Let's Learn Physics
January 24, 2008
*Diagram showing a Panda and an Antipanda* According to theories pioneered by Richard Feynman, an ordinary panda moving forward in time is equivalent to antipanda(koala) moving backward in time. Thus, the case in which an energetic photon creates a virtual panda/koala pair, which later annihilate each other, can be thought of as a single panda traveling on a closed loop of time.