Detailed Instructions: Given a text, write a compressed version of it in a single sentence.
Q: The apparently mysterious second law of thermodynamics states that the entropy of a system is either constant or increases. The modern understanding of entropy can be stated roughly with the help of the concept of a 6N-dimensional phase space.
A:
The 2nd law of thermodynamics states that entropy of a system is constant or it increases. Modern understanding can be stated with the help of a 6N-dimensional phase space.