The recent passing of Madeleine L'Engle reminded me of a quiz seventh grade students were given in order to see whether they were at least paying attention during a reading of a chapter from A Wrinkle in Time. I forget the question exactly, but it asked the students about the mechanism that Mrs Who, Which and Whatsit use to travel through the universe. The correct answer was "The fifth dimension."
One student, who was apparently was paying only part attention during class, wrote "The third dimension."
Let's run down the street. "Woo! I'm travelling through the third dimension!"