Maxwell’s quasi-demon as a property of an ideal gas in the equilibrium state

The paper shows that for the case of an ideal gas in the equilibrium state there exists a method for splitting it into portions with different temperatures without energy transfer to or from the environment and without work being done. Compared with the thought experiment known as ‘Maxwell’s demon’, in which such splitting is based on sorting specific molecules according to their energy levels, the process described does not require the energy of a specific molecule to be determined. Here the splitting is guided by the average energy of a group of molecules. The paper establishes the fact that the average energy of molecules striking the wall over a period of time is higher than the average energy of all molecules constituting the gas; this fact is what substantiates our method. This explains how a process that may result in extracting a higher temperature portion of the gas in the equilibrium state is generally possible. The paper considers one of the implementations of this process. We also show that groups of molecules may be split off from the gas, the average energy of said groups being lower than the average energy of the gas molecules in total.