This might sound like a stupid question..but first, two basic definitions for gravity:

The natural force of attraction exerted by a celestial body, such as Earth, upon objects at or near its surface, tending to draw them toward the center of the body.

The natural force of attraction between any two massive bodies, which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.


My question is: How is it that there is a planet, when in fact the gravity needed to draw that which would make up the planet to the planet wouldn't exist until after the planet reached a substantial amount of size?

Pretty much: How the hell did gravity even get going in the first place?

there are quiet a few physics lectures that explain just this...


i suggest you go watch them.

Lectures put me to sleep.

meh... sometimes it takes effort to learn.

gravity is a property of matter. when matter began clumping together, more gravity formed, grabbing more stuff. it bundles up until you get a force that actually matters.

...but people, such as myself, are made of matter.
Wouldn't the matter then continually clump and clump and make me all freakishly bloated in some odd manner by matter drawn to me?
Or would that process take far too much time for anything to really happen during my life?

no, a much greater force of gravity has control in it's sphere, thus all the stuff goes down.

Get ready for some shut eye! First of all the Newtonian account for gravity has since been discounted in favor of the general theory of relitivity model (newton still works great stuff like bullets baseballs and rocket ships beacuse the differences bettween newtons equations and enistines are so miniscule that any oserable difference only happens with super massive objects like Rossane Barr or at near light speed)

Next gravity happens to be the weakest of all the forces by far (an example would be holding your hair with a charged ballon) and thus is easily overcome in most contex by weak, strong (the necular forces) electromagnetic forces this should explain why things dont crumple into solid matter on account of gravity.

so how did gravity start well heres a bit of a let down but noone realy knows. gravity despite being the weakest of all the forces is the least understood. for every force we have found an associated "carrier" particle that transmits the force (i appoligise if this is sounding a bit too star wars force this and force that) we have found no such particle for gravity. A leading theory in physics gauge field symetry basicly elementary particles can be placed into groups of 5, 8 or 10 and these groups exibit reflectionial symetry in this way it has been hypothized that at early cosomologcial stages (very early) that the forces were united into one force and as the universe cooled down these forces scmetercialy split thus becoming the phenomon we observe currently as proof that this is possible the equations governing weak and electromagnetic force could be combined into one force the electroweak force in a universe at a sufficent tempature even earlier strong can be combined with the electroweak force. one would reason that this trend could continue and combine all the forces but due to our fundmental lack of knowlage of gravity this has not been accomplished. the best anwser to your question is that gravity is a feature of our universe an offspring or conquence of what happened very early in the universe. if this does not satisfy your anwser i will take the scientific copout approuch that the universe wouldent exist if gravity dident exist and therefore it must exist (leaves a lot to be desired dosent it).

gravity comes from the density of the core, which is the result of the pressure pushing down on it, which is a result of the mass.......for example, a star first starts out as a stellar cloud, a mixture of dust and gas swirling around in space.........after awhile, this shit heats up, begins to spin, forming magnetic fields, and essentially gravity comes into play......as a star gets hotter, brighter, bigger, and what not, its gravity increases as well...........

I think you just made this up. Gravity doesn't have anything to do with density, only mass. If something is twice the size but half the density (therefore the same mass) then it will exert the same pull on something that is the same distance from the centre of mass (assuming the object that you're attracting is outside the perimeter of each).

The thing is that everything, even the smallest speck of sand, exerts a gravitational pull. It's just very weak. So, a cloud of dust, even if it isn't all joined up, will, on anything outside it, exert a pull identical to the pull it would exert if it was all clumped together already.

The universe things did come together extremely slowly. The earth is about 5 billion years old I think, and the universe is about 13 billion (I think). So that's about 8 billion years for the earth to form. Given that everything exerts a gravitational pull it is inevitable that things will clump together eventually, unless matter was distributed evenly and uniformly in a universe without boundaries, which it wasn't.

Things are still clumping together. Though the universe is expanding overall, stars and galaxies in local clusters are often in a process of moving together.

Your second definition for gravity is correct, but 'massive' doesn't mean 'very large,' it means 'with mass.' So any object with mass exerts gravity.

I suppose if we can't really define 'gravity' we wouldn't have a clue about the 'anti'.

And here I was thinking gravity was akin to density. It seemed more logical then, now I'm once again discombobbled.

damn! and here i thought i was being helpful! anyway, i dunno....thatz what i'm learning in physics, but what the fuck do i know about science? besides, i'm kinda struggling in the class....and i didn't make it up, thatz just how i understand my fucking foreign/India/tortured-by-her-husband professor......i had the general idea.........

No, she's wrong if she's been telling you that. Everything exerts gravity in exact proportion to its mass, and it decreases as you move away from the centre of gravity. It doesn't matter where all the actual mass is located, or how densely together it is.

Interestingly, if the earth was a perfectly round hollow shell with an even crust, then anything inside wouldn't be effected by the gravity of the shell at all, as it would all add up to 0.