Helmut,
Regarding the occurrence of The Seasons, I think I was mentioning a
position variation relative to a fixed frame defined in a given epoch and due to
Precession e.g., with the Equinoxes shifting West and the Longitude of
Perihelion shifting East the Summer Solstice and Perihelion will eventually
occur at the same time. Precession doesn't effect the occurrence of The Seasons
relative to a calendar which was indeed the original question. I suppose for a
calendar to undergo such a change it would have to be abandoned for a real long
time!
Regards,
Luke Coletti
Sonderegger wrote:
> I am not sure, if I have understood that correctly. Does that mean, that
> summer also after half way of precession (in 13000 years) will be in July in
> the northern hemisphere?
> I think in the northern hemisphere summer is always in July, because the
> beginning of spring is here always when then sun crosses declination of 0
> degree from south to north (= crossing the ecliptic). The places of the
> stars on then sky will change in this 13000 years.
>
> Helmut Sonderegger
