"Primordial soup" refers to the mixture of organic compounds that existed on early Earth, believed to be the cradle for the origin of life. This soup contained essential elements like carbon, hydrogen, nitrogen, and oxygen, which combined to form simple molecules. Scientists theorize that energy sources, such as lightning or volcanic activity, may have triggered chemical reactions in this environment. The concept of primordial soup is closely associated with the Miller-Urey experiment, conducted in 1953, which simulated early Earth conditions. This experiment demonstrated that amino acids, the building blocks of proteins, could form from simple chemicals, supporting the idea that life could arise from non-living matter.