universal time coordinate
4124-hour clock — 24H redirects here. For the Canadian newspaper chain, see 24H (newspaper). 24 hour clock 12 hour clock 00:00 12:00 a.m. (start of day) 12 midnight 01:00 1:00 a.m. 02:00 2:00 a.m. 03:00 3:00 a.m. 04:00 4:00 a.m. 05:00 …
42Second — This article is about the unit of time. For other uses, see Second (disambiguation). A light flashing approximately once per second. The second (SI unit symbol: s; informal abbreviation: sec) is a unit of measurement of time, and is the… …
43List of astronomy acronyms — This is a compilation of acronyms commonly used in astronomy. Most of the acronyms are drawn from professional astronomy and are used quite frequently in scientific publications. However, a few of these acronyms are frequently used by the general …
44Relativity of simultaneity — thumb|Event B is simultaneous with A in the green reference frame, but it occurredbefore in the blue frame, and will occur later in the red frame.The relativity of simultaneity is the concept that simultaneity is not absolute, but dependent on… …
45Epoch (astronomy) — In astronomy, an epoch is a moment in time used as a reference for the orbital elements of a celestial body. [cite book|last=Soop|first=E. M.|title=Handbook of Geostationary Orbits|publisher=Springer|date=1994|isbn=9780792330547] Typically, the… …
46Prime Meridian — 0° Prime Meridian …
47International Date Line — Date line redirects here. For other uses, see Dateline (disambiguation). The International Date Line around 180° The International Date Line (IDL) is a generally north south imaginary line on the surface of the Earth, passing through the middle… …
48DUT1 — This graph shows the historical evolution of DUT1 between 1985 and 2009. The vertical segments are due to leap seconds. The time correction DUT1 (sometimes also written DUT) is the difference between Universal Time (UT1), which is defined by… …
49Lorentz ether theory — What is now called Lorentz Ether theory ( LET ) has its roots in Hendrik Lorentz s Theory of electrons , which was the final point in the development of the classical aether theories at the end of the 19th and at the beginning of the 20th century …
50Atomic clock — Nuclear clock redirects here. For the clock as a measure for risk of catastrophic destruction, see Doomsday Clock. For a clock updated by radio signals (commonly but inaccurately called an atomic clock ), see Radio clock. For the album by Zion I …
