Harold Urey facts for kids
Quick facts for kids
Harold Urey
|
|
|---|---|
Urey in 1934
|
|
| Born |
Harold Clayton Urey
April 29, 1893 Walkerton, Indiana, U.S.
|
| Died | January 5, 1981 (aged 87) La Jolla, California, U.S.
|
| Nationality | American |
| Alma mater |
|
| Known for |
|
| Awards |
|
| Scientific career | |
| Fields | Physical chemistry |
| Institutions |
|
| Doctoral advisor | Gilbert N. Lewis |
| Doctoral students |
|
| Signature | |
 |
|
Harold Clayton Urey (born April 29, 1893 – died January 5, 1981) was an American chemist. He was a physical chemist, meaning he studied how matter behaves and changes. He won the Nobel Prize in Chemistry in 1934 for finding deuterium, also known as "heavy hydrogen."
Urey also played a big part in creating the atom bomb. After the war, he helped develop ideas about how life might have started on Earth from non-living things. He also studied the Moon and its rocks.
Contents
Early Life and Education
Harold Urey was born on April 29, 1893, in Walkerton, Indiana. His father was a teacher and a minister. Harold had a younger brother and sister. When he was six, his father passed away.
Harold went to a small school and finished when he was 14. He then went to high school in Kendallville, Indiana. After graduating in 1911, he became a teacher in Indiana and later in Montana.
In 1914, Urey started studying at the University of Montana. He earned a degree in zoology in 1917.
World War I and Chemistry
When the United States joined World War I, Urey's religious beliefs made him against fighting. A professor suggested he help the war effort as a chemist instead. So, Urey worked at a company in Philadelphia making TNT, which is an explosive.
After the war, he went back to the University of Montana to teach chemistry.
Advanced Studies
To become a university professor, Urey needed a higher degree. In 1921, he began studying for his PhD at the University of California, Berkeley. He studied thermodynamics, which is the study of heat and energy, with Gilbert N. Lewis.
After getting his PhD in 1923, Urey received a special scholarship. This allowed him to study at the Niels Bohr Institute in Copenhagen, Denmark. There, he met many famous scientists like Werner Heisenberg and Wolfgang Pauli. He also met Albert Einstein in Germany.
Family Life
When he returned to the U.S., Urey became a researcher at Johns Hopkins University. He met Frieda Daum and they got married in 1926. They had four children together.
In 1929, Urey became a professor at Columbia University. There, he wrote a book called Atoms, Quanta and Molecules. This was one of the first English books about quantum mechanics.
Discovery of Deuterium
In the 1920s, scientists learned about isotopes. Isotopes are different versions of the same element that have different weights. Scientists thought hydrogen might also have a heavier isotope. They predicted that only about one in 4,500 hydrogen atoms would be this heavier type.
In 1931, Urey decided to look for this heavy hydrogen. He worked with George M. Murphy and Ferdinand Brickwedde. They thought that heavy hydrogen would have a slightly higher boiling point than regular hydrogen.
Finding Heavy Hydrogen
They carefully boiled 5 liters of liquid hydrogen until only 1 milliliter was left. This small amount would have more of the heavy hydrogen. They took this sample to a special lab in Washington, D.C.
When they tested the sample, they saw faint lines on their spectrograph. These lines showed the presence of heavy hydrogen. They named this new isotope deuterium.
In 1934, Urey won the Nobel Prize in Chemistry for discovering deuterium. He chose not to go to the award ceremony because his daughter Mary Alice was being born.
Tracers in Science
Urey and his colleagues also found ways to enrich other elements like carbon, nitrogen, and oxygen with their heavier isotopes. These enriched elements could be used as "tracers." Tracers are like tiny labels that scientists can follow to study chemical reactions in living things. This opened up a whole new way to understand how our bodies work.
Urey also started a science magazine called the Journal of Chemical Physics in 1932. He was its first editor.
World War II and the Atom Bomb
By the time World War II started in 1939, Harold Urey was a leading expert on separating isotopes. This skill became very important for the war effort. Scientists realized that a rare type of uranium, called uranium-235, could be used to create a powerful new weapon: the atom bomb. But first, they needed to separate it from other types of uranium.
The Manhattan Project
Urey joined the top-secret Manhattan Project. This was a huge effort by the United States to build the first atom bomb. Urey was in charge of the group at Columbia University that worked on separating uranium isotopes.
He focused on a method called gaseous diffusion. This process involved turning uranium into a gas and then pushing it through many tiny filters. Each filter would separate a little more of the uranium-235. It was a very difficult challenge, requiring special materials and equipment.
By 1943, Urey had over 700 people working on this project. They faced many problems, like finding materials that wouldn't corrode and building huge plants. The main plant for gaseous diffusion, called K-25, started working in 1945. It became very efficient and helped produce the uranium needed for the atom bomb.
Urey worked very hard on the project. He left in February 1945, just before the plant became fully operational. For his important work, he received the Medal for Merit from the project's director.
After the War
After the war, Urey became a chemistry professor at the University of Chicago. He started studying how isotopes of oxygen could be used to learn about Earth's past climate.
Studying Past Climates
Urey discovered that the ratio of different oxygen isotopes in ancient shells could tell scientists about the temperature of the ocean when the creatures lived. His team studied a 100-million-year-old fossil. They could tell what the summer and winter temperatures were like over four years! This was a new field called Paleoclimatology, the study of Earth's ancient climates.
Urey also believed strongly in peaceful uses for nuclear energy. He spoke out against military control of nuclear power and supported the idea of countries working together for peace.
Cosmochemistry and the Miller–Urey Experiment
Later in his life, Urey helped create a new field called cosmochemistry. This is the study of the chemical makeup of the universe, including planets and stars. He wrote a book called The Planets: Their Origin and Development in 1952.
How Life Might Have Started
Urey thought that Earth's early atmosphere was made of gases like ammonia, methane, and hydrogen. One of his students, Stanley Miller, decided to test this idea. In the famous Miller–Urey experiment, they put these gases, along with water, into a sealed container. They then sent electric sparks through the mixture, like lightning.
To their surprise, this experiment created amino acids. Amino acids are often called the "building blocks of life." This experiment showed how simple chemicals on early Earth might have formed the basic ingredients for life.
Studying the Moon
In 1958, Urey moved to La Jolla, California, to teach at the new University of California, San Diego (UCSD). He helped build the science department there.
He became very interested in space science. When the Apollo 11 mission brought back moon rock samples, Urey was one of the scientists who studied them. He believed that the Moon and Earth came from a common origin, and the moon rocks supported his idea. He even joked that he would volunteer for a one-way mission to the Moon!
Death and Legacy
Harold Urey passed away in La Jolla, California, on January 5, 1981. He is buried in Fairfield Cemetery in Indiana.
Besides the Nobel Prize, Urey received many other awards for his scientific work. These include the Franklin Medal, the National Medal of Science, and the Gold Medal of the Royal Astronomical Society.
Many things have been named in his honor:
- A lunar impact crater called Urey.
- An asteroid named 4716 Urey.
- The H. C. Urey Prize, an award for achievements in planetary science.
- The Harold C. Urey Middle School in Walkerton, Indiana.
- Urey Hall, the chemistry building at UCSD.
- The Harold C. Urey Lecture Hall at the University of Montana.
Urey's daughter, Elizabeth Baranger, also became a well-known physicist.
See also
- Carbonate–silicate cycle
