Discussion Overview
The discussion centers on the choice of the Schwarzschild metric over the FLRW metric for deriving the deflection of light by the sun and the precession of perihelia of planets. It explores the implications of using these metrics given the non-isotropic and non-static nature of the solar system.
Discussion Character
- Technical explanation, Conceptual clarification, Debate/contested
Main Points Raised
- Some participants question why the Schwarzschild metric is preferred over the FLRW metric for specific calculations related to light deflection and planetary motion.
- Others argue that the FLRW metric assumes a uniformly distributed matter, which is not a good approximation for the solar system scale.
- It is noted that while the solar system is not isotropic or static, the Schwarzschild metric still provides a good approximation due to the Sun's significant mass relative to the total mass of the solar system.
- A participant raises a question about the terminology of "precession of perihelia," specifically why the nearest distance from the sun is used for calculations instead of the aphelion distance.
- Another participant responds that the use of perihelion distance is simply common practice in astronomy.
Areas of Agreement / Disagreement
Participants express varying views on the appropriateness of the Schwarzschild metric versus the FLRW metric, indicating that multiple competing perspectives remain regarding the best approach for these calculations.
Contextual Notes
Participants acknowledge limitations in the applicability of the Schwarzschild metric due to the solar system's non-isotropic and non-static characteristics, but do not resolve the implications of these limitations.