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Natural Science Forum / Physics / Relativity / April 2006michelson morley experiment
Hi In the MM experiment, was the length of the two light paths set exactly equal. If so, how was this done? If not, did the experiment "rely" on the fact that there was no change in the interference fringes when the apparatus was rotated? Did the MM experiment demonstrate anything about the constancy of the speed of light or did it merely "disprove" the aether theory? Does this website have any credibility in mainstream physics? http://home.iprimus.com.au/longhair1/page1.html Thanks. > Hi > [quoted text clipped - 10 lines] > > Thanks. sure it has, thay say "This site is a proud member of The Theory of Everything Webring, linking the great thinkers of our time." what are you crazy > Hi > > In the MM experiment, was the length of the two light paths set > exactly equal. No. > If so, how was this done? If not, did the experiment > "rely" on the fact that there was no change in the interference > fringes when the apparatus was rotated? Instead it relied on the assumption that there would be a significant change - which turned out to be absent. > Did the MM experiment demonstrate anything about the constancy of the > speed of light or did it merely "disprove" the aether theory? It demonstrated the constrancy of the measured return speed of light, thus disproving Maxwell's ether theory. > Does this website have any credibility in mainstream physics? > http://home.iprimus.com.au/longhair1/page1.html I don't know it; at first sight it certainly doesn't look credible . > Thanks. You're welcome. > > Hi > > > > In the MM experiment, was the length of the two light paths set > > exactly equal. > > No. Pretty nearly equal, though. Although Michelson and Morley used sodium light for collimating the apparatus, the actual experiment was performed using white light from an argand burner. The colored fringes were much easier to visually monitor; on the other hand, the limited coherence length of white light meant that the path lengths needed to match within microns. Note in Fig. 4 the piece of glass "c" used to compensate for the difference in light paths. http://www.aip.org/history/gap/PDF/michelson.pdf > > If so, how was this done? If not, did the experiment > > "rely" on the fact that there was no change in the interference [quoted text clipped - 8 lines] > It demonstrated the constrancy of the measured return speed of light, thus > disproving Maxwell's ether theory. In an effort to "save" aether theory, of course, various ad hoc hypotheses were made including the notion that the aether might be entrained by the moving Earth, or the totally ad hoc Lorentz- Fitzgerald contraction, later derived by Einstein. > > Does this website have any credibility in mainstream physics? > > http://home.iprimus.com.au/longhair1/page1.html [quoted text clipped - 4 lines] > > You're welcome. Jerry > > > Hi > > > [quoted text clipped - 11 lines] > of glass "c" used to compensate for the difference in light paths. > http://www.aip.org/history/gap/PDF/michelson.pdf Yes indeed, interesting! > > > If so, how was this done? If not, did the experiment > > > "rely" on the fact that there was no change in the interference [quoted text clipped - 13 lines] > be entrained by the moving Earth, or the totally ad hoc Lorentz- > Fitzgerald contraction, later derived by Einstein. That that contraction was ad hoc was a misunderstanding by Einstein, and some textbooks continue to propagate that fable. The idea started with Fitzgerald inferring it from Heaviside's EM field calculations; Lorentz and Poincare showed independently that it must be a length contraction by a factor gamma. Indeed, Lorentz admitted that he should have made clearer that it was not "ad hoc", and agreed that Einstein's derivation was more elegant. Harald > > > Does this website have any credibility in mainstream physics? > > > http://home.iprimus.com.au/longhair1/page1.html [quoted text clipped - 6 lines] > > Jerry > > Does this website have any credibility in mainstream physics? > > http://home.iprimus.com.au/longhair1/page1.html That is a net version of a book written by two Australian physicists in 2001. Do books of psysics have any credibility? At least it looks like a professional work. Henry Haapalainen > > > Does this website have any credibility in mainstream physics? > > > http://home.iprimus.com.au/longhair1/page1.html [quoted text clipped - 4 lines] > > Henry Haapalainen I saw only one author mentioned, on the front page. Where did you find that it's "written by two Australian physicists "? > Hi > [quoted text clipped - 5 lines] > Did the MM experiment demonstrate anything about the constancy of the > speed of light or did it merely "disprove" the aether theory? It disproved the 'simple' aether theory oft the day. > Does this website have any credibility in mainstream physics? > http://home.iprimus.com.au/longhair1/page1.html No. Martin Hogbin | Hi | | In the MM experiment, was the length of the two light paths set | exactly equal. No, and it doesn't need to be. All that is required is a wavelength match. | If so, how was this done? With adjusting screws of the type used in micrometers. http://tinyurl.com/h2g7z If not, did the experiment | "rely" on the fact that there was no change in the interference | fringes when the apparatus was rotated? | | Did the MM experiment demonstrate anything about the constancy of the | speed of light or did it merely "disprove" the aether theory? It only disproved aether. The wind when you put your hand out of a car window proves the world is moving. Close the window and you won't feel it. http://tinyurl.com/f8a9z | Does this website have any credibility in mainstream physics? | http://home.iprimus.com.au/longhair1/page1.html Nope. Androcles | Thanks. >In the MM experiment, was the length of the two light paths set >exactly equal. They originally set it up that way. Of course, one can not have *exactly* same lengths but within error bars was the same length. Then other similar setups were done with different arm lengths. See Kennedy-Thorndyke. >If not, did the experiment >"rely" on the fact that there was no change in the interference >fringes when the apparatus was rotated? It did not *rely* on that fact. I was setup to find what would happen if rotated. >Did the MM experiment demonstrate anything about the constancy of the >speed of light or did it merely "disprove" the aether theory? It (as was already known) showed that the TWLS was constant. It did not disprove (modern) ehter theory because ether theory predicts that there would be no fringe shift. But the 'earlier' ether theory was badly interpreted and was thought that it it predicted a fringe shift. --- If you want to be sure, then always doubt }:-) >>In the MM experiment, was the length of the two light paths set >>exactly equal. [quoted text clipped - 18 lines] >that there would be no fringe shift. But the 'earlier' ether theory was >badly interpreted and was thought that it it predicted a fringe shift. So if I calculate the phase relationship between the two swimmers that are described here http://galileoandeinstein.physics.virginia.edu/lectures/michelson.html will I find any change if I "rotate the apparatus" i.e. if the direction of the current in the river is changed? If I change the direction of the current in the river, the two swimmers won't make it back to the original starting point unless I also change the direction they swim, but if I change the direction they swim, this is no longer the equivalent of the MM experiment, so the fact that the two swimmers make it back to the starting point at different times when the river is flowing parallel to the river bank, proves nothing ?? Since the MM apparatus doesn't change the direction the "swimmers" swim in, won't this produce a fringe shift as the apparatus is rotated, according to the ether theory being tested? Thanks The Earth is not the center of the universe. If there was a backround, the aether stayin still, there should be a difference of, at least, thousands of kilometres per second, when c is measured in different directions. An aether does not exist, and no more evidence is needed. Henry Haapalainen > >>In the MM experiment, was the length of the two light paths set > >>exactly equal. [quoted text clipped - 38 lines] > > Thanks > >>In the MM experiment, was the length of the two light paths set > >>exactly equal. [quoted text clipped - 38 lines] > > Thanks Do you think you need to aim a flashlight up stream to hit a target perpendicular to your direction of motion? Light doesn't work that way, so your analogy is flawed. Take a friend and a couple of megaphones out to a field on a windy day. Use your megaphone to shout to your friend while he uses his to determine the direction the sound comes from. You will find that he does not hear the sound come from up wind or down wind but straight from you. You will find it is best to aim straight at him, not up wind or down wind. So sound, which is carried by a medium, does not behave the way you predict either. It's not so easy to disprove the aether when you use what really happens as opposed to poor analogies. Bruce Richmond >> >>In the MM experiment, was the length of the two light paths set >> >>exactly equal. [quoted text clipped - 42 lines] >perpendicular to your direction of motion? Light doesn't work that >way, so your analogy is flawed. It's not my analogy. Judging by the URL, the University of Virginia physics department is responsible for the analogy. Since I didn't get an answer to my question about the siwmmers and the river that made any sense to me I will assume that the analogy with the swimmers and the river is meaningless and the crucial details about the MM experiment are not explained on that web page. Darkknight. >Take a friend and a couple of megaphones out to a field on a windy day. > Use your megaphone to shout to your friend while he uses his to [quoted text clipped - 8 lines] > >Bruce Richmond > >> http://galileoandeinstein.physics.virginia.edu/lectures/michelson.html > It's not my analogy. Judging by the URL, the University of Virginia > physics department is responsible for the analogy. [quoted text clipped - 3 lines] > the swimmers and the river is meaningless and the crucial details > about the MM experiment are not explained on that web page. What I see in the above URL is a fairly standard explanation of the rationale behind the MMX. You could try reading the original paper, reproduced in full at the bottom of this page: http://www.aip.org/history/gap/Michelson/Michelson.html There are lots of other of historically important papers to be found at the above web site. Jerry > >> >>In the MM experiment, was the length of the two light paths set > >> >>exactly equal. [quoted text clipped - 50 lines] > the swimmers and the river is meaningless and the crucial details > about the MM experiment are not explained on that web page. As you have read below (you did, right?), such an analogy is no good for questions relating to momentum conservation. The analogy was only intended (but never proved!) to be valid for calculating the propagation *speed* of a wave that propagates through a moving medium. Assuming that it's indeed valid for a wave that is skewed relative to the medium, then you get the factor gamma for the total time delay, and gamma^2 for 0/180 degrees. The difference is a factor gamma, and that's what M-M expected to be able to measure. Harald > >Take a friend and a couple of megaphones out to a field on a windy day. > > Use your megaphone to shout to your friend while he uses his to [quoted text clipped - 8 lines] > > > >Bruce Richmond The analogy os almost correct. That analogy/explanation was the early view of ether theories. In modern ether theories (Lorentz etc..), one should not use the concept of 'ether wind'. One should view the ether (the river) as the 'fixed' medium and that it is the rest of the stuff that is moving wrt the ether. So the analogy should be that the river flow is not flowing but the sidebanks (and swimers) are moving. In modern ether theories, when an object (sidebank and the swimers...) travels within the river (ether), their lenghts are contracted (so is their clock ticks) in the direction of motion. It is these length and time contractions that cancel out the supposedly fringe shift in the MMexperiment. The swimmners will always arrive together when they return. Note that the swimmers should always swim at constant speed wrt the river for the analogy to be complete (light is always c in the ether frame). --- If you want to be sure, then always doubt }:-) > Take a friend and a couple of megaphones out to a field on a windy day. > Use your megaphone to shout to your friend while he uses his to > determine the direction the sound comes from. You will find that he > does not hear the sound come from up wind or down wind but straight > from you. You will find it is best to aim straight at him, not up wind > or down wind. I think you will not be able to measure the angle accurately enough. Even for 60 MPH wind the angle is less than 5 degrees. And of course in such a wind your friend would not hear you (or even be able to hold a megaphone).... Theoretically for this case and transverse wind, you (the speaker) must point upwind by arcsin(windspeed/soundspeed); your friend (the receiver) must point directly at the speaker, not upwind or downwind. This is also the case for launching a motorboat across a river -- it must be aimed/steered upriver to arrive transversely at a point opposite from its starting point. With light, we find no evidence of any motion that must be compensated for, and a directional source always points directly at the receiver, and vice versa (assuming source and detector are at rest in some inertial frame). > It's not so easy to disprove the aether when you use what really > happens as opposed to poor analogies. "easy", no. But it has been done, for all known aether theories except those that happen to be experimentally indistinguishable from SR. By literally hundreds of different experiments [see the FAQ for references]. Tom Roberts tjroberts@lucent.com [snip] > Theoretically for this case and transverse wind, you (the speaker) must > point upwind by arcsin(windspeed/soundspeed); your friend (the receiver) [quoted text clipped - 7 lines] > and vice versa (assuming source and detector are at rest in some > inertial frame). I believe this is an important issue and one that I have been considering in relation to the laser experiments done by H. Webster Kehr. Tom, would you agree that if you have a stationary laser on the surface of the Earth pointing at a stationary target on the surface of the Earth, that irrespective of the motion of the Earth at approximately 370 kilometers per second linearly towards the constellation Leo, as evidenced by the CMBR, the laser beam would still be pointed directly at the target in order to hit it and the laser beam does not leave the laser at an angle? Thanks, Vern >[snip] > [quoted text clipped - 19 lines] >be pointed directly at the target in order to hit it and the laser beam >does not leave the laser at an angle? I believe Tom meant that the direction the source points does not have to allow for any "sideways" motion of the light during its journey. The laser would have to be aimed differently at different times of the year. It is pointed at where the receiver will be when the light arrives at the destination, not at where the receiver was when the light left the source. If the laser beam hits the target at exactly 90 degrees then it won't bounce off at an angle, assuming a perfectly smooth reflector, however the path of the laser beam will be at an angle to the instantaneous line between the source and destination at the time the light left the laser. http://www.teslaphysics.com/Chapters/Chapter070-SecularAberration.htm > >[snip] > > [quoted text clipped - 33 lines] > > http://www.teslaphysics.com/Chapters/Chapter070-SecularAberration.htm I see you have referenced Kehr's writings. What did you think of the paradox he points out? Is there a better term to use than "path momentum" to describe the paradox? It seems that Kehr is saying that because of aberration we can assume that both starlight and terrestial light move independently of the motion of their sources. This is also a postulate in relativity. However, if that is true then a laser experiment where the laser beam is at approximately 30-40 degrees n. latitude and shot at a target every hour for 24 hours should yield an eclipse pattern. Is does not, but rather always hits the same spot. Therefore, the laser must impart momentum to the beam meaning it leaves the laser at an angle and the speed of the beam must vary. That contradicts what Tom said. Vern >> The laser would have to be aimed differently at different times of the >> year. It is pointed at where the receiver will be when the light [quoted text clipped - 18 lines] >every hour for 24 hours should yield an eclipse pattern. Is does not, >but rather always hits the same spot. Which experiment was this, how, when and where was it done and where is it documented? Darkknight. > Therefore, the laser must impart >momentum to the beam meaning it leaves the laser at an angle and the >speed of the beam must vary. That contradicts what Tom said. > >Vern [snip] > >I see you have referenced Kehr's writings. What did you think of the > >paradox he points out? Is there a better term to use than "path [quoted text clipped - 10 lines] > Which experiment was this, how, when and where was it done and where > is it documented? You can download Kehr's "book" at the website below: http://www.teslaphysics.com/ He evidently worked for a large telecommunications company which was finding that there was interference in fiber-optic cables similar to the company that DeWitt worked for. Anyway, Kehr convinced his company to give him some money to do laser experiments, as I outlined above. The experiments he did are explained in detail in his "book." The interesting thing about the experiments is that they don't try to measure the speed of light, so the usual arguments about length contraction, time dilation, synchronizing clocks, LET vs. SR, etc. don't come into play. Instead they are based on Newtonian mechanics principles and whether light has ballistic properties. Using terrestial light sources, the experiment should have revealed the full effect of secular aberration, but instead it is consistent with a model of light which is a wave in an aether where the aether is like a bubble around the Earth and the Earth's rotation on its axis does not affect the aether. This corresponds with explanations for H-K type experiments and GPS, where an Earth-axis-centered frame is used for measurements. Vern > I believe this is an important issue and one that I have been > considering in relation to the laser experiments done by H. Webster [quoted text clipped - 5 lines] > be pointed directly at the target in order to hit it and the laser beam > does not leave the laser at an angle? In the frame of the earth surface at the location of the laser, the light leaves the laser straight down its centerline. Insofar as the non-inertial motions of the earth can be neglected during the flight time of the light, the image at the target will remain motionless, 24 hours a day 365 days a year (assuming true stability in mounting and the optical path). Indeed, since the non-inertial motions of the earth are so steady, they will be accounted for during setup, and it's really the variation in them that matters (e.g. the beating between rotational and orbital motion). That 370 km/s is roughly 0.001 times the speed of light, and the angle relative to the CMBR dipole=0 frame varies diurnally -- people would notice if light danced around by that milliradian as the earth turned: surveying over just 10 meters would be off by a cm! This does not happen. Tom Roberts tjroberts137@sbcglobal.net >> I believe this is an important issue and one that I have been >> considering in relation to the laser experiments done by H. Webster [quoted text clipped - 8 lines] >In the frame of the earth surface at the location of the laser, the >light leaves the laser straight down its centerline. Then why do telescopes have to be "tilted" to account for stellar aberration? i.e. the line of the telescope has to be at a very slight angle to the line of the light. >Insofar as the non-inertial motions of the earth can be neglected during >the flight time of the light, the image at the target will remain [quoted text clipped - 8 lines] >notice if light danced around by that milliradian as the earth turned: >surveying over just 10 meters would be off by a cm! This does not happen. I don't understand. If the light path of the laser is at right angles to the 400 km per second motion of the earth, then over a distance of 1 km, the laser takes 1/300000 seconds to reach the target, during which time the target has moved by (1/300000) * 400 km - which is .001333 km - equals 130 cm. (or 1cm over 10 metres as you say). If the light path of the laser is parallel to the direction of motion (which it could be after 8 hours) then the target hasn't moved so a difference of 1 cm would be seen on the "strike point" at the target. I'm sure you're right coz I know next to nothing about physics but why doesn't the "strike point" move? Darkknight. Dear darkknight: ... >>In the frame of the earth surface at the location of >>the laser, the light leaves the laser straight down [quoted text clipped - 4 lines] > telescope has to be at a very slight angle to the > line of the light. No. The telescope has to be *inline* with the light. http://en.wikipedia.org/wiki/Aberration_of_starlight ... just that "inline" varies. David A. Smith On Sun, 16 Apr 2006 16:29:21 -0700, "N:dlzc D:aol T:com \(dlzc\)" <N: dlzc1 D:cox T:net@nospam.com> wrote: >Dear darkknight: > [quoted text clipped - 11 lines] >http://en.wikipedia.org/wiki/Aberration_of_starlight >... just that "inline" varies. Thanks. I got confused by the analogy with a narrow bucket and rain, where the bucket has to be at an angle to the path of the rain for the raindrops to hit the bottom of the bucket and the angle changes according to the speed of the bucket. However, my understanding of stellar aberration is still zero and I have no clue how astronomers can even tell the position of a star has "changed" or what that means. I would have thought the "position" of a star was equivalent to the angle at which the light from the star strikes the earth - which is affected by the tilt of the earth and the time of day so how could you tell the position didn't change due to that. And apart from that, if the relative positions of the star and the earth are changing due to motion of the galaxies or the stars within the galaxies then that is going to cause the star's position to change all the time. I don't see how a change from 340 km/second to 400 km/second is going to be the cause of a change in position of the star - but then I don't know how you measure the position of a star in the first place. I'm supposed to be intelligent but I can hardly understand anything ... (anyway, no need to waste time trying to explain. I'm sure I can find a book on it somewhere - yep I did read the Wikipedia article (for the second time) but I still don't understand). Darkknight Dear darkknight: > On Sun, 16 Apr 2006 16:29:21 -0700, "N:dlzc D:aol T:com > \(dlzc\)" <N: [quoted text clipped - 31 lines] > the time of day so how could you tell the position > didn't change due to that. It is an effect *in addition to* that. That is how precisely you have to measure things. > And apart from that, if the relative positions of > the star and the earth are changing due to motion > of the galaxies or the stars within the galaxies > then that is going to cause the star's position to > change all the time. Yes, it does. > I don't see how a change from 340 km/second to > 400 km/second is going to be the cause of a > change in position ... "apparent position" ... > of the star - but then I don't know how you measure > the position of a star in the first place. Likely the same way as surveyors measure(d) the surface of the Earth (before GPS). Like how they notice very tiny changes in elevation of important markers due to the depletion of underground aquifers (subsidence). > I'm supposed to be intelligent but I can hardly > understand anything ... Patience. > (anyway, no need to waste time trying to explain. > I'm sure I can find a book on it somewhere - yep I > did read the Wikipedia article (for the second > time) but I still don't understand). The answer will come when you are ready for it. Good luck. David A. Smith > On Sun, 16 Apr 2006 16:29:21 -0700, "N:dlzc D:aol T:com \(dlzc\)" <N: > dlzc1 D:cox T:net@nospam.com> wrote: [quoted text clipped - 39 lines] > > Darkknight The poor relativists are now restricted to aether and Maxwell but cannot help themselves and run all the way back to Newton insofar as there is a big feedback loop between the exotic 1905 concept and Newtonian quasi-geocentricity. A bogus history was created to make way for relativity and it worked up to recently ,once you see that there is no way to associate 'absolute space' with aether the show is over,at least as far as relativity overthrowing Newton is concerned .It turns out to be a minor mathematical squabble with little content and character. I was genuinely surprised to see what the guys here did with the information and especially as there is nothing to keep the early 20th century concepts going as working principles.In any case,you will find that the dilemma of the guys in the mid 19th century * was that Newton had left them with an astronomical framework which required no aether - "The fictitious matter which is imagined as filling the whole of space is of no use for explaining the phenomena of Nature, since the motions of the planets and comets are better explained without it, by means of gravity; and it has never yet been explained how this matter accounts for gravity. The only thing which matter of this sort could do, would be to interfere with and slow down the motions of those large celestial bodies, and weaken the order of Nature; and in the microscopic pores of bodies, it would put a stop to the vibrations of their parts which their heat and all their active force consists in. Further, since matter of this sort is not only completely useless, but would actually interfere with the operations of Nature, and [314] weaken them, there is no solid reason why we should believe in any such matter at all. Consequently, it is to be utterly rejected." Newton Optics 1704 * http://www.bodley.ox.ac.uk/cgi-bin/ilej/image1.pl?item=page&seq=9&siz... In short,if you want to waste your time by having guys bloke smoke where the sun don't shine then welcome to sci.physics !. >>Insofar as the non-inertial motions of the earth can be neglected during >>the flight time of the light, the image at the target will remain [quoted text clipped - 23 lines] >I'm sure you're right coz I know next to nothing about physics but why >doesn't the "strike point" move? Well, upon further thought, I guess the explanation could be that the motion of the source affects the angle of the "laser beam" so that it has a "sideways" component the equivalent of the 1 cm movement of the target. This would allow the laser beam to leave the laser "straight down its centre line" regardless of the movement of the laser. If this is true, this should mean that if a laser beam on a rocket ship is fired sideways so that the path of the laser beam is exactly at right angles to the path of the rocket, if the rocket increases speed by 400 km/second, the path of the laser beam will no longer be exactly at 90 degrees to the path of the rocket, and will not be parallel to the path of the laser beam before the rocket increased speed. Also, the change in velocity of the earth from 340 km/sec to 400 km/sec should mean clocks run at different speeds at different times of the year. Darkknight. > >>Insofar as the non-inertial motions of the earth can be neglected during > >>the flight time of the light, the image at the target will remain [quoted text clipped - 29 lines] > target. This would allow the laser beam to leave the laser "straight > down its centre line" regardless of the movement of the laser. Almost correct: the speed of light remains constant, so that the components don't add up vectorially. But it's even more straightforward: the light inside the laser follows a certain angle to start with (90 degrees in the rocket's rest frame, but not in the stationary frame), and the light doesn't change angle when it leaves the laser. > If this is true, this should mean that if a laser beam on a rocket > ship is fired sideways You mean relative to the rocket > that the path of the laser beam is exactly > at right angles to the path of the rocket, You mean relative to the CMBR frame I suppose... > if the rocket increases > speed by 400 km/second, the path of the laser beam will no longer be > exactly at 90 degrees to the path of the rocket, and will not be > parallel to the path of the laser beam before the rocket increased > speed. That's correct - in the CMBR frame. > Also, the change in velocity of the earth from 340 km/sec to 400 > km/sec should mean clocks run at different speeds at different times > of the year. That's correct as well - in the CMBR frame. Of course, "in" the solar frame they run (for all practical purposes) at constant speed. Harald > > >>Insofar as the non-inertial motions of the earth can be neglected during > > >>the flight time of the light, the image at the target will remain [quoted text clipped - 9 lines] > > >>surveying over just 10 meters would be off by a cm! This does not > happen. [snip] > > Well, upon further thought, I guess the explanation could be that the > > motion of the source affects the angle of the "laser beam" so that it [quoted text clipped - 7 lines] > rocket's rest frame, but not in the stationary frame), and the light doesn't > change angle when it leaves the laser. The posts above were not about the speed of light or about rockets. The scenario was a laser experiment on the surface of the Earth in which the laser is positioned perpendicular to the essentially linear movement of the solar system through the galaxy at around 40 degrees latitude and approximately 300 feet between source and target. A laser pulse is sent every hour for 24 hours and the strikes marked on the target. Since the target moves approximately four inches during the transit time of the laser beam after the pulse is fired and before it strikes the target, the plot of the strikes on the target over the 24 hour period should be an ellipse with the center representing where the laser is actually aimed. The result of the experiment is that the strikes are always in the same place instead producing the elliptical pattern. Vern > > > >>Insofar as the non-inertial motions of the earth can be neglected during > > > >>the flight time of the light, the image at the target will remain [quoted text clipped - 29 lines] > movement of the solar system through the galaxy at around 40 degrees > latitude and approximately 300 feet between source and target. You may here above replace "rocket" by "Earth", that doesn't matter for SRT. What matters is that one may choose (pretend to be) any approx. inertial frame (solar, CMBR) as "stationary" frame. Note that for MMX the Earth's surface isn't approximately an inertial frame, except for very short time intervals. > A laser > pulse is sent every hour for 24 hours and the strikes marked on the [quoted text clipped - 5 lines] > strikes are always in the same place instead producing the elliptical > pattern. I've worked out such things in the past, and it always worked out perfectly. Here you give insufficient detail, thus I don't know what you overlook - but probably you overlooked the Lorentz contraction. Harald > <vern@bealenet.com> wrote in message [snip] > > The posts above were not about the speed of light or about rockets. > > The scenario was a laser experiment on the surface of the Earth in [quoted text clipped - 21 lines] > Here you give insufficient detail, thus I don't know what you overlook - but > probably you overlooked the Lorentz contraction. Perhaps I should not have posted the subject matter is this thread as the experiment I am discussing is a simple path of light experiment that does not involve MMX concepts, SRT, length contraction, non-inertial frames or choice of frames. However, I was responding to Tom's statements in Message No. 18 which were applicable to path of light issues, so it seemed appropriate. The issue here is whether there is aberration of terrestial light. The experiment I outlined indicates that there is not, yet that contradicts accepted theory of light (there is no reason that all light is not aberrated). I have asked Tom for his explanation of why terrestial light is not aberrated in Message No. 38. What is yours? If you need more details of the experiments, a link is posted in Message No. 21 or 23. Vern > > <vern@bealenet.com> wrote in message > [quoted text clipped - 30 lines] > that does not involve MMX concepts, SRT, length contraction, > non-inertial frames or choice of frames. If you think about it, that's impossible: any path is relative to some material reference system, even if by extension. > However, I was responding to > Tom's statements in Message No. 18 which were applicable to path of [quoted text clipped - 4 lines] > asked Tom for his explanation of why terrestial light is not aberrated > in Message No. 38. What is yours? I kind of commented on that in message 31; and on earth there is no speed difference. > If you need more details of the > experiments, a link is posted in Message No. 21 or 23. Reading that, I could not spot what you consider to be a problem; however the following remark of you is revealing: "Using terrestial light sources, the experiment should have revealed the full effect of secular aberration, but instead it is consistent with a model of light which is a wave in an aether where the aether is like a bubble around the Earth and the Earth's rotation on its axis does not affect the aether. This corresponds with explanations for H-K type experiments and GPS, where an Earth-axis-centered frame is used for measurements. " That's commonly called ECI frame; as it happens, SRT is compatible with choosing that frame; it is generally used. Harald > <vern@bealenet.com> wrote in message [snip] > > Perhaps I should not have posted the subject matter is this thread as > > the experiment I am discussing is a simple path of light experiment [quoted text clipped - 3 lines] > If you think about it, that's impossible: any path is relative to some > material reference system, even if by extension. What I said was that the experiment I am discussing does not involve a consideration of choice of frames. I guess what I should have said was that it doesn't involve a transformation between frames. All considerations are in a frame of reference in which the CMBR is isotropic (the CMBR frame). > > However, I was responding to > > Tom's statements in Message No. 18 which were applicable to path of [quoted text clipped - 7 lines] > I kind of commented on that in message 31; and on earth there is no speed > difference. This is not about speed difference. It is about whether terrestial light sources have aberration. > > If you need more details of the > > experiments, a link is posted in Message No. 21 or 23. [quoted text clipped - 12 lines] > That's commonly called ECI frame; as it happens, SRT is compatible with > choosing that frame; it is generally used. We are evidently talking past each other. This has nothing to do with SRT and the frame in the experiment is the not the ECI frame, it is in the frame of the Earth's surface. The comment I made in the previous post was only an analogy to HK and GPS and aether theories which use an ECI frame. That was only relative to a positing a reason why terrestial light does not have aberration. Do you accept that terrestial light does not have aberration (in the reference frame of the Earth's surface), and if so, why do you believe there is no aberration, when all light should exibit aberration. Vern [snip] > We are evidently talking past each other. This has nothing to do with > SRT and the frame in the experiment is the not the ECI frame, it is in [quoted text clipped - 5 lines] > the Earth's surface), and if so, why do you believe there is no > aberration, when all light should exibit aberration. Sorry to have to respond to my own post, but obviously the above paragraph of Message No. 36 is in error as I was in a hurry and I have taken some time to try to think the experiment through from the standpoint of reference frames. The experiment is based on the assumption that when a laser pulse is in the air between the source and target, the target continues to move along with the Earth in the essentially linear motion of the Solar System towards the constellation Leo. The target will have moved about 4 inches before the pulse hits it. So the reference frame for the whole experiment is the CMBR frame. Does the target move in the reference frame of the Earth's surface in the time the pulse is in the air? I guess the answer is "no" because both the source and target are stationary during the length of time starting when the pulse is fired from the source and ending when the pulse hits the target in the reference frame of the Earth's surface. But that can't be used as a reason that there is no aberration of terrestial light, since in the reference frame of the CMBR, the Earth is moving and that resulting aberration of terrestial light should be evident in any experiment using light on the surface of the Earth. Vern > [snip] > [quoted text clipped - 12 lines] > taken some time to try to think the experiment through from the > standpoint of reference frames. That's great, I could have saved myself time by immediately looking at this posting of yours. > The experiment is based on the > assumption that when a laser pulse is in the air between the source and > target, the target continues to move along with the Earth in the > essentially linear motion of the Solar System towards the constellation > Leo. The target will have moved about 4 inches before the pulse hits > it. So the reference frame for the whole experiment is the CMBR frame. OK > Does the target move in the reference frame of the Earth's surface in > the time the pulse is in the air? I guess the answer is "no" because > both the source and target are stationary during the length of time > starting when the pulse is fired from the source and ending when the > pulse hits the target in the reference frame of the Earth's surface. Right - apart of a negligibly small rotation. > But that can't be used as a reason that there is no aberration of > terrestial light, since in the reference frame of the CMBR, the Earth > is moving and that resulting aberration of terrestial light should be > evident in any experiment using light on the surface of the Earth. What do you think needs to abberate, and why? What makes you think that the light should change its course when it exists the laser? (Note how the path inside the laser is when mapped to the CMBR frame). Harald > <vern@bealenet.com> wrote in message [snip] > > The experiment is based on the > > assumption that when a laser pulse is in the air between the source and [quoted text clipped - 21 lines] > light should change its course when it exists the laser? (Note how the path > inside the laser is when mapped to the CMBR frame). I think this is more of an issue and question about absolute motion. If you take as a fact that the measurements using the CMBR establish that the Earth is moving essentially linearly at approximately 370 km/s towards the constellation Leo, then a consequence of that fact is that when a laser beam is shot from a laser on the surface of the Earth to a target also on the surface of the Earth such that the laser and target are aligned perpendicularly to the direction towards Leo and the distance between the laser and the target is approximately 300 feet, then from the time the beam leaves the laser the target will have moved approximately four feet in the direction towards Leo (obviously, the laser would have moved too, but that's immaterial since what happens to the laser after the beam leaves it has no effect on where the beams goes or what happens to the target). I have made no statement about the light changing course when it exits the laser. That involves whether the movement of the source imparts momentum to the beam. Tom Roberts has already said that it does not and the beam does not leave at an angle. But that does not have a bearing on whether the target moves during the transit time of the beam. Whether the target moves or not is a statement about absolute motion. If it is accepted that the Earth is moving as stated above, then it doesn't matter that motion is not apparent if electing to use an Earth-surface reference frame. Your choice of frames does not stop the Earth from moving. Therefore, the experiment outlined above has to account for that movement in determining the outcome of the experiment. That's where aberration (or perhaps you could say a lack of aberration) comes into play. Since the movement of the Earth towards Leo does not have any effect on the beam, the beam would be expected to strike the target approximately four inches behind (opposite the direction towards Leo) where it was aimed because that's how far the target moved towards Leo in the transit time of the beam. Arguments concerning not knowing where the laser was originally aimed are negated by shooting a beam every hour over a 24 hour period. An ellipse pattern should be evident on the target with the center of the ellipse being where the laser was aimed. Vern > > <vern@bealenet.com> wrote in message > [quoted text clipped - 27 lines] > > I think this is more of an issue and question about absolute motion. That's opening the Debate Box. To avoid wasting time on that, you can simply discuss how it looks as measured in the CMBR frame, and everyone who knows SRT will agree, while you can draw your own conclusions. > If you take as a fact that the measurements using the CMBR establish "establish"? See above. > that the Earth is moving essentially linearly at approximately 370 km/s > towards the constellation Leo, then a consequence of that fact is that [quoted text clipped - 7 lines] > to the laser after the beam leaves it has no effect on where the beams > goes or what happens to the target). What matters is the light's direction inside the moving laser: that determines "where the beam goes". I have the impression that you still didn't get that. How do you think it works with a bullet in a moving rifle? > I have made no statement about > the light changing course when it exits the laser. That involves > whether the movement of the source imparts momentum to the beam. Tom > Roberts has already said that it does not and the beam does not leave > at an angle. ??? Quite to the contrary - thus my hunch was correct. Please work out how a bullet moves when you replace the laser by a rifle, and you should understand. Harald > But that does not have a bearing on whether the target > moves during the transit time of the beam. Whether the target moves or [quoted text clipped - 15 lines] > > Vern > <vern@bealenet.com> wrote in message [snip] > > I think this is more of an issue and question about absolute motion. > > That's opening the Debate Box. To avoid wasting time on that, you can simply > discuss how it looks as measured in the CMBR frame, and everyone who knows > SRT will agree, while you can draw your own conclusions. The speed of the Earth towards the constellation Leo is not fast enough to have to worry about relativistic corrections to a Galilean transformation, so I believe the experiment being discussed can be viewed within a classical physics framework. However, all your persistent about consideration of the direction of travel of the beam in the CMBR frame has paid off, I think. When I read the experiment, it bothered me that he kept stating that the target moved approx. four inches in the time the beam was in the air, so therefore the beam should have struck the target four inches behind where it was supposed to. Finally, I think you have made me realize his fundamental error. In the reference frame of the surface of the Earth, the target does not move four inches in the transit time of the beam, therefore one would expect the beam to strike the target where it is supposed to. In the frame of the CMBR, because changing frames can't change the outcome of an experiment, naturally the beam is still going to strike the target in the same place. The only way for that to happen is for the beam to appear to be travelling at an angle in that frame so that the four inches that the target moves in the transit time is accounted for. Evidently, Kehr assumed that because the measurements of the Earth's motion wrt to the CMBR establish that the Earth is moving through the cosmos at approx. 370 km/s that somehow that motion had to be accounted for in experiments on the surface of the Earth. It's kind of like, "I throw the ball straight up high enough and it won't land where I'm standing because the Earth will have moved through the cosmos X number of feet in the time it's in the air." Given that reasoning, I don't think any of the laws of physics would work. If what I am saying above is correct, then I'll have to thank you and Tom for helping me see it. If it's not then maybe you can continue to steer me in the right direction. Vern > > <vern@bealenet.com> wrote in message > [quoted text clipped - 13 lines] > considerations are in a frame of reference in which the CMBR is > isotropic (the CMBR frame). Well, then you're going straight for MMX concepts! MMX was first of all considered relative to a frame in which light was thought to be truly isotropic; length contraction was one explanation, and it led to SRT. > > > However, I was responding to > > > Tom's statements in Message No. 18 which were applicable to path of [quoted text clipped - 10 lines] > This is not about speed difference. It is about whether terrestial > light sources have aberration. Without Lorentz contraction they would have aberration, and an "absolute speed" could be determined. > > > If you need more details of the > > > experiments, a link is posted in Message No. 21 or 23. [quoted text clipped - 22 lines] > the Earth's surface), and if so, why do you believe there is no > aberration, when all light should exibit aberration. "all light should exhibit aberration" is overly vague. And it has everything to do with SRT: the main point is that all inertial frames are equally valid for descriptions of light propagation. Just describe light propagation of MMX in the CMBR frame and you'll find that, assuming Lorentz contraction, no aberration will be noticeable for observers on Earth (important detail: the mirrors are not exactly at 45 degrees angle). Cheers, Harald >> >If the light path of the laser is parallel to the direction of motion >> >(which it could be after 8 hours) then the target hasn't moved so a [quoted text clipped - 14 lines] >rocket's rest frame, but not in the stationary frame), and the light doesn't >change angle when it leaves the laser. You seem to have mixed up the two scenarios, the laser on the surface of the earth aiming at a target and the rocket ship with a laser on board, so I can't tell what you're trying to say. I realise the light doesn't change its angle "in-flight", but if it didn't keep exact pace with the laser gun, it would be at risk of striking the inside of the "laser gun" instead of going "straight down the centre line" of the laser. So for the laser on the rocket ship, the laser would have to be aimed slightly off 90 degrees to get the path of the laser beam to be at exactly 90 degrees to the path of the rocket. >>>>>>>>>> quote from my previous post <<<<<<<<<<<< Well, upon further thought, I guess the explanation could be that the motion of the source affects the angle of the "laser beam" so that it has a "sideways" component the equivalent of the 1 cm movement of the target. This would allow the laser beam to leave the laser "straight down its centre line" regardless of the movement of the laser. If this is true, this should mean that if a laser beam on a rocket ship is fired sideways so that the path of the laser beam is exactly at right angles to the path of the rocket, if the rocket increases speed by 400 km/second, the path of the laser beam will no longer be exactly at 90 degrees to the path of the rocket, and will not be parallel to the path of the laser beam before the rocket increased speed. >>>>>>>>>> end quote <<<<<<<<<<<<<<< >> If this is true, this should mean that if a laser beam on a rocket >> ship is fired sideways [quoted text clipped - 5 lines] > >You mean relative to the CMBR frame I suppose... I don't know what you mean by "relative to the CMBR frame". What I thought I meant was that the path of the laser beam and the rocket ship are at right angles in "absolute space" but I don't know if that's meaningful since determining the "path of the laser beam" is somewhat difficult in practice. Perhaps my "absolute space" is your "CMBR frame". I didn't realise you had to define a frame to measure an angle. >> if the rocket increases >> speed by 400 km/second, the path of the laser beam will no longer be [quoted text clipped - 3 lines] > >That's correct - in the CMBR frame. Wouldn't the angle between the "two laser beams" be slightly different in any frame. I guess you're telling me that if there were some means of comparing the angle of the laser beam on the rocket ship itself before and after the speed change, no change in angle would be seen - hmmm, yep, I was thinking of absolute space, not counting the expansion of space itself. >> Also, the change in velocity of the earth from 340 km/sec to 400 >> km/sec should mean clocks run at different speeds at different times >> of the year. > >That's correct as well - in the CMBR frame. Of course, "in" the solar frame >they run (for all practical purposes) at constant speed. I was thinking that the daily rotation of the earth would take a slightly different time at different times of the year (assuming it wasn't slowing down at all) - but perhaps the rotation speed of the earth and all events on it also change by the same amount, in the CMBR frame, so the net effect is zero and there's no way to tell that it's happening. Thanks for your reply. Darkknight >>> >If the light path of the laser is parallel to the direction of motion >>> >(which it could be after 8 hours) then the target hasn't moved so a [quoted text clipped - 26 lines] >path of the laser beam to be at exactly 90 degrees to the path of the >rocket. "Don't add up vectorially". Hmmm. Now I see what you mean. The change in the velocity of the rocket causes the angle/ "flight path" of the laser beam to change so that it still goes down the centre line of the laser, rather than the laser beam "keeping pace with the rocket". I wonder why the change in angle exactly matches the change in speed - a happy coincidence of nature. (I wonder if Michelson/Morley knew this). Darkknight. > >>> >If the light path of the laser is parallel to the direction of motion > >>> >(which it could be after 8 hours) then the target hasn't moved so a [quoted text clipped - 34 lines] > in speed - a happy coincidence of nature. (I wonder if > Michelson/Morley knew this). The light in the laser follows the laser geometry, by necessity. M&M didn't have lasers at that time, and some papers were written later about possible effects of angle changes from mirrors. It was shown that such effects can't explain the null result. Of course, everything works out taking into account Lorentz contraction. Harald > >> >If the light path of the laser is parallel to the direction of motion > >> >(which it could be after 8 hours) then the target hasn't moved so a [quoted text clipped - 18 lines] > of the earth aiming at a target and the rocket ship with a laser on > board, so I can't tell what you're trying to say. I didn't see two scenario's but what I wrote there is valid in general, thus for all scenarios. > I realise the light doesn't change its angle "in-flight", but if it > didn't keep exact pace with the laser gun, it would be at risk of [quoted text clipped - 21 lines] > > >>>>>>>>>> end quote <<<<<<<<<<<<<<< Why do you quote again what I quoted already? Now your quotes are double... > >> If this is true, this should mean that if a laser beam on a rocket > >> ship is fired sideways [quoted text clipped - 7 lines] > > I don't know what you mean by "relative to the CMBR frame". I referred to your earlier post as apparently you were referring to it: ">> the motion of the Earth at >> approximately 370 kilometers per second linearly towards the >> constellation Leo, as evidenced by the CMBR" > What I thought I meant was that the path of the laser beam and the > rocket ship are at right angles in "absolute space" but I don't know > if that's meaningful since determining the "path of the laser beam" is > somewhat difficult in practice. Perhaps my "absolute space" is your > "CMBR frame". I didn't realise you had to define a frame to measure > an angle. Yes you have to - it's even crucial for understanding. > >> if the rocket increases > >> speed by 400 km/second, the path of the laser beam will no longer be [quoted text clipped - 24 lines] > frame, so the net effect is zero and there's no way to tell that it's > happening. Indeed, all effects compensate each other - that's the essence of the Lorentz transformations. > Thanks for your reply. You're welcome. Harald > >>Insofar as the non-inertial motions of the earth can be neglected during > >>the flight time of the light, the image at the target will remain [quoted text clipped - 43 lines] > > Darkknight. You seem like a genuine guy but you will never get it,the original Roemerian insight on finite light speed on appearance was mixed together with Keplerian orbital geometry in a complex way by Newton. Nobody really cares what Newton did even though it is the work of a guy who could bend information to suit his purpose without the slightest trace of remorse for the destruction caused to the work of Copernicus,Kepler and Roemer.I can spare you an existence built on empty working principles and direct you towards what Newton actually did and why it is now important to restore the original productive working principles but I sup[pose you want to remain sounding profound without actually being so. For an astronomer,an intuitive astronomer as I am,the following passage by Newton is remarkable for the asmount of astronomical principles he breaks within a single paragraph.Pity you do not have the highest human intutive faculty to recognise this incredible feat of intellectual and intutive vandalism, a sort of anti-genius - PHENOMENON V. "Then the primary planets, by radii drawn to the earth, describe areas no wise proportional to the times; but that the areas which they describe by radii drawn to the sun are proportional to the times of description. For to the earth they appear sometimes direct, sometimes stationary, nay, and sometimes retrograde. But from the sun they are always seen direct, and to proceed with a motion nearly uniform, that is to say, a little swifter in the perihelion and a little slower in the aphelion distances, so as to maintain an equality in the description of the areas. This a noted proposition among astronomers, and particularly demonstrable in Jupiter, from the eclipses of his satellites; by the help of which eclipses, as we have said, the heliocentric longitudes of that planet, and its distances from the sun, are determined." NEWTON >> In the frame of the earth surface at the location of the laser, the >> light leaves the laser straight down its centerline. > > Then why do telescopes have to be "tilted" to account for stellar > aberration? i.e. the line of the telescope has to be at a very slight > angle to the line of the light. Because the telescope only sees light that travels down its centerline, and in the locally-inertial frame of the telescope the light does not travel directly along the line connecting source and telescope (locations simultaneous in that frame). That _is_ what aberration is. >> [a laser and target rigidly mounted to the surface of the earth] >> Insofar as the non-inertial motions of the earth can be neglected [quoted text clipped - 17 lines] > target has moved by (1/300000) * 400 km - which is .001333 km - > equals 130 cm. (or 1cm over 10 meters as you say). You are assuming that light only travels at c relative to the CMBR dipole=0 frame. This is not so -- observations show that light travels isotropically with speed c in any inertial frame the earth's surface inhabits (and well-tested theories extend this to all inertial frames). Consider the instantaneously-comoving inertial frame of the laser at the instant a short pulse is emitted. During the travel time of the light pulse the target will move relative to that frame due to the noninertial motions of the earth. If those noninertial motions are smaller than the resolution of measuring the image position at the target, the image at the target will be measured to remain motionless. For a 10 meter path laser-to-target, light takes ~33 ns to travel between them. For the ~500 m/s rotation of the earth, the total motion of the target is ~16 microns, but the non-inertial component of that rotation is 10m/Rearth to first order, and is thus unmeasurable. For the ~30 km/s orbital speed of the earth, the total motion is ~1 mm, but the non-inertial component of that rotation is 10m/Rorbit to first order, and is thus unmeasurable. For the 300 km/s motion relative to the CMBR dipole=0 frame, there is no known non-inertial component (if there is, it is most likely something like 10m/Rgalaxy...). Note that variations in the optical properties of the air will be _far_ larger than these values. > I'm sure you're right coz I know next to nothing about physics but why > doesn't the "strike point" move? It does, but only by amounts so much smaller than measurement resolutions that it is unobservable. Tom Roberts tjroberts@lucent.com > >> In the frame of the earth surface at the location of the laser, the > >> light leaves the laser straight down its centerline. [quoted text clipped - 7 lines] >travel directly along the line connecting source and telescope >(locations simultaneous in that frame). That _is_ what aberration is. ok, well after making the above statement, I subsequently learnt from Harry that angles are relative to a frame, so I was thinking of absolute space (which could be called the CMBR frame), rather than the earth's inertial frame, when I made the above statement, so when David Smith told me the telescope was not tilted relative to the line of the light I got even more lost (I guess he was talking about the earth's inertial frame). So now my understanding is this 1. In the CMBR frame, the telescope is at an angle to the line of the light (which is what I meant when I said it was tilted). 2. In the earth's frame, I guess the telescope and the light are parallel (because you said "the telescope only sees light that travels down its centerline") I find number 2 confusing because I keep thinking the telescope is moving so the light will collide with the inside of the telescope, then I remind myself the "parallel-ness" of the light and the telescope is an illusion in the earth's frame. > >> [a laser and target rigidly mounted to the surface of the earth] > >> Insofar as the non-inertial motions of the earth can be neglected [quoted text clipped - 22 lines] >isotropically with speed c in any inertial frame the earth's surface >inhabits (and well-tested theories extend this to all inertial frames). I'm lost as to how you can draw the conclusion that I thought the speed of light was c only in the CMBR frame. I'm happy to accept that it is c in all frames (but I want to learn more about it). However I've since learned (from Harry) that a change in speed of the laser source affects the angle of the laser beam (relative to the CMBR frame, say) so the laser always hits the target in the same spot, even though the distance the target moves during the travel time of the light, varies with the change in speed of the earth relative to the CMBR frame. >Consider the instantaneously-comoving inertial frame of the laser at the >instant a short pulse is emitted. During the travel time of the light [quoted text clipped - 21 lines] >It does, but only by amounts so much smaller than measurement >resolutions that it is unobservable. I'm not sure I understand but I'm thinking that what you're saying is that because the speed of the earth is changing all the time, including during the travel time of the laser beam, this makes it a non-inertial frame - so the target is moving at a very slightly (and unmeasurably) different speed when the laser photon hits it, than it was when the photon left the laser. Ok, I didn't even think of that. Thanks! (a lot). Darkknight > > I believe this is an important issue and one that I have been > > considering in relation to the laser experiments done by H. Webster [quoted text clipped - 21 lines] > notice if light danced around by that milliradian as the earth turned: > surveying over just 10 meters would be off by a cm! This does not happen. Yes, but according to your statement that the speed of the source laser (anywhere from 340 to 400 km/s, depending on orientation) does not affect the path of the beam, there should be that "dancing around" as you put it, because the target does move in the time it takes the laser to reach it. How do you account for the fact that "This does not happen." Vern >> That 370 km/s is roughly 0.001 times the speed of light, and the >> angle [quoted text clipped - 12 lines] > to reach it. How do you account for the fact that "This does not > happen." I just posted a response to darkknight that estimates how large the "dancing" actually is for that 10 m path. Values are completely unobservable. As surveyors around the world regularly observe. I of course used SR in those estimates, not his model in which the CMBR dipole=0 frame is special. > An ellipse pattern should be evident on the > target with the center of the ellipse being where the laser was aimed. Yes. But for the above 10 meter path, the size of that ellipse is less than an Angstrom, and is completely unobservable. Tom Roberts tjroberts@lucent.com > > Tom Roberts wrote: > >> That 370 km/s is roughly 0.001 times the speed of light, and the [quoted text clipped - 17 lines] > "dancing" actually is for that 10 m path. Values are completely > unobservable. As surveyors around the world regularly observe. I believe you based your estimate on the non-inertial component, which was not considered in the experiment because the value (as you show) is not significant. In Message No. 41 to Harry I outline what I see as the experimenter's error. He assumed that because it is established by the CMBR that the Earth is moving essentially linearly (in the time it takes for a laser beam to reach a target 300 feet away) through the Cosmos at approx. 370 km/s that that motion must be considered in any experiment on the Earth's surface. In other words, he assumed that in the transit time between the laser beam being fired and striking the target, the target would have moved approx. four inches. Apparently, he didn't realize that that's only true in the CMBR frame, not in the frame of the Earth's surface, as there is no relative motion between the laser and the target in the frame of the Earth's surface. Therefore, it appears that the whole basis for his assumption that plotting strikes every hour would result in an elliptical pattern is flawed. In the frame of the CMBR, however, the target would move approx. four inches in the transit time of the beam and an observer in that frame, I guess, would notice that the beam would seem to take an angled path to "catch up" to the target. If the above analysis is wrong, I hope you'll correct me. Vern >> Take a friend and a couple of megaphones out to a field on a windy day. >> Use your megaphone to shout to your friend while he uses his to [quoted text clipped - 28 lines] > >Tom Roberts tjroberts@lucent.com The MMX experiment is analyzed over and over with no conclusion, and the fact that it was the MMX that provoked relativity should make it easy or even mandagtroy to use relativity to explain it, but relativity is never used! Let me explain. In general relativity there is propounded a space defined by (ict x y z). It's a hyperbolic space. Using this set you can solve the MMX null problem right away. How? Draw a capital T as a vector diagram. The upleg is c. The right branch is +V. The left branch is -V. The vector sum is the same for upstream or downstream. The designation ict means that c is at right angles to any velocity you can think of. And to sum c and V you must use the T-diagram. You can see there never would be a difference in path lengths or times. You might object that no one uses ict. That's true. Here's why: They got cute and decreed that time was just the same as any of xyz, a sort of unisex monstrosity. (This is the only way you can have a totally bogus "space-time continuum"). The wanted to use (ct x y z). They did this by algebraically impossible step of making the "metric tensor" have the "signature" -1 1 1 1 , meaning those were the elements of the diagonal. But such a matrix cannot be a tensor for a number of reasons but you will appreciate that if I pass (ct x y z) through it once I get (-ict x y z) and if I do it again I get (ct x y z) back again. You can read about it in MTWheeler's Gravitation, the telephone book bible of relativity. There doesn't seem to be one scintilla or guilt or even awareness of thes monstrosity. John Polasek http://www.dualspace.net > The MMX experiment is analyzed over and over with no conclusion, and > the fact that it was the MMX that provoked relativity should make it > easy or even mandagtroy to use relativity to explain it, but > relativity is never used! The SR explanation of the MMX result is simple: The center of the apparatus is at rest on the surface of the earth, and to sufficient accuracy it can be considered to be at rest in an inertial frame[#]. Also to sufficient accuracy the rotation of the interferometer can be ignored[#], and it can be considered to have a series of definite orientations. [#] Non-inertial motions during the transit time of the light are quite small, and to first order are parallel to the mirrors. Motions parallel to mirrors have no effect on the reflected light. Higher-order effects due to these rotations are completely negligible. In the inertial frame of the interferometer, the speed of light is isotropically c, so the position of the fringes does not depend on the orientation of the interferometer. Hence a null result is expected, which is fully consistent with their measurement. BTW the MMX did not really "provoke" relativity. In later years, Einstein stated he did not remember if he was aware of it in 1905 or not. But he _definitely_ knew of several other experiments that refuted the simple aether theories. And the MMX was the most definitive of the early experiments. > [... bogus posturing omitted] Tom Roberts tjroberts@lucent.com > > The MMX experiment is analyzed over and over with no conclusion, and > > the fact that it was the MMX that provoked relativity should make it [quoted text clipped - 19 lines] >orientation of the interferometer. Hence a null result is expected, >which is fully consistent with their measurement. Tautologically so! Even I can see if the speed of light is isotropically c, then, yes, that's what it is, c, and we can expect no fringes. Your standards for a proof are not as high as mine. >BTW the MMX did not really "provoke" relativity. In later years, >Einstein stated he did not remember if he was aware of it in 1905 or [quoted text clipped - 5 lines] > >Tom Roberts tjroberts@lucent.com I'll restore what you label as "bogus posturing". It is more important than your fatuous and insipid explanation of the MMX above. In Misner Thorne Wheeler Gravitation pg 51 they were glad to get rid of ict in favor of ct by pushing it through the "metric" matrix that will never be a tensor. And the trick only works as a scalar product XGX'. By rights, it has to pass the simple transformation XG = (ct x y z)--> (-ct x y z) which is so wrong, that it is obvious they have suborned G in order to join what cannot be joined, time and space. This is grave algebraic malfeasance even on a sophomore level. It covers up what was known before, that with ict, time and space can never mix, like water and oil. Time is separate entirely. And it turns out that all of relativity can be deduced (only correctly) in a Euclidean space. My T-diagram is an example that immediately disposes of the MMX difficulty without dreary references to inertial frames and the hypothesis that "the speed of light is isotropically c". What is there that makes c constant? And how about Shapiro. Does relativity allow variations in c or is it all taken up in time dilation? Of course there's no ether, but there's something better. I brought this up before, but you did not comment. John Polasek http://www.dualspace.net > > The MMX experiment is analyzed over and over with no conclusion, and > > the fact that it was the MMX that provoked relativity should make it [quoted text clipped - 29 lines] > >Tom Roberts tjroberts@lucent.com Tautologically so! Even I can see if the speed of light is isotropically c, then, yes, that's what it is, c, and we can expect no fringes. Your standards for a proof are not as high as mine. >BTW the MMX did not really "provoke" relativity. In later years, >Einstein stated he did not remember if he was aware of it in 1905 or [quoted text clipped - 5 lines] > >Tom Roberts tjroberts@lucent.com (This message was lost somewhere so I repeat) I'll restore what you label as "bogus posturing". It is more important than your fatuous and insipid explanation of the MMX above. In Misner Thorne Wheeler Gravitation pg 51 they were glad to get rid of ict in favor of ct by pushing it through the "metric" matrix that will never be a tensor. And the trick only works as a scalar product XGX'. By rights, it has to pass the simple transformation XG = (ct x y z)--> (-ct x y z) which is so wrong, that it is obvious they have suborned G in order to join what cannot be joined, time and space. This is grave algebraic malfeasance even on a sophomore level. It covers up what was known before, that with ict, time and space can never mix, like water and oil. Time is separate entirely. And it turns out that all of relativity can be deduced (only correctly) in a Euclidean space. My T-diagram is an example that immediately disposes of the MMX difficulty without dreary references to inertial frames and the hypothesis that "the speed of light is isotropically c". What is there that makes c constant? And how about Shapiro. Does relativity allow variations in c or is it all taken up in time dilation? Of course there's no ether, but there's something better. I brought this up before, but you did not comment. John Polasek | > > The MMX experiment is analyzed over and over with no conclusion, Nonsense. There is a simple conclusion. That Humpty Roberts doesn't accept it is his problem. http://www.androcles01.pwp.blueyonder.co.uk/Smart/MMXwind.gif Androcles. and | > > the fact that it was the MMX that provoked relativity should make it | > > easy or even mandagtroy to use relativity to explain it, but [quoted text clipped - 69 lines] | I brought this up before, but you did not comment. | John Polasek >> In the inertial frame of the interferometer, the speed of light is >> isotropically c, so the position of the fringes does not depend on the >> orientation of the interferometer. Hence a null result is expected, >> which is fully consistent with their measurement. > Tautologically so! Even I can see if the speed of light is > isotropically c, then, yes, that's what it is, c, and we can expect no > fringes. You mean no fringe shift, of course. But this is not "tautology", this is a conclusion. > Your standards for a proof are not as high as mine. This is physics, and no "proof" is possible. The best that can happen is the theory makes a prediction that is confirmed by the experiment. And that happens here. Tom Roberts tjroberts@lucent.com > > Take a friend and a couple of megaphones out to a field on a windy day. > > Use your megaphone to shout to your friend while he uses his to [quoted text clipped - 7 lines] > such a wind your friend would not hear you (or even be able to hold a > megaphone).... If the two observers are the length of a football field apart that 5 degrees equals about 30 feet. You wouldn't even need the megaphones to detect that shift, if it existed. With the megaphones you could be more accurate at a lower wind speed. If they don't do the trick get a reflector dish like they use for microphones at football games. They also make speakers with a beam width of 10 degrees as shown here. http://www.meyersound.com/products/industrialseries/sb-1/ They make narrower beams if you need one. > Theoretically for this case and transverse wind, you (the speaker) must > point upwind by arcsin(windspeed/soundspeed); your friend (the receiver) > must point directly at the speaker, not upwind or downwind. This is also > the case for launching a motorboat across a river -- it must be > aimed/steered upriver to arrive transversely at a point opposite from > its starting point. A motorboat aimed up stream to follow a path straight across a river is continually expending energy to fight the current. A sound wave has no energy added after leaving its source, so your annalogy falls apart. At least you came closer than the more common idea that the receiver needs to aim down wind because the sound is coming from where it was carried off to. That mistake is more common when the observers are said to be moving through stationary air. BTW, the effect here is the same whether wind is blowing past stationary observers or observers are moving through stationary air. The other common mistake is to aim the receiver up wind to catch the sound blowing back like a ball thrown up wind. Fact is, sound is the transfer of momentum from one particle to the next. The megaphone has momentum relative to the moving air and will impart that momentum to the wave without aiming it up wind. Think about it, LET treats light as a wave in a medium and does not require you to aim a flashlight up wind. Sound is no different in this respect. > With light, we find no evidence of any motion that must be compensated > for, and a directional source always points directly at the receiver, [quoted text clipped - 7 lines] > those that happen to be experimentally indistinguishable from SR. By > literally hundreds of different experiments [see the FAQ for references]. Sure, there were many flawed aether theories. As you have mentiond though, there are some that are in agreement with SR. Bruce Richmond > "easy", no. But it has been done, for all known aether theories except > those that happen to be experimentally indistinguishable from SR. By > literally hundreds of different experiments [see the FAQ for references]. Tom, There is no aether theory that is "experimentally indistiguishable" from SR. The closest one is GGT (see the 1988 Gagnon paper on your own website) and the Gagnon paper shows a way of separating GGT from SR. CM Will has a 1992 paper that explains very well that it takes additional ad-hoc assumptions in order to make modern aether theories "indistinguishable" from SR. So why propapgate this myth? Just because John Baez wrote this on his website? > > "easy", no. But it has been done, for all known aether theories except > > those that happen to be experimentally indistinguishable from SR. By [quoted text clipped - 9 lines] > "indistinguishable" from SR. So why propapgate this myth? Just because > John Baez wrote this on his website? Ddda1, I assume that you don't know that Einstein had his own peculiar ether theory. Apart of that, why do *you* propagate the myth that Lorentz, Langevin etc. were mistaken when they taught SRT? What calculation errors did they make? Over the years we've seen many such claims that were all debunked. The only such claim that sofar hasn't been debunked is by Bilge, simply because he didn't (couldn't?) back it up with a concrete, real-world example by which we could put his claim to the test. Harald Harrry Looks like you are building a strawman and beating it to death. Looks like you are not addressing my question. Anyways, my question is for Tom and not for you. > Harrry > > Looks like you are building a strawman and beating it to death. Looks > like you are not addressing my question. Anyways, my question is for > Tom and not for you. Dda, since you refused to answer my simple question to you, I have to conclude that the strawman is all yours... > > Harrry > > [quoted text clipped - 4 lines] > Dda, since you refused to answer my simple question to you, I have to > conclude that the strawman is all yours... I answered to Tom Roberts. I am not interested in any discussion with you >> "easy", no. But it has been done, for all known aether theories >> except [quoted text clipped - 4 lines] > There is no aether theory that is "experimentally indistiguishable" > from SR. That is plain and simply not true. There is an infinite class of such theories, characterized by the properties: A) there is a unique inertial frame in which the one-way speed of light is isotropically c, called the "ether frame". B) Frames in motion relative to the ether frame have an anisotropic one-way speed of light, but the round-trip speed of light is isotropically c in every such frame. (The details of the anisotropy in B differs for different theories of this class; one unique member has isotropic one-way speed in every moving frame, and it is known as LET.) Those conditions define the infinite class of theories (adding a few basic postulates like the meaning of "inertial frame", definitions of clocks and rulers, etc.). They are all experimentally indistinguishable from SR because in any given frame S the only difference between their transform ether->S and SR's Lorentz transform between the same frames is in the synchronization of clocks -- clock synchronization is an arbitrary human choice and can have no effects on any physical phenomena (just on descriptions of phenomena). For instance, in any moving frame, using any one of these theories, slow clock transport behaves identically to SR's coordinate clocks in that frame, not the coordiante clocks of any other of the theories. I discussed this at length in this newsgroup in 1999 and 2001: http://groups.google.com/group/sci.physics.relativity/msg/15ceaad17bef0b6b (and refs [2] and [3] in it) > The closest one is GGT (see the 1988 Gagnon paper on your own > website) and the Gagnon paper shows a way of separating GGT from SR. I don't recall the details of that paper. But the "closest" one is LET -- it assumes that there is a unique ether frame, and also assumes that the transform to a moving frame is the Lorentz transform. Not only is LET experimentally indistinguishable from SR, it is also mathematically equivalent to SR in that they share the same set of theorems. The only differences between SR and LET are in the choice of postulates and the interpretation of some symbols, neither of which can possibly affect the theoretical prediction for any measurement (the differences are so trivial that some people consider them to be the same theory; I don't). > CM Will has a 1992 paper that explains very well that it takes > additional ad-hoc assumptions in order to make modern aether theories > "indistinguishable" from SR. I don't recall the details of that paper, either. But (A) and (B) above are pretty much "ad hoc". > So why propapgate this myth? Just because > John Baez wrote this on his website? John Baez did not write that, I did (assuming you are thinking of the FAQ page I wrote, which does indeed mention this). Look at the author of the webpage, not the URL. To date nobody has found an error in this, and I give long odds nobody ever will (this is pure math applied to physical theories). Tom Roberts > > Tom Roberts wrote: > >> "easy", no. But it has been done, for all known aether theories [quoted text clipped - 37 lines] > > I don't recall the details of that paper. Well, that's too bad. I know everything that you state above, this is the standard fare for the Mansouri-Sexl test theory, I have seen it multiple times. Unfortunately it is refuted by : -several experiments (pleading ignorance on Gagnon is not an answer, sorry. You should refamiliarize yourself with the paper. There are several more one-way light isotropy measurement papers that use GGT as a "foil" in terms of demonstrating non-equivalence between GGT and SR). See a partial list here: [url]http://prola.aps.org/abstract/PRA/v38/i4/p1767_1[/url] [url]http://prola.aps.org/abstract/PRD/v42/i2/p731_1?qid=6c4ab66eee46e0e8&qseq=4&show =30[/url] [url]http://prola.aps.org/abstract/PRD/v45/i2/p403_1?qid=630b0f834f891ba4&qseq=20&sho w=10[/url] [url]http://prola.aps.org/abstract/PRA/v34/i3/p1708_1[/url] [url]http://www.arxiv.org/PS_cache/physics/pdf/0508/0508097.pdf[/url] -a newer paper that refutes the above argument (which really belongs to Selleri) .This paper also explains why the above position is wrong. See here: http://arxiv.org/PS_cache/gr-qc/pdf/0409/0409105.pdf > But the "closest" one is LET -- it assumes that there is a unique ether > frame, and also assumes that the transform to a moving frame is the [quoted text clipped - 12 lines] > I don't recall the details of that paper, either. But (A) and (B) above > are pretty much "ad hoc". Sorry, this wouldn't do. You should really read Will's paper. I gave you the link to it above. > > So why propapgate this myth? Just because > > John Baez wrote this on his website? [quoted text clipped - 4 lines] > I give long odds nobody ever will (this is pure math applied to physical > theories). Ok, this is the page, it is your writing . There appears to be a clear contradiction between what you wrote and the papers listed above. I.e. there are ways of distinguishing GGT (and MS) from SR. The experiments are quite explicit. > Tom Roberts >> [about theories equivalent to SR] > [quoted text clipped - 4 lines] > > -several experiments (pleading ignorance on Gagnon is not an answer, I looked at it. It uses the Tangherlini transform, which is a member of the class of theories that are experimentally indistinguishable from SR. > [url]http://prola.aps.org/abstract/PRA/v38/i4/p1767_1[/url] That is Gagnon e al's paper. > [url]http://prola.aps.org/abstract/PRD/v42/i2/p731_1?qid=6c4ab66eee46e0e8&qseq=4&show =30[/url] That is Krisher et al, whose result is not in conflict with SR, or any of the theories in that class of theories I mentioned earlier. > [url]http://prola.aps.org/abstract/PRD/v45/i2/p403_1?qid=630b0f834f891ba4&qseq=20&sho w=10[/url] That is Will's 1992 paper, and in the abstract he says "It is shown that, when properly expressed in terms of measurable quantities, the results of such experiments are independent of the method of global synchronization of clocks." Now among all the theories in the above class, the only difference is in the way coordinate clocks are globally synchronized. So he comes to the same conclusion I stated above. > [url]http://prola.aps.org/abstract/PRA/v34/i3/p1708_1[/url] That's a paper by Spavieri I have not seen before, but he makes clearly false claims in his abstract -- the Tangherlini transform is _not_ distinguishable from SR. C.f. Will's abstract above. I have not looked at it, but it is dead-bang certain he made a mistake somewhere. > [url]http://www.arxiv.org/PS_cache/physics/pdf/0508/0508097.pdf[/url] > -a newer paper that refutes the above argument (which really belongs to > Selleri) .This paper also explains why the above position is wrong. I have not looked at this paper by Herrmann et al. But if by "the above argument" you mean that of Spavieri (and/or Selleri, who I know has advocated the Tangherlini transform) then I am not surprised they demolish it. > http://arxiv.org/PS_cache/gr-qc/pdf/0409/0409105.pdf That's another one I have not seen. BTW this way of specifying URLs is _MUCH_ easier to deal with that your funky [url]...[/url] -- I must manually edit those silly flags out, while this one is an active link and I just click on it >> > CM Will has a 1992 paper that explains very well that it takes >> > additional ad-hoc assumptions in order to make modern aether theories [quoted text clipped - 5 lines] > Sorry, this wouldn't do. You should really read Will's paper. I gave > you the link to it above. My memory is not perfect, and my time is not infinite. <shrug> > Ok, this is the page, it is your writing . There appears to be a clear > contradiction between what you wrote and the papers listed above. I.e. > there are ways of distinguishing GGT (and MS) from SR. Gagnon et al are wrong about distinguishing the Tangherlini transforms from SR. > The experiments > are quite explicit. Perhaps. But at least some of their claims are wrong. Tom Roberts > >> [about theories equivalent to SR] > > [quoted text clipped - 76 lines] > > Tom Roberts Tom, Do you realize that you simply declared at least a couple these papers wrong without providing any argument? These are all papers published in Phys. Rev. With all due respect to you, you are simply restating the position on your webpage. Does it cross your mind that there are a few more modern (2005) OWLS experiments that contradict your statements? Have you published your views in any of the peer reviewed journals? Have you noticed that CM Will states TWICE in his paper that MS test theories can be "made indistinguishable" by "adding ad-hoc assumptions " (and he names them) that "may or may not be correct". ? Your argument doesn't sound very good. You might want to reconsider, please re-read the Achim Peters paper and the CM Will one . I will get back to this group with a few more OWLS experiments from 2005. Now, if you say that what you are really saying on your webpage is that LET is indistinguishable from SR, then we can all pack and go home. LET is nothing but SR as explained by Jerry, so it is like saying that SR is indistinguishable from SR. > 2. Despite points 1 and 2, there is a class of nuts that insist that > reenacting MMX in a medium with n>>1 can detect the Earth motion. [quoted text clipped - 5 lines] > its glaring errors. > Both papers are patently wrong. Can you find the errors? Hmmm. Consoli has authored several papers with glaring errors, including one which purported to analyze the errors of both the MMX and Miller's experiments; amazingly, they completely ignored the large drift of the interferometer. An elementary error analysis shows that for both experiments the variations seen are not statistically significant. That is, just compute the sigma of the histogram of the readings that were averaged to obtain the final points. Even if one dreams the readings are independent (so one divides by sqrt(N)), the errorbars are larger than the variations. But the data are dominated by the systematic drift of the instrument, so that division is not warranted. Cahill has constructed an elaborate house of cards that is about to come crashing down. As have a number of other people.... I am about to put a paper onto the preprint servers that completely explains Miller's anomalous result: 1) his result is not statistically significant (errorbars are much larger than the variations in his data) 2) his analysis technique (shared with MMX and all contemporary experiments) is seriously flawed, and _forces_ the noise that is present to _look_ like a "signal" (i.e. an approximate sinusoid with period 1/2 turn). The basic problems are in averaging the data and assuming the systematic error is linear; the larger problem is the lack of a quantitative error analysis. 3) a new analysis of Miller's data uses a quantitative model of his systematic error that accounts for 100% of his usable data, leaving no signal at all, with errorbars of 0.015 fringe -- considerably smaller than the false signal he found. 4) Miller himself could not have known about this, due to the limitations of his time. Modern authors have no such excuse. This paper will seriously embarrass anyone who ever published a paper extolling Miller's result. I have a complete second draft, but am giving a colloquium tomorrow (on a related subject), and I won't have time to put it online until after that. Tom Roberts > > 2. Despite points 1 and 2, there is a class of nuts that insist that > > reenacting MMX in a medium with n>>1 can detect the Earth motion. [quoted text clipped - 45 lines] > > Tom Roberts Excellent, witing for your paper. BTW, your website is still not corrected (clarified) as per our interaction in this thread. The funny thing is that both Cahill and Consoli prove through the respective papers that they cannot construct elementary equations. Both of them have conceptual errors in setting up the explanation of their experiments. Thirs are not numerical analysis errors, they are errors caused by their antirelativistic bias. > [to me] > witing for your paper. Unfortunately an administrative delay has arisen, and it will probably be several weeks before I can put it up on the preprint servers. Basically I am starting a new job and need the ink to dry on the new appointment before I can upload using the affiliation I want to use (I want to maximize the chance it will get accepted by Rev. Mod. Phys.). > BTW, your website is still not corrected (clarified) as per our > interaction in this thread. I have not updated that old page since 2000. I hope to get around to an update sometime soon, basically because I reference it in that paper. > The funny thing is that both Cahill and Consoli prove through the > respective papers that they cannot construct elementary equations. Both > of them have conceptual errors in setting up the explanation of their > experiments. Thirs are not numerical analysis errors, they are errors > caused by their antirelativistic bias. Yes. In my experience such "antirelativistic bias" seems to only afflict people who do not actually understand SR. The other interesting thing is: now that I understand Miller's results, _each_and_every_ experiment claimed to refute SR around here has no stature to do that. Either because it is not statistically significant, because the experimenter made clear and obvious errors, or because it simply is not reproducible. In most cases the people claiming that "SR is refuted" do not understand how science is done, today. It is also rather amusing that so many of these anomalous experiments claim agreement with Miller's results, which are quite clearly completely bogus. Tom Roberts > > [to me] > > waiting for your paper. [quoted text clipped - 4 lines] > appointment before I can upload using the affiliation I want to use (I > want to maximize the chance it will get accepted by Rev. Mod. Phys.). Congratulations! > > BTW, your website is still not corrected (clarified) as per our > > interaction in this thread. > > I have not updated that old page since 2000. I hope to get around to an > update sometime soon, basically because I reference it in that paper. Good, this will also clear a lot of confusion, lots of people cite from your page. > > The funny thing is that both Cahill and Consoli prove through the > > respective papers that they cannot construct elementary equations. Both [quoted text clipped - 4 lines] > Yes. In my experience such "antirelativistic bias" seems to only afflict > people who do not actually understand SR. Well, I just "caught" a new one: I tried to send the Editor in Chief of Progress in Physics a note about the errors in Cahill's paper. The answer was a barrage of stories about the validity of Cahill's experiment (he didn't do any), anbout the agreement with DeWitte's observations, etc. It turns out that, if you look at what Progress in Physics publishes, they are at par with another privately funded antirelativistic "journals" : Apeiron. Both are havens for kooks. > The other interesting thing is: now that I understand Miller's results, > _each_and_every_ experiment claimed to refute SR around here has no [quoted text clipped - 6 lines] > claim agreement with Miller's results, which are quite clearly > completely bogus. At least Miller was honest. Cahill, Consoli and many like them are not. > Tom Roberts > [...]about the agreement with DeWitte's > observations, etc. [...] When DeWitte first started discussing his experiment around here, I though "Wow! he really has something", and I communicated with him, suggesting we collaborate. He sent me his "data", and a long diatribe he was outraged that Phys. Rev. Lett. had rejected (it contained zillions of elementary errors, and exceeded their page limit by a factor of 5 or so -- DeWitte simply did not have a clue). I learned he had serious emotional/mental problems, and his "data" were just a few graphs (i.e. no actual table of readings -- he got fired and no longer had access to it). But from his plot an estimate of his errorbar can be made, and it exceeds the difference solar-sidereal day. As I keep saying: Amateurs look for patterns, professionals look at errorbars. > At least Miller was honest. Miller was honest and competent. I admire him -- he _really_ stuck to his guns and made every effort he could to ensure his result was correct. But like us all, he was a prisoner of his time. Because of the accumulation of knowledge since then, and the ubiquity of digital computers, I can show how he was fooled and that his data have no real signal at all. > Cahill, Consoli and many like them are not. I don't know if its truly dishonesty, or merely self-delusion. As far as science goes, it does not matter, of course. Tom Roberts > > [to me] > > witing for your paper. [quoted text clipped - 12 lines] > claim agreement with Miller's results, which are quite clearly > completely bogus. Looking forward to your paper Tom! Keep up the good work - shevek | Perhaps. But at least some of their claims are wrong. | | Tom Roberts "Yes, tests of strong fields are few and far between, but there are some: the binary pulsars, and observations of accretion disks near black holes" -- Tom Roberts "I am not an astronomer" -- Tom Roberts. Humpty Roberts let out a great sigh. " <sigh>", he said. "The nuances of English. I was discussing the usage of words and not the concepts they represent." -- Tom Humpty Roberts tjroberts@lucent.com news:ZDmYf.51582$2O6.5573@newssvr12.news.prodigy.com "real" has nothing to do with it. -- Humpty Roberts Is it a) "But the ray moves relatively to the initial point of k, when measured in the stationary system, with the velocity c-v..." or b) "It follows, further, that the velocity of light c cannot be altered by composition with a velocity less than that of light. For this case we obtain V = (c+w)/(1+w/c) = c." "Is it [... irrelevant verbiage]" -- Humpty Roberts Read "Spacetime Physics"... (never mind Einstein's irrelevant verbiage). Androcles > There is no aether theory that is "experimentally indistiguishable" > from SR. The closest one is GGT (see the 1988 Gagnon paper on your own > website) and the Gagnon paper shows a way of separating GGT from SR. Much as I admire Gagnon (1988) for its -experimental- content, GGT as a "test theory" leaves much to be desired. The GGT transforms do not form a group, so in no way could GGT be considered the basis of a legitimate aether theory. The ease of separating GGT from SR is hence a bit "rigged." Gagnon's experimental setup provides, in my opinion, a true one-clock measurement of Delta-OWLS (i.e. OWLS anisotropy) (Tom would disagree), but even so, cannot distinguish between LET and SR. Trust me on this. I am on record in this newsgroup as having lost an argument on this subject, and I quite accept being the loser. Jerry > > There is no aether theory that is "experimentally indistiguishable" > > from SR. The closest one is GGT (see the 1988 Gagnon paper on your own [quoted text clipped - 12 lines] > Trust me on this. I am on record in this newsgroup as having lost an > argument on this subject, and I quite accept being the loser. Maybe. But this is because there is no description of LET, anye=where in any published paper, so LEt can claim that it is anything, including SR! I am talking about legitimate "aether" theories like Mansouri-Sexl and its close derivative GGT (CM Will talks about the same). Could it be that both Tom and I are right because we are dealing with different things? What is this damned LET? > Jerry > > > There is no aether theory that is "experimentally indistiguishable" > > > from SR. The closest one is GGT (see the 1988 Gagnon paper on your own [quoted text clipped - 15 lines] > Maybe. But this is because there is no description of LET, anywhere > in any published paper, Try Lorentz (1904) http://groups.google.com/group/sci.physics.relativity/msg/ec1b04f24018a5dd with the following commentary http://groups.google.com/group/sci.physics.relativity/msg/819d91d014849906 > so LEt can claim that it is anything, including SR! > I am talking about legitimate "aether" theories like Mansouri-Sexl and > its close derivative GGT (CM Will talks about the same). I don't know about Mansouri-Sexl, but the GGT transforms don't form a group. That kills it as a legitimate candidate physical theory. Try it out yourself! Does application of two Galilean transforms result in another Galilean transform? Yes. Does application of two Lorentz transforms result in another Lorentz transform? Yes. Does application of two GGT transforms result in another GGT transform? You tell me! > Could it be > that both Tom and I are right because we are dealing with different > things? What is this damned LET? Jerry > > > > There is no aether theory that is "experimentally indistiguishable" > > > > from SR. The closest one is GGT (see the 1988 Gagnon paper on your own [quoted text clipped - 38 lines] > > Jerry Jerry, It is very simple. There are quite a few papers published on GGT in Phys. Reviews. There are none on LET (what the hell is it?) See here: [url]http://prola.aps.org/abstract/PRA/v38/i4/p1767_1[/url] [url]http://prola.aps.org/abstract/PRD/v42/i2/p731_1?qid=6c4ab66eee46e0e8&...[/url] [url]http://prola.aps.org/abstract/PRD/v45/i2/p403_1?qid=630b0f834f891ba4&...[/url] [url]http://prola.aps.org/abstract/PRA/v34/i3/p1708_1[/url] [url]http://www.arxiv.org/PS_cache/physics/pdf/0508/0508097.pdf[/url] SNIP > > > > Gagnon's experimental setup provides, in my opinion, a true one-clock > > > > measurement of Delta-OWLS (i.e. OWLS anisotropy) (Tom would disagree), [quoted text clipped - 7 lines] > > > > Try Lorentz (1904) http://groups.google.com/group/sci.physics.relativity/msg/ec1b04f24018a5dd > > with the following commentary http://groups.google.com/group/sci.physics.relativity/msg/819d91d014849906 SNIP > > > Could it be > > > that both Tom and I are right because we are dealing with different [quoted text clipped - 6 lines] > It is very simple. There are quite a few papers published on GGT in > Phys. Reviews. There are none on LET (what the hell is it?) Note that the following comment is *not* for dda. For newcomers: Jerry already indicated above what in this newsgroup commonly (but not always!) is meant with "LET". In essence it's SRT as first taught by Lorentz and Poincare, a view that was shared by Langevin and Ives. They agreed on the theory of physics but their interpretation differed from both Einstein and Minkowski. Following quantum theory, "the Lorentz interpretation" would be unambiguous. Harald > See here: > > [url]http://prola.aps.org/abstract/PRA/v38/i4/p1767_1[/url] [url]http://prola.aps.org/abstract/PRD/v42/i2/p731_1?qid=6c4ab66eee46e0e8&.. .[/url] [url]http://prola.aps.org/abstract/PRD/v45/i2/p403_1?qid=630b0f834f891ba4&.. .[/url] > [url]http://prola.aps.org/abstract/PRA/v34/i3/p1708_1[/url] > > [url]http://www.arxiv.org/PS_cache/physics/pdf/0508/0508097.pdf[/url] > For newcomers: Jerry already indicated above what in this newsgroup commonly > (but not always!) is meant with "LET". In essence it's SRT as first taught [quoted text clipped - 3 lines] > interpretation" would be unambiguous. > Harald Well, thank you.You are in efeect telling me that SR is indistinguishable from SR! Duh! And I was thinking that you are talking about serious "aether' theories like Mansouri-Sexl or AVS. Meaning stuff published in peer reviewed journals and recognized as test theories of SR. Try reading Selleri for a change , or even better, read this: http://arxiv.org/abs/gr-qc/0409105 Serious (not "group-brewed") aether theories are distinguishable from SR. There is a hanful of experiments published in Phys.Rev that prove it. > > For newcomers: Jerry already indicated above what in this newsgroup commonly > > (but not always!) is meant with "LET". In essence it's SRT as first taught [quoted text clipped - 13 lines] > > http://arxiv.org/abs/gr-qc/0409105 Nice article - indeed they also explain why the "paradigm" of Lorentz and Poincare is experimentally indistinguishable from SRT. Harald > Serious (not "group-brewed") aether theories are distinguishable from > SR. There is a hanful of experiments published in Phys.Rev that prove > it. >> http://arxiv.org/abs/gr-qc/0409105 > > Nice article [...] But this whole concern about "synchronization gauges" and such is really an _engineering_ issue, not one of physics. The distinction is: engineers measure things, while scientists _test_theories_. If you are going to measure the one-way speed of anything, how you synchronize your clocks will be important, and will directly affect your result. But if you are testing a theory, how you synchronize your clocks is _completely_irrelevant_. Note that how you choose to synchronize your clocks is an arbitrary human choice, and cannot possibly affect any underlying physical phenomena. An example I have often used: Let's consider the one-way propagation of light over a distance L of 10 meters, with endpoints in different timezones on earth. Set the clocks at the ends to UTC plus their respective timezone offsets. These clocks are not synchronized in any inertial frame, and if you use this setup to "measure the speed of light" you will of course get crazy results. But testing SR is quite sensible: SR predicts that light will require a time c/L to propagate this distance when measured using locally inertial coordinates. So pick the locally inertial frame of one clock, extend its coordinates to the location of the other, and clearly the clock used in the experiment is offset by 1 hour from these coordinates. So SR, as applied to the conditions of this experiment, predicts a clock reading that will be quite close to the actual reading (in practice, within the resolutions of the clocks). The point is: physical theories include a context for their predictions, and that context must be applied to the conditions of the experiment. Simply "measuring things" does not inherently provide such a context, and one must be obtained by some other means. So engineers must worry about synchronization conventions and gauges; physicists need not, as long as they remember their job is to _test_theories_. Tom Roberts > > I don't know about Mansouri-Sexl, but the GGT transforms don't form > > a group. That kills it as a legitimate candidate physical theory. [quoted text clipped - 3 lines] > > application of two GGT transforms result in another GGT transform? > > You tell me! > It is very simple. There are quite a few papers published on GGT in > Phys. Reviews. There are none on LET (what the hell is it?) One thing to beware of, is that the letters "GGT" used as an acronym for "Generalized Galilean Transform" may stand for a variety of distinct test theories. So if you wish to claim that GGT is a widely used test theory, I would counter with the same response you make towards LET, namely, what do you mean by it? I have already explained to you why the GGT of Gagnon cannot be considered a legitimate candidate physical theory. Jerry > > > > There is no aether theory that is "experimentally indistiguishable" > > > > from SR. The closest one is GGT (see the 1988 Gagnon paper on your own [quoted text clipped - 38 lines] > > Jerry OK, so LET is Lorentz's 1904 theory. And I was taking to be a seriuos aether theory in the vein of Mansouri-Sexl (1977). No wonder LET is not present in any publication. The last time it was published was 1904. Come on guys, people read Tom Roberts' web page and they take the statements to refer to serious "aether" theories , like Mansouri-Sexl. > > > > There is no aether theory that is "experimentally indistiguishable" > > > > from SR. The closest one is GGT (see the 1988 Gagnon paper on your own [quoted text clipped - 38 lines] > > Jerry Jerry, GGT and MS are consacrated and recognized test theories of SR. LET is not. Would you please read the Phys>Rev. papers I sourced? > GGT and MS are consacrated and recognized test theories of SR. LET > is not. Would you please read the Phys Rev. papers I sourced? First of all, I note there is more than one "GGT" in the literature. Until somebody -explicitly- shows me that Gagnon's version of GGT satisfies group properties, I will continue to rely on my own math. My own math showed that two successive applications of Gagnon's GGT transform did not result in a GGT transform. Now, I'm not the greatest mathematician in the world, and YES, I could have messed up, so if you wish to show me that Gagnon's GGT satisfies group properties, please do so. I am on record as a person who admits their mistake. Russ and Sal can both attest to that, since I've been on the losing end of arguments with both of them. I will read the papers when I get to the main campus library. I'm a poverty-stricken med student, and I have never claimed to be anything other than an interested amateur. I log on when I'm sick of studying pathology and pharmacology. Physics is strictly a hobby for me, and I don't want to spend the money to download the papers from the Phys. Rev. site. So you'll have to wait. Jerry > > GGT and MS are consacrated and recognized test theories of SR. LET > > is not. Would you please read the Phys Rev. papers I sourced? [quoted text clipped - 18 lines] > > Jerry Jerry There is only one GGT. It is described by the so-called Tangerlini transforms. I will send you a link to the Gagnon paper where you don't have to buy it in order to read it. Once more : GGT and MS are the "de facto" test theories for SR. LET is not. If Tom is refering to LET in his webpage, then the point is moot . Sill, it would be good if he made a clearpage in this sense statement on his web page in this sense. > > > GGT and MS are consacrated and recognized test theories of SR. LET > > > is not. Would you please read the Phys Rev. papers I sourced? [quoted text clipped - 24 lines] > transforms. I will send you a link to the Gagnon paper where you don't > have to buy it in order to read it. If you mean http://imaginary_nematode.home.comcast.net , that's -my- web site, thank you. I just finished putting up Fox(1977) and Babcock and Bergman (1964). Jerry > If you mean http://imaginary_nematode.home.comcast.net , > that's -my- web site, thank you. I just finished putting up Fox(1977) > and Babcock and Bergman (1964). > > Jerry Excellent, thank you. What a small world! > > GGT and MS are consacrated and recognized test theories of SR. LET > > is not. Would you please read the Phys Rev. papers I sourced? [quoted text clipped - 18 lines] > > Jerry Jerry There is only one GGT. It is described by the so-called Tangerlini transforms. I will send you a link to the Gagnon paper where you don't have to buy it in order to read it. Once more : GGT and MS are the "de facto" test theories for SR. LET is not. If Tom is refering to LET in his webpage, then the point is moot . Sill, it would be good if he made a clear statement in this sense on his web page. Just to clear the confusion it created. > There is only one GGT. It is described by the so-called Tangerlini > transforms. [...] > Once more : GGT and MS are the "de facto" test theories for SR. LET is > not. GGT / Tangherlini transform is not really a test theory, it is a specific instance of the test theory of Mansouri and Sexl. > If Tom is refering to LET in his webpage, then the point is moot . I am not just referring to LET (though I do single it out as a special case). I am referring to every one of the test theories of MS such that the round-trip speed of light is isotropically c in every inertial frame. This class of theories includes GGT / Tangherlini transform. To me, LET is not "the same theory" as SR, because it differs in both choice of postulates and interpretation of symbols. But in terms of the MS test theory they both have the same values of all parameters. Tom Roberts > > There is only one GGT. It is described by the so-called Tangerlini > > transforms. [...] [quoted text clipped - 3 lines] > GGT / Tangherlini transform is not really a test theory, it is a > specific instance of the test theory of Mansouri and Sexl. Whatever, let's not split hairs. > > If Tom is refering to LET in his webpage, then the point is moot . > [quoted text clipped - 6 lines] > choice of postulates and interpretation of symbols. But in terms of the > MS test theory they both have the same values of all parameters. OK, fine. I hope that after the several papers I quoted you are not saying that Mansouri-Sexl is experimentally indistinguishable from SR. This is the core of our discussion. > OK, fine. I hope that after the several papers I quoted you are not > saying that Mansouri-Sexl is experimentally indistinguishable from SR. > This is the core of our discussion. Of course not! Only the specific subset of the MS test theory I mentioned before is experimentally indistinguishable from SR. Basically this subset differs from SR only in the way coordinate clocks are synchronized; as clock synchronization is conventional [#], this is an unobservable difference. In particular, for any of these theories, slow clock transport yields Einstein-synchronized clocks, not coordinate-synchronized clocks (in SR of course those are the same). [#] You can synchronize your clocks any way you choose to do so. Of course once you make measurements using them you must include the synchronization procedure in the analysis, in order to compare to any theory. Tom Roberts > > OK, fine. I hope that after the several papers I quoted you are not > > saying that Mansouri-Sexl is experimentally indistinguishable from SR. [quoted text clipped - 14 lines] > > Tom Roberts Excellent! It would be great if you added these lines on your website, there are quite a few people that misunderstood (and still do) and misinterpreted (and still do) what is shown on the page. Perhaps adding a more mathematical presentation would also help. I think we are done, correct? $$ [1] Sam [ -worms ] Wormley writes tomgee: > > So it doesn't matter what the definition of constant > > velocity is, to you, right? You will define it and use > > any way you want to, right? After all, it's a free > > country and you can make up anything you want, right? > > There is only one definition dv/dt = 0 $$ Where, dv/t = x ..and, v/dt = y. [ SPEED is ANY PATH/duration ; VELOCiTY the VECTOR/duration. ] $$ You need BOTH velocity vector END-POiNT positions at ONCE. $$ The VELOCiTY is ALWAYs known _ONLY_ in retrospect, so 'dv' $$ caN'T EVER be known, at ONCE (i.e. ..at ANY *SiNGLE* 't'). $$ Atomic giga-frequency counters of REAL time. The BEST atomic clock is SiMPLY a GiGA-frequency-COUNTER.!! And, even the VERY best ATOMiC clocks CANNOT be SYNCRONiZED TOGETHER, at once, on any GR or any OTHER sort of Ph.Tivity TiME-line (i.e. WORLD-line), in ANY SPACE-time-continuum.!! $$ All "clocks" are simply various FREQUENCY-COUNTERs used even since very early on in PRE-history (to wit, period tally-marks ..on excavated sticks & bones), to "TRY-to" *CLOCK* ..the "REAL TiME".!! NOT to mention SUN & MOON. However, a sort of TiME-AVERAGED simultaneity is achievable ..all having to compensate (REset) for design mysteries.!! $$ DELTA v, (dv), caN'T *HAPPEN* ..all at ONCE. $$ Simultaneity happens AT ONCE; EveryTHiNG else needs TiMiNG. $$ And, *REAL* TiME is why *SHOP (LAB)* TiME has *ERROR* bars. $$ ANY clock MOViNG ..or MOVED any LOWER ..will run FASTER.!! $$ ANY clock MOViNG ..or MOVED any HiGHER, will run SLOWER.!! $$ ANY clock's HORiZONTAL "SLOW transport", is UP transport. $$ ANY clock moving OUT [ HORZ ] on a turn table", moves UP. $$ ANY clock VARiES in ALTiTUDE for ANY horizontal TRANsPORT. $$ Three VELOCiTY vector END-POiNT positions REQUiRED, for dv. $$ Three VELOCiTY vector END-POiNTs (3 positions) define a dv. $$ [GR Tivity CRACKED-pots: NOTE 'dt' caN'T HAPPEN ..at ONCE]. $$ Sam Wormly ..delta t (dt), PERiOD. "It takes an infinite amount of time ..at which point,..". -- Sam [ -worms ] Wormley. >><> >><> >><> >><> >><> $$ [2] Delta t (dt), PERiOD. $$ Tom [ He between his error-bars ] Roberts [@GR.BUFFY.com] wrote: > vanep@cox.net wrote: > > [someone] might conclude that GR predicts proper clock rates [quoted text clipped - 8 lines] > That is, one cannot differentiate > with respect to readings on a clock, $$ Tom you know GPS scientists use SEVERAL-clock's _average_ t. $$ THERE would be NO NEED of SEVERAL-clocks, if you were RiGHT. $$ $$ [The MORE atomic-TiCKERs ..the BETTER "clocking"-AVERAGE t]. $$ [MORE atomic-TiCs/STANDARD TiC; BETTER clocking _ACCURACY_]. $$ [Our STANDARD TiC-TOC TiME is STiLL Least-Squares-adjusted]. $$ $$ [TiME is the POiNT where the clock sits on it's WORLD-line]. $$ [TiMiNG is the *DiFFERENTiATiON* of DiSTiNGUiSHABLE POiNTs]. $$ [ -- A *MAGNiTUDE*-of-a-TiMiNG is WHAT a clock "READs" -- ]. $$ $$ COMPULSORY selection; ARBiTRARY choice. $$ [Clock-READiNG: An UNadjusted MAGNiTUDE-of-TiMiNG counted ]. $$ [ANY "clock" is a *totally _ARBiTRARY_* human construction]. $$ [The clock-"READiNG" is ALSO a totally _ARBiTRARY _ choice]. $$ $$ [ i.e. NATURE does NOT mind if we have COHERENT STANDARDs ]. $$ $$ And the ARBiTRARiNESS is "of _CHOiCE_" not _SELECTiON_, duh. $$ [ i.e. The CHOiCE is ARBiTRARY ..a SELECTiON is COMPULSORY]. $$ $$ You ARBiTRARiLY CHOOSE a COMPULSORY STANDARD ..then MEASURE. > -=- only with respect to some coordinate. > But you can arrange for that coordinate to > track the readings of the clock. > > I don't think we are in serious disagreement here, > just terminology. $$ [ALPHABET is ARBiTRARY but we SELECT our CHOiCE, to WRiTE]. $$ $$ And "_all_ rates" areN'T just functions-of-TiMiNG ..dimwit. Re: COMPULSORY selection; ARBiTRARY choice ..of the STANDARD set. Re: NATURE doesN'T mind if we have COHERENT STANDARDs. Re: Delta t (dt), PERiOD. ..End of 2 rePOSTs. |> [#] You can synchronize your clocks any way you choose to do so. |> Tom [ He between his error-bars ] Roberts ..@ GR.BUFFY.com. Re: < alt.sci.nanotech > ; Re: < bit.org >. | Gagnon's experimental setup provides, in my opinion, a true one-clock | measurement of Delta-OWLS (i.e. OWLS anisotropy) (Tom would disagree), [quoted text clipped - 4 lines] | | Jerry Ok, so you cannot distinguish between bright green flying elephants and dark red walking fish. I'll trust you that far. BTW, how many angels dance on the head of a pin? Androcles. >> There is no aether theory that is "experimentally indistiguishable" >> from SR. The closest one is GGT (see the 1988 Gagnon paper on your own >> website) and the Gagnon paper shows a way of separating GGT from SR. This is wrong. The theory used in that paper is the Tangherlini transform, and it is a member of the class of theories that are experimentally indistinguishable from SR. > Much as I admire Gagnon (1988) for its -experimental- content, GGT > as a "test theory" leaves much to be desired. The GGT transforms > do not form a group, so in no way could GGT be considered the basis > of a legitimate aether theory. Those transforms do not obey the Principle of Relativity, and do not form a group in which all inertial frames are equivalent, but they are a legitimate basis for an aether theory. > Gagnon's experimental setup provides, in my opinion, a true one-clock > measurement of Delta-OWLS (i.e. OWLS anisotropy) (Tom would disagree), Yes. It simply is not possible to measure OWLS with a single clock, and this approach does not do so. > but even so, cannot distinguish between LET and SR. That is true. Nor can it distinguish the Tangherlini transform from SR. Tom Roberts > > Gagnon's experimental setup provides, in my opinion, a true one-clock > > measurement of Delta-OWLS (i.e. OWLS anisotropy) (Tom would disagree), > > Yes. It simply is not possible to measure OWLS with a single clock, and > this approach does not do so. Nor did I ever state that they were doing so. They do not measure OWLS, but Delta-OWLS. That's a huge difference. You never answered me where was the second clock. Jerry | > > Gagnon's experimental setup provides, in my opinion, a true one-clock | > > measurement of Delta-OWLS (i.e. OWLS anisotropy) (Tom would disagree), [quoted text clipped - 6 lines] | | You never answered me where was the second clock. "And you never responded to how a 2-d surface in a flat 4-d spacetime can have nonzero curvature, and why that shows that the curvature of such "2-d surfaces is useless in "describing" the geometry of the 4-d manifold... -- Tom Roberts Humpty Roberts let out a great sigh. " <sigh>", he said. "The nuances of English. I was discussing the usage of words and not the concepts they represent." -- Tom Humpty Roberts " To obtain a speed, you must divide the distance traveled by the travel time, and _all_ quantities _must_ be measured in a single coordinate system. _Nothing_ else is speed. Because that is what we mean by the word. <shrug>" -- Humpty Roberts "Yes, tests of strong fields are few and far between, but there are some: the binary pulsars, and observations of accretion disks near black holes -- Humpty Roberts `I don't know what you mean by "observations",' Jerry said. Humpty Roberts smiled contemptuously. `Of course you don't -- till I tell you. I meant "there's a nice knock-down argument for you!"' <shrug> `But "observations" doesn't mean "a nice knock-down argument",' Jerry objected. `When I use a word,' Humpty Dumpty said, in rather a scornful tone, <shrug>, `it means just what I choose it to mean -- neither more nor less.' <shrug>. "Jerry in Wonderland" -- Lewis Androcles Carroll > It (as was already known) showed that the TWLS was constant. > It did not disprove (modern) ehter theory because ether theory predicts > that there would be no fringe shift. But the 'earlier' ether theory was > badly interpreted and was thought that it it predicted a fringe shift. Modern "aether" theories are (and have been) disproved by OWLS experiments. > > It (as was already known) showed that the TWLS was constant. > > It did not disprove (modern) ehter theory because ether theory predicts [quoted text clipped - 3 lines] > Modern "aether" theories are (and have been) disproved by OWLS > experiments. Such "disproof" is based on erroneous (and circular) reasoning, as Ives also showed in some of his papers. For such experiments you mostly "measure" what you first defined. http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#one-way%20tests Harald > > > It (as was already known) showed that the TWLS was constant. > > > It did not disprove (modern) ehter theory because ether theory predicts [quoted text clipped - 10 lines] > > Harald Again: words from an obvious "aether theorist". I am not interested in your bias, I am interested in Tom's response. > > > > It (as was already known) showed that the TWLS was constant. > > > > It did not disprove (modern) ehter theory because ether theory predicts [quoted text clipped - 7 lines] > > showed in some of his papers. For such experiments you mostly "measure" what > > you first defined. http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#one-way%20tests > > Harald > > Again: words from an obvious "aether theorist". I am not interested in > your bias, I am interested in Tom's response. It would be nice if I were... and well known facts have nothing to do with bias. > Hi > > In the MM experiment, was the length of the two light paths set > exactly equal. If so, how was this done? How do you normally determine if two lengths are the same? - measurement. > If not, did the experiment > "rely" on the fact that there was no change in the interference > fringes when the apparatus was rotated? > > Did the MM experiment demonstrate anything about the constancy of the > speed of light It demonstrated that two way light speed was the same in a frame that is for all practical purposes was inertial. > or did it merely "disprove" the aether theory? It do not disprove the aether since aether theories (the good ones) make predictions exactly the same as SR. http://www.google.com/groups?selm=3838AC00.87B78404%40lucent.com http://www.google.com/groups?selm=3838A838.81CE8090%40lucent.com http://www.google.com/groups?selm=3838AA2A.829F46AD%40lucent.com Bill > Does this website have any credibility in mainstream physics? > http://home.iprimus.com.au/longhair1/page1.html > > Thanks. > It demonstrated that two way light speed was the same in a frame that is for > all practical purposes was inertial. [quoted text clipped - 8 lines] > > Bill ......They don't make the same predictions. See the OWLS experiment by Gagnon (Phys.Rev.A 1988) on John Baez's page. > In the MM experiment, was the length of the two light paths set > exactly equal. Yes, to within a fraction of a wavelength. This was necessary so the white light fringes could be seen, and so the center fringe could be uniquely determined -- at the edge of each white fringe there is a rainbow, and this rainbow changes sides at the center. When the center fringe is in the center of the field-of-view, the light paths are exactly equal (to the accuracy of centering the fringe, expressed in fractional wavelengths). There are several incorrect answers in this thread. For white light fringes to be visible, the light paths _must_ be equal to within a fraction of a wavelength. Kennedy and Thorndike did indeed use unequal arms, but they used monochromatic light from a source with a long coherence length. You can learn all this just by reading the papers. <shrug> > If so, how was this done? They did it by carefully adjusting their mirrors. Michelson and Morley did not go into detail in their paper, IIRC, but Miller did (Miller worked at the same school, collaborated with Morley, and used portions of the MMX apparatus in his interferometer). Miller started with dowel rods to make the light paths equal to a mm or so, then used sodium light to find its center fringe and adjust the light paths so it filled the entire field of view, then used white light and found the fringes and adjusted so the center fringe is near the center of the field-of-view (he was unable to keep it there for long because of instabilities). Anyone who has ever used such an interferometer, in school perhaps, knows how difficult it is to adjust for white fringes. Monochromatic fringes are _much_ easier, because the light paths can differ in length by the coherence length of the source; for a neon bulb that is a few mm (what we used), and for a laser it can be 10s of cm up to several meters (do not look into laser with remaining eye (:-)). > If not, did the experiment > "rely" on the fact that there was no change in the interference > fringes when the apparatus was rotated? The experiment _measured_ the change in the fringe pattern as the interferometer rotated. Unfortunately it also measured a rather large systematic error. Due to the limitations of the day, neither Michelson and Morley nor Miller fully understood their measurements to the extent we can do so today; and of course they had no digital computers to use in the analysis. > Did the MM experiment demonstrate anything about the constancy of the > speed of light or did it merely "disprove" the aether theory? Neither. It established an upper bound on the anisotropy of the round-trip speed of light, and thus an upper bound on the motion of the earth relative to the ether using the then-current ether theory. Their upper bound on the earth's speed relative to the ether was 7.5 km/s, which is 1/4 the earth's orbital speed, and this solidly refuted the then-current ether theory. There are people who claim the Michelson-Morley experiment actually had a non-null signal. There are many more who claim Miller had a non-null result (including Miller himself). All are wrong, and fooled themselves by: a) not fully understanding the measurement using modern techniques, and b) not performing a _quantitative_ error analysis. Of course Michelson, Morley, and Miller can all be excused for not knowing about techniques learned after their deaths; modern advocates have no such excuse. Neither the MMX nor Miller had any _significant_ signal (I'm writing a paper on this). > Does this website have any credibility in mainstream physics? > http://home.iprimus.com.au/longhair1/page1.html A 30-second scan shows it has a large number of the hallmarks I associate with cranks and crackpots. It does not appear interesting to me. I cannot speak for "mainstream physics", but I am an active participant in it. Tom Roberts tjroberts@lucent.com > > In the MM experiment, was the length of the two light paths set > > exactly equal. > > Yes, to within a fraction of a wavelength. Minor quibble: During the course of a single turn, Michelson and Morley experienced thermal drift amounting to as much as 0.6 wavelengths; likewise Miller often experienced over two fringes of thermal drift per turn, so stating that the light paths were set equal to within "a fraction of a wavelength" implies somewhat greater stability of their apparatus than they actually were able to maintain. On the other hand, the expression that I used in -my- post, "within microns", errs in the opposite direction. The coherence length of white light is about a micron, but I was guessing that yellow acetylene light would show a longer coherence length, and I neglected to double check the papers as to how accurately they actually centered the fringes. > This was necessary so the > white light fringes could be seen, and so the center fringe could be [quoted text clipped - 3 lines] > exactly equal (to the accuracy of centering the fringe, expressed in > fractional wavelengths). Jerry | > > In the MM experiment, was the length of the two light paths set | > > exactly equal. [quoted text clipped - 8 lines] | implies somewhat greater stability of their apparatus than | they actually were able to maintain. Major quibble. Roberts is a complete idiot, the lengths of the light paths need only be an exact multiple of the lowest common denominator. But then, half the time Humpty Roberts is babbling about the meaning of words, the other half his lack of knowledge. In this GIF http://tinyurl.com/h2g7z the arms are in the ratio 3:4 and the speed of light is zero as shown by the standing frequency. 1:1 ,2:1, 3:1, 3:2 would all work. So would 1,000,000: 999,999. The aether wind (yellow arrows) has no effect. The distances before (East) and after (South) of the beamsplitter are of no consequence whatosover. Androcles. | On the other hand, the expression that I used in -my- post, | "within microns", errs in the opposite direction. The coherence [quoted text clipped - 12 lines] | | Jerry > There are people who claim the Michelson-Morley experiment actually had > a non-null signal. There are many more who claim Miller had a non-null [quoted text clipped - 5 lines] > excuse. Neither the MMX nor Miller had any _significant_ signal (I'm > writing a paper on this). Maurice Allais (Nobel Prize Winner for Economy!) is one of the worst offenders. Another source of error is that MM did not consider the diurnal variation in the Earth speed, i.e. their "beta"=v/c and their "gama"=1/(1-(v/c)^2)^1/2 use VARIABLE v. Tom, When and where do you plan to publish your paper? I would be interested. >> Neither the MMX nor Miller had any _significant_ signal (I'm >> writing a paper on this). > > Maurice Allais (Nobel Prize Winner for Economy!) is one of the worst > offenders. Yes. But he is by no means alone. I cite more than a dozen recent papers that assume Miller's result is real. > Another source of error is that MM did not consider the diurnal > variation in the Earth speed, i.e. their "beta"=v/c and their > "gama"=1/(1-(v/c)2)1/2 use VARIABLE v. That variation is on the order of 500 m/s, and their upper bound is 7,500 m/s, so this is not significant. Moreover, they measured at the same time of day over a period of just 4 days, so the actual variation is considerably smaller. > When and where do you plan to publish your paper? I would be > interested. I expect to put it up on the preprint servers within a week or two (I have a complete second draft in hand). I will be submitting it to Rev. Mod. Phys. (where Miller published his results so long ago). There's no guarantee they will accept it, of course.... Anybody who wishes to do so can send me a private email to the address listed below and if I think you're serious I'll add you to my list of people to be notified. If you monitor this newsgroup that's not really necessary, as I'll also post a message here when I get it onto the preprint servers. I expect a vigorous discussion in this newsgroup, and a more serious one via email. BTW I am giving a colloquium on this, next week in Chicago, IL USA. If anyone is interested, email me and if I think you are serious I will send you the details. Tom Roberts tjroberts137@sbcglobal.net > > Tom Roberts wrote: > >> Neither the MMX nor Miller had any _significant_ signal (I'm [quoted text clipped - 14 lines] > same time of day over a period of just 4 days, so the actual variation > is considerably smaller. Yes, it is small. It does not stop some from mistaking the sine wave behavior of v as a way of "detecting the absoulute motion of Earth". Have you seen this (it is not an April Fool joke): http://arxiv.org/PS_cache/astro-ph/pdf/0604/0604145.pdf > Hi > > In the MM experiment, was the length of the two > light paths set exactly equal. No. > If so, how was this done? > If not, did the experiment "rely" on the fact that > there was no change in the interference fringes > when the apparatus was rotated? They wanted to measure a difference, but found out there was none. > Did the MM experiment demonstrate anything about > the constancy of the speed of light or did it > merely "disprove" the aether theory? None of the above : it only showed that physics was entirely different than previously thought of. Suddenly, time was variable, length was variable, mass was variable. If you want my opinion, which is not mainstream physics yet : There is an inertial field, caused by mass. All the masses in the universe contribute to this, and this makes sort of an absolute reference. Gravitation is only caused by a gradient of this field. If you move through this field, you experience higher inertia in the direction of motion. Nearing c inertia nears infinity, and it is impossible to accelerate further. A clock is an inertiameter. It just measures the inertial field : more masses around your inertiameter (formerly called clock) and it moves slower. Make it move near light speed, and it slows down too : not its heavy mass increases, but its inertia, and since it is an inertiameter, it simply reacts to it. No magic there, just simple physics. The inertial field makes objects shrink : mainstream today calls this "gravitational length contraction". ( gravitation arises from an inertial field with a gradient. That is why they are equivalent,see Eotvos experiments) And for Uncertainty and QM there is a simple explanation to : As the macroworld is fully completely based on inertia, (restating the relativity principle in inertial terms means : inertia affects all physical processed in such a way that the local observer never can tell his local inertia), the quantum world and uncertainty derives its properties just on the lack of inertia. Inertia keeps objects that do not undergo external influences in one place, but take inertia away and objects have an uncertain "zitterbewegung". > Does this website have any credibility in > mainstream physics? > http://home.iprimus.com.au/longhair1/page1.html It looks good : there are lots of links to original documents, you can learn more from them than from contemporary cultist "interpretations". You see the difficulty for instance Rutherford had in deducing his view on the atom. (I just read the link to his 1914 paper, I think it is wonderfull) Mainstream physics, before the MM xperiment, assumed there was an aether, for all the wrong reasons, they needed a substance that "waved", like water molecules constitute the sea wave. Now mainstraim physics thinks that they do not need an Aether. That should give you an indication about the value of mainstream physics. Science is in bad shape : it has become religious again lately. Look here http://www.xs4all.nl/~notime/Duesberg_On_Science.html http://www.redflagsdaily.com/audio/RF_Podcast_06_jan.htm http://www.virusmyth.net/aids/data/cjinterviewep.htm http://www.virusmyth.net/aids/data/besmon.htm Uwe Hayek.  SignatureDie wirtschaftliche Freiheit hat keine Sicherheit ohne Politische Freiheit, und die politische findet ihre Sicherheit nur in die wirtschaftlichen Freiheit." -- Eugen Richter This is the bitterest pain among men, to have much knowledge but no power. Herodotus (484 BC - 430 BC), The Histories of Herodotus IDIOCY - Never underestimate the power of stupid people in large groups. > Hi > > In the MM experiment, was the length of the two > light paths set exactly equal. No. > If so, how was this done? > If not, did the experiment "rely" on the fact that > there was no change in the interference fringes > when the apparatus was rotated? They wanted to measure a difference, but found out there was none. > Did the MM experiment demonstrate anything about > the constancy of the speed of light or did it > merely "disprove" the aether theory? None of the above : it only showed that physics was entirely different than previously thought of. Suddenly, time was variable, length was variable, mass was variable. If you want my opinion, which is not mainstream physics yet : There is an inertial field, caused by mass. All the masses in the universe contribute to this, and this makes sort of an absolute reference. Gravitation is only caused by a gradient of this field. If you move through this field, you experience higher inertia in the direction of motion. Nearing c inertia nears infinity, and it is impossible to accelerate further. A clock is an inertiameter. It just measures the inertial field : more masses around your inertiameter (formerly called clock) and it moves slower. Make it move near light speed, and it slows down too : not its heavy mass increases, but its inertia, and since it is an inertiameter, it simply reacts to it. No magic there, just simple physics. The inertial field makes objects shrink : mainstream today calls this "gravitational length contraction". ( gravitation arises from an inertial field with a gradient. That is why they are equivalent,see Eotvos experiments) And for Uncertainty and QM there is a simple explanation to : As the macroworld is fully completely based on inertia, (restating the relativity principle in inertial terms means : inertia affects all physical processed in such a way that the local observer never can tell his local inertia), the quantum world and uncertainty derives its properties just on the lack of inertia. Inertia keeps objects that do not undergo external influences in one place, but take inertia away and objects have an uncertain "zitterbewegung". > Does this website have any credibility in > mainstream physics? > http://home.iprimus.com.au/longhair1/page1.html It looks good : there are lots of links to original documents, you can learn more from them than from contemporary cultist "interpretations". You see the difficulty for instance Rutherford had in deducing his view on the atom. (I just read the link to his 1914 paper, I think it is wonderfull) Mainstream physics, before the MM xperiment, assumed there was an aether, for all the wrong reasons, they needed a substance that "waved", like water molecules constitute the sea wave. Now mainstraim physics thinks that they do not need an Aether. That should give you an indication about the value of mainstream physics. Science is in bad shape : it has become religious again lately. Look here http://www.xs4all.nl/~notime/Duesberg_On_Science.html http://www.redflagsdaily.com/audio/RF_Podcast_06_jan.htm http://www.virusmyth.net/aids/data/cjinterviewep.htm http://www.virusmyth.net/aids/data/besmon.htm Uwe Hayek. SignatureDie wirtschaftliche Freiheit hat keine Sicherheit ohne Politische Freiheit, und die politische findet ihre Sicherheit nur in die wirtschaftlichen Freiheit." -- Eugen Richter This is the bitterest pain among men, to have much knowledge but no power. Herodotus (484 BC - 430 BC), The Histories of Herodotus IDIOCY - Never underestimate the power of stupid people in large groups. > Does this website have any credibility in mainstream physics? > http://home.iprimus.com.au/longhair1/page1.html I read some more on this website, and it is absolute junk. Read only the links to the original documents. Uwe Hayek. SignatureDie wirtschaftliche Freiheit hat keine Sicherheit ohne Politische Freiheit, und die politische findet ihre Sicherheit nur in die wirtschaftlichen Freiheit." -- Eugen Richter This is the bitterest pain among men, to have much knowledge but no power. Herodotus (484 BC - 430 BC), The Histories of Herodotus IDIOCY - Never underestimate the power of stupid people in large groups. >Hi > >In the MM experiment, was the length of the two light paths set >exactly equal. If so, how was this done? If not, did the experiment >"rely" on the fact that there was no change in the interference >fringes when the apparatus was rotated? If monochromatic light is used, the distances are not critical. The fringes become broader as the equal distances are approached. With perfect mirrors, one firnge will cover the whole field of view. >Did the MM experiment demonstrate anything about the constancy of the >speed of light or did it merely "disprove" the aether theory? The MMX merely proved that light moves at c wrt its source and everything in the source frame. >Does this website have any credibility in mainstream physics? >http://home.iprimus.com.au/longhair1/page1.html it should be OK...It's written by an aussie. ...but he looks like an aetherist to me. >Thanks. HW. www.users.bigpond.com/hewn/index.htm See the section on the Michelson Morley expt at: http://en.wikibooks.org/wiki/Special_relativity The full calculation for the fringe shifts is given. The paths do not need to be identical, have a look at the denominators in the formula for the change in transit times with a rotation. Best wishes Alex Green > See the section on the Michelson Morley expt at: > http://en.wikibooks.org/wiki/Special_relativity OK. There are a number of minor errors, mostly historical minutiae, but all-in-all quite reasonable. > The paths do not > need to be identical, They need to be equal to within the coherence length of the source or the fringes won't be visible (that's what coherence length means). For the white light used by Michelson and Morley, and by Miller, this coherence length is less than a millimeter. That's why they tuned it up with sodium or mercury lights, which have much longer coherence lengths. Both of them measured the position of the central fringe, and for that to be visible the paths must be equal to within a few wavelengths. Tom Roberts Tom, this is a very good point. Those unfamiliar with coherence length see: http://en.wikipedia.org/wiki/Coherence_length Of course, MM did not have helium-neon lasers with a 20 cm coherence length as a source. Here is an excellent reference to the MM experiment explaining the construction in more depth: http://www.phy.davidson.edu/StuHome/cabell_f/diffractionfinal/pages/Michelson.htm I found this quote from some people who still play with Michelson interferometers: "With white light, however, which has a large linewidth (includes wavelengths from 400-700 nm), it is simple to make the interference effects disappear because it exhibits a coherence length on the order of 10^-3 mm. This means that if the two arms of the interferometer differ by that tiny amount, then no interference patterns will be visible. " http://www.phy.davidson.edu/StuHome/cabell_f/diffractionfinal/pages/history.htm# Coherence So, the arms can differ in length by less than a micron if white light is used! Best wishes Alex Green > See the section on the Michelson Morley expt at: > [quoted text clipped - 7 lines] > > Alex Green Thank you for the website, looks like a very good treatment. A few interesting points: 1. The Lorentz-FitzGerald contraction was refuted by two experiments: Trouton-Noble (1904) and Troton-Rankine (1908) 2. There are some very interesting reenactments of MMX that use medium with refringency n>1. These experiments are listed on Tom's page and they confirm MMX (and SR) with a very high precision. 2. Despite points 1 and 2, there is a class of nuts that insist that reenacting MMX in a medium with n>>1 can detect the Earth motion. Here is a better one (can you spot the error?): http://arxiv.org/PS_cache/physics/pdf/0310/0310053.pdf Here is a much worse one : http://arxiv.org/PS_cache/physics/pdf/0508/0508174.pdf The second one was even published in "Progress in Physics" despite its glaring errors. Both papers are patently wrong. Can you find the errors? |
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