How to Measure Earth?

Saturday Morning Astrophysics at Purdue · 4K views · 2023 · 3:50

Open on YouTube

Fundamental physicsother

Why the open web links it

Demonstrates how to measure Earth's circumference using a method devised by Eratosthenes over 2000 years ago.

Linked by 2 independent sites, 2 of them widely read in the 2026-10 crawl of the open web, including purdue.edu, ufpa.br.