time coordinate
81galactic coordinate — In astronomy, a galactic latitude or longitude, useful for describing the relative positions and motions of components of the Milky Way Galaxy. Galactic latitude is measured in degrees north or south of the plane of the Milky Way. Galactic… …
82Frame of reference — A frame of reference in physics, may refer to a coordinate system or set of axes within which to measure the position, orientation, and other properties of objects in it, or it may refer to an observational reference frame tied to the state of… …
83Spacetime — For other uses of this term, see Spacetime (disambiguation). Two dimensional analogy of spacetime distortion. Matter changes the geometry of spacetime, this (curved) geometry being interpreted as gravity. White lines do not represent the… …
84Lorentz transformation — A visualisation of the Lorentz transformation (full animation). Only one space coordinate is considered. The thin solid lines crossing at right angles depict the time and distance coordinates of an observer at rest with respect to that frame; the …
85Comoving distance — Physical cosmology Universe · Big Bang …
86World line — In physics, the world line of an object is the unique path of that object as it travels through 4 dimensional spacetime.The concept of world line is distinguished from the concept of orbit or trajectory (such as an orbit in space or a trajectory… …
87Introduction to special relativity — In physics, special relativity is a fundamental theory about space and time, developed by Albert Einstein in 1905 [ On the Electrodynamics of Moving Bodies . (fourmilab.ch web site): [http://www.fourmilab.ch/etexts/einstein/specrel/www/… …
88Special relativity — (SR) (also known as the special theory of relativity or STR) is the physical theory of measurement in inertial frames of reference proposed in 1905 by Albert Einstein (after considerable contributions of Hendrik Lorentz and Henri Poincaré) in the …
89nature, philosophy of — Introduction the discipline that investigates substantive issues regarding the actual features of nature as a reality. The discussion here is divided into two parts: the philosophy of physics and the philosophy of biology. In this… …
90Equinox — This article is about the astronomical event when the sun is at zenith over the Equator. For other uses, see Equinox (disambiguation). For the same event happening on other planets and setting up a celestial coordinate system, see Equinox… …
