<P> Entropy is a function of the state of a system which tells of limitations of the possibility of conversion of heat into work . </P> <P> For a simple compressible system, the work performed by the system may be written: </P> <Dl> <Dd> δ W = P d V, (\ displaystyle \ delta W = P \, \ mathrm (d) V,) </Dd> </Dl> <Dd> δ W = P d V, (\ displaystyle \ delta W = P \, \ mathrm (d) V,) </Dd>

Who discovered energy cannot be created or destroyed