Up until the late 16th century, everyone "knew" that the sun and planets revolved around the Earth. Up until the late 19th century, epidemic illnesses such as cholera and the plague were "known" to be caused by a poisonous mist filled with particles from rotting things. Up until the early 20th century, the most common procedure performed by surgeons for thousands of years was bloodletting, because we "knew" that blood drained from the body balanced the whacky humors responsible for poor health.
Well alrighty then. But as misinformed as all that may sound now, our predecessors believed these "facts" with the same certainty that we believe that the Earth is round and hot fudge sundaes make us fat. Living in a time of such dazzling science and technology, we stand firmly behind our beliefs … even if so much of what we think we know to be correct is actually wrong. Here are some of the more common misconceptions, ideas that may have started as wives' tales or that came from a faulty study that was later proven wrong. Whatever the case may be, these facts are false.