'Big Brain Theory': NASCAR Champion Carl Edwards Serves as Guest Judge (Exclusive Video)

NASCAR champion Carl Edwards drops by The Big Brain Theory: Pure Genius on Wednesday night's episode to judge a car-themed challenge.

Discovery Channel's Kal Penn-hosted series features a group of geniuses living and working together as they push their problem-solving skills to the limit. Each week, they must solve a difficult engineering challenge in only 30 minutes. The creators of the winning designs must rally a team of their rivals to turn their idea into a reality.

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In this week's episode, the four remaining competitors face off in a contest to bring a speeding car to a safe stop. In what is said to be the closest elimination yet, the judges must choose between innovation and simplicity.

Two of the contestants will be eliminated in Wednesday's episode ahead of the show's live finale, airing at 7 p.m. ET/PT on June 19. The winner of the competition will take home $50,000 and a one-year contract with WET, a water-feature design firm whose creations include the Fountains of Bellagio in Las Vegas.

Meanwhile, viewers also can compete for a weekly prize of $5,000 as part of an at-home contest recently announced by producers WET and Pilgrim Studios. Viewers will be able present their own solutions to the show’s “Blueprint Challenge,” put forth at the beginning of each episode to the show’s contestants. More information can be found here.

Edwards was named the 2005 Busch Series Rookie of the Year and won the 2007 NASCAR Busch Series championship.

Big Brain Theory airs at 7 p.m. ET/PT Wednesdays on Discovery Channel.