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How does gravity work?

  1. Mar 7, 2009 #1
    I wont understand anything complex so try to be as simple as possible. If gravity is like putting an object on a blanket, so it makes the object attracted to the center, what pushes on the object to make it go to the object that it is attracted to. (I cant explain what im saying any better. Basically i tried to say what pushes on you.)
     
  2. jcsd
  3. Mar 7, 2009 #2
    edit: disregard. I was mistaken.
     
    Last edited: Mar 7, 2009
  4. Mar 7, 2009 #3

    Nabeshin

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    Nothing pushes anything. The key concept here is that objects want to travel the shortest distance between two points. Like you said, gravity can be thought of as putting an object on a blanket such that it distorts (curves) the blanket. Anything moving nearby follows the shortest path, which is no longer a straight line because the blanket is curved. These shortest lines are called geodesics, and gravity is simply a result of the fact that mass produces curved geodesics.
     
  5. Mar 8, 2009 #4

    A.T.

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    The depressed blanket doesn't explain mass attraction. For better visualizations including time and geodesics follow the links in this post:
    https://www.physicsforums.com/showpost.php?p=2046692&postcount=4
     
  6. Mar 13, 2009 #5
    An object no matter what, moves through space and time (unless your thinking of parallel universes) because that's the way it is. if it does't i have no idea what it moves through because every thing is space and time. so a very massive object (i'm using a massive object because that's when gravity is really effective) like the sun warps this "fabric" of space and time, (you can think of space and time as a 2D fabric like the sheet on a trampoline). so an example would be a bowling ball on the trampoline and when an object like a tennis ball representing the earth moves on this fabric it will move on it even if it curves or "warps" (or else it would be in midair). so if the sun curves spacetime, the earth will move on it because again then it wouldn't be traveling through spacetime. that's how gravity works, and i hope that helps but if not then read a oversimplified version of general relativity. and for the blanket on the object thing that you talked about, what's pushing you or the object is the fact that your traveling through spacetime and if it curves because of a massive object then you should travel through the curved space time which in fact makes you attracted towards the object.
     
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