Neil degrasse Tyson Are We Alone

www.myspace.com In the search for extraterrestrial intelligence (SETI), researchers differentiate between advanced and non-advanced civilizations. An advanced civilization is defined as one with the ability to conduct interstellar communication — to send electromagnetic signals through space. Using this definition, human civilization only became advanced within the past century, when local communication such as radio and television broadcasts began to be transmitted to interstellar space.

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