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Thread: The Varying Speed of Light

  1. #201  
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    Quote Originally Posted by x0x View Post
    Given the enormities that you have posted so far, I take your above post as meaningless trolling.
    I can do the calculation for you if you want.
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    Quote Originally Posted by PhysBang View Post
    I am still waiting for a description of how light moves through space.
    Like any wave moves through anything. Like an ocean wave moves through the sea, like a seismic wave moves through the ground. In mechanics a shear wave travels at a speed determined by the stiffness and density of the medium: v = √(G/ρ) where G is the shear modulus of elasticity and ρ is the density. In electrodynamics the expression is somewhat similar: c = √(1/ε0μ0) where ε0 is vacuum permittivity and μ0 is vacuum permeability.

    These are said to be constant like c, but they're not. If they were the NIST optical clocks at different elevations would stay synchronised, light wouldn't curve in a gravitational field, and your pencil wouldn't fall down. Note that vacuum impedance is Z0 = √(μ00) and that impedance is like resistance, but for alternating current rather than direct current. You might think so what? to which I would reply a light wave is alternating displacement current, see taming light at the nanoscale. This is one of those simple little things that somehow goes unnoticed. Here's a couple of depictions. On the left is alternating current, on the right is a light wave:



    This points to the underlying electromagnetic nature of gravity. When you have charged particles attracting one another, the raw electromagnetic force is immensely powerful. When you contrive a line of electrons moving up a wire made of positive ions, the attraction between two wires is modest. The force you see is a mere "trace" because the electromagnetic fields don't quite cancel. Then when you stop the electrons, the attraction between two wires is even more modest. Again the force you see is a mere trace because the electromagnetic fields don't quite cancel, but we don't call it magnetism.

    I should point out that the orthogonal electric and magnetic waves in the light-wave picture above is misleading. So is the myth that a light wave propagates because the "electric" wave induces a "magnetic" wave which induces an "electric" wave and so on. And that therefore light doesn't need a medium. That's cargo-cult nonsense. It's an electromagnetic wave, not an electric wave and a magnetic wave. And I should also mention that potential is more fundamental than field and field is the derivative of potential, so you could say it's a pulse rather than a wave. See How Long Is a Photon? by Drozdov and Stahlhofen.


    btr: I can only apologise that there are people like x0x kicking around in physics, and that they do not attract the moderation that would make them remain civil. But given the situation that we have, can I ask that you "do not feed the troll".
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  3. #203  
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    Quote Originally Posted by Farsight
    But given the situation that we have, can I ask that you "do not feed the troll".
    talking about yourself again, Duffield?
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    Quote Originally Posted by Farsight View Post
    Like any wave moves through anything. Like an ocean wave moves through the sea,

    <more irrelevant text removed>
    Farsight, you are arguing for a time-free, motion-only, one-reference-frame-to-rule-them-all, one-absolute-space physics.

    You provide citations to articles that rely on assumptions that directly contradict your hypotheses, as vague as they are.

    You need to be able to tell us how one can describe the motion of light in space in a way that does not require some sort of spacetime. If you can't do this, then, at best, you need to rethink your entire project.
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    Quote Originally Posted by PhysBang View Post
    Farsight, you are arguing for a time-free, motion-only, one-reference-frame-to-rule-them-all, one-absolute-space physics. You provide citations to articles that rely on assumptions that directly contradict your hypotheses, as vague as they are.
    Methinks you need to read the OP, Physbang. It was Einstein who said the speed of light varies with position. And you ought to read the Baez article too:

    "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".

    Quote Originally Posted by PhysBang
    You need to be able to tell us how one can describe the motion of light in space in a way that does not require some sort of spacetime. If you can't do this, then, at best, you need to rethink your entire project.
    Motion is what we call it when something gradually changes position. Light moves through space. Spacetime is a static mathematical abstract thing which we use to model the equations of motion. But note that there is no motion through spacetime. You can draw worldlines in it, but it's a static "block universe" thing that depicts space at all times. Try not to confuse space with spacetime and you'll be OK.
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    So it is correct to say that you think "time" is an illusion and doesn't actually exist?
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    Quote Originally Posted by Farsight View Post
    Methinks you need to read the OP, Physbang.

    <More Einstein Theology snipped>
    I did read the OP: that's where you, in order to explain what you meant, provided citations to papers that use a scalar change in the speed of light of a vastly different kind than Einstein used.

    The OP is where you claim that there is only one standard for time: motion.

    So it would not be a lie when you then later deny these things when asked to provide the details: it is a mistake that doesn't stain your character.


    Motion is what we call it when something gradually changes position.
    What is a change in position?

    So far, you have done your damnedest not only to not do physics, but to not even explain what you mean in your interpretation about what a motion is.
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    MODERATOR NOTE : I see a growing trend ( both on this and the other threads dealing with this topic ) of people attacking the person rather than the argument. This stops here. We are all on this forum for the sole purpose of having a meaningful discussion - this does not mean that we will always agree with everyone else, nor does it mean that we will always be in a position to convince others of our point of view. That's life, deal with it ! If you have valid arguments, go ahead and discuss them; if you think you see errors in someone else's reasoning, point them out and explain why you think they are erroneous. If you have nothing meaningful to contribute, just stay quiet and stop participating until such time when you feel you are ready to re-enter the conversation. This is just an Internet forum, no more. Do not attack the person just because they don't share your point of view or just because you are unable to sway their opinions, that is not the purpose of this whole thing. It's about arguments, not egos - there are no winners and losers here, just participants, and we learn not from putting others down or lifting them up, but by the arguments that are being brought forward.

    I note that more or less everyone here has reported everyone else, but I have thus far chosen not to intervene. Take this post of mine as a warning - if the ego attacks and sniping continue, going forward I will start to take action against the participants concerned. Keep these discussions clean, and talk like mature adults do please.

    Thank you.
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    What I do not understand is when and how did this forum become a platform for Farsight? Isn't this forum supposed to be a science forum? By the looks of it, it certainly isn't. I can trace most of the attacks to two things:

    -peoples growing frustration with Farsight's anti-science posts
    -his petulant , insolent answers when challenged
    So, my question is, why is this allowed to continue? What is the scientific benefit? No one has ever managed to debunk his statements, he just keeps pouring more of the same. There are currently no less than 6 (the total is 28!) anti-mainstream threads started by Farsight in the main forum. Why aren't they in the "Personal Theories" or "Trash Can" forums, where they truly belong?
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    Quote Originally Posted by Beer w/Straw View Post
    So it is correct to say that you think "time" is an illusion and doesn't actually exist?
    No. I say time exists like heat exists.

    Heat is an emergent property. There's no such thing as heat at the subatomic level. A "hot" electron is a fast-moving electron. The temperature of an ideal gas is akin to an average measure of the kinetic energy of the molecules, or more simply an average measure of motion. So heat is an emergent property of motion, but it's real. It exists. Heat will burn you. Heat will kill you. Time is another emergent property of motion, but it's a cumulative measure rather than an average measure. And a hundred years will kill you just a surely as a hundred degrees Centrigrade.

    See time travel is a fantasy for more. I mentioned the book A World Without Time: The Forgotten Legacy of Godel and Einstein. The title might suggest that time does not exist, but it's more like time does not exist as we ordinarily understand it.
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    OK, so please show us how to describe a physical scenario, any physical scenario, without time.
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    Huh? I said time exists like heat exists. I didn't say time does not exist. But I will reiterate that a clock doesn't actually measure the literal flow of time like some kind of cosmic gas meter. It features some kind of regular cyclical motion that is effectively counted and displayed as some kind of cumulative result that we call "the time".
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    Quote Originally Posted by Farsight View Post
    Huh? I said time exists like heat exists. I didn't say time does not exist. But I will reiterate that a clock doesn't actually measure the literal flow of time like some kind of cosmic gas meter. It features some kind of regular cyclical motion that is effectively counted and displayed as some kind of cumulative result that we call "the time".
    People who say, with some reasonable support, that "heat exists as an emergent property", have a means of describing physical systems that they can point to and explain what they mean.

    If you are to do so with "time", you need to show us how to describe a physical system without time, only with motion, and show us how to get time emerging from your description.

    Unless you want us to merely dogmatically assume your metaphysics.
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    As to heat as an emergent property, it comes out of something called statistical mechanics. That's a well-defined field with lots of successes since its emergence in the mid to late 19th cy. Unfortunately, Farsight's theory that time is an emergent property does not even come close. As far as I've been able to discover, there is no mathematical formulation of it, as there is for stat mech, and no claimed support other than childishly-interpreted observations and mined quotes treated as Holy Writ.
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    So, my question is, why is this allowed to continue? What is the scientific benefit?
    The benefit is in giving people the opportunity to show why Farsight's arguments are not in accord with current scientific understanding. It is about the points being put forward, not about who is wrong and who is right; people here are not novices, we already know what is part of real-world physics and what isn't, so it isn't the purpose of these discussions to establish that. I am not expecting anyone here to take on board Farsight's views, nor am I expecting Farsight to abandon his opinions on the matter. Science is not made here, nor will people's convictions and understandings be changed. I am merely curious as to what arguments both sides can bring forward, and yes, there is benefit in that.

    I will let this run for a while longer; I am perfectly aware that some aspects of the discussions are starting to become repetitive, but I believe that some good points are still to be made. I will terminate these threads once I feel that nothing new is being contributed, but we are not quite there yet.

    The above answers your question, and the matter will not be discussed further here or on any other thread. I understand that some of you might get frustrated, but you are mature adults - if you don't enjoy participating, just stop. The choice is yours. If you feel you can't stop because you need to have the last word over Farsight, then you have to seriously consider your motives for being here in the first place.
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    Quote Originally Posted by lpetrich View Post
    As to heat as an emergent property, it comes out of something called statistical mechanics. That's a well-defined field with lots of successes since its emergence in the mid to late 19th cy. Unfortunately, Farsight's theory that time is an emergent property does not even come close.
    It isn't my theory. The "time is change" idea goes back as far as the ancient Greeks, to Heraclitus I think it was. Then it was resurrected as Presentism in 1908, which is what features in A World without Time: The Forgotten Legacy of Godel and Einstein. Something else that isn't my theory is the varying speed of light, see arXiv. And of course the Einstein quotes in the OP.

    All: lpetrich knows all this, I've told him before. He tries to pretend this is some "my-theory" and throws in phrases like "Holy Writ" for his own reasons. Please do your own research.
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    Quote Originally Posted by Markus Hanke View Post
    The benefit is in giving people the opportunity to show why Farsight's arguments are not in accord with current scientific understanding...
    I like to think that what we have here is a thought-provoking and challenging thread. One which is an example of the debate and dissemination via which science advances. Again see the Baez article where you can read this:

    "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."

    This is not in accord with what you think scientific understanding is, but it's written by a relativist called Don Koks who is the editor of the Usenet FAQ webpages. Yes I exchanged some emails with him about some issues with the previous version written by Phil "viXra" Gibbs. But the varying speed of light is not something I've made up. Einstein really did refer to it repeatedly. He really did say a curvature of light can only occur when the speed of light varies with position. And more importantly the evidence for it is surely patent, because there is no literal time flowing in an optical clock. So when nobody can show why I'm wrong, you should consider the very real possibility that I'm right, and keep the thread open. In time you might make it a sticky, because you finally appreciate that getting you to understand all this is like shifting a tooth. By the by, what I think would be interesting is to go through some of your "primer" threads talking about why the maths applies and the underlying reality it relates to.
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    Quote Originally Posted by Farsight View Post
    It isn't my theory. The "time is change" idea goes back as far as the ancient Greeks, to Heraclitus I think it was. Then it was resurrected as Presentism in 1908, which is what features in A World without Time: The Forgotten Legacy of Godel and Einstein. Something else that isn't my theory is the varying speed of light, see arXiv. And of course the Einstein quotes in the OP.

    All: lpetrich knows all this, I've told him before. He tries to pretend this is some "my-theory" and throws in phrases like "Holy Writ" for his own reasons. Please do your own research.
    You cannot dodge the fact that you have your own theory by pretending you are merely saying things that others have said. You have your own theory: that you pretend that it is the theory of others and that you have apparently no reasons to support your own theory does you no favors.

    So again I ask: please show us how to describe a physical system without time, either as the ancient Greeks did it or as someone else did it, in your interpretation.
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    I've answered this question previously, more than once. You still have a t in your equations to represent time, you merely recognise that time is a measure of change or motion rather than something that flows or passes. You recognise that a clock clocks up some kind of regular cyclic motion rather than "the flow of time", and that when a clock goes slower it's because that motion is going slower. This is the empirical view. If you'd rather believe that a clock is like some kind of gas meter with time flowing through it, that's up to you.
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    Quote Originally Posted by Markus Hanke
    The above answers your question, and the matter will not be discussed further here or on any other thread. I understand that some of you might get frustrated, but you are mature adults - if you don't enjoy participating, just stop. The choice is yours. If you feel you can't stop because you need to have the last word over Farsight, then you have to seriously consider your motives for being here in the first place.
    Why are Farsight's threads in the main forum? Why aren't they in "Personal Theories" (or Trash)?
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    PhysBang - Do you disagree with Farsight's assertion that "time is change"? I myself have always taken time to mean this and know that it does indeed go back to at least Aristotle. I have a book called The Philosophy of Time Ė A collection of Essays (1967). The introduction reads
    The first serious attempt to analyze the concept of time occurs in Aristotleís Physics. He raises the question, ď[I]In what sense, if any, can time be said to exist?Ē For Aristotle, only individual substances, which are compounds of form and matter, be said to exist, every can be said to exist in an unqualified sense, everything else being attributes of these substances. Time is defined as ďnumber of movement in respect Ďbeforeí and Ďafter.í Motion is an attribute of a substance, and time in turn is an attribute of motion. Time is not motion, but a measure of motion.
    I find myself in nearly exact agreement with this statement about time. However I think of something existing when that thing that it refers to occurs in nature. For example; if something moves then there is a time associated with it. Since the motion has no substance to it I myself donít look at it as time not existing however but exists because the thing in nature which it refers to, i.e. motion, actually occurs.
    Last edited by Physicist; 07-16-2014 at 03:23 AM.
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    I have done quite a bit of thinking about time.

    I see that Farsight now admits that there is, in fact, no way to do away with time in physical descriptions. That's a good step forward.

    Now we need to understand how it can be that a clock runs slower and how we can determine which clock is flowing slower. If Farsight would just produce a description of a single physical system, we could begin.
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    In reply to AIP's this "thread".

    Is it unreasonable to consider "time" as an arbitrary, assigned function? Rather than an actual entity that must be regarded as "real?"

    ......

    Cheers to Jilan!
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    Quote Originally Posted by PhysBang View Post
    I have done quite a bit of thinking about time.

    I see that Farsight now admits that there is, in fact, no way to do away with time in physical descriptions. That's a good step forward.

    Now we need to understand how it can be that a clock runs slower and how we can determine which clock is flowing slower. If Farsight would just produce a description of a single physical system, we could begin.
    Just look inside a clock. A mechanical clock "clocks up" the regular cyclical motion of cogs and gears and show you a cumulative total that you call the time. A quartz clock clocks up the vibrations of a crystal. And so on. When the clock goes slower that motion goes slower. Even when its an optical clock, because electromagnetic radiation and matter may be equally affected, since they are made of the same essence.

    That's it. It's that simple. There is no time flowing inside a clock. A clock does not actually measure the flow of time. It features some kind of regular cyclical local motion. Learn that and the scales will fall from your eyes, and you will understand gravity like you've never understood it before.

    Quote Originally Posted by Gerry Nightingale View Post
    Is it unreasonable to consider "time" as an arbitrary, assigned function? Rather than an actual entity that must be regarded as "real?"
    It's reasonable. But you can get into difficulty with words like "real". Heat is real, heat will kill you. And a hundred years will kill you just as surely as a hundred degrees centigrade.
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    Quote Originally Posted by x0x View Post
    Why are Farsight's threads in the main forum? Why aren't they in "Personal Theories" (or Trash)?
    Because this isn't my theory, it's just something you don't know about because you haven't been taught it. Like I said the "time is change" idea goes back to ancient Greece. Then we had Presentism in 1908, which is the opposite of Eternalism. When people think of spacetime and the block universe, they're thinking in terms of Eternalism. But Einstein rejected that in A World without Time: The Forgotten Legacy of Godel and Einstein.

    Something else that isn't my theory is the varying speed of light, see arXiv, the Einstein quotes, and the Baez website. I'm not some my-theory guy. Guys like that say "Einstein was wrong". Here it's lpetrich who's saying that. I'm just the guy who's got the heads up on scientific progress.
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    Quote Originally Posted by Farsight View Post
    Because this isn't my theory
    Boo hoo hoo hoo hoo.
    ... the Einstein quotes
    Book thumping. Farsight, this is science, not theology, and Einstein was not some inspired prophet.
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    Quote Originally Posted by Farsight View Post
    Just look inside a clock. A mechanical clock "clocks up" the regular cyclical motion of cogs and gears and show you a cumulative total that you call the time. A quartz clock clocks up the vibrations of a crystal. And so on. When the clock goes slower that motion goes slower. Even when its an optical clock, because electromagnetic radiation and matter may be equally affected, since they are made of the same essence.

    That's it. It's that simple. There is no time flowing inside a clock. A clock does not actually measure the flow of time. It features some kind of regular cyclical local motion. Learn that and the scales will fall from your eyes, and you will understand gravity like you've never understood it before.
    Congratulations on once again failing to do any physics. You are once again retreating from a reasonable position and hiding in fantasy. Until you are able to describe a physical system using physics, you are stuck in dogmatic metaphysics.
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    Quote Originally Posted by Farsight View Post
    Because this isn't my theory, it's just something you don't know about because you haven't been taught it. Like I said the "time is change" idea goes back to ancient Greece. Then we had Presentism in 1908, which is the opposite of Eternalism. When people think of spacetime and the block universe, they're thinking in terms of Eternalism. But Einstein rejected that in A World without Time: The Forgotten Legacy of Godel and Einstein.
    The sad thing is, if Farsight actually studied contemporary metaphysics (or it equivalent), he would know that there are lots of papers on presentism and how it, or a sufficiently modified version of it, is compatible with GR. Additionally, it seems well established that claims that SR or GR (with the standard use of "spacetime") alone imply a "block universe" theory of time are relying on fallacious reasoning.

    Something else that isn't my theory is the varying speed of light, see arXiv,
    That reference is simply insulting, since those papers are presenting an alternative to GR that operates differently from GR. So Farsight is now claiming that his theory is both faithful to GR and different from GR.

    It's the kind of response that we can accept from children, not from someone trying to discuss things seriously.

    I'm just the guy who's got the heads up on scientific progress.
    And yet you seemingly confuse what is and isn't your pet physics.
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    Quote Originally Posted by Farsight
    Because this isn't my theory, it's just something you don't know about because you haven't been taught it.
    Duffield,

    Everything you post is your, fringe theory.
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    Quote Originally Posted by PhysBang View Post
    The sad thing is, if Farsight actually studied contemporary metaphysics (or it equivalent), he would know that there are lots of papers on presentism and how it, or a sufficiently modified version of it, is compatible with GR.
    That's essentially what A World without Time: The Forgotten Legacy of Godel and Einstein is all about. So what's the problem?

    Quote Originally Posted by PhysBang
    Additionally, it seems well established that claims that SR or GR (with the standard use of "spacetime") alone imply a "block universe" theory of time are relying on fallacious reasoning.
    You should ask around about that, and do your own research. Start with Eternalism on Wikipedia where you can read this:

    "Many philosophers have argued that relativity implies eternalism.[3] Although he disagrees in a qualified sense, philosopher of science Dean Rickles notes that "the consensus among philosophers seems to be that special and general relativity are incompatible with presentism..."

    Quote Originally Posted by PhysBang View Post
    That reference is simply insulting, since those papers are presenting an alternative to GR that operates differently from GR.
    It isn't insulting in the least. Einstein said the speed of light varies with position, if other people do too it doesn't matter whether they're presenting alternatives to GR. The speed of light varies regardless.

    Quote Originally Posted by PhysBang
    It's the kind of response that we can accept from children, not from someone trying to discuss things seriously.
    Only you now accept the varying speed of light. Don't you?
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    Quote Originally Posted by Farsight View Post
    That's essentially what A World without Time: The Forgotten Legacy of Godel and Einstein is all about. So what's the problem?
    The problem is that you are shooting out a hodge-podge of claims without bothering to demonstrate that they are related to each other or to how physical systems behave.
    You should ask around about that, and do your own research. Start with Eternalism on Wikipedia where you can read this:

    "Many philosophers have argued that relativity implies eternalism.[3] Although he disagrees in a qualified sense, philosopher of science Dean Rickles notes that "the consensus among philosophers seems to be that special and general relativity are incompatible with presentism..."
    I've done the research and I'll trust the primary sources and the philosophers and physicist that I know over wikipedia.

    It isn't insulting in the least. Einstein said the speed of light varies with position, if other people do too it doesn't matter whether they're presenting alternatives to GR. The speed of light varies regardless.
    It may be that you have so little comprehension about anything that you do not realize how insulting you are. However, I will be charitable.

    You are claiming that GR uses a variable speed of light as its sole fundamental means of operation. Your evidence for this are papers that do not use GR. Do you see the problem?

    You probably do not see the problem. Regardless, until you demonstrate how one can use your interpretation, and your interpretation alone, to even describe a physical system, you are far from physics.
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    Well, looking for something historically accurate

    Einstein realized that the world described by Isaac Newton (left), in which one could add and subtract velocities, and that described by James Clerk Maxwell, in which the speed of light is constant, could not both be right.

    NOVA | The Theory Behind the Equation
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    Quote Originally Posted by PhysBang View Post
    The problem is that you are shooting out a hodge-podge of claims without bothering to demonstrate that they are related to each other or to how physical systems behave.
    There's nothing hodge-podge about the varying speed of light. And it isn't just something I've made up.

    Quote Originally Posted by PhysBang
    I've done the research and I'll trust the primary sources and the philosophers and physicist that I know over wikipedia.
    Let me put it another way then. Trust me above anybody else, because I'm here with the explanations and reference, I'm here to be challenged and to deal with anything you're dissatisfied with.

    Quote Originally Posted by PhysBang
    It may be that you have so little comprehension about anything that you do not realize how insulting you are. However, I will be charitable.
    You aren't charitable, you're insulting. I'm not.

    Quote Originally Posted by PhysBang
    You are claiming that GR uses a variable speed of light as its sole fundamental means of operation. Your evidence for this are papers that do not use GR. Do you see the problem?
    I'm not claiming that. I'm claiming that Einstein said the speed of light varies, and I'm claiming the patent evidence supports him.

    Quote Originally Posted by PhysBang
    You probably do not see the problem. Regardless, until you demonstrate how one can use your interpretation, and your interpretation alone...
    What part of the Baez article did you miss? Here it is 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."

    It isn't just my interpretation. Now is it?
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    Quote Originally Posted by Beer w/Straw View Post
    Well, looking for something historically accurate

    Einstein realized that the world described by Isaac Newton (left), in which one could add and subtract velocities, and that described by James Clerk Maxwell, in which the speed of light is constant, could not both be right.

    NOVA | The Theory Behind the Equation
    It's not a bad SR article. However like most accounts it doesn't explain why you always measure the speed of light to be the same. The answer is because of the wave nature of matter. Robert Close nails it in The Other Meaning of Special Relativity. Here's a fair-use excerpt:

    Quote Originally Posted by Robert Close
    Now we are in a position to appreciate what is special about light. Ordinarily we do not measure distances and times by propagating waves back and forth. Instead we use material clocks and rulers. The amazing thing about material clocks and rulers is that the resulting distance and time measurements transform with exactly the same Lorentz transformations as would be obtained if the measurements had been made by propagating light waves. In other words, matter behaves as if it consists of soliton waves which propagate at the speed of light. Let us take this as an alternative postulate for special relativity: matter consists of waves which propagate at the speed of light. This alternative postulate is simply the de Broglie wave hypothesis5 with the condition that the waves propagate at the speed of light. This physical picture suggests that matter and anti-matter can annihilate into photons and vice versa because photons and matter are simply different packets of the same type of wave. Our new hypothesis is also consistent with the Dirac equation for the electron, in which the velocity operator has eigenvalues of magnitude c. The mass term represents rotation of the propagation direction, which explains why the apparent speed is always less than the speed of light. The wave paths are like spirals (or cycloids) rather than straight lines...
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    OK, I don't know what you're throwing at me here.

    I don't know who Robert Close is, but I can stare at Maxwell's equations.

    I'll even be dumb enough to post a youtube video

    Doc Physics - Maxwell&#39;s Equations and the Speed of Light - YouTube
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    Farsight, you have no explanation. On order to explain something, your explanation must be about the thing explained. So far, you have refused to show us that what you say matches physics.
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    OK, so if the speed of light changes, the electric and/or permeability of free space would change. So why would this change? Is Space somehow denser near a large mass?
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    This is a wiki quote:

    The Shapiro time delay effect, or gravitational time delay effect, is one of the four classic solar system tests of general relativity. Radar signals passing near a massive object take slightly longer to travel to a target and longer to return than they would if the mass of the object were not present. The time delay is caused by the slowing of light as it moves through a change in gravitational potential. In an article entitled Fourth Test of General Relativity, Shapiro et al. wrote [1]

    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.


    Shapiro delay - Wikipedia, the free encyclopedia

    The speed, however, is not measured locally.
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    Quote Originally Posted by Beer w/Straw View Post
    The speed, however, is not measured locally.
    That's because the cause of the slowed light speed is the slowing of time in the region where the light passes. This, in tern, is a result of the difference between the gravitational potential between observer and light which cause clocks lower in the gravitational field to run slower.
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  40. #240  
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    Quote Originally Posted by Beer w/Straw View Post
    This is a wiki quote:

    The Shapiro time delay effect, or gravitational time delay effect, is one of the four classic solar system tests of general relativity. Radar signals passing near a massive object take slightly longer to travel to a target and longer to return than they would if the mass of the object were not present. The time delay is caused by the slowing of light as it moves through a change in gravitational potential. In an article entitled Fourth Test of General Relativity, Shapiro et al. wrote [1]

    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.


    Shapiro delay - Wikipedia, the free encyclopedia

    The speed, however, is not measured locally.
    I would say that there is no speed other than that measured locally, and that "The time delay is caused by the slowing of light as it moves through a change in gravitational potential." from the quote is nothing more than a simplification of a general relativistic effect that would be otherwise difficult to express to the novice. However, Farsight has turned this simplification into a some sort of deep revelation about physics, failing to realise that in the context of curved spacetime, it makes no real sense at all.
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    A tensor equation that is valid in any coordinate system is valid in every coordinate system.
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    Quote Originally Posted by KJW View Post
    I would say that there is no speed other than that measured locally, ....
    Why? How is that any different than saying that there is no other time other than that measured locally?

    In practice scientists don't follow a beam around the solar system with clocks are rods so in that sense its impractical to think of it that way.
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    Quote Originally Posted by Physicist View Post
    That's because the cause of the slowed light speed is the slowing of time in the region where the light passes. This, in tern, is a result of the difference between the gravitational potential between observer and light which cause clocks lower in the gravitational field to run slower.
    That sounds like the opposite of what Farsight always says.
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    In reply to AIP's this thread.

    "Light slows?" Really? Clocks also?

    I thought this was decided long ago...and verified every time an observation is made.

    "The slowing of Time?"

    (all of this is over my head!)
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    Quote Originally Posted by Jilan View Post
    OK, so if the speed of light changes, the electric and/or permeability of free space would change. So why would this change? Is Space somehow denser near a large mass?
    Kind of. It's like it's subject to an outward pressure. Einstein said the matter "conditions" the surrounding space altering its metrical properties. Here we go: Einstein: "Ether and Relativity"

    Quote Originally Posted by Einstein
    "...According to this theory the metrical qualities of the continuum of space-time differ in the environment of different points of space-time, and are partly conditioned by the matter existing outside of the territory under consideration. This space-time variability of the reciprocal relations of the standards of space and time, or, perhaps, the recognition of the fact that "empty space" in its physical relation is neither homogeneous nor isotropic, compelling us to describe its state by ten functions (the gravitation potentials gmn), has, I think, finally disposed of the view that space is physically empty. But therewith the conception of the ether has again acquired an intelligible content although this content differs widely from that of the ether of the mechanical undulatory theory of light. The ether of the general theory of relativity is a medium which is itself devoid of all mechanical and kinematical qualities, but helps to determine mechanical (and electromagnetic) events..."
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    Quote Originally Posted by Physicist View Post
    That's because the cause of the slowed light speed is the slowing of time in the region where the light passes.
    Actually Physicist, I don't agree with this. It might sound like nitpicking, but I think it's important: light just goes slower in that region. And because light and matter "are made of the same essence" everything goes slower in that region. So we say time goes slower. Even though we can't actually see time going anywhere.

    Quote Originally Posted by Physicist View Post
    This, in turn, is a result of the difference between the gravitational potential between observer and light which cause clocks lower in the gravitational field to run slower.
    Fair enough. And this is turn caused by a concentration of energy tied up as the matter of a planet, which "conditions" the surrounding space, the effect diminishing with distance.
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    Quote Originally Posted by KJW View Post
    I would say that there is no speed other than that measured locally
    Only two NIST optical clocks are right there in the room you're in, one 30cm lower than the other, and it goes slower because light goes slower when its lower. And PhysBang said this here:

    "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".

    So it isn't constant in a non-infinitesimal region. Even PhysBang admits it.

    Quote Originally Posted by KJW
    and that "The time delay is caused by the slowing of light as it moves through a change in gravitational potential." from the quote is nothing more than a simplification of a general relativistic effect that would be otherwise difficult to express to the novice.
    No! It's no simplification, that's how it is. That's why Einstein said a curvature of light can only occur when the speed of light varies with position. Light doesn't curve because spacetime is curved. It curves because the speed of light varies with position. Spacetime is a static abstract thing. Nothing moves in it.

    Quote Originally Posted by KJW
    However, Farsight has turned this simplification into a some sort of deep revelation about physics, failing to realise that in the context of curved spacetime, it makes no real sense at all.
    It makes perfect sense. That's why you can read 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".

    That's why Professor Ned Wright says this: "In a very real sense, the delay experienced by light passing a massive object is responsible for the deflection of the light". Spacetime curvature isn't. I'm sorry KJW, but what you've been taught is wrong.
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    Quote Originally Posted by Farsight View Post
    Kind of. It's like it's subject to an outward pressure. Einstein said the matter "conditions" the surrounding space altering its metrical properties. Here we go: Einstein: "Ether and Relativity"
    Why quote this outlying passage and not actually produce the relevant equations?

    Perhaps you could give us an example where you could show us how your interpretation actually plays a role in a physical scenario?
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  48. #248  
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    Quote Originally Posted by Farsight View Post
    Only two NIST optical clocks are right there in the room you're in, one 30cm lower than the other, and it goes slower because light goes slower when its lower. And PhysBang said this here:

    "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".

    So it isn't constant in a non-infinitesimal region. Even PhysBang admits it.
    OK, so clearly we have to identify this as a lie.

    I wrote, "In a sense, [the speed of light is absolute in all reference frames] 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."

    You know what, go ahead and ban me for pointing out how deceptive John Duffield is. Maybe he's just crazy. I will continue to point out his lying when I see it.

    It's really great when this forum supports someone clearly attributing the opposite of what another poster said.

    It's really great when this forum supports a guy who can't do the most basic of physics in polluting every single thread with his fantasy physics.


    No! It's no simplification, that's how it is. That's why Einstein said a curvature of light can only occur when the speed of light varies with position. Light doesn't curve because spacetime is curved. It curves because the speed of light varies with position. Spacetime is a static abstract thing. Nothing moves in it.
    And that, too, is a lie. Or a sign that Farsight is simply mentally ill.

    Why a lie? Because Farsight doesn't know how to actually use spacetime to do any physics, so when he makes pronouncements about it, he is presenting himself as someone who knows something about the relevant physics. Since he doesn't, he is attempting to deceive the readers of this thread and is arguing in bad faith.


    That's why Professor Ned Wright says this: "In a very real sense, the delay experienced by light passing a massive object is responsible for the deflection of the light". Spacetime curvature isn't. I'm sorry KJW, but what you've been taught is wrong.
    And this is a lie, because it implies that Ned Wright denies curvature, when curvature is the reason for time delay and Ned Wright knows this.

    Now it could be that Farsight has some sort of mental illness that keeps him from realizing what Ned Wright believes even though Wright is quite explicit in the contents of his beliefs on this subject. However, given his willingness to lie on other subjects, I feel confident that he is knowingly attempting to deceive.
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    Quote Originally Posted by Farsight View Post
    Einstein said the matter "conditions" the surrounding space altering its metrical properties.
    Argument by book-thumping again. Is Albert Einstein supposed to be a Prophet of Revealed Truth?
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    So it isn't constant in a non-infinitesimal region.
    It's not defined across an extended region where curvature plays a role, since there is no global notion of time across such a region. Time is a local phenomenon, and hence so is speed. The notion of "coordinate speed" is physically meaningless because it cannot tell us what happens locally at each point.
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    One might try defining the speed of light nonlocally by measuring its travel distance and time from point A to point B in this way. Measure distance with a spacelike geodesic from A to point C and time with a timelike geodesic from C to B, with the spacelike and timelike geodesics having orthogonal tangents at C. Or else use a timelike geodesic from A to C, then a spacelike geodesic orthogonal to it from C to B.

    But it is not difficult to show that the ratio of distance to time is a function of which point C that you select, given A and B. I once did it by considering the almost-flat case, where R*(distance or time)2 << 1.
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    But it is not difficult to show that the ratio of distance to time is a function of which point C that you select, given A and B.
    Yes, that is precisely what I mean when I say that speed is a local notion; attempting to define "global" speed in a curved space-time is meaningless, you can do it only at a given point.
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    In reply to PhysBang, re: your #248 post.

    Don't you think you're being little too harsh!? (yikes!...lying? in what manner is an opinion or interpretation a "lie?")

    Oy!...it's just a website that encourages discussions. Nothing is worth being "mean" over!
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  54. #254  
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    Quote Originally Posted by Physicist View Post
    Quote Originally Posted by KJW View Post
    I would say that there is no speed other than that measured locally, ....
    Why? How is that any different than saying that there is no other time other than that measured locally?
    I don't think it is any different to saying that there is no other time other than that measured locally. If I have a clock that ticks one second intervals, then it ticks one second intervals whether it is on the top floor or the bottom floor of a building. And a one second interval on the top floor is the same as a one second interval on the bottom floor (i.e. it is a one second interval). This does not conflict with gravitational redshift. Suppose pulses of light are sent from the bottom floor to the top floor each second as measured by the clock on the bottom floor. Then at the top floor the pulses will be slightly greater than one second apart as measured by the clock on the top floor. Quite simply, the interval between the pulses is one second at the bottom floor and slightly greater than one second at the top floor. There is no justification to claim that the intervals at the bottom and top floors should be equal in the sense that the top floor clock has measured the bottom floor interval to be slightly greater than one second. The interval between the pulses at a given location is quite simple the interval between the pulses measured by a clock at that location.
    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
    Quote Originally Posted by KJW View Post
    I would say that there is no speed other than that measured locally
    Only two NIST optical clocks are right there in the room you're in, one 30cm lower than the other
    Just because the two clocks are 30cm apart doesn't make them local to each other. Local means close enough that any differences are insignificant. A 30cm separation may be insignificant for many purposes, but it is not insignificant in this particular case.


    Quote Originally Posted by Farsight View Post
    the speed of light is constant at any infinitesimal region... So it isn't constant in a non-infinitesimal region
    This is a logical error.


    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by KJW
    and that "The time delay is caused by the slowing of light as it moves through a change in gravitational potential." from the quote is nothing more than a simplification of a general relativistic effect that would be otherwise difficult to express to the novice.
    No! It's no simplification, that's how it is.
    Really? In any of the quotes that you've read, did it say that it wasn't a simplification and that it's how it is? If not, then how do you know it's not a simplification and that's how it is?


    Quote Originally Posted by Farsight View Post
    I'm sorry KJW, but what you've been taught is wrong.
    Do you have any mathematics to back that up?
    A tensor equation that is valid in any coordinate system is valid in every coordinate system.
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    Do you have any mathematics to back that up?
    Unlikely. It was a personal opinion expressed by someone who has not actually bothered to study any of said textbooks, since he manifestly has his mind made up already.
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    I'm sorry, I have to go. The wife is leaning on me. But can I respond to this:

    Quote Originally Posted by KJW View Post
    If I have a clock that ticks one second intervals, then it ticks one second intervals whether it is on the top floor or the bottom floor of a building.
    When you have two such clocks, the lower clock ticks slower than the upper clock.

    Quote Originally Posted by KJW
    And a one second interval on the top floor is the same as a one second interval on the bottom floor
    No it isn't. If it was there would be no such thing as gravitational time dilation.

    Quote Originally Posted by KJW
    This does not conflict with gravitational redshift. Suppose pulses of light are sent from the bottom floor to the top floor each second as measured by the clock on the bottom floor. Then at the top floor the pulses will be slightly greater than one second apart as measured by the clock on the top floor. Quite simply, the interval between the pulses is one second at the bottom floor and slightly greater than one second at the top floor. There is no justification to claim that the intervals at the bottom and top floors should be equal in the sense that the top floor clock has measured the bottom floor interval to be slightly greater than one second. The interval between the pulses at a given location is quite simple the interval between the pulses measured by a clock at that location.
    Intervals between pulses is not how we usually discuss gravitational redshift. There isn't really a gravitational redshift anyway. A pulse of light doesn't change frequency as it climbs. The higher clock ticks faster, so it measures the frequency to be lower. In similar vein a 511keV photon directed into a black hole increases the black hole mass by 511keV/c≤. Conservation of energy applies, and E=hf. The photon energy stays the same, and so does the frequency. What changes are the clocks you use to measure the frequency. And you. And matter. Some of the mass-energy of a falling body is converted into kinetic energy, and when you get rid of this you're left with a reduced mass-energy. So the selfsame photon energy looks higher.
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  58. #258  
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    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by KJW View Post
    If I have a clock that ticks one second intervals, then it ticks one second intervals whether it is on the top floor or the bottom floor of a building.
    When you have two such clocks, the lower clock ticks slower than the upper clock.
    The principle of relativity says otherwise. Consider it a law of physics that the clock ticks at one second intervals, and therefore it does so everywhere. The standard units of measure need to be the same everywhere (implying that the fundamental constants are the same everywhere) in order to provide a stable reference by which the reality at a given location can be characterised. Otherwise, there would be too many unknowns and no meaningful measurements could be made.


    Quote Originally Posted by Farsight View Post
    Quote Originally Posted by KJW
    And a one second interval on the top floor is the same as a one second interval on the bottom floor
    No it isn't. If it was there would be no such thing as gravitational time dilation.
    I already explained why this doesn't conflict with gravitational time dilation (gravitational redshift). I noticed that you omitted "(i.e. it is a one second interval)" from the quote. This makes it more obvious why one second interval on the top floor is the same as a one second interval on the bottom floor by highlighting the meaninglessness of having different intervals called by the same name.


    Quote Originally Posted by Farsight View Post
    Intervals between pulses is not how we usually discuss gravitational redshift.
    I'm choosing to discuss gravitational redshift using intervals between pulses.


    Quote Originally Posted by Farsight View Post
    There isn't really a gravitational redshift anyway
    Then why did you say: "If it was there would be no such thing as gravitational time dilation."? Do you think "gravitational time dilation" and "gravitational redshift" are different?


    Quote Originally Posted by Farsight View Post
    A pulse of light doesn't change frequency as it climbs. The higher clock ticks faster, so it measures the frequency to be lower. In similar vein a 511keV photon directed into a black hole increases the black hole mass by 511keV/c≤. Conservation of energy applies, and E=hf. The photon energy stays the same, and so does the frequency. What changes are the clocks you use to measure the frequency. And you. And matter. Some of the mass-energy of a falling body is converted into kinetic energy, and when you get rid of this you're left with a reduced mass-energy. So the selfsame photon energy looks higher.
    This is largely irrelevant to my discussion of the time intervals between pulses.
    A tensor equation that is valid in any coordinate system is valid in every coordinate system.
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    Quote Originally Posted by PhysBang View Post
    OK, so clearly we have to identify this as a lie...

    You know what, go ahead and ban me for pointing out how deceptive John Duffield is. Maybe he's just crazy...

    I will continue to point out his lying when I see it...

    And that, too, is a lie. Or a sign that Farsight is simply mentally ill...

    Why a lie? Because Farsight doesn't know how to actually use spacetime to do any physics, so when he makes pronouncements about it, he is presenting himself as someone who knows something about the relevant physics. Since he doesn't, he is attempting to deceive the readers of this thread and is arguing in bad faith...

    And this is a lie, because it implies that Ned Wright denies curvature, when curvature is the reason for time delay and Ned Wright knows this...

    Now it could be that Farsight has some sort of mental illness that keeps him from realizing what Ned Wright believes...
    This is a ridiculous tirade. Einstein said what he said, Ned Wright said what he said, and PhysBang said what he said: the speed of light is constant in an infinitesimal region. Which means it isn't constant in the room you're in. Just like the Baez article says:

    "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".

    Now will somebody please moderate this abusive poster please?
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    Quote Originally Posted by Markus Hanke View Post
    It's not defined across an extended region where curvature plays a role, since there is no global notion of time across such a region. Time is a local phenomenon, and hence so is speed. The notion of "coordinate speed" is physically meaningless because it cannot tell us what happens locally at each point.
    We've already established that the tidal force is undetectable in the room you're in, but we have no trouble detecting your pencil falling down. And see above. This difference in speeds is precisely that referred to above by ceiling and floor observers. I'm not just making this stuff up, Markus.
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    Quote Originally Posted by KJW View Post
    Just because the two clocks are 30cm apart doesn't make them local to each other. Local means close enough that any differences are insignificant. A 30cm separation may be insignificant for many purposes, but it is not insignificant in this particular case.
    They're right there in front of your face, a foot apart, and they don't stay synchronised. And they're optical clocks. The lower clock goes slower because "the speed of light varies with position". Not for any other reason.

    Quote Originally Posted by KJW
    This is a logical error.
    It's no error. The speed of light is only constant in an infinitesimal region. It isn't constant in a region 30cm in extent.

    Quote Originally Posted by KJW
    Really? In any of the quotes that you've read, did it say that it wasn't a simplification and that it's how it is? If not, then how do you know it's not a simplification and that's how it is?
    Because Einstein said it, the Baez article said it, and the hard scientific evidence backs 'em up.

    Quote Originally Posted by KJW
    Do you have any mathematics to back that up?
    No. Because mathematics can't prove that a NIST optical clock goes slower when its lower.

    Quote Originally Posted by Markus Hanke
    Unlikely. It was a personal opinion expressed by someone who has not actually bothered to study any of said textbooks, since he manifestly has his mind made up already.
    It's not a personal opinion. You know this Markus. You've seen the Einstein quotes and read the Baez article. Surely? Here it is 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 KJW View Post
    The principle of relativity says otherwise. Consider it a law of physics that the clock ticks at one second intervals, and therefore it does so everywhere. The standard units of measure need to be the same everywhere (implying that the fundamental constants are the same everywhere) in order to provide a stable reference by which the reality at a given location can be characterised. Otherwise, there would be too many unknowns and no meaningful measurements could be made.
    The second is NOT the same everywhere! If it was there would be no such thing as gravitational time dilation.

    Quote Originally Posted by KJW
    I already explained why this doesn't conflict with gravitational time dilation (gravitational redshift). I noticed that you omitted "(i.e. it is a one second interval)" from the quote. This makes it more obvious why one second interval on the top floor is the same as a one second interval on the bottom floor by highlighting the meaninglessness of having different intervals called by the same name.
    The second on the top floor isn't the same as the second on the bottom floor! If it If it was there would be no such thing as gravitational time dilation.

    Quote Originally Posted by KJW
    I'm choosing to discuss gravitational redshift using intervals between pulses.
    Don't. The whole idea of redshift is that the photon frequency appears to be reduced. It appears to shift towards the red end of the spectrum.

    Quote Originally Posted by KJW
    Then why did you say: "If it was there would be no such thing as gravitational time dilation."? Do you think "gravitational time dilation" and "gravitational redshift" are different?
    Yes of course they're different. Gravitational redshift is a perceived effect. The photon appears to be redshifted, but conservation of E=hf energy applies. The frequency doesn't change. It isn't actually redshifted. There is no magical mysterious mechanism by which the photon loses energy. However gravitational time dilation is not like that. An optical clock doesn't just appear to be going slower when it's lower, it is going slower.
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    Quote Originally Posted by Farsight View Post
    Intervals between pulses is not how we usually discuss gravitational redshift. There isn't really a gravitational redshift anyway. A pulse of light doesn't change frequency as it climbs. The higher clock ticks faster, so it measures the frequency to be lower.
    You believe in an absolute reference frame. You just said what you said, so it would be a lie for you to claim otherwise.

    Now, please show us how your inane ideas can actually be used to do a physics application.
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    Quote Originally Posted by Gerry Nightingale View Post
    In reply to PhysBang, re: your #248 post.

    Don't you think you're being little too harsh!? (yikes!...lying? in what manner is an opinion or interpretation a "lie?")

    Oy!...it's just a website that encourages discussions. Nothing is worth being "mean" over!
    Farsight has one argument that he repeats over and over: "Trust me above anybody else, because I'm here with the explanations and reference, I'm here to be challenged and to deal with anything you're dissatisfied with." http://www.thephysicsforum.com/speci...html#post16243

    Given that he is stubborn at avoiding details, all he is offering us is his character. So until he provides details, all he is offering us is his character.
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    In reply to AIP's this thread, re: c

    Is the "tooth and nail" approach going to solve anything? I have doubts of this. "I'm right and you're wrong"...okay, fine.

    .....

    The way to settle a dispute is to set-up a mutually agreed upon scenario, consistent with each others views...and stay with the one "example".

    (no introductions of different references! No other examples of this "factor" or that "factor"! One frame is enough to verify a posit or supposition...if it is not, then the supposition

    is not valid) Just agree to agree on ONE example being adequate for a test of verification. If it leads to something else, then set-up another agreed upon example for further

    debate...if things lead to a stalemate, then both parties would need to re-think their respective positions.

    .....

    Remember Bohr and Einstein? They fought like "cats and dogs" over theory! All the time! Yet they were still friends.


    (Thanks for reading!)
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  66. #266  
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    Quote Originally Posted by Gerry Nightingale View Post
    Is the "tooth and nail" approach going to solve anything?
    No it isn't, PhysBang is being deliberately disruptive. And dishonest. See arXiv for papers with variable light speed or varying speed light or VSL in the title. He's already admitted that the speed of light is only constant in an infinitesimal region, and is trying to cover that up with screaming abuse. I have to say I'm rather surprised there's been no moderation of his quite appalling behaviour. It does not reflect well on the forum.
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    Quote Originally Posted by Farsight View Post
    No it isn't, PhysBang is being deliberately disruptive. And dishonest. See arXiv for papers with variable light speed or varying speed light or VSL in the title.
    Yes, please see those, since they point out that "VSL" theories are wildly different from GR and from what Farsight writes. Interesting that Farisght ties such a search to being "dishonest".

    He's already admitted that the speed of light is only constant in an infinitesimal region, and is trying to cover that up with screaming abuse. I have to say I'm rather surprised there's been no moderation of his quite appalling behaviour. It does not reflect well on the forum.
    Actually, it does. You are deliberately lying about my statement. While I can believe that you have an illness that drives you to ignore learning physics and pontificate about physics, I cannot believe that you take my statement about the speed of light as an endorsement of your crazy theory that alternatives to GR are really GR. And by deliberately lying as a form of argument, you are opening your argument up to discussion of these lies.

    I will admit that it is somewhat dishonest of me to ask you for details since there is ample evidence that you are not competent enough in physics to produce details. However, since only details will meet the requirements of a physics discussion, this is the absurdity that we find ourselves in.
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    In reply to Farsight, re: your #266 post.

    I think of c as an "absolute"...but I could be wrong. So could you...as well as everyone else involved in theoretical physics. Our limited senses reveal just a small fraction of "reality"

    to us...while our minds are capable of grasping and knowing "intangible" concepts.

    .....

    For instance, my eyes and mind think I'm in "real time" as I write this...the reality is that EVERYTHING including the thoughts in my mind are a past-tense of "reality!"

    None of us are ever truly aware of this...yet logic dictates this so, as well as equations. Nothing organic can ever evaluate absolute time/absolute reality as it occurs.

    Chemical reactions are too slow to ever experience more than past-tense "artifacts" of true reality...this is why I have difficulties accepting human evaluations of discrepancies

    regarding "lightspeed". "We" are not capable of seeing anything as it truly is, and unless this factor is acknowledged and compensated for, then misinterpretations of observation

    will occur...especially anything involving relativistic "speeds".

    ....

    I still think you guys should "set-up" something that is agreeable in terms of evaluation...there must be something that can serve as a "DMZ" for the purpose of determinations.


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    Gerry is right. If we cannot find a way to slide a ruler between the the two arguments, then they are just different interpretations of the same thing.
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    Classically light bending in a gravitational field might due the slowing near a large mass I could accept as that would be how a classical extended wavefront could be deflected. However what would be the case for a single photon? It might slow down, but there would be no reason for it be deflected. I wonder what an experiment involving single photons would show?

    I know what I'm putting my money on!
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  71. #271  
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    Quote Originally Posted by Jilan
    However what would be the case for a single photon? It might slow down,
    False.

    but there would be no reason for it be deflected.
    False again, photons , in a beam or isolated follow null geodesics. The null geodesic deviates from a straight line in the case of the experiment that you are considering. I am quite sure that this has been explained to you before.

    Gerry is right. If we cannot find a way to slide a ruler between the the two arguments, then they are just different interpretations of the same thing.
    They aren't "interpretations of the same thing". Only for cranks that cannot tell the difference between what Farsight is claiming and what mainstream science is teaching.
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    XOX, you are dead right, but you are reading too quickly as usual. I was talking about the classical view of a wavefront of light being slowed down, but would you would expect a single photon to slow down too with the argument Farsight is making? The point I was making was that even it did It wouldn't be deflected. I don't think that would be the case. Slow down, think!
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    XOX, you are dead right, but you are reading too quickly as usual. I was talking about the classical view of a wavefront of light being slowed down,
    Light doesn't "slow down". Try to get this in your head.


    but would you would expect a single photon to slow down too with the argument Farsight is making?
    You are just as wrong as before. Early in the 1800's , Soldner showed that a photon is deflected. All by itself. With no "slow down".
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    Quote Originally Posted by Gerry Nightingale View Post
    I still think you guys should "set-up" something that is agreeable in terms of evaluation...there must be something that can serve as a "DMZ" for the purpose of determinations.
    These things exist in abundance: there are many physical systems that serve as tests for gravitational physics. All Farsight has to do is pick one, use his interpretation to describe in detail what is happening, and then we can evaluate this.

    Earlier in this thread, the Shapiro time delay was presented. In this case, the change in time created in GR was used to motivate a claim that light moves at a slower speed past the sun when considering movement vs. a certain set of extended coordinates. Farsight claims that we can start with the slower speed of light and recover everything. If he would demonstrate this, then we would all be a lot happier.
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    To xox, er.... that is the point I was making I was referring to Farsight's view that light might get slowed down, which I don't think is the cause for deflection. You do need to read things more carefully IMO. Even if it was the reason it couldn't explain why a single photon would be deflected.

    Taking this in a step on if I may, the QM statistical type view might suggest that the reason a single photon would get deflected is that there are more available states closer to the large mass. Now why would that be I wonder.?......
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  76. #276  
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    Quote Originally Posted by Jilian
    Er.... that is the point I was making
    Based on your posts and your misunderstandings, you are just lying. See here:

    Quote Originally Posted by Jilan
    Classically light bending in a gravitational field might due the slowing near a large mass I could accept as that would be how a classical extended wavefront could be deflected.
    I was referring to Farsight's view that light might get slowed down, which I don't think is the cause for deflection.
    OK, now you are contradicting yourself. So, what did you learn? What is the cause for deflection?

    Taking this in a step on if I may, the QM statistical type view might suggest that the reason a single photon would get deflected is that there are more available states closer to the large mass
    Nope. Making up more BS to cover up your previous BS. Nothing to do with QM.
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    Xox, what part of 'however" in my post 270 do you do not understand? Please tell me English is not your first language and I will make allowances for your appalling attitude.
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    Classically light bending in a gravitational field might due the slowing near a large mass
    False.

    I could accept as that would be how a classical extended wavefront could be deflected.
    This puts you firmly in Farsight's camp. Congratulations!


    However what would be the case for a single photon?
    As already explained, there is no difference between the case of a bunch of photons and a single one. Placing a "however" at the beginning of the sentence doesn't make it less wrong. So, you are grasping at straws trying to cover up your previous crankiness.


    It might slow down,
    Refreshing to see you and Farsight on the same side of the argument again.



    but there would be no reason for it be deflected.
    false. again. keep up the good work.
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    Xox, I really am losing patience with you as you seem to wilfully misreading every post I make. I was attempting to show that even if the light slowing theory might explain deflection in the classical sense, it won't in the quantum sense. Again what part of "however" is passing you by? If you won't answer the question you really should avoid posting anymore on this thread. It's getting irritating and I'm not usually easily irritated.
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    In reply to xOx, re: your #278 post.

    What if there are NO "corpuscular" photon "packets-of-energy" at all? What would it mean? The end of modern physics theory, or a new beginning of understanding that "emission" theory

    was never needed...something that should have stayed in 17th.C. I have read some work that says "emission of sub-atomic electrons and photons from a source" is not valid, and never

    was valid! This sounds very "cranky" to me! (how could such a theory work?)

    .....

    I have been reading Jilan's posts for 7 months now...I have never seen any "crank" involved! Except for the plague of mongeese she mentioned last April, she seems pretty "steady" to me.


    (Thanks for reading!)
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  81. #281  
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    Quote Originally Posted by Jilan
    Xox, I really am losing patience with you as you seem to wilfully misreading every post I make.
    I am simply pointing out the gross errors in your posts. <shrug>

    It's getting irritating and I'm not usually easily irritated.
    Well, there is an easy solution: stop posting new crank stuff and I will have nothing new to post. Posting new crank ideas to cover your previous crank ideas triggers new responses. <shrug>
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    In reply to xOx, re: this thread.

    Is there anything in modern QM which is established as an absolute FACT? I'm curious...I've been reading various aspects of QM theory for about forty years now, and not once have I

    seen anything "proven beyond question". Are there any posits that have found to have 100% reliability?

    .....

    Do you know of any references that I could read?


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  83. #283  
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    Quote Originally Posted by Markus Hanke View Post
    Everyone, please remember that "speed" is a concept that is not as straightforward as it would initially seem, because we need to distinguish between coordinate speed and proper speed. In curved space-times, the coordinate speed of light does indeed vary, but proper speed does not. It is now crucial to understand that there isn't a contradiction between these.
    In general relativity (and in special relativity as well) the 4-velocity of ANYTHING is c. I assume that this what you mean by "proper velocity" as it is the speed associated with proper time. There is nothing mysterious here, as it is simply a logical consequence of the Lorentzian metric of spacetime and the fact that arc length and proper time are related by the constant multiple "c".

    Coordinate time and coordinate speed are artificial concepts and, as implied by the name, are dependent on the particular choice of coordinates that are used. Thus they are aartificial concepts and not fundamentally meaningful.

    On the other hand, localization is meaningful. One must remember that the localization of general relativity is special relativity. As everyone should know the speed of light in special relativity is a constant, "c". In fact the constancy of the speed of light is a fundamental axiom of special relativity and hence the local speed of light in general relativity is also fundamental, and in fact is intimately tied to the metric of spacetime.

    Farsight has been touting his so-called "variable speed of light" nonsense all over the internet for years, misrepresenting Einstein along the way. There is zero merit in this "theory". The speed of light is "c" in either a local sense or in the sense of 4-velocity, always and everywhere. It is true that you can create coordinates in which the speed is something else, but that is an artifact of an artificial choice of coordinates and is not representative of any fundamental physics, although the effects can be quite useful, and in fact measured in experiments (in any experiment at some point you simply must relate quantities being measured to some local coordinate system. For instance, so-called gravitational time dilation is a coordinate effect, but it can and has been measured (Pound). In the Pound-Rebka experiment one is dealing with coordinate times, not the proper time that is what clocks measure in general relativity. Proper time is always local and always progresses at the rate of one second per second, but one can attempt to relate coordinate times at spatially separated points and that is what one is discussing when one talks about "gravitational time dilation".

    General relativity takes place in the setting of a Lorentzian manifold. Only those concepts that one can formulate without specific reference to a coordinate system can be guaranteed to be physically meaningful. This is the content of Einstein's insistence on "general covariance". Anychoice of a coordinate system may result in invalid conclusions, since no coordinate system is gglobal (such is the nature of a general differentiable manifold). All sorts of erroneous coonclusions have resulted from misapplication of coordinate systems -- for instance it was once thought that the event horizon of a Schwarzschild black hole was singular, which it most certainly is not, due to the limitations of the coordinate system in which the black hole was first analyzed.

    Farsight will show you all sorts of pretty pictures and make clever, but erroneous, arguments. His knowledge of physics in general and relativity in particular is zero. In fact it is less than zero, since the bulk of what he knows is wrong.

    It is fortunate that his nonsense has been moved to Personal Theories and Alternative Hypotheses. It is unfortunate that the policy that no such sub-forum was to be part of the Physics Forum has been reversed. Why one would establish a venue for the discussion of pseudoscience and nonsense in what was supposed to be a forum for the discussion of real physics is a total mystery to me.

    Anyone who wishes to waste some money can but the book Relativity+ by John Duffield (aka Farsight) and read delusional physics to his heart's content. RELATIVITY +: The Theory of Everything: John Duffield: 9780956097804: Amazon.com: Books. Note this is published by one of the various "vanity presses" (publication costs paid by the author) since no reputable publishing house would touch this with a ten foot pole. There is much better fiction available at a much better price.

    I have posted this is response to a conversation with Speedfreek, but if the policy here remains one of any support at all for discussion of the sort of nonsense personified by Farsight then I will not repeat this lapse. Farsight has been debunked repeatedly by experts all over the internet (and elsewhere), but nothing dissuades him from espousing utter nonsense. There is little to be gained from doing it again. Fools will believe what they will. Serious students of science can recognize charlatans quickly enough. Farsight will never recognize reality.
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  84. #284  
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    Quote Originally Posted by DrRocket
    Anyone who wishes to waste some money can but the book Relativity+ by John Duffield (aka Farsight) and read delusional physics to his heart's content. RELATIVITY +: The Theory of Everything: John Duffield: 9780956097804: Amazon.com: Books. Note this is published by one of the various "vanity presses" (publication costs paid by the author) since no reputable publishing house would touch this with a ten foot pole. There is much better fiction available at a much better price.

    I have posted this is response to a conversation with Speedfreek, but if the policy here remains one of any support at all for discussion of the sort of nonsense personified by Farsight then I will not repeat this lapse. Farsight has been debunked repeatedly by experts all over the internet (and elsewhere), but nothing dissuades him from espousing utter nonsense. There is little to be gained from doing it again. Fools will believe what they will. Serious students of science can recognize charlatans quickly enough. Farsight will never recognize reality.
    I agree, John Duffield threads really belong in Trash (like his "book")
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    In reply to Dr. Rocket, re: your post #283.

    I agree with "c" as an invariable.

    .....

    I do NOT agree with your personal assessment of "Farsight" (if you think his stuff is drivel...you would think him a paragon of knowledge compared to my "stuff")

    As far as "internet experts" are concerned, I will wait awhile to find one. "Me" included.

    You say you basically "will not post" unless Farsight is removed? ("banned" or just not allowed to post in "alternate theories?") Why? If your convictions are firm (as are mine) then

    what is the problem? I don't agree with Farsight at all w/ regard to "VSL" and yet I would still like to be able to read what he has to say! Why not? There is always a chance he

    might actually hit on something that no one has thought of yet! It has happened before (1905) and may happen again. If not Farsight, then perhaps you or someone else might actually

    have something valid that "shakes things up".

    .....

    "Utter nonsense?" Why did Einstein NOT receive a second "Nobel" for GR? GR is either valid or it isn't...yet many have received the Prize for what amounts to "fingernail parings" of

    theory! GR IS VALID...and yet no official acknowledgement. "Well...it is too esoteric to "prove" GR is valid in all circumstances, so therefore we cannot say it is true" is analogous to

    stating "BB" is all but proven as fact!" There are huge quantities of experiments to "prove" GR, as well as empirical evidence...yet "BB" has "more validity?"

    .....

    My point is that even A.E. is still doubted...and if there is or was a better theoretician, I would like very much to know "who" it is!

    Is Farsight equal to Einstein? YES...in terms of being able to "post" what he thinks may be a true circumstance, as he sees it. Is Farsight another A.E.? NO...but neither is anyone else.

    .....

    If you think an "alternate theory" is "unworthy of real physics"...then what should be posted as "real physics?" Just texts? Quote mining? Or just what you and several others say is "right?"

    How would anything "new" ever be known? (You know as well as I do that all academic "sites" are "closed loops")

    .....

    FYI...Einstein was first published at 16 by various "pseudo-science" magazines prevalent in Germany at that time. You could easily call them the paper "internet" of that era. Many of

    those magazines refused to publish his first paper dealing with magnetic-field theory, labeling them as "unprovable nonsense!" (there were harsh critics then also)


    (Thanks for reading!)
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    You do know you are slamming every physics student trying to get an education as nothing but a stupid retard?
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    Great post Dr Rocket. I can follow it 100% which is credit to you and many others on this site. In 2013 I wouldn't have understood most of it. In fact in 2013 I had little interest in General Relativity. It was the forum and all the contributors that made this possible. If these threads had never been started I would still be thinking that the event horizon was some kind of real singularity! Could I have learned all this from a book? Sure, but it would be a dull and lonely endeavour. We are creatures that talk and this is how we learn best, whether that be attending a lecture, watching a video, having a tutorial or discussing things on forums. I wonder if they banned speakers with non-mainstream views from the forum in Ancient Rome or just put them in a corner somewhere?
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    Quote Originally Posted by DrRocket
    In general relativity (and in special relativity as well) the 4-velocity of ANYTHING is c.
    Not so. 4-velocity is a 4-vector whereas c is a scalar. Second, c is only the magnitude of the 4-velocity. And last but not least you canít say ďanythingĒ because light/a photon doesnít have a 4-velocity so its magnitude certainly canít be c.
    Quote Originally Posted by DrRocket
    Coordinate time and coordinate speed are artificial concepts and, as implied by the name, are dependent on the particular choice of coordinates that are used. Thus they are aartificial concepts and not fundamentally meaningful.
    Also not so. What one measures in the lab is coordinate time and speed so you can hardly say that itís meaningless or artificial. SR has a great deal to do with the fact that, in general, what one measures depends in their frame of reference is not the same as what one measures in another frame of reference moving relative to the first. If this wasnít the case then the most important things we have learned and tested from special relativity, such as time dilation and length contraction, would be meaningless because a coordinate system and an observer are one in the same thing. This is an important fact that many people donít understand and therefore misinterpret.
    Quote Originally Posted by DrRocket
    Farsight has been touting his so-called "variable speed of light" nonsense all over the internet for years, misrepresenting Einstein along the way.
    Thatís a well-established fact in general relativity. In fact itís exactly what Irwin Shapiro wrote in his published papers on his radar ranging experiments when he and his team at MIT did those experiments to measure what is now called the Shaprio delay.
    From Fourth Test of General Relativity: Preliminary Results by Shapiro et al, Phys. Rev. Letters. Vol 13(26), Dec. 28, 1964
    Because, according to general relativity, the speed of a light wave depends on the strength of the gravitational potential along its path, these time delays should be increased thereby be increased by almost 2x10^(-4)s when the radar pulses pass near the sun.
    From Fourth Test of General Relativity by, Shapiro et al, Phys. Rev. Letters, Vol 20(22), May 27, 1968
    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 increasing gravitational potential.
    You can find this in modern literature by looking at Taylor and Wheeler, Foster & Nightingale, and Ohanian & Rufinni to name three of them.
    Quote Originally Posted by DrRocket
    The speed of light is "c" in either a local sense or in the sense of 4-velocity, always and everywhere.
    This too is wrong. A 4-velocity canít be defined for light, (canít divide by proper time = 0).

    Whatís with all the ad hominems regarding Farsight?
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    In reply to Jilan, re: your #287 post.

    Cheers!

    In the time of Rome as empire, public speaking was regarded as the mark of an intelligent, sophisticated person...a true Roman of worth! (It was possible for what would be considered

    a "slave" now to give an "oratorio" and find themselves granted citizenship...or suffer having a tongue cut-out for a "poor" oratory) They took public speaking very seriously with many

    mandates and rules, esp. if there was a debate involved...a career or position could be lost by a poor performance! (if you could not speak well...it would be impossible to hold any

    "high office" in the time of the "Rome as Empire"...no "Dubya" could have been a Senator, much less a Caesar!)

    .....

    "Banishment?" Yes, they had that...but it was possible to redeem one's "poor" speech with a better one. (better redemption than life in exile among uncouth "barbarians") It had better be

    a good speech though! Or else...


    Thanks for reading!)
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  90. #290  
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    A further reply to Jilan.

    What do you think of #288? "Time dilation?" et al. (I'm curious as to your "take" on the question of using "d/t" evaluations as definitive of c value(s) )

    Cheerio!
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  91. #291  
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    Gerry, my take on it is that the speed of light will be measured to be the same in each inertial frame of reference as c. It will also be measured to be c in a different inertial frame of reference too as the time dilation and space contraction cancel each other out. It won't be measured to be c however in a different FOR which is a non-inertial FOR. It's a frame dependent phenomena. That's why it is incorrect to say that the gravitational field changes the speed of light. The measured speed depends on where you are when you are measuring it, it's observer dependent, nothing to to with a property of the light itself.
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  92. #292  
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    In reply to Jilan, re: your #291 post.

    You get a BIG cupcake for this! Complete with gooey frosting and possibly sprinkles!

    You DO understand Relativity and the implications as they apply to any frame...good on ya' !

    .....

    I cannot see time "dilation" as valid, however. (I just can't make myself accept it...and I've really tried)


    Cheerio...and thanks for the reply.
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    Quote Originally Posted by Physicist View Post
    Not so. 4-velocity is a 4-vector whereas c is a scalar. Second, c is only the magnitude of the 4-velocity. And last but not least you canít say ďanythingĒ because light/a photon doesnít have a 4-velocity so its magnitude certainly canít be c.

    Also not so. What one measures in the lab is coordinate time and speed so you can hardly say that itís meaningless or artificial. SR has a great deal to do with the fact that, in general, what one measures depends in their frame of reference is not the same as what one measures in another frame of reference moving relative to the first. If this wasnít the case then the most important things we have learned and tested from special relativity, such as time dilation and length contraction, would be meaningless because a coordinate system and an observer are one in the same thing. This is an important fact that many people donít understand and therefore misinterpret...
    Save your breath Physicist. You're up against dogma and abuse and censorship here, not a level civil physics discussion.

    Quote Originally Posted by Physicist View Post
    Whatís with all the ad hominems regarding Farsight?
    He can't counter the argument or the evidence.
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  94. #294  
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    Quote Originally Posted by Farsight View Post
    Save your breath Physicist. You're up against dogma and abuse and censorship here, not a level civil physics discussion.

    He can't counter the argument or the evidence.
    Thanks for the warning, John. I'll stay out of this thread. I don't care for all the ad hominems that are being tossed around.
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  95. #295  
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    Quote Originally Posted by Physicist View Post
    Thatís a well-established fact in general relativity. In fact itís exactly what Irwin Shapiro wrote in his published papers on his radar ranging experiments when he and his team at MIT did those experiments to measure what is now called the Shaprio delay.
    From Fourth Test of General Relativity: Preliminary Results by Shapiro et al, Phys. Rev. Letters. Vol 13(26), Dec. 28, 1964
    But this is not what Farsight is saying. Farsight is saying that the fundamental change in GR is the speed of light at the level of the manifold and this, in turn, causes all other relativistic effects.
    Whatís with all the ad hominems regarding Farsight?
    This topic seems to come up a lot. "ad hominem" is a fallacy of the type where someone discusses something not relevant to an argument rather than the argument. Certain claims about the way that Farsight argues are relevant because they are part of the argumentation offered (e.g., lpetrich pointing out the theology-like nature of Farsight's claims).
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  96. #296  
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    Quote Originally Posted by PhysBang View Post
    But this is not what Farsight is saying. Farsight is saying that the fundamental change in GR is the speed of light at the level of the manifold and this, in turn, causes all other relativistic effects.
    I see. Thanks for correcting my misunderstanding PhysBang.
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  97. #297  
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    Quote Originally Posted by Jilan
    It won't be measured to be c however in a different FOR which is a non-inertial FOR. It's a frame dependent phenomena. That's why it is incorrect to say that the gravitational field changes the speed of light. The measured speed depends on where you are when you are measuring it, it's observer dependent, nothing to to with a property of the light itself.
    It simply makes no sense to claim that one can measure the speed of light remotely. To fix the ideas, an observer located at radial distance from the center of a black hole, measures the speed of light to be no matter the value of . But an observer at infinite distance from the center of a black hole measure the speed of light at the radial location as where is the Schwarzschild radius of the black hole. The former measurement is physically meaningful, the latter, isn't.
    Another example: an observer stationary (non-rotating) in the center of a Sagnac setup measures the speed of light to be . An observer rotating with the platform, measures the speed of light as , where is the radius of the Sagnac platform and is its angular velocity. The rotating observer doesn't really measure the speed of light, what he's measuring is the "closing speed" between him and the light wavefront.
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    In reply to Jilan, re: the value of c.

    Cheers!

    "Great distances render the constant factor useless"...really? "Blackbody or "Hole" entities also render "c" moot".

    ......

    I find these implications startling, at the least. Such an assessment would mean that the rules and properties of matter/energy/gravity can be ALTERED by the circumstances of distance

    from the point of observation and the density of the "mass in place!" <(a Star)

    ......

    The empirical reality of the Solar system is also reduced to "false values" (after all, one cannot have a firm set of "rules" here and then dictate the "rules" can be altered over "there" because

    observations and speculations concerning "there" are correct)

    ......

    I am now completely uncertain as to "what is "fringe invalid theory" and what is not! (Einstein's masterwork is rendered false with every "post" that states c can vary according to distance)


    Cheerio!
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    Quote Originally Posted by x0x View Post
    It simply makes no sense to claim that one can measure the speed of light remotely. To fix the ideas, an observer located at radial distance from the center of a black hole, measures the speed of light to be no matter the value of . But an observer at infinite distance from the center of a black hole measure the speed of light at the radial location as where is the Schwarzschild radius of the black hole.
    Could you not apply the same argument to the concept of time dilation or length contraction too? If different reference frames are not physically meaningful we would have no requirement for relativity, don't you think?
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  100. #300  
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    Quote Originally Posted by Gerry Nightingale View Post
    In reply to Jilan, re: the value of c.

    Cheers!

    "Great distances render the constant factor useless"...really? "Blackbody or "Hole" entities also render "c" moot".

    ......

    I find these implications startling, at the least. Such an assessment would mean that the rules and properties of matter/energy/gravity can be ALTERED by the circumstances of distance

    from the point of observation and the density of the "mass in place!" <(a Star)

    ......

    I am now completely uncertain as to "what is "fringe invalid theory" and what is not! (Einstein's masterwork is rendered false with every "post" that states c can vary according to distance)!
    Gerry, I can appreciate your confusion. Einstein said that the laws of Physics (and the speed of light) will be the same in all inertial frames of reference. (These are frames Of reference that are not acclererating with respect to each other). But if one reference frame is accelerating with respect to another they will not measure the laws of Physics to be the same in the other reference frame as it is in theirs. As XOX points out if both frames are accelerating at the same rate you see no discrepancy.

    In General Relativity the effects of gravity have an equivalence to an accelerating reference frame. If you are closer to the massive object then the effect is stronger (and the related acceleration greater) due to the inverse square law. So if you are closer to the massive object than I am it would be equivalent to your frame of reference having a greater acceleration than mine. Our frames are not inertial frames and the discrepancies arise. So in that case our relative positions become important. Note though that both of us will still measure the light at our local postion to be c.
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