Earth is not in the center of the movements of heavenly bodies, but it
is circling together with the planets around sun - this was a truly
scientific progress made by Aristarchos of Samos and it tells us
something about a frame of reference. The last millenium several
coordinate systems, orientation aids, frames of references, with and
without centers and reference directions, were brought up, and each has
it's merits and is true somehow.
Even Claudius Ptolemaeus in returning against better knowledege to a
geo-centric system is right, as he shows the movements, as they look
like from earth - but the appearance, the shine can betray one: no
planet ever moved in epicycles.(He wanted to sell his astrology of
course).
Now, there's a fresh reference-frame, just right for our millenium to
start with, one i never heard of, not even in the theory, wherein the
speed of propagation of light is an absolutum ( as here is every frame
a frame of an observer in equal rights, it's ego-centric). On 11.
October Sam Wormley wrote:
Once light has left its source and during the finite time of propagation
the target originally aligned with that source moves, aberration can
result.
Whatever theory in physics You are fond of , You should think about
this (and may post some results). Light is independent of it's source
and of course independent of it's observer. With starlight still on
it's way to earth some observers are not even born yet, and when
finally observed, the source might be gone and away. Now, taking any
light, not specially starlight, as a reference for the movement of a
target 8or a source too), that's new.
I agree with Sam and i hope, i'm not misinterpretating his views (i'm
not a physicist).
Regards
Hero
PS. Sam wrote this in the thread "Just a millimeter" here in
sci.physics, which i started with the question:
Will the light-spot of a light-beam or laser-beam of ten meters length
(may be sharpenend with a lens) move throughout half a year of
observation just a millimeter or not ?