(cosmology) the theory that the solar system evolved from a hot gaseous nebula
双语例句
用作名词 (n.)
According to the nebular hypothesis, a cloud of interstellar dust and gas underwent gravitational contraction, eventually forming a solar nebula. 根据星云假说，星际尘埃和气体的云块经历重力的收缩后，最后形成太阳星云。
