Columbus' Miscalculation: How Far Around is the Round Earth?

American Minute ^ | October 12, 2019 | Bill Federer

[Perseverando]

Columbus was looking for a SEA route to India and China because 40 years earlier Muslim Turks conquered Constantinople in 1453 cutting off the LAND routes.

A biography of Columbus was written by Washington Irving in 1828, titled A History of the Life and Voyages of Christopher Columbus.

In it, Irving created an imaginative dialogue of Europeans arguing over whether the Earth was round or flat. His book was so popular, that people actually thought such a debate took place when it had not.

Washington Irving was known for mixing entertainment with history and legend.

He wrote Rip Van Winkle, The Legend of Sleepy Hallow, and Diedrich Knickerbocker's A History of New-York from the Beginning of the World to the End of the Dutch Dynasty, filled with tales of visits from St. Nick coining to New York City, which he nickname "Gotham."

Europeans knew the Earth was round.

Pythagoras had speculated that the earth was a sphere in the 6th century BC, and Aristotle validated it in the 4th century BC.

In the 3rd century BC, Eratosthenes computed the circumference of the earth with amazing accuracy.

He had heard that at Aswan, Egypt, the sun cast no shadow at noon on the summer solstice, June 21, yet at the exact same moment in Alexandria, Egypt, a column cast a shadow with a 7.2 degree angle.

7.2 degrees is 1/50th of a 360 degree circle.

It was known that the distance between Alexandria and Aswan was 5,000 stadia or 800 kilometers (approximately 500 miles).

All Eratosthenes had to do was multiply 800 times 50, which equals 40,000 kilometers, just 75 kilometers less than the actual circumference of the Earth, 40,075 km, or 24,901 miles.

Eratosthenes also calculated distance

[Pelham]

“It’s possible that the idea of a flat Earth has only caught on in quite modern times.”

The idea that the ancients thought the Earth was flat is a modern conceit. Romans knew that the Earth is round, as did the Greeks before them.

Any culture capable of sailing over the horizon figured it out.

[Ozark Tom]

Torsional pendulum was added as the regulation component for a clock to allow time keeping on a ship. British Navy secret for a bit.

[Openurmind]

Thing was, even with an accurate time piece, a universal global standard had to be in place first. And where did it start in longitude? Athens or Greenwich or Deli?

Until there was an agreed or forced upon global starting longitude line to time it from it was just never going to happen and ever be accurate. :)

Let alone the huge hurdle that Sailboats could not navigate in a straight line at a consistent speed... honestly? it was kind of an incredible thing that they actually figured it out. :)

[elbook]

“did not sail west in search of the east Indies..”

Earlier ... (perhaps some did but getting back is the problem - just like the vikings/irish monks/fishermen/others are thought/known to have reached the eastern coast of canada centuries before Columbus’ voyages.

It had to do with unfavorable winds in the north atlantic, so sailing far south and then west was the actual route used a great deal and why Brazilians speak Portuguese today. The route up the northern coast america - northeast and then east was the common return route later because of the wind patterns.