There you go. That should help. :)
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Although the test remains inconclusive, most scientists believe that non-living, chemical processes in the Martian soil caused the “metabolic” reaction. The Viking experiments showed that while metabolism may be a quality of life, it is not a narrow enough guideline to search for life elsewhere.
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After the nutrient was injected, there was a rapid increase in carbon dioxide (CO2) gas. Because this gas had the radioactive label, scientists at first concluded that organisms in the Martian soil were eating the nutrient and releasing the CO2 as a waste byproduct. However, the Martian soil turned out to have a unique soil chemistry that could produce a metabolic-like reaction.
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At least, that was the idea behind the Viking Lander‘s Labeled Release Experiment, conducted on Mars in 1976. This experiment tested for metabolic clues to life by adding radioactively labeled liquid nutrients to a sample of Martian soil. If these nutrients were consumed by life forms, any gases released as waste byproducts would also be radioactively labeled.
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Living things resist entropy by taking in nutrients. This biochemical process of taking in energy for activities and expelling waste byproducts is known as a “metabolism.” If metabolism is a sign of life, scientists can look for the waste byproducts of a metabolism when searching for life on other worlds.
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But living things, said Shrodinger, are able to postpone this trend. Consider: while you are alive your body maintains its structure, but once you die your body begins to break down through bacterial action and chemical processes. Eventually the atoms of your body are evenly spread out, recycled by the Earth. To die is to submit your body to the entropy of the Universe.
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This law can be seen in a cold glass of water that slowly grows warmer until it is the same temperature as the surrounding air. Because of this trend toward equilibrium, the Universe eventually will have a complete lack of structure, consisting of evenly spread atoms of equal warmth.
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In 1944, the physicist Erwin Shrodinger defined living matter as that which “avoids the decay into equilibrium.” This definition refers to the Second Law of Thermodynamics, which says that entropy always increases. Entropy is often referred to as chaos or disorder, but really it is the spreading out of energy towards a state of uniformity.
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Trying to define life is not just a philosophical exercise. We need to understand what separates living creatures from non-living matter before we can claim to find life elsewhere in the Universe.
