单词closed universe
网络: 封闭的宇宙；封闭宇宙；闭合宇宙
The closed universe is similar to the surface of a sphere, the size is finite but there is no boundary.
封闭宇宙就好像球体的表面，大小有限但无边。
In a closed universe, there is enough matter to reverse expansion. Eventually, such a universe will collapse on itself.
在封闭的宇宙中，有足够的物质阻止宇宙膨胀，最终这样的宇宙就会崩缩。
A closed universe is a finite universe -- it will only expand to a certain size before collapsing.
封闭的空间是有限的，在膨胀到一定程度后就会崩缩。
If the universe has a positive curvature, it"s a closed universe .
正曲率的宇宙是封闭的宇宙。