science technology han dynasty han dynasty ancient china divided eras western han capital dynasty eastern han capital witnessed significant chinese science technology great innovations addition dynasty china bce previous blast pig iron cast iron respectively han period saw development steel wrought iron use forge process drilling deep earth chinese lift surface boiled salt set bamboo crafted pipeline transport systems brought natural gas fuel techniques enhanced powered resulting widespread distribution iron tools facilitated growth agriculture soil planting straight rows crops improved heavy iron multiple tube iron seed drill invented han greatly enhanced production yields sustained population growth method supplying irrigation ditches water improved invention mechanical chain pump powered rotation draft animals transport irrigation water elevated operating trip pounding grain rotating metal rings mechanical driven astronomical sphere representing sphere earth quality life improved han han chinese bound bamboo write 2nd century invented process created writing medium cheap easy produce invention aided hauling heavy loads maritime ship stern mounted steering rudder enabled chinese venture waters interior lakes rivers open sea invention grid reference maps raised relief map allowed chinese better navigate terrain medicine new cure illnesses physically fit regulated avoid diseases authorities capital warned ahead time direction sudden earthquakes invention vibration sensitive device mark passing seasons special occasions han chinese variations calendar established efforts astronomy mathematics han era chinese mathematics include discovery square roots cube roots elimination scheme improved calculations negative numbers hundreds new roads canals built facilitate transport commerce tax collection communication movement military troops han era chinese employed types bridges cross waterways deep beam bridges arch bridges simple suspension bridges bridges han ruins defensive city walls brick rammed earth stand today modern perspectives science technology han professor research fellow professor assert han dynasty unique period history chinese science technology compare incredible pace scientific technological growth song dynasty argue influence scientific ancient philosophy chinese science continued lack definitive structure middle late eastern han early net growth ancient chinese science technology experienced peak second dynasty han studies classics long time hindered science declining rich scientific thought rapidly grown strengthened situation favorable development scientific structure happen seeds primitive structure science formed late eastern han disastrous occurred process social transformation leading greatest social disorder chinese history imagine effect science late professor university_of_cambridge author groundbreaking science china series stated han time especially later han relatively important periods regards history science china noted han astronomy sciences beginnings systematic philosophical skepticism thought embodied han works philosopher writing materials common writing found archaeological ancient sites han period shells bones beginning han period chief writing bamboo chinese clay silk cloth rolled strips bamboo string passed holes secured clay stamps written characters narrow flat strips bamboo arranged vertical columns maps drawn ink flat silk found tomb interred bce earliest known paper map found china dated located near incidentally oldest known piece paper chinese paper early eastern han eras coarse quality primarily wrapping paper process formally introduced eastern han court created process tree bark old fish nets boiled pulp stirred water wooden containing reed mat shaken dried sheets paper oldest known piece paper writing comes ruins chinese dated precisely han garrison abandoned area following nomadic attack 3rd century paper china chief writing han industry upheld private businesses local government agencies domestic construction materials roof tiles bricks han dynasty grey pottery color derived clay superior earlier chinese grey pottery han people use larger chambers longer firing tunnels improved chimney designs han dynasty making grey pottery able reach firing temperatures hard southern chinese pottery dense clay native south southern fired higher temperatures grey pottery han pottery bce fired high temperatures mid western han brown fired low temperature followed green popular states light green known thought exist kingdoms period onwards argues found sites classified argues true created china early song dynasty chinese able reach minimum temperature preferred range techniques blast converts raw iron ore pig iron produce cast iron earliest specimens cast iron found china date 5th century late spring autumn period oldest discovered blast date 3rd century majority date period emperor han established government monopoly iron industry bce discovered iron works sites built date merely recast iron iron ore blast han rarely cast directly permanent instead pig iron cast iron utilized cold blast traveling pipes charge pig iron introduced air traveling pipes hot blast reached chinese civilization lacked han chinese able wrought iron injected oxygen causing han era chinese able convert cast iron pig iron wrought iron steel forge process earliest specimens dating 2nd century bce found near province walls lined bricks bottoms clay wood states fuel han coal mixture coal powder clay use steel iron bronze writes domestic iron tools produced han cheaper cast iron military preferred use wrought iron steel weaponry qualities han dynasty typical bronze sword found period gradually replaced iron sword measuring roughly length ancient dagger axe bronze han soldiers gradually phased iron spears iron traditionally bronze gradually bronze tip iron shaft end han entire solely iron farmers bamboo rammed earth builders disposal iron tools axe hammer knife saw scratch nails common iron found han dynasty homes included cooking belt fire kitchen knives fish hooks mirrors oil lamps bronze iron coin money han copper copper tin bronze agriculture tools methods modern archaeologists unearthed han iron farming tools china north south pick soil harvesting crops depending size han driven pull legged iron seed drill invented 2nd century bce enabled farmers plant seeds precise rows instead casting hand artwork periods use breaking soil appeared china irrigation works agriculture included use water wells artificial ponds dams canals gates alternating fields emperor bce reign grain invented alternating fields system land thin elongated strip land measuring wide long area roughly acres low lying furrows wide straight lines crop seed summer loose soil ridges long furrows gradually fall furrows covering crops protecting wind drought position furrows ridges reversed year process called alternating fields system system allowed crops grow straight lines harvest moisture soil provided stable annual yield harvested crops experimented system right outside capital proved successful sent instructions administrator responsible heads county district hamlet speculates bce role promoting new system rich families owned large heavy iron greatly benefited new system poorer farmers resorted teams men single exhausting work author wrote improved invented needed man control pull seed box drills tool turned soil roughly acres land single day pit fields reign emperor han bce fan wrote manual fan described pit field system system farmland divided small pit dug deep wide good quality mixed soil seeds pit allegedly produced harvested grain pit roughly system require driven fertile land employed sloping supplying water difficult methods farming farming method favored poor require intensive labor large families maintain system rice han farmers region southern china maintained fields growing rice year burn field water rice hand harvest time cut surviving second time system field lays year remain fertile han rice farmers north practiced advanced system system individual plants given intensive care location field separated water field heavily winter crops grown rice situated nearby plant nursery mechanical hydraulic engineering literary sources archaeological evidence evidence han era mechanical engineering comes largely choice writings scholars professional engineers leave detailed records work han scholars little expertise mechanical engineering provided insufficient information technologies described han literary sources provide crucial information written bce belt drive device wound silk fibers invention belt drive crucial step development later technologies song dynasty chain drive spinning wheel engineer mentioned miscellaneous notes official poet hinted writings chinese form pivot support concentric rings allow central rotate axis remaining vertically positioned explicit mention occurred created use allowed burning placed central remain constantly level moved purpose indoor air conditioning set large manually operated fan rotating wheels diameter invented lamp called hill shaped cylindrical lamp lit convection rising hot air currents caused placed spin turn rotated painted paper figures birds animals lamp emperor han came treasury following downfall dynasty found entire miniature musical orchestra tall played mouth organs pulled ropes blew tubes control wrote 2nd century people entertained theatrical plays artificial fish dragons later inventor invented theater moving mechanical powered rotation hidden literary sources known umbrella invented reign simple existed employed sliding joints protracted retracted modern led discovery han artwork portraying absent han literary sources includes handle han pottery tomb models possess known depictions handles operate fans machines machine separate grain chinese later employed handle silk spinning flour drawing water measure distance traveled han era chinese created cart invention depicted han artwork 2nd century detailed written descriptions offered 3rd century wheels device rotated set gears turn forced mechanical figures bang drums alerted travelers distance traveled measured existing specimens found archaeological sites known han era use sliding metal minute measurements han era bear inscriptions exact day year manufactured mentioned han literary sources uses water clock han dynasty chinese developed uses improvement simple tilt hammer device operated foot hydraulic powered trip hammer pounding grain mentioned han dictionary mentioned dictionary written philosophical written poetry writings philosopher china describe square chain pump lift water substances models operated manually foot chain pumps powered horizontal rotated large toothed gears horizontal axis beam primary use lifting water irrigation ditches chain pumps public works programs engineer build lift water pipes provided capital palaces clean water acting administrator invented water powered worked blast iron invention intensive manual labor required work astronomical sphere representing sphere existed china 1st century bce mathematician court provided motive power constant pressure head water clock rotate acted set gears address problem falling pressure head water clock gradually slowed setting additional tank reservoir vessel han court responsible major efforts disaster relief natural disasters earthquakes devastated lives better prepare invented provided instant alert authorities capital earthquake occurred location indicated specific cardinal direction felt capital told court earthquake occurred northwest message came soon earthquake struck northwest modern called device instrument measuring seasonal winds movements earth named thought earthquakes likely caused enormous compression trapped air described book later han frame bronze vessel shape wine diameter decorated scenes mountains animals trigger mechanism inverted book later han calls central column disturbed ground earthquakes located near far away swing strike mobile arms representing directions catch mechanism right angle raise metal dragon heads located exterior metal ball mouth dropped mouth metal arranged like points compass rose indicating direction earthquake book later han states ball fell mouths produced loud noise gained attention observing device accepted idea disturbed inverted contemporary argued inverted pin moving force ground vibrations enter slots expel ball pushing book later han states seven dragon heads subsequently release balls lodged jaws dropped asserted pin locked slot entered instrument reset mathematics astronomy mathematical earliest surviving mathematical ancient china book numbers han bamboo texts dated bce found mathematical text compiled han classic circular paths heaven dated earlier 1st century bce multiple authors contained materials similar described bce school mathematics explicitly mentioned commentary preface added text 3rd century chapters mathematical art title found bronze standard dated speculation material existed earlier books different titles provided detailed commentary 3rd century worth noting context documents excavated han sites contain evidence practical mathematics administrators taxes calculating labor needed public works projects described mathematical innovations presents basic mathematics problems solutions likely handbook day day business transactions affairs government administration contains problems solutions field measurements area proportional exchange rates agricultural rice distribution proportion short width division excess problems found appear later text cases titles exact matches unlike deal problems involving right angle square roots cube roots matrix methods demonstrates significant chinese mathematics writings texts written dialogue form regularly presented problems concerned application mathematics astronomy problem sought determine height sun earth diameter sun instructs wait shadow cast tall han right angle triangle constructed base han equivalent leading sun height sun like gives mathematical proof length lengths sides respectively known west greek mathematician 6th century bce groundbreaking surviving han known book feature negative numbers manuscript india book greek mathematician 3rd century written negative numbers appeared black counting rods positive numbers appeared red counting rods system existed china dynasty bce earliest evidence fraction power inscription standard volume measuring vessel dated mathematician bce book feature means solve represent measurements elimination solve linear known book continued find roots built idea 3rd century increased find cube root yielding answer method scheme named centuries chinese simply value method reach value unknown historians standard measuring vessels dating reign showed known han mathematician han understood area square versus area inscribed circle approximate ratio understood volume cube volume inscribed sphere diameter volume formula found fault realized value diameter inaccurate value taken ratio fix added formula found ratio volume cube inscribed sphere ratio area square inscribed circle formula able approximate square root han mathematician accurate ancient chinese achieve musical tuning theory mathematics musical tuning music theory 2nd century bce compiled scholars patronage bce outlined use tones musical scale bce mathematician music theorist expanded create scale tones realized approximate octaves calculating difference reached value equal temperament duly discovered german mathematician known later prince china flemish region europe simultaneously separately discover mathematical formula equal temperament astronomical observations ancient chinese careful observations heavenly bodies phenomena observations 4th century bce state history acknowledge genuine solar phenomena natural satellites thought west observation precisely dated observation china occurred bce reign emperor han bce silk texts dated later bce sealed tomb manuscript illustrates writings ink drawings roughly different climatic astronomical features including clouds stars silk text site reports times locations rising setting planets night sky years bce han era chinese noted passage seen persia birth bce romans observed close assassination bce bce noted roman historian known discussed han era history books records grand historian book han details given position sky direction moving length time visible color size han era chinese star historian bce monograph officials 2nd century star catalogue featured roughly stars create dimensional representation observations provided sphere ring bce elliptical ring added sphere model added horizon ring ring han han chinese astronomical studies mainly construct revise calendar contrast julian calendar bce calendar west like chinese calendar calendar meaning uses precise movements sun moon time markers year 5th century bce spring autumn period chinese established calendar measured tropical year days like julian calendar rome emperor replaced new calendar bce measured tropical year days lunar month days calendar inaccurate centuries han halted use revived use calendar later set tropical year days calendar value calendar use calendar regulating agricultural practices seasons mark important dates cycle constructed stems associated animal chinese astronomical theory 3rd century commentary describes astronomical theories heavens shaped spherical dome extending earth compares earth central yolk egg heavens shaped sphere earth astronomical theory mentioned model spiritual constitution universe han era chinese believed model immediate solar system greater universe opposed model han era chinese discussed illumination shapes heavenly bodies flat circular rounded spherical wrote 1st century bce han believed sun moon planets spherical like balls bullets wrote moon planets produce light people earth illuminated sun parts illuminated sun dark compared moon mirror light 2nd century drew similar comparison stating sun like fire moon planets like water fire produces light water reflects repeated comment moon illuminated sun left darkness noted sunlight reach moon earth rays lunar eclipse noted solar eclipse occurred moon sun crossed paths block sunlight reaching earth wrote han believed rain fell heavens stars located argued rain fell common theory false agreed theory stated clouds formed water earth clouds disperse rain clouds rain fact essence accurately described water cycle structural engineering public works materials construction timber chief building material han architecture grand palace halls multi story towers multi story residential halls humble wood rapid decay time fire oldest wooden buildings found china temple halls mount date earlier dynasty architectural historian describes han era archaeological remains unreliable han era literary artistic sources historians clues non existent han architecture remains han dynasty architecture ruins brick rammed earth walls including city walls underground tomb walls rammed earth platforms halls stone brick pillar gates scattered roof tiles adorned timber halls sections han era rammed earth great wall exist han frontier ruins thirty beacon towers fortified castles han walls frontier towns forts typically constructed stamped clay bricks instead rammed earth roofs supported wooden pillars addition brick rammed earth mud walls halls actually support roof stone plaster domestic architecture projecting outward built distance falling walls supported decorated designs usually decorated ends roof tiles seen artistic models buildings surviving tile pieces courtyard homes valuable clues han architecture found han artwork models paintings carved stamped bricks discovered tombs sites layout han tombs built like underground houses comparable scenes courtyard houses found tomb bricks dimensional models han homes courtyard area multiple halls slightly elevated connected multi story buildings included main residence halls built halls built intersecting usually carved decorations walls usually produce smooth surface painted han capitals ruins walls han capital stand today height base width modern archaeological surveys proven eastern wall long southern wall long western wall long northern wall long overall total length walls formed roughly square layout southern northern walls sections concerns rough terrain existed southern wall course straight path northern wall city moat wide deep remains wooden bridges discovered moat leading city wall acted terminus points main avenues gatehouse gateway entrances wide han era writers claimed gateway accommodate traffic horse drawn carriages drainage system included dug gates lined bricks form arches water pipes found connected ditches built alongside major streets wall sections platform foundations city lavish imperial palaces remain likewise stone foundations discovered wooden architecture long disappeared sections wall ruins han second capital stand height width base eastern wall long western wall long northern wall long southern wall washed away changed course centuries ago terminus points eastern western walls historians estimate southern wall long overall walled enclosure formed rectangular shape curves like wall gatehouse gateway entrances led major avenues city rammed earth platforms religious stand today outside walled perimeter dedicated worship deities state sacrifices conducted approached long ramps timber halls built lower levels underground tombs 1980s thousand brick stone underground han tombs discovered china earlier chinese tombs dating vertically dug pits lined wooden walls digging tomb sites han workers build vertical pits dig horizontal pits han tombs method tomb sites dug sides mountains walls western han tombs built large hollow bricks smaller non hollow brick type dominated eastern han tomb architecture stone appeared late western han smaller brick type better suited han tomb entrances vaulted chambers roofs underground require supports held place pits use brick han structures unknown layout tombs dug sides mountains typically chamber chambers rear chambers designed imitate complex halls tomb bce province hall window grave goods carriages horses southern separate chamber storage goods northern chamber remains real timber houses roofs erected house stone stone doors rear chamber doors completely stone found han tombs tombs later total monumental brick stone carved pillar gates han dynasty survived found areas han tomb shrine sites formed outer walls usually flanking entry corners walled lack wooden components feature imitation roof tiles mining shafts han tomb brick scenes drilling mining projects shown lifting liquid bamboo pipes surface heat produce salt heated natural gas brought bamboo pipes gas brought surface cause explosion properly mixed oxygen han era chinese built underground chambers gas exhaust pipes drill bit digging operated team men jumping beam boring tool rotated draft animal usually water han dug collecting reach hundreds meters feet beneath earth surface mining shafts dating han dynasty found reach depths hundreds meters feet beneath earth complete underground rooms structured timber frames iron tools left model buildings han era literary references tall towers found capital cities served astronomical religious establishments meant attract favor court discouraged emperor han ascending floors tall towers claiming cause bad luck order conceal enormous built known certain miniature models residential towers found han dynasty tombs completely faithful representations timber towers reveal vital clues lost timber architecture handful existing models multi story towers pre han western han eras bulk hundreds towers found far eastern han period model towers fired piece assembled different pieces create tower duplicate share common features walled courtyard balcony windows floor roof tiles ceiling human figures windows standing door pets dogs courtyard direct pieces evidence suggest miniature tower models faithful representations real life han timber towers tile patterns artistic patterns found circular tiles cap ends miniature models exact matches patterns found real life han roof tiles excavated sites royal palaces tiles original model towers featured come tombs han dynasty towers models han reveal variety building types includes multi story courtyard houses multi story halls walled gate towers mills workshops animal water wells models single story great detail including roofs steps leading basins models windows supports raising ground level han models water wells feature tiny roofs supported beams house rope lifting bucket models featured come tombs han dynasty roads bridges canals order facilitate commerce communication speed process tax collection movement military troops han government sponsored building new roads bridges canal waterways include repairs renovation work built previous state accepting proposal bce emperor commissioned lead project creating extensions nearby terrain elevated main canal large built time canal causing flooding bce project initiated tap irrigation waters requiring new long canal following line han state maintained system protect farmland seasonal floods roadways wooden bridges postal stations relay stations occasionally repaired new facilities established written han authors roads built han metal uncertainty materials speculates rubble gravel roads ranged narrow single horse pass large highways accommodate simultaneous passage horse drawn abreast fortified han roadways built far west near han forces utilized routes traversed north vast network roads fortified passes wooden bridges built rushing steep consolidated han known gallery roads reign emperor roads built connect newly conquered territories far southwest far northeast common bridge types built han wooden beam bridge described literary sources seen carved tomb bricks evidence arch bridges elusive outside south gate claimed date han period built certainly beam bridge artwork relief sculpture han tomb shows arch bridge gradual curve suggesting use bridges entirely confirmed rare references simple suspension bridges han sources mentioned connection travels foreign countries afghanistan demonstrating antiquity invention floating bridges boats secured iron chains built han spanning employed military purposes easily assembled medicine beliefs held han era physicians known modern historians texts medical corpus compiled 3rd 2nd century bce mentioned book later han clear text beliefs phases yang dictated medical decisions assumptions han era chinese believed organ body associated phases metal wood water fire earth channels channels disrupted han medical texts suggest consume edible material associated phases counteract organ prescribed phase restore health example chinese believed heart associated fire phase caused sluggish eat sour food associated wood phase promoted fire han chinese believed pulse diagnosis physician determine organ body emitted vital energy qualities order figure exact disorder patient suffering despite influence theory medicine han texts practical advice proper way perform clinical remove noted symptoms reactions people diseases liver heart lung hour period recognition rhythm explained terms phases essential medical treasures suggest regulated diet rich certain prevent different types disease idea led diet rich treatment major work treatise cold injury miscellaneous disorders contemporary alleged associate physician studied chinese patients surgery created meant fully heal surgery wounds month diagnosis ill woman bore dead removed historical sources rarely practiced mentioning chinese literature appeared gold found tomb han king bce stone carved depictions date wrote allegedly life exercises 2nd century bce medical texts excavated tombs illustrated positions accompanied descriptive titles writes modern physical exercises derived han era map making china preceded han dynasty 4th century bce silk maps found displaying region measured distance timber gathering sites argues considered known economic maps maps roman bce maps han period uncovered modern archaeologists found 2nd century bce silk texts contrast maps han maps found employ diverse use map symbols cover larger terrain display information local populations locations military camps maps discovered shows positions han military garrisons attack bce chinese literature oldest reference map comes year bce assassin present map king ruling later bce behalf instead presenting map pulled dagger unable kill compiled han commented 1st century mentioned use maps governmental provinces districts frontier boundaries locations minerals mining facilities chinese written included information territorial divisions founding cities local products customs describe detail use graduated scale plotted reference grid historians argue literary evidence lost work established geometric reference grid chinese including line book later han cast network coordinates heaven earth basis speculation fueled report records grand historian gigantic raised relief map representing empire located tomb known small raised relief maps created han dynasty rice military officer bce vehicles ancient shipyard discovered dated late 3rd century bce dynasty bce early western han dynasty large platforms capable building wooden ships long wide weight capacity metric tons han shipyard province government operated maritime workshop battle ships assembled widespread use iron tools han dynasty essential crafting vessels southward expansion han dynasty led new trade routes diplomatic contact foreign kingdoms bce emperor conquered modern northern vietnam opened maritime trade southeast_asia indian_ocean foreign merchants brought jade southern sea route group travelers allegedly diplomats likely roman merchants came han court allegedly came southern trade route 1st century proven eastern han miniature models ships found tombs chinese able brave distant waters new steering invention stern mounted rudder came replace efficient steering ancient china home ship designs including layered fortified tower ship meant calm waters lakes river design created 1st century china sailing ship typical square ended bow stern flat hull shaped hull keel solid transverse bulkheads place structural ribs found western chinese lacked rudder attached ship use jaw block tackle differed later european design 12th century written 3rd century author aft sails horse drawn spoke wheeled existed china long han dynasty 1st century bce literary evidence pointed invention painted murals han tomb walls 2nd century use hauling goods throat harness use ancient world placing excessive pressure horses chinese placing wooden horses traces shaft 4th century bce seen han times chinese replaced heavy softer breast seen han stamped bricks carved tomb final stage evolution modern horse collar invented china 5th century period weaponry war machines pivot catapult known traction existed china period evidenced regularly han dynasty besieged common weapon han dynasty small handheld trigger activated lesser extent repeating invented china 6th 5th century bce nomadic able twist slightly horse riding shoot arrows targets official bce deemed chinese superior bow han chinese employed chemical warfare peasant revolt near imperial han forces horse drawn carrying pump lime calcium rebels dispersed instance lit tied tails horses frightened horses rush enemy lines disrupt formations deter pursuits marching infantry riding cavalry han chinese barbed iron balls sharp spikes sticking directions scattered ground pierce feet unaware
Science and technology of the Han dynasty