Sam Ruben facts for kids

Samuel Ruben was an American chemist who made a very important discovery. In 1940, he worked with Martin Kamen to find a way to create carbon-14. Carbon-14 is a special type of isotope (a version of an atom) that has been very useful in science.

Early Life and Education

Samuel Ruben was born Charles Rubenstein on November 5, 1913. His family officially shortened their last name to Ruben in 1930. When he was young, Sam became friends with his neighbor, the famous boxer Jack Dempsey. He even joined a local boxing club.

Later, his family moved to Berkeley, California. There, Sam became a successful basketball player at Berkeley High School. After high school, he studied Chemistry at the University of California, Berkeley. He earned his first degree, a Bachelor of Science, and then continued his studies. In 1938, he received his Ph.D. in physical chemistry. Soon after, he started teaching in the Chemistry Department at the same university.

Discovering Carbon-14

Ruben worked with another scientist named Martin Kamen. Kamen was a researcher in chemistry and nuclear physics at the Berkeley Radiation Laboratory. They wanted to understand how plants use carbon during photosynthesis. Photosynthesis is the process where plants turn sunlight into energy.

Between 1938 and 1942, Ruben and Kamen did many experiments. They used a short-lived radioactive isotope called carbon-11. This helped them study how carbon moved through plants. Their work suggested that plants could process carbon dioxide even in the dark. This idea was different from what many scientists believed at the time.

Experiments with Radioactive Carbon

Ruben and Kamen used a machine called a cyclotron to make carbon-11. They worked with scientists from different fields, like botany (the study of plants) and microbiology (the study of tiny living things). They wanted to see how carbon dioxide moved in plants, algae, and bacteria.

Their early results were a bit confusing. But their experiments sparked a lot of interest around the world. This led to a big change in how scientists studied biochemistry (the chemistry of living things) and medicine.

Ruben also did experiments using "heavy water" to show that the oxygen gas released during photosynthesis actually comes from water.

Finding the Long-Lived Isotope

Scientists thought there might be a "long-lived radioactive carbon isotope." Ruben and Kamen tried different ways to find this carbon-14 isotope. After several tries, Kamen collected the results from a long experiment using the cyclotron.

On February 27, 1940, Ruben proved that the radioactivity they found was indeed from carbon-14. This was a huge breakthrough!

Impact of Carbon-14

Using carbon-14 in experiments was difficult at first. It was hard to measure its weak radiation. Also, World War II began, which stopped the production of the isotope.

In 1942, Ruben was asked to work on research related to the war. He had to leave his work on photosynthesis. He knew how important carbon-14 could be. He gave his carbon-14 samples to another chemistry professor, Andrew Benson. Benson then used it to continue studying how plants use carbon.

Years later, in 1949, a chemist named Willard Libby used carbon-14 to invent radiocarbon dating. This method helps scientists figure out the age of ancient objects and fossils.

Later Life and Family

During World War II, Sam Ruben researched how phosgene gas worked. Phosgene was a poisonous gas. He studied how it reacted with lung proteins.

Sadly, Sam Ruben died on September 28, 1943. This happened after an accident in his laboratory the day before.

Sam Ruben married Helena Collins West, who was also a chemistry student. They got married on September 28, 1935. They had three children: Dana West Ruben, George Collins Ruben, and Connie Mae Ruben Fatt. George later became a professor at Dartmouth College.

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