Albert Einstein: 1879-1955

From the 1930s on, Einstein focused his scientific energies on the unified field theory, a single equation that would express the relationship between all properties of matter and energy in the universe. Although Einstein was never successful in his quest, his belief remained resolute that the universe is engineered with complete precision. As he once quipped, "Politics are for the moment. Equations are for eternity."

• Person of the Century: Albert Einstein