As the former host of MythBusters, this redhead had once devoted her career to challenging the truth of various myths. As the star of its spin-off series, Head Rush, budding Bill Nyes-types get one long commercial-free hour every weekday on the Science Channel with Kari Byron, super cool science celebs, and a mixture of experiments and MythBusters mash-ups that'll make any science geek explode with excitement.