Discussion Overview
The discussion revolves around the variability in the timing of consecutive March equinoxes, exploring potential causes for this irregularity, including gravitational influences and orbital mechanics. Participants analyze data from a specific time range (2001-2100) and reference various sources to understand the underlying factors affecting equinox timing.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant suggests four potential causes for the irregularity in equinox timing: the Earth-Moon barycenter, the circular rotation of the Earth's axis, general relativity precession of Earth's elliptical orbit, and gravitational influences from other planets, particularly Venus and Jupiter.
- Another participant references Wikipedia articles that describe how the equinox is derived from the Sun's ecliptic longitude rather than its declination, indicating that the Moon and planets cause slight variations in Earth's orbit.
- A participant discusses the Earth's axis nutation and its long-term effects, suggesting that it produces a much smaller variation in equinox timing compared to the barycenter effect.
- There is mention of historical observations by Hipparchus regarding the yearly equinox interval and precession, highlighting the complexity of these astronomical phenomena.
- One participant calculates that the Earth's axis nutation could lead to a variation of approximately 33 minutes per year between March equinoxes, but expresses uncertainty about the implications of this finding.
Areas of Agreement / Disagreement
Participants express differing views on the causes of variability in equinox timing, with no consensus reached on which factors are most significant. There is ongoing exploration of the topic, with some participants agreeing on the need for further study of the effects of nutation and other influences.
Contextual Notes
Participants note limitations in their understanding and the complexity of the calculations involved. There are unresolved questions regarding the specific contributions of various factors to the observed variability in equinox timing.