Tag Archives: greek

How he did it

Just to recap from the last couple of posts: First, Eratosthenes guessed the Earth was round like a ball. Second, he knew that at noon on the Summer solstice, the Sun shone directly overhead in the town of Syene, which was 5,000 stadia south of Eratosthenes.

Third, Eratosthenes guessed the Sun was really big—huge, even. He noticed that shadows cast by the Sun are all parallel, so all the Sun’s rays must be parallel, too. Parallel means 2 or more lines that never touch—they stay the same distance from each other. Think train tracks.

SO, Eratosthenes—in Alexandria, 5,000 stadia north of Syene—put a stick (like the gnomon of a sundial) in the ground and made sure it was plumb. That stick was pointing down to the center of the Earth. If Earth is round, the well in Syene and Eratosthenes’ stick won’t be parallel, right? They’ll be at an angle to each other. Eratosthenes didn’t know exactly how many degrees that angle was, but in Alexandria at noon on June 21st, his stick cast a shadow.

There weren’t any shadows in Syene, because the Sun was directly overhead. He measured the stick, he measured the shadow, and used those measurements to draw an angle. The angle turned out to be a little over 7 degrees, or 1/50 of a circle.

Eratosthenes knew the distance from Alexandria to Syene was 5,000 stadia. He multiplied 5,000 by 50 to get the circumference of the Earth—250,000 stadia. In modern measurements that works out to be 28,738.418 miles or 46,250 kilometers.

The actual polar circumference of Earth is about 24,860 miles or just a bit over 40 thousand kilometers. The stadion Eratosthenes used may have been a little different from the standard unit. But even today, right now, if you search the internet for the circumference of the Earth, you won’t get just one answer.

Eratosthenes was a genius who used what he knew and observed, along with what he guessed at, to calculate something that no one knew—and he did it pretty accurately.

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

The well at Syene

So how did Eratosthenes figure out how big around the Earth is? Here’s how:

First, he assumed the Earth is round like a ball.

Well at Syene.

Second, he knew several things about a little town called Syene. It is 5,000 stadia (575 miles or 925 kilometers) directly south of Alexandria. There was a well in the center of town, dug deep and plumb—straight toward the Earth’s center. At noon on June 21st, the Summer solstice, you could see the Sun reflected on the water way down in that well, which means the Sun is directly overhead.

Bird’s-eye view of the Sun’s reflection in the well at Syene.

That’s because Syene is located on the Tropic of Cancer. If you happen to be standing on the Tropic of Cancer and it’s noon where you are on June 21 you can draw a straight line from the center of the Earth, through the Tropic of Cancer, to the Sun.

A stadion is an ancient Greek unit of measurement—it’s 600 feet (an eighth of a mile). Stadion is singular (nominative, singular, second declension); stadia is plural (nominative, plural, second declension). 5,000 stadia = 575 miles or 925 kilometers. I hope I declenched in all the right spots. Many thanks to my Greek-scholar pals Jackie J., Michele J. & Joann W!

What’s a Grecian earn?

About 14 drachmas an hour! Har har har!

Okay, can I get a do-over? I’m not entirely happy with the drawing I did for that last post about Greek measurements. Didn’t look Greek enough, or just didn’t have pizazz or something. So I drew a new version of it, this time taking the drawings on those wonderful old Grecian urns as my inspiration. Tell me what you think.

Here’s an old Greek urn—these drawings are gorgeous. I love the light terra-cotta-colored figures on a rich black background.

Here’s the new sketch.

Greek measurements

The Greeks measured length roughly the way the Egyptians did: a daktylos is a finger-joint, or inch; a pous is a foot, or 12 inches; a pēchys is a cubit, half a yard, or 18 inches. Longer distances were a bēma, a pace, 5 feet; an orgyia, a fathom, 6 feet; a stadion, 600 feet (an eighth of a mile); a milion, a mile.

Marathon

One of the important battles in the wars between the Greeks and Persians took place on the Plains of Marathon. Herodotus tells about how in 490 bc, when the Greeks were seriously outnumbered, a messenger named Pheidippides (Fay DIP e deez) ran from Athens to Sparta to get their help. Then he ran to Marathon to join the fight, THEN ran back to Athens to tell everybody that the Greeks won.

Around the world we still celebrate Pheidippides’ heroic run in races called marathons. If you run a marathon, it’s 26 miles and 385 yards—the distance from the Plains of Marathon to Athens. The very fastest runners have done it in a little over 2 hours!

Herodotus of Halicarnassus

Herodotus reading his Histories to the crowd

“These are the researches of Herodotus of Halicarnassus, which he publishes, in the hope of thereby preserving from decay the remembrance of what men have done, and of preventing the great and wonderful actions of the Greeks and the Barbarians from losing their due meed of glory; and withal to put on record what were their grounds of feuds.”

While the Greeks did think of time as a cycle, there was still a desire to reach back in time to remember stories from the past. We saw how Homer kept alive the story of the siege of Troy through his epic poem, the Iliad.

Herodotus (Hay ROD oh toos) was a Greek who lived in the fourth century bc and is thought to be the first historian. He wrote The Histories mostly about the wars between the Greeks and Persians and how they got started. Herodotus was a great storyteller, but what made him a historian is that he investigated, he did research—he got his information from several sources; he visited the places where the history took place; he went to the library; he interviewed people—then he arranged the information he’d gathered to explain how and why something happened.

I have a paperback copy of The Histories. It’s not an easy read, but I like to ‘dip into’ my copy and read whatever I open to. The battle of Thermopylae is in there—that story has since been made into a graphic novel and movie, The 300—and the battles of Marathon and Salamis. Herodotus included lots of oddball side-stories and observations, which are also fun. The Persian emperors Cyrus, Darius and Xerxes are in there (Xerxes is thought to be the party-boy king Ahasuerus from the biblical Book of Esther).

History is often about the big military battles and wars. I want this history, the one you’re reading right now, to be about ideas. But I’m telling you, if the Greeks hadn’t broken the will of the mighty Persian Empire and eventually beat ‘em, there would have been no flowering of art, literature, philosophy and democracy that happened after the wars—and was the Greeks’ gift to us.

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

The Iliad

The Iliad is an epic poem written by the blind poet Homer in the 4th century bc, about events that happen during the siege of Troy—known back then as Ilium—in the 12th century bc.

In those days poems like the Iliad were recited in front of an audience. They were written with a specific rhythm and often-repeated phrases in order to help the poet memorize the whole thing. The Iliad is mostly about war, the destruction it causes, and a code of honor that was part of Greek culture.

Because I’m a swell guy, I condensed the whole Iliad in to one sentence. You can take a really deep breath and recite it without stopping:

Nine years into the Trojan War the Greeks attack a town on Troy’s side and make off with a couple of Trojan girls Chryseis and Briseis Agamemnon takes Chryseis and Achilles who is the Greeks’ best warrior takes Briseis to be their girlfriends Chryseis’s dad offers to pay to get her back but Agamemnon says no dice Dad prays to Apollo Apollo inflicts a plague on the Greeks and a lot of them die Agamemnon figures out making Chryseis his girlfriend is the cause of this plague so he gives her back but he still wants a girlfriend so he makes Achilles give him Briseis this ticks Achilles off so he says he’s not going to fight for the Greeks anymore and even asks his mom Thetis who is a sea-goddess remember she married the mortal Peleus and wouldn’t invite Eris to their wedding to ask Zeus to help the Trojans who are the Greeks’ enemies so Zeus is on Troy’s side now and Achilles won’t fight so the Greeks get their hats handed to them there’s lots of fighting with some featured fights between Paris the shepherd with the good judgement who stole the beautiful Helen and Menelaus who is Helen’s husband and Hector and Ajax the Greeks don’t do so good the Trojans beat the Greeks back as far as their ships Diomedes and Odysseus get some inside info about the Trojans’ battle plans but the Trojans set one of the Greek ships on fire so things are looking pretty bad for the Greeks because without the ships how do they get back home Achilles still won’t help his pals but Nestor says let Patroclus wear Achilles’ armor so the Greeks will think yay Achilles is back in the game Patroclus is good but Apollo sees what’s going on and knocks Patroclus’ armor off of him and Hector kills him the Greeks and Trojans fight over the body and armor Hector gets the armor the Greeks get Patroclus’ body Achilles feels like a heel and tells Agamemnon okay I’ll fight those Trojans now Achilles’ mom Thetis the sea-goddess gets the god Hephaestus to make Achilles some new armor and Achilles goes out to fight the Trojan army who for some reason are sleeping outside the city walls and when they see Achilles coming they say feet do your stuff and try to beat it back inside Troy but they’re not fast enough and Achilles kills every Trojan he sees he even fights the god of the river Xanthus who complains about all the dead bodies Achilles sees Hector and chases him around the city three times until Hector stops running and fights Achilles but Achilles kills Hector and ties Hector’s body to the back of his chariot and drags it back to the Greek camp Patroclus gets a big funeral Achilles drags Hector’s body in circles around Patroclus’ coffin every day for the next nine days Hector’s dad the king of Troy tells Achilles come on man that’s not right Achilles says yeah you’re right I’m sorry and returns Hector’s corpse to the Trojans Hector gets a big funeral and everybody stops fighting for a while.

The reason I’m telling you this is because I’m interested in how people thought about time. Homer’s poem is about things that happened 800 years before he was born. Maybe the Iliad was a comment on wars happening in Homer’s own time. It was definitely a way of remembering events long gone.

The Iliad is an epic story, but too fanciful to be considered a history. We’ll have to look to another Greek to see who invented the idea of history.

Thanks to Spark Notes

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

The Greeks

Athena, Goddess of Wisdom

Let’s travel north from Egypt, across the Mediterranean Sea, to the island of Crete and the Greek mainland. It’s the Bronze Age, everybody!—from 3200 to 1100 bc—because some genius figured out smelting. Smelting is melting down 2 or more metals at very high heat, then combining them so when they cool, they’re a new metal, called an alloy. If you smelt the metals copper and tin, you get the alloy bronze. Bronze is stronger than copper or tin. Bronze was a handy material for making weapons and armor.

Like the Sumerians and Egyptians, the Greeks were farmers. Because Crete and the Cyclades are islands, they spent some time zipping around the Mediterranean in ships and trading with other people who lived along the sea. They used coins for conducting business—first made out of electrum, an alloy of gold & silver, later replaced with coins of pure gold and pure silver.

When we talk about the Greeks as a civilization, we’re talking about a bunch of individual city-states—like Athens, Sparta, Thebes and Corinth—who shared language, religion and culture. Sometimes they fought with each other, sometimes they banded together to fight a common enemy.

The Greeks were polytheistic—they worshiped many gods. Polytheism: poly= many; theo/deo=god.

These city-states were ruled by kings, but in Athens they began a system of government called democracy, where citizens can vote on who rules them.

The Greeks introduced theater; created statues and pottery; wrote epic poetry and songs; and developed a style of architecture using weight-bearing columns.