George Smoot had written to the producers of the show and requested to be featured on the series. Smoot, who received Nobel Prize in Physics in 2006 , is an admitted fan of the series. The scene involving Smoot was shot at the Warner Brothers Studios in Burbank, California on February 18, 2009.
Before Penny opens Sheldon's Japanese puzzle box (a novelty he ordered on the Internet) to retrieve his flash drive, the Dover Publications text Atomic Physics by Nobel Prize-winning physicist Max Born is visible in Sheldon's room amid a stack of books on his dresser.
As the guys board the train, Sheldon tells them everything they are doing wrong. Leonard says to Sheldon that they have been on this train 90 seconds and he had already said 1,000 words. In reality Sheldon only speaks 86 words between boarding the train and Leonard stopping him.