Neutrinos faster than the speed of light?

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

  1. paddoboy Valued Senior Member

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    Correct......But if some of that light/photons, is emitted exactly radially away from the EH, it will appear to hover there, never getting away and never getting sucked in, in that same local FoR, as space/time is also falling the other way, towards the Singularity at exactly "c".


    Photons do not orbit in circles at the horizon, just skimming the surface. The place where photons orbit in circles is the photon sphere, at 1.5 Schwarzschild radii. Photons emitted at the horizon fall in; except that if a photon is emitted exactly vertically outward exactly at the horizon, then it will hover at the horizon, not moving at all.
    http://casa.colorado.edu/~ajsh/singularity.html#r=1

    Scientific theories are never proven. Part of the scientific methodology is that further observations, better experiments, more precise measurments may perhaps modify or change what we actually believe. eg: We could use SR/GR to calculate/measure Earth related scenarios where we would normally use Newtonian mechanics, and we would get the same answer, just with more precision.
     
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  3. paddoboy Valued Senior Member

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  5. river

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  7. exchemist Valued Senior Member

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    I URGE READERS NOT TO REACT TO THIS. If you do, it will not be at all illuminating, for any of us, I guarantee.
     
  8. river

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    of course the " illuminating " thing is what you want to believe
     
  9. brucep Valued Senior Member

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    I'm sick and tired of your illiterate trolling nonsense. That is a fact not a belief. I imagine exchemist feels somewhat the same way about you as I do. Hopefully the moderation will come to the conclusion that 'river' trolling needs to move on new pastures. Your feet stink like 'dumbshit'.
     
  10. OnlyMe Valued Senior Member

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    Paddoboy, my intent was not to be adding to the discussion, at times debate, concerning the theoretical aspects of black holes and event horizons. Initially all was was attempting to do was point out that theory and fact were getting mixed up in the discussion. It just happened that Grumpy's post was the one that I focused on, nothing specific to his point of view was the catalyst. I had started to post several times earlier and then just let it go.

    The above is thrown about way too often in discussions such as this. While it is true it adds little to the discussion. Think about it for a moment... Time dilation was a theoretical component of both SR and GR before it was demonstrated to occur in reality. Light bending around a strong gravitational field is another example of theory becoming reality, a part of our understanding of the world that was once believed to be, that became something that DOES occur. And yes both remain proven components of the larger theory which predicted them.

    It is fairly certain at this time that black holes and their associated event horizons do in fact occur in reality. I believe that without anyone ever actually seeing either. Knowing the reality of the mechanics of both is far less certain.

    Let me give an example, and take this only as an example, not as any part of any real theoretical solution.... Assume that given a sufficiently large mass in a sufficiently small volume the gravitational "force" is such that atomic structure and dynamics as we know them do not occur. In that case the event horizon would be the point where photons are no longer created. No light to escape. From where we are it would look the same as what we now believe black holes to be.

    Lots of very bright people are working on trying to figure the realities of black hole mechanics and gravity itself out... And they don't all agree.

    BTW just as Peter was glad to see your analogy post, so was I. From my perspective you introduced one of the things, very simply in that post, that had been bothering me about the discussion.

    For anyone trying to, as a lay person get a grasp on what black holes and event horizons are, from the perspective of GR, these are or can be very productive discussions. The problem that seems to come up all to often, from where I sit, is that the discussions almost always slip into aspects of black holes and event horizons that are within the domain of QM.... and QM and GR don't get along well... Neither leads to an understanding of the other.
     
  11. river

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    all I asked pad was does he understand what the sites are saying

    whats the problem
     
  12. paddoboy Valued Senior Member

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    Point taken.....As a layman though, I was not in any way belittling the notion of "theories", as you say, sometimes they are eventually realised as fact.
    The other point re photons emitted at the EH, I just thought didn't appear clear enough.
    Your point re a sufficiently large mass into a sufficiently small enough volume is one I mention a lot, when we get some doubt about a BH's existance and possibilities. And that was realised in the late 1700's!

    Finally my apologies to all for engaging the troll as much as I do.
    It's just that I would like to short circuit as much as possible, the nonsense regurgitated by said troll, that youngins coming here might latch onto.
    It's a fact that forums like this are the trolls/pseudoscience pushers, only outlet....a shame and an annoyance for the rest of us.
     
  13. brucep Valued Senior Member

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    You're the problem. This isn't an isolated event river. These nonsense challenges are trolling. You're not adding anything to the conversation. Trolling is subtraction by addition. Your contribution to this forum is trolling. Subtraction by addition. Less than 0.
     
  14. river

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    so the question of understanding , the challenge ..of , understanding , is a problem ....?
     
  15. brucep Valued Senior Member

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    Your doing fine. Since very few use their real name when surfing the internet, accountability becomes strictly a personal job. You either make yourself accountable or you don't. The internet is an arena for intellectually dishonest sociopaths to show their ass. Another bullshit occurrence is your 'need' to apologize for posting in the forum just because a nitwit sociopathic troll 'needs' correcting. Essentially that's what most of these science threads turn into. Unfortunately.
     
  16. river

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    so you are uncomfortable with being questioned ....
     
  17. pmb Banned Banned

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    I took one of the staples of modern GR textbooks and quoted it verbatim and it stated exactly what I've been teaching everyone here. I found an earlier edition of the text online so any serious student of GR can learn this and know that the misinformation that is being spread in this thread is wrong. It's also a perfect example of the claim that all treatments of GR carry out all measurements in locally inertial frames is, in general, wrong. It’s was understandable to make such a mistake until the facts are made clear. After that there's no excuse/ This text is such an example of working in non-inertial frames. It's required when the integrations are over large regions of a curved spacetime. One of the reasons that Taylor and Wheeler can get away with it in their text is that they don't integrate this over large regions of curved spacetime.

    From Gravitation and Spacetime by Hans C. Ohanian (1976). From top of page 127
    (Download copy to read at http://bookos-z1.org/book/451589/a37ce4)
    I thought I’d post even more examples of the fact that the speed of light changes in a gravitational field so as to demonstrate how universally known this fact is in the GR community. I wanted give a nearly exhaustive list of examples.

    From Relativity; Special, General and Cosmological – Second Ed. by Wolfgang Rindler, (2006), page 191 (Downloadable at http://bookos-z1.org/book/931043/b4e4bd)
    From Basic Relativity by Richard A. Mould, (1994), page 238
    From Was Einstein Right? by Clifford M. Will (1993) (downloadable at http://bookos-z1.org/book/2036789/7dd4d7) – This is about the experimental evidence of the slowing down of light in a gravitational field! Evidence that Grumpy is not ready to admit exists!

    Please Register or Log in to view the hidden image!



    From Exploring Black Holes by Taylor and Wheeler (downloadable at http://bookos-z1.org/book/541224/41cf28) page E-1 to E-2
    This is yet another example where brucep is wrong, i.e. he thought that all calculations in this text are made in locally inertial frames. This is a perfect counter example.

    So there you have it folks. Five examples from the most respected general relativity textbooks on the market today all saying the exact same thing- The speed of light depends on the gravitational field when its moving in a gravitational field Light slows down when it en, some even including Shapiro’s experimental evidence of the slowing of electromagnetic waves in the gravitational field of the Sun. And let’s not forget Einstein’s own calculation and predictions of all of this. Einstein’s theory withstood the test of both time and experiment!

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    For those of you who have yet to make the connection, the reason that the speed of light slows down as it moves through a gravitational field is in part due to the fact that time slows down in a gravitational field and that slowing of time ends up translating to the speed slowing. That in turn is related to the time lag in light signals passing through the Sun's gravitational field. So time dilation is key to understanding the slowing of light in a gravitational field. This is why the radar echos off Mercury were delayed. These are not seperate phenomena, they are the same phenomena.

    So, there you all have it. A demonstration of what many very well known GR experts says on this topic from the heart of the GR literature have to say on this fact (as that term is used to refer to theorems).

    That's all I have to say on this since nobody is willing to provide proof of their claims rather than simply repeating their claims. If so I'll only know of them if you send them to me in a PM.
     
    Last edited: Dec 3, 2013
  18. brucep Valued Senior Member

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    As observed from a remote frame dependent coordinate system. Locally the speed of light = c. That's what all observers agree on after making the transformer from remote coordinates to local coordinates. The local direct measurement is an invariant. Ohanian knows that pete. They can get away with it because it's called physics. The 'real area' that represents the local tangent space on the Riemannian manifold isn't infinite so the integration will tell you 'how big' the local region of spacetime that approximates flat spacetime. There's no limit on the boundary beyond meeting whatever limit you set for your experiment. You haven't actually read Taylor and Wheelers Exploring Black Holes. That's what I have to conclude. Enough said from me. One more thing: Taylor and Wheeler 'get away with it' because they know what the mathematical model predicts.
     
  19. paddoboy Valued Senior Member

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    Not half as uncomfortable as you with mainstream science, obviously.
     
  20. pmb Banned Banned

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    Is he merely asking you questions or is he interrogating you? One is fine while the other obnoxious and should be ignored. And of course it all depends on the spirit in which the questions are being asked too.
     
  21. pmb Banned Banned

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    Good news. While I know that the speed of light slows down in a gravitational field I was shocked to see how few people are able to understand this elemenrtary fact by confusing it with local measurements made in locally inertial frames. I've therefore made arrangements to meet with and interview Irwin Shapiro, the man who led the team who did the experimental work to measure the time delay of radar echos off of Venus and Mars which proved that light does slow down in a gravitational field. I have a company which will in the future have a website for such questions. I'll post it there after I interview him.
     
  22. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    pmb'

    Good, maybe he can explain to you that although gravity does slow down time, it has no effect on the speed of light. Gravity can redshift lights spectrum, or curve the spacetime the light is travelling through, but it never effects it's speed through spacetime in a vacuum no matter what the frame or the relationship of frames.

    Post a single observation of slow light, just one. I won't be bothering to wait because it has never been observed. Shapiro observed TIME dilation, not lightspeed reduction.

    Grumpy

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  23. OnlyMe Valued Senior Member

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    Grumpy, they were measuring the round trip time of light, using a clock stationary in the "lab" frame. The clock was not time dilated.

    What they proved is that the round trip time of light into and back out of the sun's gravity well is not equal to the value of c in vacuum, as measured in the laboratory and an essentially flat or uniform gravitational field.

    The speed of light can be measured locally to be a constant and yet be variable on a macroscopic or cosmological scale. This is perhaps one of the more difficult conceptual transitions moving from SR to GR.
     

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