# The gravitational center of the Earth

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• qnt200
In summary, the gravitational field's influence is not felt near the center of the Earth due to the Earth and Moon orbiting around the center of mass of the Earth-Moon system. However, an object placed at the barycenter would still be attracted towards the center of the Earth, as everything on/inside the Earth is in free fall with respect to the Moon, but not with respect to the Earth itself.
qnt200
We know that gravitational forces are nullified near the center of the Earth, so the gravitational field's influence is not felt. Is it because of the Moon's gravitational field that the area of zero gravity has shifted away from the center of the Earth? If this is the case, this eccentric area will orbit around the center of the Earth due to the moon's orbit.

The gravitational field is never ”felt” in free fall regardless of where you are. Whether the gravitational forces equate to zero depends on your frame of reference.

If you want to consider the Earth-Moon system, them the center of mass is indeed not at the center of the Earth.

The Earth and Moon orbit about the center of mass of the Earth-Moon system. This point, called the barycenter, is about 1,700 km below the Earth's surface.

Ibix, PeroK, Delta2 and 1 other person
However, it's important to stress that an object placed at the barycentre would still be attracted towards the centre of the Earth. I.e. the fact that the Earth and the Moon orbit their mutual centre of mass doesn't affect where the forces produced by the Earth on itself cancel out. This follows from the point Orodruin made - everything on/inside the Earth is in free fall w/r to the Moon, but not w/r to the Earth itself.

## 1. What is the gravitational center of the Earth?

The gravitational center of the Earth is the point at which the force of gravity is equal in all directions. It is located at the center of the Earth's mass, which is also known as its core.

## 2. How is the gravitational center of the Earth calculated?

The gravitational center of the Earth is calculated using the mass and radius of the Earth. It is determined by the combined effects of the Earth's rotation, shape, and density.

## 3. Does the gravitational center of the Earth change over time?

The gravitational center of the Earth does not change significantly over time. However, it can vary slightly due to changes in the Earth's mass distribution, such as tectonic plate movements or changes in the amount of water in the oceans.

## 4. How does the gravitational center of the Earth affect objects on the surface?

The gravitational center of the Earth is what gives objects on the surface their weight. The closer an object is to the center, the stronger the force of gravity it experiences. This is why objects weigh less at the equator, which is farther from the center, than at the poles.

## 5. Can the gravitational center of the Earth be changed?

The gravitational center of the Earth cannot be changed by human actions. However, natural events such as meteor impacts or volcanic eruptions can cause small shifts in the Earth's mass distribution, which can in turn affect the location of its gravitational center.

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