so confused. > > It depends on whether you are talking about SR or LET. > > Though both theories predict the same measurements, LET says this is due to > both co-moving ruler and object both physically absolutely shrinking by the > same amount (and clocks running absolutely slower and clocks getting > absolutely out of sync) due to their motion through an aether (which is > somehow able to make all objects shrink and all processes slow when things > move through it). In SR there is no shrinking, and no absolute length, > time, or sync involved. > ============== > However, both LET and SR predict that relatively moving observers will > measure a shorter spatial distance between two events than a co-moving > observer will measure. In SR this is due to how spacetime behaves (which is > as modeled by a projection using Minkowski geometry). In LET it is due to > how the 'distorted' measurements of space and time relate (with the same > geometry as SR). In both LET and SR, all observers will calculate the same > proper length (interval) and this will be the same as the length measured by > a commoving ruler. No... Einstein's relativity (~1918 with Minkowski) does not predict this. That is why the "Bell's Spaceship quacks refuse to show their work with four-vectors. It breaks the parlour trick. If the imaginaries and reals are preserved with the imaginary operato or in the tensor calculus they can be recovered so that temporal and spatial components are not mixed improperly. http://farside.ph.utexas.edu/teaching/em/lectures/node113.html http://farside.ph.utexas.edu/teaching/em/lectures/node115.html > > DDRR seems to be confusing the two theories. I'm shocked, shocked to find that confusion is going on in here! Sue... |