Letter from Thomas Gold to Dr Allan R Sandage, Mt Wilson and Palomar Observatories, 813 Santa Barbara Street, Pasadena 4, California Wonders if Sandage had left Austin before Gold spoke about the star collision picture. Discusses how colliding objects might account for quasars and how variations in spectral lines might be used to determine whether quasars are a single event or multiple object event. 28 December 1964