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Thread: How can 299792458 m/s be different to 299792458 m/s ?

  1. #1 How can 299792458 m/s be different to 299792458 m/s ? 
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    We were talking about this in a thread that was rather spoilt by bad behaviour. I think it's an important point, perhaps we can tease it out:

    Quote Originally Posted by KJW
    How can 299792458 ms1 be different to 299792458 ms1? Same numerical value, same units, that is a rather strange definition of "different".
    One 299792458 ms1 can be different to another 299792458 ms1 when the seconds are different. It's that simple. If you're lower than me your seconds are bigger than mine. So your 299792458 ms1 is slower than mine. Note that your metres are the same as my metres, because your slower light and your bigger second cancel each other out. Hence we have the parallel-mirror gif which is an idealisation of the NIST optical clocks:


    Image credit: Brian McPherson

    The speed of light between the upper pair of mirrors is 299792458 ms1. The speed of light between the lower pair of mirrors is 299792458 ms1. But the two speeds are not the same because the seconds aren't the same. If they were really the same, the clocks would stay synchronised, and they don't. The thing to appreciate is that there is no time flowing anywhere. All a clock does is accumulate some kind of regular cyclic motion and show a cumulative result called the time. When a clock goes slower it's because that motion goes slower.
    Last edited by Farsight; 09-06-2014 at 03:46 PM. Reason: Removed spurious from speeds in title
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    So you're saying that there is one real standard that hides behind the apparent standard.
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    No, I'm saying the constant speed of light is a tautology, like Magueijo and Moffat said in [0705.4507] Comments on "Note on varying speed of light theories" :

    "Following Ellis [1], let us first consider c as the speed of the photon. Can c vary? Could such a variation be measured? As correctly pointed out by Ellis, within the current protocol for measuring time and space the answer is no. The unit of time is defined by an oscillating system or the frequency of an atomic transition, and the unit of space is defined in terms of the distance travelled by light in the unit of time. We therefore have a situation akin to saying that the speed of light is one light-year per year, i.e. its constancy has become a tautology or a definition."

    It's constant by definition, because we use the local motion of light to define the second and the metre, then we use them to measure the local speed of light. So we always say it's 299792458 m/s. It's like saying racehorses always run at 40mph, because wherever you are, you defined the mile and the hour using a racehorse running.
    Last edited by Farsight; 09-06-2014 at 03:46 PM.
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    You appear to be saying something quite different from them.

    If they really are referring to Ellis, then they are referring to the idea that the theory tells us that there is no physical difference between the speed in any possible scenario. (You might want to read your reference and the Ellis paper that they reference.) You, on the other hand, are telling us that there is a physical difference that is merely hidden. You are showing us a gif that tells us that there really is a difference, just one that we can never detect. Nonetheless, you believe that this difference exists despite the evidence.

    Perhaps you would like to show us the relevant mathematical physics that justifies the use of that gif?
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    Quote Originally Posted by Farsight View Post
    One 299792458 ms1 can be different to another 299792458 ms1 when the seconds are different. It's that simple.
    No, it's not that simple.

    If one measures the same velocity, one measures the same velocity. That is what is "that simple."

    You are claiming that, despite an experimental determination of equal velocities, there is nonetheless somehow a difference. But if that difference does not appear in any experiment, it is not a part of objective reality. It therefore follows that you are making claims about a "reality" that is inaccessible to experiment, and thus about a matter that is beyond science.
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    Quote Originally Posted by Farsight View Post
    One 299792458 ms1 can be different to another 299792458 ms1 when the seconds are different. It's that simple.
    Unfortunately, it's not that simple because you've just shifted the problem from 299792458 ms1 being different to 299792458 ms1 to 1 s being different to 1 s. The point I'm making is that in order for the notion of difference to be in any way meaningful, the difference has to be represented in some way. You have presented that GIF on a number of occasions to indicate differences in the speed of light, but that GIF is nothing more than a cartoon and doesn't represent anything that is real. Therefore, you need some other way to represent the differences between two things that are ostensibly the same. In other words, without resorting to the GIF, precisely how is one 299792458 ms1 different to another 299792458 ms1
    A tensor equation that is valid in any coordinate system is valid in every coordinate system.
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    Quote Originally Posted by Farsight View Post
    The speed of light between the upper pair of mirrors is 299792458 ms1. The speed of light between the lower pair of mirrors is 299792458 ms1. But the two speeds are not the same because the seconds aren't the same. If they were really the same, the clocks would stay synchronised, and they don't. The thing to appreciate is that there is no time flowing anywhere. All a clock does is accumulate some kind of regular cyclic motion and show a cumulative result called the time. When a clock goes slower it's because that motion goes slower.
    It looks like you could just as easily draw the diagram with the space wider in the bottom picture and the speed of the photon the same. The clock would still run slower. What is the advantage of one picture over the other?

    In other words does gravity distort space or time?
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    Quote Originally Posted by PhysBang
    You appear to be saying something quite different from them.
    No I'm not, and you know it.

    Quote Originally Posted by PhysBang
    If they really are referring to Ellis, then they are referring to the idea that the theory tells us that there is no physical difference between the speed in any possible scenario. (You might want to read your reference and the Ellis paper that they reference.)
    I've read the papers, Magueijo and Moffat make it clear that it's a tautology.

    Quote Originally Posted by PhysBang
    You, on the other hand, are telling us that there is a physical difference that is merely hidden. You are showing us a gif that tells us that there really is a difference, just one that we can never detect. Nonetheless, you believe that this difference exists despite the evidence.
    I'm saying the difference is patent. Clocks run slower when they're lower. Light goes slower near the Sun.

    Quote Originally Posted by PhysBang
    Perhaps you would like to show us the relevant mathematical physics that justifies the use of that gif?
    You know I've done it previously. It's the maths you're already familiar with. Such as:




    ...wherein t0 is a count of the number of reflections in a parallel-mirror light clock, and so is tf.



    Quote Originally Posted by tk421 View Post
    No, it's not that simple.
    It is. Really.

    Quote Originally Posted by tk421
    If one measures the same velocity, one measures the same velocity. That is what is "that simple."
    And wrong. Because you define your second and your metre using the local motion of light, then use them to measure the local motion of light. So of course you measure the same speed. Even when those speeds are patently different. This is tautology Magueijo and Moffat were talking about.

    Quote Originally Posted by tk421 View Post
    You are claiming that, despite an experimental determination of equal velocities, there is nonetheless somehow a difference.
    Yes.

    Quote Originally Posted by tk421 View Post
    But if that difference does not appear in any experiment, it is not a part of objective reality.
    It does, and it is. Have a look at the Shapiro delay:

    "The proposed experiment was designed to verify the prediction that the speed of propagation of a light ray decreases as it passes through a region of decreasing gravitational potential:"

    And the NIST optical clocks go slower when they're lower. Because the light goes slower when its lower. It's definitely appears in experiment and is patently a part of objective reality. Why on Earth did you ever think it wasn't?

    Quote Originally Posted by tk421 View Post
    It therefore follows that you are making claims about a "reality" that is inaccessible to experiment, and thus about a matter that is beyond science.
    Not so.



    Quote Originally Posted by KJW
    Unfortunately, it's not that simple because you've just shifted the problem from 299792458 ms1 being different to 299792458 ms1 to 1 s being different to 1 s.
    It really is that simple. We call it gravitational time dilation, but there is no light flowing in an optical clock. If you claim that there is, and that time flows slower when the clock is lower, then you are making claims about something that does not appear in any experiment, and is not a part of objective reality.

    Quote Originally Posted by KJW
    The point I'm making is that in order for the notion of difference to be in any way meaningful, the difference has to be represented in some way. You have presented that GIF on a number of occasions to indicate differences in the speed of light, but that GIF is nothing more than a cartoon and doesn't represent anything that is real. Therefore, you need some other way to represent the differences between two things that are ostensibly the same. In other words, without resorting to the GIF, precisely how is one 299792458 ms1 different to another 299792458 ms1.
    One is slower than the other. Hence one NIST optical clock goes slower than the other. When it's 30cm lower. It really is that simple.



    Quote Originally Posted by Jilan
    It looks like you could just as easily draw the diagram with the space wider in the bottom picture and the speed of the photon the same. The clock would still run slower. What is the advantage of one picture over the other?
    The picture as shown faithfully depicts the way the "coordinate" speed of light varies with gravitational potential, and the absence of non-radial length contraction. Note that a wider space in the bottom picture would not be a length contraction.

    Quote Originally Posted by Jilan
    In other words does gravity distort space or time?
    Wrong question. A concentration of energy "conditions" the surrounding space altering its "metrical" qualities. It doesn't actually distort the space, it makes it inhomogeneous, the affect diminishing with distance in line with 1/r. So when you select a series of locations and take measurements using say light clocks then plot your measurements, your plot is curved. Space isn't curved, your metric is curved. And because of this, light curves and matter falls down. We call the effect gravity, but the cause is the concentration of energy. That's what "distorts time". But remember that time is just some cumulative measure of cyclical local motion "clocked up" and displayed by the device we call a clock.
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    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by KJW
    Unfortunately, it's not that simple because you've just shifted the problem from 299792458 ms1 being different to 299792458 ms1 to 1 s being different to 1 s.
    It really is that simple. We call it gravitational time dilation, but there is no light flowing in an optical clock. If you claim that there is, and that time flows slower when the clock is lower, then you are making claims about something that does not appear in any experiment, and is not a part of objective reality.
    All I'm saying is that 299792458 ms1 is the same as 299792458 ms1 and 1 s is the same as 1 s. It is up to you to specify how they are not (not why they are not, btw). Your reply doesn't address the question that I am asking and appears to me to be a diversion.


    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by KJW
    The point I'm making is that in order for the notion of difference to be in any way meaningful, the difference has to be represented in some way. You have presented that GIF on a number of occasions to indicate differences in the speed of light, but that GIF is nothing more than a cartoon and doesn't represent anything that is real. Therefore, you need some other way to represent the differences between two things that are ostensibly the same. In other words, without resorting to the GIF, precisely how is one 299792458 ms1 different to another 299792458 ms1.
    One is slower than the other. Hence one NIST optical clock goes slower than the other. When it's 30cm lower. It really is that simple.
    No, that is not enough. I asked for precision. For example, you tell me one is slower than the other, but by how much? Can the difference be measured and be quantified?

    Btw, I do understand the nature of gravitational time dilation, and your explanation of it does not match my understanding of it. Thus, while I do not deny the existence of time dilation effects, I do deny the inferences you make concerning it.
    A tensor equation that is valid in any coordinate system is valid in every coordinate system.
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    Quote Originally Posted by Farsight View Post
    No I'm not, and you know it.
    Apparantly not only I don't knwo it, but nobody else reading your words knows it either. You need to produce a serious derivation that explains what you mean.
    I've read the papers, Magueijo and Moffat make it clear that it's a tautology.
    The reference of Magueijo and Moffat is in the context of referring to Ellis; Ellis does not use the word "tautology". Rather he discusses the detailed relationships between the speed of light and many theories. He then explains in detail why a so-called variable speed of light theory involves the breaking of Lorentz symmetry. You seem to mean something different, so you should walk us through the mathematical details.
    I'm saying the difference is patent. Clocks run slower when they're lower. Light goes slower near the Sun.
    According to GR, we are free to say that they run at the same speed and that light goes the same speed at every point. It would be interesting to see your theory with light having a different speed at different points, and it would be required to see it to understand your claims.
    You know I've done it previously.
    No, at no time have you ever produced mathematical details sufficient to explain your gif.
    It's the maths you're already familiar with. Such as:




    ...wherein t0 is a count of the number of reflections in a parallel-mirror light clock, and so is tf.
    This is far, far from sufficient; you are only producing equations without context or specifications. You need to at least fill out the details with some choices for the conditions of the mirrors, e.g., where they are, how far apart they are, the mass that is near them, the distances from the center of mass, and so on. We need to see the Farsight Theory calculation for why the light is actually going slower at every location.
    It is [simple]. Really.
    Unfortunately, you are wrong, you cannot simple wave a gif around and cut and paste an equation to explain what you mean. It is understandable and straight-forwardly understandable for you to produce an example with chosen measurement details that use the mathematics of the theory to explain its kinematics and dynamics.

    As it stands, you are making a claim that there is a fact of the matter that certain speeds are not representative, that they are slowed relative to an unknowable standard. You need to explain this with some detail.
    It really is that simple. We call it gravitational time dilation, but there is no light flowing in an optical clock. If you claim that there is, and that time flows slower when the clock is lower, then you are making claims about something that does not appear in any experiment, and is not a part of objective reality.
    There are many things that do not appear to vision that are part of experiments. For example, the gravitational constant does not appear to vision, yet we believe very strongly in the existence of this abstract entity (or rather, we should, in whatever fashion it is correct to believe in this abstract entity). We have many ways of measuring time and no way to make a physics experiment without making reference to time.

    If you can describe a physics scenario of the kind you are describing without time, please do so.

    One is slower than the other. Hence one NIST optical clock goes slower than the other. When it's 30cm lower. It really is that simple.
    You have not yet demonstrated a convincing explanation for this phenomenon. GR, on the other hand, seems to have a satisfactory explanation that matches the numbers that we measure. You are offering us an explanation little better than saying that fairies slow down these clocks: it can match the facts, but seemingly for an arbitrary reason without real explanation or robust predictability or extension to other cases.
    Wrong question. A concentration of energy "conditions" the surrounding space altering its "metrical" qualities. It doesn't actually distort the space, it makes it inhomogeneous, the affect diminishing with distance in line with 1/r. So when you select a series of locations and take measurements using say light clocks then plot your measurements, your plot is curved. Space isn't curved, your metric is curved. And because of this, light curves and matter falls down. We call the effect gravity, but the cause is the concentration of energy. That's what "distorts time". But remember that time is just some cumulative measure of cyclical local motion "clocked up" and displayed by the device we call a clock.
    Now you will have to demonstrate how inhomogeneous 3D euclidean space (without any time) can generate motion similar to those that we observe. It seems doubtful that you can recover Newtonian mechanics with such a schema, but let's see the mathematics.
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    Take a look at the title of your OP. Meters per second squared?????? Twice???
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    Quote Originally Posted by KJW View Post
    All I'm saying is that 299792458 ms1 is the same as 299792458 ms1 and 1 s is the same as 1 s. It is up to you to specify how they are not (not why they are not, btw). Your reply doesn't address the question that I am asking and appears to me to be a diversion.
    It's no diversion. You know that a clock runs slower when its lower. You know that everything runs slower when it's lower, including you. You know that we call this phenomenon gravitational time dilation. You know that a second lasts longer when time dilation is occurring. Surely? This is something you should be totally familiar with and comfortable with. You should be familiar and comfortable with the why of it too: a concentration of energy "conditions" the surrounding space, altering its metrical properties. This is what Einstein said. The only departure you need to make from what you think you know is this: there isn't any time flowing in a clock. Try to be scientific about this and think about what a clock actually does: it always features some kind of regular cyclical motion. If you open up a mechanical clock you can see it happening. It's empirical. But you can't see any time flowing through it. So the clock goes slower because the motion goes slower. Even when its a light clock.

    Quote Originally Posted by KJW View Post
    No, that is not enough. I asked for precision. For example, you tell me one is slower than the other, but by how much? Can the difference be measured and be quantified?
    Of course it can. The NIST optical clocks demonstrate a measurable difference when one is only 30cm above the other, see the David Wineland interview. And the GPS clock adjustment is well understood, see Wiki. There's an SR adjustment and a GR adjustment, the latter being greater. The clock is set to run slow so once it's up in orbit it's running faster, at the right rate. NB: note the mention of Friedwardt Winterberg there. He was in on the ground floor of GPS.

    Quote Originally Posted by KJW View Post
    Btw, I do understand the nature of gravitational time dilation, and your explanation of it does not match my understanding of it. Thus, while I do not deny the existence of time dilation effects, I do deny the inferences you make concerning it.
    Like I said above, all you have to do is open up a clock and remind yourself that there's isn't any literal time flowing through it. It merely clocks up some kind of regular cyclical motion and shows you a cumulative display that you call the time. This is what A World without Time: The Forgotten Legacy of Godel and Einstein is all about. It might help if you read the time travel is a fantasy OP.
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    Quote Originally Posted by PhysBang View Post
    The reference of Magueijo and Moffat is in the context of referring to Ellis; Ellis does not use the word "tautology".
    But Magueijo and Moffat do.

    Quote Originally Posted by PhysBang View Post
    Rather he discusses the detailed relationships between the speed of light and many theories. He then explains in detail why a so-called variable speed of light theory involves the breaking of Lorentz symmetry. You seem to mean something different, so you should walk us through the mathematical details.
    I mean what Einstein said, which is that a curvature of rays of light can only occur when the speed of light varies with position. Lorentz symmetry is a red herring.

    Quote Originally Posted by PhysBang View Post
    According to GR, we are free to say that they run at the same speed and that light goes the same speed at every point.
    No you aren't, because you're contradicting Einstein and walking into the tautology. The GR you are ascribing to is an ersatz version of GR.

    Quote Originally Posted by PhysBang View Post
    It would be interesting to see your theory with light having a different speed at different points, and it would be required to see it to understand your claims.
    It isn't my theory. I wasn't the guy who said a curvature of rays of light can only occur when the speed of light varies with position. It was another guy. Nearly a hundred years ago.

    Quote Originally Posted by PhysBang View Post
    No, at no time have you ever produced mathematical details sufficient to explain your gif.
    I just told you, t is a count of reflections. That explains it enough.

    Quote Originally Posted by PhysBang View Post
    This is far, far from sufficient; you are only producing equations without context or specifications. You need to at least fill out the details with some choices for the conditions of the mirrors, e.g., where they are, how far apart they are, the mass that is near them, the distances from the center of mass, and so on. We need to see the Farsight Theory calculation for why the light is actually going slower at every location.
    It's like Einstein said, space is conditioned by matter, altering its metrical qualities.

    Quote Originally Posted by PhysBang View Post
    Unfortunately, you are wrong, you cannot simple wave a gif around and cut and paste an equation to explain what you mean. It is understandable and straight-forwardly understandable for you to produce an example with chosen measurement details that use the mathematics of the theory to explain its kinematics and dynamics. As it stands, you are making a claim that there is a fact of the matter that certain speeds are not representative, that they are slowed relative to an unknowable standard. You need to explain this with some detail.
    No, I don't. All I need to do is point to what Einstein said and what Don Koks and Ned Wright and Irwin Shapiro said, and point out that there isn't any literal time flowing through a clock.

    Quote Originally Posted by PhysBang View Post
    There are many things that do not appear to vision that are part of experiments. For example, the gravitational constant does not appear to vision, yet we believe very strongly in the existence of this abstract entity (or rather, we should, in whatever fashion it is correct to believe in this abstract entity). We have many ways of measuring time and no way to make a physics experiment without making reference to time. If you can describe a physics scenario of the kind you are describing without time, please do so.
    I can't, nobody can. But I can point out that time isn't something that literally flows.

    Quote Originally Posted by PhysBang View Post
    You have not yet demonstrated a convincing explanation for this phenomenon. GR, on the other hand, seems to have a satisfactory explanation that matches the numbers that we measure. You are offering us an explanation little better than saying that fairies slow down these clocks: it can match the facts, but seemingly for an arbitrary reason without real explanation or robust predictability or extension to other cases.
    No, you're the one who believes in fairies. You believe a clock measures the flow of time. It doesn't. That's just a figure of speech.

    Quote Originally Posted by PhysBang View Post
    Now you will have to demonstrate how inhomogeneous 3D euclidean space (without any time) can generate motion similar to those that we observe. It seems doubtful that you can recover Newtonian mechanics with such a schema, but let's see the mathematics.
    As I've said repeatedly, the mathematics is the same.
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    Quote Originally Posted by Farsight View Post
    But Magueijo and Moffat do.
    Sure, but you can't ignore the content of what they are referring to. You claim to have read Ellis, but you then dismiss everything that he writes without comment or reason.
    I mean what Einstein said, which is that a curvature of rays of light can only occur when the speed of light varies with position.
    You actually say that the speed of light varies with position which causes curvature, but without any details. This is a reverse of what Einstein actually says (sufficient vs necessary conditions) and you seem to violate the details that Einstein wrote into the mathematics. This is why you should produce the details that you have, so far, not provided.
    Lorentz symmetry is a red herring.
    Again you dismiss the entire content of Ellis' paper and the subsequent expansion upon it that Magueijo and Moffat do. Again without apparent justification.
    No you aren't, because you're contradicting Einstein and walking into the tautology. The GR you are ascribing to is an ersatz version of GR.
    If you believe so, then the onus is on you to show the true details. These details are apparently ones that Einstein never wrote down mathematically, so you will have to provide these mathematical details.
    It isn't my theory. I wasn't the guy who said a curvature of rays of light can only occur when the speed of light varies with position. It was another guy. Nearly a hundred years ago.
    But you disagree with both the conditional nature of his statement and his mathematical details, therefore you are presenting what appears to be a special theory that is wholly your own. If you can produce the mathematical details, then we can see if there is a difference.
    I just told you, t is a count of reflections. That explains it enough.
    Contemporary physicists have a very specific means of discussing these types of phenomena that goes well beyond this and matches the available evidence. If you have nothing better, then I'm afraid that on the measurement evidence you appear to be doing poorly enough to be summarily rejected.
    It's like Einstein said, space is conditioned by matter, altering its metrical qualities.
    He said it a lot more specifically than that. At this point, it appears that you have no real physics theory, just a claim about the speed of light. I will continue to use the one that I know has evidence and reject yours that apparently cannot describe a physical system, let alone match measurement evidence.
    No, I don't. All I need to do is point to what Einstein said and what Don Koks and Ned Wright and Irwin Shapiro said, and point out that there isn't any literal time flowing through a clock.
    When I look at those authors, I see a robust theory which uses time and can be supported by evidence. When I look at your theory, I see a gif and the stubborn refusal to look at a physical system in depth. This means that your theory cannot be considered to be anything like a serious rival to what you call "an ersatz version of GR." Even if you are correct about this, the "ersatz version" is clearly better than the one you offer because it can be used to do physics while your version cannot.
    I can't, nobody can. But I can point out that time isn't something that literally flows.
    Fair enough. I will continue to use physical theories that use time in very definite ways and that can be supported by evidence.
    No, you're the one who believes in fairies. You believe a clock measures the flow of time. It doesn't. That's just a figure of speech.
    All scientific theories are figures of speech. In this case, all you have is speech and your supposed opponent has a century of evidence you do not have, since you apparently cannot use your theory to measure anything.

    As I've said repeatedly, the mathematics is the same.
    You claim this, but the mathematics has a constant speed of light at every location, something you clearly deny. Not only that, it is clear that if we do a parallel transport of the speed of light from one location to another, the speed stays the same. This also seems to be something you deny. You need to either produce your own mathematics or explain this seeming contradiction.
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    In reply to Farsight, re: your posts in this thread.

    Would I be wrong in stating that "every aspect of the Universe is observer dependent?" This seems to be the "gist" of your writing...am I incorrect in this?

    (also, I liked the "to and fro" involved w/ #14 post...being told "you're wrong, because....because...well, you must be wrong because...well, you need math to support the math of the math" and

    so on and so forth. Written like a true politician! It's funny how things like "independent thought" are equated w/plague..."you must prove you aren't sick!")


    (Thanks for reading!)
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    Quote Originally Posted by Gerry Nightingale View Post
    (also, I liked the "to and fro" involved w/ #14 post...being told "you're wrong, because....because...well, you must be wrong because...well, you need math to support the math of the math" and

    so on and so forth. Written like a true politician! It's funny how things like "independent thought" are equated w/plague..."you must prove you aren't sick!")
    Gerry, we know that using GR, one can successfully send a rocket to another planet, a complicated and delicate procedure. The mathematics is important because it is how we measure how well a theory matches the real world. If someone wants to present a theory that they refuse to compare to the real world, that is fine. If they want to call such a theory physics, that isn't fine.
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    Quote Originally Posted by Farsight View Post
    {nonsensical parts excised}
    Everythng you have written is a combination of a diversion and irrelevance.

    You claim that two numbers, which are equal to each other, are different.

    Your claim is precisely that, and thus it really is that simple.

    Your introduction of gravitational time dilation is irrelevant. And, as with KJW, your explanation of it doesn't conform to mine. That is my polite way of saying that you're wrong. But none of that is relevant. What is relevant is the second sentence I wrote above.

    Your claim that two numbers are the same, yet different, makes no sense. That you claim that it does is a statement about your own internal logical problems, not one of physics. It is not possible to have a rational discussion with someone whose logical apparatus is fundamentally broken.

    Sorry.

    Those of us here whose logic is intact are thus limited to warning other readers to disregard virtually all of your assertions. The gap between their reliability and the passion with which they are presented is stark. The uninitiated might be fooled by your bluster, so it is incumbent upon us to sound the alarm.

    But keep on bleating, as you have for years.
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    In reply to #14, re: Critique? Rebuttal?

    Whatever. Say anything you wish to. (I would like to know how YOU are included in the assertions of the possessive "WE" w/ regard to physics theory, especially "Relativity". I was not aware

    you assisted Einstein in his work in this...I simply assumed he wrote it himself. My bad. Tell me though...which part of "GR" did you/we work on? The theory or the mathematical aspects?

    You should inform TFOLZO of this, as he is also something of an "A.E." biographer, and I think he is completely unaware you/we participated in "how GR works and what it means")


    (Thanks for reading!)
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    Quote Originally Posted by Gerry Nightingale View Post
    Would I be wrong in stating that "every aspect of the Universe is observer dependent?" This seems to be the "gist" of your writing...am I incorrect in this?
    Yes, you are incorrect. What happens in the universe, happens. How you see it depends on where you are and how you're moving. But whilst it might look different to you, it isn't different. For example two photons are created from electron-positron annihilation. Each has an E=hf energy of 511keV. If you rush towards one, it appears to be blue-shifted. But it hasn't gained any energy. It hasn't changed. Instead you changed.

    Quote Originally Posted by Gerry Nightingale View Post
    (also, I liked the "to and fro" involved w/ #14 post...being told "you're wrong, because....because...well, you must be wrong because...well, you need math to support the math of the math" and so on and so forth.
    There are some posters who will attempt to use sophistry to defend "the consensus view" against the evidence and what Einstein and others actually said. Sometimes it feels like they're self-appointed "custodians of ignorance" who pa-troll the internet attacking anybody who challenges orthodoxy. As if their reputations are threatened by scientific progress or something. I've had some problems with dark-matter people myself. I typically say when you understand relativity, you understand that dark matter doesn't consist of particles. Some guy who has spent twenty years down a mine trying to detect WIMPs isn't too keen on that, and will say anything to persuade people that I should not be listened to.


    Quote Originally Posted by PhysBang
    Gerry, we know that using GR, one can successfully send a rocket to another planet, a complicated and delicate procedure. The mathematics is important because it is how we measure how well a theory matches the real world. If someone wants to present a theory that they refuse to compare to the real world, that is fine. If they want to call such a theory physics, that isn't fine.
    Only I'm not presenting a theory. I'm telling you a truth, one which is supported by Einstein and the evidence. And by Koks and Magueijo and Moffat and Wight. And by Victor Stenger who says this in his Huffington Post blog:

    "Light does not always travel at the speed c. It generally moves slower than c in a medium. And, as Einstein showed, light also slows down in passing by the sun or through any other strong gravitational field. "
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    Quote Originally Posted by PhysBang View Post
    Sure, but you can't ignore the content of what they are referring to. You claim to have read Ellis, but you then dismiss everything that he writes without comment or reason.
    They described a tautology. That's it.

    Quote Originally Posted by PhysBang View Post
    You actually say that the speed of light varies with position which causes curvature, but without any details. This is a reverse of what Einstein actually says (sufficient vs necessary conditions) and you seem to violate the details that Einstein wrote into the mathematics. This is why you should produce the details that you have, so far, not provided.
    I haven't given the reverse of what Einstein actually says. Einstein said a curvature of rays of light can only occur when the speed of light varies with position. The word velocity appears in the English translation but as Don Koks said, Einstein meant speed. This is obvious because he was referring to the SR postulate.

    Quote Originally Posted by PhysBang View Post
    Again you dismiss the entire content of Ellis' paper and the subsequent expansion upon it that Magueijo and Moffat do. Again without apparent justification.
    It just isn't relevant. What is, is the tautology described by Magueijo and Moffat.

    Quote Originally Posted by PhysBang View Post
    If you believe so, then the onus is on you to show the true details. These details are apparently ones that Einstein never wrote down mathematically, so you will have to provide these mathematical details.
    As I've said repeatedly, there aren't any. I cannot use mathematics to prove that there is no literal time flowing through a clock.

    Quote Originally Posted by PhysBang View Post
    But you disagree with both the conditional nature of his statement and his mathematical details, therefore you are presenting what appears to be a special theory that is wholly your own. If you can produce the mathematical details, then we can see if there is a difference.
    I'm not. I'm not some my-theory guy.

    Quote Originally Posted by PhysBang View Post
    Contemporary physicists have a very specific means of discussing these types of phenomena that goes well beyond this and matches the available evidence. If you have nothing better, then I'm afraid that on the measurement evidence you appear to be doing poorly enough to be summarily rejected.
    You can reject it if you wish, but others aren't rejecting it. What I'm saying is gaining ground.

    Quote Originally Posted by PhysBang View Post
    He said it a lot more specifically than that. At this point, it appears that you have no real physics theory, just a claim about the speed of light.
    Correct. A claim that is backed up by the evidence and other authors including Einstein.

    Quote Originally Posted by PhysBang View Post
    I will continue to use the one that I know has evidence and reject yours that apparently cannot describe a physical system, let alone match measurement evidence.
    My claim is supported by the evidence. Your conviction isn't.

    Quote Originally Posted by PhysBang View Post
    When I look at those authors, I see a robust theory which uses time and can be supported by evidence. When I look at your theory, I see a gif and the stubborn refusal to look at a physical system in depth. This means that your theory cannot be considered to be anything like a serious rival to what you call "an ersatz version of GR." Even if you are correct about this, the "ersatz version" is clearly better than the one you offer because it can be used to do physics while your version cannot...
    You're saying nothing. You have no counterargument, all you have is rejection, and you're clutching at straws to reject what I'm telling you and dismiss not just me, but Einstein too.

    Quote Originally Posted by PhysBang View Post
    You claim this, but the mathematics has a constant speed of light at every location, something you clearly deny. Not only that, it is clear that if we do a parallel transport of the speed of light from one location to another, the speed stays the same. This also seems to be something you deny. You need to either produce your own mathematics or explain this seeming contradiction.
    If the speed of light was really the same, those two NIST optical clocks would stay synchronised, and they don't. Your understanding of the mathematics is wrong, in that you imagine the speed of light is constant whilst "the flow of time" varies. But there is no flow of time. There is no time flowing through a clock. A clock "clocks up" some kind of regular cyclical motion and shows you a cumulative display that you call "the time". So when the clock goes slower the motion goes slower. This is true of mechanical clocks, quartz wristwatches, and optical clocks. Get used to it. Because it is coming soon to an institution near you.
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    Quote Originally Posted by tk421 View Post
    Quote Originally Posted by Farsight
    {nonsensical parts excised}
    Everythng you have written is a combination of a diversion and irrelevance.

    You claim that two numbers, which are equal to each other, are different.

    Your claim is precisely that, and thus it really is that simple.

    Your introduction of gravitational time dilation is irrelevant. And, as with KJW, your explanation of it doesn't conform to mine. That is my polite way of saying that you're wrong. But none of that is relevant. What is relevant is the second sentence I wrote above.

    Your claim that two numbers are the same, yet different, makes no sense. That you claim that it does is a statement about your own internal logical problems, not one of physics. It is not possible to have a rational discussion with someone whose logical apparatus is fundamentally broken.

    Sorry.

    Those of us here whose logic is intact are thus limited to warning other readers to disregard virtually all of your assertions. The gap between their reliability and the passion with which they are presented is stark. The uninitiated might be fooled by your bluster, so it is incumbent upon us to sound the alarm.

    But keep on bleating, as you have for years.
    I'm saying two speeds aren't the same, as demonstrated by the NIST optical clocks which we idealise to parallel-mirror light clocks:



    You're saying nothing, you're just abusive and dismissive.
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    Quote Originally Posted by Farsight View Post
    I'm saying two speeds aren't the same, as demonstrated by the NIST optical clocks which we idealise to parallel-mirror light clocks:
    You cannot simultaneously claim that the speeds are the same and also different. The animation you keep repeating ad nauseam doesn't apply to your claim, so please desist.

    You're saying nothing, you're just abusive and dismissive.
    I'm saying that you are wrong. That is dismissive, and also correct.
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    Quote Originally Posted by tk421 View Post
    You cannot simultaneously claim that the speeds are the same and also different.
    No, I'm saying the two speeds aren't the same. Look at the thread title. They're different because the seconds aren't the same. Because of gravitational time dilation. You said two numbers are the same. Sure they are. 100mph is the same number as 100m/s, but the two speeds aren't the same.

    Quote Originally Posted by tk421 View Post
    The animation you keep repeating ad nauseam doesn't apply to your claim, so please desist.
    The animation does apply. it's an idealised version of the NIST optical clocks.

    Quote Originally Posted by tk421 View Post
    I'm saying that you are wrong. That is dismissive, and also correct.
    No, I'm not wrong. Einstein and the evidence is with me, and so is Shapiro, Wright, Koks, Magueijo and Moffat, and Stenger.
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    Quote Originally Posted by Farsight View Post
    No, I'm saying the two speeds aren't the same. Look at the thread title.
    The thread title is "How can 299792458 m/s be different to 299792458 m/s"

    The speeds are the same. The units are the same. There is absolutely nothing that is not the same about them.

    Quote Originally Posted by Farsight View Post
    They're different because the seconds aren't the same. Because of gravitational time dilation.
    Of course the seconds are the same, and no experiment anyone can perform can find a difference between them. Any form of clock you care to mention will show the same form of seconds down here as it does up there. Any physical process that has a duration of a certain amount of seconds will have the same duration when measured in its rest frame whether it is measured at a lower or a higher gravitational potential. A second is always a second. In terms of PROPER time, that is.

    The COORDINATE speed of light can, of course, differ from the proper speed, as occurs close to a gravitational source, and is most obvious close to a black hole. But anyone in that region making the measurement will find the proper speed of light to be the same as always, because a second is always a second in proper terms.

    The COORDINATE speed of light can differ by position, but the proper speed is always 299792458 m/s.

    Quote Originally Posted by Farsight View Post
    You said two numbers are the same. Sure they are. 100mph is the same number as 100m/s, but the two speeds aren't the same.
    That's using different units. ""How can 299792458 m/s be different to 299792458 m/s" uses the same units.

    Quote Originally Posted by Farsight View Post
    No, I'm not wrong. Einstein and the evidence is with me, and so is Shapiro, Wright, Koks, Magueijo and Moffat, and Stenger.
    According to you, and you alone. Which is why your posts on these subjects are limited to this particular section of the forum.
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    Farsight, everything moves through space-time at the speed c. Relative motion only affects the angles between the second in one frame and that in another, so the second in one frame when projected onto the other frame can be different. (My time can be your space so to speak). However locally they still the same.

    I think we are back to the semantics again. Locally the second is the second. Only when transforming from one frame to another are they going to be different.
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    Quote Originally Posted by SpeedFreek View Post
    The thread title is "How can 299792458 m/s be different to 299792458 m/s"

    The speeds are the same. The units are the same. There is absolutely nothing that is not the same about them.
    Not so. Gravitational time dilation means the second at the lower location is bigger than the second at the higher location. So whilst both speeds are 299792458m/s they aren't the same.

    Quote Originally Posted by SpeedFreek View Post
    Of course the seconds are the same, and no experiment anyone can perform can find a difference between them. Any form of clock you care to mention will show the same form of seconds down here as it does up there.
    And for any form of clock you care to mention* the lower clock goes slower than the upper clock. Lots have experiments have detected this difference.

    Quote Originally Posted by SpeedFreek View Post
    Any physical process that has a duration of a certain amount of seconds will have the same duration when measured in its rest frame whether it is measured at a lower or a higher gravitational potential.
    And you can set up an experiment where the same physical process is occurring at two different elevations. The upper process is finished before the lower process. The durations aren't the same.

    Quote Originally Posted by SpeedFreek View Post
    A second is always a second. In terms of PROPER time, that is.
    You haven't understood the tautology. The second is defined using an electromagnetic process. As is the metre. Then the second and the metre are used to measure the speed of an electromagnetic process.

    Quote Originally Posted by SpeedFreek View Post
    The COORDINATE speed of light can, of course, differ from the proper speed, as occurs close to a gravitational source, and is most obvious close to a black hole. But anyone in that region making the measurement will find the proper speed of light to be the same as always, because a second is always a second in proper terms.
    We define the second to be the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. It's like you sit there counting 9192631770 microwaves coming past you, then you jump up and say "that's a second". When the microwaves are coming past you slower the second is bigger.


    Quote Originally Posted by SpeedFreek View Post
    The COORDINATE speed of light can differ by position, but the proper speed is always 299792458 m/s.
    No, the speed of light can differ by position. That's what Einstein said.

    Quote Originally Posted by SpeedFreek View Post
    That's using different units. ""How can 299792458 m/s be different to 299792458 m/s" uses the same units.
    They aren't the same because the seconds are the same.

    Quote Originally Posted by SpeedFreek View Post
    According to you, and you alone. Which is why your posts on these subjects are limited to this particular section of the forum.
    No, it isn't me alone. It's Einstein too. And Irwin Shapiro. And Ned Wright. And Don Koks. And Victor Stenger. And Magueijo and Moffat and more. I'm limited to this section of the forum unfairly.


    * apart from a grandfather clock, where the rate clocks rate depends on the force of gravity rather than gravitational potential.
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    Quote Originally Posted by Jilan
    I think we are back to the semantics again
    No, this is not a semantic problem. The definitions of concepts are the same for every one here, but Farsight. He has a cognitive dissonance based on his idea about time flowing differently, and his other idea that time does not flow.

    The problem is simply with logic. The the meter is the same, the second is the same. So the only plausible solution is that both number are expressed in a different base (let's say 10 vs 42).

    It is a very simple question with very simple answer. The dissonance always boils down to "be different", where how exactly the comparison is to be done is left un-answered.

    At the top of this page there is a question with identical pixels representing identical speed.

    And there is an animated .gif with time ticking differently but in the same FoR. Something yet to be observed.
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    Quote Originally Posted by Jilan View Post
    Farsight, everything moves through space-time at the speed c.
    It doesn't. Nothing moves through spacetime at all. It's static. It's the "block universe" where time is a fourth dimension, and all times are presented at once. We draw a world line in spacetime to model motion through space over time, but there's no motion in spacetime whatsoever. See this post where Markus said this: "The concept of space-time does away with "motion" in the classical sense, and replaces it with static world lines; the equations of motion then become the geodesic equations".

    Quote Originally Posted by Jilan View Post
    Relative motion only affects the angles between the second in one frame and that in another, so the second in one frame when projected onto the other frame can be different. (My time can be your space so to speak). However locally they're still the same.
    The NIST optical clocks lose synchronisation when one is a mere 30cm above the other. That's pretty local. So locally they aren't the same. If you ask around about this somebody will tell you that a local region means an infinitesimal region. But that's a region of no extent. So it's no region. On that basis there is no local. On that basis you can't even talk sensibly about the local speed of light, because it's given as metres per second, and one metre is more than the 30cm that PhysBang says isn't local. Hold your hand up a foot in front of your face. PhysBang will tell you that that isn't local.

    Quote Originally Posted by Jilan
    I think we are back to the semantics again. Locally the second is the second. Only when transforming from one frame to another are they going to be different.
    Remember that a frame is an abstract thing. Two optical clocks in a room isn't. The lower clock goes slower than the other. And there isn't any time flowing through those clocks, just light, moving. Yes, we're back to semantics, and semantics means meaning. It's important. And the meaning is this: when an optical clock goes slower when it's lower, it's because light goes slower when it's lower. Not for any other reason.
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    Farsight has yet to deliver on something important: how to calculate the speed of light as a function of space-time position. He ought to be able to derive it from the equations of general relativity. Scriptural exegesis won't do, and that's quoting Einstein or whomever, interpreting those quotes, and then insinuating that anyone who does not agree with those interpretations rejects Einstein or whomever.

    The speed of light here is the null-geodesic speed. It is thus fixed by the geometry of space-time.

    As to measurements of it being affected by curvature, I recently considered the issue, and here is what I found. Imagine that you wanted to find the null-geodesic speed from point A to point B. You shoot a spacelike geodesic from A to a third point X, and a timelike one from X to B, with AX and XB perpendicular. That's an extension of what one would do in flat space-time. I've calculated the size of the variation in this calculated speed for nearly-flat space-time, with
    AX = s1
    XB = s2

    for length / time s

    It is


    So its value changes as one moves X except for some special cases like maximal symmetry. This is contrary to what Farsight seems to believe, that it is some well-defined value.
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    Quote Originally Posted by Boing3000 View Post
    No, this is not a semantic problem. The definitions of concepts are the same for every one here, but Farsight. He has a cognitive dissonance based on his idea about time flowing differently, and his other idea that time does not flow.
    No I don't have a cognitive dissonance, you do. You are clinging to conviction and to ignorance. Einstein and the evidence and all those other guys are on my side.

    Quote Originally Posted by Boing3000 View Post
    The problem is simply with logic. The meter is the same, the second is the same. So the only plausible solution is that both number are expressed in a different base (let's say 10 vs 42).
    Wrong! The seconds aren't the same. If they were there wouldn't be any such thing as gravitational time dilation.

    Quote Originally Posted by Boing3000 View Post
    It is a very simple question with very simple answer. The dissonance always boils down to "be different", where how exactly the comparison is to be done is left un-answered. At the top of this page there is a question with identical pixels representing identical speed. And there is an animated .gif with time ticking differently but in the same FoR. Something yet to be observed.
    It is observed. NIST have done experiments with super-accurate optical clocks where one is only 30cm above the other. The lower clock is seen to go demonstrably slower. Go and read the David Wineland interview:

    "But there are some more interesting ones. For example, gravity affects the rate that clocks run. One of the effects of gravity comes from Einstein's theory of general relativity. And one of the consequences of Einstein's theory of general relativity was that clocks, if they're placed near a gravitational mass, say the Earthwill run at a slower rate than if they're removed from the sourcesay clocks on a satellite. But nowadays the precision of the clocks is such that we have to worry, when we compare clocks, if one clock in one lab is 30 centimeters higher than the clock in the other lab, we can see the difference in the rates they run at. And this is an extremely small effect that we haven't had to worry about before."
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    Quote Originally Posted by Farsight View Post
    It doesn't. Nothing moves through spacetime at all. It's static. It's the "block universe" where time is a fourth dimension, and all times are presented at once.
    This is imagining that we are looking from outside. But we are inside of it, and that makes us perceive change over time.

    The NIST optical clocks lose synchronisation when one is a mere 30cm above the other. That's pretty local.
    In an everyday sense, maybe, but not in a theoretical sense. Farsight, you ought to present your ideas at a theoretical-physics journal club and see what response you get.
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    Quote Originally Posted by Farsight View Post
    They described a tautology. That's it.
    So you are going to take one quotation out of an entire paper, ignore the rest of the paper and the specific citation that they make in the quotation because the details might not coincide with your claims. This is what we call cherry-picking; it is a fallacious form of argument. At the very least, you have to distinguish between your variable speed of light theory and what those authors describe as a variable speed of light theory.
    I haven't given the reverse of what Einstein actually says. Einstein said a curvature of rays of light can only occur when the speed of light varies with position. The word velocity appears in the English translation but as Don Koks said, Einstein meant speed. This is obvious because he was referring to the SR postulate.
    If this is the case, it should be easy for you to demonstrate the varying of the speed of light by position that Einstein used.
    It just isn't relevant. What is, is the tautology described by Magueijo and Moffat.
    Surely those authors believe that the remainder of their paper on this very topic is relevant. If you cite their paper where they go into great detail on this topic, then you should at least say why everything else in their paper is incorrect. It does a disservice to your reader to make it look like the paper is something that is an authority on the subject when in fact you believe that the authors are very wrong on this very subject. This undermines your argument, since it now seems to be a fluke that the authors made that point at all and that, in general, you think that the work of the authors is work rejecting.
    As I've said repeatedly, there aren't any. I cannot use mathematics to prove that there is no literal time flowing through a clock.
    You are avoiding the real question. I was asking there about the "ersatz version of GR" that you describe. If such a thing exists, you need to demonstrate what it is, what the real version is, and what the difference between them is. It would be nice, ideally, if you could show us where in Einstein's work (not his commentary) the difference lies. This involves showing us the mathematics of the physics, since that is how the work of physics gets done. In order to do his physics, Einstein developed a new field of mathematics. He did this because it was necessary to produce a meaningful physics. If we ignore that, then we ignore his work and insult his memory.
    I'm not. I'm not some my-theory guy.
    You are offering us a claim that there exists an "ersatz version of GR" and a supposedly true version of GR. That is your theory. So far, you have done nothing to defend this theory as you have not addressed the content of GR in a serious way.
    You can reject it if you wish, but others aren't rejecting it. What I'm saying is gaining ground.
    That is a shame, since you seem to be offering us a return to pre-Enlightenment lives where science uses the principles of alchemy and does not use mathematics. I respect the correct reasoning in the correct disciplines, in this case, I cannot accept your textual analysis in the place of real physics.
    [PhysBang: " At this point, it appears that you have no real physics theory, just a claim about the speed of light."] Correct. A claim that is backed up by the evidence and other authors including Einstein.
    Well, I suppose it is a step forward for you to admit that you are not making physics claims.
    My claim is supported by the evidence. Your conviction isn't.
    It is interesting that you use the word "evidence" and not the phrase "measurement evidence". I suppose that this is a sign that you are embracing that you are not doing physics and that you are simply doing a (limited) textual analysis. My conviction that Einstein's work was more complicated than you present is based on the textual analysis of seeing that there is a great deal of mathematics there on this subject that you do not address.
    You're saying nothing. You have no counterargument, all you have is rejection, and you're clutching at straws to reject what I'm telling you and dismiss not just me, but Einstein too.
    That doesn't seem true. As I have said, with the "ersatz version of GR" that you say is incorrect, people can build working machines and can successfully compute and use complicated trajectories. You, on the other hand, offer us what you admit is not a physics claim but merely a claim about the speed of light. That claim cannot be used in any meaningful way.

    It is actually funny that the only case that you predict in one with NIST optical clocks 30cm apart from each other. And even in that case you give a vague prediction. If we were to compare your statement to the rich theory of the "ersatz version of GR", then the evidence in physics clearly lies with the "ersatz version of GR".

    It is funny that you want to lead people away from the practicality of mathematical physics that built things like optical clocks towards the kind of ineffectual textual-analysis in a theological vein that seemed to dominate the Dark Ages.
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    Quote Originally Posted by Farsight View Post
    Not so. Gravitational time dilation means the second at the lower location is bigger than the second at the higher location.
    Can you show this with an example with some numbers and the relevant physics? Or at least give us some textual analysis? It seems counter-intuitive to say that a change in timing produces a change in size.
    And for any form of clock you care to mention* the lower clock goes slower than the upper clock. Lots have experiments have detected this difference.
    Since every clock changes speed, and indeed every single physical system as Einstein said (at one point he actually recommended that people not think about clocks at all), this is why people say that time changes, not merely the appearance of time. To say otherwise is to claim that there is a single standard for time, an absolute reference frame, which is a hidden part of the theory.
    * apart from a grandfather clock, where the rate clocks rate depends on the force of gravity rather than gravitational potential.
    Can you show us an example so that we can understand just how significant this factor is? Or can you at lest provide us with some textual analysis?
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    Quote Originally Posted by lpetrich View Post
    Farsight has yet to deliver on something important: how to calculate the speed of light as a function of space-time position. He ought to be able to derive it from the equations of general relativity.
    It's done already and you know it, only it's called the coordinate speed of light. Note that the elapsed time t displayed by an optical clock at some elevation is directly dependent on the coordinate speed of light at that elevation, because the optical clock is effectively counting some regular cyclical electromagnetic motion. Hence the well-know expression below gives the ratio between the speed of light at two elevations:



    Quote Originally Posted by lpetrich View Post
    Scriptural exegesis won't do, and that's quoting Einstein or whomever...
    What won't do is dismissing what Einstein Koks Wright Shapiro Magueijo Moffat and Stenger said as "scriptural exegesis".

    Quote Originally Posted by lpetrich View Post
    The speed of light here is the null-geodesic speed. It is thus fixed by the geometry of space-time.
    You've got that back to front. The speed of light, in space made inhomogeneous by a concentration of energy, determines the geometry of the abstract mathematical model called spacetime.

    Quote Originally Posted by lpetrich View Post
    As to measurements of it being affected by curvature...
    Again that's back to front. It's a curvature in your metric. A curvature in your plot of measurements. It's like what I said in the gravity thread. The clocks nearer the Earth dont run slower because your plot is of clock rates is curved. They run slower because light goes slower, because space is different. Because the speed of light varies with position.

    Quote Originally Posted by lpetrich
    This is imagining that we are looking from outside. But we are inside of it, and that makes us perceive change over time.
    No, we aren't inside of it. Spacetime is just a mathematical model. It's the map, and the map is not the territory. We're in space, things move, things change, shit happens. We don't just perceive change, change happens. It's real. But what we don't perceive are world lines and light cones. Like spacetime, they are abstract things that don't actually exist. Nor does "the flow of time" actually exist. It's just a figure of speech.

    Quote Originally Posted by lpetrich
    Quote Originally Posted by Farsight
    The NIST optical clocks lose synchronisation when one is a mere 30cm above the other. That's pretty local.
    In an everyday sense, maybe, but not in a theoretical sense. Farsight, you ought to present your ideas at a theoretical-physics journal club and see what response you get.
    It's local in a theoretical sense. More local than the metre in 299792458 m/s. And these aren't my ideas, these are Einstein's ideas.
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    All: apologies, the thread title said m/s rather than m/s. I've changed it.
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    Quote Originally Posted by Farsight View Post
    What won't do is dismissing what Einstein Koks Wright Shapiro Magueijo Moffat and Stenger said as "scriptural exegesis".
    In this context, it seems acceptable, though not entirely exact. Remember, Farsight, you reject everything that Magueijo and Moffat write in their paper except the very limited quotation that you like. In reality, you are the only one here rejecting what they write.

    You've got that back to front. The speed of light, in space made inhomogeneous by a concentration of energy, determines the geometry of the abstract mathematical model called spacetime.
    This seems to be exactly the opposite conditional from the one you quote from Einstein. Producing the mathematics of what you identify as the real GR as opposed to contemporary versions could help identify the difference. But as you have admitted that you have no physics, we probably should examine your position as something akin to performance art or poetry, not physics.
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    Quote Originally Posted by PhysBang View Post
    In this context, it seems acceptable, though not entirely exact. Remember, Farsight, you reject everything that Magueijo and Moffat write in their paper except the very limited quotation that you like. In reality, you are the only one here rejecting what they write.
    It isn't acceptable, it's dismissal. And I don't reject everything that Magueijo and Moffat write in their paper. I merely referred to the tautology that they pointed out, wherein the local motion of light is used to define the metre and the second, which are then used to measure the local motion of light. It's a patent tautology.

    Quote Originally Posted by PhysBang View Post
    This seems to be exactly the opposite conditional from the one you quote from Einstein. Producing the mathematics of what you identify as the real GR as opposed to contemporary versions could help identify the difference. But as you have admitted that you have no physics, we probably should examine your position as something akin to performance art or poetry, not physics.
    It isn't opposite, I've said repeatedly that it's the same mathematics, and I have not admitted that I have no physics. So it's quite clear that you do not wish to discuss this matter sincerely.
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    Quote Originally Posted by Farsight View Post
    It isn't acceptable, it's dismissal. And I don't reject everything that Magueijo and Moffat write in their paper. I merely referred to the tautology that they pointed out, wherein the local motion of light is used to define the metre and the second, which are then used to measure the local motion of light. It's a patent tautology.
    You clearly reject everything else that they wrote, since you refuse to address what they and Ellis say about Lorentz symmetry. You may have rejected their work so thoroughly that you don't even realize that they discuss it. You certainly ignore their work as much as you ignored my previous posts.

    It isn't opposite, I've said repeatedly that it's the same mathematics, and I have not admitted that I have no physics.
    When I wrote, "At this point, it appears that you have no real physics theory, just a claim about the speed of light," You replied, "Correct." If you did not mean that you are not presenting a real physics theory, then you should probably explain yourself. And you should probably present some real physics.

    As to the mathematics: since you say contradictory things, it would be best for you to walk us through your examples with mathematics and specifically chosen values for initial conditions.
    So it's quite clear that you do not wish to discuss this matter sincerely.
    I have repeatedly asked you for the specific details of your claims. You have repeatedly dodged the questions. For over a decade, you have not answered specific questions while claiming to have answers.
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    Quote Originally Posted by Farsight View Post
    All: apologies, the thread title said m/s rather than m/s. I've changed it.
    The title error is the least of your errors, Duffield.

    Like this hilarious sample of your "science":

    Quote Originally Posted by Farsight
    But the two speeds are not the same because the seconds aren't the same.
    Actually, seconds, as units of measurement, do not change. Physics is tough when you are just a poser.
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    Quote Originally Posted by x0x View Post
    Physics is tough when you are just a poser.
    This is an inappropriate comment, x0x, an ad hominem. Attack the argument, not the person making it. Consider this a final warning or be prepared to take some time off.
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    Quote Originally Posted by Faright
    Wrong! The seconds aren't the same. If they were there wouldn't be any such thing as gravitational time dilation.
    That demonstrate that you are the one clinging to conviction and ignorance. Above that, it contradicts what Einstein and all physicists have concluded, as well as experimentally measured. Your are again showing sign of cognitive dissonance, because you also pretend you agree with them.

    BTW thoses seconds are not the same, because they are 30 centimeter a part in a gravitational field. Do you agree or not ?
    And if you have a light mirror beside those two NIST clocks, both lights would be at exactly at the same place, that is the number of elapse second multiplied by 299792458 m. Because light speed is a constant, as observed by experimental evidence.

    You should also get acquainted with the technology of atomic clock. The tick counting is not based on electromagnetic phenomenon, so there is no tautology here.

    Quote Originally Posted by Farsight
    speed of light, in space made inhomogeneous by a concentration of energy, determines the geometry of the abstract mathematical model called spacetime.
    Another of your cognitive dissonance. I don't know how an "abstract mathematical model" is influencing light speed (you neither, you've still not provided your other abstract mathematics). More importantly, you cannot justify how energy influence this "abstract model".

    You should choose if you think those things are real or not not. Then maybe you'll be able to see the light.
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    Quote Originally Posted by Farsight View Post
    We define the second to be the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. It's like you sit there counting 9192631770 microwaves coming past you, then you jump up and say "that's a second". When the microwaves are coming past you slower the second is bigger.
    No. The microwaves aren't coming past you slower and the second isn't bigger. The microwaves are coming past you at the same speed, regardless of your gravitational potential. The fact that someone at a different gravitational potential will measure the microwaves to be coming past you slower when using their clock does not mean that the microwaves are actually coming past you any slower than the speed that they pass the other observer.

    Why are you rejecting both postulates of Special Relativity, whilst at the same time claiming the correct interpretation of Einstein's theory?
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    Thanks SpeedFreak.

    Quote Originally Posted by Boing3000 View Post
    That demonstrate that you are the one clinging to conviction and ignorance. Above that, it contradicts what Einstein and all physicists have concluded, as well as experimentally measured. Your are again showing sign of cognitive dissonance, because you also pretend you agree with them.
    Huh? Einstein said light curves because the speed of light varies with position. I agree with that. Shapiro said the speed of propagation of a light ray decreases as it passes through a region of decreasing gravitational potential. I agree with that/

    Quote Originally Posted by Boing3000 View Post
    BTW thoses seconds are not the same, because they are 30 centimeter a part in a gravitational field. Do you agree or not ?
    Yes. The second varies with gravitational potential, with elevation, we call it gravitational time dilation.

    Quote Originally Posted by Boing3000 View Post
    And if you have a light mirror beside those two NIST clocks, both lights would be at exactly at the same place, that is the number of elapse second multiplied by 299792458 m. Because light speed is a constant, as observed by experimental evidence.
    It isn't observed to be constant. The experimental evidence is that the speed of light decreases in line with gravitational potential. If you put a parallel-mirror light clock right next to each NIST optical clock, each parallel-mirror will stay synchronised with its NIST optical clock. But the lower NIST clock goes slower than the upper NIST clock, and the lower parallel-mirror light clock goes slower than the upper parallel-mirror light clock.

    Quote Originally Posted by Boing3000 View Post
    You should also get acquainted with the technology of atomic clock. The tick counting is not based on electromagnetic phenomenon, so there is no tautology here.
    Yes it is. The hyperfine spin flip and the associated microwaves are electromagnetic. See this NIST article on the F1 Cesium Fountain Atomic Clock.

    Quote Originally Posted by Boing3000 View Post
    Another of your cognitive dissonance. I don't know how an "abstract mathematical model" is influencing light speed (you neither, you've still not provided your other abstract mathematics). More importantly, you cannot justify how energy influence this "abstract model". You should choose if you think those things are real or not not. Then maybe you'll be able to see the light.
    ??? A concentration of energy conditions the surrounding space. That's what Einstein said. It alters it, the effect diminishing with distance.
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    Quote Originally Posted by SpeedFreek View Post
    No. The microwaves aren't coming past you slower and the second isn't bigger. The microwaves are coming past you at the same speed, regardless of your gravitational potential.
    No they aren't. If they were, the second would be the same. The coordinate speed of light wouldn't vary with gravitational potential.

    Quote Originally Posted by SpeedFreek View Post
    The fact that someone at a different gravitational potential will measure the microwaves to be coming past you slower when using their clock does not mean that the microwaves are actually coming past you any slower than the speed that they pass the other observer.
    Yes it does mean that. The second is the duration of 9192631770 microwaves coming past you. If those microwaves were coming past you at the same speed regardless of your altitude, there wouldn't be any gravitational time dilation. Understand the tautology. You define your second using light moving, then use it to measure light moving. Then you say light always moves at the same speed. When it doesn't.

    Quote Originally Posted by SpeedFreek View Post
    Why are you rejecting both postulates of Special Relativity, whilst at the same time claiming the correct interpretation of Einstein's theory?
    I'm only rejecting one, because Einstein rejected it. Here's the quotes:

    1911: "If we call the velocity of light at the origin of coordinates c₀, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = c₀(1 + Φ/c).

    1912: "On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential".

    1913: "I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis".

    1915: "the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned".

    1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position.


    The word velocity appears in the English translations, but what Einstein actually said in 1916 was "die Ausbreitungsgeschwindigkeit des Lichtes mit dem Orte variiert". That translates to "the propagation speed of the light with the place varies". And note that he said "which constitutes one of the two fundamental assumptions in the special theory of relativity". He's saying the SR postulate doesn't apply for GR. It is to be abandoned. Hence Don Koks said this in the Baez article:

    "Einstein talked about the speed of light changing in his new theory. In his 1920 book "Relativity: the special and general theory" he wrote: "... according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [...] cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity [Einstein means speed here] of propagation of light varies with position." This difference in speeds is precisely that referred to above by ceiling and floor observers."

    I'm right, SpeedFreak. And all those people who told you the speed of light is absolutely constant, are wrong.
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    Quote Originally Posted by Farsight View Post
    It isn't observed to be constant.
    Yes it is.

    Quote Originally Posted by Farsight View Post
    The experimental evidence is that the speed of light decreases in line with gravitational potential.
    That's the COORDINATE speed, not the PROPER speed.

    The lower the gravitational potential, the greater the gravitational time-dilation. An observer at a low gravitational potential (i.e. near a gravitational source) will measure the speed of light, locally, to be 299792458 m/s. An observer at a higher gravitational potential (i.e. at a greater distance from the gravitational source) will also measure the speed of light, locally, to be 299792458 m/s.

    The observer at the lower gravitational potential will calculate that a clock at a higher gravitational potential is "ticking faster" than their own, and vice versa.

    Quote Originally Posted by Farsight View Post
    If you put a parallel-mirror light clock right next to each NIST optical clock, each parallel-mirror will stay synchronised with its NIST optical clock. But the lower NIST clock goes slower than the upper NIST clock, and the lower parallel-mirror light clock goes slower than the upper parallel-mirror light clock.
    Of course, from the frame of the lower clock, the upper clock goes faster.

    Now let's look at this in different terms - constant acceleration (remember the equivalence principle here). We can use Rinder coordinates for this, and what do we find? We find that, at a certain distance from the constantly accelerating frame, the COORDINATE speed of light is ZERO. This is known as the "Rindler Horizon".

    It is purely a coordinate effect. If we had another observer in an inertial frame of reference sitting at the same coordinates as the accelerating observer calculates the Rindler horizon to be, they certainly would NOT measure the speed of light to be ZERO, would they?
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    Quote Originally Posted by Farsight View Post
    I'm right, SpeedFreak. And all those people who told you the speed of light is absolutely constant, are wrong.
    What you are referring to is the coordinate speed of light, which can indeed vary. We know this. But nobody ever measures the proper speed of light to vary.

    The speed of light varies with position FROM THE OBSERVER. Locally to the observer, it never varies.

    We can take this even further if we invoke cosmological models like the current consensus model - LCDM concordance. Here, the proper speed of light is always c, but the coordinate speed of light on our past light cone was NEGATIVE for the first 4.5 billion years of the history of our universe. This is no great insight. Nor does it have any bearing on how time actually passed during the history of our universe.
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    I have heard that "tautology" argument before. Some misguided people seem to think that, because technological developments in our apparatus allowed measurements so accurate that we came to a point where we defined the length of a metre in terms of the speed of light, the laws of physics suddenly changed. They didn't.
    Last edited by SpeedFreek; 09-07-2014 at 12:52 AM.
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    Quote Originally Posted by Farsight
    Huh? Einstein said light curves because the speed of light varies with position. I agree with that.
    No he did not. So you agree with something he did not say. In fact he said the contrary. So you are contradicting Einstein theory, and factual experiment.

    Shapiro said the speed of propagation of a light ray decreases as it passes through a region of decreasing gravitational potential. I agree with that
    And back to cognitive dissonance. Because every body agrees with that. But you don't agree we agree, because you don't understand the concept of proper speed vs coordinate speed.
    Maybe it is time to change the thread title again.

    It isn't observed to be constant. The experimental evidence is that the speed of light decreases in line with gravitational potential
    You've still to point that conter experiment, who have done it, how, who have reproduce it.
    Because it is factually the opposite that happens.

    Yes it is. The hyperfine spin flip and the associated microwaves are electromagnetic
    No it is not. Hyperfine spin flip, concerns some oscillating behaviors of the electron.
    The fact that the probing is done with electromagnetic wave is irrelevant. Likewise the fact the you can probe your good old grand-father clock with your ears does not make it a sound clock.

    ??? A concentration of energy conditions the surrounding space. That's what Einstein said. It alters it, the effect diminishing with distance.
    That is incorrect He said a concentration of energy conditions the surrounding space-time. That's what Einstein said.
    Beside he consider space-time to be real, not abstract.

    If you wan't to continue to contradict Einstein, you should be able to come up with a minimal set of hypothesis and mathematics.

    But first you should start by explaining how 1 unit could be different to 1 unit.
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    Quote Originally Posted by Farsight View Post
    Huh? Einstein said light curves because the speed of light varies with position.
    No, as you often quote, Einstein said, "a curvature of rays of light can only occur when the speed of light varies with position". This does not imply cause. If you think that there is a cause, then show us the mathematics and show us where Einstein includes the cause in his mathematics.

    If you want to do physics, then do physics. So far, you have done nothing that should allow anyone to take you seriously.

    Since you like avoiding questions, let me repeat my comments from above.
    Quote Originally Posted by Farsight View Post
    They described a tautology. That's it.
    So you are going to take one quotation out of an entire paper, ignore the rest of the paper and the specific citation that they make in the quotation because the details might not coincide with your claims. This is what we call cherry-picking; it is a fallacious form of argument. At the very least, you have to distinguish between your variable speed of light theory and what those authors describe as a variable speed of light theory.
    I haven't given the reverse of what Einstein actually says. Einstein said a curvature of rays of light can only occur when the speed of light varies with position. The word velocity appears in the English translation but as Don Koks said, Einstein meant speed. This is obvious because he was referring to the SR postulate.
    If this is the case, it should be easy for you to demonstrate the varying of the speed of light by position that Einstein used.
    It just isn't relevant. What is, is the tautology described by Magueijo and Moffat.
    Surely those authors believe that the remainder of their paper on this very topic is relevant. If you cite their paper where they go into great detail on this topic, then you should at least say why everything else in their paper is incorrect. It does a disservice to your reader to make it look like the paper is something that is an authority on the subject when in fact you believe that the authors are very wrong on this very subject. This undermines your argument, since it now seems to be a fluke that the authors made that point at all and that, in general, you think that the work of the authors is work rejecting.
    As I've said repeatedly, there aren't any. I cannot use mathematics to prove that there is no literal time flowing through a clock.
    You are avoiding the real question. I was asking there about the "ersatz version of GR" that you describe. If such a thing exists, you need to demonstrate what it is, what the real version is, and what the difference between them is. It would be nice, ideally, if you could show us where in Einstein's work (not his commentary) the difference lies. This involves showing us the mathematics of the physics, since that is how the work of physics gets done. In order to do his physics, Einstein developed a new field of mathematics. He did this because it was necessary to produce a meaningful physics. If we ignore that, then we ignore his work and insult his memory.
    I'm not. I'm not some my-theory guy.
    You are offering us a claim that there exists an "ersatz version of GR" and a supposedly true version of GR. That is your theory. So far, you have done nothing to defend this theory as you have not addressed the content of GR in a serious way.
    You can reject it if you wish, but others aren't rejecting it. What I'm saying is gaining ground.
    That is a shame, since you seem to be offering us a return to pre-Enlightenment lives where science uses the principles of alchemy and does not use mathematics. I respect the correct reasoning in the correct disciplines, in this case, I cannot accept your textual analysis in the place of real physics.
    [PhysBang: " At this point, it appears that you have no real physics theory, just a claim about the speed of light."] Correct. A claim that is backed up by the evidence and other authors including Einstein.
    Well, I suppose it is a step forward for you to admit that you are not making physics claims.
    My claim is supported by the evidence. Your conviction isn't.
    It is interesting that you use the word "evidence" and not the phrase "measurement evidence". I suppose that this is a sign that you are embracing that you are not doing physics and that you are simply doing a (limited) textual analysis. My conviction that Einstein's work was more complicated than you present is based on the textual analysis of seeing that there is a great deal of mathematics there on this subject that you do not address.
    You're saying nothing. You have no counterargument, all you have is rejection, and you're clutching at straws to reject what I'm telling you and dismiss not just me, but Einstein too.
    That doesn't seem true. As I have said, with the "ersatz version of GR" that you say is incorrect, people can build working machines and can successfully compute and use complicated trajectories. You, on the other hand, offer us what you admit is not a physics claim but merely a claim about the speed of light. That claim cannot be used in any meaningful way.

    It is actually funny that the only case that you predict in one with NIST optical clocks 30cm apart from each other. And even in that case you give a vague prediction. If we were to compare your statement to the rich theory of the "ersatz version of GR", then the evidence in physics clearly lies with the "ersatz version of GR".

    It is funny that you want to lead people away from the practicality of mathematical physics that built things like optical clocks towards the kind of ineffectual textual-analysis in a theological vein that seemed to dominate the Dark Ages.
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    Quote Originally Posted by SpeedFreek View Post
    This is an inappropriate comment, x0x, an ad hominem. Attack the argument, not the person making it. Consider this a final warning or be prepared to take some time off.
    Why?

    Farsight quotes so many things, cherry picking, that one can be afraid to read the same articles, even if in full they can educate.

    Farsight is doing more damage than x0x. And has been for like over a decade?
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    Quote Originally Posted by Beer w/Straw View Post
    Why?

    Farsight quotes so many things, cherry picking, that one can be afraid to read the same articles, even if in full they can educate.

    Farsight is doing more damage than x0x. And has been for like over a decade?
    You shouldn't be afraid to read the articles. You should read them and make your own conclusions. You should never take anyone's word for what their real meaning is. I find often that many articles are quoted but it is clear that the quoter has not read it to the end for example.....
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    In short:

    Farsight's attempt to ruin my life.
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    Quote Originally Posted by Beer w/Straw View Post
    Why?

    Farsight quotes so many things, cherry picking, that one can be afraid to read the same articles, even if in full they can educate.

    Farsight is doing more damage than x0x. And has been for like over a decade?
    In a science forum it is appropriate to correct a poster, to show them where they are going wrong, to disagree with them and give your reasoning for doing so. It is not appropriate to call them names or hurl abuse at them.

    You can explain why their words are nonsense, but you cannot call them crazy. You can show where their argument is lacking, but you cannot call them a poser.

    Attack the words, not the person posting them.
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    Quote Originally Posted by Jilan
    You should never take anyone's word for what their real meaning is.
    So I will not take your word for that.

    You see ? it is very easy to ruin any arguments. In fact there IS time were you should, and time were you should not, and probably time you should do both AND neither. And all that depends on your FoR.

    Quote Originally Posted by SpeedFreek
    Attack the words, not the person posting them.
    That is a rule impossible to follow. Because it is also relative.

    Some person will consider to be "attacked", wen you challenge their words. In fact you cannot do the later without doing the former.
    At the other range of the distribution other persons will not even feel attacked, when they words are "corrected". They will welcome it gracefully.

    Anyway that rule is easy to implement. You can transform any phrase as to follow that rule. BTW post #39 follow that rule.
    It contains some statement about the difficulty to do physics when your are simulating an knowledge and/or a willingness to respond to question.

    I can also observe that every thread with a certain person is always turning into semantics/rhetoric, not physics and even less logic.

    Now, I am honestly wondering if I have "attacked" a person or if I have just "describe his words".
    I kind of think, that on a internet forum were all is words, they are the same event.
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    I can'''t correct what I dob't know. Chemistry, Physics, lab work besides the classes including Linear Algebra, Calculus. You may want to excuse me as being uneducated and stupid. There are, however, pieces of shit that are going to infect the forum to the point that no one but cranks want to participate.
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    When I said "their" real meaning I meant of course the meaning of the articles. You should always assume the good faith of the posters unless have good reason to doubt them. In which case it's especially important to read the articles. Either way you should read the articles.....
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    Farsight can ruin articles by cherry-picking.
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    Quote Originally Posted by Farsight View Post
    It's done already and you know it, only it's called the coordinate speed of light.
    Show us how to calculate it in general. Repeating some specific solution does NOT count.

    Note that the elapsed time t displayed by an optical clock at some elevation is directly dependent on the coordinate speed of light at that elevation, because the optical clock is effectively counting some regular cyclical electromagnetic motion. Hence the well-know expression below gives the ratio between the speed of light at two elevations:

    That is ONE solution with ONE coordinate system and with ONE set of observers. I'm VERY disappointed.

    What won't do is dismissing what Einstein Koks Wright Shapiro Magueijo Moffat and Stenger said as "scriptural exegesis".
    Or more precisely, your interpretations of isolated quotations. Farsight, that fits perfectly with my description of your argument style.

    You've got that back to front. The speed of light, in space made inhomogeneous by a concentration of energy, determines the geometry of the abstract mathematical model called spacetime.
    Space-time is no more an "abstract mathematical model" than any other mathematical theory. Farsight, you keep on ignoring the significance of Lorentz invariance. When I post about the mathematics of it, you accuse me of distracting people with mathematics, so I will use your favorite sort of argument: quotes from your scriptures. Hermann Minkowski, Space and Time, 1909 (translation at Wikisource): "The concepts about time and space, which I would like to develop before you today, have grown on experimental physical grounds. Herein lies their strength. Their tendency is radical. Henceforth, space for itself, and time for itself shall completely reduce to a mere shadow, and only some sort of union of the two shall preserve independence."

    Again that's back to front. It's a curvature in your metric. A curvature in your plot of measurements. It's like what I said in the gravity thread. The clocks nearer the Earth dont run slower because your plot is of clock rates is curved. They run slower because light goes slower, because space is different. Because the speed of light varies with position.
    Show us the math behind that. Show us how one gets speed-of-light variations from gravity, then space-time curvature from speed-of-light variations. Show us *mathematically*.

    But what we don't perceive are world lines and light cones.
    We don't perceive coordinate axes either.

    Quote Originally Posted by Farsight View Post
    Yes. The second varies with gravitational potential, with elevation, we call it gravitational time dilation.
    Can you show that one gets a gravitational potential *in general*? From general-relativity first principles. You will have to use mathematics without doing scriptural exegesis, however.

    Quote Originally Posted by Farsight View Post
    I'm only rejecting one, because Einstein rejected it. Here's the quotes:

    [I]1911: "If we call the velocity of light at the origin of coordinates c₀, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = c₀(1 + Φ/c).
    That was his old theory, which he later rejected. Farsight, that's a scriptural percussionist's sort of argument.

    (other scripture quotes snipped)
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    Quote Originally Posted by Beer w/Straw View Post
    Farsight can ruin articles by cherry-picking.
    He can't ruin the articles, he can somewhat tarnish the reputation of the authors to the extent that they are identified with Farsight. I don't think that's too much, though.

    One can point out where someone is cherry-picking. If this person denies it, if there is always a gross conflict between what they cherry-pick and the full scientific articles they choose, their position should continue to look worse and worse.

    Sometimes, a poster sites true cranks. It's often to just ignore those references and focus on the claims that the poster makes. If all someone can produce to support a point are crank articles, then they will have other conceptual flaws. Here is a good list of poor references: List of Internet kooks - RationalWiki
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    All of got is a textbook. And this asshole wants to to throw everything at me whilst I'm unprepared and working several different things?

    Can I even trust what he says? Do I have to read it with a grain of salt?
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    Quote Originally Posted by SpeedFreek View Post
    In a science forum it is appropriate to correct a poster, to show them where they are going wrong, to disagree with them and give your reasoning for doing so. It is not appropriate to call them names or hurl abuse at them.

    You can explain why their words are nonsense, but you cannot call them crazy. You can show where their argument is lacking, but you cannot call them a poser.

    Attack the words, not the person posting them.
    Sorry, I got fed up with the many years worth of anti-mainstream posts. It is not worth answering Farsight, he will just continue posting the same fringe stuff polluting the forum. Since his threads already reside in Trash, I will refrain from answering.
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    If I get suspended for my comments, just ban me forever.
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    Quote Originally Posted by Beer w/Straw View Post
    If I get suspended for my comments, just ban me forever.
    I do understand your frustration, don't worry. But we cannot allow people to throw insults around and allow threads to descend into slanging matches, so I hope you can understand that this kind of behaviour has to stop.

    Farsights contentious threads and comments have been moved to the Personal Theories forum, where they belong.

    Rather than looking backwards, let's see if we can move forward now, eh?
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    Quote Originally Posted by SpeedFreek View Post
    That's the COORDINATE speed, not the PROPER speed.
    The coordinate speed is the speed. The proper speed is the locally measured speed, which is constant by definition, because of the tautology.

    Quote Originally Posted by SpeedFreek View Post
    The lower the gravitational potential, the greater the gravitational time-dilation. An observer at a low gravitational potential (i.e. near a gravitational source) will measure the speed of light, locally, to be 299792458 m/s. An observer at a higher gravitational potential (i.e. at a greater distance from the gravitational source) will also measure the speed of light, locally, to be 299792458 m/s.
    Yes. And each will define his second as the duration of 9192631770 microwaves passing him by. Then they each use their second to measure the speed of microwaves passing by.

    Quote Originally Posted by SpeedFreek View Post
    The observer at the lower gravitational potential will calculate that a clock at a higher gravitational potential is "ticking faster" than their own, and vice versa.
    Yes, even when it's an optical clock or a parallel-mirror light clock. And he knows that there isn't any time flowing in these clocks.

    Quote Originally Posted by SpeedFreek View Post
    Of course, from the frame of the lower clock, the upper clock goes faster.
    And from the frame of the upper clock. All observers will agree that clocks go slower when they're lower. GR time dilation isn't symmetrical like SR time dilation.

    Quote Originally Posted by SpeedFreek View Post
    Now let's look at this in different terms - constant acceleration (remember the equivalence principle here). We can use Rinder coordinates for this, and what do we find? We find that, at a certain distance from the constantly accelerating frame, the COORDINATE speed of light is ZERO. This is known as the "Rindler Horizon".
    Yes, we know about this. But when we look at the fast-moving observer, we don't see a dark thing following him. We don't see light grind to a halt because he's moving fast through space.

    Quote Originally Posted by SpeedFreek View Post
    It is purely a coordinate effect. If we had another observer in an inertial frame of reference sitting at the same coordinates as the accelerating observer calculates the Rindler horizon to be, they certainly would NOT measure the speed of light to be ZERO, would they?
    No. But like I said, for GR time dilation everybody agrees that the lower clock goes slower. It isn't just some coordinate effect.

    Quote Originally Posted by SpeedFreek
    What you are referring to is the coordinate speed of light, which can indeed vary. We know this.
    But what you don't know is that Einstein called it the speed of light.

    Quote Originally Posted by SpeedFreek
    But nobody ever measures the proper speed of light to vary.
    Of course they don't. Because when light goes slower you go slower too, and your second is bigger because you define it using the motion of light. Then you use it to measure the motion of light. Tautology!

    Quote Originally Posted by SpeedFreek
    The speed of light varies with position FROM THE OBSERVER. Locally to the observer, it never varies.
    It varies in a measureable fashion within a region of only 30cm. That's less than the metre you use when quoting the "local" speed of light. If you had more accurate optical clocks you'd find it varied within 3cm or 3mm or 3 micrometres. Because there's a gradient in the speed of light in the room you're in. If there wasn't there wouldn't be any gravitational field.

    Quote Originally Posted by SpeedFreek
    We can take this even further if we invoke cosmological models like the current consensus model - LCDM concordance. Here, the proper speed of light is always c, but the coordinate speed of light on our past light cone was NEGATIVE for the first 4.5 billion years of the history of our universe. This is no great insight. Nor does it have any bearing on how time actually passed during the history of our universe.
    A negative speed is not a real speed. That's a distraction.
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    Quote Originally Posted by SpeedFreek View Post
    I have heard that "tautology" argument before. Some misguided people seem to think that, because technological developments in our apparatus allowed measurements so accurate that we came to a point where we defined the length of a metre in terms of the speed of light, the laws of physics suddenly changed. They didn't.
    The definition only clarified the tautology. Or should have done. The tautology applied to previous definitions of the metre because light and matter are of the "same essence". See the Wikipedia gravitational time dilation article and note this:

    "The speed of light in a locale is always equal to c according to the observer who is there. The stationary observer's perspective corresponds to the local proper time. Every infinitesimal region of space time may have its own proper time that corresponds to the gravitational time dilation there, where electromagnetic radiation and matter may be equally affected, since they are made of the same essence [5] (as shown in many tests involving the famous equation E=mc)."

    Note that PhysBang has already conceded that the speed of light is only constant in an infinitesimal region. It isn't constant in the room you're in.
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    Quote Originally Posted by Boing3000 View Post
    No he did not. So you agree with something he did not say. In fact he said the contrary. So you are contradicting Einstein theory, and factual experiment.
    No I'm not. Einstein said this in 1916:

    "In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position".

    And I will reiterate that whilst the word velocity appears in the English translations, what Einstein actually said was "die Ausbreitungsgeschwindigkeit des Lichtes mit dem Orte variiert". That translates to "the propagation speed of the light with the place varies". And he said "one of the two fundamental assumptions in the special theory of relativity". He's saying the SR postulate doesn't apply for GR. Hence Don Koks said this in the Baez article:

    "Einstein talked about the speed of light changing in his new theory. In his 1920 book "Relativity: the special and general theory" he wrote: "... according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [...] cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity [Einstein means speed here] of propagation of light varies with position." This difference in speeds is precisely that referred to above by ceiling and floor observers."

    So I am not contradicting Einstein. Nor am I contradicting factual experiment such as the Shapiro delay where Irwin Shapiro said this:

    "The proposed experiment was designed to verify the prediction that the speed of propagation of a light ray decreases as it passes through a region of decreasing gravitational potential"

    Quote Originally Posted by Boing3000 View Post
    And back to cognitive dissonance...
    Not on my part.
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    Quote Originally Posted by PhysBang View Post
    ...So you are going to take one quotation out of an entire paper, ignore the rest of the paper and the specific citation that they make in the quotation because the details might not coincide with your claims. This is what we call cherry-picking; it is a fallacious form of argument...
    No, your cherry-picking claim is fallacious, because I'm referring to hard scientific evidence along with multiple Einstein quotes and to Shapiro, Wright, Koks, Stenger, Magueijo, Moffat, and so on. And you have already conceded that the speed of light is only constant in an infinitesimal region. See this post. So your whole argument is fallacious.
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    I think we are going round in circles a bit here. Of course the speed of light at the bottom of the room will be less than the speed of light at the top of the room measured by the same observer at the top of the room. This is because they are not in the same reference frame. (Even if they are only 30cm apart)
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    Quote Originally Posted by lpetrich View Post
    Show us how to calculate it in general. Repeating some specific solution does NOT count.
    It's very simple, you remember that clocks don't literally measure the flow of time, that t relates to the number of reflections in a parallel-mirror light-clock, and therefore denotes the relative speed of light at that location. It's that simple. I can't show you any more or tell you any more.

    Quote Originally Posted by lpetrich View Post
    That is ONE solution with ONE coordinate system and with ONE set of observers. I'm VERY disappointed.
    It's a fine example. Methinks you are disappointed that I handled the question with aplomb.

    Quote Originally Posted by lpetrich View Post
    Or more precisely, your interpretations of isolated quotations. Farsight, that fits perfectly with my description of your argument style.
    Only it isn't isolated quotations, it's hard scientific evidence too. And it isn't just Einstein. It's Koks and Magueijo and Moffat and Wright and Shapiro and Stenger.

    Quote Originally Posted by lpetrich View Post
    Space-time is no more an "abstract mathematical model" than any other mathematical theory. Farsight, you keep on ignoring the significance of Lorentz invariance. When I post about the mathematics of it, you accuse me of distracting people with mathematics, so I will use your favorite sort of argument: quotes from your scriptures. Hermann Minkowski, Space and Time, 1909 (translation at Wikisource): "The concepts about time and space, which I would like to develop before you today, have grown on experimental physical grounds. Herein lies their strength. Their tendency is radical. Henceforth, space for itself, and time for itself shall completely reduce to a mere shadow, and only some sort of union of the two shall preserve independence."
    Quote all you like, spacetime is still static. It isn't what space is.

    Quote Originally Posted by lpetrich View Post
    Show us the math behind that. Show us how one gets speed-of-light variations from gravity, then space-time curvature from speed-of-light variations. Show us *mathematically*.
    I can't. Mathematics can't show you this. If it could you would know it already. I need to show you hard scientific evidence, like the absence of time flowing through optical clocks and the lower clock going slower. And you need to pay attention to it instead of being lost in abstraction.

    Quote Originally Posted by lpetrich View Post
    Can you show that one gets a gravitational potential *in general*? From general-relativity first principles. You will have to use mathematics without doing scriptural exegesis, however.
    I don't know. Maybe. But what's the point? Nobody doubts gravitational potential.

    Quote Originally Posted by lpetrich View Post
    That was his old theory, which he later rejected. Farsight, that's a scriptural percussionist's sort of argument.

    Other scripture quotes snipped
    They aren't scripture quotes. Einstein said what he said:

    1911: "If we call the velocity of light at the origin of coordinates c₀, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = c₀(1 + Φ/c).

    1912: "On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential".

    1913: "I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis".

    1915: "the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned".

    1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position.


    Dismissing what Einstein said as "scripture" doesn't help your case, lpetrich. Not one bit.
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    Quote Originally Posted by SpeedFreek View Post
    Farsights contentious threads and comments have been moved to the Personal Theories forum, where they belong.
    They don't belong there. I'm not some "my theory" guy. I'm telling you what Einstein said. And I'm telling you about the hard scientific evidence and what those other guys said. And you can't find the flaw in what I'm saying. If I were to ask you why does the lower optical clock go slower you'd probably say because the flow of time is slower. And then I'd say show me this flow of time. And you can't. Nor can anybody else. Because I'm right about all this. So move this thread to the main forum.

    Quote Originally Posted by Jilan View Post
    I think we are going round in circles a bit here. Of course the speed of light at the bottom of the room will be less than the speed of light at the top of the room measured by the same observer at the top of the room. This is because they are not in the same reference frame. (Even if they are only 30cm apart)
    Can you show me those two different reference frames? No. There aren't two actual reference frames in the room you're in separated by 30cm. There is no multiplicity of reference frames 1mm apart, or 1 nanometre apart. They do not exist. They are abstract things. Optical clocks aren't. and there isn't any time flowing through them. So why does the lower clock go slower? Because the speed of light varies with position. Just like Einstein said.
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    Farsight, of course they are different reference frames, no matter how small the difference between them. They are accelerating at different rates, they are not the same reference frame.
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    Those reference frames don't actually exist, Jilan. They are abstract things, not real things. What does exist is the room, and the two optical clocks in it. One is 30cm below the other, and it's going slower. Something else that doesn't exist is time flowing. There isn't any actual time flowing through either clock. So the lower clock doesn't go slower because time goes slower. Why does it go slower? Let's ask my Uncle Albert:

    Q: Uncle Albert, we've got two optical clocks. The lower clock is going slower. Why?
    A: Hoh, because the speed of light varies with position. Ja.
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    Quote Originally Posted by Farsight View Post
    Note that PhysBang has already conceded that the speed of light is only constant in an infinitesimal region. It isn't constant in the room you're in.
    Note that PhysBang knew the limitations on the speed of lights well before he ever heard of Farsight and before Farsight started his weird crusade (at least on the internet).

    But please also know that Farsight is lying when he says that I believe that the speed of light is only constant in an infinitesimal region. As he knows, I believe that there are a number of coordinate systems and physical scenarios where the speed of light can be constant for an extended region. At least I believe this as strongly as I believe that GR is a good approximation to the physics of the universe.

    It is not the first time that Farsight has lied, not even the first time he has personally attacked me by lying about what I have said, and it is a reason to take what he says about other sources as doubtful. However, let's focus on Farsight's "arguments".

    Quote Originally Posted by Farsight View Post
    No, your cherry-picking claim is fallacious, because I'm referring to hard scientific evidence
    In this case, you are ignoring all the evidence that Magueijo and Moffat wrote about except for the word "tautology". That is a paradigm example of cherry-picking. But this is irrelevant to your dodging of the question: what is the difference between the Lorentz-Symmetry-violating VSL theories discussed by Magueijo, Moffat, and Ellis and your theory? You brought these people into the discussion and they all claim that variable speed of light theories have to violate Lorentz symmetry, so you need to explain this important aspect of their papers.

    along with multiple Einstein quotes and to Shapiro, Wright, Koks, Stenger, Magueijo, Moffat, and so on.
    So far, all you have is quotes. SO please show us the equations that govern your reasoning so that we can use measurement evidence to consider them.

    And you have already conceded that the speed of light is only constant in an infinitesimal region. See this post.
    I know that you have some problem telling the truth about what people say about physics, but thank you for providing the link so that people can see that you aren't telling the truth in this case. I wrote, "The same is true for general relativity, developed in 1915, which holds that the speed of light is constant at any infinitesimal region of a coordinate system." This statement does not imply that GR only holds that the speed of light is constant for infinitesimal regions.

    Still, if all you want to say is that the speed of light is sometimes different from c for finite distances in some systems of coordinates, then we can agree on that. However, you also clearly have other claims that accompany this claim, claims that you seemingly refuse to defend.
    Quote Originally Posted by Farsight View Post
    It's very simple, you remember that clocks don't literally measure the flow of time, that t relates to the number of reflections in a parallel-mirror light-clock, and therefore denotes the relative speed of light at that location. It's that simple. I can't show you any more or tell you any more.
    Sadly, your theory on this subject, explicitly stated above, fails in comparison to contemporary relativity theory as outlined first by Einstein, since the contemporary theory has much more to show and tell. Physics is about descriptions that can be compared in detail to measurement evidence where the parameters of the physical theory can be closely tied to measurements of physical phenomena. There is much more and much more details that can be said about measuring time.
    It's a fine example. Methinks you are disappointed that I handled the question with aplomb.
    You seem to have handled the question only with cut-and-paste. You have been asked many times to show how your ideas work in a fleshed-out example; you have failed to respond to these requests. Since your ideas cannot be compared to measurements of physical systems, your ideas cannot be considered physics.
    I don't know. Maybe. But what's the point? Nobody doubts gravitational potential.
    The problem is not that people doubt gravitational potential, what people doubt is that it has anything to do with your ideas. Your continued (over a decade long) refusal to produce real applications or examples for your ideas indicates that it is not physics but fantasy. This is why nobody doubts that you "don't know."
    Quote Originally Posted by Farsight View Post
    Can you show me those two different reference frames? No. There aren't two actual reference frames in the room you're in separated by 30cm. There is no multiplicity of reference frames 1mm apart, or 1 nanometre apart. They do not exist. They are abstract things. Optical clocks aren't. and there isn't any time flowing through them. So why does the lower clock go slower? Because the speed of light varies with position. Just like Einstein said.
    If this is the case, then it should be easy for you to show us explicitly where Einstein does this in an example. However, I do not doubt that you will fail to do this.

    Since you like dodging questions, let's bring my questions back so that we can see you dodging them again.
    Quote Originally Posted by Farsight View Post
    They described a tautology. That's it.
    So you are going to take one quotation out of an entire paper, ignore the rest of the paper and the specific citation that they make in the quotation because the details might not coincide with your claims. This is what we call cherry-picking; it is a fallacious form of argument. At the very least, you have to distinguish between your variable speed of light theory and what those authors describe as a variable speed of light theory.
    I haven't given the reverse of what Einstein actually says. Einstein said a curvature of rays of light can only occur when the speed of light varies with position. The word velocity appears in the English translation but as Don Koks said, Einstein meant speed. This is obvious because he was referring to the SR postulate.
    If this is the case, it should be easy for you to demonstrate the varying of the speed of light by position that Einstein used.
    It just isn't relevant. What is, is the tautology described by Magueijo and Moffat.
    Surely those authors believe that the remainder of their paper on this very topic is relevant. If you cite their paper where they go into great detail on this topic, then you should at least say why everything else in their paper is incorrect. It does a disservice to your reader to make it look like the paper is something that is an authority on the subject when in fact you believe that the authors are very wrong on this very subject. This undermines your argument, since it now seems to be a fluke that the authors made that point at all and that, in general, you think that the work of the authors is work rejecting.
    As I've said repeatedly, there aren't any. I cannot use mathematics to prove that there is no literal time flowing through a clock.
    You are avoiding the real question. I was asking there about the "ersatz version of GR" that you describe. If such a thing exists, you need to demonstrate what it is, what the real version is, and what the difference between them is. It would be nice, ideally, if you could show us where in Einstein's work (not his commentary) the difference lies. This involves showing us the mathematics of the physics, since that is how the work of physics gets done. In order to do his physics, Einstein developed a new field of mathematics. He did this because it was necessary to produce a meaningful physics. If we ignore that, then we ignore his work and insult his memory.
    I'm not. I'm not some my-theory guy.
    You are offering us a claim that there exists an "ersatz version of GR" and a supposedly true version of GR. That is your theory. So far, you have done nothing to defend this theory as you have not addressed the content of GR in a serious way.
    You can reject it if you wish, but others aren't rejecting it. What I'm saying is gaining ground.
    That is a shame, since you seem to be offering us a return to pre-Enlightenment lives where science uses the principles of alchemy and does not use mathematics. I respect the correct reasoning in the correct disciplines, in this case, I cannot accept your textual analysis in the place of real physics.
    [PhysBang: " At this point, it appears that you have no real physics theory, just a claim about the speed of light."] Correct. A claim that is backed up by the evidence and other authors including Einstein.
    Well, I suppose it is a step forward for you to admit that you are not making physics claims.
    My claim is supported by the evidence. Your conviction isn't.
    It is interesting that you use the word "evidence" and not the phrase "measurement evidence". I suppose that this is a sign that you are embracing that you are not doing physics and that you are simply doing a (limited) textual analysis. My conviction that Einstein's work was more complicated than you present is based on the textual analysis of seeing that there is a great deal of mathematics there on this subject that you do not address.
    You're saying nothing. You have no counterargument, all you have is rejection, and you're clutching at straws to reject what I'm telling you and dismiss not just me, but Einstein too.
    That doesn't seem true. As I have said, with the "ersatz version of GR" that you say is incorrect, people can build working machines and can successfully compute and use complicated trajectories. You, on the other hand, offer us what you admit is not a physics claim but merely a claim about the speed of light. That claim cannot be used in any meaningful way.

    It is actually funny that the only case that you predict in one with NIST optical clocks 30cm apart from each other. And even in that case you give a vague prediction. If we were to compare your statement to the rich theory of the "ersatz version of GR", then the evidence in physics clearly lies with the "ersatz version of GR".

    It is funny that you want to lead people away from the practicality of mathematical physics that built things like optical clocks towards the kind of ineffectual textual-analysis in a theological vein that seemed to dominate the Dark Ages.
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    Quote Originally Posted by PhysBang View Post
    But please also know that Farsight is lying when he says that I believe that the speed of light is only constant in an infinitesimal region. As he knows, I believe that there are a number of coordinate systems and physical scenarios where the speed of light can be constant for an extended region. At least I believe this as strongly as I believe that GR is a good approximation to the physics of the universe.
    You said what you said, I referred to the post here. I'm not lying. You said this:

    "In a sense, this was done in 1905, when Einstein developed special relativity. This constancy of the speed of light is a postulate of the theory, so it is "shown" through the effectiveness and practicality of the theory. The same is true for general relativity, developed in 1915, which holds that the speed of light is constant at any infinitesimal region of a coordinate system."

    Quote Originally Posted by PhysBang View Post
    It is not the first time that Farsight has lied, not even the first time he has personally attacked me
    I haven't lied, and it's you who is personally attacking me, again.

    Quote Originally Posted by PhysBang
    I know that you have some problem telling the truth about what people say about physics...
    And again and again. The rest of your post is one long ad-hominem diatribe that does not address the subject at hand. Which is that the speed of light varies with position.

    Quote Originally Posted by PhysBang View Post
    It is funny that you want to lead people away from the practicality of mathematical physics that built things like optical clocks towards the kind of ineffectual textual-analysis in a theological vein that seemed to dominate the Dark Ages.
    I want people to understand relativity to break out of the dark age we're in where there's been no significant scientific progress for fifty years and physics funding is under growing threat. You stand four square against me.
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    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by KJW View Post
    All I'm saying is that 299792458 ms1 is the same as 299792458 ms1 and 1 s is the same as 1 s. It is up to you to specify how they are not (not why they are not, btw). Your reply doesn't address the question that I am asking and appears to me to be a diversion.
    It's no diversion.
    And yet you did not answer the question I asked. Then you continued with more of not answering my question.


    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by KJW View Post
    No, that is not enough. I asked for precision. For example, you tell me one is slower than the other, but by how much? Can the difference be measured and be quantified?
    Of course it can. The NIST optical clocks demonstrate a measurable difference when one is only 30cm above the other
    You didn't answer the question "by how much?" or give any quantification of the difference. However, what you did say doesn't conform to the claim you are making. You claim that the lower NIST optical clock is slower than the upper NIST optical clock, but in fact the lower NIST optical clock indicates less elapsed time than the upper NIST optical clock. Note that "less elapsed time" is consistent with general relativity, whereas "slower" is an inference that you have made that violates the principle of general relativity. You have also claimed that the lower clock is slower because the gravitational potential is lower, but just as when you open a clock, you don't see time flowing through it, you also don't see any mechanism for detecting gravitational potential.


    Quote Originally Posted by Farsight View Post
    You know that a clock runs slower when its lower. You know that everything runs slower when it's lower, including you. You know that we call this phenomenon gravitational time dilation. You know that a second lasts longer when time dilation is occurring. Surely? This is something you should be totally familiar with and comfortable with.
    I'm familiar with gravitational time dilation, but disagree with your interpretation. When you say a clock ticks slower, I say a clock ticks less time.
    A tensor equation that is valid in any coordinate system is valid in every coordinate system.
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    Quote Originally Posted by Farsight
    I'm not lying. You said this:
    So you admit your lies now ? A mistake probably.
    Nowhere in the quote anybody said "...is only constant.." You are the only one. Even in the last phrase, it is written"holds that the speed of light is constant at any infinitesimal region of a coordinate system." Which of course does not exclude it can be constant in extended region of space...

    Quote Originally Posted by SpeedFreek
    Rather than looking backwards, let's see if we can move forward now, eh?
    If you really believe this is the way to go, Farsight should be banned from the site.

    Here is another lie from the "I am not a my theory guy" is writing on another thread:
    Quote Originally Posted by Farsight
    There isn't any motion through spacetime. It's the block universe. All times at once. It's static.
    And here is how he define motion:
    Quote Originally Posted by Farsight
    Empirically. You hold your hands up a yard apart and say that's distance then you waggle your hands and say that's motion.
    I have great difficulty in understanding why he is still allowed to post here, or anywhere but cranks site.
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    Quote Originally Posted by Farsight View Post
    Note that PhysBang has already conceded that the speed of light is only constant in an infinitesimal region. It isn't constant in the room you're in.
    Note that PhysBang knew the limitations on the speed of lights well before he ever heard of Farsight and before Farsight started his weird crusade (at least on the internet).

    But please also know that Farsight is lying when he says that I believe that the speed of light is only constant in an infinitesimal region. As he knows, I believe that there are a number of coordinate systems and physical scenarios where the speed of light can be constant for an extended region. At least I believe this as strongly as I believe that GR is a good approximation to the physics of the universe.

    It is not the first time that Farsight has lied, not even the first time he has personally attacked me by lying about what I have said, and it is a reason to take what he says about other sources as doubtful. However, let's focus on Farsight's "arguments".

    Quote Originally Posted by Farsight View Post
    No, your cherry-picking claim is fallacious, because I'm referring to hard scientific evidence
    In this case, you are ignoring all the evidence that Magueijo and Moffat wrote about except for the word "tautology". That is a paradigm example of cherry-picking. But this is irrelevant to your dodging of the question: what is the difference between the Lorentz-Symmetry-violating VSL theories discussed by Magueijo, Moffat, and Ellis and your theory? You brought these people into the discussion and they all claim that variable speed of light theories have to violate Lorentz symmetry, so you need to explain this important aspect of their papers.

    along with multiple Einstein quotes and to Shapiro, Wright, Koks, Stenger, Magueijo, Moffat, and so on.
    So far, all you have is quotes. SO please show us the equations that govern your reasoning so that we can use measurement evidence to consider them.

    And you have already conceded that the speed of light is only constant in an infinitesimal region. See this post.
    I know that you have some problem telling the truth about what people say about physics, but thank you for providing the link so that people can see that you aren't telling the truth in this case. I wrote, "The same is true for general relativity, developed in 1915, which holds that the speed of light is constant at any infinitesimal region of a coordinate system." This statement does not imply that GR only holds that the speed of light is constant for infinitesimal regions.

    Still, if all you want to say is that the speed of light is sometimes different from c for finite distances in some systems of coordinates, then we can agree on that. However, you also clearly have other claims that accompany this claim, claims that you seemingly refuse to defend.
    Quote Originally Posted by Farsight View Post
    It's very simple, you remember that clocks don't literally measure the flow of time, that t relates to the number of reflections in a parallel-mirror light-clock, and therefore denotes the relative speed of light at that location. It's that simple. I can't show you any more or tell you any more.
    Sadly, your theory on this subject, explicitly stated above, fails in comparison to contemporary relativity theory as outlined first by Einstein, since the contemporary theory has much more to show and tell. Physics is about descriptions that can be compared in detail to measurement evidence where the parameters of the physical theory can be closely tied to measurements of physical phenomena. There is much more and much more details that can be said about measuring time.
    It's a fine example. Methinks you are disappointed that I handled the question with aplomb.
    You seem to have handled the question only with cut-and-paste. You have been asked many times to show how your ideas work in a fleshed-out example; you have failed to respond to these requests. Since your ideas cannot be compared to measurements of physical systems, your ideas cannot be considered physics.
    I don't know. Maybe. But what's the point? Nobody doubts gravitational potential.
    The problem is not that people doubt gravitational potential, what people doubt is that it has anything to do with your ideas. Your continued (over a decade long) refusal to produce real applications or examples for your ideas indicates that it is not physics but fantasy. This is why nobody doubts that you "don't know."
    Quote Originally Posted by Farsight View Post
    Can you show me those two different reference frames? No. There aren't two actual reference frames in the room you're in separated by 30cm. There is no multiplicity of reference frames 1mm apart, or 1 nanometre apart. They do not exist. They are abstract things. Optical clocks aren't. and there isn't any time flowing through them. So why does the lower clock go slower? Because the speed of light varies with position. Just like Einstein said.
    If this is the case, then it should be easy for you to show us explicitly where Einstein does this in an example. However, I do not doubt that you will fail to do this.

    Since you like dodging questions, let's bring my questions back so that we can see you dodging them again.
    Quote Originally Posted by Farsight View Post
    They described a tautology. That's it.
    So you are going to take one quotation out of an entire paper, ignore the rest of the paper and the specific citation that they make in the quotation because the details might not coincide with your claims. This is what we call cherry-picking; it is a fallacious form of argument. At the very least, you have to distinguish between your variable speed of light theory and what those authors describe as a variable speed of light theory.
    I haven't given the reverse of what Einstein actually says. Einstein said a curvature of rays of light can only occur when the speed of light varies with position. The word velocity appears in the English translation but as Don Koks said, Einstein meant speed. This is obvious because he was referring to the SR postulate.
    If this is the case, it should be easy for you to demonstrate the varying of the speed of light by position that Einstein used.
    It just isn't relevant. What is, is the tautology described by Magueijo and Moffat.
    Surely those authors believe that the remainder of their paper on this very topic is relevant. If you cite their paper where they go into great detail on this topic, then you should at least say why everything else in their paper is incorrect. It does a disservice to your reader to make it look like the paper is something that is an authority on the subject when in fact you believe that the authors are very wrong on this very subject. This undermines your argument, since it now seems to be a fluke that the authors made that point at all and that, in general, you think that the work of the authors is work rejecting.
    As I've said repeatedly, there aren't any. I cannot use mathematics to prove that there is no literal time flowing through a clock.
    You are avoiding the real question. I was asking there about the "ersatz version of GR" that you describe. If such a thing exists, you need to demonstrate what it is, what the real version is, and what the difference between them is. It would be nice, ideally, if you could show us where in Einstein's work (not his commentary) the difference lies. This involves showing us the mathematics of the physics, since that is how the work of physics gets done. In order to do his physics, Einstein developed a new field of mathematics. He did this because it was necessary to produce a meaningful physics. If we ignore that, then we ignore his work and insult his memory.
    I'm not. I'm not some my-theory guy.
    You are offering us a claim that there exists an "ersatz version of GR" and a supposedly true version of GR. That is your theory. So far, you have done nothing to defend this theory as you have not addressed the content of GR in a serious way.
    You can reject it if you wish, but others aren't rejecting it. What I'm saying is gaining ground.
    That is a shame, since you seem to be offering us a return to pre-Enlightenment lives where science uses the principles of alchemy and does not use mathematics. I respect the correct reasoning in the correct disciplines, in this case, I cannot accept your textual analysis in the place of real physics.
    [PhysBang: " At this point, it appears that you have no real physics theory, just a claim about the speed of light."] Correct. A claim that is backed up by the evidence and other authors including Einstein.
    Well, I suppose it is a step forward for you to admit that you are not making physics claims.
    My claim is supported by the evidence. Your conviction isn't.
    It is interesting that you use the word "evidence" and not the phrase "measurement evidence". I suppose that this is a sign that you are embracing that you are not doing physics and that you are simply doing a (limited) textual analysis. My conviction that Einstein's work was more complicated than you present is based on the textual analysis of seeing that there is a great deal of mathematics there on this subject that you do not address.
    You're saying nothing. You have no counterargument, all you have is rejection, and you're clutching at straws to reject what I'm telling you and dismiss not just me, but Einstein too.
    That doesn't seem true. As I have said, with the "ersatz version of GR" that you say is incorrect, people can build working machines and can successfully compute and use complicated trajectories. You, on the other hand, offer us what you admit is not a physics claim but merely a claim about the speed of light. That claim cannot be used in any meaningful way.

    It is actually funny that the only case that you predict in one with NIST optical clocks 30cm apart from each other. And even in that case you give a vague prediction. If we were to compare your statement to the rich theory of the "ersatz version of GR", then the evidence in physics clearly lies with the "ersatz version of GR".

    It is funny that you want to lead people away from the practicality of mathematical physics that built things like optical clocks towards the kind of ineffectual textual-analysis in a theological vein that seemed to dominate the Dark Ages.
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    Dear Farsight, I've heard your argument before...
    Quote Originally Posted by Farsight View Post
    1911: "If we call the velocity of light at the origin of coordinates c₀, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = c₀(1 + Φ/c).

    1912: "On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential".

    1913: "I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis".

    1915: "the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned".

    1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position.


    The word velocity appears in the English translations, but what Einstein actually said in 1916 was "die Ausbreitungsgeschwindigkeit des Lichtes mit dem Orte variiert". That translates to "the propagation speed of the light with the place varies". And note that he said "which constitutes one of the two fundamental assumptions in the special theory of relativity". He's saying the SR postulate doesn't apply for GR. It is to be abandoned. Hence Don Koks said this in the Baez article:

    "Einstein talked about the speed of light changing in his new theory. In his 1920 book "Relativity: the special and general theory" he wrote: "... according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [...] cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity [Einstein means speed here] of propagation of light varies with position." This difference in speeds is precisely that referred to above by ceiling and floor observers."

    I'm right, SpeedFreak. And all those people who told you the speed of light is absolutely constant, are wrong.
    ...from one Barry Setterfield, an Australian mathematician who now lives in Eugene, Oregon!

    He claims that the speed of light was once faster - and that 6,000 years ago it was INFINITELY fast. And so he connects his BS to creationism, not the BB kind but Bible-type creationism.

    Inaccurate past measurements cannot be taken as proving the speed of light to be variable!!!!!

    TFOLZO
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    Quote Originally Posted by KJW View Post
    And yet you did not answer the question I asked. Then you continued with more of not answering my question.
    I've answered all your questions. If you think I haven't or if you think I haven't answered it/them satisfactorily, please restate as necessary.

    Quote Originally Posted by KJW View Post
    You didn't answer the question "by how much?" or give any quantification of the difference.
    You know how much. You know how gravitational time dilation affects clocks. It's encapsulated in this image by Phil Fraundorf. All you need to appreciate is that the clock is going slower because the light goes slower. This applies to the GPS atomic clocks because they use microwaves. They're light clocks in the wider sense.

    Quote Originally Posted by KJW View Post
    However, what you did say doesn't conform to the claim you are making. You claim that the lower NIST optical clock is slower than the upper NIST optical clock, but in fact the lower NIST optical clock indicates less elapsed time than the upper NIST optical clock. Note that "less elapsed time" is consistent with general relativity, whereas "slower" is an inference that you have made that violates the principle of general relativity. You have also claimed that the lower clock is slower because the gravitational potential is lower, but just as when you open a clock, you don't see time flowing through it, you also don't see any mechanism for detecting gravitational potential.
    You're clutching at straws here. We all know what somebody means when they say the clock is slow. I haven't said anything at all that violates the principle of GR. Look, here's the Wikipedia time dilation article saying what I said:

    "The general theory of relativity describes how, for both observers, the clock that is closer to the gravitational mass, i.e. deeper in its "gravity well", appears to go more slowly than the clock that is more distant from the mass".

    Quote Originally Posted by KJW View Post
    I'm familiar with gravitational time dilation, but disagree with your interpretation. When you say a clock ticks slower, I say a clock ticks less time.
    A clock just accumulates some kind of regular cyclical motion of cogs or a crystal or something else and gives you a cumulative display that we call the time. It doesn't actually measure the flow of time. So "a clock ticks less time" doesn't relate too well with the empirical evidence. To get the right interpretation, you have to look hard at what a clock actually does. Especially when its a light clock. You might want to read the Don Koks Baez article again:

    "Einstein talked about the speed of light changing in his new theory. In his 1920 book "Relativity: the special and general theory" he wrote: "... according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [...] cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity [Einstein means speed here] of propagation of light varies with position." This difference in speeds is precisely that referred to above by ceiling and floor observers."
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    Quote Originally Posted by Farsight View Post
    Those reference frames don't actually exist, Jilan. They are abstract things, not real things. What does exist is the room, and the two optical clocks in it. One is 30cm below the other, and it's going slower. Something else that doesn't exist is time flowing. There isn't any actual time flowing through either clock. So the lower clock doesn't go slower because time goes slower. Why does it go slower? Let's ask my Uncle Albert:

    Q: Uncle Albert, we've got two optical clocks. The lower clock is going slower. Why?
    A: Hoh, because the speed of light varies with position. Ja.
    The coordinate speed of light varies with position. The local speed of light doesn't. Are you happy with that?
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    Quote Originally Posted by TFOLZO View Post
    Dear Farsight, I've heard your argument before...
    ...from one Barry Setterfield, an Australian mathematician who now lives in Eugene, Oregon!

    He claims that the speed of light was once faster - and that 6,000 years ago it was INFINITELY fast...
    That's got to be wrong. Think about the early universe. It was dense. It had a high energy density. A bit like a black hole. The coordinate speed is said to be zero at the event horizon. As for the creationism, I've had conversations with creationists. I've shown them the strata, the fossils, the radio-dating, and they dismiss everything. Nothing counts as evidence with those people. But get this: they are convictional because they are people, not because they are religious. And they aren't the only people like that.
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    In reply to Speedfreek, re: post #50 & #55.

    So....this is "all good?" Okay, then. I like knowing the what the rules are...unless of course, Beer/W Straw wants add an oblique reference to "pieces of sh!t".

    .......

    So tell me, Speedfreek. Who runs the circus here? YOU, or "BwS"?
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    Quote Originally Posted by Gerry
    So tell me, Speedfreek. Who runs the circus here? YOU, or "BwS"?
    Speaking of oblique reference, yet another insults from you.

    Speedfreek will decide if it is a circus or not, by banning you and Farsight ... or not.
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    Quote Originally Posted by Farsight View Post
    That's got to be wrong. Think about the early universe. It was dense. It had a high energy density. A bit like a black hole. The coordinate speed is said to be zero at the event horizon. As for the creationism, I've had conversations with creationists. I've shown them the strata, the fossils, the radio-dating, and they dismiss everything. Nothing counts as evidence with those people. But get this: they are convictional because they are people, not because they are religious. And they aren't the only people like that.
    Exactly: some people have convictions about physics. Eg., they will say that the early universe is like a black hole without being able to understand either and without any good reason to compare the two.
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    Quote Originally Posted by Gerry Nightingale View Post
    In reply to Speedfreek, re: post #50 & #55.

    So....this is "all good?" Okay, then. I like knowing the what the rules are...unless of course, Beer/W Straw wants add an oblique reference to "pieces of sh!t".

    .......

    So tell me, Speedfreek. Who runs the circus here? YOU, or "BwS"?
    The mods run the show. It is up to us to decide who is being more disruptive - the people peddling bad science or the people that get angered when they see it for what it is.

    Or the trolls, for that matter.
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    Gerry, you wanted to kill me and claim you were a victim...
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    Quote Originally Posted by Farsight View Post
    The coordinate speed is the speed. The proper speed is the locally measured speed, which is constant by definition, because of the tautology.
    You say because of the tautology. So the speed of light is only constant locally, because of a tautology. That "in reality", our seconds are either longer or shorter than the "coordinate" seconds, but, because of a tautology, we incorrectly assume them to be the same size. AND SO DO ALL OTHER PROCESSES IN THE UNIVERSE.

    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by SpeedFreek
    Of course, from the frame of the lower clock, the upper clock goes faster.
    And from the frame of the upper clock.
    From the frame of the upper clock, the lower clock goes slower. All clocks carry proper time, so the upper clock does not assume it is going fast, it assumes the lower clock is going slow. Because of that universal tautology, you know, the one where all physical processes work according to local proper time, rather than assuming that coordinate time is proper time.

    If we assume that coordinate time is proper time it would mean that lots of different observers in different frames of reference would all ascribe a different duration for the same process, which would be most confusing, would it not?

    A: "From my low gravitational potential, that process that occurred at a higher gravitational potential took only half the amount of seconds that the same process takes down here. The time that process took is the real time that it took. That process takes 10 seconds down here, but only 5 up there!"
    B: "Well from my very high gravitational potential, that process occurred at a lower gravitational potential and it took twice the amount of seconds that the same process takes up here. The time that process took is the real time that it took. That process takes 10 seconds up here too, but it took 20 down there!"
    A: "Your seconds are wrong. From down here I measured that process to take 5 seconds where it occurred, halfway between us, and only 2.5 seconds up where you are"
    B: "No, your seconds are wrong. From up here here I measured that process to take 20 seconds where it occurred, halfway between us, and 40 seconds where you are!"
    A: "Well, I know for sure that the process takes 10 seconds, here."
    B: "And I know for sure that the process also take 10 seconds, here.
    A: "No, it takes 2.5 seconds up there, but your seconds are shorter, so you only think it takes 10 seconds"
    B: "You have it wrong, my friend. That process takes 40 seconds where you are, but your seconds are longer, so you only think it takes 10 seconds".
    A: "Yours aren't real seconds, mine are!"
    B: "Rubbish! Mine are the real seconds!"
    Fundamental universal process: "Ummmmm, guys, stop arguing!! I always take 10 seconds, wherever I am! Time is proper time wherever I am! I am not the product of a tautology!!
    A + B: "Shut up! What do you know?!"
    Fundamental universal process: "No listen, it's true! It takes light the same amount of time to travel a metre, wherever it is!"
    A: "Well light travels at c in a vacuum down here."
    B: "And light travels at c in a vacuum up here too. But you are mistaken - it travels a little slower than c down there."
    A: "No it doesn't, I just measured it!"
    B: "But your seconds are wrong!"
    A: "No, your seconds are wrong!"
    Fundamental universal process: "*Sigh*"

    Quote Originally Posted by Farsight View Post
    All observers will agree that clocks go slower when they're lower. GR time dilation isn't symmetrical like SR time dilation.
    I didn't say it was symmetrical. I said from the frame of the lower clock, the upper clock goes faster. You quoted me.


    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by SpeedFreek
    {talk of Rindler horizons where the coordinate speed of light is zero}
    Yes, we know about this. But when we look at the fast-moving observer, we don't see a dark thing following him. We don't see light grind to a halt because he's moving fast through space.
    We don't, but he does, and that is exactly my point. A coordinate speed is the reality only from the frame of the observer in the frame that is measuring coordinate speed. It allows an observer to extend the laws of physics that work locally into places that are remote. It is not the reality for an observer at the actual coordinates in question. It is not what the universe is actually doing at that remote location, to anyone at that remote location, it is only what the universe is doing at that remote location, relative to you. It just allows one to translate our view of the laws of physics that are working over there, to over here, but it doesn't reflect reality for anyone who is actually over there, it just allows us to reconcile reality over there with reality over here.

    Therefore coordinate time is NOT about shorter or longer seconds in the way you keep saying. It is not that the coordinate speed is the actual, real speed of the object in question, to the object in question. It is only the real speed of the object to you. This is why we have to differentiate between proper and coordinate speed, and why coordinate speed is not just speed as you keep saying. This is why the speed of light "varying with position" is not a reference to a variable speed of light in the sense you seem to mean.

    If one observer near a black hole measures an observer falling into the black hole to be time-dilated asymptotically towards infinity as they approach the event horizon, it does not mean the star is actually frozen when you get there.

    Quote Originally Posted by Farsight View Post
    No. But like I said, for GR time dilation everybody agrees that the lower clock goes slower.
    No, everyone agrees on the difference between the clock rates, but the owner of the lower clock does not agree that their clock is going any slower than it was when they used to be higher. The owner of the lower clock agrees that the upper clock goes faster.

    Quote Originally Posted by Farsight View Post
    It isn't just some coordinate effect.
    See above. In the case of a black hole it is definitely a coordinate effect. The star isn't "frozen" when you get there. Atoms still "vibrate" at the same rate they ever did.

    Quote Originally Posted by Farsight View Post
    A negative speed is not a real speed. That's a distraction.
    No, it is a good illustration of how coordinate speeds are meaningful only to the person measuring them, but not at the actual remote place you are measuring them at. Anyone measuring that SAME light in its locale will measure the proper speed as c. Because of that universal "tautology" that everything in the universe adheres to.
    Last edited by SpeedFreek; 09-08-2014 at 01:03 AM.
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    Quote Originally Posted by Beer w/Straw View Post
    Gerry, you wanted to kill me and claim you were a victim...
    Indeed. And that is one of the reasons I stepped in and said no more of these threats and abuse.
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    Quote Originally Posted by Farsight View Post
    You said what you said, I referred to the post here. I'm not lying. You said this:

    "In a sense, this was done in 1905, when Einstein developed special relativity. This constancy of the speed of light is a postulate of the theory, so it is "shown" through the effectiveness and practicality of the theory. The same is true for general relativity, developed in 1915, which holds that the speed of light is constant at any infinitesimal region of a coordinate system."

    I haven't lied, and it's you who is personally attacking me, again.
    He is claiming you are wilfully misrepresenting his views. A lot of people claim you "cherry pick".

    Let me show you the implications of cherry picking.

    If "the speed of light is constant at any infinitesimal region of a coordinate system" then there is no region in a coordinate system where the speed of light is not constant. Take any infinitesimally small region and you will find the speed of light to be constant there. That's any infinitesimally small region. Is there any singular position in that coordinate system where the speed of light is not constant? How many infinitesimally small regions are there in a coordinate system? Is there any place in that coordinate system where there isn't an infinitesimally small region where the speed of light is c?

    Can light have two different speeds at the same place?
    Last edited by SpeedFreek; 09-08-2014 at 01:50 AM.
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    Quote Originally Posted by Farsight View Post
    The coordinate speed is the speed.
    Show us how to measure it *in general*. Do not use a single GR solution, do not make your solution dependent on a single set of coordinates, and do not make it involve a single set of observers.

    But what you don't know is that Einstein called it the speed of light.
    Scriptural percussion. Why are Einstein's statements so important? Was Einstein an inspired prophet of revealed truth?

    Quote Originally Posted by Farsight View Post
    No, your cherry-picking claim is fallacious, because I'm referring to hard scientific evidence along with multiple Einstein quotes and to Shapiro, Wright, Koks, Stenger, Magueijo, Moffat, and so on.
    More scriptural percussion.

    Quote Originally Posted by Farsight View Post
    The definition only clarified the tautology. Or should have done. The tautology applied to previous definitions of the metre because light and matter are of the "same essence". See the Wikipedia gravitational time dilation article and note this:

    "The speed of light in a locale is always equal to c according to the observer who is there. The stationary observer's perspective corresponds to the local proper time. Every infinitesimal region of space time may have its own proper time that corresponds to the gravitational time dilation there, where electromagnetic radiation and matter may be equally affected, since they are made of the same essence [5] (as shown in many tests involving the famous equation E=mc)."
    Wikipedia-thumping.

    Wikipedia is a good general reference, but I would not call it revealed truth. It is crowdsourced, and that makes its quality rather uneven.

    Quote Originally Posted by Farsight View Post
    It's very simple, you remember that clocks don't literally measure the flow of time,
    Who claims that clocks do that?
    Quote all you like, spacetime is still static. It isn't what space is.
    That's conflating looking from outside with looking from inside. We are on the inside, not the outside, and that's why we perceive changes with time.

    Nobody doubts gravitational potential.
    There is a well-defined scalar gravitational potential in the Newtonian limit, but not in GR.

    They aren't scripture quotes. Einstein said what he said:
    Again, what difference is that supposed to make?

    Quote Originally Posted by Farsight View Post
    I'm not some "my theory" guy.
    That's just too bad.
    I'm telling you what Einstein said.
    Again, Einstein's writings as sacred scripture.

    Can you show me those two different reference frames? No. There aren't two actual reference frames in the room you're in separated by 30cm. There is no multiplicity of reference frames 1mm apart, or 1 nanometre apart. They do not exist. They are abstract things.
    Nobody has ever seen a coordinate axis, either. Does that make analytic geometry worthless?

    Quote Originally Posted by Farsight View Post
    A clock just accumulates some kind of regular cyclical motion of cogs or a crystal or something else and gives you a cumulative display that we call the time. It doesn't actually measure the flow of time.
    A clock's actions are a *function* of time. I don't see how that is supposed to be so difficult to understand.
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    In reply to SpeedFreek, re: your #87.

    "INDEED"?!?! I NEVER said "I am going to kill" ANYONE! This is a deliberate distortion and re-edit of I post that I did right. YOU are allowing BwS to perpetuate a deliberate, intentional LIE

    and distortion of what I DID write...and you have just allowed AGAIN!!! What's up w/that??? You just don't like what I write, so you approve of a deliberate intentional LIE as long it

    pertains to me??? PROVE I WROTE "I am going to kill" anyone, anywhere, at anytime on this site or anywhere else! YOU CANNOT, because I NEVER WROTE IT!!!

    ......
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    Quote Originally Posted by Gerry Nightingale View Post
    In reply to SpeedFreek, re: your #87.

    "INDEED"?!?! I NEVER said "I am going to kill" ANYONE! This is a deliberate distortion and re-edit of I post that I did right. YOU are allowing BwS to perpetuate a deliberate, intentional LIE

    and distortion of what I DID write...and you have just allowed AGAIN!!! What's up w/that??? You just don't like what I write, so you approve of a deliberate intentional LIE as long it

    pertains to me??? PROVE I WROTE "I am going to kill" anyone, anywhere, at anytime on this site or anywhere else! YOU CANNOT, because I NEVER WROTE IT!!!

    ......

    If someone claimed that Gerry said he was going to kill someone and it turns out to be wrong then that is highly unethical. If that's the case I'll be boycotting the forum for a few days for false claims on Gerry.

    If that's a falsehood Gerry then please know that I've got your back pal. Alrighty?
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    In reply to Physicist, re: your #92 reply.

    Many Thanks for #92!

    I absolutely did NOT write a "death threat" against anyone, at anytime, anywhere.

    "BwS" continuously re-writes "posts" to say what "he thinks they mean" and this is outright malicious LIE on the part of "BwS" because he doesn't care for my writing of my "opinions" on

    this site! Did not "Speedfreak" just post in the last three days to CEASE WRITING PERSONAL ACCUSATIONS!!! And "BwS" just did it AGAIN without ONE WORD OF RECRIMINATION pertaining

    to "BwS" or "Boing" who jumped in w/ his "two cents worth of opinion" in agreement!!!

    And SpeedFreek says NOTHING right here on the this thread concerning "BwS"!!! What the hell type of "moderation" is this!!! He just allowed the same malicious accusation to BE POSTED

    AGAIN!!! In essence...this is approval of completely fabricated DISTORTION of what I actually wrote in a post. A LIE.

    ......

    I wrote a post because of continual harassment from "BwS" to invite him to "show up at my house and call me a retard again to my face, and I will show you just what "matter in motion"

    can do for real". I gave my REAL address, my P.O. #, and my cell #.

    "BwS" writes back "so you want to punch me in the face?" and I wrote "I don't fight fair, I would likely make a single fist to the throat, which would likely be fatal" and NOW HE responds

    that I basically published a "death threat" against him!!! What utter bullshit!!! And he keeps re-posting the same accusation, like right here on this thread!

    ......
    In what manner is an imagined confrontation AT MY HOME construed to be an actual "death threat?" Where do I say "I'm looking for you...I'm on the hunt for you...I'll find you". This is

    what "BwS" is implying and it is A COMPLETELY FABRICATED LIE on his part! I never wrote such completely utter drivel as an "empty threat" or a "real intention".

    HE IS A LIAR and backtracking the threads will PROVE IT.

    (I am really pissed-off here! It seems anyone who writes anything that deviates from "mainstream" is a "heretic" and should be despised, and "gotten rid of" by any means necessary, such

    as using a troll to taunt someone until they have enough, respond...and then are "warned" NOT TO FIGHT BACK!!! Tell me how I'm wrong w/this assessment, Physicist?)


    (Thanks for your words of support)
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    On Barry Setterfield's claim that the speed of light was infinite 6,000 years ago as proof of Biblical creationism.
    Quote Originally Posted by Farsight View Post
    That's got to be wrong. Think about the early universe. It was dense. It had a high energy density. A bit like a black hole. The coordinate speed is said to be zero at the event horizon. As for the creationism, I've had conversations with creationists. I've shown them the strata, the fossils, the radio-dating, and they dismiss everything. Nothing counts as evidence with those people. But get this: they are convictional because they are people, not because they are religious. And they aren't the only people like that.
    Farsight! Creationism is still creationism whether it's 6,000 years or 13,500,000,000 years - it is a matter only of degree not of kind!

    Einstein & the Bible-bashers are much closer than most might think, even though they like to consider only the former 'scientific'.

    The whole hassle you have created on this thread Farsight stems ONLY from your believing SR & GR (i.e. the supposed slowing of time in an increased gravitational field)! If you would abandon that nonsense, all the confusion would not arise in the first place. You only provide opportunities for those like BWS and Boing-boing to have a nervous breakdown or sound off piously about SR-based nonsense.

    If you would go back to basics and tease out the origin of SR you would find things are very different to what creationists would like you to think - and remember, you too are still caught up in creationism since you think in Big Bang terms, as I highlight above.

    TFOLZO
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    Quote Originally Posted by Physicist View Post
    If someone claimed that Gerry said he was going to kill someone and it turns out to be wrong then that is highly unethical. If that's the case I'll be boycotting the forum for a few days for false claims on Gerry.

    If that's a falsehood Gerry then please know that I've got your back pal. Alrighty?
    People can choose their words carefully...

    How 'bout this one: Gerry proclaiming I'm perpetuating a lie is a lie itself..

    He wants to be seen as a victim. so get his back for him.
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    Quote Originally Posted by TFOLZO
    The whole hassle you have created on this thread Farsight stems ONLY from your believing SR & GR (i.e. the supposed slowing of time in an increased gravitational field)! If you would abandon that nonsense, all the confusion would not arise in the first place.
    Let me get this straight. Are you claiming that gravitational time dilation is nonsense? If so then what led you to such a belief?
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    Of course GR (& gravitational time dilation) is nonsense!
    Quote Originally Posted by Physicist View Post
    Let me get this straight. Are you claiming that gravitational time dilation is nonsense? If so then what led you to such a belief?
    For starters it depends on SR - this is because in calculating the perihelion shift of Mercury SR is required to deal with Mercury's velocity, supposedly correcting the value by about 6 arcseconds/century, hence it is vital in Einstein's claims for GR (read Clifford Will's Was Einstein Right for the details).

    SR is BS as I demonstrate here on various threads - muon decay, Einstein's misrepresentation of the Fizeau experiment, the Doppler Ensemble Theory etc.

    The logical paradoxes of SR cannot be resolved without creating more logical paradoxes. 'Resolving' them through Minkowski Muddlegrams obscures the implication that you are creating parallel & daughter universes to "accommodate" the reciprocal TD&LC!

    If you want to argue the toss from Einstein's original article (OEMBS) or his Relativity then go ahead - or the Hafele-Keating experiments if you prefer. In this way we'll see how he & his cronies misrepresent physical situations in order to insert his own BS thinking - since Einstein is a true genius at philosophy!

    TFOLZO
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  98. #98  
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    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by KJW View Post
    And yet you did not answer the question I asked. Then you continued with more of not answering my question.
    I've answered all your questions. If you think I haven't or if you think I haven't answered it/them satisfactorily, please restate as necessary.
    How can 299792458 ms1 be different to 299792458 ms1 or 1 s be different to 1 s? Note that I asked how, not why? So I do not want any mention of gravitational time dilation. It is my claim that any difference is in your mind and not in any way tangible. Answering my question means presenting the difference in a tangible form.

    Also, you avoided giving a satisfactory reply to this:

    Quote Originally Posted by KJW View Post
    You didn't answer the question "by how much?" or give any quantification of the difference.
    Instead, you said:

    Quote Originally Posted by Farsight View Post
    You know how much. You know how gravitational time dilation affects clocks...
    The point of me asking the question is to give you the opportunity to demonstrate that you know the answer. At this point in the discussion, you've given me nothing to suggest that the differences in the speed of light or of the second are anything more than a figment of your imagination.


    Quote Originally Posted by Farsight View Post
    We all know what somebody means when they say the clock is slow.
    Apparently not. I take it to mean that the clock is faulty. But that's not the case for a clock at different locations.


    Quote Originally Posted by Farsight View Post
    I haven't said anything at all that violates the principle of GR.
    You said the clocks tick at different rates at different locations. However, I did consider that a variation of clock rates with respect to change in gravitational potential may not be a violation of the symmetry of the laws of physics. But that would require the mechanism of the clock to be sensitive to the gravitational potential, which given that there is no dependence on the particular type of clock, is unlikely.


    Quote Originally Posted by Farsight View Post
    Look, here's the Wikipedia time dilation article saying what I said:

    "The general theory of relativity describes how, for both observers, the clock that is closer to the gravitational mass, i.e. deeper in its "gravity well", appears to go more slowly than the clock that is more distant from the mass".
    The article says "appears to go more slowly", whereas you are claiming that it really goes more slowly.


    Quote Originally Posted by Farsight View Post
    So "a clock ticks less time" doesn't relate too well with the empirical evidence.
    That is precisely what the empirical evidence says, nothing else.


    Quote Originally Posted by Farsight View Post
    To get the right interpretation, you have to look hard at what a clock actually does.
    And herein lies the problem. Instead of looking at measurement at face value without interpretation, you impose your own interpretation onto the measurement and in doing so distort what the measurement is saying.
    A tensor equation that is valid in any coordinate system is valid in every coordinate system.
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    I think this forum is going to be a little quieter for a while. I will be temporarily suspending some members (it is up to them if they come back, or not), and permanently banning others, like Gerry, and TFOLZO. Other actions will be continuing, after further consultation between the moderators. I should have done this earlier and for that I apologise to the people remaining here. I had the stupid idea that sensible people could find a way to communicate with each other without the drama. I was wrong about part of that.

    Normal service will hopefully resume soon. Carry on.
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    Quote Originally Posted by Farsight View Post
    I've answered all your questions. If you think I haven't or if you think I haven't answered it/them satisfactorily, please restate as necessary...
    Although you were addressing KJW specifically, I feel that you have not answered any of my questions satisfactorily. I'll limit this particular missive to a single, basic issue:

    Forget about 299792458m/s for the moment, and just call it, say, "2". You are acknowledging that 2=2. At the same time, you are claiming that this 2 over here is not the same as that 2 over there. As a logical pair of statements, these fail. Once you acknowledge the first statement, the second cannot follow. There are no degrees of freedom in "2" that permit one 2 to differ from some other 2. Two is just...two. All the other verbiage about gravitational time dilation and the current price of Norwegian beaver cheese is simply irrelevant.
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