Eighty-one years ago today, November 9, Carl Sagan was born in Brooklyn, New York. Little did he or his parents know, he would leave a lasting impression on science for decades after his death.
Sagan, who died in 1996, was an astronomer, astrophysicist, and an avid and skilled science communicator. He taught at Cornell University, hosted the PBS series "Cosmos: A Personal Voyage," wrote the book "Contact" and many others, and published more than 600 scientific papers.
Though "Cosmos" is now 35 years old, Sagan's wisdom is timeless and the clips (our favorite six and a few extra are below) are still moving.
You can watch most of "Cosmos" on various YouTube channels, or order the DVD from Amazon. For more about Sagan check out his Wikipedia page or one of the many books written about his life.
Sagan helps us understand the fourth dimension.
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Sagan explains the Drake Equation, which is used to estimate the number of alien species there could be in the universe.
http://www.youtube.com/embed/iQvFrQSM9q0
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The eminent scientist discusses apple pie — and the universe needed to make it.
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