sidereal variations

См. также в других словарях:

• 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… …   Wikipedia

• Modern searches for Lorentz violation — Important motivations for modern searches for Lorentz violation are deviations from Lorentz invariance (and thus special relativity) predicted by some variations of quantum gravity, string theory, and some alternatives to general relativity.… …   Wikipedia

• Hindu chronology — The subject of Hindu chronology divides naturally into three parts: the calendar, the eras, and other reckonings. The Calendar The Hindus have had, from very ancient times, the system of lunisolar cycles, made by the combination of solar years,… …   Wikipedia

• Earth — This article is about the planet. For other uses, see Earth (disambiguation). Earth   …   Wikipedia

• Precession (astronomy) — In astronomy, precession refers to the movement of the rotational axis of a body, such as a planet, with respect to inertial space. In particular, it refers to the precession of the Earth s rotational axis, also called the precession of the… …   Wikipedia

• Astronomy — • Divided into two main branches, astrometry and astrophysics; the former concerned with determining the places of the investigation of the heavenly bodies, the latter, with the investigation of their chemical and physical nature Catholic… …   Catholic encyclopedia

• Orbit of the Moon — Not to be confused with Lunar orbit in the sense of a selenocentric orbit, that is, an orbit around the Moon The Moon completes its orbit around the Earth in approximately 27.3 days (a sidereal month). The Earth and Moon orbit about their… …   Wikipedia

• Solar time — On a prograde planet like the Earth, the sidereal day is shorter than the solar day. At time 1, the Sun and a certain distant …   Wikipedia

• Ethereal being — Water nymph by John Collier, 1923. Ethereal beings, according to some belief systems and occult theories, are mystic entities that usually are not made of ordinary matter. Despite the fact that they are believed to be essentially incorporeal,… …   Wikipedia

• Tropical year — A tropical year (also known as a solar year), for general purposes, is the length of time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox,… …   Wikipedia

• Year — A year (from Old English gēar) is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic. In astronomy, the… …   Wikipedia