universal time coordinates
31relativistic 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 …
32Galilean invariance — or Galilean relativity is a principle of relativity which states that the fundamental laws of physics are the same in all inertial frames. Galileo Galilei first described this principle in 1632 in his Dialogue Concerning the Two Chief World… …
33Relativity 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… …
34Luminiferous aether — The luminiferous aether: it was hypothesised that the Earth moves through a medium of aether that carries light In the late 19th century, luminiferous aether or ether, meaning light bearing aether, was the term used to describe a medium for the… …
35Epoch (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… …
36Declination — For other uses, see Declination (disambiguation). In astronomy, declination (abbrev. dec or δ) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is… …
37Greenwich — This article is about Greenwich in England. For other uses, see Greenwich (disambiguation). Coordinates: 51°28′45″N 0°00′00″E / 51.4791°N 0.0000°E …
38List of radio propagation topics — This is a list of radio propagation terms. NOTOC A a index A index aa index active prominence active prominence region (APR) active region active surge region (ASR) active dark filament (ADF) AE index Air Force Geophysics Laboratory (AFGL) arch… …
39Operation Fishbowl — was a series of high altitude nuclear tests in 1962 that were carried out by the United States as a part of the larger Operation Dominic nuclear test program. Array of rockets with instruments for making scientific measurements of high altitude… …
40Epoch (reference date) — In the fields of chronology and periodization, an epoch means an instant in time chosen as the origin of a particular era. The epoch then serves as a reference point from which time is measured. Time measurement units are counted from the epoch… …
