Native American economy: Pomo people fishing (California, 1816) Fishing and gathering food When people first came to North America, maybe about 20,000 BC, they were probably mostly following the fish [...]
European trade goods (thanks to Nebraska Game and Parks Division) North American people made rapid scientific advances in the course of the 1500s AD, inspired by contacts with traders and [...]
Cloister at Moissac (ca. 1100 AD, southern France) The first part of the Middle Ages saw very little building of anything but houses in northern Europe, as people struggled to adjust to the fall of [...]
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 [...]
Plate tectonics: The world as seen from space (flattened out) The continents move around When you look at a map of the world, it seems as though it was always [...]
Now all this is mostly my own ideas, so I could be wrong. But see what you think: Sailors setting sail on a Greek warship I think that one important [...]
Nubian archers in the Middle Kingdom (from the Nubian museum in Aswan, Egypt). About 2000 BC. What is a mercenary soldier? Mercenaries (MURR-sinn-air-eez) are paid volunteer soldiers: they are soldiers [...]
When did people start to fight wars? Why do people fight wars? This woman, in the last stages of pregnancy, was tied up, beaten, and dumped in a lake by attackers. [...]
Two pythons: evolution of snakes When did snakes evolve? Snakes evolved from lizards only about 150 million years ago, during the Jurassic Period. This is during the time of the dinosaurs, about the [...]
A sewer from ancient Urartu (800s BC, now in eastern Turkey) As early as 800 BC, people in West Asia were digging ditches that led from their houses through the city streets [...]
