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Thread: A thought about the Speed of Light

  1. #1 A thought about the Speed of Light 
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    Please verify if this is a valid approach. If not, please explain why.

    As a particle approach the speed of light, its perception of time changes (the "internal clock" slows down).

    Everything travels throught space, but also through time. We could even say that the faster something travels through space, slower it does throught time.

    Can i discribe the particle's own time by the formula: Vt^2 + Vs^2 = c^2 ?

    where:
    Vt = speed in time.
    Vs = speed in space.
    c = speed of light.

    this way, for an object to "age" 2x slower (Vt/2) than a rest particle his Vs should be:

    Vs = sqrt(c^2 - Vt^2)
    Vs = sqrt(c^2 - (c^2)/4)
    Vs = sqrt((3/2)*c^2) = sqrt(3)*c/2


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  3. #2  
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    http://en.wikipedia.org/wiki/Special_relativity

    Look at the discussion under Minkowski space.


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  4. #3  
    Forum Freshman Spaceman's Avatar
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    Hmm, I have heard of an particle that go faster than speed of light, Tachyon particle. But if Tachyon particle's exist i don't kow. Scientist can't find them in the cosmology. But if they exist they should go so fast that the scientist can't see them.

    I think tachyon particle's travel backwards in time (lol, I heard that in a movie lol, Land of the lost).

    But when astronauts come up to space, They ''go'' forward in time becuse they is not affected by gravitation. Earth is affected by gravitation, That is why our clocks goin slower than i space.
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  5. #4  
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    Quote Originally Posted by Spaceman
    Hmm, I have heard of an particle that go faster than speed of light, Tachyon particle. But if Tachyon particle's exist i don't kow. Scientist can't find them in the cosmology. But if they exist they should go so fast that the scientist can't see them.

    I think tachyon particle's travel backwards in time (lol, I heard that in a movie lol, Land of the lost).

    But when astronauts come up to space, They ''go'' forward in time becuse they is not affected by gravitation. Earth is affected by gravitation, That is why our clocks goin slower than i space.
    Tachyons is not more than an idea - a tautology almost. But there have been theoretical speculations that antiparticles are just normal particles travelling back in time.
    http://mindbluff.com/antiparticles.htm
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    Forum Freshman Spaceman's Avatar
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    But if a anti-particle can travel back in time, But if the anti-particle can travel back in time it should break the speed of light?
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    Maybe not. Going faster than light is one form of backwards time travel, there may be many more. Or none at all.
    "If you wish to make an apple pie from scratch, you must first invent the universe". - Carl Sagan
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    Time is merely a man-made measurement of predictable change and Dr Who is merely an SF TV show. There is no going back in time. You can only slow the rate of change down by doing so on a molecular level (heavy gravity) or reducing the energy of particles (speed).

    It is said that photons may have a mass (somewhere below 10^-35 kg). This would solve a number of problems like why gravity bends their paths so doing away with the curved space nonsense. It would also mean that while photons are very fast because they weight almost nothing, that gravity was that bit faster.
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    Quote Originally Posted by Spaceman
    But if a anti-particle can travel back in time, But if the anti-particle can travel back in time it should break the speed of light?
    Why?
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    A photon's rest mass is just an expression of its energy, ie E=MC^2. It does NOT mean that it has mass when stopped because you CANNOT stop it, it only travels at c.
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    Sorry, my mistake for not being explicit. The speed of light IN A VACUUM is C, no more, no less.
    Tricks that pass it through super-cold plasmas where it is absorbed and re-emitted only when the atom is stimulated by a laser don't change the fact that an electromagnetic wave ( or a photon, if you prefer ) only travels at the speed C in a vacuum.

    There is a difference between posting links and reading and understanding them.
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    Excuse me? Why the snotty reply?

    Just because I posted a link, doesn't mean I don't get the difference between the speed of light in a vacuum and propagation through a plasma. I was merely pointing to something I saw that I thought others might find of interest.

    Looks like someone got up on the wrong side of the phuton.
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    My apologies, didn't mean to be snotty.
    I was merely pointing out something that others might find of interest.
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    How fast can matter travel? The LHC is puny by comparison to events in space. We have detected protons with an energy of 3x10^20 electron volts which over a light year would arrive just 47 nanometers behind a photon. But why not still higher energies like particles from a hypernova which may even reach light speed?
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    ask urself what happens when matter enters a black hole. i.e. the event horizon??

    reaches the speed of light? I dont know but if I were to place a bet I would say very likely

    the speed would need to at least equal the speed of light at that point to stop the light from leaving.
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    At or inside the event horizon mass/energy can do whatever it wants, as it no longer has any connection to our universe. A few things are conserved such as charge,and mass/energy, and entropy increases but all other information is lost forever and cannot be extracted.
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  18. #17  
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    Quote Originally Posted by MigL
    At or inside the event horizon mass/energy can do whatever it wants, as it no longer has any connection to our universe. A few things are conserved such as charge,and mass/energy, and entropy increases but all other information is lost forever and cannot be extracted.
    Do u have some sources to back up statements like that?

    All I was saying was that at the event horizon light technically stops or reverses, inside the event horizon no one knows what happens but that doesn't mean "mass/energy can do whatever it wants"

    As for information loss thats also debatable we simply dont know what happens in the event horizon, and anyone that does "know" is probably just making a guess.
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    There are well devloped theories of black holes from the like of Oppenheimer, Wheeler, Hawking and Thorne ( I recommend Kip Thorne's book on gravity and black holes ). These theories are all consistant with Einstein's General Relativity. So, yes, we have a pretty good idea as to what happens at the event horizon of a black hole.

    The math backs them up. What backs up your opinions ??
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  20. #19  
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    Quote Originally Posted by MigL
    There are well devloped theories of black holes from the like of Oppenheimer, Wheeler, Hawking and Thorne ( I recommend Kip Thorne's book on gravity and black holes ). These theories are all consistant with Einstein's General Relativity. So, yes, we have a pretty good idea as to what happens at the event horizon of a black hole.

    The math backs them up. What backs up your opinions ??
    I wasn't disputing that we know what matter/ energy does at the event horizon there is a lot of research on this and u have mentioned that clearly I was talking about ur comment where u say at or IN the event horizon and its the IN part that I wanted to discuss, Im not aware of theory's that state matter can do what it likes inside a black hole because again just as far as Im aware all our maths fails at that point (something very small and very strong gravity) general relativity meets quantum mechanics.

    But Im no expert so I was just curious about the inside a black hole stuff, wanted to read more on that, so was asking if I could be given something to read about that

    I hope u didnt take my comment as negative, wasnt meant to come out that way.
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  21. #20  
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    Quote Originally Posted by Always.Asking

    Im not aware of theory's that state matter can do what it likes inside a black hole because again just as far as Im aware all our maths fails at that point (something very small and very strong gravity) general relativity meets quantum mechanics.
    It is only at the center or singularity of the Black Hole where the math fails. In the region between the singularity and the event horizon it still works fine.
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  22. #21  
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    Quote Originally Posted by Janus
    Im not aware of theory's that state matter can do what it likes inside a black hole because again just as far as Im aware all our maths fails at that point (something very small and very strong gravity) general relativity meets quantum mechanics.
    It is only at the center or singularity of the Black Hole where the math fails. In the region between the singularity and the event horizon it still works fine.[/quote]

    Thanks for the Clarification Janus
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