cosmology, comoving distance and proper distance (or physical distance) are two closely related distance measures used by cosmologists to define distances between...
20 KB (2,679 words) - 15:03, 26 June 2025
with time, as comoving distance accounts for the expansion of the universe. Comoving distance is obtained by integrating the proper distances of nearby fundamental...
17 KB (2,536 words) - 16:06, 24 June 2025
tensor that is normalized to use a distance, or that uses geometrized units. Invariant interval Proper time Comoving distance Relativity of simultaneity Moses...
8 KB (1,169 words) - 23:34, 3 September 2021
Observable universe (redirect from Groups and clusters of galaxies)
corresponds to a comoving volume of about 1.22×104 Gpc3 (4.22×105 Gly3 or 3.57×1080 m3). These are distances now (in cosmological time), not distances at the time...
66 KB (6,650 words) - 01:40, 29 June 2025
Faster-than-light (section Proper speeds)
of velocity are also discussed in Comoving and proper distances § Uses of the proper distance). The current distance to this cosmological event horizon...
67 KB (7,979 words) - 03:53, 25 May 2025
Hubble's law (redirect from Hubble distance)
the universe for a given comoving time. D is the proper distance (which can change over time, unlike the comoving distance, which is constant) from the...
132 KB (13,177 words) - 05:27, 15 June 2025
A proper frame, or comoving frame, is a frame of reference that is attached to an object. The object in this frame is stationary within the frame, which...
5 KB (849 words) - 08:15, 6 September 2024
quasar, and Lyman-alpha blob located near the border of the constellations Canes Venatici and Coma Berenices, with the projected comoving distance of approximately...
17 KB (1,840 words) - 21:08, 28 June 2025
also called the cosmological horizon, the comoving horizon, or the cosmic light horizon, is the maximum distance from which light from particles could have...
11 KB (1,570 words) - 19:55, 27 May 2025
largest comoving distance from which light emitted in the past could reach the observer at a given time. For events that occur beyond that distance, light...
29 KB (3,590 words) - 03:24, 22 May 2025
proper distance provides a measurement of how far a galaxy is at a fixed moment in time. At the present time the proper distance equals the comoving distance...
150 KB (9,148 words) - 16:40, 2 July 2025
cosmological horizon, the comoving horizon (in Scott Dodelson's text), or the cosmic light horizon) is the maximum distance from which light from particles...
10 KB (1,561 words) - 10:51, 26 May 2025
Coordinate Time (TCB) is based on a reference frame comoving with the barycenter of the Solar System, and has been defined for use in calculating motion of...
11 KB (1,514 words) - 16:37, 13 November 2023
transformation" for proper reference frames or proper coordinates (German: Eigensystem, Eigenkoordinaten) by using comoving Frenet–Serret tetrads, and applied this...
72 KB (9,055 words) - 09:50, 31 October 2024
called the "comoving transverse distance" DM by the equation DL = (1 + z) DM, where z is the redshift, and the comoving transverse distance is itself equal...
18 KB (1,868 words) - 08:36, 13 June 2025
describe the more realistic scenario of constant proper acceleration, i.e. the acceleration indicated by a comoving accelerometer. This leads to hyperbolic motion...
32 KB (4,446 words) - 02:11, 25 May 2025
frame of reference, as well as for the special case of proper acceleration measured by a comoving accelerometer. Another useful formalism is four-acceleration...
59 KB (7,810 words) - 16:57, 1 April 2025
object at redshift, z {\displaystyle z} , is expressed in terms of the comoving distance, r {\displaystyle r} as: d A = S k ( r ) 1 + z {\displaystyle d_{A}={\frac...
6 KB (1,006 words) - 21:20, 11 January 2025
Rindler coordinates (section Notions of distance)
time T = 0 at position X = 1/α (with α as the constant proper acceleration measured by a comoving accelerometer), then the hyperbolic coordinates are often...
66 KB (7,773 words) - 18:05, 5 February 2025
frame can always be found that is momentarily comoving with the particle. This frame, the momentarily comoving reference frame (MCRF), enables application...
186 KB (24,928 words) - 23:13, 1 July 2025
(z) Earendel: redshift z=6.2; light-travel distance 12.9 Gly (1.22×1023 km; 7.6×1022 mi); comoving distance 28 Gly (2.6×1023 km; 1.6×1023 mi); not including...
27 KB (1,851 words) - 01:33, 9 June 2025
Length contraction (section Known proper length)
a comoving observer; though it "really" exists, i.e. in such a way that it could be demonstrated in principle by physical means by a non-comoving observer...
40 KB (5,073 words) - 16:50, 10 May 2025
V1400 Centauri (section Name and catalogue history)
Centaurus–Lupus subgroup of the Scorpius–Centaurus association, a group of young, comoving stars close to the Sun. The star has been catalogued in as early as the...
30 KB (2,802 words) - 00:12, 20 March 2025
A and the encounter with Earth at D is on the muon's worldline, only a clock comoving with the muon and thus resting in S′ can indicate the proper time...
22 KB (2,853 words) - 03:54, 26 May 2025
Gamma Geminorum (category Stars with proper names)
Shaya, Ed J.; Olling, Rob P. (January 2011), "Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue"...
15 KB (1,218 words) - 04:10, 24 February 2025
coordinates. The radial coordinate is written as a product of a comoving coordinate, r, and a time dependent scale factor R(t). The resulting metric can...
26 KB (3,626 words) - 23:22, 20 June 2025
the proper distance (which can change over time, unlike the comoving distance d C {\displaystyle d_{C}} which is constant and set to today's distance) between...
14 KB (2,059 words) - 00:25, 2 July 2025
Merak (star) (category Stars with proper names)
Shaya, Ed J.; Olling, Rob P. (January 2011), "Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue"...
15 KB (1,361 words) - 20:11, 15 March 2025
two relations indicate that in the comoving frame, all radial distances tend to infinity and tangential distances approaches zero like τ − τ 0 {\displaystyle...
11 KB (1,801 words) - 00:32, 22 January 2025
61 Cygni (category Gliese and GJ objects)
1934, and orbital elements were published. In 1911, Benjamin Boss published data indicating that the 61 Cygni system was a member of a comoving group...
50 KB (5,217 words) - 15:55, 19 June 2025