The Equinox

The approaching Equinox represents the product of two separate motions
- daily rotation which causes the day and night cycle and the slow
orbital turning of the Earth which brings the rotational axis in line
with the solar radiation/orbital shadow boundary and causes variations
in the daylight/darkness cycle at all points North and South of the
Equator -

http://www.youtube.com/watch?v=nwTrYVBcx9s]

The specific way the Earth orbits the Sun should be fascinating for
dynamicists and especially as it represents visual affirmation of
Kepler's view of orbital geometry and motion -

http://hubblesite.org/newscenter/arc...999/11/video/b

The original explanation by Copernicus for seasonal variations has
stood for many centuries,I suggest people treat the matter with the
respect it deserves and recognise just how important the modification
is.If they cannot then just leave it be.