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Thread: Faster than Light data possible??

  1. #1 Faster Than Light Data Streams? 
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    Hi,

    I read that using Plasmas, the phase velocity of an em wave can be increased instead of decreased as in normal materials.

    http://www.rmcybernetics.com/science..._materials.htm

    Does this mean that you could send data faster than the speed of light? Or does this defy special relativity?

    Cheers,
    DaveyJones


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  3. #2  
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    You can't go faster than the speed of light in the medium.

    But the speed of light does vary with the refractive index of the medium the light is traveling through.

    n = c / v where n = ref index of the medium, c = speed of light in a vacuum, v = speed of light in that medium

    In a vacuum, n=1. For air, n = 1.0004

    It is possible to have materials with n <1 for certain wavelengths, through a phenomena known as anomalous dispersion. In this case, if n = 0.5 for certain wavelengths, then light of that wavelength travels through that material faster than it would in a vacuum. Unfortunately, materials with n<1 are not transparent, so the light doesn't travel very far!

    Here are some good articles to read:
    Theory of refraction: http://theory.uwinnipeg.ca/physics/light/node5.html

    Theory of dispersion, with some discussion of 'apparent' possibility of superluminal communication: http://en.wikipedia.org/wiki/Dispersion_
    (optics)

    Discussion from PhysicsWorld of how nothing goes faster than light: http://physicsweb.org/articles/world/13/9/3

    If you get real curious, google "negative refractive index". There are some very interesting developments in this concept in the last decade, with strange results.


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  4. #3  
    Forum Professor wallaby's Avatar
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    well if its over short distances wouldn't the message be recieved before it is sent.
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  5. #4 Re: Faster than Light data possible?? 
    Forum Radioactive Isotope mitchellmckain's Avatar
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    Quote Originally Posted by daveyjones
    Hi,

    I read that using Plasmas, the phase velocity of an em wave can be increased instead of decreased as in normal materials.

    http://www.rmcybernetics.com/science..._materials.htm

    Does this mean that you could send data faster than the speed of light? Or does this defy special relativity?

    Cheers,
    DaveyJones
    This is periodically challenged by new phenomena like this all the time. The possibility that it could be faster than light is discussed only because it creates a sensation in the media and gets people to pay attention. But when other scientists check up on this possibility they invariably find that the information travels less than the speed of light.

    Here is an example which was discussed in a thread under "Astronomy and Cosmology".
    www.npl.washington.edu/av/altfw75.html
    See my physics of spaceflight simulator at http://www.relspace.astahost.com

    I now have a blog too: http://astahost.blogspot.com/
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