Why physicists refuse to measure the one-way speed of light directly?
in [Physics]
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From: kenseto on 12 Jan 2010 12:35 On Jan 11, 5:29 pm, Tom Roberts <tjrob...(a)sbcglobal.net> wrote: > kenseto wrote: > > one-way isotropy is not a direct measure of the value of the > > one-way speed of light. Why? You can have 200,000 Km/sec isotropy or > > 300,000 Km/sec isotropy. > > No. It is true that tests for isotropy do not directly measure the value of the > speed. But once they demonstrate isotropy then the value of the one-way speed > involved can only be equal to the KNOWN value for the round-trip speed of light > in vacuum. After all, the round-trip paths used in such measurements consist of > two one-way paths in series. The problem with that approach is that the value for the round-trip speed of light is the average of (outbound speed +inbound speed)/2. Clearly this does not tell you that the outbound speed is equal to inbound speed as required by the one-way isotropy. > > > Besides, since they performed experiments to measure for one-way > > isotropy why didn't they report the value of one-way speed of light > > for those same experiments? > > Because, as I keep telling you and you keep ignoring, most tests for isotropy > cannot obtain a value for the speed. Such experiments are optimized for > measuring the anisotropy, and generally do this with difference techniques, not > by measuring the value of the one-way speed and then subtracting values. > > You might have heard of the Michelson-Morley experiment. It > measures the anisotropy in the round-trip speed of light, but > is completely incapable of providing a value for the speed > of light itself. The Michelson-Morley experiment was done with short distances and even that showed 6 fringe shift. This small fringe shift was attrubuted to experimental error. But what if the arms of the MMX is much longer will there be larger fringe shift? The point is, in aether theory, the value for the one-way speed of light is distance dependent. Your anisotropy experiments does not address this issue at all. Ken Seto > > If you would LEARN something about the subject and STUDY the experiments, you > would know all this already. > > Tom Roberts
From: Androcles on 12 Jan 2010 13:14 "kenseto" <kenseto(a)erinet.com> wrote in message news:f84dbe65-a6ab-4a71-bb9c-b7a6d66f1041(a)u41g2000yqe.googlegroups.com... On Jan 11, 5:29 pm, Tom Roberts <tjrob...(a)sbcglobal.net> wrote: > kenseto wrote: > > one-way isotropy is not a direct measure of the value of the > > one-way speed of light. Why? You can have 200,000 Km/sec isotropy or > > 300,000 Km/sec isotropy. > > No. It is true that tests for isotropy do not directly measure the value > of the > speed. But once they demonstrate isotropy then the value of the one-way > speed > involved can only be equal to the KNOWN value for the round-trip speed of > light > in vacuum. After all, the round-trip paths used in such measurements > consist of > two one-way paths in series. The problem with that approach is that the value for the round-trip speed of light is the average of (outbound speed +inbound speed)/2. Clearly this does not tell you that the outbound speed is equal to inbound speed as required by the one-way isotropy. =============================================== The real problem is the outbound DISTANCE does not equal the inbound distance. http://www.androcles01.pwp.blueyonder.co.uk/Shapiro/Crapiro.htm Hey Seto! I drive to London, 30 miles, in half an hour. That's 60 mph. I drive home again (in heavy traffic) in one hour. That's 30 mph. Is my average speed, 60 miles in 90 minutes, 60/1.5 = 40 mph or (60 mph + 30mph) divided by 2 = 45 mph?
From: PD on 12 Jan 2010 13:19 On Jan 12, 11:35 am, kenseto <kens...(a)erinet.com> wrote: > On Jan 11, 5:29 pm, Tom Roberts <tjrob...(a)sbcglobal.net> wrote: > > > kenseto wrote: > > > one-way isotropy is not a direct measure of the value of the > > > one-way speed of light. Why? You can have 200,000 Km/sec isotropy or > > > 300,000 Km/sec isotropy. > > > No. It is true that tests for isotropy do not directly measure the value of the > > speed. But once they demonstrate isotropy then the value of the one-way speed > > involved can only be equal to the KNOWN value for the round-trip speed of light > > in vacuum. After all, the round-trip paths used in such measurements consist of > > two one-way paths in series. > > The problem with that approach is that the value for the round-trip > speed of light is the average of (outbound speed +inbound speed)/2. > Clearly this does not tell you that the outbound speed is equal to > inbound speed as required by the one-way isotropy. You're almost on it, Ken. The isotropy experiments tell you that the outbound speed equals the outbound speed. If they were different, then these experiments would measure a nonzero anisotropy, but they don't. Now that you know that the outbound speed equals the inbound speed, then you know that the two-way light speed equals the one-way light speed. > > > > > > Besides, since they performed experiments to measure for one-way > > > isotropy why didn't they report the value of one-way speed of light > > > for those same experiments? > > > Because, as I keep telling you and you keep ignoring, most tests for isotropy > > cannot obtain a value for the speed. Such experiments are optimized for > > measuring the anisotropy, and generally do this with difference techniques, not > > by measuring the value of the one-way speed and then subtracting values.. > > > You might have heard of the Michelson-Morley experiment.. It > > measures the anisotropy in the round-trip speed of light, but > > is completely incapable of providing a value for the speed > > of light itself. > > The Michelson-Morley experiment was done with short distances and even > that showed 6 fringe shift. This small fringe shift was attrubuted to > experimental error. But what if the arms of the MMX is much longer > will there be larger fringe shift? The point is, in aether theory, the > value for the one-way speed of light is distance dependent. Your > anisotropy experiments does not address this issue at all. > > Ken Seto > > > > > If you would LEARN something about the subject and STUDY the experiments, you > > would know all this already. > > > Tom Roberts
From: PD on 12 Jan 2010 13:20 On Jan 12, 11:35 am, kenseto <kens...(a)erinet.com> wrote: > On Jan 11, 5:29 pm, Tom Roberts <tjrob...(a)sbcglobal.net> wrote: > > > kenseto wrote: > > > one-way isotropy is not a direct measure of the value of the > > > one-way speed of light. Why? You can have 200,000 Km/sec isotropy or > > > 300,000 Km/sec isotropy. > > > No. It is true that tests for isotropy do not directly measure the value of the > > speed. But once they demonstrate isotropy then the value of the one-way speed > > involved can only be equal to the KNOWN value for the round-trip speed of light > > in vacuum. After all, the round-trip paths used in such measurements consist of > > two one-way paths in series. > > The problem with that approach is that the value for the round-trip > speed of light is the average of (outbound speed +inbound speed)/2. > Clearly this does not tell you that the outbound speed is equal to > inbound speed as required by the one-way isotropy. > > > > > > Besides, since they performed experiments to measure for one-way > > > isotropy why didn't they report the value of one-way speed of light > > > for those same experiments? > > > Because, as I keep telling you and you keep ignoring, most tests for isotropy > > cannot obtain a value for the speed. Such experiments are optimized for > > measuring the anisotropy, and generally do this with difference techniques, not > > by measuring the value of the one-way speed and then subtracting values.. > > > You might have heard of the Michelson-Morley experiment.. It > > measures the anisotropy in the round-trip speed of light, but > > is completely incapable of providing a value for the speed > > of light itself. > > The Michelson-Morley experiment was done with short distances and even > that showed 6 fringe shift. This small fringe shift was attrubuted to > experimental error. But what if the arms of the MMX is much longer > will there be larger fringe shift? The point is, in aether theory, the > value for the one-way speed of light is distance dependent. Your > anisotropy experiments does not address this issue at all. Isotropy experiments have been done with much longer arms than the MMX, Ken. Do catch up. > > Ken Seto > > > > > If you would LEARN something about the subject and STUDY the experiments, you > > would know all this already. > > > Tom Roberts
From: Da Do Ron Ron on 12 Jan 2010 13:38
Andie noted: >He said this: > http://www.androcles01.pwp.blueyonder.co.uk/Shapiro/Crapiro.htm To Androcles: Your answer was inadequate because it does not pertain to the invariance of light's one-way speed. Invariance calls for more than one frame, and yet your cited link site mentioned only a single frame's clocks. (These are clocks A & B.) (Hint: The only way to involve two or more physically separate frames is by using only one light source for all frames. (Giving each frame its own source is simply repeating one frame over and over).) Try again, Androcles. BTW, Tom was wise to ignore my query. (Better an cute little incomplete than a flat-out F!) Maybe PD can help you (and Tom)? (And the fact that Seto also ignored my query speaks volumes about his understanding of the one-way speed of light case; he had his chance to pounce on Roberts with something strong, but missed it!) ~~RA~~ |