coordinate clock
61Julian calendar — The Julian calendar began in 45 BC (709 AUC) as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year (known at… …
62Theory of relativity — This article is about the scientific concept. For philosophical or sociological theories about relativity, see Relativism. For the silent film, see The Einstein Theory of Relativity. Two dimensional projection of a three dimensional analogy of… …
63Introduction to general relativity — General relativity (GR) is a theory of gravitation that was developed by Albert Einstein between 1907 and 1915. According to general relativity, the observed gravitational attraction between masses results from the warping of space and time by… …
64Lunar distance (navigation) — For the history of the lunar distance method, see History of longitude. Finding Greenwich time while at sea using a lunar distance. The Lunar Distance is the angle between the Moon and a star (or the Sun). The altitudes of the two bodies are used …
65Mental chronometry — For Ian Lowe s book, see Reaction Time (book). Reaction time redirects here. For the biological mechanism, see Reflex. Mental chronometry is the use of response time in perceptual motor tasks to infer the content, duration, and temporal… …
66Dynamical time scale — has two distinct meanings and usages, both related to astronomy: In one use, which occurs in stellar physics, the dynamical time scale is alternatively known as the freefall time scale, and is in general, the length of time over which changes in… …
67OLB5 — was the callsign of a Czech time signal radio station. The station was located at Poděbrady and transmitted time signals originated from the OMA clock at Liblice. The station transmitted in the HF band on 3170 kHz with 1 kW.[1]… …
68Human Era — Holocene era redirects here. For the geological epoch, see Holocene. The Human Era, also known as the Holocene calendar or Holocene era (HE), is a year numbering system that adds exactly 10,000 years to the currently world dominant Anno Domini… …
69Minute — This article is about the unit of time, angle and right ascension. For other uses of the word, see Minute (disambiguation). See also: Minute of arc A minute is a unit of measurement of time or of angle. The minute is a unit of time equal to… …
70Month — For the Egyptian hawk god, see Monthu. A month is a unit of time, used with calendars, which was first used and invented in Mesopotamia, as a natural period related to the motion of the Moon; month and Moon are cognates. The traditional concept… …
