ଇତିହାସ timekeeping ଇତିହାସ human civilization। ପ୍ରଥମ sundials ancient Egypt atomic ଘଣ୍ଟାଗୁଡ଼ିକ Coordinated Lunar Time, ପ୍ରତିଟି measure ସମୟ ଅନଲଆକ। — navigation, communication, ଅଞ୍ଚଳ, ଏବଂ ବର୍ତ୍ତମାନ exploration।
Ancient Timekeeping
ଶୁରୁ ମାଏ ଜ୍ୟୋତିର୍ବିଦ୍ୟା। Ancient Egyptians ଅଦ୍ୟୁ 3500 BCE, shadow ଭାଗ daylight। Water clocks (clepsydras) ଧୀର ଏବଂ cloudy, ଦଲିଲ 1500 BCE Egypt ଓ।
Moon humanity ପ୍ରଥମ। Word "month" derived "moon," ଏବଂ lunar ବ୍ୟବହୃତ Babylonian, Chinese, Hebrew, ଓ Islamic। Synodic month ଦିନ ସ୍ୱାଭାବିକ ଚଛ planting, religious, ଓ।
Mechanical Clocks ଏବଂ Longitude ସମସ୍ୟା
ମେଦକାଲ clocks 13th-century ଚିଙ୍ଗାନା। ଚାଚା mechanisms ସାଲଳୟ। କିନ୍ତୁ ଅଲୟ ୧୫ ମିନିଟ।
18th century timekeeping longitude। Sea, ଅନେଇ latitude, କିନ୍ତୁ longitude। 1761, John ଚତୁର୍ନିର୍ମାଣ — ଯଥେଷ୍ଟ longitude। Breakthrough oceanic।
Standard Time ଏବଂ Time Zones
Telegraph ଓ railroad, city local। Noon ଏବଂ different। Railroads 19th century। 1884, International Conference Washington Greenwich Prime। ଏହାକୁ ଅଲକ୍ଷ୍ୟ standard।
Atomic Clocks ଓ UTC
Quartz oscillator 1920s fractions। ଜିତିଦିଅରୁ 1955 cesium। Atoms vibrate — cesium-133 9,192,631,770। Modern 300 million।
1972, Coordinated Universal Time। ୪୦୦+ laboratories। Leap occasionally।
GPS ଏବଂ Relativistic ଯୁଗ
GPS, 1995, ପ୍ରଥମ civilian relativistic। Satellites ~20,200 km gravity। Clocks ~45 microseconds ଦ୍ରୁତ (gravitational time dilation), ତଥାପି orbital ~7 microseconds slow (special relativistic)। Net +38।
Relativity, GPS ~10 km। GPS proved relativity ନୁହଁ — ଏହାକୁ।
Coordinated Lunar Time — ଆଗଲ Chapter
April 2024, White House ନିର୍ଦେଶ Coordinated Lunar Time (LTC) — precise timekeeping Earth Moon। Like UTC, LTC atomic, କିନ୍ତୁ ବାକ୍ସ gravity, ଘଟେ 56.02 microseconds ଦ୍ରୁତ।
Sundials atomic Moon — ଅଥଲ୍ଲାସ। Coordinated Lunar Time ଏକଭାଗ ଇତିହାସ ୫,୫୦୦ ବର୍ଷ, ଏବଂ ଏଟ୍ କାରଗଚ exploration।