Extraordinary claims require extraordinary evidence. Bill Nye demonstrates the difference between real science and pseudoscience. Science is the process of testing claims. Any claim that can't be tested is based in pseudoscience. What's considered a pseudoscience? Things like magic, the use of psychic, tales of bigfoot and UFOs -- none of these can be scientifically tested.
Bill Nye: The Science Guy - Pseudoscience (Full Episode)
Video by Disney 1996