In the special theory of relativity,the simple expression of gravitation in the small region around earth is derived by considering the infinitude of plane with uniform density but actual earth.

• 在狭义相对论范畴内,如果考虑地球周围较小区域内的动力学问题,可以用均匀质量密度的无限大平面产生的重力场替代地球的史瓦西场,从而得到较为简单的重力表达式。