Stávek, J. 2023. What is Hidden in the Planck Distribution Function and the Wien´s Peaks? III. Fission of Solar Photons into Thermons (“Dark Heat”). European Journal of Applied Physics. 5, 2 (Mar. 2023), 17–25. DOI:https://doi.org/10.24018/ejphysics.2023.5.2.242.