What is a flat earther and is it possible for the world to be flat?

A flat earther is someone who believes the world is flat.  They also believe that there is scientific evidence to support this claim.    They do not believe the earth is round, even when we have satellite images of the earth to prove that it is.  Basic laws of physics can also disprove that the earth is flat.  The physics community should respond to these individuals to prevent the propagation of false information.