Complex sentence: John Norris Bahcall (1934-2005) was an American astrophysicist, best known for his contributions to the solar neutrino problem, the development of the Hubble Space Telescope and for his leadership and development of the Institute for Advanced Study in Princeton.
Split into simpler sentences: John Norris Bahcall (1934-2005) was an American astrophysicist. He is best known for his contributions to the solar neutrino problem and the development of the Hubble Space Telescope, and for his leadership and development of the Institute for Advanced Study in Princeton.