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Ed Bo's comment

Ed Bo:


You need to understand the difference between gross radiative energy flows and the resulting net flow. All that the 2nd Law requires is that the net energy flow be from the hotter body to the colder body.

This has been well understood since the initial formulation of the 2nd Law. In Clausius’ own words:
“the principle [ that heat cannot by itself pass from a colder to a wamer body] implies that in the immediate interchange of heat between two bodies by conduction and radiation, the warmer body never receives more heat from the colder one than it imparts to it…we find that in one and the same process heat may be carried from a colder to a warmer body and another quantity of heat transferred from a warmer to a colder body without any other permanent change occurring. In this case we have not a simple transmission of heat from a colder to a warmer body, or an ascending transmission of heat, as it may be called, but two connected transmissions of opposite characters, one ascending and the other descending, which compensate each other.”
(Originally from Clausius’ Fourth Memoir, published in Philosophical Magazine, 1854)

So Clausius, who did more than anyone else to formulate the 2nd Law, has a specific term for the transmission of thermal energy from a colder to a warmer body: the “ascending transmission of heat”.
It is our attitude toward free thought and free expression that will determine our fate. There must be no limit on the range of temperate discussion, no limits on thought. No subject must be taboo. No censor must preside at our assemblies.

–William O. Douglas, U.S. Supreme Court Justice, 1952

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