Entropy is defined as the disorder or chaos within a physical system. It means that energy is not available to do useful work. Left to itself, the entropy of a system cannot decrease. It can only remain the same or increase. To decrease entropy, one has to import energy or do work.
Chaos also denotes a state of disorder.
In Hindu Cosmology, there are four yugas, Satya,Treta, Dwapara & Kali, where Dharma or righteousness is believed to gradually decrease. Adharma or unrighteousness may increase naturally if left unchecked, like entropy mentioned above.
In Bhagavad Gita, Lord Krishna says (Chapter 4, Verse 8)
To protect the virtuous and
To annihilate the wicked and
To re-establish Dharma,
I incarnate from age to age.
In Satya Yuga, 4 incarnations appeared, namely, Matsya, Kurma, Varaha & Narasimha. In Treta Yuga, Rama was the principal incarnation & in Dwapara Yuga, Lord Krishna.
These can be interpreted as the external energy or work agents intervening to reduce entropy (or chaos) to save the world from extinction.
