How as an individual can I know if the Earth is a sphere or a flat disc? What experiment can I do that doesn't involve trusting information from a 3rd party that would prove what the geometry really is?
http://i.imgur.com/O8IpMmi.jpgThe simpliest thing to do to prove that earth is sphere is by just standing anywhere you want. You being able to stand still is a manifestation of earth being sphere. The force of gravity that pulls you to the center of the earth. Standing on the beach, looking at the horizon where it cuts down the earth, but the water doesn't spill off. Looking on the sun as it rises and sets is a manifestation of earth's geometry being sphere.
