So what's your 100% proof of the Earth being a solid round perfect sphere/globe that completely shuts down all the flat earth theories?
The fact that if a plane leaves NYC and travels east toward Europe it will eventually pass Europe and make it to Russia/whatever Asian countries might be along that route. Then it's going to eventually get to the west coast of the US and will eventually land back in NYC. All while travelling in the same exact direction.
That is not possible on a flat surface. But is pretty much a guarantee on a sphere.
Tell me a flat surface where u can travel in the same exact direction and eventually land in the same spot you started as opposed to eventually getting to the end of that flat surface without saying "Earth".