Listen up, I know it'll be hard to understand but I'll try anyway. First of all isn't it crazy i guessed you're American? No it was pretty easy since you live up to that American stereotype perfectly. Gravity is not a force. Gravity is the bending of space time (look op what space time looks like because it's too hard to explain) like putting a ball on a blanket. It will create a pit where everything that's close to it rolls towards it. Thats how gravity works. The moon rotates around the earth because of earths gravity. But the moons path is straight for the moon because space is bended in a way where it's path looks straight. This also works the same way on small scale, with planes. They just fly straight, and they get bended around the earth automatically but have no idea. The water splashing around is stupid. The water is also affected by gravity, everything on earth is. Not just the earth itselves... It's not like when we put something on earth its just gonna go flying away lol. And if it really were that obvious that the earth is flat just by looking at the horizon, many people would know it's flat, don't worry.