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Speed of gravity = c

  1. Apr 10, 2003 #1


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    it has been reported that the speed of gravity = c does this mean that an object traveling at c would not feel the efects of gravity?
    Last edited by a moderator: Feb 4, 2013
  2. jcsd
  3. Apr 10, 2003 #2


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    Staff: Mentor

    Re: gravity

    Well... since an object can't travel at C, its kinda a pointless question. LIGHT however, travels at C and is affected by gravity (or rather the curvature of space that gravity creates).
  4. Apr 11, 2003 #3


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    Right, the path of a photon is affected when it travels through an area of space-time that has already been curved by gravity.

    However, if a photon were to pass through a relatively "flat" area of space-time and, after it had passed, a massive object (such as a planet) suddenly materialized in that space, the gravity from that planet would (theoretically) never effect that photon. The sudden appearance of the planet would send a huge gravity wave out in all directions, this wave would propagate at lightspeed, and never "catch up" to anything traveling at lightspeed the had already passed.
  5. Apr 12, 2003 #4


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    Re: gravity

    Greetings !
    I believe the current proven possible range
    was reported to be something like 0.8 - 1.05 c.
    (This could be outdated or slightly inaccurate info.)
    More accurate tests are still required to
    make sure that reality "follows" the laws of theory.

    As for the question - since no particle with rest
    mass can reach c, it is somewhat pointless to ask
    "What if... ?" about this.

    Live long and prosper.
    Last edited: Apr 12, 2003
  6. Apr 16, 2003 #5
    Wouldn't it make sense that gravity would also travel at the speed of light, as it seems more then unlikely it would travel at 1.05c, and as you stated, it has zero rest mass. Those figures seem to ring a bell of a recent experiment done by Sergei Kopeikin in which they, supposedly, measured the speed of gravity by measuring how much "wobble" was in Quasar JO842+1835 as it passed by Jupiter. Upon review by peers, it was reported they simply found a new way to measure light, not actually the speed at which gravity affects space.

    Some would have also said it was pointless to ask "What if...there was no ether.":wink:

    If nobody asks, then nobody learns!
    Last edited: Apr 16, 2003
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