Although Crichton is a heroic and unwaveringly loyal character, he is also a mischievously comical one, so much so that he is the primary source of humor for the series. The show derives much of its humor from Crichton's habitual (and extensive) use of Earth-related pop culture references, often used as witty mockery in the face of danger or opponents who, being unfamiliar with the references, are unaware that they are being insulted. Although an occasional reference will provoke curiosity or confusion to his friends, Crichton's fellow shipmates are largely unaffected by these comments because they simply assume them to be native Earth terms that cannot be interpreted by translator microbes and merely extrapolate the meaning from its context. 
John Robert Crichton, Jr./ˈkraɪtən/, played by Ben Browder, is an International Aeronautics and Space Administration (most commonly referred to on the show as IASA)astronaut who, in the opening few minutes of the pilot episode, is accidentally catapulted through a wormhole across the universe, thus setting the scene for the show as a whole. As the only regularly appearing human on the show, he is the main focus and is the main character as he narrates the weekly credits and is the only character to appear in every episode.