> I don't know... everything he said makes great sense.

Then explain this.

When I was in Hawaii (much farther south than where I am) I could observe the sky and see:

- The star Achernar.
- The entirety of the constellation Grus.
- Part of the constellation Pavo.

I live (and am currently located) just a little bit north of the 45th parallel. From here, I cannot see Achernar and Pavo, and I can only see part of Grus. Achernar, Pavo, and the rest of Grus are so far south that they are eternally below the horizon from here.

How do you explain what I saw without assuming that there is at least some degree of curvature in the Earth?

Lucky "Before you ask... Yes, in Hawaii, I was far south enough that I could see the Southern Cross at most times in the year, but I came at the wrong time of year and therefore didn't see it" Wizard