Space, GPS & MapsHistory of Science
Measuring the Earth With a Stick
Over 2,000 years ago a scholar measured the planet with shadows
No rockets, no satellites, no leaving Egypt. Around 240 BC, a librarian worked out the size of the whole planet. What did he measure?
You'll find out
- Why two cities had different shadows
- The one angle that sizes a planet
- How close he got to the real figure
Why it matters
Geometry turns a small measurement into a huge one. The same idea maps coastlines and measures the distance to stars.
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