Tag Archives: Greeks

Plumb

A plumb line or plumb bob.

Last post I rattled on about how the well at Syene was plumb.

‘Plumb’ means straight up-and-down. Builders used to use a plumb line—a string with a weight tied onto it—to check that their walls were straight up-and-down. A plumb line will always point to the center of the Earth. Nowadays they use a spirit level. Builders who dug wells made sure that the hole they dug was plumb—pointing directly toward the Earth’s center.

Why was it so important to Eratosthenes that the well at Syene (a town located on the Tropic of Cancer) was pointing directly at the Earth’s center at noon on June 21st—the Summer solstice?

Back to the beginning of The Western Civ User’s Guide to Time & Space

Eratosthenes


Head-Librarian Eratosthenes explains to a student how to laminate a dust jacket.

In an earlier post, I hinted about how over 2,000 years ago somebody calculated the circumference (how big around) of the Earth. This guy did it using only a well, a protractor and a stick (okay, maybe instead of a stick he used a column, but you could use a stick and get the same result).

I’m talking about Eratosthenes, the head librarian at the Great Library of Alexandria. Alexandria is an ancient city in Egypt, located where the Nile River flows into the Mediterranean Sea. Many scholars lived in Alexandria—like Ctesibius, who perfected the water-clock.

Back to the beginning of The Western Civ User’s Guide to Time & Space

It’s about cyclical time

I told you the story of Persephone so you’d remember one thing: for the ancient Greeks, time was a cycle. The seasons followed each other over and over again. The Greeks didn’t think of time as a progression of numbered years, as we do. They named the years after whomever was the archon (ruler or king) at the time. Later on the Greeks numbered years by a 4-year cycle, called an olympiad. The Olympic games were held every fourth year, then the cycle started over.

The Greeks weren’t the only ones who think of time as a cycle.

Disney’s African tale The Lion King opens with the song The Circle of Life and its theme is cyclical time.

People who follow Indian and Asian religions—Hindus, Sikhs and Buddhists—think of time as a cycle. The problem of ‘which came first, the chicken or the egg?’ is a puzzler to us because we think in linear time. How can you have an egg without a chicken first? Or a chicken without an egg first? It’s not puzzling to someone who thinks of time as a cycle. Imagine a chicken and an egg riding a merry-go-round. The chicken follows the egg, which follows the chicken, which follows the egg, and so on and so on. It’s a continuous loop.

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Siege of Troy—tight sketch