Addressing this one paragraph, just to show you how wrong your actually are. It is NOT true that a flat earth was "scientific fact" in the past. It was, rather, religious belief. The fact of the matter is that intelligent studiers of nature, going all the way back to the ancient Greeks, were quite comfortable with a ball-shaped earth.
For example, in his book On the Heavens, Aristotle wrote: "Again, our observations of the stars make it evident, not only that the Earth is circular, but also that it is a circle of no great size. For quite a small change of position to south or north causes a manifest alteration of the horizon."
In other words, you see different sets of stars in the night sky depending on where you are. The sky over the northern hemisphere is not the same as the sky over the southern hemisphere. If the Earth was flat, then at any given time we would all see the same stars, and we don't.
Using the same sort of idea, another Greek thinker and mathematician, Eratosthenes, went further and managed to measure the Earth's circumference. He discovered that at noon in one Egyptian city, the Sun was directly overhead, whereas in a different city further north, the Sun did not rise quite so high. Eratosthenes knew the distance between the two cities, measured how high in the sky the Sun rose to in each at the same time, then did some trigonometry. His method was crude, but his answer was in the right ballpark.
And for the record, he Eratosthenes could not have even begun to think as he did unless he was certain first and foremast that the earth was a ball!
People were not executed by science for believing otherwise, but rather by the Church -- all, no doubt, out of the highest "Christian Love."
