"one side of the world" 用英语表达为 "one hemisphere of the world"。
"hemisphere" 来自希腊语 "hemi-"，意为 "半"，和 "sphaira" 意为 "球体"。所以 "hemisphere" 意为 "半球"。
例句：
The Northern Hemisphere contains the majority of the world's population.
(北半球包含了世界上大多数人口。)
The Southern Hemisphere is home to many unique species of animals.
(南半球是许多独特动物物种的家园。)
The Eastern Hemisphere is where many ancient civipzations developed.
(东半球是许多古代文明发展的地方。)
The Western Hemisphere is home to many diverse cultures.
(西半球是许多多元文化的家园。)