How Flat is the Earth?

Photo by Lena Bell on Unsplash

The Earth is not round, I mean it’s not a perfect sphere. In fact it’s more like a potato or a pear. It’s flattened at the pole and bulged at the equator.

We call this potato, a geoid. It is the true hypothetical shape of the Earth where gravity is the same at every points. This surface coincides with the mean sea level. This lack of regularity makes the geolocation complicated. That’s why researchers created a base of…