Run it, twiddle the sliders, say "ooh" and "aah". Pretend not to notice how inaccurate the map is.
Hm, I unshared this a long time ago because it had stopped working, but now it is working again. I guess it was a Scratch bug which has been fixed? It looks like @weegaweek has made a similar project: https://scratch.mit.edu/projects/337578866/ If you like this you should look at that one too. I'm not sure if I saw that project before making this one, it is possible that I saw that one and got inspiration from it. But this is all my own code, not a remix or re-work of any other project. This exposes my amazing ignorance of geography. But the point was getting the math right to project a 2D rectangular map onto a sphere. Maybe I'll fix the map later? Or maybe some kind remixer will do that for me. It turns out that the math is not that hard, it is mostly just a lot of sine and cosine.
