Bad science (also known as junk science, science myths or science misconceptions) consists of common misconceptions passed on from parents, teachers and inaccurate text books. As American scientist Stephen Jay Gould said, "The most erroneous stories are those we think we know best and therefore never scrutinize or question."
Phil Plait is an astronomer who loves wagging his virtual finger at inaccurate astronomy wherever he finds it. My favorites sections are Misconceptions and Movies. Misconceptions debunks common ideas such as "The sky is blue because it reflects light from the oceans" and "Water spins down a drain one way in the northern hemisphere and the other way in the southern hemisphere." In the movie section, Plait includes spoiler and non-spoiler critiques for many science fiction films.
Alistar B. Fraser is an Emeritus Professor of Meteorology at Pennsylvania State University, and the creator of both Bad Science and Bad Meteorology. Both sites are dedicated to exposing "well understood phenomena which are persistently presented incorrectly by teachers and writers." For example, despite common representation as teardrop shaped, raindrops are spherical or shaped like hamburger buns.
Think you know movie ratings? Visit Stupid Movie Physics to learn about GP (good physics), PGP (pretty good physics) and PGP-13 (" Children under 13 might be tricked into thinking the physics were pretty good; parental guidance is suggested!") This fun site rates movies, and explains generic physics mistakes commonly found in movies. "Ever notice how cars in movies always burst into flames the instant they collide with anything? Our favorite is when a car falling from a high place explodes the instant before it hits the ground."
A common theme running through this week's batch of sites is how difficult it is to replace a falsehood that was learned and reinforced early. The lies corrected here are really pervasive; I was surprised by a few of them. They include the uniqueness of snow flakes, taste map of the tongue, twenty-four hour rotation of the earth, and crediting Columbus with discovering that the earth is round.
Science Myths is another site dedicated to grade-school science misconceptions, with a focus on physics and electricity. In addition to listing and debunking dozens of myths (was Ben Franklin's kite really hit by lightning?) it has related quotations, a huge links section, and links to news articles about textbook errors.