Why physicists refuse to measure the one-way speed of light directly?
in [Relativity]
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From: kenseto on 15 Jan 2010 08:52 On Jan 14, 7:49 pm, "Inertial" <relativ...(a)rest.com> wrote: > "eric gisse" <jowr.pi.nos...(a)gmail.com> wrote in message > > news:hiob58$l5k$2(a)news.eternal-september.org... > > > > > > > ..@..(Henry Wilson DSc) wrote: > > > [...] > > >> For instance, if a moving source (MS) OWLS experiment was to be carried > >> out over 3000 metres the travel time would be around 10^-5 seconds. If > >> the > >> source were subsequently made to move at 30 m/s, the travel time would > >> change by only 1 part in 10^7...so the travel time has to be measured to > >> considerably better that 1 part in 10^12 to be meaningful. > >> Since this type of experiment involves TWO synched clocks, this is asking > >> quite a lot. > > > Its' been done, a fact that you are clearly unaware. > > > Such precision is easily attainable, and you gave a really slow source > > velocity. That you aren't interested in the literature simply means you > > don't care about science. > > > [snip rest] > > Of course, what Henry doesn't understand (apart from most of physics), is > that one doesn't need OWLS to refute ballistic theories. For example, we > know experimentally that (two-way) light speed is constant despite velocity > of moving sources .. ie there is no c+v .. whereas ballistic theories says > that it will not be. If there is no c+v then why did Einstein said that M' is rush toward the light from the front of the train (c+v). - Hide quoted text - > > - Show quoted text -
From: Inertial on 15 Jan 2010 09:13 "kenseto" <kenseto(a)erinet.com> wrote in message news:33b307b5-1d6c-4c43-8733-40bb9728b4dc(a)m3g2000yqf.googlegroups.com... > On Jan 14, 7:49 pm, "Inertial" <relativ...(a)rest.com> wrote: >> "eric gisse" <jowr.pi.nos...(a)gmail.com> wrote in message >> >> news:hiob58$l5k$2(a)news.eternal-september.org... >> >> >> >> >> >> > ..@..(Henry Wilson DSc) wrote: >> >> > [...] >> >> >> For instance, if a moving source (MS) OWLS experiment was to be >> >> carried >> >> out over 3000 metres the travel time would be around 10^-5 seconds. If >> >> the >> >> source were subsequently made to move at 30 m/s, the travel time would >> >> change by only 1 part in 10^7...so the travel time has to be measured >> >> to >> >> considerably better that 1 part in 10^12 to be meaningful. >> >> Since this type of experiment involves TWO synched clocks, this is >> >> asking >> >> quite a lot. >> >> > Its' been done, a fact that you are clearly unaware. >> >> > Such precision is easily attainable, and you gave a really slow source >> > velocity. That you aren't interested in the literature simply means you >> > don't care about science. >> >> > [snip rest] >> >> Of course, what Henry doesn't understand (apart from most of physics), is >> that one doesn't need OWLS to refute ballistic theories. For example, we >> know experimentally that (two-way) light speed is constant despite >> velocity >> of moving sources .. ie there is no c+v .. whereas ballistic theories >> says >> that it will not be. > > If there is no c+v then why did Einstein said that M' is rush toward > the light from the front of the train (c+v). Because he knew you'd have no hope of understanding him. Just as you'd have no hope of understanding if I explained it to you
From: Inertial on 15 Jan 2010 09:23 "kenseto" <kenseto(a)erinet.com> wrote in message news:1cf0a2f6-10dc-4a59-b388-62edc742f18d(a)o28g2000yqh.googlegroups.com... > On Jan 14, 6:11 pm, ..@..(Henry Wilson DSc) wrote: >> On Mon, 11 Jan 2010 05:59:13 -0800 (PST), kenseto <kens...(a)erinet.com> >> wrote: >> >Why physicists refuse to measure the one-way speed of light directly? >> >The answer: >> >The one-way speed of light is physical distance dependent. >> >BTW that's why they invented a new definition for a meter length: 1 >> >meter=1/299,792,458 light second >> >Using this definition the one-way speed of light is c by definition. >> >> >Ken Seto >> >> Why all the confusion? >> >> 'c' is a universal constant with dimensions L/T >> As far as we know it is also the speed of EM wrt its source. > > Sigh....the point is that the value of the speed of light never been > measured directly (one-way or two-ways)..... Wrong .. its been measured many times > in the expression of L/T > the L never been measured physically with a physical ruler in two-way > experiments..... nonsense > they use light speed to measure the distance L. Nope > What > this mean is that the SRians' claim that the value of twls is a > universal constant c is a false claim. No .. its a claim supported by epxeriment > In any correct ether theory the value of twls is physical distance > dependent. No .. its not. It is always the same speed relative to the aether >> The task before us is to measure the OW speed of EM....more to the point >> is to >> measure it using a source that moves relative to the observer. OWLS >> isotropy >> experiments invariably test for the existence of an absolute aether. > > Sigh....the owls from a moving sodium source is measured as follows: > c'=(detected incoming frequency of sodium light)(universal wavelength > of sodium 589 nm) Wavelength is frame dependant You're wrong on all accounts .. not surprising
From: Da Do Ron Ron on 15 Jan 2010 13:53 PD gave it his best shot, as follows: >It's simpler than a physical process. >Einstein's synchronization procedure requires some signal >that is guaranteed to go at the same speed in either direction. >The procedure is this: >1. Note the time t1 at clock A. >2. Send a signal from clock A to clock B at a speed v. You should have asked Tom for help, PD. Your mistake is at step 2. You cannot measure any speed (including v) until you first synchronize the clocks. Therefore, you cannot be sure that anything, including both a walking person and a light ray, will be moving at the same speed (wrt the clocks) in both directions. Einstein put is thusly: Your definition would certainly be right, if I only knew that the light by means of which the observer at M perceives the lightning flashes travels along the length A > M with the same velocity as along the length B > M. But an examination of this supposition would only be possible if we already had at our disposal the means of measuring time. It would thus appear as though we were moving here in a logical circle. http://www.bartleby.com/173/8.html Do you see why Einstein called it a "logical circle"? Your method given above obscures the truth because it is not direct. That is, it does not present Einstein's definition explicitly enough. But my following method (the one I already gave) does. Frame A [0]---------x----------[?] Source S~~>light [0]---------x----------[?] -->v Frame B In order to fully grasp Einstein's definition of clock synchronization, you need to fill in the blanks (i.e., the [?]). Note that this method pertains to invariance because it has two frames. (Yours did not.) That is, what times must be placed on the right-hand clock faces prior to the release of the light from S? ~~RA~~
From: PD on 15 Jan 2010 14:23
On Jan 15, 12:53 pm, Da Do Ron Ron <ron_ai...(a)hotmail.com> wrote: > PD gave it his best shot, as follows: > > >It's simpler than a physical process. > >Einstein's synchronization procedure requires some signal > >that is guaranteed to go at the same speed in either direction. > >The procedure is this: > >1. Note the time t1 at clock A. > >2. Send a signal from clock A to clock B at a speed v. > > You should have asked Tom for help, PD. > Your mistake is at step 2. > You cannot measure any speed (including v) until you > first synchronize the clocks. That's the point, and why Tom makes the guarantee he does. > Therefore, you cannot be sure that anything, including > both a walking person and a light ray, will be moving > at the same speed (wrt the clocks) in both directions. > > Einstein put is thusly: > Your definition would certainly be right, if I only knew that the > light by means of which the observer at M perceives the lightning > flashes travels along the length A > M with the same velocity as > along the length B > M. But an examination of this supposition would > only be possible if we already had at our disposal the means of > measuring time. It would thus appear as though we were moving here in > a logical circle.http://www.bartleby.com/173/8.html > > Do you see why Einstein called it a "logical circle"? Yes, indeed. > > Your method given above obscures the truth because it is not direct. It is nevertheless the method that Einstein proposed. But fortunately, we don't have to measure v to arrive at a number. All we have to do is to assure isotropy, and neither of these requires either a TWLS or OWLS measurement. Note that synchronization is inherently a statements about clocks that are at rest relative to each other, and so there is no need for multiple frames, and in fact a multiple frame scenario is discouraged. > That is, it does not present Einstein's definition explicitly enough. > But my following method (the one I already gave) does. > > Frame A > [0]---------x----------[?] > Source S~~>light > [0]---------x----------[?] -->v > Frame B > > In order to fully grasp Einstein's definition of clock > synchronization, you > need to fill in the blanks (i.e., the [?]). > > Note that this method pertains to invariance because it has two > frames. > (Yours did not.) > > That is, what times must be placed on the right-hand clock faces prior > to > the release of the light from S? > > ~~RA~~ |