What experiment aimed to recreate the conditions of the Earth's primitive ocean under a reducing atmosphere?

The Miller-Urey experiment was a groundbreaking study conducted in the early 1950s that aimed to explore the origins of life by simulating the conditions thought to be present on the early Earth. Researchers Stanley Miller and Harold Urey designed an apparatus that mimicked the Earth's primitive ocean under a reducing atmosphere, which is characterized by the absence of free oxygen and the presence of gases such as methane, ammonia, and hydrogen.

In their setup, they heated water to produce vapor, which then mixed with these gases in a closed system. An electrical discharge, simulating lightning, was used to provide energy for chemical reactions to occur. After running the experiment for a week, they analyzed the resulting liquid and discovered the formation of amino acids, the building blocks of proteins. This pivotal experiment provided key evidence that organic molecules necessary for life could form spontaneously under the right conditions.

The experiment was significant because it supported the hypothesis of abiogenesis—the idea that life could originate from non-living matter—by demonstrating that simple organic compounds could form in a prebiotic environment.