(Roughly) Daily

An image from The Catalan Atlas, 1375

When Christopher Columbus first set foot in what’s now the Bahamas, it was the lucky sum of a 1,400-year-old cartographical error and Columbus’s own miscalculations of the globe. The Genoese explorer believed the Eurasian landmass to cover nearly 2/3 of the earth’s circumference—the actual distance from Spain eastward to his target of eastern Asia was closer to 1/3 of the circumference.

Columbus’s image of the world was based on ancient maps that greatly overestimated the size of the Eurasian continent and depicted the planet’s circumference some 25 percent smaller than it actually was—a misjudgment compounded by his own wishful thinking and erroneous math. By his calculation, India lay within a 2,500-mile voyage west of Spain. He was off by about 8,000 miles.

Columbus’s errors are only a chapter in a series of discoveries, theories, and mistakes that tell the story of maps and mapmaking. Maps are a 10,000-year journey of humans trying to understand Earth. In 1492, most people had no idea what the world looked like; even some impressively accurate maps were full of myths and mistakes, from fantastical monsters to entire missing continents to swaths of terra incognita, or “unknown territory.”

Over time, errors were corrected and empty spaces were filled in, and today, much of the population walks around with a map of the entire Earth in their pocket that’s so detailed you can see your own front door…

Eight maps, from antiquity to today, that changed how we see the world: “Why Maps Are Civilization’s Greatest Tool.”

* Nicholas Chrisman

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As we find our way, we might might recall that it was on this date in 1415 that Henry the Navigator led Portuguese forces to victory over the Marinids at the Battle of Ceuta, the Muslim port on the North African coast across the Straits of Gibraltar from the Iberian Peninsula– which marked the beginning of the Portuguese Empire in Africa.  Henry remained a central figure in the early days of the Portuguese Empire and was a key driver of the 15th-century European maritime discoveries and maritime expansion. Through his administrative direction– including his patronage of cartographers– he is regarded as the main initiator of what would be known as the Age of Discovery.

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