Albert Einstein

Thanks to his theory of relativity, Albert Einstein became the most famous scientist of the 20th century. In 1905, while working in a Swiss patent office, Albert Einstein published a paper proposing a "special theory of relativity," a groundbreaking notion which laid the foundation for much of modern physics theory. (The theory included his famous equation E=mc² -- that is, energy is equal to mass times the speed of light squared.) Einstein's work had a profound impact on everything from quantum theory to nuclear power and the atom bomb. He continued to develop and refine his early ideas, and in 1915 published what is known as his general theory of relativity. By 1920 Einstein was internationally renowned; he won the Nobel Prize in 1921, not for relativity but for his 1905 work on the photoelectric effect. In 1933 Einstein moved to Princeton, New Jersey, where he worked at the Institute for Advanced Studies until the end of his life. Einstein's genius is often compared with that of Sir Isaac Newton; in 2000 Time magazine named Einstein the leading figure of the 20th century.