Asimov's Chronology of Science and Discovery (Private)
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biped4000000 BCEBipedal speciesFree hands allowed hominids to manipulate objects, bring them closer to our senses and thus increase brain capacity, priming the feedback loop.GeneralDiscovery
stone-tool2000000 BCEStone toolsCrows are known for tool use, and chimps can fashion tools out of sticks. Humans learned to sharpen stones into edges and points.bipedGeneralInvention
fire500000 BCEFire tamedInitially, fire had to be found (eg. lightning strikes). Eventually, it became possible to start via friction caused by spinning sticks.GeneralInvention
200000 BCECeremonial burialNeanderthals were the first hominids to bury their dead rather than leaving their bodies to scavengers and rot. Food and floweres were often buried with the corpse.CultureSocial
art20000 BCEArtSome of the earliest paintings were found in caves, seem to be drawn for ceremonial, religious purposes.ceremonial-burialCultureSocial
bow20000 BCEBows and arrowsFirst object to slowly store energy and release it all at once. Much safer to hunt from a distance.stone-toolWarInvention
oil-lamp20000 BCEOil lampsTorches make fire portable, but a primitive lamp is way more convenient.fireGeneralInvention
animal-dom12000 BCEAnimals domesticatedDogs were first to be domesticated, followed by goats. This enabled hunter gatherers to become shepherds with a much more secure food supply.bipedGeneralTechnique
agriculture8000 BCEPlants domesticatedDeliberate seed planting and harvesting allowed the same land area support a larger population, but bound farmers to their land. Cities emerged for protection.animal-domGeneralTechnique
pottery7000 BCEPotteryGourds had to be found, and baskets could only large, dry objects. Pottery began as a technique for waterproofing baskets, and enabled carrying liquids and powders.bipedCultureInvention
fish-nets6000 BCELinenLinen made out of interwoven flax fibers enabled strong cords. Interleaving these cords enabled fishing nets and clothing.stone-toolGeneralInvention
raft6000 BCERaftsLashing logs together to form a floating wooden platform enabled people to cross longer stretches of water.stone-toolGeneralInvention
sickle6000 BCESicklesStone knives to help cut down stalks, and hand mills in the style of mortar and pestle.stone-tool, agricultureGeneralInvention
irrigation5000 BCEIrrigationPreviously farmers had to rely on rainfall, suffered in droughts and built their farms near rivers, which could also flood. Irrigation ditches allowed farms to plant further from rivers and more deal with flooding.agricultureGeneralTechnique
scale5000 BCEWeight scalesFor comparing weights or comparing to a reference weight.Egyptstone-toolMathTechnique
copper4000 BCECopperFirst obtained from metallic nuggets, metals (meaning "to search for" in Greek) were smelted using fire, and then molded into desired forms. Still fragile, stone-toolGeneralTechnique
simple-sundial4000 BCESimple sundialsA stake placed vertically into the ground gave a general sense of time of day. Likely also split the day into 12 hours.Egyptstone-toolGeneralInvention
bronze3600 BCEBronzeCopper is rarely pure in nature, some alloys are poisonous (eg. copper + arsenic), but copper + tin is hard enough to compete with rock.copperGeneralTechnique
cart3500 BCEWheeled cartsEven with animals in tow, dragging heavy objects on sleds was tough. Rollers could be added to the sledge, but this was still inefficient. Wheels with rollers inside the cart were a game changer.copperGeneralInvention
river-boat3500 BCERiver boatsCarrying heavy loads on water is far easier than on land: no rocks, no hills, no ridges. Boats were first used on the Nile, which unlike the Tigris is flat and has predictable winds from the north.EgyptraftGeneralInvention
writing3500 BCEWritingEarliest use of writing was for ledgers, which led to symbols for fruit, frain, man, and ultimately hieroglyphics.Sumerstone-toolGeneralSocial
plow3500 BCEPlowsScattering seeds on the ground led to random planting patterns. Digging furrows in the soil and planting seeds inside sped up the rate of growth.SumeragricultureGeneralInvention
nation3100 BCENationsIrrigation meant more coordination since water was a shared resource. As settlements grew in complexity and density, city-states blended together. This first happened in the Nile delta in Egypt.EgyptagricultureCultureInstitution
candle3000 BCECandlesOil could be spilled and spread dangerous fire, By surrounding a flame with animal fat, the solid can illuminate and serve as a container.Egyptanimal-dom, oil-lampCultureInvention
calendar2800 BCECalendarSome phenomena, like seasons, vary over hundreds of days. The moon cycle is a convenient length (~30 days), and about 12 of them make for a seasonal cycle. Egyptsundial, writingCultureInvention
2650 BCEStone monumentsSurplus of food meant more time to dedicate to showcase national greatness or build elaborate tombs for leaders.Egyptnation, ceremonial-burialDesignInstitution
literature2500 BCELiteratureOral storytelling is as old as speech, but writing allowed to codify epics. Gilgamesh is the first written tale.SumerwritingCultureInstitution
glass2500 BCEGlassMade out of sand and technically a liquid, glass can be made transparent and more beautiful than pottery. Originally used as ornaments, not vessels.EgyptfireGeneralTechnique
empire2340 BCEEmpiresSumerian city states fought one another, eventually Sargon of Akkad conquered Sumer and ruled over people of different languages and cultures, with Akkadians superior.SargonAkkadnationCultureInstitution
horse2000 BCEHorsesOxen are strong but dumb and slow, while donkeys are smart but weak. Tamed horses were a good compromise, initially used for driving chariots, eventually much more.animal-domGeneralTechnique
numbers1800 BCENumber systemBase 60 was first used by Sumer because it is divisible by so many numbers. This is why there are 6*60 degrees in a circle, which is conveniently close to 365. Seven known planets led to the week.EgyptwritingMathInvention
fermentation1800 BCEFermentationFruits that are left standing ferment and form alcohol and other sugars. By 1800 BCE, laws were in place for misdeeds committed while drunk, and the process of leavning bread was perfected.EgyptagricultureScienceDiscovery
law1775 BCECode of LawsSocial conventions work up to a point, but a complex society needs more hierarchy, mistrust, and a need to codify custom. First known law code was inscribed by Hammurabi on an 8-foot tall stone pillar.King HammurabiBabylonwriting, empireCultureSocial
medicine1550 BCERecorded medicineAncient medical remedies included ritualized behavior, use of plants and animals. First surviving account of medical remedies is called Eber's Papyrus.Egyptceremonial-burial,writingScienceDiscovery
alphabet1500 BCEPhonetic alphabetTo simplify complex ideographic written languages of the time, the Phonecian alphabet instead used a symbol for each sound to construct words.PhoeniciawritingCultureSocial
monotheism1375 BCEMonotheismEarlier humans believed in many supernatural influences, one for each common and abstract object. Amenhotep first accepted just one god (sun), but his reign failed, eventually central to Judaism.Pharoah Amenhotep IVEgyptCultureSocial
dye1200 BCEResistant dyesEarlier artists used colored soils for paintings, limited color palette. Blue and red was later found in indigo and madder extracted from plants. One sun and water resistant dye came from snail in Tyre.PhoeniciaartCultureInvention
sea-navigation1100 BCESea navigation Sea ventures were restricted to coast hugging, and the distant sea was feared and revered (cf. Homer). Phoenicians used the big dipper to find north, and relied on oars to mitigate bad winds.Phoeniciariver-boatGeneralTechnique
steel1000 BCESteelSmelting using wood never yielded iron because the flame wasn't hot enough. Charcoal, formed by burning wood with low oxygen, burned hot enough to melt iron. Initially too fragile, alloying with carbon yielded steel.HittitebronzeGeneralInvention
arch750 BCEArchitectural archesTwo vertical pieces capped by a horizontal roof is simple but weak and not condusive to long spans. Arranging the cover in a semicircular arch is more structurally sound.Etruscanstone-monumentDesignTechnique
aqueduct700 BCEAqueductsCities were built close to fresh water, but as they grew further from the river, needed water delivery infrastructure beyond wells.SennacheribAssyria
stone-monument, irrigation
zoo700 BCEZoosHunting animals for food, sports, artifacts was common. Keeping rare animals in zoos and plants in botanical gardens was first done in Assyria.SennacheribAssyriaanimal-domDesignInstitution
sundial700 BCE Improved sundialsGnomon was tilted north and hours were labeled.Egyptsimple-sundialScienceInvention
library640 BCELibrariesBooks on clay or papyrus were rare and expensive since they had to be manually copied by literate scribes. Only monarchs could accumulate thousands of books.AshurbanipalAssyrialiterature, nationDesignInstitution
coin640 BCECurrency (Coins)Trade between cultures was done by barter, but required a double coincidence of wants. Gold became the default currency, and was meticulously weighed until coins of standard weight were introduced.ArdysLydiascale, nation, writingCultureSocial
eclipse585 BCESolar eclipse predictedEclipses were seen as frightening, evil omens. The first solar eclipse was predicted by Thales on May 28, 585 BCE.ThalesGreecenumbers, calendarSpaceTechnique
water-element580 BCEWater as elementWhat is everything made of? Thales theorized everything was fundamentally made of water. ThalesGreeceScienceDiscovery
520 BCEIrrational numbersPythagoras first believed whole numbers including fractions were the basis of the universe. However what about a unit isoceles right triangle with hypotenuse √2?PythagorasGreecenumbers, writingMathTechnique
realistic-maps510 BCERealistic mapsA Greek traveler traveled the Persian empire and drew a realistic map covering thousands of miles, including parts of Europe, Africa and Asia.HecateusGreecewriting, empireGeneralInvention
500 BCEOcean navigationSpurred by depleted tin resources needed for bronze, Phoenicians ventured through Gibraltar and into the Atlantic, finding "tin islands", potentially Britain. Likely circumnavigated Africa.Phoneciasea-navigation,bronzeGeneralTechnique
cadaver500 BCEHuman dissectionAnimals had been butchered so much was known about their internal organs, not so humans. Saw arteries, veins, nerves.AlcmaeonGreecemedicineScienceTechnique
abacus500 BCEAbacusEach row represents a power of ten, and contains ten beads. A very early and important computing machine.EgyptnumbersMathInvention
venus-named500 BCEVenus namedThe Babylonians first saw the evening star (Hesperos), and the morning star (Phorphoros), but these turned out to be the same planet, Venus.PythagorasGreeceSpaceDiscovery
480 BCEDream interpretationOnce viewed as messages from the gods (eg. Joseph in Bible), Heracleitus suggested dreams have no meaning outside one's own thoughts.HeracleitusGreeceScienceTechnique
atom440 BCEAtomsLeucippus theorized that every event has a natural cause. Democritus expanded this suggesting that all matter was composed of tiny particles, and maybe there are billions of stars that are too far to be seen.DemocritusGreecewater-elementScienceDiscovery
epilepsy420 BCEEpilepsyEpilepsy the disease discovered. Hippocrates thought disease was due to a misbalance between the four humors: blood, phlegm, bile, black bile.HippocratesGreecemedicineScienceDiscovery
catapult400 BCECatapultGreek hoplites weilding armor, sword and shield were effective against other units but not city walls. Catapults were designed to do that, first artillery.DionysiusGreecenumbers,bowWarInvention
university387 BCEAdvanced schoolsPlato founded a school on grounds once owned by Academus, so called the Academy. Plato's student Aristotle founded his own school called Lyceum.PlatoGreecelibraryCultureInstitution
350 BCENon-geocentric theoryPhilolatus thought everything rotated around some central fire (not earth). Ponticus thought maybe Venus and Mercury circled the sun (but sun circles the earth).PhilolausGreeceSpaceDiscovery
logic350 BCELogicFirst formal system of reasoning. Aristotle wrote "Organon", describing how to draw conclusions from premises.AristotleGreecenumbersMathTechnique
spherical-earth350 BCESpherical earth theoryLooking around, the earth looks flat, but over long distances it seems to have curvature (eg. ships hulls dissapear first, then masts). PythagorasGreeceocean-navigationGeographyDiscovery
five-elements350 BCEFive elements theorizedAristotle's model had concentric circles of elements: earth at center, surrounded by water, surrounded by air, surrounded by fire (sometimes seen as lightning), and the heavens made of aether.AristotleGreeceatomScienceDiscovery
350 BCEAnimal classificationDissected 500 species, in particular the dolphin, unlike other fish, seems to have placenta and milk, so classified it with mammals.AristotleGreeceanimal-domScienceDiscovery
star-maps350 BCEStar mapsImproved on the best earth maps. The sky is hard to map because there are no physical landmarks. Drew out latitude and longitude lines to identify locations.EudoxusGreecerealistic-mapsSpaceTechnique
botany320 BCEBotany bookTheophrastus, one of Aristotle's students, wrote a book on botany, including 550 plant species.TheophrastusGreeceuniversityScienceDiscovery
paved-road312 BCEPaved roadsOnce carts and wheels were common, roads were needed. Initially covered by gravel, later paved, roads led to better logistics for commerce and armies.Appius ClaudiusGreecestone-monument, cartGeneralInvention
geometry300 BCEGeometry The Greeks took a more theoretical approach to geometry than the applied Egyptians. Euclid's "Elements" compiled the axioms (taken as given) and built geometry up from them.EuclidGreecelogic, universityMathTechnique
tides300 BCETidesPytheas explored the British Isles, as far as Norway or Iceland. He observed and described tides (not visible in the Mediterranean due to narrowness of Gibraltar)PytheasGreeceocean-navigationGeneralDiscovery
arteries-veins300 BCEArteries vs veinsDistinguished between arteries and veins, and thought that arteries carried air.PraxagorasGreececadaverScienceDiscovery
brain-areas280 BCEParts of brainHerophilus divided nerves into sensory and motor, described the retina. Erasistratus distinguished the cerebrum and cerebellum. Then paused for religious reasons.Erasistratus, HerophilusGreececadaverScienceDiscovery
moon-sun-size280 BCEMoon and sun size estimateWhen Anaxagoras suggested the Sun was the size of Greece, he was exiled. 200 years later, Aristarchus estimated sun to be gigantic and venus/mars as comparable in size to Earth.AristarchusGreece
lighthouse280 BCELighthousesThe Lighthouse of Alexandria (at Pharos) stood 280 ft high, with stairs to carry wood up. The light of the burning wood was visible 35 miles out.Greece
water-clock270 BCEWater clocksSundials only work when there's sun, and aren't portable. Hourglasses and candles could also work. Water clocks were more precise, but still crude.CtesibiusGreecesundial, nationMathInvention
lever-math260 BCELever mathematicsLevers have been used for a long time, but Archimedes calculated the math. Archimedes also worked out buoyancy and estimated the value of pi to be 3.142.ArchimedesGreecelogic, universityMathTechnique
earth-size240 BCEEarth size estimateIn Aswan, the sun is directly overhead. By comparing it to the 7 deg offset in Alexandria and using the cities' relative location Eratosthenes estimated earth circumference to be 25k miles.EratosthenesGreecegeometry, river-boatGeographyDiscovery
year-number240 BCEStandardized yearsFormerly years were called "the seventh year of King X". Eratosthenes matched these dates onto a global timeline.EratosthenesGreececalendarCultureSocial
great-wall214 BCEGreat WallGreat Wall is largest construction project ever. First made of earth, later of brick, extending for 1500 miles. Shih Huang Ti burned all known books in 214 BCE, explaining why little is known about China before then. Shih Huang TiChinastone-monumentDesignTechnique
parchment170 BCEParchmentEgypt was the only source of papyrus, and they were not eager to share. Parchment from treated animal skins is more durable, can be reused, but is expensive.Eumenes II
Pergamum (Greece)
moon-distance150 BCEDistance to moon estimateHipparchus made the first trig tables. He used trig to calculate the moon's parallax by comparing its position to the stars from multiple points on earth.HipparchusGreecegeometry, river-boatSpaceDiscovery
134 BCEBetter star mapsImproved on the previous star maps by including magnitudes, and including over a thousand stars, and incorporating lat long from earth maps.HipparchusGreecestar-mapsSpaceTechnique
glass-blowing100 BCEGlass blowingPreviously, glass was hard to manipulate, but it was found that glass could be blown like a soap bubble. Glass became cheaper and could be used for vessels.
Syria (Greece)
water-wheel85 BCEWaterwheelsHuman and animal muscle was expensive. What if you could use inanimate forces like wind pushing sails? First powered mills.cartGeneralInvention
julian-calendar46 BCEJulian calendarJulian calendar adopted, inspired by Egyptian calendar. Some months had 30 and some 31 days. An extra day every four years (leap).SosigenesGreeceyear-numberGeneralInstitution
climactic-zone25Climactic zonesMela suggested earth be divided into north and south frigid zones around the poles, a torrid zone around the equator and temperate zones in between.Pomponius MelaGreece
50Recorded medicinal plantsAfter serving as a medic in Roman army, he wrote "Materia Medica" which described 600 plants, 1000 drugs. Start of pharmacology.Pedanius DioscoridesGreecemedicineScienceDiscovery
steam-engine50Rudimentary steam engineWorked like a modern lawn sprinkler, using the force of flowing steam for motion. Had no bearing on society.HeroGreecefireGeneralInvention
paper105PaperInstead of relying on expensive reed, process made paper from any tree. Took 1000 years to reach Europe.Tsai LunChinaparchmentGeneralInvention
140Geocentric universePtolemy wrote that the sun and planets rotate around the earth in circular planets and worked out the math for predicting planetary motions. Remained canon for 14 centuries.PtolemyGreecestar-maps-betterSpaceDiscovery
spinal-cord180Spinal cordGalen worked at a gladiator school which gave him insights into human anatomy. He also cut animals’ spines to see resulting paralysis.GalenGreecemedicineScienceDiscovery
algebra250AlgebraMost Greek math focused on geometry, but Diophantus focused on problems that were less visual, usually equations with multiple unknowns.DiophantusGreecegeometryMathTechnique
tea250TeaReduced infection since it required water to be boiledChinaCultureDiscovery
alchemy300Recorded alchemy Chemical change was intuitively understood: pottery from clay, metals from ore, glass from sand. Zosimus summarized ancient alchemy. Ultimately led nowhere.Zosimus
Egypt (Greece)
metal-stirrup300Metal stirrupsLarger horses were bred to carry more, so riders were carried on saddles. Stirrups gave more stability for the rider and enabled to strike from horseback.Chinasteel, horseWarInvention
wheelbarrow400WheelbarrowsA one wheeled cart that relied on lever action to carry a lot more than a human can. Potentially invented much earlier than 400.ChinasteelGeneralInvention
dome537Architectural domesAdvanced dome making techniques perfected. The Hagia Sophia was 108 feet across and 180 feet high.Emperor JustinianRomegeometry, archDesignTechnique
silk-europe552SilkSupposedly invented in 2480 BCE in China, Silk was in high demand in Rome and expensive, so Justinian arranged to bring back silkworms and the silk making process from China. By 552 Constantinople was producing.Emperor Justinian
turnplow600TurnplowsA plow with a vertical knife-blade that cut deep into the earth. Useful for damp, moist ground, led to increase in carrying capacity.Slavsplow, steelGeneralInvention
greek-fire673Greek fireThe Greeks devised a napalm-like weapon which would continue to burn on water, enabled them to defend Constantinople from Arab invaders through terror.CallnicusByzantiumcatapult, alchemyWarInvention
porcelain700PorcelainEventually came to Europe, known as “China” and became the luxury replacement for wood dishes.ChinapotteryCultureInvention