Quote:
Originally Posted by Linus
Speaking of Life on Earth, is there life out there? Do you think it would be as aggressive as Hawking stated:
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Found on wikipedia:
In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the emergence of complex multicellular life (metazoa) on Earth required an improbable combination of astrophysical and geological events and circumstances. The term "Rare Earth" comes from Rare Earth: Why Complex Life Is Uncommon in the Universe (2000), a book by Peter Ward, a geologist and paleontologist, and Donald E. Brownlee, an astronomer and astrobiologist. Their book is the source for much of this article.
The rare earth hypothesis is the contrary of the principle of mediocrity (also called the Copernican principle), advocated by Carl Sagan and Frank Drake, among others.[1] The principle of mediocrity concludes that the Earth is a typical rocky planet in a typical planetary system, located in an unexceptional region of a common barred-spiral galaxy. Hence it is probable that the universe teems with complex life. Ward and Brownlee argue to the contrary: planets, planetary systems, and galactic regions that are as friendly to complex life as are the Earth, the solar system, and our region of the Milky Way are very rare.
http://en.wikipedia.org/wiki/Rare_Earth_hypothesis