# Gravity Field

1. Aug 9, 2004

### The Green Giant

Hi,

I was wondering if in the middle of the earth (the VERY) center, there would be a spot that had no gravity, that would be like space,where if you were the right size you would be weightless. PLZ HELP!!! THX!

2. Aug 10, 2004

### blackflub

no matter where you are in the earth there will be the force of gravity. theoretically if you were in the complete center of the earth the forces of gravity would cancel themselves out, but this is untrue being the earth isn't a perfect sphere and isn't composed of the same materials throughout. also the fact that on the surface of the earth objects are always moving means that a point at which no gravity exist would be impossible to find. there is a possibility of such said point to exist on a very small level but the amout of time that it would exist would make use of it totally useless.

3. Aug 10, 2004

### marlon

Even when you look at atomic scale gravity is there. It just is extremely little that it was originally ignored in the standard model...

4. Aug 10, 2004

### Gonzolo

I think that yes, there is a region where gravity cancels out, and that if it wasn't so hot and dense, someone could float around in there. Movements on the surface of the earth would be too far away to matter. And while mass distribution in the earth isn't perfectly uniform, I think the nonuniformity is mostly on the surface, which is relatively thin, and would only result in a real slight offset between the gravitationnal and geometrical centers. I imagine though, that someone would feel an odd, but bearable sensation of our body wanting to "stretch" slightly in all direction, since there would be a sizeable fraction of g in all directions.

Last edited by a moderator: Aug 10, 2004
5. Aug 10, 2004

### dlgoff

6. Aug 11, 2004

DID EVERYBODY forget about the SUN and The MOON. if you are at the centre, even if all gravity cancels out, the force of the sun is still pullin on you and the force of the moon.

7. Aug 11, 2004

### Gonzolo

True, but you would still experience weightlessness.

8. Sep 3, 2004

### ComputerPsi

Lets solve this mathematically..

Acceleration due to gravity inside the Earth:
g' = ( r / re )g

r represents the radius of the point inside
re represents the radius of the earth

So, if we are in the center of the earth...

g' = (0/6378000)*9.81

g' = 0

So, theoretically, there is no gravity.

Note - This is only if no other force of gravity is added.