“The Earth is perfectly round.”

It's a common and understandable assumption that our home planet is a perfect sphere. From our perspective on the ground, or even in many images from space, the Earth appears perfectly round. However, this widely held belief is actually a misconception. The Earth is not a perfect sphere; instead, it is an oblate spheroid. This means our planet bulges at its equator and is slightly flattened at its poles.

This scientific understanding isn't new. The theoretical basis for the Earth's true shape was proposed by Isaac Newton in the late 17th century, who reasoned that the planet's rotation would cause it to flatten at the poles and bulge at the equator due to centrifugal force. His predictions were later confirmed by 18th-century geodetic expeditions, notably those sent by the French Academy of Sciences to Peru and Lapland, which conducted precise measurements of meridian arcs at different latitudes. These expeditions provided the observational evidence that solidified the understanding of our planet's true, slightly squashed form.

The reason this myth persists is largely due to scale and simplified representations. The difference between the Earth's equatorial diameter and its polar diameter is approximately 43 kilometers (27 miles). While this is a substantial distance, it's a tiny fraction of the Earth's overall size, making the bulge imperceptible to the naked eye, even from orbit. Globes and maps, designed for general use, often depict a perfectly spherical Earth for simplicity, further reinforcing the misconception rather than highlighting the subtle but significant reality of its oblate spheroid shape.