Leonard: And then a laser will map the reflective surface, and voila. (A floating 3-D image of the pencil appears. Leonard moves it around with his finger)
Penny: Wow. That is amazing.
Leonard: You know, there's a foundational idea in string theory that the whole universe may be a hologram.
Penny: What do you mean? (Leonard flicks a switch. The hologram changes to a view of the planet Earth). Oh, wow!
Leonard: Uh-huh. Well, the holographic principle suggests that what we all experience every day in three dimensions may really (changes projection to the solar system) just be information (changes the projection to the galaxy) on a surface located at the farthest reaches of our cosmos. (Sets the galaxy spinning) So it's possible that our lives are really just acting out a painting on the largest canvas in the universe.
Penny: Sometimes I forget how smart you are.
Leonard: You should visit more often.