1917年,也就是爱因斯坦创立广义相对论的第二年,为了解释宇宙的稳恒态性问题,爱因斯坦和荷兰物理学家德西特各自独立进行此项研究。德西特发现,引力场方程的宇宙解是动态的而不是静态的,也就是说宇宙要么膨胀,要么收缩。但由于物理直觉的偏见和数学运算的失误,爱因斯坦决不放弃静态宇宙的概念。1922年,美国学者弗里德曼求出了这个方程的另—个 In 1917, the second year after Einstein founded general theory of relativity, Einstein and Dutch physicist Desch independently conducted this study in order to explain the issue of the steady state of the universe. De Sitter found that the universal solution to the gravitational field equation is dynamic rather than static, which means that the universe either expands or contracts. However, Einstein never gave up the concept of a static universe because of physical instinctual prejudices and math mistakes. In 1922, American scholar Friedman found another one of this equation