Who Discovered The Earth is Round?

If you were taught it was Christopher Columbus, you aren’t alone. But just how much we knew thousands of years ago may surprise you!

Image credit: Free HD Wallpapers, via http://www.listofimages.com/fantasy-mystical-fantasy-mystical.html.
Image credit: Doug Zubenel.
Image generated by me, using the free software stellarium.
Image credit: MoonConnection.com.
Image credit: Micor Dimaguila.
Image credit: T. Scholten of
Image credit: Randy Russell.

“The church says the earth is flat, but I know that it is round, for I have seen the shadow on the moon, and I have more faith in a shadow than in the church.”

But contrary to popular belief, this question wasn’t settled in the 1400s and 1500s (with the circumnavigation of the globe), but more than 2,000 years ago, in the ancient world! And what’s perhaps most amazing? It was done using nothing more than the Sun. Here’s how.

Image credit: Danilo Pivato.
Image credit: Ken Tape.
Image credit: The Centre for Planetary Sciences at UCL/Birkbeck, using a pinhole camera.
Public domain image.
Image credit: B. A. Perara.
Image credit: Bora Shin.
Image credit: Larry Phillips original, modified by me.
Image credit: UNEP, 2007, via http://postconflict.unep.ch/sudanreport/sudan_website/index_photos_2.php?key=deserts.
Image credit: E. H. Bunbury.
Image credit: U.S. Military, White Sands Naval Base, New Mexico.



The Universe is out there, waiting for you to discover it.

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Ethan Siegel

The Universe is: Expanding, cooling, and dark. It starts with a bang! #Cosmology Science writer, astrophysicist, science communicator & NASA columnist.