In 1879, Albert Einstein was born in Ulm, Germany. He completed his Ph.D. at the University of Zurich by 1909. His 1905 paper explaining the photoelectric effect, the basis of electronics, earned him the Nobel Prize in 1921. His first paper on Special Relativity Theory, also published in 1905, changed the world. After the rise of the Nazi party, Einstein made Princeton his permanent home, becoming a U.S. citizen in 1940. Einstein, a pacifist during World War I, stayed a firm proponent of social justice and responsibility. He chaired the Emergency Committee of Atomic Scientists, which organized to alert the public to the dangers of atomic warfare.