If the universe has a positive curvature, it's a closed universe.

正曲率的宇宙是封闭的宇宙。

youdao

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。

youdao

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。

youdao

This is because most cosmologists reckon that the Big Bang could not have generated nearly enough ordinary matter--dark or light--to create a closed universe.

ECONOMIST: The dark side of cosmology

It is a closed social network in a universe designed to be open.

FORBES: The Importance of Facebook's Graph Search

It was my editorial duty to be sure that every story didn't end with the writer sipping sundowners (those writers...) by a campfire somewhere, pondering the universe as the African night closed around.

FORBES: Editor's Note