Sheldon said he's been dreaming of going to the hadron collider since he was 9 but wasn't the collider first conceived in around 2010.
Goof: After Leonard tells the gang about him going to Switzerland, Sheldon gets excited and says that he'll start packing. Given that he always asks someone to drive him he couldn't possibly have gone home to pack.
Penny: (after Sheldon cited from Leonard and their roommate-agreement) You actually put that in an agreement?
Leonard: Yeah, we also put in what happens if one of us wins a MacArthur Grant, or if one of us gets superpowers, or if one of us is bitten by a zombie.
Sheldon: He can't kill me, even if I turn.
Penny: Is there anything in there about what if one of you gets a girlfriend?
Sheldon: No, that seemed a little far-fetched.
Sheldon: Given that Saint Valentine was a 3rd century Roman priest who was stoned and beheaded, wouldn't a more appropriate celebration of the evening be taking one's steady gal to witness a brutal murder?
This episode's end titles has Chuck Lorre's Vanity Card #277, detailing how Belarus television has a blatant copy of the show called The Theorists that just uses BBT scripts translated into Russian, and since the station is government owned, not much can be done to stop it.
The Italian episode title is "La grande collisione degli Adroni". The German title is "Freiflug nach Genf", meaning "Free Flight to Genava". The French title is "Le Grand Collisionneur", meaning "The Large Hadron Collider".
Music: Sheldon plays Edvard Grieg's Morning Mood (from his Peer Gynt Suite No. 1, op. 46) with his recorder.
International Airdates: Latin America: April 6, 2010 on Warner Channel; Australia: April 26, 2010 on Channel 9; United Kingdom: June 3, 2010 on E4; Finland: December 13, 2010 on Sub; Czech Republic: December 27, 2010 on Prima COOL; Turkey: January 10, 2011 on CNBC-e; Slovakia: November 7, 2011 on Markiza
After Sheldon claims that Leonard has "betrayed" him, he gives him 30 pieces of silverware on a tray in the cafeteria at work. This is a reference/allusion to the 30 pieces of silver that Judas was given to betray Jesus Christ.