Explain Urey Miller's experiment

Stanley Miller and Harold Urey conducted an experiment which demonstrated that several organic compounds could be formed spontaneously by simulating the conditions of Earth's early atmosphere.

They designed an apparatus which held a mix of gases similar to those found in Earth's early atmosphere over a pool of water, representing Earth's early ocean. Electrodes delivered an electric current, simulating lightning, into the gas-filled chamber. After allowing the experiment to run for one week, they analyzed the contents of the liquid pool. They found that several organic amino acids had formed spontaneously from inorganic raw materials. These molecules collected together in the pool of water to form coacervates.

Their experiments, along with considerable geological, biological, and chemical evidence, lends support to the theory that the first life forms arose spontaneously through naturally occurring chemical reactions. However, there are still many sceptics of this theory who remain unconvinced. British astrophysicist, Fred Hoyle, compares the likelihood of life appearing on Earth by chemical reactions "as equivalent to the possibility that a tornado sweeping through a junk-yard might assemble a Boeing 747 from the materials therein".