Science fiction on TV can be a good thing — besides being entertaining, it can inspire kids to think of science as a possible future career, says Bad Astronomy's Phil Plait, even when it's not terribly accurate. But when it comes to actual science on TV, like in the news or in documentaries, accuracy is an absolute must. In this video piece, British scientist Brian Cox explains the difference between documentaries and polemics, which are meant to guide or change opinions, and says that while scientists must make TV work for them as a medium, they must also stop worrying about what their audience thinks of their conclusions and just present the science as it is. "Compelling science can make compelling television, but the science must be allowed to speak freely," Plait says.