On Friday, April 1, 2016 at 3:23:44 PM UTC+1, wrote:
On Friday, April 1, 2016 at 3:13:50 PM UTC+1, oriel36 wrote:
The natural inequality in the total length of the natural noon cycles are from the same cause as the seasons.
The variation in length of the day over a year is because of the elliptical shape of Earth's orbit. This has an influence on the seasons, but we would still have seasons even if the orbit was perfectly circular because of axial tilt.
We have the seasons because of the planet's dual surface rotations to the Sun corresponding to the planet's two distinct day/night cycles.
'Axial tilt' doesn't cause the Sun come into view at the Equinox nor the present twilight at the South pole which will eventually turn to polar night -
http://www.usap.gov/videoclipsandmaps/spwebcam.cfm
This is a real location on the planet with a unique observation where the Sun will be out of view for close to 6 months as that location has now turned through the planet's circle of illumination and into the orbital shadow/umbra of the Earth.
The degree of inclination serves a much more important purpose in defining a planet's climate within a spectrum as the planet's North/South poles turn parallel to the orbital plane and it is this relationship that is crucial for researching climate. Of course the orbital surface rotation and the motion of the polar points are always orthogonal to the circle of illumination and subsequently parallel to the orbital plane -
https://upload.wikimedia.org/wikiped...precession.svg
This 'axial precession' doesn't happen, it was a throwback to the flawed framework inherited from geocentric astronomy and used by the original heliocentric astronomy constructed on using the motion of the Sun through the constellations. Maybe another participant will inform you how this has changed to the line-of-sight motion of the stars behind the central Sun but like much else it is in the archives.
Speaking to somebody who can't associate a planetary sunrise and sunset due to a rotation and this extends to daily rotation can be quite an experience although I wouldn't recommend it.