- A whirling mass of liquid or air that spins so quickly that it pulls objects into its empty center.
Season 3, Episode 6 - The Cornhusker Vortex
Aired November 2, 2009
When Leonard feels left out after Penny has her friends over to watch a football game, Leonard decides to learn about the sport. Leonard calls on an unlikely source of football knowledge, Sheldon, who knows all about football from his childhood in Texas. Meanwhile, Howard and Raj's friendship is threatened after Howard causes Raj to lose his prized kite in a kite-fighting match.
Season 3, Episode 12 - The Psychic Vortex
Aired January 11, 2010
Raj enlists Sheldon as his wingman when they attend a university mixer together. When Sheldon and Raj both meet girls at the party, Sheldon's "date" is in for a unique evening as he is oblivious to her advances. Meanwhile, on a double date with Howard and Bernadette, Leonard and Penny argue after he ridicules her belief in psychics.
Season 5, Episode 19 - The Weekend Vortex
Aired March 8, 2012
When the guys decide to spend the weekend playing video games, Sheldon backs out of his plans with Amy to attend her aunt's birthday party.
Season 7, Episode 3 - The Scavenger Vortex
Aired October 3, 2013
When Raj devises a scavenger hunt for the gang, they pair off in uncommon groupings, but the fierce competition causes friction among the friends.