Group dynamics - A term that implies that our thoughts and behavior are influenced by the groups of which we are members and, in turn, we influence the thought process and behavior of the group as a whole.
One sidereal day is the time it takes for a star in the sky to come back to the same place in the sky. Because, for all intents and purposes, the sky is âfixedâ, a sidereal day is when the earth rotates 360Â°. A sidereal day is 23 hours 56 minutes and 4.09 seconds long. A sidereal year is the time it takes for the sun to return to the same position with respect to the stars. Due to the precession of the equinoxes the sidereal year is about 20 minutes longer than the tropical year.
Sidereal time is a measure of the position of the Earth in its rotation around its axis, or time measured by the apparent diurnal motion of the vernal equinox, which is very close to, but not identical to, the motion of stars. They differ by the precession of the vernal equinox in right ascension relative to the stars. Earth's sidereal day also differs from its rotation period relative to the background stars by the amount of precession in right ascension during one day (8.4 ms). Its J2000 mean value is 23 h 56 m 4.090 530 833 s.