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Thread: Twin Paradox: Definitive Proof That It's SR?

  1. #1561
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    A similar question

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  2. #1562
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    Quote Originally Posted by Sam5
    HA! Look what I found!!! LOL, Hey! What did I tell you about the Asians! Here’s my “local-ether” theory! [Snip!] THIS IS WHAT I’VE BEEN TELLING YOU GUYS!!! [Links and a great amount of self-congratulatory crowing snipped!]
    Yes, but do you understand the papers that you read as well as you seem to "understand" Einstein's 1905 and 1911 papers? And what about the 1915 paper? Evidently you don't understand that one since you never refer to it, which is too bad since it completely supercedes the 1911 paper.

    As for the notion that it is impossible to get any kind of an ether paper published nowadays, your own link to Professor Su's papers is a clear refutation. I will add to the list a recent paper of Mayeul Arminjon entitled "Ether theory of gravitation: why and how?" (arxiv.org/gr-qc/0401021) Among his references are a number of his and other's papers on the topic. A paper does not have to be mainstream to be published, it just has to be good.

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  4. #1564
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    No posts in over eight hours? Sam5 must be having trouble logging on!

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    Sam, did you read that paper? I don't know what you think it says, but it certainly said nothing about an electromagnetic wave travelling faster than c, regardless of the medium. I see the modification of the Lorentz force law, but what good does that do you for the relative potentials of the fields? I don't see how this gives you VICTORY VICTORY! over those of us who are claiming you don't understand relativity.

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    The basic arguments against SR in this thread were already made years ago in Herbert Dingle's objections, and have long been debunked.

    Ironically, according to physicist Paul Davies, in his book "About Time," professor Dingle also couldn't understand why science continued to accept SR (when applicable) and didn't understand the explanations offered to him for its validity. He eventually assumed there must be a conspiracy among scientists to accept SR. Given the nature and dynamic of scientific thought and competition through the 20th century, and the diversity of personalities within physics alone, such a conspiracy suspicion was also untenable.

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    Sounds about right....

  8. #1568
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    Quote Originally Posted by Chip
    The basic arguments against SR in this thread were already made years ago in Herbert Dingle's objections, and have long been debunked.
    From Chip's link:

    Most modern astrophysicists hold that in fact it was Dingle's reasoning that was faulty; and that his disproof rested on a misunderstanding of the mathematics of special relativity.
    That sure sounds a lot like what's been going on in this thread.

    (Thanks, Chip!)
    Sometimes you win, sometimes you learn

  9. #1569
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    The url which Chip posted, has a link to:

    http://www.mathpages.com/rr/s4-07/4-07.htm

    This page gives an excellent and complete resolution to precisely the question posed on this thread.

    Btw it's very similar to what I wrote earlier on the thread, about GR being needed to identify which frame is inertial (or near inertial) in the Twin Paradox.
    In doing so, it nicely debunks the idea that SR can give a complete explanation of the Paradox.
    (My explanation about acceleration being relative to the global gravity well of the Universe was the same as Weinberg's as it turned out; although I didn't know this at the time I wrote it. So I'm in very good company!)

    However, the link does also conclude that even with GR, you can't necessarily identify which frames are inertial! So some sort of higher theory is needed if we are to totally understand how inertial frames can be picked out.

  10. #1570
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    I've got a couple of minutes here. Will be able to work on posting tomorrow. But, I just couldn't let this go.

    Quote Originally Posted by Sam5
    I showed him the two boxes in the paper a couple of hours ago, so I guess he’s been thinking about them since then. I expect a response soon. As soon as he figures out what Einstein and I are talking about. Then he’ll pretend he “knew it all along”.

    Right now he’s probably stuck on trying to figure out what the “U” clocks are.
    Another shinning example of your guessing and assumptive powers. I'm glad you knew so much about what I was doing that you could insult me while I was dealing with a family member in the hospital.

    You have proved several times over that you don't know what Einstein was talking about (POE, definitions in the 1911 paper, etc)

    As far as pretending to "know it all along", lets take a look at your track record. On Jan 14 on page 52 at 9:05 AM, you posted that you didn't know what c1td and c2ct were. I then pointed out that the definitions were in the paragraph above the diagram. An hour later, on the same page, you started posting that c1dt and c2dt were the speed of light. I corrected you several times that c1dt and c2dt were a distance (the radii of the circles) and that c1 and c2 were the speeds, not c1dt and c2dt. Yet, you continued saying that c1dt and c2dt were speeds. It wasn't until the 17th of Jan. on page 61 that you finally used c1 and c2 as speeds, like you knew "all along" that they were speeds. A good example of power of your understanding.

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    Quote Originally Posted by Tensor
    you started posting that c1dt and c2dt were the speed of light

    I’m sorry, but I don’t understand the point you are trying to make.

    I linked everyone to a physics post website so that everyone could see a representation of Einstein’s 1911 diagram. On that website the designations are c’dt and cdt. The dt represents “far away reference time”. That means a steady time tick rate of a distant clock, because only with a distant clock can we measure the different speed rates of the curving wavefront as it passes the sun, since local atomic clocks would all measure “c” as the light speed at whatever position the clocks are located at. So, if we want to know the actual speeds of the different parts of the turning wavefront, we must use an absolute clock and it must be far enough away from the sun so that the clock is not affected by the sun’s gravitational field.

    I think the confusion was because you were using the c1dt and c2dt, from the book, while I was using the c’dt and cdt from the website. There is also a slightly different version of the same drawing on another website.

    The dt on the website means the c’ and the c are measured by a dt (a distant time clock). We can consider the distance from the sun of the two different parts of the wave front to be anywhere related to the arrows, the c’dt and cdt print, the curves or whatever. This is really not complicated at all.

    We can just say the speed of the light of c’dt on the website means the speed of the wavefront as it passes 100 miles away from the surface of the sun, and the cdt speed is 50 miles from the surface. Or we can say 20 miles and 10 miles. So the c’ and c represent the speed of the wave front at those distances from the surfaces of the sun (say 20 miles and 10 miles), and speed is measured by the dt distant clock. So c’dt is the speed of the light wavefront at that greater distance from the sun and the cdt is the speed of the wavefront at that closer distance to the sun, while the dt represents the distant clock that is measuring the speed. The c1dt and c2dt from the book represent the same thing.

  12. #1572
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    Quote Originally Posted by Einstein
    We obtain the corresponding wave front at time t + dt , or, rather, its line of section with the plane of the paper, by describing circles round the points P1 and P2 with radii c1 dt and c2 dt respectively, where c1 and c2 denote the velocity of light at the points P1 and P2 respectively, and by drawing the tangent to these circles
    Sounds to me like dt is calculus talk for an infinitesimally small time after t, making cdt et al distances, since they are integrands (or differentials and then integrands). I don't know where the confusion is if you know the math...

  13. #1573
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    The dt on the website means the c’ and the c are measured by a dt (a distant time clock).
    [-X [-X [-X

    Sam5, You have just proved that you not only do not understand SR, but that you do not even have a grasp of 1st semester calculus!

    :roll: :roll: :roll:

    dt is the derivative with respect to time!

    dt = a distant time clock


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    I tried to say it nicely....

  15. #1575
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    So Sam, you think that Lorentz's theory that time changes so that light will always be measured at c is a good theory? Do you think it is a testable theory or just handwaving to explain the Michelson-Morley failures?

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    If you say it nicely, he ignores you. If you put it bluntly, he calls you a troll.

    Ya pays yer money, ya takes yer chances! 8-[

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    Oh yeah, are you still certain that the Twin paradox is impossible? Because I think I found an explaination.

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    Quote Originally Posted by alexh110
    Btw it's very similar to what I wrote earlier on the thread, about GR being needed to identify which frame is inertial (or near inertial) in the Twin Paradox.
    In doing so, it nicely debunks the idea that SR can give a complete explanation of the Paradox.
    (My explanation about acceleration being relative to the global gravity well of the Universe was the same as Weinberg's as it turned out; although I didn't know this at the time I wrote it. So I'm in very good company!)
    The "Twin Paradox" thought-experiment in Einstein's 1905 paper takes place in an idealized universe in which there is no gravity. All the frames of reference are perfectly inertial. But one of the twins must undergo an acceleration because he switches from one inertial frame to another during the course of the experiment!

    By the way, if you define an inertial frame as one in which Newton's First Law of Motion is perfectly obeyed, then you can determine whether your frame in inertial (within the limits of observation) by carrying out some experiments.

    If you want to work out which twin ends up younger and by how much, all you need is SR. If, however, you want to explain why this is the case, then no theory will suffice - because "Why?" is a metaphysical question, not a scientific one.

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    I personally prefer the 3-frame explanation - it avoids any calculations involving acceleration, and simply measures 'total travel time'. It also explains why a first glance would indicate that there's a paradox, where none exists.

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    Quote Originally Posted by [url=http://www.badastronomy.com/phpBB/viewtopic.php?p=194213#194213
    Sam5[/url]]
    Quote Originally Posted by milli360
    I'm surprised that you persist in using that 1911 paper in justifying your position. It appears to disagree with GR even.
    It is GR. What do you mean it disagrees with GR. I think the 1911 paper is the main GR paper, just about the only part of GR that Einstein didn't have to recall.
    As I've said, I haven't read the 1911 paper. But Einstein did not publish his general relativity until 1915, so any 1911 paper, or any of 1914 or before, is not the main GR paper. There are going to be parts that disagree with GR. Just like SR and Newton's theory disagrees with GR.
    Quote Originally Posted by [url=http://www.badastronomy.com/phpBB/viewtopic.php?p=194231#194231
    Sam5[/url]]
    Quote Originally Posted by milli360
    But, the 1911 is probably out and out wrong,
    LOL, I get it now. You don't like it because it shows the speed of light slowing down, speeding up, and not being "constant". LOL
    No, because I haven't read the paper.
    Quote Originally Posted by [url=http://www.badastronomy.com/phpBB/viewtopic.php?p=194232#194232
    Sam5[/url]]
    Quote Originally Posted by milli360
    But, the 1911 is probably out and out wrong,
    So you think Einstein was WRONG!? Are you some kind of crank or crackpot?
    Everyone makes errors. But anyone who studies relativity for over a decade, refuses to learn basic calculus, and insists that they understand relativity well enough to detect fundamental errors that physicists are unable to understand, is a crackpot. The crackpot may even be right, but they are still a crackpot. And there is nothing wrong with that, some of my best friends are crackpots.

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    Quote Originally Posted by Sam5
    swansont,

    Maybe you can look it up in the HK papers. Their westbound clock speeded up. 1905 SR clocks only slow down.
    Have you actually looked at the Hafele-Keating experiment? Clocks on the surface of the earth are moving. A westbound clock moves more slowly, and so speeds up relative to a clock on the ground.

    This is conceptually no different than saying the clocks moving to a weaker gravitational field speed up, which you have done a number of times.

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    Quote Originally Posted by swansont
    Quote Originally Posted by Sam5
    swansont,

    Maybe you can look it up in the HK papers. Their westbound clock speeded up. 1905 SR clocks only slow down.
    Have you actually looked at the Hafele-Keating experiment? Clocks on the surface of the earth are moving. A westbound clock moves more slowly, and so speeds up relative to a clock on the ground.

    I’ve got their papers right here. Why don’t you get out your copies and we’ll compare them.

    I’ve tried to explain this several times. But nobody has the books, nobody’s read the papers, etc., etc.. People quickly do google searches and they pick up science urban legends and they think they know “relativity theory” in depth.

    In 1905 SR theory the clocks slow down in all directions of travel because of “relative motion”.

    In 1895 and 1904 Lorentz theory clocks slow down the faster they travel through fields. They slow down less if they travel through fields at a slower rate.

    The H-K experiment proved the Lorentz theory, not the 1905 Einstein theory.

  23. #1583
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    Quote Originally Posted by milli360
    But anyone who studies relativity for over a decade, refuses to learn basic calculus, .
    I don’t understand how someone who has a twins paradox resolution on the internet can go so long without ever reading the 1911 gravitational redshift theory.

    There is no more Kinematical part of the SR theory. Einstein changed the light speed postulate in 1911 and he changed the cause of the clock slowdown in SR from “relative motion” to “gravitational field” in 1918.

    This information is not very well know, even by a lot of physics professors.

    Here’s what Pauli said about it in 1921:

    ”Equation [Delta t/t’= - (Phi/c^2)] has the following physical meaning: Consider two equal, originally synchronous, clocks at rest and let one of them be placed in a gravitational field for a certain length of time. Afterwards they will no longer be synchronous; the clock which had been placed in the gravitational field will have lost. As mentioned by Einstein [A. Einstein, Naturwissenschaften, 6 (1918) 697], this is the basis of the explanation for the clock paradox described in [section 5 of this book]. In the coordinate system k in which the clock C2 is permanently at rest, a gravitational field exists during the time in which its motion is retarded, and the observer in k can regard this field as causing the clock C2 to lose.”

    See? The equation is based on the same one that’s in the 1911 paper.

    Einstein might not have named the General Theory until 1916, but the 1911 paper is one of his earliest pure GR theory papers.

    In a 1916 paper he said, “...the special theory of relativity applies to the special case of the absence of a gravitational field.”

    And as I just pointed out, Pauli said he added the gravitational field to the Kinematical part of the SR theory in 1918, and I’ve got a copy of the 1918 theory on order. So, as of 1918, there was no more SR theory, since everywhere in space there is a gravitational field, some weak, some strong, but everywhere they exist, and they control the speed of light, and as of 1911 the speed of light in Einstein theory was variable in different parts of space. That's why he said in his book in 1916:

    "A curvature of rays of light can only take place when the velocity of propagation of light varies with position."

  24. #1584
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    Quote Originally Posted by Eroica
    The "Twin Paradox" thought-experiment in Einstein's 1905 paper takes place in an idealized universe in which there is no gravity. All the frames of reference are perfectly inertial. But one of the twins must undergo an acceleration because he switches from one inertial frame to another during the course of the experiment!
    There is an alternative explanation, which is the correct one. The clock paradox thought experiment and the slowdown due only to “relative motion” in the 1905 paper is simply a mistake, which he corrected in 1918. He realized it was a mistake, and that’s why he added the gravitational field to the k frame in 1918. He had physicists on his back all over Europe about this, and that’s why he was forced to add the gravitational field to the SR theory in 1918. This is science history that you guys need to study.

  25. #1585
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    Quote Originally Posted by Sam5
    There is no more Kinematical part of the SR theory. Einstein changed the light speed postulate in 1911 and he changed the cause of the clock slowdown in SR from “relative motion” to “gravitational field” in 1918.
    No, he added the gravitational field cause. He never removed the relative motion.

    Quote Originally Posted by Sam5
    In a 1916 paper he said, “...the special theory of relativity applies to the special case of the absence of a gravitational field.”
    Isn't that what we've been saying? You've been arguing that SR doesn't apply ever.

    Quote Originally Posted by Sam5
    The clock paradox thought experiment and the slowdown due only to “relative motion” in the 1905 paper is simply a mistake, which he corrected in 1918. He realized it was a mistake, and that’s why he added the gravitational field to the k frame in 1918.
    Okay, I'm going to ask this again. If you think Einstein was correct in 1918, then answer this question:

    If two clocks are out in intergalactic space, motionless relative to each other at a distance of h, and then one clock is accelerated towards the other at a rate of y, what is the GR equation that predicts the amount of clock slowdown?
    Sometimes you win, sometimes you learn

  26. #1586
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    Quote Originally Posted by alexh110
    Btw it's very similar to what I wrote earlier on the thread, about GR being needed to identify which frame is inertial (or near inertial) in the Twin Paradox.
    In doing so, it nicely debunks the idea that SR can give a complete explanation of the Paradox.
    I don't understand this, alex. The twin paradox does not require any non-inertial frame. Whether in Einstein's original 1905 "peculiar consequence," or in the more oft-stated "Twin A rockets away and returns," both twins are in inertial frames the entire time - one of them just doesn't stay in the same inertial frame.
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    You're not still on this, are you?

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    Quote Originally Posted by SeanF
    No, he added the gravitational field cause. He never removed the relative motion.
    But by adding the gravitational field to the k frame to make the clock slow down (and of course it became an atomic clock, no longer a mechanical clock), the relative motion did nothing to the clock, it was the gravity field that slowed it down. So, there doesn't need to be any "relative motion" in the theory any more, since as of 1918 it was the gravity field, not the motion, that slowed down the clock.

    Quote Originally Posted by SeanF
    Okay, I'm going to ask this again. If you think Einstein was correct in 1918, then answer this question:

    If two clocks are out in intergalactic space, motionless relative to each other at a distance of h, and then one clock is accelerated towards the other at a rate of y, what is the GR equation that predicts the amount of clock slowdown?
    I'm not sure what the modern formula is, but I'm sure you can look it up on the internet if you need to know it. In 1921, one version Pauli gave in his book was [Delta t/t’= - (Phi/c^2)] This was for atomic clocks only, not mechanical or pendulum clocks, and this was his gravity-caused slowdown, but in modern formulas, I don't know if they make a distinction between motion related acceleration and gravity acceleration or not.

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    Quote Originally Posted by Sam5
    Quote Originally Posted by SeanF
    Okay, I'm going to ask this again. If you think Einstein was correct in 1918, then answer this question:

    If two clocks are out in intergalactic space, motionless relative to each other at a distance of h, and then one clock is accelerated towards the other at a rate of y, what is the GR equation that predicts the amount of clock slowdown?
    I'm not sure what the modern formula is, but I'm sure you can look it up on the internet if you need to know it. In 1921, one version Pauli gave in his book was [Delta t/t’= - (Phi/c^2)] This was for atomic clocks only, not mechanical or pendulum clocks, and this was his gravity-caused slowdown, but in modern formulas, I don't know if they make a distinction between motion related acceleration and gravity acceleration or not.
    My point is you are claiming Einstein was right by this point, but you don't even know what Einstein said! How can you do that? If you believe that Einstein came up with a valid theory for the slowdown of an accelerating atomic clock, then you should be able to give the equation.
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    Quote Originally Posted by SeanF
    I don't understand this, alex. The twin paradox does not require any non-inertial frame. Whether in Einstein's original 1905 "peculiar consequence," or in the more oft-stated "Twin A rockets away and returns," both twins are in inertial frames the entire time - one of them just doesn't stay in the same inertial frame.
    Pauli said in 1921 that Einstein removed all considerations of frame change and acceleration due to motion. He specifically said:

    “If we take the special case where C2 is moved along the x-axis to a point Q and then back again to P, with discontinuous velocity changes at P and Q, then the effect of the acceleration will certainly be independent of t and can easily be eliminated. The paradox now lies in the following statement: Let us describe the process in terms of a reference system k, always at rest with respect to C2. Clock C1 will then move relative to k in the same way as C2 moves relative to K. Yet, at the end of the motion, Clock C2 will have lost compared with C1, i.e. C1 will have gained compared with C2. The paradox is resolved by observing that the coordinate system k is not a Galilean reference system and that in such a system the effect of acceleration cannot be neglected, since the acceleration is not produced by an external force, but, in the terminology of Newtonian mechanics, by an inertial force.”

    Then he says:

    ”Equation [Delta t/t’= - (Phi/c^2)] has the following physical meaning: Consider two equal, originally synchronous, clocks at rest and let one of them be placed in a gravitational field for a certain length of time. Afterwards they will no longer be synchronous; the clock which had been placed in the gravitational field will have lost. As mentioned by Einstein [A. Einstein, Naturwissenschaften, 6 (1918) 697], this is the basis of the explanation for the clock paradox described in [section 5 of this book]. In the coordinate system k in which the clock C2 is permanently at rest, a gravitational field exists during the time in which its motion is retarded, and the observer in k can regard this field as causing the clock C2 to lose.”

    So, he disregards start-up and turn-around motion related acceleration and he adds gravitational acceleration to the 1905 SR theory.

    Then he says:

    ”Of course, a complete explanation of the problem can only be given in the framework of the general theory of relativity...”

    So, by 1918 Einstein realized that the SR “relative motion” theory did not work and that “relative motion” alone would not slow down clocks. So he added gravitation to the k frame and he made the clock an atomic clock, as per his 1911 theory. So, SR is wrong and it no longer applied after 1918, and “relative motion” alone can not slow down any clock.

    You need to read the contemporary explanations, not the modern ones off of internet websites. The original explanations tell us what Einstein and his physicist supporters thought back in that original era. The modern internet opinions will give you hundreds of different things about what grocery clerks, security guards, geologists, housewives, and taxi drivers think.

    Your idea that something happens at “turn around” time was just not considered by Einstein or Pauli. You must have gotten that idea off a modern website.

    I don’t understand why you don’t buy some of these old books and study them.

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