Isikhathi sokuzilindela isikhathi yisikhathi somuntu umhlaba ukazalwa. Kusukela osundials wokuqala eMisisoni weLodge kuya esekhondi atomic ezilindela Coordinated Lunar Time, inkaso ngayinye yokuzindlela isikhathi ivulele amandla amasha — okuzilindela, ukufowora, sayensi, kanye nenso isikhathi solanga explorer elukhela.
Isikhathi Sokuzilindela Sangaphakathi
Izilumelo zokuqala zesikhathi zibelezwa imiphumela ye-astronomy. I-Ancient Egyptians isebenzisa obelisks kuma-sundials cishe 3500 BCE, ukubalwa inkulumo-langa ukuhlukanisa isikhathi semkholi. Amakhilomethala amanzi (clepsydras) ahlele isikhathi ngemuva kwesikile kanye nezikhathi zezilwandle, nemibuzo eyisizalo 1500 BCE eMisisoni kanye neChina.
ELanga yiyokuqala kwekalendu kumuntu. Igama "month" isukela "moon," kanye nekalendu ye-lunar yakuthwala iyadinyaliwa, Chinese, Hebrew, kanye neIslamic. Synodic month we-29.53 isikhathi ihlinzela inkulumo esikhathi, okukhukhulu okunzuzo, kanye nemiphumela yesilwandle.
Izinkhosikazi Zomekhini Kanye Nompumelelo Wolongitude
Invention ye-mechanical clocks ngo-13th century eYurophu yaguqule umuntu. I-Church bells, enezilawuli zokuphumula, yacela inkulumo yosuku yesikhulelo. Kodwa izinkhosikazi zangaphakathi zaziqonda cishe amaminithi amagabuzele osuku.
Umcubuko omkulu wesikhathi we-18th century wayimpumelelo we-longitude. Ulwandle, umlimi angathola i-latitude kusukela kumaziwe, kodwa i-longitude ibidinga ukolunqumo nge-time esisikholeni somkhela. Ngo-1761, umjikelezo we-John Harrison ye-marine H4 wazuza isikhathi se-5 amasekhondi osuku — okwanele ukuthola i-longitude ngaphandle kwe-nautical emilini. Ibulelelo leli lalinhlinza i-ocean okuzilindela kanye nemidlali yomhlaba.
Isikhathi Esisande Kanye Nezikhathi Zesigaba
Ubhakabhaka i-telegraph kanye nerailway ayinayo, izidlungulu zonke zazinayo isikhathi sayo somkholi. Intambama eBrooklyn yayehluka iminini umuntu kuningiziwe eNew York. Njengoba irailway yaxhumelane neminyana ngo-19th century, ukuyizwa lokhu kusixazululela ekuseni — amakharithi isikhathi etrak eyinayo isigaba esinzuzo.
Ngo-1884, International Meridian Conference eWashington, D.C. yasungula i-Greenwich Meridian umkela wesikhathi kanye nayahlula umhlaba ibe 24 amasigaba esikhathi. Lokulula lumkela wesikhathi wemuhlaba owokuqala, futhi lacele isikhathi somuntu.
Izinkhosikazi Zasekhondi kanye naye-UTC
Ikvartz inkosikazi oscillator, ethuthwakaziwe ngo-1920s, yathuthukisa isikhathi isigaba kusukela nomomente umuntu usuku. Kodwa ibhukhula likube 1955 nge-cesium atomic clock yokuqala esisebenzisele eNational Physical Laboratory eMbreteni.
Izinkhosikazi Ze-atomic zilinganiso isikhathi ngokubala oscillations zama-atoms — cesium-133 atoms vibuthe nge-9,192,631,770 isamasekhondi osigaba umsebenzi, ifrekuwensi ethi isikala umholi atomic ayizakubikelela noma iyongeza umasekhondi ngo-300 yamamilimu iminyaka.
Ngo-1972, i-Coordinated Universal Time (UTC) yasungulwa umkela wesikhathi wemuhlaba owosikelo. I-UTC inhlambalasela Bureau International des Poids et Mesures (BIPM) isebenzisa isikhathi sezikhosikazi atomic ezehlukile kumzuzwane we-80 eminyakeni jikelele. Amasekhondi asomadlula asisindwe ngokusanda ukuze i-UTC ihambekalane nomhlaba okubuyaphakama okungaqengqile.
I-GPS Kanye Nezikhathi Zokubaliselwa
Global Positioning System, eyisindwa ngokusanda ngo-1995, yayinkulumo yokuqala yomuntu edingile i-time okubaliselwa okwenziwa. Izinkhosikazi i-GPS zithatha emhlabeni ngamakhilomethala angamaphethelo, ekuseni ibhukhula engcono. Izinkhosikazi ziyathwala cishe 45 microsecond osuku kukhona umhlaba (gravity okubhaliselwa kwesikhathi), kodwa okunyakulela okwakwazo kukhona 7 microsecond osuku okusesibuku (special relativistic isikhathi okubaliselwa). Umphikisano ngo-+38 microsecond osuku.
Ngaphandle kuqala isixazululo sekhasi, indawo ye-GPS ayozoba nemiskakamelo ngamakhilomethala angamashumi osuku. Okwanikezayo i-GPS yabonisa ukuthi isikhathi sekubaliselwa akukho umqondo kodwa ingeniseli lezandi.
Coordinated Lunar Time — Ikhepu Elitsha
NgApril 2024, i-White House yamemeza ku-NASA ixhumele Coordinated Lunar Time (LTC) — okwandisa isikhathi sesincebanyo kusukela ekuseni umhlaba kuya umhlaba we-luminary. Efani ne-UTC, i-LTC iyothathwa isikhathi se-atomic clocks, kodwa izothuthukisane okubaliselwa okwenziwa weLanga, ekuseni izinkhosikazi zethwala 56.02 microsecond yíya osuku.
Kusukela esundialsini kuya esekhondi atomic kuya elangeni — yinkulumo esikhathini sokuzilindela okuthwala okuthuthuka konke kabusha, futhi iyophakamisa isikhathi esikhambela emhlabeni.