Jack Smith, professor emeritus of physics at SUNY Stony Brook passed away Sunday. His colleague George Sterman writes " Jack Smith joined the Institute for Theoretical Physics at Stony Brook as research associate in the Institute’s second year, 1967, and he subsequently joined the faculty of the Institute and Department of Physics and Astronomy. Jack was a master of elementary particle theory, whose often-legendary calculations in perturbative quantum chromodynamics contributed mightily toward establishing the contemporary Standard Model, including a landmark 2003 calculation of the Higgs boson cross section. In 2005, he received the President’s Award for Excellence in Scholarship and Creative Activities. After thirty seven years on the faculty, Jack retired in 2006, but kept active as Professor Emeritus. In 2013, he attended the ceremony at which his doctoral advisor, Peter Higgs received the Nobel Prize in Physics. Last September he joined us for the fiftieth anniversary of the C.N. Yang Institute for Theoretical Physics, in whose development he played such an important role. Although his health declined in recent years, even into his last months he was working with former student Eric Laenen and with Bernard de Wit, both of NIKHEF in Amsterdam, on a new edition of his text in quantum field theory. Jack was known as a dedicated teacher and a generous coworker, whom we were proud to count as a colleague. His doctoral students have themselves succeeded in research, education, and in fields beyond. Jack will be missed by his friends at Stony Brook, and across the globe by many in the community of science." Jack was a theoretical physicist of the most un-glamorous sort. His specialty was precision calculations, and he was always trying to improve these calculations by challenging them with data. In many cases, his calculations were superseded after he retired, but they all built on Jack's foundation.