Thanks for your message. I'm sorry that I elliptically said you
claimed various things that you were only the messenger of. Also, when I wrote
my message yesterday from my office, I was writing from memory of your previous
message (and had not read Ted's), since when I downloaded yesterdays' messages
from home, somehow a glitch occurred so that they were removed from the mailing
spool and so not accessible to me in my office yesterday. At least I have
learned something that I did not realize before, that Ptolemy's system gave a
huge variation in the distance to the moon, which surprises me. If I ever get
time, I'll have to look up why that was done, rather than simply having the
moon go in a circle (perhaps slightly eccentric to account for the actual
elliptic orbit to first order in the eccentricity) around the earth.
The only minor disagreement that I think we still have is with your
statements, "The galilean transforms I posted a couple of days ago show that
the trip causes you to lose one revolution with respect to the stellar sphere
but gain one on the other spheres. Since the ratios were important in that
system, if you believed that the system was real, you would have a causality
problem."
Couldn't one have said the ratios were only important as viewed from a
fixed position on the earth? Surely the assumed causality down through the
spheres was just in their rotation relative to the earth and not in how the
voyagers moved over the surface of the earth. If the voyagers were allowed to
move in a way different from the islanders, then what the voyagers saw would
depend on their motion relative to the earth and would not be the same ratio of
rotation rates seen by the stationary islanders. Since Ptolemy's system gave
primacy to the earth as being fixed, it surely would not have made the
relativistic claim that all observers would see the same ratios, no matter how
they moved.
However, I agree with you that this issue is peripheral to science and
Christianity, and so maybe for the ASA discussion it is hardly worth pursuing.
Best wishes,
Don