Pull of Gravity.Where it starts?

  1. Pull of Gravity.......Where it starts?

    hi...

    Juz curious... when does the gravitational pull of earth starts?

    eg:
    Let's say a comet/ a space rock ...It will travel slowly in space but once it is caught by gravity, it will accelerate, right? Yeah... so when does that happen.What distance from earth will the earth's gravitational force starts to act on the subject.
     
  2. jcsd
  3. Infinitely far away, because the force between the bodies is GMm/(r*r). If your question was meant to be when the force between Earth and the comet is the dominant gravitational force, well that's an entirely different question.
     
  4. Chronos

    Chronos 9,786
    Science Advisor
    Gold Member

    Well, technically, the affect of earths gravity field is only observable out to a distance of about 2.75 billion light years.
     
  5. Would quantum mechanics dictate a zero-point minimum gravity? Does the graviton have a minimum energy level so that there is a mimimum gravity force?
     
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