Mr. Huang, I have two astronomical questions for you.

Let me answer the last two simple questions first.

Magnitude is an artificial parameter to measure the brightness of celestial bodies. Astronomers in ancient Greece divided the stars visible to the naked eye into 1-6 and so on. Among them, the brightest is the first category, and the barely visible is the sixth category, that is, the greater the magnitude, the darker the celestial body. Obviously, this requirement is not enough to meet the requirements of astronomical observation today. Therefore, it is considered that a brightness (equivalent to Vega's brightness) is specified as the base point, defined as 0, and the magnitude is not different by 100 times every five brightness. Compared with Vega, the magnitude of brighter objects is negative, for example, the brightness of the full moon is-12.7, and that of the sun is -26.7.

As for the source of these pictures, screenshots from Stellarium. This software is still very easy to use, powerful and easy to use. If you are interested, you may wish to download and play.

Well, to answer a question from the landlord, the landlord's discussion is based on one point. The angle of view of the moon at noon is smaller than that near the horizon, and he hopes to explain such a problem by atmospheric refraction. But in fact, the basis for this discussion does not exist. How can I put it? Because there is no obvious difference between the size of the moon at sunrise and that at mid-day. Is it inconsistent with the actual perception? Yes, my perception is the same. Unfortunately, this is the illusion of the naked eye.

The above is a famous picture of astrophotography. The moon rises in Seattle. Judging from this picture, I believe it is not difficult to compare the landlord. The size of the moon has not changed since it rose, right? Therefore, the perspective of the sun and the moon is a very interesting phenomenon in physiology, but unfortunately it is a false proposition in astronomy.

Since the basis of the discussion does not exist, the reason for the landlord's analysis can only be a secondary factor, and it is indeed the case. Although the surface of the moon will be slightly larger due to atmospheric refraction, the impact is less than 0.5%, which should be a level that can be directly ignored.

Even according to the discussion method of the landlord, there are serious mistakes in PS. The ground cannot be regarded as a plane, and the curvature must be considered.