Sometime ago I tried to check if moonlight was able to cool objects on Earth. I made experiments using a thermometer DT -11 made by the Termprodukt company wich was able to measure temperature with accuracy to 0.05 degree of Celsius. Results were not convincing so I thought about focusing the moonlight. According to my hypothesis the average temperature of the Moon is -23°C (150.15 K) and because of it the most of energy the Moon radiates as infrared waves with wavelength 0.00193 cm, that is 1.93 x 10-5 m. Using my infrared camera I checked how different materials reflect this type of cold radiation. I froze a glass of water in the freezer. The picture below shows an experiment with a mirror. The glass with frozen water is shown in the left photo. The camera indicated the temperature + 3°C. The middle photo shows mirror temperature at a neutral point + 28°C and in the right one - temperature of reflection of the glass with ice + 25°C. The conclusion is that reflecting infrared light in the mirror did not help much in cooling.
Then I checked a glass pane and an aluminum sheet. The pictures below show results of the experiment. The glass sheet gave a result analogous to the mirror, also + 25 ° C. It means the infrared radiation does not penetrate through the glass and does not reach the reflecting surface of the sputtered aluminum in the mirror. The aluminum plate showed an amazing effect of the reflection of these waves, almost one hundred percent. The reflection temperature, just like the directly measured glass, was also 3°C.
I checked also a glass lens. I supposed the lens was not able to transmit infrared light. The photo on the left side shows result of the experiment. The lens reflected me. Temperature of my reflection in the lens was only one degree higher than environment.
This successful experiment with aluminium sheet suggests me to make experiments with an aluminium mirror for focusing moonlight on my thermometer.
This successful experiment with aluminium sheet suggests me to make experiments with an aluminium mirror for focusing moonlight on my thermometer.