On Oct 11, 2009, at 4:38 PM, Mauro Lacy wrote:
Mauro Lacy wrote:
...
As I don't read latin, here's fortunately an english version
http://www.webexhibits.org/calendars/year-text-Copernicus.html
I'll post the excerpt when/if I find it.
"The third motion in inclination is consequently required. This
also is
a yearly revolution, but it occurs in the reverse order of the signs,
that is, in the direction opposite to that of the motion of the
center.
These two motions are opposite in direction and nearly equal in
period.
The result is that the earth’s axis and equator, the largest of the
parallels of latitude on it, face almost the same portion of the
heavens, just as if they remained motionless. Meanwhile the sun
seems to
move through the obliquity of the ecliptic with the motion of the
earth’s center, as though this were the center of the universe. Only
remember that, in relation to the sphere of the fixed stars, the
distance between the sun and the earth vanishes from our sight
forthwith."
To me this just means: the sun appears to move on the ecliptic
because the earth moves around the sun in the plane of the ecliptic,
and the stars do not appear to move because the distance to the sun
is miniscule in comparison to the distance to the stars.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
