On Sunday, July 17, 2016 at 5:07:29 AM UTC+1, Davoud wrote:
Sketcher:
Does the sky revolve around the Earth? The answer depends on one's
perspective. A viable argument could be made in support of either a 'yes'
or a 'no' answer with a different set of physical laws supporting each
position. That being said, the physical laws appear to be far simpler if
we assume the 'no' answer to be the correct answer.

True enough for formulation of physical laws, and certainly an
expression of objective reality. As a practical matter, though, I have
to consider that the sky *appears* to revolve around the earth. As seen
by me, my telescope mount stays fixed on the Earth and in the course of
an evening its RA axis rotates to follow the *apparent* motion of
celestial objects as they revolve around the fixed Earth. How can I
prove with just my GEM and my two eyes that it is the Earth that is
revolving, and not the heavens?


Here is what you do, you look at your telescope as it tracks a star in circumpolar motion and realize that it is not a geocentric observation but a homocentric one as any axis on at any latitude will do. In this case the sky is not seen to rotate around the Earth but around you as RA takes no consideration of latitudinal speeds which represent 1037.5 miles per hour at the Equator and zero at the North and South poles.






I'm not mathematically qualified to argue this, but I read once in a
physics book that, given only one's two eyes, it is impossible to
determine whether the Earth rotates on its axis once each day or the
Earth remains fixed while the Sun completes an orbit of the Earth once
each day.


Mathematically qualified indeed !, it takes nothing more than the ability to count in order to fix how many times the planet turns to arrive at the correct conclusions. Empiricists like to say 'time is the joker in the pack' but they are being silly, the real culprit is timekeeping and the fact that a year doesn't constitute an annual circuit within the timekeeping format. With 3 years of 365 days/rotations and 1 year of 366 days/rotations it becomes clear where empiricists find it difficult to handle the foundations of timekeeping based on cyclical references and predictions made within the calendar framework.