Pythagorean Theorem proof
A right triangle. This is the proof of the Pythagorean Theorem supposedly written by Pythagoras about 500 BC: The Pythagorean Theorem says that in a right triangle, the sum of the squares of the two right-angle [...]
A right triangle. This is the proof of the Pythagorean Theorem supposedly written by Pythagoras about 500 BC: The Pythagorean Theorem says that in a right triangle, the sum of the squares of the two right-angle [...]
Sapodilla tree - where chewing gum comes from Who invented chewing gum? Nobody knows when the first person began to chew gobs of sap from trees, but it was probably [...]
Silver mining slaves at Laurion, near Athens Why did people want silver? People first mined silver in the Bronze Age. Like gold, silver is a great way to help people trade. [...]
Opium poppy flower Opium comes from a kind of poppy flower. It evolved around 100 million years ago in West Asia and Central Asia. People probably realized as soon as they got to West Asia, about 60,000 [...]
History of influenza: Influenza comes from chickens: this is a clay hen whistle from Mohenjo Daro (ca. 2700 BC, now in Brooklyn Museum) What is influenza? Influenza is a virus that mostly [...]
History of Dysentery: Dysentery came from germs in your drinking water. Here people are washing clothes in the river (India) What is dysentery? Dysentery means having trouble with your insides [...]
The beginning of meanders? An Egyptian pot with spirals (Naqada II, ca. 4000 BC) What are meanders? A meander is a kind of pattern that artists used to decorate the [...]
A cider press with big wooden screws What is a screw? People always count screws as a separate kind of simple machine. But really screws are just one kind of inclined plane. [...]
Cicero, a Roman philosopher The Stoics were a group of philosophers who first began teaching their ideas in the Hellenistic period. Stoicism was founded by a man named Zeno, who lived from 335-263 [...]
This is supposed to be a bust of Pyrrhon, the founder of Skeptic philosophy We don't know as much as we might like to about the activities of Plato's Academy after [...]