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Life in the Universe

Are we alone in the universe? This question has deep philosophical implications for how we view ourselves as a species. Although science is based upon data, scientists have been unable to resist the urge to speculate on this question in the absence of data. We know that life can develop in the universe by our very presence here – so there is no reason to think that there couldn't be other intelligent life out there. However, we also now know that intelligent life on Earth overcame many obstacles in forming and avoided many dangers to survive. Thus, there are logical arguments to be made on either side of the "are we alone in the universe?" question and a considerable range of opinion exists among scientists and the general public.

Optimistic arguments are often centered around the vastness of the universe. There are roughly 100 billion stars in the Milky Way Galaxy (109) and roughly 100 billion other galaxies in the observable universe. So one can multiply the two for a crude estimate of the number of stars in the universe – 1022 – a large number of places where planets could form. This thinking is creatively expressed in the movie version of Carl Sagan's Contact: "I'd say if it is just us ... seems like an awful waste of space."

Pessimistic arguments are well-expressed in the influential 2000 book entitled Rare Earth: Why Complex Life is Uncommon in the Universe by Peter Ward and Donald Brownlee of the University of Washington. It endeavors to synthesize all current scientific thinking regarding the likelihood of there being other life in the universe. Ward and Brownlee conclude that simple life is likely to be common in the universe because of the high extraterrestial abundance of organic materials and the rapidity with which life arose on the Earth. However, they also argue that complex life is likely to be rare due to the large number of things that had to go just right for it to evolve on Earth.

This laboratory will apply many well-grounded scientific concepts to the problem discussed above. However, users are encouraged to keep in mind that the number of known intelligent civiliations in the universe is ONE until we find another.