Ngati muziika ma lokasi awiri omwe ali ndi chidziwitsochi chimodzimodzi — imodzi pa Earth ndi imodzi pa Mwezi — ndipo mudzayang'ana ndi kumapeto kwa tsiku imodzi ya Earth, ma lokasi a Mwezi angayenda patsogolo pa ~56.02 microseconds. Izi sizolakwa za ma lokasi. Izi ndi property yomwe ili mu universe, yomwe yadundulidwa ndi Albert Einstein's general theory of relativity zaka zingapo zapitali.
Gravitational Time Dilation Kufotokozedwa
Einstein's general relativity, yomwe idafalitsa mu 1915, ikulemba gravity osati ngati mphamvu kundi ngati curvature ya spacetime. Zinthu zomwe zimali ndi kufa kwa Earth ndi Mwezi zimapangas spacetime mozungulira zawo, ndipo curvature iyi imapangitsa kuti nthawi ipite motani.
Principle yomwe ili bwino ndi: mphamvu ya gravitational yomwe ndi yaikulu, nthawi ipitako pang'ono. Zomwe izi zimatchedwa gravitational time dilation. Gravity pa Earth ndi ~9.8 m/s², pamene pa Mwezi ndi ~1.62 m/s² — pakupitilizo kuposa kwa imodzi kuchokera ku asanu ndi mmodzi. Chifukwa cha mphamvu ya gravitational pa Mwezi yotsika, spacetime iyitanizo pang'ono, ndipo ma lokasi amayenda mabwinobwino.
Nambala ya 56 Microsecond
Nthawi yeniyeni yomwe ma lokasi pa Mwezi amayenda mabwinobwino imadala pa zoyika zomwe zimayandikira mu gravitational potential pakati pa Earth ndi Mwezi, chonjezera pa zilembedwa zovuta kwa orbital velocity ndi Earth's rotation.
Gravitational blueshift — ma lokasi amayenda mabwinobwino pagravity yotsika — imatopa ~58.7 microseconds pa tsiku. Komabe, orbital velocity ya Mwezi (pamwamba pa 1.022 km/s) imapangitsa time dilation yotsika mu direction yosiyana (velocity-dependent effect kuchokera kwa special relativity), imachepetsa kulosera ndi ~2.7 microseconds pa tsiku. Chigawo cha mawu awa ndi ~56.02 microseconds pa tsiku.
Nambala iyi yayambiritsidwa ndi analysis zosiyanasiyana, zomwe zimaphatikiza ntchito ya NASA's Jet Propulsion Laboratory ndi National Institute of Standards and Technology.
Izi Sizinthu Zomwe Zimali Mu Malingaliro Yokha — Izi Zimayezelwa
Gravitational time dilation ndi imodzi mwa zomwe zayezedwa bwino kwambiri pa physics. GPS satellites, zomwe zimazonthira pamwamba pa 20,200 km altitude komwe gravity ndi yotsika, amayenda patsogolo pa ~45 microseconds pa tsiku kwinanso kwa ground clocks. Ngati tisinthire zomwe izi zimapangitsa, zolakwa za GPS zingankhale kumakwanira pa 10 km pa tsiku.
Physics imodzi iyi yomwe imagwira pa Mwezi. Ngati takhoza kumaso ma lokasi a atomic pa Mwezi, zomwe izi zimapangitsa zimayezerwa kuchokera kwa equations yomwe ndi bwino. Formula ya gravitational time dilation imaperekera zomwe zipezeka kumakutsata pa imodzi ya nthawi mwa trillion.
Chifukwa 56 Microseconds Chimapangitsa Pang'ono
Kwa ntchito za anthu omwe amagwira tsiku ndi tsiku, 56 microseconds siziyamba. Komabe, kwa systems yomwe ndi precise, zimapanga pang'ono:
Ndi mwezi, ma lokasi amayenda patsogolo pa ~1.7 milliseconds. Ndi chaka, kulosera kumakwanira pamwamba pa 20 milliseconds. Kuyambira J2000.0 epoch (Chezamtanda 1, 2000), kulosera kokonkozane kwakonsechi walosera 0.5 seconds.
Kwa navigation, kuwala kumayenda ma kilometers zisanu ndi atatu pa microsecond. Zolakwa za timing za 56 microsecond zimapele kuposedwa kwa ~16 mamita ma zolakwa ya malo pa tsiku. Kwa precision landings yomwe akufunikira mu Artemis missions — zomwe zimulira pa malo omwe ali ndi chidwi pa lunar south pole — kuya kwakonsechi si yokomezeka ngati chakuti.
Umu ndilo zomwe zimapangitsa kuti Coordinated Lunar Time (LTC) zipangidwe: kupereka standard ya nthawi yomwe imawerengetsa kuya kwa relativistic ndi kusimika kwa systems zonse ya Mwezi.