Tuesday, April 4, 2017
More on the Shifted Time of Spring Equinox
The formula to the shift in time of the Spring Equinox could be clarified somewhat. The Sun has a mean position and mean path. The Moon and other bodies can shift the Earth's position a little and this will affect the apparent position of the Sun which travels parallel to and at the same speed as the mean Sun. So for some arbitrary deviation, δ, relative to the mean position we can calculate the extra distance the Sun needs to travel in order to cross the Celestial Equator and the maximum value.
Note that the error is magnified by small angles of inclination for the path. As stated previously the maximum error is for θ = 0 or a deviation perpendicular to the plane of the Celestial Equator. Of course when the deviated position is above the Celestial Equator the Sun will cross before the Mean Sun does.