The Illustrated Encyclopedia of Hindusim vol 2

Yuga
to leave the dog behind. Yudhishthira
flatly refuses to abandon his faithful
companion, even if it means that he will
not go to heaven. The dog then reveals
himself to be the god Dharma in disguise.
The lesson in this story is that
throughout his life Yudhishthira never
allows himself to stray far from righteousness;
even at the end he refuses to
forsake it.
Yuga
A name denoting a unit of cosmic time,
with two possible meanings. According
to traditional belief, time has neither
beginning nor end, but alternates
between cycles of creation and activity,
followed by cessation and quietude.
Each of these cycles lasts for 4.32 billion
years, with the active phase known as
the Day of Brahma, and the quiet phase
the Night of Brahma. In cosmic time,
the Day of Brahma is divided into one
thousand mahayugas (“great cosmic
ages”), each of which lasts for 4.32
million years, and this is one possible
meaning of the word yuga. The more
common use is to refer to a mahayuga’s
four constituent yugas, named the Krta
Yuga, Treta Yuga, Dvapara Yuga, and
Kali Yuga.
785