Usually we say that the sunlight is hot and the moonlight is cold. As for the Sun, the matter is clear. It is enough to put a thermometer on sunlight at a hot, sunny day, and then cover it with something. The temperature difference will be significant.
But what about moonlight?
In internet we have many examples that moonlight decreases temperature.
I decided to check it. I tried to make a simple experiment. I have bought a termometer DT-11 of Termoprodukt company wich was able to measure temperature with accuracy to 0.05 degree of Celsius. During night of July 30 I have made the experiment. I placed the thermometer on the wooden platform and left it for temperature stabilization for around 20 minutes. I stood around 5 m from the thermometer because I was afraid that I could influence on the thermometer by warmth of my body. Next, every 5 minutes, I was approaching to the thermometer at a distance of no less than 2 meters, shone a flashlight and read the temperature. Every 10 minutes, I covered or uncovered the tip of the thermometer. To cover the tip of the thermometer, I have used a piece of tin housing of an electronic device. This sheet had small heat capacity, so it quickly cooled to ambient temperature after I had carried it in my hand. I have taken some photos of the experiment which are shown below.
But what about moonlight?
In internet we have many examples that moonlight decreases temperature.
I decided to check it. I tried to make a simple experiment. I have bought a termometer DT-11 of Termoprodukt company wich was able to measure temperature with accuracy to 0.05 degree of Celsius. During night of July 30 I have made the experiment. I placed the thermometer on the wooden platform and left it for temperature stabilization for around 20 minutes. I stood around 5 m from the thermometer because I was afraid that I could influence on the thermometer by warmth of my body. Next, every 5 minutes, I was approaching to the thermometer at a distance of no less than 2 meters, shone a flashlight and read the temperature. Every 10 minutes, I covered or uncovered the tip of the thermometer. To cover the tip of the thermometer, I have used a piece of tin housing of an electronic device. This sheet had small heat capacity, so it quickly cooled to ambient temperature after I had carried it in my hand. I have taken some photos of the experiment which are shown below.
The experiment lasted for over two hours and basically confirmed the thesis that after covering the tip of the thermometer the temperature increased in relation to that when the tip was exposed to the light of the Moon.
After coming back home I have mede an internet research and I have found an explanation of the moonlight effect on a website quora.com from which I am showing the picture below.
After coming back home I have mede an internet research and I have found an explanation of the moonlight effect on a website quora.com from which I am showing the picture below.
The website explains the phenomenon in the following way:
"The moonlight does not cause an object to get colder. It’s the object in the shade that gets warmer.When an object (or surface) is covered or shaded with a hand, roof, tree or cloud, it radiates less of its heat into the night air, and it will become slightly warmer than an object (or surface) that is exposed to the open night sky.
Actually, the Moon’s light (which is, of course, reflected sunlight) doesn’t have much to do with it at all. It’s all about Radiative cooling".
Everything seems logical. In fact I have covered the tip of the thermometer and the covered surface radiated less heat in atmosphere and the cover reduced air circulation around the tip.
As if the matter has been cleared up, but during this experiment it was a moment when the Moon moving across the sky was obscured by a post of balustrade and the moonlight ceased to fall on the thermometer. It turned out that the effect of temperature changes ceased to occur. The thermometer during the experiment has not changed its position relative to the post.
It seems, the matter needs further research. I have to invent some experiment before the next full Moon, which will settle the matter or only will bring us closer to the solution.
"The moonlight does not cause an object to get colder. It’s the object in the shade that gets warmer.When an object (or surface) is covered or shaded with a hand, roof, tree or cloud, it radiates less of its heat into the night air, and it will become slightly warmer than an object (or surface) that is exposed to the open night sky.
Actually, the Moon’s light (which is, of course, reflected sunlight) doesn’t have much to do with it at all. It’s all about Radiative cooling".
Everything seems logical. In fact I have covered the tip of the thermometer and the covered surface radiated less heat in atmosphere and the cover reduced air circulation around the tip.
As if the matter has been cleared up, but during this experiment it was a moment when the Moon moving across the sky was obscured by a post of balustrade and the moonlight ceased to fall on the thermometer. It turned out that the effect of temperature changes ceased to occur. The thermometer during the experiment has not changed its position relative to the post.
It seems, the matter needs further research. I have to invent some experiment before the next full Moon, which will settle the matter or only will bring us closer to the solution.