Is there a Gravity-Free Spot at Earth's Center?

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Discussion Overview

The discussion revolves around the concept of gravity at the center of the Earth, specifically whether a point exists where gravity is effectively zero, akin to a weightless environment in space. Participants explore theoretical implications, physical principles, and the effects of Earth's structure on gravitational forces.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions if a gravity-free spot exists at the Earth's center, suggesting it would be similar to space.
  • Another participant argues that gravity is present everywhere within the Earth, noting that while forces may cancel at the center, the Earth's non-uniformity and surface movements complicate this idea.
  • A different viewpoint suggests that a region where gravity cancels out could exist, but acknowledges the effects of temperature and density, as well as the potential for a sensation of stretching due to gravitational forces in all directions.
  • One participant emphasizes that external gravitational influences, such as those from the Sun and Moon, would still affect a person at the center, even if local gravity cancels out.
  • A mathematical approach is presented, calculating that theoretically, gravity at the center of the Earth could be zero, assuming no other gravitational forces are acting on the point.

Areas of Agreement / Disagreement

Participants express differing views on the existence of a gravity-free point at the Earth's center. Some argue for its theoretical possibility, while others contend that gravity is always present due to various factors. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Participants note the Earth's non-uniform mass distribution and surface movements as factors that complicate the concept of a gravity-free point. The discussion also touches on the influence of external gravitational forces from celestial bodies.

The Green Giant
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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!
 
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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 amount of time that it would exist would make use of it totally useless.
 
Even when you look at atomic scale gravity is there. It just is extremely little that it was originally ignored in the standard model...
 
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.
 
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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.
 
True, but you would still experience weightlessness.
 
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.
 

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