Guest Stars Michio Kaku as Himself (Michio Kaku, PH.D., Author / Theoretical Physicist) Nick Pope as Himself (Nick Pope, U.K. Ministry of Defense (1985-2006)) Seth Shostak as Himself (Seth Shostak, PH.D., Senior Astronomer, SETI Institute) Avi Loeb as Himself (Avi Loeb, PH.D., Chair of Astronomy, Harvard University)