Humans have been experimenting since the days that we first made fire, and it has served us well. Over the ages the sum total of our knowledge has continued to expand and we have learned all kinds of amazing things about the world we live in. However, some of the things we have learned have only been possible because someone first did something absolutely crazy, and some things we know weren’t even that necessary, but they decided they just had to find out what would happen. In this article, we discuss some of the craziest experiments ever performed on human beings (and, in one case, a human’s best friend). Be warned, some of these are rather disturbing.