Geodesy

"As Earth spins, its shape is slightly flattened into an ellipsoid, so that there is a greater distance between the centre of Earth and the surface at the equator, than the centre of Earth and the surface at the poles. This bigger distance, coupled with the rotation of Earth, results in the force of gravity being weaker at the equator than at the poles."

The shape of the world: pushed down
by its spin, “a flattened ellipsoid.” As if
a potter’s wet hands, while centering clay
on the wheel, let the rotation take over,
as if they stepped away to get a fresh cup
of tea, as if the spinning clay gathered a
wisp of the earth’s magnetic field to itself—
a cloud condensing, a blanket against the
solar wind—and made an atmosphere.
As if the potter returned as a goddess, a
geologist or mathematician, the maker re-
making, remade by the shape of the world.