Plait, 48, started out as a researcher delving into supernovae, gamma-ray bursts and other mysteries of the universe. But that began to change when he wrote a book titled "Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing 'Hoax.'"

Over the years, he has devoted more and more time to scientific reality checks — in a follow-up book titled "Death From the Skies!"as well as his "Bad Universe" TV documentary series and the Bad Astronomy blog, now in its ninth year.

Bad Astronomy is about much, much more than bad astronomy. Plait takes on those who claim that global warming doesn't exist, that "creation science" needs to be taught in biology class or that kids shouldn't be vaccinated. For a time, he even served as the president of the James Randi Educational Foundation, which takes aim at all sorts of pseudo-scientific silliness.