Why physicists refuse to measure the one-way speed of light directly?
in [Physics]
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From: kenseto on 23 Jan 2010 09:09 On Jan 22, 4:37 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Jan 22, 1:41 pm, Da Do Ron Ron <ron_ai...(a)hotmail.com> wrote: > > > > > > > T Roberts asked: > > > >I have no idea what you mean. The propagation of light just occurs > > >however it happens, and clocks are simply synchronized according to > > >some prescribed method. > > >What "physical process" do you mean? > > > It is the process that you mentioned just prior to your query, namely, > > the > > "prescribed method" of clock synchronization; however, since you have > > not yet properly applied this method to more than one frame, you > > cannot > > fully understand it. > > > Yes, I know that you believe that you have done this, because you > > said > > the following: > > > >As no mention of which inertial frame was used, this applies in any > > >inertial frame, thus ensuring invariance of the one-way speed of light.. > > > But this is wrong, as my prior (simple) diagram should have shown. > > As I have tried to get you to see, merely repeating the same frame > > over and over (as you just did, and as the Einsteinian version of his > > method does) does _not_ convey the full story. > > > There is only one way to properly show Einstein's convention of > > synchronization in more than one frame, and that, as I have tried > > to get across, is by letting the frames share the light source. > > > Giving each frame its own source is to merely and uselessly repeat > > the same frame over and over and over. > > > Here, _again_, is a picture of the start of the physical process > > about > > which you asked above: > > > Frame A > > [0]---------x----------[?] > > Source S~~>light > > [0]---------x----------[?] -->v > > Frame B > > > Notice the very careful and very necessary usage of a single light > > source. > > > Notice the equally necessary usage of at least two frames. > > > Since this is NOT done in any relativity text, no one has yet seen > > the > > full version of Einstein's definition of clock synchronization. > > > Therefore, no one has yet seen the full truth re Einstein's > > definition. > > > To repeat, the _ONLY_ way to see the full truth of the definition > > is by carrying the above picture to completion. > > > You, or PD, or Android, or Dirk, or Seto, or Gisse, or _some_ person > > MUST fill in the blanks to complete the diagram. > > Sorry, but no. If you do not understand what Einstein's procedure is, > look at what I wrote to you earlier, where I explained it simply. No > one is obligated to follow YOUR boondoggles, just because you claim > it's what Einstein really meant (which he did not). Einstein's synchronization procedure is circular: The procedure is as follows: 1. Note the time t1 at clock A. 2. Send a signal from clock A to clock B at a speed v. 3. When the signal arrives, note the time t2 at clock B. 4. Send a signal from clock B to clock A at a speed v. 5. When the signal arrives, note the time t3 at clock A. 6. If t3-t2 = t2-t1, then the clocks are synchronized. The clocks A and B must be pre-synchronized to begin with before Einstein's procedure is valid. If you already know the clocks are synchronized why do you need to synchronize them again using Einstein's procedure? Also if you have two spatially separated synchronized clocks why don't you use them to determine the one way speed of light? Ken Seto > > > > > Only then will the > > full physical process of which we are speaking be made perfectly > > clear. > > > Have I made myself perfectly clear? > > > I will even bend over backward to carry the picture one step further: > > > Frame A > > [0]---------x----------[?] > > Source S---------------->light > > ----------[0]---------x----------[?] -->v > > Frame B > > > WHAT, pray tell, is the reading NOW on A's right-hand clock per > > Einstein's definition of clock synchronization? > > > Can anyone tell us? > > > ~~RA~~ > > (as was given, x is the ruler-measured distance > > given a ruler at rest wrt the frame in which the > > measurement is made)- Hide quoted text - > > - Show quoted text -- Hide quoted text - > > - Show quoted text -
From: Sam Wormley on 23 Jan 2010 10:42 On 1/23/10 8:09 AM, kenseto wrote: > Also if you have two spatially separated synchronized clocks why don't > you use them to determine the one way speed of light? > > Ken Seto The speed of light is constant, Seto. We use light speed define distance measure for more than a quarter of a century now. Where have you been!
From: Tom Roberts on 23 Jan 2010 11:05 glird wrote: > On Jan 19, 3:22 pm, PD <thedraperfam...(a)gmail.com> wrote: >> http://edu-observatory.org/physics-faq/Relativity/SR/experiments.html... > > I looked and found this in it: "M�ssbauer experiments show that the > rate of a clock is independent of acceleration (~1016 g) and depends > only upon velocity." Bailey et al extends this to ~ 10^18 g. > How can an acceleration, a = dv/dt, have no affect on something that > varies with v? Experiments show that the INTRINSIC rate of a clock does not depend on its velocity v, up to at least v ~ 0.9999 c; it does not depend on a (= dv/dt), up to at least a ~ 10^18 g. Both are of course measured relative to a locally inertial frame. An inertial observer will MEASURE the rate of a moving clock as slowed down by the gamma factor of SR, but this does not mean the clock ITSELF is affected; indeed the clock itself CANNOT be affected by either v or a in order for the theory to agree with experiments. Some clocks are broken by sufficiently large a. This only applies to clocks that are not broken. Fortunately both atomic transitions and muon decays are highly robust clocks. You REALLY need to learn what SR actually says. Your head is so full of nonsense that you never seem to get anything right. Tom Roberts
From: PD on 23 Jan 2010 15:33 On Jan 23, 8:09 am, kenseto <kens...(a)erinet.com> wrote: > On Jan 22, 4:37 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jan 22, 1:41 pm, Da Do Ron Ron <ron_ai...(a)hotmail.com> wrote: > > > > T Roberts asked: > > > > >I have no idea what you mean. The propagation of light just occurs > > > >however it happens, and clocks are simply synchronized according to > > > >some prescribed method. > > > >What "physical process" do you mean? > > > > It is the process that you mentioned just prior to your query, namely, > > > the > > > "prescribed method" of clock synchronization; however, since you have > > > not yet properly applied this method to more than one frame, you > > > cannot > > > fully understand it. > > > > Yes, I know that you believe that you have done this, because you > > > said > > > the following: > > > > >As no mention of which inertial frame was used, this applies in any > > > >inertial frame, thus ensuring invariance of the one-way speed of light. > > > > But this is wrong, as my prior (simple) diagram should have shown. > > > As I have tried to get you to see, merely repeating the same frame > > > over and over (as you just did, and as the Einsteinian version of his > > > method does) does _not_ convey the full story. > > > > There is only one way to properly show Einstein's convention of > > > synchronization in more than one frame, and that, as I have tried > > > to get across, is by letting the frames share the light source. > > > > Giving each frame its own source is to merely and uselessly repeat > > > the same frame over and over and over. > > > > Here, _again_, is a picture of the start of the physical process > > > about > > > which you asked above: > > > > Frame A > > > [0]---------x----------[?] > > > Source S~~>light > > > [0]---------x----------[?] -->v > > > Frame B > > > > Notice the very careful and very necessary usage of a single light > > > source. > > > > Notice the equally necessary usage of at least two frames. > > > > Since this is NOT done in any relativity text, no one has yet seen > > > the > > > full version of Einstein's definition of clock synchronization. > > > > Therefore, no one has yet seen the full truth re Einstein's > > > definition. > > > > To repeat, the _ONLY_ way to see the full truth of the definition > > > is by carrying the above picture to completion. > > > > You, or PD, or Android, or Dirk, or Seto, or Gisse, or _some_ person > > > MUST fill in the blanks to complete the diagram. > > > Sorry, but no. If you do not understand what Einstein's procedure is, > > look at what I wrote to you earlier, where I explained it simply. No > > one is obligated to follow YOUR boondoggles, just because you claim > > it's what Einstein really meant (which he did not). > > Einstein's synchronization procedure is circular: > The procedure is as follows: > 1. Note the time t1 at clock A. > 2. Send a signal from clock A to clock B at a speed v. > 3. When the signal arrives, note the time t2 at clock B. > 4. Send a signal from clock B to clock A at a speed v. > 5. When the signal arrives, note the time t3 at clock A. > 6. If t3-t2 = t2-t1, then the clocks are synchronized. > > The clocks A and B must be pre-synchronized to begin with before > Einstein's procedure is valid. No, they do not. If step 6 shows an inequality, this indicates the clocks were not synchronized. Suppose that t3-t2 is 38 usec and t2-t1 is 36 usec. Then these two clocks are not synchronized. But the inequality tells you what you have to do to make the correction. Clock B is slow by 1 usec. If you set it back by 1 usec and repeat the procedure, then you will find that t3-t2 is 37 usec and t2-t1 is 37 usec. Now step 6 shows an equality. Congratulations! You have synchronized the clocks. Do you understand now? Has it really taken 12 years for you to have this procedure explained to you in a way that you can understand it? > If you already know the clocks are > synchronized why do you need to synchronize them again using > Einstein's procedure? > Also if you have two spatially separated synchronized clocks why don't > you use them to determine the one way speed of light? Because the resolution and experimental accuracy obtained by using two synchronized clocks does not beat the resolution and experimental accuracy obtained by the combination of TWLS and anisotropy experiments. The reasons have to do with the detailed analysis of sources of experimental uncertainty, which you can only get by reading the full experimental papers and not just the abstracts. > > Ken Seto > > > > > > Only then will the > > > full physical process of which we are speaking be made perfectly > > > clear. > > > > Have I made myself perfectly clear? > > > > I will even bend over backward to carry the picture one step further: > > > > Frame A > > > [0]---------x----------[?] > > > Source S---------------->light > > > ----------[0]---------x----------[?] -->v > > > Frame B > > > > WHAT, pray tell, is the reading NOW on A's right-hand clock per > > > Einstein's definition of clock synchronization? > > > > Can anyone tell us? > > > > ~~RA~~ > > > (as was given, x is the ruler-measured distance > > > given a ruler at rest wrt the frame in which the > > > measurement is made)- Hide quoted text - > > > - Show quoted text -- Hide quoted text - > > > - Show quoted text -
From: eric gisse on 23 Jan 2010 16:22
kenseto wrote: [...] > Also if you have two spatially separated synchronized clocks why don't > you use them to determine the one way speed of light? One way speed of light tests have been done, Ken. Directly, and indirectly through anisotropy measurements of light speed in addition to two way light speed tests. Do you see how limits on anisotropy and knowledge of two way light speed limits one way light speed, or do you need another 15 years to parse the concept? [...] |