Despite some atheist rhetoric (just ignore it), this video exposes "flat earth" retardation.
It's too bad that some people think it's effective to be insulting.
Flat-earthers mean well, they're just misinformed. But some of them really don't want to know or think about the basics of physics or material sciences which are demonstrable in an experimental scenario. Anyone who studies a science major in college has to pass the basic physics classes, and if they go through the whole course they have to successfully complete calculus based physics. That means that they won't be coming out of that class with a passing grade and then proceed to make arguments for a flat earth or against the existence of gravity.
The video above contains some good, simple geodesic and geometric calculations, that is, ones that don't require integration or differentials. Even so, it seems unlikely that any of the flat-earthers even here on CI are going to press the keys on their trig calculator (if they even have one) to see that these distances are computed correctly.
Consequently, and perhaps largely due to the derisive language employed therein, they will never achieve a significant degree of comprehension of the examples given, especially the one showing the calculated arc distance vs. actual distance traveled over Australia from east to west.
In other words, the video shows some good stuff in it but they do it without regard to common decency and they throw out any polite decorum like the baby with the bathwater.
As an example of keeping some decorum alive in the discussion, this guy seems to show some promise. He's just getting started so he might have a lot more to offer in the future: