Neutrinos faster than the speed of light?

Discussion in 'Physics & Math' started by Magical Realist, Nov 1, 2013.

  1. nimbus Registered Senior Member

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    Aqueous Id and brucep and all thanks for the welcome. Thanks burcep for worked example of light delay, I have printed it off and leaving it loose in back of book. Very attention holding thread.
     
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  3. Aqueous Id flat Earth skeptic Valued Senior Member

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    Hey you're welcome. Thanks for your refreshing entry into a discussion "hitting the ground running" as a new member and contributing to the overall inertia.

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    .

    It's funny how, when a person takes an extreme position on a discussion of this kind, it incites us to rethink the ways we might describe what we know -- or at least think we know. There's a lot of profit from this, since it makes us retrace our steps from all kinds of angles we wouldn't normally have bothered with.
     
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  5. exchemist Valued Senior Member

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  7. brucep Valued Senior Member

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  8. brucep Valued Senior Member

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    That's why I look forward to your comments. Seems like your perspective will include some mention of the evolution of the idea beyond just what it is now. A book about the evolution of an idea, and much of the history that proceeds it, is Alan Guth's 'The Inflationary Universe'. Anybody who thinks folks are doing this for the money should read this book. He's working on this idea while wondering if he'll be able to keep his professorship at the University and house and feed his family. Never having worked at a University I didn't understand what 'tenure' means to folks doing scientific research while teaching.
     
    Last edited: Dec 10, 2013
  9. brucep Valued Senior Member

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    I'm jealous of you. Reading that book was my first real scientific learning experience and it's still my favorite.
     
  10. pmb Banned Banned

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    Although I won't be able to meet with Dr. Shapiro until next year I instead hunted down his publications on his research. However in an e-mail he told me that the time delay due to spatial alterations is small compared to the portion which is due to the change in the speed of light.

    In Fourth Test of General Relativity Irwin Shapiro, Phys. Rev. Lett. Vol 13(26) Dec. 28 1964.
    In Fourth Test of General Relativity: Preliminary Results by Irwin I. Shapiro, et al. Phys. Rev. Lett., Vol 20(22) May 27, 1968. The second sentence reads (Note: "usec" = microseconds)
    So there you have it. The very purpose of the experiment was to verify the prediction that the speed of propagation of a light ray decreases as it passes through a region of increasing gravitational potential.

    I knew this was the case of course. After all I know when to trust the GR pros when so many of the prominent experts state in no uncertain terms in their GR textbooks that this is exactly the case. Why you all think you know better than all of the pros who al agree with each other is beyond me.

    If you ever decided to closely study the Shapiro time delay out of any or all the GR texts I quoted for you and provided you with links to actually download the texts, then keep in mind two important facts – The “t” in the Schwarzschild metric is the coordinate time (what Taylor and Wheeler call “faraway time”) is the time recorded on clocks located far away from the source of gravity, i.e. to regions of space where the gravitational field does not significantly slow down the clock enough to be concerned with. This is the time with which the speed is being measured with, i.e. it’s the “t” in the

    “coordinate speed of light = dr/dt = 1 – 2M/r

    Be very careful to take notice of why the light is slowing down. In that part of the motion where the spatial path is unaltered (i.e. the tangential portion) the light slows down because the time with which the speed is being measured slows down. In those parts of the field where there are altered spatial relations then that too contributes to the time delay. I.e. part of the delay is due to the added distance caused by the "stretching" of space by the sun, i.e. due to the non-Euclidean nature of space around the sun due to the 1/(1 - 2M/r) term in front of the dr^2 term in the metric.

    It’s too bad grumpy wasn’t open minded enough to read the paper for himself instead of wrongly predicting what Shapiro would say about it. Lol!!
     
    Last edited: Dec 18, 2013
  11. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    pmb

    So you think Shapiro supports your position?

    If it grazes the solar limb it is a bent path(bent twice in this experiment)and the delay is caused by light having to travel more distance on that bent path. The transit time will be longer than the coordinate distance divided by lightspeed is. But the light at no time travels at any other speed than lightspeed. Period. Same thing happens in gravity lensing every day. An image appearing in the center of a lensing mass takes less time to travel than a lensed image on the outskirts of the lensing mass. A little geometry and that delay will give you a very accurate relative distance to the object being lensed. Shapiro did not show slow light, he just confirmed bent spacetime. No New York Times front pages, no Huffington Post freak out, no old physicists pulling their hair out, no Nobel for you, no slow light, just Einstein confirmed(again).

    Grumpy

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  12. pmb Banned Banned

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    Good Lord, you're just plain gone.

    And you have it backwards, crackpot. He doesn't support my position. I support his position. For cripe sake he stated that in no uncertain terms when I was 4 years old! Who am I to say he learned it from me? He's the one who said it in the articles he wrote.
    I remind you that it was you who suggest that I ask him. You can't accept the fact that you don't understand.

    I’m still amazed at how many times this has been explained to you by quite numerous GR experts and you still can’t fathom it. That’s just a sign that you’re simply not willing to listen and understand it, period!

    How is it you can sit there with a straight face and expect any reasonable person with the skills to understand GR to expect that you're right and all the GR pros whose texts I quoted to you and gave you a link to are all wrong? Never mind. Don't bother answering. I never read your posts since they have nothing worthy of reading in them. I don't read crackpot physics and that's what you keep posting on this point.

    Why do insist on not paying attention?

    I've explained the error of your ways countless times and yet you still can't grasp it.

    There is two reasons for the delay (1) the motion parallel to the dr direction has to travel an extra distance due to spatial curvature and (2) the gravitational time dilation which makes the light slower. I showed you how this worked in the derivations but yiu just don't have the skills to comphrend them. That's why you can't understand that what you're posting is utter garbage, i.e. crackpot physics.

    Your entire problem is your inability to comprehend the math involved - Period.

    Even when it was made very simple you stil couldn't grasp it. E.g. when I gave you Einstein’s very first derivation from his 1911 paper where he used a uniform gravitational field where there is no spatial alterations and still the light will slow down and you were unable to grasp that too. And by the way, the bending of the light by the sun can be neglected for this problem as Ohanian demonstrates in his book. Maybe when the fear lifts you'll dare to read it?

    Wrong again, crackpot! No soup for you.

    You know, don’t you, that you can claim whatever bs that you want to. It still won't change what’s recoreded to be the truth in all the GR texts I’ve shown you and which you have to ignore so that you’re not so embarassed. I've given you the correct derivations plenty of time and you’ve shown me that you don’t understand any of it. Why do you think you can bs me with your crackpot nonsense?

    This latest sad attempt at a heuristic description fails beyond miserably. You simply will never learn this until you stop yammering, pick up a book GR textg and start learning GR!!! Then and only then will you understand why the entire GR community is telling you you’re wrong.

    Period!

    At least now it’s pretty clear why you're just a science enthusiast and not a real scientist. You don’t have the mind for it because you can’t learn from your mistakes.

    Back to the kill file where you belong.

    As far as the rest of you – notice how grumpy is too scared to e-mail not one single GR pro and prove to them that their GR text is wrong where they state that light slows down in a gravitational field. LOL!!!
     
  13. pmb Banned Banned

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    By the way, - I know that you think that its the longer path taken by light because the path is bent that accounts for the time delay but that's the problem. That's 100% wrong - You're not listening. Anybody who understands the math knows that to be false. SAying that proves that you don't understand the details of a calculation and by the way you described it tells us again that you don't comphend what it is that you're saying. The details of the calculations and what ever single symbol and path way worked with states that what you're saying is not only false but that you dont understand what it is your talking about. That's whywhen I showed you the calcuation I could tell you what every single symbol and line lement meant. You, on the otherhand, did nothing more than absolutely vauge hand waving. That you absolutely refuse to learn all of this by reading even one of the GR textbooks I showed you just proves to me that you're not willing to learn the subject and are happy passing around missinformation.

    If it was only a bent light beam and not time dilation and spatial altgerations then you'd be right. If it was even just spatial alterations, you'd be right. The slowing of light is a direct result of the time dilation, i.e. the time of passage of the light moving through a gravitational field was measured by an atomic clock located on earth outside the field that is causing the delay. If the time coordinate was chosen to be that measured by a clock inside the field then there'd be no time delay and hence the slowing of light.
     
    Last edited: Dec 18, 2013
  14. nimbus Registered Senior Member

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    I note That wolfgang Rindler, one of those experts, has been quoted in EBH first edition. Page 4-9
    Rindler’s saying there’s no force, do you agree with him? And will you be e-mailing him to tell him his wrong if you don’t agree with him?

    I think what your saying about the Shaprio delay, is that the time dilation contribution is greater than the curved spatial contribution, I have read that somewhere too. Aho
     
  15. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    pmb

    Again, where is the NYT headline that Shapiro has proven Einstein wrong? He predicted that the light path near the sun's limb would be bent, that the path would thus be longer. Shapiro sent his radar beam(light by any other name)by the sun's limb twice, he got twice the delay, compared to the KNOWN Cartesian coordinate distance. Every physicist will tell you the delay is because of bent spacetime, you interpret it as overthrowing a basic tenet of physics. I think all we have here is a crackpot pushing bull feces. I taught physics for over thirty years but I grew up in the country, I know the smell.

    Grumpy

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  16. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    pmb

    I notice you seem to be arguing from the authority of a specific set of experts. I also noticed earlier inclusion of Farsight in the conversation. When you have a circle of crackpots around you you're unlikely to know what you're talking about. As far as arguing math, it's a smokescreen. You can prove anything with math, it may or may not have anything to do with reality. It depends on the assumptions you put in on the front end, or garbage in, garbage out. If you can't explain it on basic principle WITHOUT the math, you can't prove it WITH the math. The principles come first, math is a tool we use to nail them down to specifics.

    nimbus

    WR is only partially correct. Mass bends spacetime, bent spacetime is gravity. The map Einstein made is a more accurate model of reality. If reality acts like spacetime who are we to argue with that? If someone comes along with a better, more accurate map, we'll use that one. So far, nada.

    Grumpy

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  17. nimbus Registered Senior Member

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    Ooo
     
    Last edited: Dec 18, 2013
  18. nimbus Registered Senior Member

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    Sorry Grumps, I was asking pmb if he ( not you) would be e-mailing WR to tell him his wrong about there being no force.
     
  19. brucep Valued Senior Member

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    Just to say this to you. There is no 'time dilation contribution' associated with the natural path of light in the tangent space [local approximation of flat spacetime, Minkowski metric]. That distance is invariant. The tick rate [time] is recorded by a clock local to the experimental measurements.

    Derived from the Minkowski metric

    setting dTau at 0 [the proper time for light] and dphi at 0

    0=dt_meter^2 - dr_meter^2

    dr_meter^2=dt_meter^2

    dr_meter/dt_meter=1 [c=1] [it's invariant in the tangent space which represents the local part of the gravitational manifold that we can approximate as flat spacetime]. A practical way to think about this is 'at every point in the universe'. Everywhere.

    This is the derivation pmb is trying to obfuscate.

    Setting dTau=0 and dphi=0

    The Schwarzschild metric

    0=(1-2M/r)dt_bkkpr^2 - dr^2/(1-2M/r)

    0=(1-2M/r)^1/2 dt_bkkpr - dr/(1-2M/r)^1/2

    dr/dt_bkkpr = 1-2M/r [remote radial speed of light in Schwarzschild coordinates]. Where the remote bkkpr reckons the remote [coordinate] speed of light is 0 at r=2M. This is an example of somebody concluding the path of light is time dilated and length contracted. Awhile back it was claimed that the LIGO experiment wouldn't be able to detect gravitational waves because the experiment was set up wrong [cranks, don't you just love them]. The reason it was set up wrong was Kip Thorne and the CalTech team didn't account for the length contraction over the path of the gravitational waves. Essentially canceling any chance that a passing gravitational wave would result in movement of the test blocks. Assuming that the path of light is time dilated and length contracted is a sure sign of 'brain dead' physics. Concluding that Einstein proved that the speed of light is a variable is a sure sign of 'brain dead' physics. At a very basic level a knowledge of spacetime geometry should preclude making 'brain dead' predictions about the variable speed of light. One component of the geometry is an invariant [what could that be? LOL]. Everybody should know that if they want to say something about the theoretical predictions of GR. The ones that have been shown to describe natural phenomena.
     
  20. exchemist Valued Senior Member

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    pmb, I know you won't thank me for telling you this, but you are coming across more and more like a hysterical nutcase as this goes on. This is not a good strategy for winning the battle of ideas.

    I'm a mere observer of this debate, but I can follow fairly easily what Grumpy and brucep are saying, whereas I'm afraid I can't follow you at all. It may be that I'm too stupid, but then again, I find myself wondering if there could be another explanation……..
     
  21. Aqueous Id flat Earth skeptic Valued Senior Member

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    Hi exchemist.

    He is very confused. He can't fathom the parallel existence of two realities - the one we think is real, and the other one that we know is proceeding in its own time and space. He seems to think that the apparent slowing of light in a gravity well is identical to an actual change in the speed of light.

    This would be analogous to saying that the redshift seen in distant objects is not apparent at all, but the exact way the signal was emitted from the sources. I guess it's the same as saying that the rise and fall of a passing siren is not apparent either, but merely the actual change in pitch within the siren (with a very nonsensical "pseudo-egocentric view" that all sirens are waiting to pass ME before altering their pitch.)

    He knows that the space which the light is traversing is itself warped, relative to the observer, but he still insists that the light speed itself is changing. This, rather than accounting for the delay by simply acknowledging that the assumption made about the true distance the light travels was wrong when the transit time was calculated prior to the experiment.

    He's laying it on thick with that appeal to authority argument. The downside of this is that the authors are not stuck in this hole that he's in. He's just pretending they are. Or I suppose he actually thinks they are.

    Not sure what his game is, but it's odd that he holds court here from time to time and challenges folks that have the academic chops which he never developed. Not that this is unusual. He's one of dozens of such folks I've engaged at Sci since I got here a couple of years ago.
     
  22. exchemist Valued Senior Member

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    Thanks for the synopsis. He and I had a good dialogue about the Uncertainty Principle a short while ago (once I had got him to stop patronising me). I got the feeling though that while the maths looms very large in pmb's view of things, the picture of physical reality that the maths represents is sometimes less clear. This, I think, is the problem I have with interpreting what he says.

    I do hope he does not go bothering Shapiro too much. The guy is 84 and entitled to a bit of peace - also there is the question of how sharp his intellect still is.
     
  23. pmb Banned Banned

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    When my curiosity got the best of me and I decided to see what Grumpy was using as an argument to justify his claim that that light doesn’t slow down in a gravitational field.

    I’ve chosen to ignore everyone else’s comments because they’ve made a conscious decision to ignore all the general relativity literature on this subject because it demonstrates that all of you are wrong so your comments are not worth considering. I posted at least four different general relativity textbooks on the subject of the slowing of the speed of light. You ignore all of it and I have no respect for people who willingly and consciously choose to remain ignorant. I’ll have nothing to do with people who ignore facts which prove them wrong and this place is full of them.

    When I read Grumpy’s last post I saw with the rest of you that he’s confusing the deflection of light in the gravitational field with the slowing of light. No physicist worth their salt would ever use some a hand waving argument, because they are devoid of any reason why the bending is the sole cause for the entire value for the time delay measured by Shapiro’s team.

    From Grumpy’s response it finally became clear that the reason he, and perhaps everyone else, keeps making this mistake is because he doesn’t have the required education, understanding and the skills in the math and physics required to follow and understand all of the derivations provided in both my website and in all the references provided to him. The fact that the path was bent plays no role in the value of the measured value of the time delay because it was so small. This problem had nothing to do with the bending of the path of light in the gravitational field. And here’s the kicker – had he actually had even a little bit of an open mind he just might have read the reference to the literature I gave him because this concerned was addressed there. That’s the problem with having such a closed mind. Had Grumpy not be so closed minded then he might have read Ohanian’s text as follows:

    From Gravitation and Spacetime by Hans C. Ohanian, pages 125-129 http://bookos-z1.org/book/451589/a37ce4

    As the author explains the deviation from a straight-line plays no role in the time delay and for that reason the straight path approximation is used. This explains why Grumpy’s heuristic hand waving argument is so wrong. If he instead just assumed that these GRists weren't as stupid as he and everyone constantly assume them to be then you would have learned the nature of your error a long time ago. Ohanian explains on page 125-126
    I’m quite aware that nobody in this forum reads the references to the general relativity literature that’s provided to you for confirmation and that’s why I’ve kill filed all of you who ignore them because I have zero time for such closed-minded people.

    Ohanian also goes on to explain what it means for light to slow down in the gravitational field on the bottom of page 128. But since everyone chooses to ignore what the experts say you’ll have to remain ignorant.

    Enjoy your fancy of ignoring the GR literature. See where it gets you. Lol!!!
     
    Last edited: Dec 19, 2013

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