A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
|
From: PD on 8 Mar 2010 17:38 On Mar 6, 5:41 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 5 Mar, 16:02, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Mar 5, 2:55 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 4 Mar, 18:12, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Mar 4, 12:04 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > On 4 Mar, 17:46, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Mar 4, 11:17 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > > On 4 Mar, 16:49, mpalenik <markpale...(a)gmail.com> wrote: > > > > > > > > > On Mar 4, 11:45 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > > > > On 4 Mar, 16:32, mpalenik <markpale...(a)gmail.com> wrote: > > > > > > > > > > > On Mar 4, 11:28 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > > > > > > On 4 Mar, 16:20, mpalenik <markpale...(a)gmail.com> wrote: > > > > > > > > > > > > > On Mar 4, 10:31 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > > > > > > > > On 4 Mar, 13:40, mpalenik <markpale...(a)gmail.com> wrote: > > > > > > > > > > > > > > > On Mar 4, 3:12 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > > > > > > > > > > On 3 Mar, 20:01, mpalenik <markpale...(a)gmail.com> wrote: > > > > > > > > > > > > > > > > > On Mar 3, 12:52 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > > > > > > > > > > > > No. In SR, clocks *appear* to run slower as you are increasing your > > > > > > > > > > > > > > > > > distance from the clock. The effect is entirely apparent in SR. > > > > > > > > > > > > > > > > > You must just go through the entire thread and not pay any attention > > > > > > > > > > > > > > > > to what anybody says. Ever. > > > > > > > > > > > > > > > > > 1) What you've stated above is not an effect of SR. It is an effect > > > > > > > > > > > > > > > > of propagation delay, which was used to calculate c from the motion of > > > > > > > > > > > > > > > > the moons of jupiter hundreds of years ago. > > > > > > > > > > > > > > > > Ok. > > > > > > > > > > > > > > > > > 2) If you were to move TOWARD the clock, it would appear to run > > > > > > > > > > > > > > > > faster. But SR says nothing about whether you are moving toward or > > > > > > > > > > > > > > > > away from an object. > > > > > > > > > > > > > > > > <suspicious eyebrow raised> Ok. > > > > > > > > > > > > > > > > > 3) The amount that the clock would appear to slow down is DIFFERENT > > > > > > > > > > > > > > > > from the amount that SR predicts the clock *actually* slows down > > > > > > > > > > > > > > > > Really? I'm growing increasingly suspicious. In what way does SR > > > > > > > > > > > > > > > predict the "actual" slowdown, as opposed to the "apparent" slowdown? > > > > > > > > > > > > > > > And for example, if we racked up the value of 'c' to near infinity, > > > > > > > > > > > > > > > would SR still predict an "actual" slowdown, even though the > > > > > > > > > > > > > > > propagation delays would approach zero? > > > > > > > > > > > > > > > With what you have described, I checked just to be sure, even though I > > > > > > > > > > > > > > was already pretty sure what the answer would be, the time you read > > > > > > > > > > > > > > moving away the clock would be: > > > > > > > > > > > > > > > t2 = t - (x+vt)/c = t(1-v/c) - x > > > > > > > > > > > > > > > and when you move toward the clock > > > > > > > > > > > > > > > t2 = t + (x+vt)/c = t(1+v/c) + x > > > > > > > > > > > > > > > so moving away from the clock: > > > > > > > > > > > > > > dt2/dt = 1-v/c > > > > > > > > > > > > > > and toward > > > > > > > > > > > > > > dt2/dt = 1-v/c > > > > > > > > > > > > > > > Special relativity predicts that the moving clock will always slow > > > > > > > > > > > > > > down as > > > > > > > > > > > > > > dt2/dt = sqrt(1-v^2/c^2) > > > > > > > > > > > > > > > What you *measure* is a combination of the actual slow down predicted > > > > > > > > > > > > > > by SR (sqrt(1-v^2/c^2) and whatever changes occur due to propagation > > > > > > > > > > > > > > delays (which depend on the direction of motion). > > > > > > > > > > > > > > Ok. So let us suppose that we take two clocks. Separate them by a > > > > > > > > > > > > > certain distance, synchronise them when they are both stationary, and > > > > > > > > > > > > > then accelerate them both towards each other (and just before they > > > > > > > > > > > > > collide, we bring them stationary again). Are you seriously saying > > > > > > > > > > > > > that both clocks report that the other clock has slowed down, even > > > > > > > > > > > > > though they have both undergone symmetrical processes? Because there > > > > > > > > > > > > > is obviously a contradiction there. > > > > > > > > > > > > > Yes, that is correct. Both will report a slow down. And in fact, > > > > > > > > > > > > which ever one breaks the inertial frame to match speed with the other > > > > > > > > > > > > is the one that will be "wrong". This is still within the realm of > > > > > > > > > > > > SR, not GR. > > > > > > > > > > > > What if they both "break the inertial frame"? > > > > > > > > > > > Then whichever frame they both accelerate into will be the one that > > > > > > > > > > has measured the "correct" time dilation. > > > > > > > > > > So in other words, the clocks will register the same time, but will > > > > > > > > > have slowed in some "absolute sense"? > > > > > > > > > Yes--assuming they both accelerated by the same amount (that is to > > > > > > > > say, assuming they both broke the inertial frame in a symmetric way). > > > > > > > > Otherwise, they will register different times. > > > > > > > > Agreed. > > > > > > > > So let's explore an extension of this scenario. Let's say you have two > > > > > > > clocks, and you accelerate both of them up to a common speed, and > > > > > > > after they have travelled a certain distance, you turn them around and > > > > > > > return them to the starting point. The only difference is that one > > > > > > > clock goes a certain distance, and the other clock goes twice that > > > > > > > distance, but they *both* have the same acceleration profile - the > > > > > > > only difference is that one clock spends more time travelling on > > > > > > > inertia. > > > > > > > > Obviously, one clock will return to the starting point earlier than > > > > > > > the other. But when both have returned, are their times still in > > > > > > > agreement with each other, or have they changed? > > > > > > > Agreement. Both of them will agree, but will be showing a time earlier > > > > > > than a third clock that was left behind at the starting point. > > > > > > Oh dear. Mark contends otherwise. > > > > > Right. I misunderstood. He's right. I was wrong. > > > > Ok. So what you're (both) saying is that time dilation (in SR) is a > > > simple function of speed and distance, so that the quicker you travel > > > the more time dilates, and the further you travel the more time > > > dilates? And, to boot, you're saying that it's only *relative* > > > distance and speed that counts (i.e. there is no absolute measure of > > > movement in space)? > > > The time dilation *factor* (by what factor is the clock moving more > > slowly) is a simple function of relative speed. The difference in the > > time *elapsed* between the two clocks is also a function of the > > relative distance. > > > This should make perfect sense to you. If a clock is running 2% > > slower, then it is running 2% slower regardless of distance. But if, > > as a result of running 2% slower, it falls behind 6 minutes after > > running a certain amount of time, then it will fall behind 12 minutes > > after running for twice as long. > > Agreed. > > The question now is, if we agree that both clocks suffer time dilation > in this way, then when they return to the start point, how do they > each reconcile the fact that (after accounting for the effects of > acceleration) it ought to be the other clock which is slow, when in > fact one clock (the one that went furthest from the start point) will > be slower than the other? And a third clock, left at the start point, > will be running ahead of both? You asked this question better in a different subthread, and so I'll answer it there.
From: Jerry on 8 Mar 2010 19:00 On Mar 8, 4:33 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Mar 8, 4:06 pm, Jerry <Cephalobus_alie...(a)comcast.net> wrote: > > > On Mar 8, 1:46 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > That's correct. LET makes no statement whatsoever about strong, weak, > > > and gravitational forces. > > > Precisely. Strong and weak forces were unknown in 1904. > > > > However, it is right to expect that if LET > > > *is* correct in its application to the electromagnetic force, then it > > > *should* be applicable in the case of the other forces. > > > Why? > > Because the other forces are just as manifestly covariant as > electromagnetism. See below. > > > > > Even Lorentz never claimed that that the LET aether might be > > applicable to gravitation. Instead, he studied various > > alternative aethers, including a model similar to that of Le > > Sage, ultimately rejecting his efforts as unsatisfactory. > > > If one wishes to claim that a single aether acts as the > > propagating medium for all four forces, that necessarily leads > > to the question of how these forces manage to show such distinct > > properties. > > Indeed. Especially since the weak force is mediated by carriers that > generally do not travel at c, and the interaction is STILL Lorentz > covariant. KLUNK!!! (sound of jaw dropping on the floor...) Now THAT is interesting!!!! Reference? That's worth making a special trip to the university library!!! > > The fact is, no plausible unified aether theory exists. There is > > no reason whatsoever for aether theories to predict a common > > speed of propagation for any of the fundamental forces. > > > > You can take a more limited stance and says that the Lorentz > > > covariance of the electromagnetic force is explained by LET, and the > > > Lorentz covariance of the other forces is completely unexplained. > > > However, SR provides a model that DOES explain the Lorentz covariance > > > of all four forces, and in this sense it wins by broadness of > > > application. > > > Yes. > > > > You would even take the stance that Lorentz covariance of the > > > electromagnetic force is explained by LET, and the Lorentz covariance > > > of the other forces is explained by special relativity. But this would > > > be an obviously obstinate stance. Jerry
From: Paul Stowe on 8 Mar 2010 20:43 On Mar 7, 6:15 pm, "Inertial" <relativ...(a)rest.com> wrote: > "PaulStowe" <theaether...(a)gmail.com> wrote in message > > news:aa26451b-dcb7-4bbf-8577-063efc1a2c72(a)c34g2000pri.googlegroups.com... > > >> Only because it has been MEASURED to behave as SR says. It is an > >> observed 'fact'. > > > And, as LET explains... SR says nothing, as he says, SR stipulates it > > as a base assumption... LET provides an actual explanation for the > > behavior. > > SR explains it as having to be c due to the geometry of spacetime That's simply a silly idea... > >> Nature came first on this one .. light DOES travel at c in all frames of > >> reference. > > > Light speed is independent of all motion of physical elements. > > AS I said > > > Again > > LET explains what causes it to be 'measured' as invariant. > > So does SR. LET says its due to light not ACTUALLY travelling at c (in the > only frame where what we measure is what is read .. the supposed aether > frame) .. only giving the appearance due to distorted rulers and clocks. > There are no such distortions in SR No, LET says light actually always travels at speed c, the propagation velocity of the medium. In LET that is not changed regardless of motion. In fact, the gamma factor IS the result of this. It's a simply derivation to show this. > >> No idea. > > > Yup, certainly not you, I don't think you'll ever admit the validity > > of LET... :) > > LET is as possibly valid as SR .. Neither is refuted experimentally. I just > don't think it is the correct physical explanation. LET is not compatible > AFAIK with GR .. so is a bit of a dead end .. and has the assumption of an > undetectable aether with properties that don't make sense. Mea cupa,I stand corrected. In fact LET is a better foundation in physical science than SR. The physical model (aetherial medium) on which is LET is founded is perfectly compatible with GR. In fact, it fits GR better given the fundamental hydrodynamical form of its mathematics. It even easier to explain its behavior in a more unified manner. > > To Bruce, you know what's said about trying to teach > > pigs to sing... > > > Paul Stowe
From: Paul Stowe on 8 Mar 2010 20:46 On Mar 7, 8:15 pm, "Inertial" <relativ...(a)rest.com> wrote: > "PaulStowe" <theaether...(a)gmail.com> wrote in message > > news:ec6405e7-99b7-4137-9a8b-a97f41c4171d(a)s36g2000prh.googlegroups.com... > > > > > > > On Mar 7, 7:20 pm, "Inertial" <relativ...(a)rest.com> wrote: > >> "PaulStowe" <theaether...(a)gmail.com> wrote in message > > >>news:f0ae8888-de0b-4d93-862b-9b1d2cd005f3(a)k6g2000prg.googlegroups.com.... > > >> > On Mar 7, 7:04 pm, PaulStowe<theaether...(a)gmail.com> wrote: > >> >> On Mar 7, 6:52 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > >> >> wrote: > > >> >> > > LET is as possibly valid as SR .. Neither is refuted > >> >> > > experimentally. > >> >> > > I > >> >> > > just don't think it is the correct physical explanation. LET is > >> >> > > not > >> >> > > compatible AFAIK with GR .. so is a bit of a dead end .. and has > >> >> > > the > >> >> > > assumption of an undetectableaetherwith properties that don't make > >> >> > > sense. > > >> >> > The experimental support for a fixed ether in SR is comparable to > >> >> > the > >> >> > experimental support for unicorns in zoology. Lots of luck proving > >> >> > either > >> >> > exists. > > >> >> What is a 'fixed ether'? > > >> >> PaulStowe > > >> > Oh, and BTW, please derive the physical basis of the LTE within the > >> > framework of SR. > > >> LTE? > > > Lorentz Transform Equation => Sqrt(1 - [v/c]^2) > > Ok .. it is more standard to refer to the Lorentz Transforms as 'LT', rather > than 'LTE' > > And Sqrt(1 - [v/c]^2) is not it. That's the value usually referred to as a > gamma factor. > > Se Einstein's 1950 paper for a derivation from basic axioms (in particular > the 'physical' speed of light as c). It also comes out naturally from the > geomtry of space being minkowski rather than Euclidean (from which one gets > the basis for Gallilean transforms). One does not need a 'physical' basis > for Gallilean transforms (other than the assumed geometry of space), so one > doesn't need one for Lorentz Transforms (other than the assumed geometry of > spacetime) Minkowski isn't fundamental, and, in fact, trying to use it is a classic circular argument. Paul Stowe
From: Paul Stowe on 8 Mar 2010 20:51
On Mar 7, 8:32 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > "PaulStowe" <theaether...(a)gmail.com> wrote in message > > news:9c1e1ae6-c9c1-497d-a293-35fb68100abb(a)c34g2000pri.googlegroups.com... > On Mar 7, 8:10 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > wrote: > > > > > > > "PaulStowe" <theaether...(a)gmail.com> wrote in message > > >news:720fa6a7-6744-4bf7-85fe-6050215ee277(a)k5g2000pra.googlegroups.com... > > On Mar 7, 6:52 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > wrote: > > > > > LET is as possibly valid as SR .. Neither is refuted experimentally.. I > > > > just don't think it is the correct physical explanation. LET is not > > > > compatible AFAIK with GR .. so is a bit of a dead end .. and has the > > > > assumption of an undetectableaetherwith properties that don't make > > > > sense. > > > > The experimental support for a fixed ether in SR is comparable to the > > > experimental support for unicorns in zoology. Lots of luck proving > > > either > > > exists. > > > What is a 'fixed ether'? > > > _______________________ > > Non-existent. > > That is your 'belief'. The question was in physical model arena. > Give or reference a basic hypothetical definition... > > _____________________________ > A priveleged inertial reference frame. Of course, as I don't believe it > exists, I am hardly in a position to extol its qualities. This seems to be > what believers in a "fixed ether" mean by the term, but you would be better > off asking them. I know as much about ether as I do about Unicorns. In fact, > I don't even know if Unicorns are horses with a single spiral horn, or are a > completely different species that just looks like a horse with a horn. If > you really want to know, ask somebody who believes in Unicorns and/or the > fixed ether what they are exactly. > > Paul Stowe I'm sorry about these questions but, what does privileged mean? There is certainly physical consequences of the medium (such as field profile alterations due to motion) but there is certainly nothing priveleged as in having different properties about it. |