palsing wrote:
Ned Latham wrote:

False.

Actually, true.

Ptolemaic Egypt had observatories at Alexandria and Assuan in
the middle of the 3rd century BCE at the latest, because that's when
Eratosthenes calculated the circumference of the Earth, using data
collected from both, along with the known distance between them.

The Large Magellanic Cloud is observable from both and will have been
identified very early in their centuries of service. And that is more
likely than anything else to be Al-Sufi's source. For the Andromeda
Galaxy too.

The Andromeda Galaxy, yes, it can be seen from both Alexandria and
Assuan.

The LMC, no, that is not possible. Alexandria is about 32° north
latitude and Assuan is about 24° north latitude. The LMC is almost
70° south latitude and is therefore well out of range of Alexandria,
and would be about 4° below the horizon from Assuan.

You're right. I inverted the relationship between their latitudes and
Yemen's. Mea culpa. Mea maxima culpa.

Doesn't make an Al-Sufi observation of the LMC likely. What troubles
me is, I can't see Yemen as a likely source, and I can't think of an
alternative.

----snip----

Let's see you bull**** your way out of this claim of yours, Ned...

I'll leave that sort of **** to you, nymshifter.