Ballistic Theory, Progress report...Suitable for 5yo Kids
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From: Paul B. Andersen on 13 Sep 2005 06:34 Henri Wilson wrote: > > Use a four mirror system. Paul B. Andersen wrote January 2005: | Done. | In less than one hour. | To a first order approximation, (that is, ignoring | terms containing higher than first order of | the tangential mirror speed v) the light will use | the same time in both directions. | The math isn't very hard, but it isn't trivial either. | I won't bother to go through all the math in this awkward | medium, but I will write the first order terms: | The length of one chord of the light path will be: | d = srt(2)*r + v*t/sqrt(2) | where r is the radius of the circle tangenting the mirrors, | and t is the time the light uses to traverse the chord. | The speed of the light will be: | c' = c + v/sqrt(2) | Note that these equations are valid for both direction, | v being negative for the beam going in the opposite direction. | So we have: | c'*t = d | c*t + v*t/sqrt(2) = sqrt(2)*r + v*t/sqrt(2) | t = sqrt(2)*r/c | The ballistic theory predicts that the time | has no first order dependency on the speed! | | The sagnac effect IS a first order effect! | | You are proven wrong. Henri Wilson responded: | I did that calculation a long time ago. So why keep discussing what is settled a long time ago? The ballistic theory predicts no Sagnac effect. The ballistic theory is falsified. Paul
From: George Dishman on 13 Sep 2005 14:53 "Henri Wilson" <H@..> wrote in message news:p589i1lsa6hn9vb4t77eb9dof9lkath82u(a)4ax.com... > On Sat, 10 Sep 2005 14:03:20 +0100, "George Dishman" > <george(a)briar.demon.co.uk> > wrote: > >> >>"Jeff Root" <jeff5(a)freemars.org> wrote in message >>news:1126290183.817714.111790(a)z14g2000cwz.googlegroups.com... >>> Henri Wilson replied to Jeff Root: .... >>>> George was wrong. >>>> He thought that during rotation, the source moves towards the >>>> next mirror. It doesn't. It moves at right angles to it. >>> >>> I'll let George respond to that, if he wants to. >> >>I thought no such thing, I have no idea how Henri >>came to that conclusion. There are only two frames >>I have ever used in serious analysis, an inertial >>"lab" frame with origin at the centre of the table >>and the non-inertial "co-rotating" frame which also >>has the origin at the centre of the turntable but >>is rotating at the same speed as the table. It is >>obviously the speed of the light that affects the >>time taken, not the speed of the mirror. >> >>In the former frame, for v<<c and a square setup >>(three mirrors and the source/detector), the speed >>of the light according to Ritz would be: >> >> v' = c +/- v/sqrt(2) > > Consider a single photon. > When it is emitted, it has the above component velocity in the direction > of the > next mirror AT THAT INSTANT. Thank you, that was the point. The motion of the _mirror_ is not relevant, what matters is that the speed of the _light_ should be modified by the speed of the source according to Ritz. > However the next mirror will move before the photon reaches it. > The component in the direction of the mirror WHEN THE PHOTON ARRIVES is > not > described by the above equation. "For v<<c ..." the equation is correct. The deviation from that due to mirror movement depends on (v/c)^2 which is negligible compared to the 71% of v that should be added to the emission speed. .... >>I think the reason Henri keeps tossing in these vague >>hand-waving arguments is that he has come to realise >>that every quantitative analysis gives the same null >>result under the Ritzian model. Turning a blind eye >>is all he can do now. > > It is not related to light speed at all. The sagnac effect is caused by > the > fact photons have an 'axis' and that axis wants to remain in the same > direction. .... Whatever bizarre mechanism you might postulate, it doesn't matter. The way interference behaves has been fully _characterised_ since the beggining of classical optics. The relative intensity depends on the relative phase. In real world closed loop devices, the output is held constant by introducing an additional well defined phase delay which compensates for that produced by the Sagnac effect. George
From: Jeff Root on 13 Sep 2005 14:58 Jim Greenfield replied to Jeff Root: >> >> >> > With train stationary, ray from ceiling would strike earth >> >> >> > center; >> >> >> >> >> >> OK-- You're talking about a light ray going from the ceiling >> >> >> of a railcar straight down to the floor, and beyond. >> >> >> >> >> >> > when train is in motion, by ANY analysis, the ray's direction >> >> >> > is ALTERED- it no longer strikes center. >> >> >> >> >> >> Relative to the world outside the railcar, the ray's >> >> >> direction is altered. Of course, to a person on the >> >> >> railcar, not knowing whether the car is moving, or in >> >> >> which direction or at what speed, the ray's direction >> >> >> is not altered-- it is still going from the ceiling >> >> >> straight down to the floor. >> >> > >> >> > Hooray!!!!!!This is what I have been saying on this group >> >> > forever; that the observers MAKE MISTAKES!!!!!! Because the >> >> > train rider is denied the information about the REAL situation >> >> > (being able to know that he is moving), he is MISTAKEN/TRICKED >> >> > as to the true situation. >> >> >> >> What gives you the idea that the person on the train has >> >> been tricked or is mistaken about the true situation? >> >> He sees the light go from the ceiling straight down to the >> >> floor, and that is exactly what happens. > > Do you REALLY want to stick to this statement????????? Definitely! > The most cursory read of your following finds you admitting > that this is exactly what DOESN'T happen. Correct! That is, indeed, what you find with the most cursory reading. You need to go beyond the cursory reading if you want to understand anything. > When train is in motion ref earth/track/LINE!!!) an alteration > takes place to the light path ACROSS THE UNIVERSE. You admit > below that the passenger knows (or SHOULD know, that this is so) Certainly. > (see my reply to George as to why we cannot know what this is > in absolute terms) That is the basis of Galilean relativity. >> > Rubbish! Read above again to realise that he IS mistaken- and >> > I can prove it! Cut a hole in the floor, and where before the >> > train rider was SURE that the beam is vertical, he actually >> > finds out that he was mistaken/WRONG, when he sees the beam >> > MISS the earth's centre (flat earth) > > Read more carefully before replying, and you will avoid apology > (accepted) in subsequent posts I'll try. >> You are still failing to think the problem through. I know >> that because you are leaving out several key pieces of your >> argument. Without those pieces, your argument doesn't have >> any conclusion. It isn't an argument at all-- just a set >> of statements about a scenario, which don't make any point. > > Point: AE claims time "dilates" I've never used the term "time dilation", and I don't know whether Einstein did, either. It is used to describe the effects of relative motion on measurements, and I suspect it can be misleading. I will assume that it represents the relation t' = (t-((v/c^2)*x))/SQRT(1-(v^2/c^2)), in which case I have no problem with it. > because the passenger sees a different length path for the > light, than does a trackside observer (longer therefore more > time elapsed for photon journey when train moving on track). > Here we have established that the passenger was mistaken, > due to lack of information; No, you haven't established any such thing. The passenger sees a path straight down from the ceiling to the floor, and the trackside observer sees a longer, diagonal path from the ceiling to the floor. Both observations are 100% correct and accurate. > when appraised of the true situation (that the passenger > slept through the accelleration), both observers agree that > there were NO alterations to time taken from ceiling to floor, > because in the moving scenario, both agree the light travels > the diagonal (longer), and takes the SAME amount of time to do > so, because it is moving faster. (see "Jim's Motion Detector") No, the trackside observer does not see the light move faster. He still sees the light move at c. The trackside observer agrees that the passenger sees a short, straight-down path, which takes a short time for the light to travel. The passenger agrees that the trackside observer sees a longer, diagonal path, which takes a longer time for the light to travel. >> Let me start with the least important bits, mainly to show >> that you are in fact leaving things out. >> >> You suggest parenthetically that Earth can be considered >> flat for this thought experiment. I'm pretty sure that >> the reason you suggest it is the fact that on a spherical >> Earth, the train has to move in a circle, so the direction >> of "down" changes constantly, and you wanted to avoid that >> complication. Obviously, a flat Earth has no center, so >> your scenario would be lost. But all of that is irrelevant >> to your problem. The only function of Earth's center in >> this thought experiment is as a reference point separate >> from the train. > > We agree a change in direction occurs to the beam when source > has motion altered. Yes. Your wording is tricky, because it is incomplete, but I'll agree. >> The Earth itself is irrelevant to your thought experiment. >> The train could be replaced by a spacecraft, and Earth's >> center replaced by a lost sock flying through space at some >> distance from the spacecraft. That scenario is completely >> equivalent to yours. >> >> However, I'll stick with your train scenario. >> >> Rather than suggesting a flat Earth, you could specify >> that the experiment takes place over a short distance, >> so Earth's curvature isn't a factor. We can still presume >> that Earth's center is a mathematical point, so any motion >> of the train will cause the light beam to miss it. >> >> The second relatively unimportant bit is the business about >> cutting a hole in the floor. You never say why the hole >> is made. You never say how the hole is used. You never >> say that the observer looks through the hole or makes some >> measurement through it, and you never say what he sees or >> measures. It is a gaping hole in your argument. It forces >> me to make part of your argument *for* you! > > Gaping hole in your comprehension :-) The hole was irrelevant. The questions were 1) Where does the light go? 2) Does the passenger know where the light goes? Since there was no reason for the passenger not to know the motion of the train wrt the Earth, he knows where the light goes. Thus, no reason to suggest that the hole was a significant, new feature in the thought experiment. >> Now something more important you left out. You claim >> that "the train rider was SURE that the beam is vertical". >> Apparently you meant vertical relative to Earth. You >> didn't say that, so I have to do your work for you and >> guess. The experimenatal setup specifies that the light >> beam goes straight "down" from the ceiling to the floor, >> so, relative to the railcar, the beam obviously *is* >> vertical. So you must mean relative to the Earth. >> >> Next, WHY was the train rider sure the beam was vertical >> relative to the Earth? You didn't say. What observation >> was his belief based on? You didn't say. If the rider >> could not see outside the car, and had no knowledge of >> whether it was moving or not, then surely he would know >> that he could *not* know whether the beam was vertical >> relative to the Earth. Do you agree? > > If he "knew" f*a, how could he make ANY comment on time > dilation? I don't know what you mean by "f*a". I thought it might be a disguised vulgarity, but couldn't find it in a search of multiple dictionaries of acronyms and abbreviations. If you are simply agreeing, you could make that clear. >> If the rider *could* see outside the car, and measure its >> motion relative to the earth, then he would be able to >> correctly determine whether the beam was vertical relative >> to the Earth. Do you agree? > > .as I've been saying it foe years............... Okay. >> >> If he doesn't know whether or how the railcar is moving >> >> relative to the Earth, then he doesn't know where the light >> >> beam will go relative to Earth's center. He will only be >> >> mistaken if he *thinks* he knows how the railcar is moving >> >> relative to the Earth, but is wrong. I'm sure that isn't >> >> the scenario you're interested in. >> > >> > It certainly is! The passenger thinks he is ststionary ref the >> > line at all times, and THAT is why he thinks the beam is VERTICAL >> > at all times. >> >> What "line"? This is the first mention of a "line". > > (sigh) railway line I never would have guessed that. Why would the passenger think he is stationary wrt the ground? If he can't see out the window, and doesn't know whether the train is moving wrt the Earth, then he will know that he doesn't know. He won't assume that the train is stationary on the track. <Tiny snip> >> > Give him the true situation/information, and he deducts >> > the truth. >> >> I agree with that! > > Thank you. > Now you have a passenger who "sees/knows" that the ray which > was heading for earth center (or wherever) has had its velocity > altered. If he was ignorant of measurements of the speed of light under a variety of conditions, then he would think that. If he knew about those observations, he would not. Instead, he would know that the speed of light is c. > ........and c (velocity) can NEVER alter under SR > (which is why it is wrong for predicting both time dilation, > and length contraction, due to velocity) You haven't shown any contradiction-- neither a logical contradiction within the theory, nor a contradiction with observations. You are making an extremely elementary argument about an extremely elementary part of relativity theory. The sort of thing that can be covered in the first day of class. >> > NB that I don't make claim as to what he SEES; the ray NEVER >> > strikes the eye of any observer in this dendanken- >> >> To determine whether the beam hits Earth's center, just put >> a photocell down there. That's no problem. > > So will it be stuch when the train is moving? Do you mean, "will the beam hit Earth's center when the train is moving?" No, of course not. >> > the whole idea is based on the assumption that c=c+v BEFORE >> > the clocks are started (they are not ticking in sync) >> >> As you pointed out at the start (September 6), there are NO >> clocks in this thought experiment. So this comment appears >> to be completely irrelevant. If it has any relevance, you >> didn't say what it is. >> >> >> > He can easily get it right by drilling a hole in the floor, >> >> > and coming back later to see where the ray ACTUALLY was headed >> >> > when the train was in motion. >> >> >> >> Or by looking out the window and seeing how the train is >> >> moving relative to the Earth. He's smart enough to realize >> >> that if he doesn't know how the train is moving relative >> >> to the Earth, he can't determine where the light will go >> >> relative to the Earth. Duh. >> >> >> >> > Must we be condemned to believe a falsehood about light >> >> > propagation forever, because the passenger has the WRONG >> >> > information, and reaches the WRONG conclusion???????/ >> >> > Not yours t! >> >> >> >> You need to think about the scenario more carefully. >> >> >> >> >> > FYI, this is a CHANGE IN VELOCITY; not only in direction, >> >> >> > which is integral to velocity, >> >> >> >> >> >> Yes the velocity has changed, but only in direction. >> >> >> The magnitude of the velocity (speed) is unchanged. > > Check out the triangle; ceiling/floor/diagonal (hypotenuse). Yes. Very elementary geometry. Very obvious. Einstein's theory of relativity is based on geometry. In his book, "Relativity: The Special and the General Theory", Part I, Chapter 1 is titled "Physical Meaning of Geometrical Propositions". The first paragraph of the book (in English): In your schooldays most of you who read this book made acquaintance with the noble building of Euclid's geometry, and you remember--perhaps with more respect than love-- the magnificent structure, on the lofty staircase of which you were chased about for uncounted hours by conscientious teachers. By reason of your past experience, you would certainly regard everyone with disdain who should pronounce even the most out-of-the-way proposition of this science to be untrue. But perhaps this feeling of proud certainty would leave you immediately if some one were to ask you: "What, then, do you mean by the assertion that these propositions are true?" Let us proceed to give this question a little consideration. He answers that question in the next paragraph. The rest of the book answers all of your objections in detail. > Something moving on the vertical reaches the floor quicker > than along the diagonal, if the MAGNITUDE of their motions > is the same. Think about it! Draw it! It happens that geometry is something I excel at. As an example which I hope I haven't trotted out here previously, in high school geometry I solved a homework problem which no-one else in my teacher's three classes (80-90 students) solved. I thought the problem was easy. It had a pretty construction. A 2-D representation of a 3-D object. > Google on "slot clock"! This, however, I seem to fail at. The most promising hits on "slot clock" were about high-speed communications, and most of those were Intel research papers. A slot, in that context, is a window of fixed-length time in which one machine is allowed to transmit messages to another. No dictionary had a definition of the term. George seemed to know what you meant, though. Whatever it is wasn't among the first thirty Google hits. >> > Then it will take longer to reach the floor, as it is >> > travelling a LONGER path. Or doesn't v=d/t?? >> >> The passenger, stationary wrt the light beam, finds that >> the light takes the same amount of time to reach the floor >> nomatter how the train is moving relative to the Earth, >> since it is always travelling the same path: from the >> ceiling to the floor. >> >> An observer stationary wrt the Earth finds that the light >> takes longer to reach the floor when the train is moving, >> because the light travels a longer path, as you say. > > Nope! Same amount of time, as the light travels faster on > the longer journey The speed of light has been measured countless times, with the light originating from many different kinds of sources, many of them moving at very high speed relative to the observer. It is always measured to be c. >> You think that the observer on the Earth is right, and >> the observer on the train is wrong. > > See reply to George; they may well both be wrong ref universal > absolute time, but I think their clocks will ALL show the same > time lapses for the light paths anyway, if the clocks are > ticking at the same rate (sync) to begin with. The passenger on the train measures the time with his very accurate clock, and the observer on the ground measures the time with his equally-accurate clock. They each find that the time to cover the path is consistent with the distance the light travels: a short distance for the passenger, and a longer distance for the observer on the ground. Both find that the speed of the light is c. That is what is actually observed in real experiments. > You will find that perseverence with the arguement leads to > the clock on the train altering as it increases in velocity > with the train, and the railway sleepers (rulers) getting > closer together (or apart, George?). The "Old Circular > Logic".......rubber rulers and self-altering clocks Clocks are not self-altering. Clocks are not altered by moving relative to an observer. What is altered is the relationship between the observer and what he is observing. When that relationship is altered, the measurements will be different. You need to read something about relativity. Einstein answered ALL of your objections in his little book. It is a fairly easy read, for the most part. >> Imagine that the train is on a planet orbiting a distant >> star. The train is stopped in the station, but the planet >> is moving with enormous speed relative to Earth. Using the >> SuperMegaHyperTelescope at the top of Mount Everest to view >> inside the train, we see the light beam travel from ceiling >> to floor on a long diagonal path. > > Rubbish! As c'=c+v, the light will travel from its SOURCE at c, > and I will see the beam vertical in the carriage. This is the > same old same! The railcar is moving at high speed relative the observer on Earth. So the beam is travelling on a long, diagonal path relative to the Earth. That is what you argued above. Why is it now rubbish? > dhR's ALWAYS assume c=c+v BEFORE begining even a thought > experiment. It is due to indoctrination! We are trying to find a contradiction in relativity theory, which assumes that the speed of light is constant. If we were trying to find contradictions in Jeff's ad-hoc sock theory, we would assume that the number of socks in the Universe is constant. Showing an internal contradiction when assuming a constant number of socks would disprove my theory. Showing an internal contradiction when assuming a constant speed of light would disprove relativity. Elementary logic. It has nothing to do with relativity. >> It takes the light ten nanoseconds to cover that distance. >> Yet to the person on the train, it takes only seven >> nanoseconds, since it is going straight down from ceiling >> to floor. > > Warning! Do not buy a watch from this person! They have > been altered to give results ONLY in agreement with SR. > When tested, they are checked against a speedometer which > when reading 60mph, show 1 min elapsed every 1500 yards. You assert that the clock must be wrong, but you have not shown that it must be wrong. Show that it must be wrong, and show *why* it must be wrong. >> Which observer is right, and which is wrong? > > They WONT disagree! All their clocks will read the same. Actual measurements show otherwise. > When the photons travel the diagonal (train in motion ref > track) You have forgotten the thought experiment I just set up. I was talking about a train on another planet, stationary on the track. But the planet and train are moving together at enormous speed relative to Earth. So the path of the light is indeed a long diagonal, as seen through the telescope on Mount Everest. > they do so at higher velocity (speed) and so time > taken is the same as for train in the station. Looking through the telescope on Mount Everest, we can see that the speed of the light is just c, even though the light source is moving very fast relative to us. >> Think about it. >> >> >> > Yep! That amazing bulb again, which gives each and every >> >> > emitted photon instruction on which 'speed' to leave at, >> >> > according to whether it is headed forward, down, or >> >> > otherwise. haha >> >> >> >> >> >> > but geometry (pythag) will give the conversion to the >> >> >> > changed photon propagation. >> >> >> >> >> >> I'll let you explain what you had in mind when you wrote >> >> >> that, rather than trying to guess. > > Lazy? Draw a diagram, with photons emitted in all directions > simultaneously; now try it with source in motion. Apparently, all you are saying is that the diagonal path is longer than the straight-down path. Is that right? Did anyone ever disagree with that obvious fact? No. The Pythagorean theorem isn't needed to show it, either. >> >> > A photon emitted directly forward will have velocity c+v >> >> > Others will be subject to vector calculations. Get it now? >> >> >> >> No. Show the geometry and the numbers. Say what you have >> >> in mind instead of just making vague allusions to what you >> >> have in mind. >> >> >> >> >> > NB: no clocks here! or do you wish to call on the photon's >> >> >> > inate sense of the train's speed, and alter it's expulsion >> >> >> > speed from the globe? (Which must be different from those >> >> >> > directed in each different direction lol ) >> >> >> >> >> >> Again, I'll let you explain what you are talking about. >> >> > >> >> > Done and dusted to those who escaped the AE brainwash >> >> >> >> My hope was that you would explain why you think the light >> >> must be moving at different speeds in different directions. >> >> It seems obvious that it must move at different speeds-- >> >> until you try to explain it. You haven't done that. >> > >> > The hypotenuse ceiling to floor is LONGER than the vertical. >> >> Relative to the Earth, but *not* relative to a person on >> the train. >> >> > Therfore, unless the photon is moving at different d/t along >> > those paths, they wouldn't hit floor simultaneously. >> >> You say "the photon is moving" (singular), and "they >> wouldn't hit... simultaneously" (plural). I can't tell >> what things "they" refers to. You clearly are talking >> about multiple things, but what? > > Well unless you have a photon store, you/we can't use the same > photons over; so we'll just have to go with hoping that they > all behave the same. If the behavior differs, the difference will be seen, measured, and become part of a theory. > And as Andro points out, it doesn't matter whether you deal > with a raindrop, photon or whatever. Yes. >> If you mean that the observer in the moving train and an >> observer stationary on the ground could not see a light >> pulse from the ceiling of the train hit the floor at the >> same time, that depends on where the stationary observer >> is located. If he is right beside the train when the light >> reaches the floor, then both observers will see the light >> hit the floor simultaneously. If he is anywhere else, he >> will see it hit the floor later than the person on the >> train. > > see George's comment, and don't obfuscate the situation I didn't know what you meant. It was a reasonable guess. >> However, I don't think the time lag is what you are >> interested in. You are interested in the length of time >> it takes the light to go from ceiling to floor. > > No. What I am interested in, is why AE thinks time has > altered (dilated) when it is perfectly obvious that a > photon has travelled further from its point of origin > in the moving train scenario. (and the passeneger has > twigged it as well) Yes, it is perfectly obvious. The distance the photon moves relative to the observer is greater for an observer who is in motion relative to the train. However, it is unchanged for the observer on the train. And those facts are obvious to both observers. Relativity theory does not say that time alters. What alters is the relationship between an observer and the thing being observed. Time measurements are part of this change. t' = (t-((v/c^2)*x))/SQRT(1-(v^2/c^2)) gives the value of a time measurement in a frame moving wrt the observer. Read any introductory book on relativity. It will explain all of the "whys" from the very beginning. They are, in fact, usually the very *first* things explained. >> The observer on the ground sees the light travel a greater >> distance, and therefore take a longer time to reach the >> floor. >> >> > This is too repetitive- you either get it or not. >> >> I get it. You need to think about it more. >> >> Here is an important question: >> >> What do you think Einstein's special theory of relativity >> is about? Equivalently, why do you think it exists? Why >> did Einstein work it out, and why was it accepted by other >> physicists? > > In a nut, he plaigarised the work of other mistaken (Lorentz) > people, cobbled together self-proving math formula (aforesaid > circular logic), and pulled the greatest con job using unproved > assumptions since certain religions were established Interesting. >> You may have an answer to that question which is different >> from mine, so here is an even more important question, >> which I really hope you will answer: >> >> What do George and I think Einstein's special theory of >> relativity is about? > > I don't know, That is the most telling statement you have made. You don't know what you are arguing about. > and as you two disagree (twist on a towered clock > axle to agree with a clock in space), No, we did not disagree on that. When George said that the axle would twist, that was because he interpreted your description of the scenario to mean that two motors were connected to the axle, and the two motors were not synchronized. I completely agree with what George said. However, you apparently had in mind only a single motor driving the axle, in which case the axle would not twist. That is the scenario I addressed. > I'm not even sure that you are on the same page as he is. I'm not always sure, either, but he usually tells me when I'm wrong, and explains clearly what my error was and helps me to see why I made it. > (Which is why I mentioned clocks when discussing the train > time dilation- George had used that approach, the "observer" > arguement falling down). > It sounded brilliant at the time; remember, no vote was taken > when the king appeared in his magic (read non-existant) cloak, > and everyone "saw" how wonderful it was! Except me (Henri, > Androcles, Spaceman etc) It remains there today, not because > there is a hint of truth in it, but because science abhors a > vacuum, and being unwilling to admit being mislead for so long, > bullishly opposes any attempt to test c=c+v (on which its > foundation depends) Suggest another test, in addition to the vast multitude of tests already accomplished, and if it is feasible, it will be done. But, by the time Maxwell put together the laws of electrodynamics, the fact that the speed of light is constant had already been solidy established. A great deal of electronic devices would function differently from the way they actually do function, if the speed of light were not constant. >> Equivalently, what reason would George and I give to the >> question of why it exists? How would George and I answer >> the question of why Einstein worked it out and why it was >> accepted by other physicists? > > .further up answered I guess that means you don't know what George and I think, even after we have both told you numerous times. >> > When I have more time, I will get back to George with his >> > animation, and see what he can come up with if his clocks >> > tick together, rather than assuming that one WILL do more >> > ticks (no offence George) >> >> You don't understand what the animation shows. If you >> did understand *what* it shows, you would understand >> *why* it shows what it does. > > Don't patronise me! It was I who has pointed out to George > that his clocks are not running as per showing WHY SR time > dilation occurs. Yes. That's how I know that you don't understand what the animation shows. You look at it, and don't understand what you are seeing. George explains it to you again, and you *still* don't understand. > The animation as sent to me (have you actually SEEN it?) No, but George explained it well. > appears to have the clocks running out of sync apriori, > which is using a postulate to "prove" itself. Want to accept > that? Not I! You don't understand what the animation shows. You don't understand *why* the clocks are not synchronized. You don't understand what the animation is intended to show. Even after George explained it to you again. -- Jeff, in Minneapolis (689 lines!)
From: George Dishman on 13 Sep 2005 15:25 <jgreen(a)seol.net.au> wrote in message news:1126564087.777831.76000(a)g43g2000cwa.googlegroups.com... > > George Dishman wrote: >> <jgreen(a)seol.net.au> wrote in message >> news:1126405408.815651.120520(a)f14g2000cwb.googlegroups.com... >> > >> > Jeff Root wrote: >> >> Jim Greenfield replied to Jeff Root: >> ... >> >> I was really just going to ask about the comment >> to me at the bottom but since this is rehashing >> an old conversation with Jim, I'll refresh his >> memory. >> >> >> >> > when train is in motion, by ANY analysis, the ray's direction >> >> >> > is ALTERED- it no longer strikes center. >> >> >> >> >> >> Relative to the world outside the railcar, the ray's >> >> >> direction is altered. Of course, to a person on the >> >> >> railcar, not knowing whether the car is moving, or in >> >> >> which direction or at what speed, the ray's direction >> >> >> is not altered-- it is still going from the ceiling >> >> >> straight down to the floor. >> >> ... and the Earth is moving sideways (whether >> he knows it or not). > > Perhaps- but what is its net motion? I left you paragraph intact because it was all correct, just unfinished. As you said, "to a person on the railcar, .... the ray's direction is not altered-- it is still going from the ceiling straight down to the floor." > The earth rotates, revolves (sun), > the milky way galaxy spins (probably on more than one axis), has > motion ref > other galaxies, globular clusters probably move ref each other......... > the entire visible universe may be a unit moving ref other unseen > 'parts' of the infinity. > So we/you have no idea what the net motion of train or track is. > (and never will :-( ) To the person on the car, the car is not moving but the Earth, Sun, galaxies and clusters are moving. You speak about "net motion" as if it had some other meaning but it just means combining several, for example combining the motion of the galaxies relative to the Sun to that of the Sun relative to the railcar to get the motion of the galaxies relative to the railcar. >> > Rubbish! Read above again to realise that he IS mistaken- and I can >> > prove it! Cut a hole in the floor, and where before the train rider was >> > SURE that the beam is vertical, he actually finds out that he was >> > mistaken/WRONG, when he sees the beam MISS the eaths centre (flat >> > earth) >> >> We went over this many times Jim but you seem to >> have forgotten it all. In the scenario where the >> train is moving, the Earth is moving sideways >> (inertial motion) with the centre directly below >> at the moment the light is emitted so he also >> expects the light to miss the centre. > > If he expects the light to have its path altered (miss the center), > then he also knows that it is travelling a longer path (diagonal). In the first situation, the light moves vertically from the ceiling to the floor and through the hole. It goes on to hit the centre of the Earth which is directly below at all times. In the second scenario, the light moves vertically from the ceiling to the floor and through the hole. At that moment, the centre of the Earth was directly below the hole but moving sideways. The light goes on vertically downwards but the Earth has moved to the side by the time the light gets to where the centre was so it misses. > If he still thinks it will take the same time to reach the floor, then > ergo it is travelling FASTER along the diagonal- UNLESS apriori his > speed measurer (clock) has been tweaked. This is what AE did, and > afraid to say, you as well Why should the fact that the Earth was moving in the second scenario cause the speed of the light between the ceiling and the floor to change? >> >> If he doesn't know whether or how the railcar is moving >> >> relative to the Earth, then he doesn't know where the light >> >> beam will go relative to Earth's center. He will only be >> >> mistaken if he *thinks* he knows how the railcar is moving >> >> relative to the Earth, but is wrong. I'm sure that isn't >> >> the scenario you're interested in. >> > >> > It certainly is! The passenger thinks he is ststionary ref the line at >> > all times, and THAT is why he thinks the beam is VERTICAL at all times. >> > Give him the true situation/information, and he deducts the truth. >> >> He IS stationary and the light IS vertical as >> measured by him, it it the Earth that is moving. >> That is his "truth". > > However you cut it, there IS a difference to the passenger between the > two scenarios. Yes, the difference is that the Earth is moving sideways in one while it is stationary in the other. The railcar is always stationary and the light always moving vertically in both. > Archimedes (?) Did he say that? we call it "Galilean relativity" but my history isn't as good as it should be :-( > reckoned that he had no way of telling whether a ship > was moving if he was in the hold, and denied information from outside > (like our passenger). No, [whoever] reckoned there was no way you could tell even if you _could_ see out because saying "the ship is moving through the sea" and "the sea is moving past the ship" are equivalent descriptions of the same relative motion. > A sudden stop would have told him there was a > change in his velocity, but did the ship hit a reef (was already in > motion, or did it accellerate( assuming he didn't know fore from aft)? Yes, we know acceleration can be detected (in SR or deviation from freefall in GR). > He needed 'Jim's Motion Detector'. This consisits of a monochromatic > light source (set single frequency/wavelength) and a filter which will > allow ONLY that frequ to pass through, the two being constructed in the > same frame. Because c'=c+v, Arch will know when his motion has changed > from that in which the Detector was assembled, when the filter blocks > the beam- the frequency has altered! It won't work since all the components move together, any Doppler shift cancels. Only relative motion produces a change. > Now NASA "knows" this, because they have to alter their filters (read > radio receivers) when the motion of space craft ref earth > alters........ but the AE component subscribes the phenomenon to magic! Different thing, that is relative motion so obviously there is Doppler. In fact the Doppler measured by NASA matches the SR formula anyway so confirms SR. >> > NB that I don't make claim as to what he SEES; ... >> >> All of us I hope are correcting for illusions that >> would be caused by the finite light travel time, we >> really should be past that sort of diversion. > > Can't be done until the passenger speaks in tongues "I am wrong in my > assumptions about my motion, and the motion of the light which I am > "observing!" Oh dear. I said earlier "At that moment, the centre of the Earth was directly below the hole but moving sideways.". I had hoped I didn't need to say that we would only see that happen some time later because of the time it would take for light from the centre to reach the car (assuming the Earth is transparent!) Not only that but you just contradicted what you said about Archimedes. >> >> >> > FYI, this is a CHANGE IN VELOCITY; not only in direction, >> >> >> > which is integral to velocity, >> >> >> >> >> >> Yes the velocity has changed, but only in direction. >> >> >> The magnitude of the velocity (speed) is unchanged. >> > >> > Then it will take longer to reach the floor, as it is travelling a >> > LONGER path. Or doesn't v=d/t?? >> >> "d" and "t" as measured by the passenger >> gives v=c. > > Sure, but if he doesn't know what his motion is, it's wrong. Nope. Speed is defined as distance as measured divided by time as measured. He measures the distance and measures the time and divides and that gives the correct value of speed as per the definition. If you don't like the definition, lobby to have the dictionary changed. That would also rewrite every book on physics of course so I don't think you will succeed. until you do, I will stick with the usual formula. >> > When I have more time, I will get back to George with his animation, >> > and see what he can come up with if his clocks tick together, rather >> > than assuming that one WILL do more ticks (no offence George) >> >> I don't know why you think I would take offence when >> the work I had done was correct, merely unfinished. >> However, which graphic are you talking about, the one >> in which the clocks tick simultaneously illustrates >> Galilean relativity so the speed of the light is not >> c, while the other illustrates SR, the clocks do not >> tick at the same coordinate rates and the speed of >> light is c on all frames as we observe. > > Well, we are stuck, because as Henri points out (and I have asked for > experimental evidence since whenever), experiments as to c'=c+v or > otherwise have NEVER been done! Oh dear Jim, you're not having a good day. Haven't you seen Henri's long threads on binary stars? De Sitter pointed out that this was a test of light from a moving source in 1913, the same year that Sagnac performed his experiment. You know perfectly well that the Sagnac experiment measures the speed of light from a source on a rotating platform because we discussed it at length over last Christmas. That experiment has been done thousands of times and there are commercial devices using it every day.
From: George Dishman on 13 Sep 2005 15:41
<jgreen(a)seol.net.au> wrote in message news:1126592457.877160.318480(a)g43g2000cwa.googlegroups.com... > Jeff Root wrote: >> Jim Greenfield replied to Jeff Root: <big snip> > No. What I am interested in, is why AE thinks time has altered > (dilated) when it is perfectly obvious that a photon has travelled > further from its point of origin in the moving train scenario. > (and the passeneger has twigged it as well) The answer is that AE knew that if the passenger divided the distance masured directly between the bulb and the place the light hit with a ruler at rest in the railcar, and then divided by the time it took measured with a stopwatch also at rest in the car, he would get the value c. It isn't what you or Newton would expect but it is what happens when we do experiments. > I don't know, and as you two disagree (twist on a towered clock axle to > agree with a clock in space), I'm not even sure that you are on the > same page as he is. Jeff and I have different approaches but more importantly you asked a self-contradictory question. We both pointed that out to you. I suspect there may be some differences in our understanding too, nobody's perfect ;-) The key is that he and I can discuss our understanding in a civilised manner and resolve any dispute by reference to known results. You and I were doing that quite well by email last year but you seem to have reverted to a very combative style in the group. It's a shame as I enjoyed our chats. >> You don't understand what the animation shows. If you >> did understand *what* it shows, you would understand >> *why* it shows what it does. > > Don't patronise me! He isn't, he is trying to get you to "watch my lips". Please Jim, read what I say next carefully as you are expecting something that _cannot_ be done and I have explained why many, many times. It was I who has pointed out to George that his > clocks are not running as per showing WHY SR time dilation occurs. The > animation as sent to me (have you actually SEEN it?) appears to have > the clocks running out of sync apriori, which is using a postulate to > "prove" itself. Want to accept that? Not I! Jeff's statement is entirely correct, you don't understand what the animation shows. It is IMPOSSIBLE for me or anyone to "prove" what you ask with an illustration. All it can show is a "what-if" picture. One is "what-if Newton was right". The other is "what-if Einstein was right". The only way to prove one or the other right (or more accurately prove one or more wrong) is to compare the illustrations with real experiments. All the illustrations can prove is self-consistency and we know both models are self-consistent. Do try to understand that Jim, it is getting very tedious explaining it over and over again and if you don't understand it, you will be disappointed if I ever write a full version. At the moment I don't think I will since if I did you would quickly discover it serves no purpose. George |