o_o? why would it have a pull

That is a fundamental force by which objects with mass interact. Objects dont really "have gravity", rather they exert a force on each other. That is Newtonian gravitation, in theory of relativity, gravitation is a geometric property, meaning that there is no force of gravity, instead objects with mass cause the curvature of space. You can't really answer why because this is the most fundamental question and we don't even know the nature of gravitation.

actually all masses have gravity -- just the bigger they are the more appreciable the effect gets. So far, according to Einstein, gravity is explained by the fact that masses curve space -- so imagine a really plushy bed, and you put a basketball on it -- what happens when you roll a small marble tangent to the basketball? It'll start revolving around it (well, if it kept going it would travel like so). Thats pretty much a crude explanation of gravity.

i think thats more used to describe how timespace is warped by large groups of dense matter.

uhm...thats exactly what gravity is (according to relativity)

i lold

that's not the question. also is gravity instantaneous or what whats the deal. why would a big object instantaneously pull stuff to it

Uhm I just explained why it would have a pull (its technically not a pull) - - as far as your question is concerned, you asked why objects are attracted to each other, and I simply said it was the curvature of space that explained this 'attraction'.... Also what does instantaneously mean? Gravity works the moment that object comes into existence, and then pulls with a certain acceleration and eventually the object that it is pulling will get faster and faster... the further away the object is from the gravitational center, the less of an initial 'pull' it has...and technically it will never have an acceleration of 0, it will just be infinitely miniscule at extreme distances.

gravity isn't an "instantanous force"


if the sun were to disappear, you would have a ripple effect of spacetime@ the speed of light. so we wouldn't experience it being gone until after 8 minutes.

i think

This post was edited by 011011100101110111 on Jan 20 2009 07:05pm

that matter simply cant disappear (strictly against the rules), so this example is null.