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==The 1953 experiment==
==The 1953 experiment==
[[File:MillerUreyExperiment.PNG|300px|thumb|right|The setup of the Miller-Urey Experiment of 1953. It attempted to simulate primitive Earth gases (Methane, Ammonia, Hydrogen, Water Vapor), primitive oceans (Water), and lightning.]]
[[File:MillerUreyExperiment.PNG|300px|thumb|right|The setup of the Miller-Urey Experiment of 1953. It attempted to simulate primitive Earth gases (Methane, Ammonia, Hydrogen, Water Vapor), primitive oceans (Water), and lightning.]]
In the 1920s, Russian scientist A. I. Oparin and British scientist J. B. S. Haldane suggested that the Earth’s primitive atmosphere had "reducing" gases consisted mainly of methane (CH<sub>4</sub>), ammonia (NH<sub>3</sub>), hydrogen (H<sub>2</sub>), and water vapor (H<sub>2</sub>O).<ref name="wells">Jonathan Wells. 2017. Zombie Science: More Icons of Evolution. ISBN: 978-1936599448. 3. Survival of the Fakest</ref> In 1953, Stanley Miller performed an experiment with those exacts same ''reducing'' gases and reported the production of biomolecules from simple gaseous starting materials using an apparatus constructed to simulate the primordial Earth's atmosphere-ocean system. Miller used what he thought was primitive gases that would be available on a primitive earth: 200 mmHg of CH<sub>4</sub>, 100 mmHg of H<sub>2</sub>, 200 mmHg of NH<sub>3</sub> and 200 ml of H<sub>2</sub>O into the equipment. In other words the ratio was 2:1:2:2 for CH<sub>4</sub>:H<sub>2</sub>:NH<sub>3</sub>:H<sub>2</sub>O. Then he subjected this mixture, under reflux, to an electric discharge simulating lightning for a week while the water was simultaneously heated for that time period.<ref name="exp setup">Parker, E. T., Cleaves, J. H., Burton, A. S., Glavin, D. P., Dworkin, J. P., Zhou, M., Bada, J. L., Fernández, F. M. [https://pmc.ncbi.nlm.nih.gov/articles/PMC4089479/ Conducting Miller-Urey Experiments]. J. Vis. Exp. (83), e51039, doi:10.3791/51039 (2014).</ref>
In the 1920s, Russian scientist A. I. Oparin and British scientist J. B. S. Haldane suggested that the Earth’s primitive atmosphere had "reducing" (oxygen poor) gases consisted mainly of methane (CH<sub>4</sub>), ammonia (NH<sub>3</sub>), hydrogen (H<sub>2</sub>), and water vapor (H<sub>2</sub>O).<ref name="wells">Jonathan Wells. 2017. Zombie Science: More Icons of Evolution. ISBN: 978-1936599448. 3. Survival of the Fakest</ref> In 1953, Stanley Miller performed an experiment with those exacts same ''reducing'' gases and reported the production of biomolecules from simple gaseous starting materials using an apparatus constructed to simulate the primordial Earth's atmosphere-ocean system. Miller used what he thought was primitive gases that would be available on a primitive earth: 200 mmHg of CH<sub>4</sub>, 100 mmHg of H<sub>2</sub>, 200 mmHg of NH<sub>3</sub> and 200 ml of H<sub>2</sub>O into the equipment. In other words the ratio was 2:1:2:2 for CH<sub>4</sub>:H<sub>2</sub>:NH<sub>3</sub>:H<sub>2</sub>O. Then he subjected this mixture, under reflux, to an electric discharge simulating lightning for a week while the water was simultaneously heated for that time period.<ref name="exp setup">Parker, E. T., Cleaves, J. H., Burton, A. S., Glavin, D. P., Dworkin, J. P., Zhou, M., Bada, J. L., Fernández, F. M. [https://pmc.ncbi.nlm.nih.gov/articles/PMC4089479/ Conducting Miller-Urey Experiments]. J. Vis. Exp. (83), e51039, doi:10.3791/51039 (2014).</ref>
===Results===
===Results===
==Modern Interpretations==
==Modern Interpretations==
The Miller-Urey experiment assumed an a primitive atmosphere was composed of ''reducing'' gases [e.g. methane (CH<sub>4</sub>), ammonia (NH<sub>3</sub>), hydrogen (H<sub>2</sub>), and water vapor (H<sub>2</sub>O)], but by the 1980s geochemists believes that early earth atmospheres probably had ''neutral'' gases like those emitted by volcanoes [e.g. water vapor (H<sub>2</sub>O), carbon dioxide (CO<sub>2</sub>), and nitrogen (N<sub>2</sub>)] and perhaps some ''reducing'' gases like carbon monoxide (CO). Since hydrogen was a light element, there probably would not have been any in early earth.<ref name="wells" />
The Miller-Urey experiment assumed an a primitive atmosphere was composed of ''reducing'' (oxygen poor) gases [e.g. methane (CH<sub>4</sub>), ammonia (NH<sub>3</sub>), hydrogen (H<sub>2</sub>), and water vapor (H<sub>2</sub>O)], but by the 1980s geochemists believes that early earth atmospheres probably had ''neutral'' gases like those emitted by volcanoes [e.g. water vapor (H<sub>2</sub>O), carbon dioxide (CO<sub>2</sub>), and nitrogen (N<sub>2</sub>)] and perhaps some ''reducing'' gases like carbon monoxide (CO). Since hydrogen was a light element, there probably would not have been any in early earth.<ref name="wells" /> Some scientists believe that early earth atmosphere was similar to earth today.<ref>[https://astrobiology.nasa.gov/news/earths-early-atmosphere-an-update/ Earth's Early Atmosphere: An Update] - NASA</ref>
==See also==
==See also==