In one sentence, the second type of perpetual motion machine in science popularization radiation:

The radiation intensity of low-density gases is directly proportional to their density. Radiating gases with different densities can create a temperature difference: high density leads to low temperature. Low density, high temperature. The second law of thermodynamics is invalid.

Below are further text, simulation images, and literature links.

1. This setting includes radiation experience: when the gas density is low, the radiation intensity is proportional to the density, and the absorption coefficient is inversely proportional to the density (the smaller the absorption coefficient, the stronger the absorption capacity)----- Domain 1 gas density=1, Domain 2 gas density=2.

2. Radiation generates a temperature difference of 2.1 ℃, rendering the second law of thermodynamics invalid.

3. This transposition can be connected in series to generate stronger heating and cooling capabilities, with low cost, and can be industrialized and commercialized.

More detailed literature links.

Article Using COMSOL to Prove the Temperature Difference Caused by A...