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Natural Science Forum / Physics / Relativity / October 2005failure of Michelson-Morley?
Hello, I'm not sure how Michelson-Morley conducted their famous experiment, but to me they shown that aether (the medium which carries light) has a velocity of zero (no aether winds in free space). The conclusion that soon follow: the speed of light is independent of all moving reference frame seam ad hoc reasoning. Consider sound wave in a medium (like air, with medium velocity = zero) it radiates in all directions at constants speed and produce a Doppler shift in a relativistic reference frame. The same is true for light. The Doppler shift of wavelength and the BEC experiment suggest the speed of light is medium specific (free space is a fix medium/aether with velocity = 0). Just as you do not directly add the sound wave velocity to the observer velocity... why would you do it for light. In 1998, laser pulses were slowed in a Bose-Einstein condensate (BEC) of sodium to only 17 m/s, more than seven orders of magnitude lower than the speed of light in vacuum. It experiment shows that if the light medium is moving, then you can add the velocity of the medium to the velocity of the propagation light, just like sound in air. On an astrological scale, phenomenon's dealing with simultaneous events, time dilation, and length contraction can be explained by considering the time delay of light. The time it takes light to travel to the observer with the event information. For instant, when you view a rod traveling very fast, you view photons carrying the back of the rod and the front of the rod simultaneously (one instant of time). The rod appears to shrink because photons carrying the true front position is not synchronized with the photons carrying the true rear position, the front photon must travel the length of the rod to be synchronized with the rear. The problems I'm having with this classical view of relativity is I do get a one to one formulas match with the Lorentz transforms. That might be because I'm not assuming c for all reference frames. I argue you can't measure particles moving faster than the speed of light because of the inherit propagation delay, but I do not know why all moving inertial reference frame must measure the same speed of light. They explain this by defining space-time as a curve, so that Galilean geometry isn't appropriate. My point is the null results of the Michelson-Morley experiment is insufficient evident to conclude "speed of light is independent of all moving reference frame". King > Hello, > [quoted text clipped - 3 lines] > speed of light is independent of all moving reference frame seam ad hoc > reasoning. It is not a conclusion. It is a hypothesis that could explain the result. > Consider sound wave in a medium (like air, with medium velocity = zero) it > radiates in all directions at constants speed and produce a Doppler shift in [quoted text clipped - 15 lines] > time dilation, and length contraction can be explained by considering the > time delay of light. Actually they can't. > The time it takes light to travel to the observer with > the event information. For instant, when you view a rod traveling very fast, [quoted text clipped - 3 lines] > photons carrying the true rear position, the front photon must travel the > length of the rod to be synchronized with the rear. Yes, but that has nothing to do with lenght contraction. This only happens when the rod is approaching you. When it is receding from you, it will appear to be longer. In both cases light signals are sent out simultaneously according to some who moves together with the rod. The phonomenon that is called length contraction, does not work this way. With length contraction, the distances to the two ends of the moving rod are to be measured at the same time according to the one who does the measuring. So, when probing the ends, signals must be sent out to the end points at different times, in order to make sure that the reflection events occur simultaneously. When we do that, we find a "measured length" that is shorter than the "proper length", both in the approaching and in the receding case. > The problems I'm having with this classical view of relativity is I do get a > one to one formulas match with the Lorentz transforms. That might be because > I'm not assuming c for all reference frames. Hm, I think it is because your view of relativity is wrong :-) > I argue you can't measure > particles moving faster than the speed of light because of the inherit > propagation delay, but I do not know why all moving inertial reference frame > must measure the same speed of light. There is no *obligation* for these frame to measure the same speed of light. We just assume it. And it seems to work. > They explain this by defining > space-time as a curve, so that Galilean geometry isn't appropriate. No, not at all. That's a completely different story. > My point is the null results of the Michelson-Morley experiment is > insufficient evident to conclude "speed of light is independent of all > moving reference frame". It certainly is sufficient evidence to assume it, and see where it leads us... and it seems to lead us very far, actually :-) If you have a good alternative that also "works", you are free to propose it... Dirk Vdm Hi again, A comment on length contraction explanation. First, I don't mean to plagiarize the www.drphysics.com/syllabus/time/time.html web page... but its enssential in illustrating my point. The graphics attachment cause the original reply not to be posted, so, I'm resending it with the request to look for the illustration at the bottom portion of the page, located at the above web address. Note, the physical of geometry space movement and the mathematic derivation stated below... does not include the latency time of light to travel back to the lab observer. L + v*t1 = c*t1 (= the position expanded by the front of the rocket at time t1. The photon is at that coordinate at t1. But somehow that information is assumed to be instantly back at the observer (a Galilean point of view of time and space). At t =0 the pulse had 0 distance to transverse, but at t1 the pulse had an add distance to transverse. We are summing implicit in measuring a speed -- information of its position is available at that some time. I'm summing that photons carring information to the observer. Relativity enthusiastic brounce back and front on the speed of information transfer. For instant, to show envents do not need to be simultaneous in relativitic reference frames, they assume positional information travels on photons at the speed of light/ Lorentz Contraction This is a derivation of the Lorentz-contraction formula. We will go over the ideas in class, but the algebra is a bit gruesome. So, I'm putting that part here. Refer to Fig. 2. As with the time dilation example, imagine a pulse of light reflects from a mirror back to a receiver. Light will be the "yardstick" used to measure the length of an object in the lab and rocket frames. Some notation: L' = length of stick in the "rocket" L = length of stick in the "lab" t1 = travel time of light pulse to the end of the stick (lab) t2 = travel time of light pulse back from the end of the stick (lab) t = t1+t2 = total travel time in the lab t' = total travel time in the rocket v = speed of rocket in the lab frame In the lab: L + v*t1 = c*t1 L - v*t2 = c*t2 t = t1 + t2 = (2L/c)/(1-v2/c2) In the rocket: 2L' = c*t' t' = 2L'/c We know from the time dilation formula that t' = t*sqrt(1-v2/c2) So, 2L'/c = (2L/c)/sqrt(1-v2/c2) L' = L/sqrt(1-v2/c2) L = L'*sqrt(1-v2/c2) The stick appears shorter in the lab frame since sqrt(1-v2/c2)<1. > Hi again, > > A comment on length contraction explanation. This seems to be the same message as before, only this time without the binary attachment. I already replied to your previous message. Dirk Vdm It was the same comment. But I probably hit "Reply" instead of "Reply Group". I waited several hours and it never apprear as a newsgroup listing. I assumed it was because of the binary attachment. So, I never got your response. King >> Hi again, >> [quoted text clipped - 5 lines] > > Dirk Vdm | Hello, | | I'm not sure how Michelson-Morley conducted their famous experiment, 'nuff said. Androcles. > Hello, > [quoted text clipped - 43 lines] > > King A "reference frame" is a imaginary construct. In scientific fields, no experiment is necessary to show that physicial phenomena are not connected to our imaginations. Sue... | A "reference frame" is a imaginary construct. Nonsense. Cars, buses, trains, aircraft are NOT imaginary constructs, they are very real. | In scientific fields, no experiment is necessary | to show that physicial phenomena are not connected | to our imaginations. So why say that they are? Androcles. > | A "reference frame" is a imaginary construct. > [quoted text clipped - 6 lines] > > So why say that they are? I see what you mean. I just now cycled past a crew of surveyors. I will go back and set them straight about their monuments. Cars, buses, trains, aircraft will be easier to see than wooden stakes anyway. :o) Sue... > Androcles. | > | A "reference frame" is a imaginary construct. | > [quoted text clipped - 13 lines] | Cars, buses, trains, aircraft will be easier to | see than wooden stakes anyway. :o) The reference frame of the monument is more real than the monument, obviously, they've put down stakes to mark where the reference frame is. Thinking of slaying Dracula? You'll need a reference rib. Go back and tell the surveyors their reference frame is not real. They may look at you askance and consider you a dingbat. BTW, did you move relative to your bicycle frame as you cycled past, or did your wider region (the origin of coordinates in the moving frame) remain on that saddle? Androcles. > | > | A "reference frame" is a imaginary construct. > | > [quoted text clipped - 21 lines] > Go back and tell the surveyors their reference frame is not real. > They may look at you askance and consider you a dingbat. They have already surveyed me in that frame because I advised them to drive 100 meter long stakes. Otherwise they will be too short to see when cosmic particles zip past and Lorentz contract them. :o) Sue... > BTW, did you move relative to your bicycle frame as you cycled > past, or did your wider region (the origin of coordinates in the moving > frame) remain on that saddle? > Androcles. | > | > | A "reference frame" is a imaginary construct. | > | > [quoted text clipped - 28 lines] | | Sue... Not a problem, the cosmic particles will see Nelson's column and the Washington Monument at greater than normal length. Androcles. | > BTW, did you move relative to your bicycle frame as you cycled | > past, or did your wider region (the origin of coordinates in the moving | > frame) remain on that saddle? | > Androcles. > A "reference frame" is a imaginary construct. > In scientific fields, no experiment is necessary > to show that physicial phenomena are not connected > to our imaginations. > > Sue... Reference frames give real physical meaning to the explanation of events/phenomena's in time and space, which are real parameters. So reference frames are a real concept for communicating of real construct. Them are not abstract. Because they are not a real object and contrived in our imaginations, do not meaning they have not physical meaning. They can be represented in time and space. > > A "reference frame" is a imaginary construct. > > In scientific fields, no experiment is necessary [quoted text clipped - 9 lines] > our imaginations, do not meaning they have not physical meaning. They can be > represented in time and space. Nature seems to have done fine before we invented 'reference frames' but I know as well as anyone how easy to become dependant on modern conveniences so I'll won't argue that they are not now essential to the conduct of physical phenomena. They must be sort of like gasoline. People now become motionless without it. Sue... > A "reference frame" is a imaginary construct. > In scientific fields, no experiment is necessary > to show that physicial phenomena are not connected > to our imaginations. > > Sue... Reference frames give real physical meaning to the explanation of events/phenomena's in time and space, which are real parameters. So reference frames are a real concept for communicating of real construct. Them are not abstract. Because they are not a real object and contrived in our imaginations, do not meaning they have not physical meaning. They can be represented in time and space. From: http://www.scieng.flinders.edu.au/cpes/people/cahill_r/processphysics.html The Michelson and Morley 1887 Experiment and the Discovery of Absolute Motion Published: Progress in Physics, 3, 25-29, 2005. Abstract: Physics textbooks assert that in the famous interferometer 1887 experiment to detect absolute motion Michelson and Morley saw no rotation-induced fringe shifts - the signature of absolute motion; it was a null experiment. However this is incorrect. Their published data revealed to them the expected fringe shifts, but that data gave a speed of some 8km/s using a Newtonian theory for the calibration of the interferometer, and so was rejected by them solely because it was less than the 30km/s orbital speed of the earth. A 2002 post relativistic-effects analysis for the operation of the device however gives a different calibration leading to a speed > 300km/s. So this experiment detected both absolute motion and the breakdown of Newtonian physics. So far another six experiments have confirmed this first detection of absolute motion in 1887. Electronic copy of paper at: http://www.scieng.flinders.edu.au/cpes/people/cahill_r/CahillMM.pdf > From: > http://www.scieng.flinders.edu.au/cpes/people/cahill_r/processphysics.html [quoted text clipped - 19 lines] > Electronic copy of paper at: > http://www.scieng.flinders.edu.au/cpes/people/cahill_r/CahillMM.pdf Ahem... http://www.scieng.flinders.edu.au/cpes/people/cahill_r/Steene.pdf | "Flinders University theoretical physicist Reg Cahill has | turned the scientific world on its ear by claiming he has | found science's Holy Grail - the fabled Theory of | Everything." http://www.scieng.flinders.edu.au/cpes/people/cahill_r/processphysics... | "A new paradigm for the modelling of reality is | currently being developed called Process Physics. | In Process Physics we start from the premise that | the limits to logic, which are implied by Gödel's | incompleteness theorems, mean that any attempt to | model reality via a formal system is doomed to failure. | Instead of formal systems we use a process system, | which uses the notions of self-referential noise and | self-organised criticality to create a new type of | information-theoretic system that is realising both the | current formal physical modelling of reality but is also | exhibiting features such as the direction of time, the | present moment effect and quantum state entanglement | (including EPR effects, nonlocality and contextuality), | as well as the more familiar formalisms of Relativity | and Quantum Mechanics. In particular a theory of | Quantum Gravity has already emerged. | | In short, rather than the static 4-dimensional modelling | of present day (non-process) physics, Process Physics is | providing a dynamic model where space and matter are | seen to emerge from a fundamentally random but self- | organising system. The key insight is that to adequately | model reality we must move on from the traditional non- | process syntactical information modelling to a process | semantic information modelling; such information is | `internally meaningful'. " Dirk Vdm > http://www.scieng.flinders.edu.au/cpes/people/cahill_r/Steene.pdf > | "Flinders University theoretical physicist Reg Cahill has > | turned the scientific world on its ear by claiming he has > | found science's Holy Grail - the fabled Theory of > | Everything." It will be interesting to see if his theory can pass the test of Gravity Probe B :-) ================================ Novel Gravity Probe B Gravitational Wave Detection To be published: Relativity, Gravitation, Cosmology http://www.scieng.flinders.edu.au/cpes/people/cahill_r/HPS23.pdf Abstract: The Gravity Probe B (GP-B) satellite experiment will measure the precession of on-board gyroscopes to extraordinary accuracy. Such precessions are predicted by General Relativity (GR), and one component of this precession is the frame-dragging or Lense-Thirring effect, which is caused by the rotation of the earth, and the other is the geodetic effect. A new theory of gravity predicts, however, a second and much larger frame-dragging or vorticity induced spin precession. This spin precession component will also display the effects of novel gravitational waves which are predicted by the new theory of gravity, and which have already been seen in several experiments. The magnitude and signature of these gravitational wave induced spin precession effects is given for comparison with the GP-B experimental data. [snip 24 lines of utter crap] Observation: http://www.britastro.org/vss/gifc/00918-ck.gif Explanation: http://www.ebicom.net/~rsf1/sekerin.htm (fig 3) (Or stars explode twice in three months). NO f.cking aether, stooopid. Androcles. Dear King Coffee: ... > My point is the null results of the Michelson-Morley > experiment is insufficient evident to conclude "speed > of light is independent of all moving reference frame". Right. It only shows that the aether is undetectable to propagating light in different directions, with different relative path speeds, near the surface of the Earth. This leaves dragged aether (which is obviated by other experimental results), the Lorentz aether, or no aether. You cannot differentiate between the last two. David A. Smith > I'm not sure how Michelson-Morley conducted their famous experiment, That is unconscionable, if you want to discuss it. The AIP has generously made their original paper freely available: http://www.aip.org/history/gap/PDF/michelson.pdf > but to > me they shown that aether (the medium which carries light) has a velocity of > zero (no aether winds in free space). The conclusion that soon follow: the > speed of light is independent of all moving reference frame seam ad hoc > reasoning. This depends in gory detail on what you mean by "aether", and what properties you attribute to it. Note that the MMX alone is not sufficient to rule out all aether theories, but the collection of experiments known today does so, except for esoteric theories that are either indistinguishable from SR or "live in the erorbars" of the experiments (which is exceedingly difficult, and nobody has ever presented a theory that does this). > [...] > My point is the null results of the Michelson-Morley experiment is > insufficient evident to conclude "speed of light is independent of all > moving reference frame". Sure. But the full collection of experiments we now today has only been successfully explained by theories in which the speed of light is measured to be c in any and all inertial frames. If you truly want to understand this, you will have to STUDY -- SR is subtle. Do not attempt to "learn" from sound bites on the internet. You have received numerous replies, a few of which are valid but most are not (the cranks outnumber the knowledgeable people around here by a wide margin). Your replies indicate neither you nor they understand SR very well (if at all). It can be difficult for a neophyte to distinguish sense fron nonsense; the only way I know of is that knowldgeable people often reference real physics textbooks, but the idiots and cranks never do. I recommend: Taylor and Wheeler, _Spacetime_Physics_. Tom Roberts tjroberts@lucent.com > sense fron nonsense; the only way I know of is that knowldgeable people > often reference real physics textbooks, but the idiots and cranks never > do. I recommend: > > Taylor and Wheeler, _Spacetime_Physics_. The older edition is better. Bob Kolker I quess what I'm really wandering is if earth is rotation, how come they did not get a Doppler shift ? >> I'm not sure how Michelson-Morley conducted their famous experiment, > [quoted text clipped - 37 lines] > > Tom Roberts tjroberts@lucent.com Dear King Coffee: > I quess what I'm really wandering is if earth is rotation, > how come they did not get a Doppler shift ? Either there is no aether, or the MMX apparatus propagates through the aether just like light (Lorentz aether). David A. Smith > I quess what I'm really wandering is if earth is rotation, how come they did > not get a Doppler shift ? Remember that each individual measurement of the MMX requires only a few tens of nanoseconds (light rays go from source to eyeball). During such a short period of time the apparatus can be considered to be at rest in an inertial frame to exceedingly good accuracy. In that inertial frame, source and receiver are at rest, so there is no Doppler shift. Note also that the earth's rotation imparts a velocity on the source, mirrors, and detector that is essentially tangential relative to that inertial frame mentioned above (which includes the tangential motion of the apparatus but not its tiny rotation), and such motion has no effect on the image. Tom Roberts tjroberts@lucent.com > Note also that the earth's rotation imparts a velocity on the source, > mirrors, and detector that is essentially tangential relative to that > inertial frame mentioned above (which includes the tangential motion of > the apparatus but not its tiny rotation), and such motion has no effect > on the image. Sorry about the confusing wording there -- I used "tangential" in two COMPLETELY different ways. The first "tangential" meant the motion of the source, mirrors, and detector in that inertial frame is tangential to the propagation of the light rays. The rays are horizontal, and the motions of those things are all essentially vertical. The second "tangential" (in the parenthetical) meant the tangential velocity of the laboratory as it rotates around the earth's center. Tom Roberts tjroberts@lucent.com In the MMX, the mirrors were arranged perpendicular and they were looking for interferences in the two paths. So, timing may not be an issue. I don't claim to know the details of the MMX... but I do know, relative motion between source and detector will produce a Doppler shift in wavelength. That's how they determine the direction and speed of stars and galaxies moving toward or away from Earth. I bet you -- you would see a Doppler shift in wavelength if you compare the light spectrum of the sun between sun raise and sun set. >> I guess what I'm really wandering is if earth is rotation, how come they >> did not get a Doppler shift ? [quoted text clipped - 12 lines] > > Tom Roberts tjroberts@lucent.com > I quess what I'm really wandering is if earth is rotation, how come they did > not get a Doppler shift ? [quoted text clipped - 9 lines] > >> soon follow: the speed of light is independent of all moving reference > >> frame seam ad hoc reasoning. A little precision: that conclusion would have been wrong, and Sagnac showed that clearly with his experiment, as well as Michelson-Gale later. It's only valid for the special case of straight line motion. Harald > > This depends in gory detail on what you mean by "aether", and what > > properties you attribute to it. Note that the MMX alone is not sufficient [quoted text clipped - 26 lines] > > > > Tom Roberts tjroberts@lucent.com King Coffee: >Hello, > [quoted text clipped - 3 lines] >speed of light is independent of all moving reference frame seam ad hoc >reasoning. And? Even if the idea came from tarot cards, the fact that it works is good enough. [...] >I'm not assuming c for all reference frames. I argue you can't measure >particles moving faster than the speed of light because of the inherit >propagation delay, Why would any propagation delay be ``inherent'' unless it was because the speed of light is constant? >but I do not know why all moving inertial reference frame >must measure the same speed of light. They explain this by defining [quoted text clipped - 3 lines] >insufficient evident to conclude "speed of light is independent of all >moving reference frame". Right. The other nails in the ether coffin are, (1) relativity makes more sense, than the alternatives (2) relativity enabled rapid progress in explaining lots of other physics, while the alternatives are being promoted by people who are still trying to explain the physics known before 1900, (3) physicists who actually have to calculate things and understand the physics that goes into the calculations don't really care if relativity makes sense to those who haven't ever tried to use the alternatives to calculate something of interest to physics in this century. If you could show me how to derive the electron to muon to tau mass ratio, which no one knows how to do from scratch, that would be one way to generate some interest. |
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