A parameter known as the mass density- that is, how much matter per unit volume is contained in the Universe - determines which of the three possibilities applies to the Universe.
A parameter known as the mass density- that is, how much matter per unit volume is contained in the Universe - determines which of the three possibilities applies to the Universe.
以“质量密度”闻名的一个参数-也就是,在宇宙里含有多少单位体积物质–确定三种可能性哪一种适用于宇宙。