Miller-Urey experiment
Origin of life · Biology
Study notes
Miller (a 23-year-old graduate student in 1953) ran the experiment for a week — the water turned brown with amino acids and organic sludge, as if the flask were brewing life's soup. Modern re-analyses of his sealed samples found even more amino acids than reported. Critics note early Earth's atmosphere may have been less reducing — but volcanic-gas versions of the experiment still produce organics.