A spherically symmetric structure of the earth has been assumed . 人们把地球的构造假设为球状对称。
Einstein s original cosmological model , introduced by him in 1917 , was a static , homogeneous model with spherical geometry 爱恩斯坦在1917年发表的宇宙模型是一个静态均匀及具有球状对称的宇宙。
Because the forces that are supposed to drive off mass from dying stars are spherically symmetrical , astronomers before the 1980s thought of planetary nebulae as expanding spherical bubbles [ see “ planetary nebulae , ” by martha and william liller ; scientific american , april 1963 ] 由于原本认为,从垂死恒星表面将质量载运出来的作用力具有球状对称性, 1980年代以前的天文学家,把行星状星云想像成膨胀的球形泡泡(请参见延伸阅读1 ) 。