One of the layers of false ideas that flat earthers constantly promote is their belief that the force of gravity does not exist. The only reason why they say it doesn’t exist is because the earth is flat. Many flat earthers have made ridiculous video “proofs” where they pour water over a basketball, “fly” a toy airplane over a globe while stating that airplanes must be flying upside down if the earth is a globe, and then they ridicule everyone else who believe the earth is round. So, flat earthers have to dismiss the force of gravity entirely in order to make their theory right. Here is a documentary on gravity that is easy to understand where it shows that gravity does exist, it can be measured mathematically, and its effects can be accurately predicted.