Carl Sagan (1934-1996) Was an astronomer, astrophysicist, cosmologist, author, science popularizer and communicator. His ability to capture the imagination of millions and to explain difficult concepts in understandable terms is a magnificent achievement. Segan was also well known for being an advocate of marijuana and the use of psychedelics. His books and television series have continued to spread knowledge of this universe we live in today. Be insightful, observant and don't stop exploring.