Researcher, NASA/Goddard Space Flight Center, U.S.A. He was born in Kavala Greece, on the 1st of May, 1950. He received the B.Sc. in Physics from the Aristotle University of Thessaloniki, Greece (1973), the M.Sc. from the University of Chicago and the Ph.D. (1978) from the same University. He has been NAS/NRC fellow and Research Associate at the University of Maryland. He has been honored with the 3rd prize of the Gravity Foundation for the best essay in Gravity (1976). His scientific interests include Cosmology, Quasar Physics and High Energy Astrophysics and he has published many scientific papers on these matters; in one of them, he showed that the dynamics of scalar fields in the early Universe could change its expansion rate in a way that could resolve the so called Horizon problem, in a process currently known as Cosmological Inflation. He is a member of the International Astronomical Union (IAU), of the American Astronomical Society, of the American Physics Society and a founding member of the Hellenic Astronomical Society (Hel.A.S.). In 2000 he was elected a Corresponding Member of the Academy of Athens, Greece.