sunspots is about 4200°C, which is much higher than the temperature of splashing steel flowers and tungsten filament in light bulbs. However, the temperature of the sun's surface can even reach about 6000°C. Therefore, sunspots appear dark against the surrounding bright background. Its shape is very irregular and its size is very different. The diameter of small sunspots is about 1,000 kilometers, while the diameter of large sunspots can reach as much as 200,000 kilometers, which is more than ten times larger than the diameter of the earth.
The Sun and the Number of Sunspots
People can usually observe the sunspots with the naked eye when the sky is dark due to mist or wind and sand, or when the sun is rising or setting. Our ancestors used many methods to observe sunspots: some used a piece of black crystal to observe sunspots; some used a piece of translucent jade to look at the sun to look for sunspots; and there was also a "sunspot observation with oil in a basin", which was to fill a basin with oil, let the sun's rays shine into the basin, and see sunspots from the sun's shadow in the oil.
Observing sunspots
When a large group of sunspots appears on the sun, the compass on the earth will shake randomly and cannot indicate the direction correctly; homing pigeons , which are usually good at identifying directions, will also get lost; radio communications will also be seriously hindered, and even suddenly interrupted for a period of time. These anomalies will pose a great threat to the safe navigation of aircraft, ships and artificial satellites , as well as television faxes.
Sunspots can also cause climate changes on the earth. More than a hundred years ago, a Swiss astronomer discovered that when there were many sunspots, the earth's climate was relatively dry and agricultural harvests were good; while when there were few sunspots, the climate was humid and heavy rains caused disasters. The famous Chinese scientist Zhu Kezhen concluded through research: Any century with more records of sunspots in ancient books is the century with more particularly cold winters in our country. Others have counted changes in rainfall in some areas and found that this change repeats every 11 years, and speculated that this may be related to the increase or decrease in the number of sunspots.
Scientists have discovered that the number of sunspot activities has decreased, the interior is whitening, and the Little Ice Age may be coming.
Scientific workers studying earthquakes have found that when the number of sunspots increases, there are more earthquakes on the earth. The number of earthquakes generally follows a periodicity of about 11 years. Botanists have also discovered that the growth of trees also changes with the 11-year cycle of solar activity. Trees grow faster in years with more sunspots, and slower in years with fewer sunspots.
