This study has demonstrated that entropy is not a physical quantity, that is, the physical quantity called entropy does not exist. If the efficiency of heat engine is defined as η = W/W1, and the reversible cycle is considered to be the Stirling cycle, then, given ∮dQ/T = 0, we can prove ∮dW/T = 0 and ∮d/T = 0. If ∮dQ/T = 0, ∮dW/T = 0 and ∮dE/T = 0 are thought to define new system state variables, such definitions would be absurd. The fundamental error of entropy is that in any reversible process, the polytropic process function Q is not a single-valued function of T, P-V fig. should be P-V-T fig. in thermodynamics. and the key step of Σ[(ΔQ)/T)] to ∫dQ/T doesn’t hold. Similarly, ∮dQ/T = 0, ∮dW/T = 0 and ∮dE/T = 0 do not hold, either. Since the absolute entropy of Boltzmann is used to explain Clausius entropy and the unit (J/K) of the former is transformed from the latter, the non-existence of Clausius entropy simultaneously denies Boltzmann entropy.

## Discussion

Error above in both thermodynamics and calculus. Q and W are not functions, they're functionals depending on path! 'dQ' cannot be integrated to yield a function.