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December 13, 2010

what is life

with the discovery of the arscenic eating bacteria found in Californias Mono Lake, the question now asked by scientists is what exactly is life? "We don't have a very good definition of life," said researcher Christopher Voigt of the University of California, San Francisco, who works on synthetic biology. "It's a very abstract thing, what we call life, and at what point we say something doesn't have the necessary components versus it does, it just becomes way too murky." Aristotle was the first to "define" life and concluded that life was something that grows and maintains itself. In 1944, Austrian physicist Erwin Schrödinger defined life as that which resists decaying to disorder and equilibrium. But as with most definitions of life their was a loophole. Some have theorized that life is something that which can reproduce itself. Others have said that life can take in energy to move or grow, and release waste. But with so many loopholes it has been hard to nail down a concrete definition of life. "Life, because it is such a complex system of things with so many interacting parts, each of which is essential, it's really tough to make a definition," said biochemist David Deamer of the University of California, Santa Cruz.
"The practical approach to the search for life is to determine what life needs," wrote astrobiologist Chris McKay of NASA's Ames Research Center. That is where the recent arsenic finding comes into play. This discovery opens up the field of new habitats that could hold life. Whether or not this discovery holds weight over time, it's possible that some of scientists' basic assumptions about what life is and what it requires to survive will need to be revised.
Moskowitz, Clara. "Life's Great Mystery: What, Exactly, Is Life? - Technology & Science - Science - LiveScience - Msnbc.com." Breaking News, Weather, Business, Health, Entertainment, Sports, Politics, Travel, Science, Technology, Local, US & World News- Msnbc.com. 12 Dec. 2010. Web. 13 Dec. 2010. .

Posted by joshscha at December 13, 2010 03:36 AM


I think the biggest part of the problem is that our view of what life can be is so limited. With our only source of knowledge of life being that on Earth, we have no perspective. While life would appear to need water, that is only based on knowledge of what life needs on Earth. Trying to set requirements for life based on such a little sample size is like making a scientific law based on an event that only occurred once.

Posted by: nealroth at December 13, 2010 07:32 PM

I think this is a very insightful article you posted. Although there are certain parameters that we have set to define life, I imagine it is difficult for scientists to concretely know what they are looking for in their search for life outside Earth. As scientists are currently doing, it seems that evaluating a planet's potential habitability is the first and most logical step to determining whether life could have or does exist there currently.

Posted by: eswhang at December 14, 2010 12:53 AM

I think most people regard the question 'does life exist' solely through the lens of 'does intelligent life exist'. As we've learned, Mars' soil did show some unique geochemical activity that suggested it posessing qualities of life usually limited to 'living' organisms. Who's to say Mars' surface isn't 'living', meaning, who's to say it hasn't evolved, doesn't have order, doesn't become denser and more widespread as time goes on? Who are we to define what life is?

Posted by: dkaknjo at December 15, 2010 01:36 PM

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