the second law of thermodynamics states that the entropy of the universe must always do what
Second law of thermodynamics The second law of thermodynamics states that the total entropy can never decrease over time for an isolated system, that is, in a system which neither energy nor matter can enter nor leave. The total entropy can remain constant in ideal cases where the system is in a steady state (equilibrium), or is undergoing a reversible process. In all other real cases, the total entropy always increases and the process is irreversible. The increase in entropy accounts for the irreversibility of natural processes, and the asymmetry between future and past.
First law of thermodynamics The first law of thermodynamics was developed empirically over about half a century. The first full statements of the law came in 1850 from Rudolf Clausius and from William Rankine; Rankine's statement is considered less distinct relative to Clausius'.[2] A main aspect of the struggle was to deal with the previously proposed caloric theory of heat.