Shape of the Earth

The Earth on the left is what we think of when we think of Earth's shape

It isn't though.

The Earth is a slightly flattened sphere, wider than it is tall.

We call this an Oblate Spheroid

The green line is 12,714 km

The red line is 12,756 km

The Earth is slightly wider than taller

What you may not know is how this affects gravity.

Gravity pulls everything down towards the Earth

Gravity is really pulling us towards the center of the Earth

This means the further you are from the center of the Earth the weaker gravity is.

So how does the shape of the Earth affect gravity?

Gravity depends on distance from the center of the Earth

The end points of the green line are closer to the center of the Earth than the end points of the red line

This means that at the North and South Pole the gravity is stronger than at the equator (the red line)

This means you weigh more at the poles than at the equator