jump to last post 1-9 of 9 discussions (18 posts)

What is the “speed” of gravity?

  1. flysky profile image82
    flyskyposted 3 years ago

    What is the “speed” of gravity?

    Hypothetically, if one remove the Sun from its place, when the Earth would be affected? Momentary, by the speed of light or by some speed specific to the gravity...?

  2. one2get2no profile image82
    one2get2noposted 3 years ago

    I'm no physicist but O would imagine that the earth would be affected within 8 seconds. We would all be dead.

  3. point2make profile image80
    point2makeposted 3 years ago

    Actually the speed of light would be involved here. At 186,000 miles per second it would take approx. 8 1/2 minutes, not seconds, for you to notice the Sun was gone. Gravity does not have a specific speed per se. It is one of the fundamental forces of the Universe and while the "force" of gravity can be measured...the source of that "force" is an ongoing challenge for science.

    1. one2get2no profile image82
      one2get2noposted 3 years agoin reply to this

      Yes sorry I did mean 8 Minutes and not seconds. A senior moment I'm afraid.

  4. billgaede profile image75
    billgaedeposted 3 years ago
    1. billgaede profile image75
      billgaedeposted 3 years agoin reply to this

      Gravity is not a force. Gravity is a tension, and tension is NOT a force. Stretch a rubber band and hold. Feel the tension. There is no motion. If someone cuts the rubber band, the tension HAD BETTER disappear INSTANTANEOUSLY! It won't take 8 mins!

  5. profile image0
    Daveadamposted 3 years ago

    Gravity doesn't exist it's just logic, logically things have to fall down otherwise what would happen?lol.

  6. tsmog profile image82
    tsmogposted 3 years ago

    I am no physicists or mathematician, however is not the sun already being removed from 'its place' and it is a constant. The sun does rotate and travels within its galaxy . . . the earth's galaxy too. If the sun simply ceased to exist for the thought exercise then we must first define existence.

    1. billgaede profile image75
      billgaedeposted 3 years agoin reply to this
    2. tsmog profile image82
      tsmogposted 3 years agoin reply to this

      So, then there is not matter unless existence. In the case the sun becomes non-existent then the  laws of physics would not apply as there would not be anything to act upon, unless something remained?

  7. samanthajohnes profile image58
    samanthajohnesposted 3 years ago

    Speed of gravity equals the speed of light.  Earth would flight in straigh path as soon as you see the sun disappear, but not sooner.

    1. point2make profile image80
      point2makeposted 3 years agoin reply to this

      Actually the speed of gravity is unknown. We are working hard to assign a value to "gravity" but it has proven elusive to all attempts. We just don't know enough, with our current physics, to solve the "mystery" of gravity.....yet!

  8. arksys profile image92
    arksysposted 3 years ago

    from what i understand, if you move the sun the earth will also move at the same time, because there is a gravitational force between the planets.

    the word you are looking for is "Universal Gravitation" or "Gravitational Constant".

    1. flysky profile image82
      flyskyposted 3 years agoin reply to this

      I am not sure that the Earth will also move at the same time, as you say. It is reasonable to expect that it would be almost at the same time, but I am not sure if we can say so precisely. I think that this is an open problem in physics...

    2. arksys profile image92
      arksysposted 3 years agoin reply to this

      flysky : it is an assumption of course... but the reason i said it would move right away is because the size of the sun in proportion to the earth... I was thinking of the concept of magnetism while stating my assumption. A little delay : yes.

    3. billgaede profile image75
      billgaedeposted 3 years agoin reply to this

      We make an assumption: all atoms are interconnected. There is permanent tension b/w the Sun and the Earth and b/w the Earth and you. We call this tension ‘gravity’. We make the Sun disappear. The Earth HAD BETTER fly away INSTANTANEOUSLY!

    4. arksys profile image92
      arksysposted 3 years agoin reply to this

      Agreed.

  9. John Parks profile image69
    John Parksposted 3 years ago

    There is no proper theory of the speed of gravity, relativity tells us that gravity curves space and time in the presence of mass.  It does not tell us the speed.  If you look at a star, you see it as it was however long ago in time it took the light to travel to your eye.  I believe gravity propagates at infinite speed.  If the suns' gravity took time to travel, then it would influence our orbit at a point, distant from its actual position in space, and would tend to accelerate the earth's orbital speed.  Since we do not see acceleration happening, then it stands to reason that gravities' speed is much faster than light, even though Einstein said light was the upper speed limit.

    Look at the interaction of the Sun-Earth-Moon.  The moon's orbit around the earth is an ellipse which is distorted by the Sun's gravitation. Observations by astronomers have shown that the Sun's force comes from its' true position rather than it's visual position, to a precision of one arc second.  This observation alone, indicates that the speed of the Sun's gravitational force must be many times the speed of light.

 
working