Hans Bethe (German: Bay-ta) (1906-2005) is likely the most important scientist that most people have never heard of. He was the winner of the Nobel Prize in physics in 1967 for his work that explains how the sun produces energy by fusing hydrogen into helium. His paper on this topic won a monetary prize in the mid 1930s. Bethe used this money to buy his mother's furniture from its confiscation by the Nazis so that she could emigrate to the US. Bethe was the lead theoretical physicist on the Manhattan project. Later in life he was a strong critic of nuclear weapons.
In 1997 it was my privilege to interview him for a book I was writing. It was one of the most memorable experiences of my life. His passing last week marks the end of an era. He was greatly beloved by his students and colleagues at Cornell.
Image: Hans Bethe after receiving the Morrison Prize, given in 1940 for his papers explaining the sources of energy production in the sun and other stars. ©Cornell University.