We can see only one hemisphere at a time on a globe why?

The sun only lights one half of the Earth at a time. because the planet will always obscure some of the night sky from our view. Earth divides it into two equal halves called hemispheres. There are generally considered to be four hemispheres: Northern, Southern, Eastern, and Western.

Ongoing civil wars western roman empire finally collapsed476 c.e. romulus, the last of theroman  emperors in  the west, was overthrown by the germanic leader odoacer, who became the first barbarian to rule in rome. the order that the  roman empire  had brought towestern  europe for 1000 years was no more.