Come on assholes, back up your fucking spinning globe theory with some numbers. What is the diameter of the shadow cast by the Moon during a total eclipse of the Sun?
I mean it's a bit late to do the maths right now, but the first way I would work out the diameter of the shadow (the umbra, full totality), is by simple geometry.
Diameter of the Sun (about 865,000 miles)
Diameter of the moon (about 2,160 miles)
Distance from the Sun to the Earth (about 93,000,000 miles)
Distance of the Moon from the Earth (239,000 miles)
So now we can draw a pretty diagram, to scale, and work out the diameter of the shadow. Here is a diagram (obviously not to scale) of what I mean:
Edit: Whoops, that's actually a diagram of a lunar eclipse (with the shadow being cast by the Earth), but my method is still valid.
There would me other ways to do this if you don't have a big piece of paper, for example using trigonometry to calculate the angles and distances.
Of course there's not a fixed size, the size of the shadow is related to how close the Moon is to its perigee. But it turns out the diameter of the umbra is about 100 miles.
It's honestly not rocket science. How does this work on a flat Earth again?
