An argument between two children.
One of the children in the "Two Children Debate Day" said that the morning is far from noon because the sun is cold and the noon is hot. The other said that the sun is big in the morning and small at noon, so the morning is far from noon, and the fact observation is true. So how to explain it? What the hell is going on?
One view is that there are clouds on the surface of the earth in the morning, and the sun looks big through the clouds. At noon, when the clouds cleared, the sun looked very small, but its size did not change.
There is also a view that the sun looks big because its height is different and its atmospheric refractive index is different. In the morning, the sun has a low altitude angle and a high refractive index.
Another view is that due to the illusion of the eyes, it seems that the sun in the morning is bigger than that at noon. The white figure we see is bigger than the black figure of the same size. This is called photodegradation in physics. When the sun rises, the surrounding sky is dark, so the sun appears bright, and at noon, the surrounding sky is bright. In contrast, the brightness difference between the sun and the background is not so big, which is why we look like the sun is bigger in the morning than at noon. In short, the sun is the same distance from us in the morning and at noon, so its size is the same.
Also, it is hotter at noon than in the morning, is it because the sun is closer to us at noon than in the morning? Not exactly. Why is this?
It is hotter at noon than in the morning because the sun shines directly on the ground at noon and obliquely on the ground in the morning. It can be seen that when the sun is in direct sunlight, the ground and the air receive more solar radiation heat at the same time and in the same area than when the sun is oblique in the morning, so they are heated the most. So it is hotter at noon than in the morning.
In fact, the hot and cold weather mainly depends on the temperature. The main factor affecting the temperature is determined by the radiation intensity of the sun, but solar photothermal is not the main reason for directly raising the temperature. Because the direct absorption of sunlight by air is only a small part of the total solar radiation, most of it is absorbed by the ground. After the ground absorbs the solar radiation heat, it is conducted upward to the air through radiation, convection and other heat transfer methods, which is the main reason for the temperature rise.
In short, it is not because the sun is far from our ground that it is hot at noon and cold in the morning every day.