Selfin, you seem very knowledgeable
Another question or two about gen nav :
Why would twilight be shorter at the equator ? It seems logical to me that in winter, twilight should be longer and shorter in summer : earth's inclination about the ecliptic gives a "pseudo latitude" that's higher in winter and less in summer, providing higher insolation.
It's just as the ecliptic was a fictitious equator.
Does it work like that ?
A question in the database asked the date of the perihelion.
Why would this be of any importance when talking about gen nav ? The same course that states that perihelion/aphelion are of no importance to seasons and that their two values are very close (earth's orbit has very little excentricity)
Thanks