Looking for an outlet for his ideas, O'Neill wrote a paper titled "The Colonization of Space", and for four years attempted to have it published. He submitted it to several journals and magazines, including "Scientific American" and "Science", only to have it rejected by the reviewers. During this time O'Neill gave lectures on space colonization at Hampshire College, Princeton, and other schools. The Hampshire lecture was facilitated by O'Leary, by now an assistant professor of astronomy and science policy assessment at the institution; in 1976, he joined O'Neill's research group at Princeton. Many students and staff attending the lectures became enthusiastic about the possibility of living in space. Another outlet for O'Neill to explore his ideas was with his children; on walks in the forest they speculated about life in a space colony. His paper finally appeared in the September 1974 issue of "Physics Today". In it, he argued that building space colonies would solve several important problems: