A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: Peter Webb on 23 Feb 2010 23:20 "mpc755" <mpc755(a)gmail.com> wrote in message news:5d46b213-167c-46a8-9206-cdbefe14ce2c(a)a18g2000yqc.googlegroups.com... On Feb 23, 10:21 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > This is not how it works in AD. Everything in AD is with respect to > the aether. When the clocks are moved to A' and B' they are not > synchronized with respect to each other. > > ___________________________ > How do you work out your speed "relative to the ether"? What makes you > think > it exists at all? What you can determine is your state, or approximate state, with respect to the aether. _________________________________ How, exactly? How can you work out your speed relative to the ether?
From: mpc755 on 23 Feb 2010 23:33 On Feb 23, 11:18 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > "mpc755" <mpc...(a)gmail.com> wrote in message > > news:3d071cf9-0885-44d9-a3b0-2ebc4338fb16(a)d27g2000yqf.googlegroups.com... > On Feb 23, 10:21 pm, "Peter Webb" > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > This is not how it works in AD. Everything in AD is with respect to > > the aether. When the clocks are moved to A' and B' they are not > > synchronized with respect to each other. > > > ___________________________ > > How do you work out your speed "relative to the ether"? What makes you > > think > > it exists at all? > > I have explained this to you at least 10 times. If you want to know > how it works out with respect to the aether read the posts I have > already posted in response to this question. > > __________________________________ > You haven't outlined an experiment which would show your speed "relative to > the ether". I suggested one - you measure the speed of light in your local > reference frame, For the 22nd time, the speed will be measured as 'c' in the local reference frame. > subtract it from 'c', and this gives you your speed > relative to the ether. You said this wouldn't work because the speed of > light will always be measured at 'c', so this will always show you are at > rest with respect to the ether. > > So, please outline an experiment which would tell you your speed relative to > the ether as being anything other than zero.
From: Bruce Richmond on 23 Feb 2010 23:38 On Feb 23, 9:50 pm, "J. Clarke" <jclarke.use...(a)cox.net> wrote: > On 2/23/2010 8:36 PM, Bruce Richmond wrote: > > > > > > > On Feb 21, 11:52 pm, "J. Clarke"<jclarke.use...(a)cox.net> wrote: > >> 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. > > > Hold that prize. The discussion was about the basis of SR. I > > consider the second postulate to be a basic concept that SR was > > founded on. I was informed by some of the experts here that my > > thinking was outdated. > > You'll find some physicists who put mathematical formalisms over > physical insight--the constancy of the velocity of light was one of > Einstein's two basic postulates and special relativity can be derived > using those postulates. That it can be derived in other ways doesn't > alter that basic insight. The reason I asked Mark's opinion was because of what he wrote just above my "Thank you". "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." The experts here have said that the second postulate could be violated without disproving SR. Considering your statement above about throwing SR out the window I would say you agree with me that they are wrong about that. In SR the second postulate reads "light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body." That is it travels at some constant speed in such a way that no ray of light could overtake another ray. Remember, I mentioned this exchange took place in the DeSitter thread. It was DeSitter that argued against the ballistic theory of light, as promoted by Ritz http://www.datasync.com/~rsf1/crit/1908a.htm In ballistic theory light can travel at c+v which would allow one ray to overtake another. That would mean there is no single "speed of light". > The thing is, either relativity is a usefully accurate description of > reality or it isn't. If it isn't then someone should be able to conduct > an experiment that is inconsistent with relativity and show that it is > invalid. So far many experiments have been performed and none have > succeeded in showing it to be invalid. > > >>> 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. > > > I am well aware that the speed of light is c by definition in SR. > > No, c is the speed of light, period. This has nothing to do with > special relativity or general relativity or Newtonian mechanics or > anything else. The physics community has chosen to write "c" instead of > spelling out "the speed of light, whatever that might be". You're > reading too much into it. It's just a shorthand. In SR the second postulate reads "light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body." That is it travels at some constant speed in such a way that no ray of light could overtake another ray. Remember, I mentioned this exchange took place in the DeSitter thread. It was DeSitter that argued against the ballistic theory of light, as promoted by Ritz http://www.datasync.com/~rsf1/crit/1908a.htm In ballistic theory light can travel at c+v which would allow one ray to overtake another. That would mean there is no single "speed of light". So it is a convention of SR, and ether theory, that c is the speed of light. That is why I included the qualifier "in SR". > > That is basicly what I said in the paragraph above that starts with > > "Thank you". Again the experts told me I was wrong, that the speed of > > light was the distance traveled divided by the time. > > So what else would be, the color of apples divided by the temperature of > a polar bear's nose? If you defined c as the speed of light then the distance is derived from c, not c from the distance. In effect the distance is ct. If you now measure how long it takes light to travel that distance you had better get t or you have proven that the speed of light isn't constant. > c is the velocity of light. By definition. That velocity has some > measurable numerical value, you measure the time it takes light to > travel a given distance and you have an approximation of the numerical > value of c. You measure again with an improved apparatus and you have a > more accurate approximation. The fact that the two approximations are > different has no bearing on calling the velocity of light "c". When I pointed out that in SR the speed of light is c by definition due to the second postulate I was told by the "experts" that I was wrong. > Maybe is has more than one value, maybe it has two or three or a > billion--so far though it seems to have just one. If it has more than one value then it is not a constant and SR just got flushed down the tubes. > >>> 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". > > > What's so hard to understand? They said the second postulate doesn't > > matter any more, so I told them they could be talking about SR. > > Well then you created more confusion than you cured.- Hide quoted text - > > - Show quoted text -
From: mpc755 on 23 Feb 2010 23:40 On Feb 23, 11:20 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > "mpc755" <mpc...(a)gmail.com> wrote in message > > news:5d46b213-167c-46a8-9206-cdbefe14ce2c(a)a18g2000yqc.googlegroups.com... > On Feb 23, 10:21 pm, "Peter Webb" > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > This is not how it works in AD. Everything in AD is with respect to > > the aether. When the clocks are moved to A' and B' they are not > > synchronized with respect to each other. > > > ___________________________ > > How do you work out your speed "relative to the ether"? What makes you > > think > > it exists at all? > > What you can determine is your state, or approximate state, with > respect to the aether. > > _________________________________ > How, exactly? How can you work out your speed relative to the ether? The speed of one reference frame with respect to the aether can be determined relative to another reference frame. Atomic clocks 'tick' based on the aether pressure in which it exists. An objects momentum determines the aether pressure on and through the object. The greater the momentum the greater the associated aether pressure. The speed of a GPS satellite with respect to the aether causes it to displace more aether and for that aether to exert more pressure on the clock in the GPS satellite than the aether pressure associated with a clock at rest with respect to the Earth. This causes the GPS satellite clock to "result in a delay of about 7 ìs/day".
From: Bruce Richmond on 24 Feb 2010 00:11
On Feb 23, 10:08 pm, mpc755 <mpc...(a)gmail.com> wrote: > On Feb 23, 9:44 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > > > On Feb 21, 8:06 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Feb 21, 12:25 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > On Feb 21, 11:34 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > 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'. > > > > > > What you fail to be able to understand is the rate at which a clock > > > > > 'ticks' is based upon the aether pressure in which it exists. For > > > > > example, we have a clock on the embankment and a clock on a train and > > > > > both the train and the embankment exist in the same three dimensional > > > > > space. Since the state of the aether is determined by its connections > > > > > with the matter the state of the aether is that it can be considered > > > > > to be at rest with respect to the embankment. Since the train is > > > > > moving relative to the embankment the train is not at rest with > > > > > respect to the train. The clocks on the train will 'tick' slower than > > > > > the clocks on the embankment. > > > > > > This nonsense of the Observer on the train seeing the clock on the > > > > > embankment 'tick' slower and the Observer on the embankment seeing the > > > > > clock on the train 'tick' slower is exactly that, complete nonsense. > > > > > You have progressed a long way from where you were. It's time to take > > > > another step. From you previous posts I see you agree that the clocks > > > > on the train are out of sync with the clocks on the embankment. Now > > > > consider how the train observers measure the tick rate of a clock on > > > > the embankment. Viewed from the train the clock at A on the > > > > embankment passes along the length of the train. No single train > > > > observer can deterimine the tick rate of A because he only sees A for > > > > one instant. So the tick rate at A is determined by having multiple > > > > observers record the reading on clock A and the time of that reading > > > > *according to their own clock*. > > > > > The clocks at A and A' are compared when they pass and the difference > > > > in their readings noted. Next the clocks at A and B' are compared and > > > > their difference in reading noted. If that difference has increased > > > > the train observers must conclude that the clock at A is running slow > > > > because it has lost time compared to the clock at B' *which is in sync > > > > with the clock at A'*. > > > > > The track observers see what the train observers are doing and realize > > > > the train observers got a different result because *the clocks at A' > > > > and B' are out of sync*. > > > > > So now maybe you can see that the train observers can *measure* the > > > > tick rate of the embankment clocks to be slower, even if it is in fact > > > > faster. > > > > > Bruce > > > > When the clocks are moved on the train they wind up at A' and B' and > > > read 12:00:01 and 12:00:00, respectively. Since the embankment is at > > > rest with respect to the aether when the clocks are moved to A and B > > > they both read 12:00:00. > > > > If the train is moving fast enough the clocks on the train should be > > > ticking slow enough that the difference in the times at A' and B' > > > should be outweighed by the slowness of the ticking. For example, > > > let's say B' and A are co-located at 12:00:00. It takes 3 seconds, as > > > determined by the clock at B', to go from A to B. It takes 5 seconds > > > as determined by the clock at A to go from B' to A'. When B' and B are > > > co-located their clocks will read 12:00:03 and 12:00:05, respectively.. > > > When A' and A are co-located their clocks will read 12:00:04 and > > > 12:00:05, respectively. All of the Observers conclude the clocks on > > > the train 'tick' slower than the clocks on the embankment. > > > There is no "fast enough" here. RoS works whenever there is a > > relative speed between frames. > > But what is different between AD and RoS is the unsynchronization of > the clocks. In RoS it doesn't matter how the train is moving relative > to the aether, the clocks when moved to A' and B' will still be > synchronized with respect to each other and with respect to the train. > This is not how it works in AD. Everything in AD is with respect to > the aether. When the clocks are moved to A' and B' they are not > synchronized with respect to each other. Einstein never said there is no ether, just that SR doesn't need to consider it. So to explain this to you I will invoke an ether at rest WRT the tracks. If A and B make note of when B' passes them, and what the B' clock displayed for a time, they can calculate that the B' clock is ticking slower than their own clocks. Note that there is no direct comparison of the tick rates. The difference is determined by calculation, and that calculation assumes that the clocks at A and B display the same time. If you observer from the track frame the transport of clocks from M' to A' and B' you will see the clocks changing sync as they are transported. Slow transport of clocks results in the same sync as the using light signals, which we know will be viewed from the tracks as being out of sync. So your AD clocks are behaving the same as SR clocks. > > As for the slowness of the ticking > > outweighing clock sync, you are just waving your arms. The two things > > you time above tell you nothing about the tick rate of the clocks. > > They aren't measuring the same thing. You wrote "It takes 3 seconds, > > as determined by the clock at B', to go from A to B." What you need > > to compare that to is the time for B' to go from A to B, as determined > > by the clocks at A and B. That is where the clock sync comes in to > > play. > > If the train is moving fast enough the clocks on the train will be > 'ticking' slow enough that when the Observers on the train at A' and > B' get back together and discuss what time the clock at A said when > they both saw it it will have increased more in time than the clock at > A' does even after including its unsynchronizaion.- Hide quoted text - Stop waving your arms and type some numbers. SR and LET tell us exactly how the clocks relate to each other. If AD is a real theory you should be able to tell me how to calculate exactly how fast the train clock runs. You should also be able to tell me exactly how the lenght of the moving train compares to its length when stopped. |