Lately I have been watching many youtube videos investigating the question of whether or not moonlight has a cooling effect. The experiment is very simple. On a clear night with moonlight measure the temperature of two similar bodies, with one in the moonlight and the other shaded from the moonlight. The result is the temperature of the body exposed to the moonlight is consistently slightly cooler than the temperature of the body in the shade.
Generally speaking the people who accept the results at face value seem to be unaware of the phenomena of radiant cooling and the technical challenges of measuring temperature changes. The debunkers on the other hand point out that the effect is only apparent and can be readily explained in terms of radiant cooling:The moonshade makes it difficult for the body to radiate its heat to the cool night sky so it remains slightly warmer than the body in the moonlight which radiates heat more easily to the cool night sky. Case closed. However, after reading some of the exchanges and examining the design of experiments I have come to the conclusion that most of the "debunkers" have a different question in mind from the "believers". This is partly the fault of the "believers" since the question is usually more clearly expressed by the design of the experiment itself which requires that moonlight be compared to shaded moonlight . On the other hand the "debunkers" work with the metaphysical presupposition that being shaded from moonlight on a clear night is physically equivalent to a clear moonless night. If one holds that the two situations are not physically equivalent then it becomes necessary to design an experiment involving shaded moonlight where the effect of radiant cooling can be neutralized. One might say repeat the experiment with the same apparatus on a clear moonless night and it has been done by skeptics and no temperature difference is observed. However, that changes the question and the experiment since there is no moonlight that is being shaded. One commentator suggested that a mirror be used to redirect the moon light to a spot under the moonshade. I like this experimental modification because it respects the question the "believers" are asking. It does not substitute one question for another question and claim an answer to the second question is equivalent to answering the first question. Harry
