While in Florida we visited Koreshan State Park, a very pleasant hiking location, which is the former site of a utopian commune.
It was founded by some crazy religious group who believed that the earth is a hollow sphere - and we are living on the inside!
If we were in a hollow sphere
I'd expect to look up from here
and get a look at China's Great Wall.
But I don't see that at all.
Instead, I see a clear night sky.
I wonder why.