K. A. Tsokos received a B.Sc. degree in Physics and Mathematics from the University of Birmingham in the U.K. and a M.S. and a Ph.D. in Physics from Cornell University in the U.S. He started teaching IB Physics at the Copenhagen International School in 1989 and now teaches IB Physics and Mathematics at the American Community School of Athens. He has served as deputy chief examiner in Physics for the IBO.