Don't mean to sound simplistic in the midst of this physics mumbo-jumbo..... but the "accepted" fact is that the Earth is spherically-shaped, even if it's an imperfect sphere. We're not living in the Middle Ages, when people feared falling off the edge. We've got planes and satellites that routinely orbit the Earth. There's literally tons of pictures taken from space (if that premise can be believed and accepted as fact, otherwise we're back to the elaborate studio conspiracy theory). Based on this, the onus is on the "Flat-Earthers" to prove the Earth is flat, not the other way around. And "proving" the Earth is flat will take more than some backyard experiments and trying to equate the behavior of a few gallons of water with the behavior of trillions and trillions of tons of water on a huge planet. Scaling does make a difference in experiments, whether some people want to accept it or not.