How do ordinary people observe sunspots safely with simple tools?

When the large sunspot group has a large area, the sun has just risen from the eastern horizon, or is about to sink into the western horizon, and the sunshine is mild but not dazzling, people with good eyesight can directly see the sunspot group with the naked eye.

Huainanzi recorded the earliest sunspot in the world. "There are black spots in Japan and China." The sunspot record in Hanshu Wuxing Zhi is more detailed: "In the first year of Taiping, on March 2, the sunrise was yellow, and there was black gas as big as money, living in central Japan." From the first year of Heping in Han Dynasty to Chongzhen in Ming Dynasty, about 100 sunspot activities with definite dates were recorded. In these records, the shape, size, position and even changes of sunspots are recorded in detail.

At sunrise and sunset, when the sun comes out, a thin layer of clouds or fog blocks it. Otherwise, the eyes will be stimulated to see the sun. You can record sunspots after seeing them. It is said that the ancients still had a way to see sunspots, so they made a big washbasin filled with water to keep the water calm. When the sun reflects on the water, it reflects the image of the sun and sees sunspots on it.

The surface temperature of the sun is about 5700℃. The sunspot is low, between 3000-4500℃, so the sunspot is obviously darker than the surrounding area, just slightly lower. They are in sharp contrast with the surrounding environment, even with the human eye. Compared with other parts of the sun, any sunspot looks dark. If you don't have a safe solar filter, don't look directly at the sun with binoculars or other things.

Looking at the fire on the earth, especially the fire, you can also see the light and darkness, rushing up like a torrent, creating a whirlpool. Sunspots are actually huge hot gas swirls on the surface of the sun, and the temperature is about 3000-4500℃. Because the sun is very big and the gravity is very strong, this vortex looks like a small point on the sun, moving slowly, but it is actually very big and moving quickly. Generally, the depth is 500 kilometers, the small diameter is 1000 kilometers, and the large one is 200,000 kilometers, which can hold a dozen or twenty earths. Generally speaking, the formation and disappearance of sunspots take several days to several weeks. At the peak of sunspot activity, the old sunspot disappears and the new sunspot reappears, so it suddenly disappears and reappears.

The formation of sunspots is closely related to the solar magnetic field. However, astronomers have not found the exact answer to how it came into being. However, scientists speculate that it is very likely that the strong magnetic field has changed the material structure of a certain area, making the light and heat inside the sun unable to reach the surface effectively, forming such a "low temperature zone".

Sunspots rarely move alone and usually appear in groups. The sunspot activity cycle is about 1 1 year, which will affect the earth's magnetic field. When a large number of sunspots appear on the sun, a magnetic storm will occur, which will cause the compass to shake at will and indicate the wrong direction. Pigeons who are good at discerning directions will get lost. Radio communication will also be seriously hindered, and even suddenly interrupted for a period of time. These anomalies will pose a serious threat to the safe navigation of aircraft, ships, satellites and television faxes.