precession of the equinoxes

Thân thiện

The diagram illustrates the precession of the equinoxes over a 26,000-year cycle.

Definition

1. Noun:
   • A slow westward shift of the equinoxes along the plane of the ecliptic: This is a specific astronomical phenomenon describing the gradual change in the position of the equinoxes (the two points where the celestial equator and the ecliptic intersect) relative to the background stars. This shift is caused by the precession (a slow, conical wobble) of the Earth's axis of rotation.

Usage

• The term "precession of the equinoxes" is used in astronomy, astrophysics, and related scientific fields to describe a long-term cycle affecting celestial coordinates and calendars.
• It is typically used in singular form as a specific, named phenomenon.

Examples

• Noun:
  • The precession of the equinoxes has a cycle of approximately 26,000 years.
  • Ancient astronomers may have been aware of the slow effects of the precession of the equinoxes.
  • Calculating the precise rate of the precession of the equinoxes is important for accurate star charts.

Advanced Usage

• In historical/archaeological context: The concept is sometimes discussed in relation to the alignment of ancient monuments or the interpretation of historical star catalogs.
  • Some theories suggest the Great Sphinx was aligned with Leo during a different age due to the precession of the equinoxes.

Variants and Related Words

• Precession (n): The general physical phenomenon of a rotating object's axis slowly tracing out a cone. "The precession of the equinoxes" is the most famous consequence of the Earth's axial precession.
• Axial precession (n): A more technical term for the wobble of the Earth's rotational axis itself, which is the direct cause of the precession of the equinoxes.

Synonyms

• There are no direct single-word synonyms for this specific multi-word astronomical term. The phrase itself is the precise technical term. Related conceptual descriptions include:
  • The westward motion of the equinoxes.
  • The equinoctial precession.

Related Phrases

• The Great Year: A term sometimes used for the complete cycle of the precession of the equinoxes.
• Astrological Age (e.g., Age of Aquarius): A period of roughly 2,150 years defined by which zodiac constellation the Sun appears in at the vernal equinox, a division of the precessional cycle.

Học thuật

Noun

1. a slow westward shift of the equinoxes along the plane of the ecliptic caused by precession of the Earth's axis of rotation