A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: mpc755 on 21 Feb 2010 21:06 On Feb 21, 7:01 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > "mpc755" <mpc...(a)gmail.com> wrote in message > > news:45589ff0-5e7f-4a93-b9b0-2f3157708426(a)m37g2000yqf.googlegroups.com... > On Feb 21, 9:18 am, "Peter Webb" > > > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > "mpc755" <mpc...(a)gmail.com> wrote in message > > >news:dba2b7ab-670a-473f-a7f3-5447e3f01e53(a)b7g2000yqd.googlegroups.com... > > On Feb 21, 12:27 am, "Peter Webb" > > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > > "mpc755" <mpc...(a)gmail.com> wrote in message > > > >news:1c9cf786-36cc-4fce-8b57-7f45f5b88ddd(a)v1g2000yqk.googlegroups.com.... > > > On Feb 20, 11:21 pm, "Peter Webb" > > > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > > > > And if conducted in a laboratory in low earth orbit, with a relative > > > > > speed > > > > > of 25,000 kph relative to the ether - what will be the measured > > > > > speed > > > > > of > > > > > light then? > > > > > The light will be 'measured' to be 'c'. If the Observers in the > > > > laboratory in low Earth orbit know how they are moving with respect to > > > > the aether they will be able to determine the speed of light to be 'c' > > > > with respect to the aether. > > > > > ______________________________________ > > > > So, according to you, in every inertial reference frame, the measured > > > > speed > > > > of light is "c", completely independent of how the observer is moving > > > > relative to the ether? > > > > Measured, yes. > > > > ____________________________________ > > > OK, is the speed of light measured as 'c' in every inertial reference > > > frame? > > > Measured, yes. > > > _______________________________ > > How about the rest of the predictions of SR? Will lengths and times > > measure > > according to SR? You have no problem with the 80 foot ladder fitting > > inside > > the 40 foot barn, or the twins "paradox" ? > > I have already explained to you probably twenty times now the atomic > clocks 'tick' based upon the aether pressure in which the exist. There > may be length contraction at speeds near 'c'. > > __________________________________ > You have explained this many times. Mine is a slightly differerent question. > Do you believe the rest of the predictions of SR? Will lengths and times > measure according to SR? You have no problem with the 80 foot ladder fitting > inside the 40 foot barn, or the twins "paradox" ? As far as I know the calculations in terms of time measure according to SR. However, there is no such thing as 'spacetime'. Time is a concept. The rate at which clocks 'tick' is based upon the aether pressure in which it exists. I am not up to speed on Lorentz contraction. In Aether Displacement, the aether 'displaces back' at 'c'. So and object moving at close to 'c' might be length contracted due to the time it takes for the aether to displace back. What I do not agree with in terms of length contraction is its relativity. If the garage is at rest with respect to the aether and the ladder is moving close to 'c' with respect to the aether then if there is length contraction the ladder will fit into the garage as long as it continues to move at close to 'c'. If the ladder is at rest with respect to the aether and the garage is moving close to 'c' with respect to aether then if there is length contraction, or not, the 80 foot ladder will not fit inside the 40 foot, or less, barn. Length contraction, if it exists, is moving with respect to the aether. For the 21st time, the rate at which clocks 'tick' has nothing to do with time. If a twin travels very fast in a space ship then the atomic clock 'ticks' slower due to the increase in the aether pressure associated with the space ship moving with respect to the aether. The atoms in the twin in the space ship are also affected by the increase in aether pressure. If all else is equal the twin on the space ship may return to Earth and they may even look younger, but the same amount of time has passed. But who knows what effect the additional pressure on each and every nuclei in the twin on the space ship will have on the twin? It might cause the twin on the space ship to age faster. The whole point of the twin paradox is time actually slows for the twin in the spaceship. That is incorrect. Time does not change. Time is a concept.
From: Bruce Richmond on 21 Feb 2010 22:24 On Feb 21, 6:10 pm, mpalenik <markpale...(a)gmail.com> wrote: > On Feb 21, 4:57 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > If we were to extrapolate a trend from history, then physics has not > > yet given us a single equation which describes how the universe > > functions. It has given us some rules of thumb and some cumbersome > > approximations. > > This just further illustrates that you don't understand how physics > actually works. The history of physics isn't a series of blunders > that we've thrown out as we get better and better equations, hampered > by our belief in the old equations. Rather, physics at just about > every point in time since the renaissance has been a journey from very > specific to more general rules--criteria by which any new physics must > be constrained. > > For example, Kepler, while not really a physicist per-se, devised > descriptions of the elliptical orbits that planets must follow. > Newton, then, discovered that this is a special case of the > conservation of angular momentum, which is a much more general > principle--however, conservation of angular momentum MUST be able to > reproduce the elliptical orbits of planets, or else it is wrong. > Kepler's rules constrained Newton's theories. > > Special relativity then changed Newton's laws, a bit. The basic > principles, like F = dp/dt remained, but Special relativity says that > space and time must transform differently than they do in Newtonian > mechanics. However, Newtonian mechanics is still a special case of > special relativity--as the speed of an object approaches zero, the > laws begin to reproduce Newton's laws. Newton's laws, in this way, > constrain Special Relativity. Because if it did *NOT* reproduce > Newton's laws at low speeds, it would be wrong. > > General relativity came along and it turns out that special relativity > only works as a limiting case of general relativity, specifically, > when there is no mass or energy present. As the amount of mass and > energy present goes to zero, general relativity reproduces special > relativity. If it could not do this, it would be wrong. > > Any new physics must be able to reproduce the old physics in the > regimes in which it has been tested. Any new theory that cannot do so > is necessarily wrong because it has already been ruled out by > experiment. Thank you for bringing this up and explaining it so well. A few days ago in the DeSitter thread I wrote that in SR the speed of light is made a universal constant by the second postulate. The coordinate systems are constructed based on that fact. Because of that there is no way you can measure the speed of light to be anything but c without making a mistake. I was then informed that the interpertation of SR has been improved upon since 1905 and that what I had written no longer applied. Further, relativity could survive even if it was found that the speed of light wasn't exactly c. To that I responded that if the second postulate no longer applied then they weren't talking about Einstein's SR and should use a different name for the theory they were describing. From there it got into a pissing contest and I left. Care to comment? > There's no way to know whether at some higher energy or smaller > distance than we've observed the laws of physics actually are > different than what we believe. But even so, these new laws must > reduce to the old ones at lower energies and larger distances. And if > there is some new, more fundimental physics at a different scale, > there's always a nobel prize, or at least several publications in it > for anyone who can find this. > > In order to have a new working theory, however, you must be able to 1) > make predictions that differ from those of the old theories and 2) > show that those predictions match either a new experiment or a > previously unexplained experiment.
From: YBM on 21 Feb 2010 22:39 mpc755 a �crit : > On Feb 21, 7:01 pm, "Peter Webb" > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: >> "mpc755" <mpc...(a)gmail.com> wrote in message >> >> news:45589ff0-5e7f-4a93-b9b0-2f3157708426(a)m37g2000yqf.googlegroups.com... >> On Feb 21, 9:18 am, "Peter Webb" >> >> >> >> <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: >>> "mpc755" <mpc...(a)gmail.com> wrote in message >>> news:dba2b7ab-670a-473f-a7f3-5447e3f01e53(a)b7g2000yqd.googlegroups.com... >>> On Feb 21, 12:27 am, "Peter Webb" >>> <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: >>>> "mpc755" <mpc...(a)gmail.com> wrote in message >>>> news:1c9cf786-36cc-4fce-8b57-7f45f5b88ddd(a)v1g2000yqk.googlegroups.com... >>>> On Feb 20, 11:21 pm, "Peter Webb" >>>> <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: >>>>>> And if conducted in a laboratory in low earth orbit, with a relative >>>>>> speed >>>>>> of 25,000 kph relative to the ether - what will be the measured >>>>>> speed >>>>>> of >>>>>> light then? >>>>> The light will be 'measured' to be 'c'. If the Observers in the >>>>> laboratory in low Earth orbit know how they are moving with respect to >>>>> the aether they will be able to determine the speed of light to be 'c' >>>>> with respect to the aether. >>>>> ______________________________________ >>>>> So, according to you, in every inertial reference frame, the measured >>>>> speed >>>>> of light is "c", completely independent of how the observer is moving >>>>> relative to the ether? >>>> Measured, yes. >>>> ____________________________________ >>>> OK, is the speed of light measured as 'c' in every inertial reference >>>> frame? >>> Measured, yes. >>> _______________________________ >>> How about the rest of the predictions of SR? Will lengths and times >>> measure >>> according to SR? You have no problem with the 80 foot ladder fitting >>> inside >>> the 40 foot barn, or the twins "paradox" ? >> I have already explained to you probably twenty times now the atomic >> clocks 'tick' based upon the aether pressure in which the exist. There >> may be length contraction at speeds near 'c'. >> >> __________________________________ >> You have explained this many times. Mine is a slightly differerent question. >> Do you believe the rest of the predictions of SR? Will lengths and times >> measure according to SR? You have no problem with the 80 foot ladder fitting >> inside the 40 foot barn, or the twins "paradox" ? > > As far as I know You know nothing, you're just a piece of dirt.
From: J. Clarke on 21 Feb 2010 23:52 On 2/21/2010 10:24 PM, Bruce Richmond wrote: > On Feb 21, 6:10 pm, mpalenik<markpale...(a)gmail.com> wrote: >> On Feb 21, 4:57 pm, Ste<ste_ro...(a)hotmail.com> wrote: >> >> >> >>> If we were to extrapolate a trend from history, then physics has not >>> yet given us a single equation which describes how the universe >>> functions. It has given us some rules of thumb and some cumbersome >>> approximations. >> >> This just further illustrates that you don't understand how physics >> actually works. The history of physics isn't a series of blunders >> that we've thrown out as we get better and better equations, hampered >> by our belief in the old equations. Rather, physics at just about >> every point in time since the renaissance has been a journey from very >> specific to more general rules--criteria by which any new physics must >> be constrained. >> >> For example, Kepler, while not really a physicist per-se, devised >> descriptions of the elliptical orbits that planets must follow. >> Newton, then, discovered that this is a special case of the >> conservation of angular momentum, which is a much more general >> principle--however, conservation of angular momentum MUST be able to >> reproduce the elliptical orbits of planets, or else it is wrong. >> Kepler's rules constrained Newton's theories. >> >> Special relativity then changed Newton's laws, a bit. The basic >> principles, like F = dp/dt remained, but Special relativity says that >> space and time must transform differently than they do in Newtonian >> mechanics. However, Newtonian mechanics is still a special case of >> special relativity--as the speed of an object approaches zero, the >> laws begin to reproduce Newton's laws. Newton's laws, in this way, >> constrain Special Relativity. Because if it did *NOT* reproduce >> Newton's laws at low speeds, it would be wrong. >> >> General relativity came along and it turns out that special relativity >> only works as a limiting case of general relativity, specifically, >> when there is no mass or energy present. As the amount of mass and >> energy present goes to zero, general relativity reproduces special >> relativity. If it could not do this, it would be wrong. >> >> Any new physics must be able to reproduce the old physics in the >> regimes in which it has been tested. Any new theory that cannot do so >> is necessarily wrong because it has already been ruled out by >> experiment. > > Thank you for bringing this up and explaining it so well. A few days > ago in the DeSitter thread I wrote that in SR the speed of light is > made a universal constant by the second postulate. The coordinate > systems are constructed based on that fact. Because of that there is > no way you can measure the speed of light to be anything but c without > making a mistake. What point are you trying to support with that statement? If one _measures_ a velocity of light other than the one that it is commonly held to have and others replicate your result, and it is found that light has different velocities under different circumstances then it is not the measurement that is a mistake but you will have just thrown relativity right out the window and they'll be seeing you in Stockholm pretty soon. > I was then informed that the interpertation of SR > has been improved upon since 1905 and that what I had written no > longer applied. Further, relativity could survive even if it was > found that the speed of light wasn't exactly c. Uh, by definition the velocity of light is exactly c. Grok the concept--c is defined as "the velocity of light". Relativity makes no statement concerning a specific value that c must have, only that it is the same in all reference frames. It can be 2 millimeters per millennium or forty quintillion kilometers per femtosecond and relativity remains valid, as long as it demonstrably has that value and only that value, within the limits of experimental error. > To that I responded > that if the second postulate no longer applied then they weren't > talking about Einstein's SR and should use a different name for the > theory they were describing. From there it got into a pissing contest > and I left. Care to comment? You're using phrasing that can easily lead to misunderstanding. Rather than saying "if light has a velocity other than c", try saying "if it can be shown that the velocity of light is different in different reference frames", or "the velocity of light in vacuum is shown under some circumstances to be significantly different from that which has been measured for it in numerous experiments in the past". <snip>
From: Simple Simon on 22 Feb 2010 07:40
PD wrote: > On Feb 18, 9:56 am, "Simple Simon" <pi.r.cubed-nos...(a)gmail.com> > wrote: >> PD wrote: >> >>> The rest length of the rod is unchanged. Since this rest length is >>> the length measured in only one frame (the rest frame), I'm >>> reticent to call it an intrinsic property. >> >> Of two rods, the one with the greater rest length is "larger". Or, >> iif you prefer, the set of possible lengths of the rod with greater >> rest length is greater (and its supremum is its rest length). > > I like this operational definition. You sir, are a gentleman and a scholar. |