Leonard: Just look at the board.
Sheldon: That's wrong.
Leonard: Oh, no! What should we have done differently?
Sheldon: Well, first of all, you can't use relativistic and non-relativistic vectors in the same equation.
Howard: Told ya. (scoffs) Can you fix it for us?
Sheldon: (sighs) Okay, but this is the last time. (Draws Charlie Brown's face on the squiggle Leonard drew on the board) Nice try, blockheads.