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Race across the Universe:Who is on edge? Force Vs. Light

  1. Sep 23, 2012 #1
    Hey there guys,
    I remembered one stormy night while playing Atari racing game with my son..he asked me: "what is faster force of light?" I escaped with a reply .. "flash first..thunder later" .Suddenly the power was out. My kid went to fetch the flashlight and said to me.."look! push first ..flash later". I know those were naive notions, but seriously today i am certain there is an answer.
    Who's winning?
    thanks
     
  2. jcsd
  3. Sep 23, 2012 #2
    What do you mean by "speed of force?" Do you mean that you shove on one end of an object and count how long it will take for the other end to feel the force?

    I'm pretty sure it'll move at the speed of sound under that definition, which is nowhere close to the speed of light.
     
  4. Sep 23, 2012 #3
    In short, nothing travels faster than the speed of light.
    Chris
     
  5. Sep 23, 2012 #4
    Its like..what if the light journey is being affected by gravity (or curvature?) along the way.. classic sample is the rabbit-turtle race where the rabbit being confident have napped himself to perdition.
     
  6. Sep 23, 2012 #5

    phinds

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    What is your point? What part of "nothing travels faster than light" do you not understand?
     
  7. Sep 23, 2012 #6

    mfb

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    "nothing travels faster than light" in vacuum.
    In water, for example, electrons can easily travel faster than light. This gives the blue glow in nuclear reactors (cherenkov radiation).
    If you care about the total time from A to B, you can also consider a mirror system for light.

    Anyway, your question is quite unclear.
     
  8. Sep 23, 2012 #7
    I think the question is, "Which is faster, force or light?" Force doesn't really have a speed because it is not a thing, but an effect. However, force does have a speed of propagation, which depends on which force you are talking about. The force of gravity propagates at the speed of light. The force of electromagnetism propagates at the speed of light because propagating electromagnetic waves _is_ light. I think the strong force and weak force both propagate at slower than the speed of light because their associated bosons are massive.
     
  9. Sep 23, 2012 #8
    Yeah, i mistook that speed comparison is the same as which ever is ahead on the edge of the Universe is faster.. i was tipped that the "speed of force" = c , the only difference therefore is which (light or force) have the head start, but since the light some how can be held back by force (GR) ,it would result to something else.. well thank you for reply

    Rephrasing the Query : What is it there at the very boundary of our Universe? What we ought to feel gravity or radiation?
     
    Last edited: Sep 23, 2012
  10. Sep 23, 2012 #9
    There is no boundary to the universe, as far as we know. Either the universe is infinitely large, or the universe wraps around on itself. The universe did not start as a point.
     
  11. Sep 23, 2012 #10
    The SPACE is confirmed flat and open..but Universe is not Space
     
  12. Sep 23, 2012 #11
    They are sort of one and the same, think about it for a while.

    I don't understand your point/question though.
     
  13. Sep 23, 2012 #12
    well..i don't like research work. i guess it will really take a while
    I just try the similar threads below.
    Thanks again
     
    Last edited: Sep 23, 2012
  14. Sep 24, 2012 #13

    mfb

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    Gluons (bosons of the strong interaction) are massless.

    "Speed of a force" is simply not well-defined - a force is not an object.
    "Speed of propagation of gravitational influence" is the speed of light.
     
  15. Sep 26, 2012 #14
    If you're interested in astrophysics but you don't like "research work", you might want to browse through Wikipedia articles about the universe and space. They're usually suited for the general public and it would probably be less chaotic than sifting through random posts in the Phycics Forums.

    Chris
     
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