The true shape of the Earth is best described as an oblate spheroid or an ellipsoid -a sphere that is slightly flattened at the poles and bulging at the equator. This shape results from the Earth's rotation, which causes a centrifugal force that makes the equator swell outward while the poles flatten

. Key points about Earth's shape:

• Not a perfect sphere: While Earth appears round from space, it is not perfectly spherical. The equatorial diameter is about 21 kilometers (13 miles) greater than the polar diameter due to this bulging effect

• Surface irregularities: Mountains, ocean trenches, and uneven mass distribution create bumps and valleys on the Earth's surface, making it somewhat lumpy rather than a smooth ellipsoid

• Dynamic shape: Earth's shape changes over time due to tectonic movements, post-glacial rebound, tides, and other geological and atmospheric processes

• Geoid concept: Scientists use the geoid, a model representing mean sea level influenced by Earth's gravity field, to describe Earth's irregular shape more precisely

• Scientific confirmation: The oblate spheroid shape was first proposed by Isaac Newton in the 17th century and later confirmed by expeditions measuring degrees of latitude near the poles and equator in the 18th century

In summary, the Earth is an oblate spheroid with a complex, ever-changing surface shaped by rotation, gravity, and geological activity, rather than a perfect sphere or a flat disk. This understanding is supported by centuries of scientific observation and modern geodetic measurements