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Thread: Is it Possible the radio waves move faster than Light?

  1. #1 Is it Possible the radio waves move faster than Light? 
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    http://www.universetoday.com/2007/10...peed-of-light/

    Back in 2007 they thought that photons could travel at different speeds, with high energy Gamma Rays being slower than light. Would that mean that lower spectrum radio waves move faster than light?


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  3. #2 Re: Is it Possible the radio waves move faster than Light? 
    Reptile Dysfunction drowsy turtle's Avatar
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    Quote Originally Posted by Demise_
    http://www.universetoday.com/2007/10/03/high-energy-gamma-rays-go-slower-than-the-speed-of-light/

    Back in 2007 they thought that photons could travel at different speeds, with high energy Gamma Rays being slower than light. Would that mean that lower spectrum radio waves move faster than light?
    No, not really. It seems to show that something is slowing down the gamma rays, or is slowing down all EM waves, but higher frequency waves are slowed more. I can't really think of any accepted theory that would explain this, other than that the photons were emitted at different times to start with, or the calculation of the arrival time of the gamma rays was wrong - They were indirectly detected, by the effects of absorbtion in the atmosphere.


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    Drowsy turtle could indeed be correct, the measurements may have been inaccurate due the reasons he stated. This actually happens quite alot, and some experiments often are not even valid at all, due to uncontrolled variables etc. But hypothetically, if repeated experiments showed that higher frequency EM waves did actually travel slower than lower frequency ones, then the aether could finally make a long awaited comeback! This could be explained through the aether, which would be a non-linear medium.
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  5. #4 Re: Is it Possible the radio waves move faster than Light? 
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    Quote Originally Posted by Demise_
    http://www.universetoday.com/2007/10/03/high-energy-gamma-rays-go-slower-than-the-speed-of-light/

    Back in 2007 they thought that photons could travel at different speeds, with high energy Gamma Rays being slower than light. Would that mean that lower spectrum radio waves move faster than light?
    IF it is true, and that is a big IF, then it means that one of the fundamental assumptions of special relativity is incorect. That is a big deal and it basically means that a big revision in the laws of physics is required. In short it means that we don't know what is going on.

    It the general trend turns out to be that higher energy, shorter wavelength photons travel slower than lower energy, shorter wavlength photons that would have radio waves traveling faster than visible light.

    My personal guess, and it is nothing but a guess, is that something else is going on. It probably has something to do with the times at which the emissions occur. It could have something to do with interactions with interstellar gasses. But basically I don't know either.
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  6. #5 Re: Is it Possible the radio waves move faster than Light? 
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    Quote Originally Posted by DrRocket
    Quote Originally Posted by Demise_
    http://www.universetoday.com/2007/10/03/high-energy-gamma-rays-go-slower-than-the-speed-of-light/

    Back in 2007 they thought that photons could travel at different speeds, with high energy Gamma Rays being slower than light. Would that mean that lower spectrum radio waves move faster than light?
    IF it is true, and that is a big IF, then it means that one of the fundamental assumptions of special relativity is incorect. That is a big deal and it basically means that a big revision in the laws of physics is required. In short it means that we don't know what is going on.
    True, unless it turns out there's a way to unify them. If Aether theory makes a come back, I'm sure it will have to be in some kind of a modified form, because the old form seemed slightly ridiculous on its face.

    If it were discovered that longer wavelengths travel faster than shorter wavelengths, and by the right amounts, I wonder if that would topple the Michealson-Morley experiment? If I'm not mistaken, if we assume the device in the picture is moving in the "rightward" direction, then the portion of the beam that gets reflected in a direction sideways with respect to the motion of the interferometer is red shifted for the duration of the distance it travels before coming back and being reunited with the other part of the beam.

    That is also the one that is expected to have traveled a greater distance, so if it were moving faster than C, that could make up for it.

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  7. #6 Refractive index <1 
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    I heard of materials with refractive index less than 1. That is they allow the propagation of EM waves at speeds greater than c through it. Simillar doubt!
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  8. #7 Re: Is it Possible the radio waves move faster than Light? 
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    Quote Originally Posted by kojax

    If it were discovered that longer wavelengths travel faster than shorter wavelengths, and by the right amounts, I wonder if that would topple the Michealson-Morley experiment? If I'm not mistaken, if we assume the device in the picture is moving in the "rightward" direction, then the portion of the beam that gets reflected in a direction sideways with respect to the motion of the interferometer is red shifted for the duration of the distance it travels before coming back and being reunited with the other part of the beam.

    That is also the one that is expected to have traveled a greater distance, so if it were moving faster than C, that could make up for it.

    Look at the numbers. the gamma rays arrived 4 min late from 500 million ly away. That only works out to a difference of 4.6 microns/sec. The M-M experiment deals with measuring differences of 10s of km/sec, and there would be a much smaller difference in wavelength.

    Or put another way, if light speed varied by 10s of km/sec with such a small wavelength shift, we would have noticed this long ago. We would have been measuring time lags of seconds between the reception of light frequencies from the Sun just over the visible spectrum.
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  9. #8 Re: Is it Possible the radio waves move faster than Light? 
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    Quote Originally Posted by Janus

    Look at the numbers. the gamma rays arrived 4 min late from 500 million ly away. That only works out to a difference of 4.6 microns/sec. The M-M experiment deals with measuring differences of 10s of km/sec, and there would be a much smaller difference in wavelength.

    Or put another way, if light speed varied by 10s of km/sec with such a small wavelength shift, we would have noticed this long ago. We would have been measuring time lags of seconds between the reception of light frequencies from the Sun just over the visible spectrum.
    I totally missed that. Good point. So, there's really no reason to doubt the validity of the results of the experiment the OP is talking about, because the measured effect is so small that it couldn't possibly conflict with any of the existing body of science. At least none of our past observations would conflict with it.
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  10. #9  
    Forum Radioactive Isotope MagiMaster's Avatar
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    This falls under the classical limit. That is, this effect, if it really exists, is small enough that it doesn't invalidate currently known science over some of range of validity. Even Newtonian mechanics wasn't completely invalidated by relativity over a certain range of speeds, etc. (That is, Newtonian mechanics are still very accurate when relative speeds and gravity are kept small.) That's not to say that it wouldn't point to new physics, but even if it exists, you can't completely throw everything else out.

    Also, I'd like to add that this effect would not be consistent with the hypothesis of an aether as a medium for light. The MM experiment is still valid and still shows that light isn't carried by a medium.
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    I should point out a well-known piece of physics that the posters in this thread may not remember:

    The rule that the speed of light = c, while true at the classical scale, is not quite true (or even entirely meaningful) at the quantum scale. Photons can travel all sorts of paths with non-zero probability. It is only "on average" that these paths correspond to the paths predicted by special relativity.

    This observation is not new physics--Feynman made special mention of it in his book QED.

    Of course, without knowing the details of the experiment mentioned in this thread, I can't say for sure whether this is what's going on.
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  12. #11  
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    Quote Originally Posted by salsaonline
    I should point out a well-known piece of physics that the posters in this thread may not remember:

    The rule that the speed of light = c, while true at the classical scale, is not quite true (or even entirely meaningful) at the quantum scale. Photons can travel all sorts of paths with non-zero probability. It is only "on average" that these paths correspond to the paths predicted by special relativity.

    This observation is not new physics--Feynman made special mention of it in his book QED.

    Of course, without knowing the details of the experiment mentioned in this thread, I can't say for sure whether this is what's going on.
    I don't think that is quite what is going on is this case. The experiment is an observation of gamma rays coming from a distant supermassive black hole. There are competing explanations, but one involves "quantum foam", from some quantum theory of gravity. The theoryis not identified in the article but it sounds as though is is one brand or another of loop quantum gravity. Whatever it is, I don't think it is standard QED.

    Apparently the theoretician for this project is Ellis and he predicted a refractive index for the vacuum based on some sort of string model

    http://front.math.ucdavis.edu/search...=25&s=Listings
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  13. #12  
    Forum Ph.D. Steve Miller's Avatar
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    Hello,

    I, in fact, think there can't be faster motion than the one of light. Since, besides mathematics and geometry, light waves are the only measure to apply, at the end.

    Steve
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  14. #13  
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    Quote Originally Posted by Steve Miller
    Hello,

    I in fact think there can't be an faster motion than the one of light. Since, besides mathematics and geometry, light waves are the only measure to apply, at the end.

    Steve
    Huh?

    In any case the question applies to light. The claim is that photons of different frequencies travel at different speeds through a vacuum.
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  15. #14 Re: Is it Possible the radio waves move faster than Light? 
    Forum Ph.D. Steve Miller's Avatar
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    I'm sorry.?

    Quote Originally Posted by Demise_
    Would that mean that lower spectrum radio waves move faster than light?
    Do you understand what I was saying DrRocket? What I was referring to, respectively?

    Steve
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  16. #15 Re: Is it Possible the radio waves move faster than Light? 
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    Quote Originally Posted by Steve Miller
    I'm sorry.?

    Quote Originally Posted by Demise_
    Would that mean that lower spectrum radio waves move faster than light?
    Do you understand what I was saying DrRocket? What I was referring to, respectively?

    Steve
    No. Your statement made no sense.
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  17. #16  
    Forum Ph.D. Steve Miller's Avatar
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    I think it does, nevertheless.

    Steve
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  18. #17  
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    Quote Originally Posted by Steve Miller
    I think it does, nevertheless.

    Steve
    You think what does what ?
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  19. #18  
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    Quote Originally Posted by MagiMaster
    Also, I'd like to add that this effect would not be consistent with the hypothesis of an aether as a medium for light. The MM experiment is still valid and still shows that light isn't carried by a medium.
    What a horrible misunderstanding you have. The MM experiment never proved that light is not carried by a medium.
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  20. #19  
    Forum Ph.D. Steve Miller's Avatar
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    Quote Originally Posted by DrRocket
    Quote Originally Posted by Steve Miller
    I think it does, nevertheless.

    Steve
    You think what does what ?
    I think it does make sense, however.
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  21. #20  
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    Quote Originally Posted by Steve Miller
    Quote Originally Posted by DrRocket
    Quote Originally Posted by Steve Miller
    I think it does, nevertheless.

    Steve
    You think what does what ?
    I think it does make sense, however.
    I am afraid that you do.
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  22. #21  
    Forum Radioactive Isotope MagiMaster's Avatar
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    Quote Originally Posted by Waveman28
    Quote Originally Posted by MagiMaster
    Also, I'd like to add that this effect would not be consistent with the hypothesis of an aether as a medium for light. The MM experiment is still valid and still shows that light isn't carried by a medium.
    What a horrible misunderstanding you have. The MM experiment never proved that light is not carried by a medium.
    What the MM experiment showed is that light travels at the same speed regardless of which direction the Earth was moving. (It was run twice, six months apart. It may have been run more than that, but I don't remember off the top of my head.)

    Therefore, if there was some medium, the Earth would have been moving across it one way for one measure, and the opposite for the other. Since there was no change in the speed, it implies that there was no such medium for it to move across.
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  23. #22  
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    Quote Originally Posted by MagiMaster
    Quote Originally Posted by Waveman28
    Quote Originally Posted by MagiMaster
    Also, I'd like to add that this effect would not be consistent with the hypothesis of an aether as a medium for light. The MM experiment is still valid and still shows that light isn't carried by a medium.
    What a horrible misunderstanding you have. The MM experiment never proved that light is not carried by a medium.
    What the MM experiment showed is that light travels at the same speed regardless of which direction the Earth was moving. (It was run twice, six months apart. It may have been run more than that, but I don't remember off the top of my head.)

    Therefore, if there was some medium, the Earth would have been moving across it one way for one measure, and the opposite for the other. Since there was no change in the speed, it implies that there was no such medium for it to move across.
    What the MM experiment showed is that light travels at the same speed regardless of which direction the Earth was moving. (It was run twice, six months apart. It may have been run more than that, but I don't remember off the top of my head.)

    Therefore, if there was some medium, the Earth would have been moving across it one way for one measure, and the opposite for the other. Since there was no change in the speed, it implies that there was no such medium for it to move across.[/quote]

    Actually what it showed is that if you assume the Galilean transformation between reference frames then there is no aether.

    You can still assume a medium (the aether) IF you also simply assume the Lorentz transformation is the correct transformation. This is a rather ham-handed way to handle the problem and the SR construct which does away with the aether is a simpler and more elegant formulation. In short, since the aether plus Lorentz adds nothing to SR there is no need for the aether. Lacking a purpose, out it goes.

    So as a result of MM and special relativity the aether is left with nothing to do and nothing to explain. For all intents and purposes one can dispense with it and lose nothing. So we do.

    But MM doesnot tell you anything of note regarding potentially small differences as a function of wavelength. And that is the question raised by the observation that started this thread. I am rather doubtful that the observation will stand up to further inquiry, but that will be determined by time and analysis.
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  24. #23  
    Forum Radioactive Isotope MagiMaster's Avatar
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    Oh. Thanks for clearing that up.
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