Miller–Urey experiment facts for kids

The Miller and Urey experiment (also called the Urey–Miller experiment) was a famous experiment that showed how organic compounds (like those found in living things) could be made from inorganic ones. They did this by using different forms of energy.

The idea was to copy the conditions that scientists thought were present on the early Earth billions of years ago. It was a test of how life's basic chemicals might have first formed. Specifically, the experiment checked a hypothesis by Alexander Oparin and J.B.S. Haldane. They believed that the early Earth's conditions helped chemical reactions create organic compounds from simpler inorganic ones. This experiment is seen as a classic in the study of the origin of life. Stanley Miller and Harold Urey carried it out in 1952 at the University of Chicago, and published their findings in 1953.

After Miller passed away in 2007, scientists looked at sealed glass containers from his original experiments. They found that Miller's experiments actually produced more than 20 different amino acids. This was much more than what Miller first reported! It's even more than the 20 amino acids that are commonly found in living things today.

New Discoveries About Early Earth

Scientists now have more information about what Earth's atmosphere might have been like billions of years ago. Some evidence suggests it was different from the gases used in the Miller–Urey experiment.

There's a lot of proof of huge volcanic eruptions about 4 billion years ago. These eruptions would have released gases like carbon dioxide, nitrogen, hydrogen sulfide (H₂S), and sulfur dioxide (SO₂) into the air. When scientists have done new experiments using these gases, along with the ones from the original Miller–Urey experiment, they have created an even wider variety of molecules.

Where Did Life's Building Blocks Come From?

It's also important to know that organic compounds, including amino acids, are found in meteorite dust that falls onto Earth. Because of this, scientists studying the origin of life are now also looking at other questions. They want to know how cells and large macromolecules (big molecules like proteins) first formed.

Images for kids

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  How the Miller-Urey experiment was set up.

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  The experiment

See also

In Spanish: Experimento de Miller y Urey para niños