In 1967, he went to United States to study General Relativity theory at Central Studies of Gravitation at Syracuse University under direction of Peter Bergmann and Joshua N. Goldberg whom were among the authoritative experts in general relativity after the inventor, Albert Einstein. Here, Pantur went furthermore studied one of the hottest topics in physics at the time which tried to unify quantum field and general relativity to find quantum gravity theory. It is one of Einstein's dream which had tried but failed to formalize the fourth interaction in the universe into one single theory called Grand Unified Theory. Instead of insisting to work on quantum gravity, Pantur eventually followed the advice of Goldberg to change the subject for his dissertation: to amputate the principle of General Relativity using Poincare Group to find a physical quantity that is conserved in gravitational radiation. These findings confirmed to the Big Bang as a model for the formation of the Universe than the other models. Pantur finished his dissertation with title "Null Tetrad, Formulation of the Equation of Motion in General Relativity" in 1971. Three years later Joshua Goldberg - who produces many important physics treatises published in major journals such as Physical Review D, Journal of Mathematical Physics, and Journal of Geometrical Physics - referred to Pantur's work on his paper, Conservation Equations and Equations of Motion in the Null Formalism. Another works that have citations to Pantur's dissertation including papers by world-renowned physicists, Hermann Bondi and Roger Penrose. A year after completing his dissertation, Pantur back to Bandung in 1972 and taught at the Department of Physics, Bandung Institute of Technology. Pantur is the first Indonesian scientist who studied General Relativity to a doctoral level. Some of his research papers were published in General Relativity and Gravitation, the journal of the International Society on General Relativity and Gravitation. Besides general relativity, he also studies Particle physics. Pantur became a full professor at ITB in 1995. Less than a month after Bergmann died, Silaban retired from ITB in November 2002 at the age of 65. For his contribution to science, especially physics, Freedom Institute - Center of Democracy, Nationalism, and Market Economy Studies awarded him Achmad Bakrie Award in 2009.
