100 ce

Archaeology

The Moche (Mochica) people of Peru experience a period of cultural expansion starting about this time, featuring giant pyramids, the rediscovery of lost-wax casting, and some of the most realistic pottery of the ancient world. See also 500 bce Construction.

Pseudo-Democritus (that is, a writer claiming falsely to be the much earlier Greek philosopher Democritus) writes Physica et mystica, the earliest known work on alchemy. See also 400 ce Chemistry.

Roman emperor Trajan [b. near Seville, Spain, September 18, 52 ce, d. Selinus, Cilicia, August 9, 117] reduces the limit on height for buildings in Rome to about 18 m (60 ft) for greater safety. See also 15 bce Construction.

Roman engineers learn shortly before this date how to use an ordinary round dome (not a cloister vault) to roof a square building. They insert slanting triangles, called pendentives, at the corners of the square to provide a connection between the circular dome and the square walls. This method becomes an important feature of Byzantine architecture. See also 100 bce Construction.

Roman engineers learn shortly before this date that two cylindrical vaults (essentially extended arches) can cross each other at right angles, creating a roof that can cover a large square.

Such cross vaults or groined vaults become common in both Roman and later medieval architecture. See also 200 ce Construction.

The city of Teotihuacán is laid out in a rectangular grid centered on a 6.4-km (4-mi) boulevard known today as the Avenue of the Dead. The entire city covers 20 sq km (8 sq mi), about the same size as contemporary Rome. It is eventually flanked by two enormous pyramids. The one known today as the Pyramid of the Sun is built first and covers about the same area at its base as the Great Pyramid of Khufu (Cheops). The Pyramid of the Moon, built centuries later, is only slightly smaller. See also 500 bce Construction.

The Chinese discover that dried, powdered chrysanthemum flowers can be used to kill insects. This is believed to be the first insecticide. The active ingredient, pyrethrum, is widely used today, especially on growing vegetables, since it is biodegradable and virtually harmless to mammals. See also 600 bce Food & agriculture.

The Chinese invent the multitube seed drill. See also 1500 bce Food & agriculture.

Horticultural writer Columella (a.k.a. Lucius Junius Moderatus Columella), in De re rustica ("country matters"), suggests the first known cold frames, glass (or transparent gypsum or mica) boxes in which to raise or grow plants sensitive to cold. He recommends putting them on wheels to roll outside on sunny days.

Glass windowpanes of the modern type appear in houses of the early Roman Empire. See also 100 bce Materials.

According to second-century Roman author Pausinius, "Theodorus of Samos [is] the first to discover how to pour or melt iron and make statues of it"; that is, he re-discovers cast iron. See also 31 ce Tools; 300 ce Materials.

Copper is in use in the Americas. Copper metallurgy is well-developed by the Moche in Peru (200 to 600 ce), so its use may have started even earlier. See also 2500 bce Materials; 500 ce Materials.

Spherics, by Menelaus of Alexandria [b. Alexandria, c. 70 ce, d. c. 130] written about this time, establishes spherical trigonometry. See also 100 bce Mathematics; 510 ce Mathematics.

Nichomachus of Gerasa's Introductio arithmetica, written about this time, summarizes the existing knowledge of number theory, including listing the only four known perfect numbers: 6, 28, 496, and 8128 (a number is perfect if the sum of its factors is the number, as 1 + 2 + 3 = 6 and 1 + 2 + 4 + 7 + 14 = 28). See also 300 bce Mathematics.

The double-armed catapult, rather like a large crossbow, is replaced by the single-armed catapult, more like a torsion-propelled spear thrower than like a bow. The new catapult is nicknamed the onager after the Asiatic wild ass, an animal that, legend has it, defends itself by kicking stones at pursuers. See also 332 bce Tools; 1100 ce Tools.

The Chinese invent methods for drilling deep wells to obtain salt water and natural gas. Their method uses ropes so that a person does not have to travel to the bottom of the well to dig it. The drill bit is a heavy pointed weight attached by ropes to a rocking bar at the top of the well. The rocker is used to raise and drop the bit repeatedly. Large bamboo derricks are used to raise and lower the cast-iron drill bits. The methods, with improvements, will be used for the next thousand years at least. Eventually the wells will reach 1460 m (4800 ft). See also 100 bce Energy; 347 ce Energy.

The Roman emperor Trajan, like Ptolemy II almost 400 years earlier, restores the canal begun by Pharaoh Necho II about 600 bce and completed a hundred years later by Darius the Persian. Unless constantly dredged, the canal soon fills up with blown sand. See also 280 bce Transportation; 640 ce Transportation.

The Chinese discover that horses can be hitched with one horse in front of another, allowing a heavier load without need for a wider road. The tandem hitch spreads through Europe in the Middle Ages. See also 110 bce Transportation.

The Greek merchant Alexander reaches the south of China by sea.

There is some evidence that horseback riders in India are using toe stirrups about this time -- the toe is inserted in a loop hung from each side of the saddle in the manner of a modern foot stirrup. See also 302 ce Transportation.