Expanding universe theory

Einstein initially thought the universe was static and added a constant to his equations to support this. This new theory suggested that the equations actually implied the universe was expanding, a concept that later gained significant importance.
 Willem de Sitter Netherlands 1917 Expanding universe theory

Einstein initially thought the universe was static and added a constant to his equations to support this. This new theory suggested that the equations actually implied the universe was expanding, a concept that later gained significant importance.