If I may, I will support this argument for gravity. If one were to refute the existence of one of the four fundamental forces of nature just to conform to a mindset, they are a very arrogant person. If gravity simply doesn't exist, then anything above the ground, such as a plane, would not experience a force perpendicular to itself on a flight path parallel to the ground. If the plane is flying in exactly the prograde direction (the direction of motion/net force) it will still have all of it's passengers feeling this force. There are glasses of water with the water staying inside them, there are people actually not being able to float about the fuselage, and many more examples. Not only does the entire world of aeronautics rely on the fundamental force, everything does, and everyone on this site who refuses to look at a SCIENTIFIC FACT is just simply closed minded.