universal time coordinate
61Classical central-force problem — In classical mechanics, the central force problem is to determine the motion of a particle under the influence of a single central force. A central force is a force that points from the particle directly towards (or directly away from) a fixed… …
62ISO 8601 — Data elements and interchange formats – Information interchange – Representation of dates and times is an international standard covering the exchange of date and time related data. It was issued by the International Organization for… …
63Calendar of 1998 — ▪ 1999 January January 1 At the stroke of the new year, the Russian ruble is worth a thousand times less than before as three zeros are removed from its value; about six new rubles equal one U.S. dollar. Foreign Minister David Levy… …
64Solstice — For other uses, see Solstice (disambiguation). UTC date and time of solstices and equinoxes[1] year Equinox Mar Solstice June Equinox Sept Solstice Dec day time day time day time day time 2004 20 …
65Watch — For other uses, see Watch (disambiguation). Early wrist watch by Waltham, worn by soldiers in World War I (Deutsches Uhrenmuseum, Inv. 47 3352) A watch is a small timepiece, typically worn either on the wrist or attached on a chain and carried in …
6612-hour clock — AM/PM redirects here. For the convenience store chain, see ampm. Clock system 12 hour 24 hour midnight (start of day) 12:00* 00:00 12:59 a.m. 00:59   1:00 a.m. 01:00   2:00 a.m. 02:00 … …
67relativistic mechanics — ▪ physics Introduction science concerned with the motion of bodies whose relative velocities approach the speed of light c, or whose kinetic energies are comparable with the product of their masses m and the square of the velocity of light …
68Theoretical astronomy — Nucleosynthesis Stellar nucleosynthesis Big Bang nucleosynthesis Supernova nucleosynthesis Cosmic ray spallation …
69physical science, principles of — Introduction the procedures and concepts employed by those who study the inorganic world. physical science, like all the natural sciences, is concerned with describing and relating to one another those experiences of the surrounding… …
70History of special relativity — The History of special relativity consists of many theoretical and empirical results of physicists like Hendrik Lorentz and Henri Poincaré, which culminated in the theory of special relativity proposed by Albert Einstein, and subsequent work of… …
