On July 22, 2009, there was a spectacular phenomenon in my country. The whole food belt has gone through many parts of our country.

] Basic knowledge of the daily food
The process of full -eclipse of the day can include the following five periods: the initial loss, food, food, light, and compound circle.
The full food instructions

The first loss of running from the west to east of the earth from west to east, so the day eclipse always starts on the west edge of the sun. The moment when the east edge of the moon just came into contact with the sun (the moment when the east edge of the moon and the west edge of the sun surface) was called the first loss. The initial loss is the moment when the day eclipse starts.
The food is not only starting from the beginning, which is the partial stage. The moon continues to run east, the part of the sun's round surface is gradually increased by the moon, and the strength and heat of the sun have decreased significantly. When the east edge of the moon is cut inside and the east edge of the sun, it is called food. At this time, the entire sun is covered, so food is the moment when the full -eclipse starts.

1. The regular eclipse occurs

Mi -day eclipse 5 times a year. If it appears 5 times, then it must be partial. There are at least 2 days a year on the earth. You can only see daily partial eclipse in the North and South Pole. Every day and a half of the day and a half, the day and a half. Each day eclipse starts from a certain point at sunrise, and then ends along the sun along the sun. From the beginning to the end point, about half a circle around the earth. The day eclipse must occur in Shuo, that is, on the day of the lunar calendar. At this time, the moon is between the earth and the sun, but because the sun orbit (zodiac) and the moon orbit (White Tao) become 5 ° 9 ′, so it is not every time the sun is eclipse. All must occur near the "yellow and white intersection point" (upgrade point or downgrade point).

2. Saro periodic

The days of eclipse (whole eclipse, circular and partial food) every 18 years or 6,585.32 days (Saro period), But the areas that can be observed are not the same, it is just the same time for eclipse, and it is not necessarily the same. Because the length of Saro is 6,585.32 days, it is not an integer, so if you appear again in the same place on the earth (not necessarily the same type of Japanese food), you need to wait for 3 Salo period. The next day after one -third of the Salo cycle after the day eclipse, the next day eclipse will be occurred. After the three Salo periods are about 54 years and 33 days, the solar eclipse will reappear in the same area. There are now 12 different big Sharow cycles, and one appears in 1937, 1955, 1973, 1991 and 2009 (the Yangtze River Basin, Wuhan, Hangzhou) for about 7.5 minutes.

3. The lunar eclipse is the moon shadow

The daily eclipse (moon shadow) moves about 1,100 miles per hour in the equator area, and the poles reach 5,000 miles per hour. The widest full -fed food belt is 167 miles. In areas where Japanese food passes, the range of partial eclipse can be seen up to 3,000 miles. The area where the full -eclipse belt is generally passed by is in the place where the ocean or deserted.

4. The principle of daily eating

The daily eclipse is the moon and the middle of the sun and the earth. Light, the dark shadow behind the moon happened to fall on the earth, at this time, a daytime food phenomenon occurred. People in the shadow of the earth began to see the sun gradually weakened, the sun was covered by round black shadows, and the sky turned dark. When all the sky was covered, the brightest stars and planets could be seen in the sky. The edge of the dark shadow of the moon gradually exposed the sun, and began to be glory and reunion.
[Edit this paragraph] The significance of the full -eclipse
The main reason for the reason why the full food is valued is that its astronomical observation value is huge. There are many major astronomy and physics discovery in the history of science that use the opportunity of daily full -eclipse, and only through this opportunity. The most famous example is a daily food in 1919, confirming the correctness of Einstein's general theory of relativity. Einstein published in 1915 that it seemed extremely unknown and unbelievable at the time. This theoretical prediction of light will turn in a huge gravitational field. The strongest gravitational field that humans can come into contact with is the sun, but the sun itself has a strong light. The weak starlight in the distance turns around the sun, and it cannot be seen at all. However, if the full -eclipse occurs, the sun is blocked, and the light can be measured. Opportunities appeared in 1919, but the whole food belt on the South Atlantic is far away and difficult. British astronomer Eddon set off with a strong observation team with enthusiasm and curiosity. The results of the observation are very consistent with the results of Einstein's advance calculation, and the theory of relativity has been recognized by the world since then.
In China, the full -time full -eclipse can only be seen in remote areas the previous two times. Once in 1980, only the Ruili area of ​​the China -Myanmar border was visible, and the other time was visible to the Mohe River at the Sino -Russian border and the northernmost tip of China after the Spring Festival in 1997. At that time, the author was interviewed by the newspaper's life, but at the same time, but also his dream when he was a teenager. The scale of the observation was large, and it was beyond imagination that astronomers and astronomical enthusiasts from all over the world squeezed a small northern Xinjiang town than the New Year. Because the number of people was greatly exceeded the reception capacity of the town, people only only people only have the ability to receive the town. Nengbu camping on train and car. At that time, it was still winter. The temperature during the day was about minus 25 degrees Celsius, and it could be below minus 40 degrees Celsius at night. Nonetheless, no regrets, no excitement, who are not excited, and see the whole day of the daily food as a rare and precious memory in life. Astronomical phenomenon such as day -to -day food, to say that it is really not directly related to people's daily life, eating, drinking and drinking. However, it represents an ultimate humanistic care, a kind of extreme love for nature, and a eternal curiosity and awe of the natural iron law that dominates everything. These cares, these loves, these curiosity and these awe.
The full food that is about to come on July 22, 2009 is becoming the focus of attention and media. And when paying attention to the best observation point and observation equipment, do you also know the most basic knowledge of the full day of eating? Please follow -
"God -given opportunities, don't lose 'heavenly'." On July 22, domestic astronomers sighed so much about the good "heaven" of the 500 -year observation of a full -eclipse. This is the most spectacular daily food in the century. Its width, long time, and regional population are rare. However, when paying attention to the best observation point and observation equipment, do you also know some of the most basic knowledge of full -eclipse?
Why do daily full -food always appear in different places?
The observations of full -food this day cover many large and medium cities and densely populated areas of the middle and lower reaches of the Yangtze River and South Asian countries in my country. On August 1, 2008, the last day was eaten, but only a few remote areas in Northwest my country in the appropriate observation belt in China. As we all know, the solar eclipse is because the moon blocks the light of the sun. At the time of the day eclipse, the area blocked by the sun to form a shadow "cone" between the moonland, and the part of the earth can be seen on the surface of the earth. Due to the restricted sunrise orbit, the surface can be cut to the largest cross section of the "cone", and the diameter is less than 270 kilometers. As the earth sweeps the narrow area, it can see a full -fed food. The relative positions and angles of the three, earth, and month every day when they occur every day, the "cone" of the moon shadow is also swept to different locations on the earth. Although full -food is not like comets and meteor shower for thousands of years, for a certain area, the "hundreds of years of encounter" by the media merchants at the moment is not exaggerated.
Why are the scope and duration of each observation?
The daily food on July 22 will last 6 minutes and 39 seconds (the longest 5 minutes and 55 seconds in our country). my country can see that the area of ​​the whole food is about 250 kilometers wide. The longest time, involving the most population. The rotation of the moon around the earth and the earth around the sun is oval, and the distance between the moon and the sun and the earth is always changing. The diameter of the sun is about 400 times the moon, so only the sun and the moon are "met" and the distance between the sun and the earth can completely block the light of the sun in direct sunlight when the sun and the moon distance are 400 times the distance and the day and the moon can form a full -daily food. When the full food is coming this time, the sun is located near the distant location, and the moon has just passed the nearly place. The shadow of the moon on the earth is also wide. And more than 80 % of the earth's surface are regions with rare ocean and human smoke. This time, it is rare to sweep the densely belt. The rotation speed of the moon around the earth is much higher than that of the earth around the Japanese, so the moving speed of the moon shadow on the surface of the earth is very fast. It is about 1800 kilometers/h in the equator area, and it is as high as 8,000 kilometers/h near the poles. The highest food can last about 7 minutes and 40 seconds, while in the middle and high latitudes are only a few minutes, and the daily food is not visible at all.
Why seem to be more common than full -eclipse?
If, according to Handan outstanding historical and cultural scholars, youth songwriters Shen Baofeng, for a long time, remembers the solar eclipse in the ancient tombs of the Han Dynasty: All ethnic groups have different explanations such as the day and other days, such as Tengu, and wolves every day. The way they solve. In ancient China, the folk was dealt with by a gongs and drums; because the day full -fed food was usually short (at most seven and a half hours), after people knocking on the beating, the sun might be reproduced immediately, so exempted from exempcting it from People's panic. China has a record of solar eclipse very early, and many stones are dug out of the tomb of the Han Dynasty. These stones portray the graphics of many sun, moon and stars, one of which is painted with "Sun and Moon", that is, the sun and the moon are stacked in the moon and the moon are stacked in the moon. Together, this was the day eating record at the time. The Chinese people's scientific interpretation of the solar eclipse is yin invading the sun. China has long known that it is regarded as "yin" for a long time, covering the sun that is regarded as "yang", which causes solar eclipse. In ancient times, there was a saying of "Yueying's Food", which means that the phenomenon of lunar eclipse occurs at the time of full moon. At the time of the sun, the ancient courts of China would also act; the Chinese believe that heaven represents nature, and the sun has the most lofty position in nature. The emperor is called the emperor, which means that he manages the people as heaven. Since heaven represents the emperor's father, it will warn the agent on the ground through the phenomenon of the sun, the emperor, clearly shows that he does something wrong, what should be careful, etc.; Come out, solar eclipse is a common situation. According to the ancient book avoidance town hall, the emperor did not go to the hall to make the early dynasty every time the Han Dynasty was eaten, and the small hall beside the partial hall was performed early, and everything was brief.
For the number of occurrences worldwide, there are more solar eclipse in one year than lunar eclipse. From the perspective of the earth, the trajectory of the sun and the moon's respective operation will have a "intersection" every six months. The time period of the daytail (eclipse during the day) may occur longer than the monthly period (rose season). There may be no monthly food once a year, but there must be two or five times a day, and the average daily full -eclipse worldwide will be once every 1.5 years. However, once the lunar eclipse occurs, half of the earth that is in the night can be seen. The monthly full eclipse is as long as tens of minutes or even a few hours. higher.
Why are the interval between a full -eclipse every two times in the same area in the same area?
It this time as the best observation area, the middle and lower reaches of the country in my country. The last day was 1575 in 434 years, and the next time it will be 2309 after 300 years. Ancient astronomical observer summarized that the time of the 223 -month change cycle at the same place and the time of the sun and the sun through the sun and moon rail intersection were basically the same, forming an 18 -year cycle. Since then, people have proposed other more complete cycles Essence Due to the observation reasons for the changes in the sun and the moon can only be calculated in an integer, the length of the two is not exactly equal. Coupled with the impact of the earth's rotation, two days apart from one cycle often do not occur at the same place, nor maybe it is all daily or daily partial eclipse. The time required to return to the same place is even more fixed. However, by strict
, a strict
can still accurately predict the time of a full -fed food in a certain underground.
What can the impact on the ground during the daily duration of the whole eclipse?
In different from the rainy cloud layer to cover the sun. When the full -day food occurs, as the moon is covered with solar radiation, some corresponding changes will occur at the ionization layer at the height of the atmosphere. This temporarily causes certain interference to the radio mid -wave and short -wave communication that needs to be reflected by the signal. Using ultra -short wave frequency radio broadcasting, mobile phones, wireless Internet access, etc., it is not affected. However, for the entire earth magnetic field, this impact is still small. In addition, on August 1, 2008, the temperature of the observation point of Xinjiang Iwu dropped by about 8 degrees Celsius, and many observers also felt that they suddenly became cold. This time, solar eclipse appears mainly in the summer and downstream of the Yangtze River in the summer, the temperature difference between the day and night in the summer of the city generally does not exceed 5 degrees Celsius. It also occurs in the morning during the heating period. The cooling caused by the solar eclipse will not be great.
Why can I look directly at the sun with the naked eye within a few minutes when they occur?
Except for the full food that the sun is completely covered by the moon for a few minutes, you can directly watch the full food of the sun with the naked eye. Do not use the naked eye to directly observe the sun with the naked eye. During a few minutes to reach the whole food, the brightest light ball layer of the sun was completely blocked. At this time, you can directly observe the sun with the naked eye or telescope, and appreciate the crowns and stars exposed in the sky. The camera or camera should also pick up the filter at this time, otherwise it will only take a ball of dark. However, the duration of the whole food is very short, and it will soon return to the partial eclipse. Even if only a small part of the light ball is exposed, it is enough to light up to hurt people's eyes and photography equipment. Therefore, when observing, you still need to prepare a solar eclipse to observe glasses, lens filter, etc., and grasp the time of the whole food.
Why do you say that you do n’t look at the full food of the sun is “lifelong regret”?
The people who watch the whole eclipse for their own views that they have witnessed the wonders of the sky and the red sun when the sky becomes dark. This kind of shock is difficult to replace by any photos and images. The rare scenes such as Bailey, Crown, and Nikko are even fascinated by astronomical lovers. Ordinary people who are not interested in astronomy will also add a little curiosity. Living in the middle and lower reaches of the Yangtze River and watching the full food at home at home is of course a life adventure, and for many people who have missed the full -food style in northern my country and Lingnan this time, if you really have a strong interest and travel out of this Conditions can also be added to the ranks of "global tracers" on the solar eclipse, and the average waiting one and a half years is not long. Future forecast of full -eclipse
1: China enters the high incidence of the daytime eclipse to reward 3 times in the next 4 years: China will usher in the first day of daily food for the first century. In the next 4 years, the Chinese public can also enjoy three rare days of eclipse, one of which is the daily eclipse and twice for the sun. Astronomical experts said that it is rare for a century to concentrate in 5 years. Zhao Zhizheng, director of the Tianjin Astronomical Society, said that since the 1980s, China has two full -daily foods that have been conducive to observation, once in 1980 in southwestern cities such as Kunming and Guiyang; Essence "This two years of Japanese full -food phenomenon, whether it is the range of the full food belt or the time of full food, is conducive to the observation of the Chinese public. As long as the heavenly public is beautiful, the public will be able to be full of eyes." Zhao Zhizheng said. In addition to this full -eclipse on August 1, 2008, on July 22, 2009, a more spectacular Japanese -eclipse will occur in China, and the whole food belt will sweep the Yangtze River Basin in central China. At that time, more than 40 cities such as Lhasa, Chengdu, and Shanghai in China can watch the full food this time. Compared with the full -eclipse on August 1st, the full -eclipse has a wider range and longer duration. It will reach 5 minutes to 6 minutes. This situation can be described as a hundred years of difficulty. In addition to these two daily full -eclipses, day -to -day eclipse will occur on January 15, 2010. The public in Yunnan, Sichuan, Hubei, Anhui and other places can see the style of the sun. On May 21, 2012, the Nikkei Edge Tianxiang was staged again. The public in Guangxi, Guangdong, Fujian, Hong Kong, and Macau can be appreciated. Astronomical experts said that there are so many days in the 5 -year episode that are rare for a century.
2: 2008 The forecast time and food of major cities nationwide: August 1, 2008, the first line of daily food in the first line of the first line from the Altay, Jiuquan, and Xi'an to Zhengzhou in China. About 8:20, the duration is about two minutes. This is the first time in China that has occurred in China in the 21st century.
[Edit this paragraph] Small eclipse
The process of full -eclipse every day can include the following five periods: first loss, food, food, light, compound circle.
The first loss

Because the moon runs from west to east to the earth, the solar eclipse always starts on the west edge of the sun. The moment when the east edge of the moon just came into contact with the sun (the moment when the east edge of the moon and the west edge of the sun surface) was called the first loss. The initial loss is the moment when the day eclipse starts.
The food
From the beginning of the loss, it is the partial stage. The moon continues to run east, the part of the sun's round surface is gradually increased by the moon, and the strength and heat of the sun have decreased significantly. When the east edge of the moon is cut inside and the east edge of the sun, it is called food. At this time, the entire sun is covered, so food is the moment when the full -eclipse starts.
The food is very
The after food, the sun wheels continue to move eastward. When the center of the month and the center of the day are the most recently, it is very good.

For the daily partial eclipse, the sun is the most time to be covered by the moon. The moon continues to move east. The moment when the west edge of the moon and the west edge of the sun surface is called the light of life. Before the light will occur, the phenomenon of diamond ring and Bailey will appear on the west edge of the sun, but it will soon disappear. Then a line of dazzling light was shot on the edge of the west of the sun. The phenomenon of color balls, sunrise, and crowns that could be seen when they were eaten in the sun were hidden in the sun, and the stars disappeared, and the sun re -shined on the earth.
compound circle
Pelasia continues to move away from the sun. The part of the sun's shielding gradually decreases. Essence At this time, the sun showed a disc shape, and the entire daily food process was announced.
[Edit this paragraph] Beryzhu, diamond ring
When the sun is about to be completely blocked by the moon, a light of diamonds will suddenly appear on the east edge of the sun. The eye -catching light, this is Diamond Ring, and at the same time, it is formed as a string of glowing highlights in an instant, like a string of glorious pearls hanging in the dark sky. This phenomenon is called pearl food. British astronomer Bailey first described this phenomenon, so it is also known as Baily Beads. This is because there are many rugged mountains on the surface of the moon. When the sun is shining to the edge of the moon, the phenomenon of Bailey is formed. Bailey's time is short, usually only one or two seconds, and then the sunlight is covered with all daylight.

It is used to indicate the degree of eclipse. For solar eclipse, the food score does not mean the area where the sun is covered by the sun, but it means the ratio of the covered part of the diameter of the sun surface to the diameter of the sun. With the diameter of the sun as 1, if the food is divided into 0.5, this means that the diameter of the sun is covered by half; if the food is divided into 1, that is, the entire round surface of the sun is covered, that is, the full daily food. Obviously, the larger the food score, the greater the degree of the sun surface. The daily partial eclipse is less than 1.0, and the full -eclipse is 1.0.
The diet belt
Because the moon's cone is thin and long, when it falls to the surface of the earth, the area occupies is small, and it will not exceed one thousandth of the total area of ​​the earth. The maximum diameter is only more than 2.60 kilometers. When the moon turns around the earth, the cone swept a long area from the west to the east on the ground. You can see the solar eclipse in the area wiped out in the moon shadow. So this belt is called "solar eclipse belt". If the full -eclipse occurs in the belt, it is called the whole food belt; if the daily eclipse occurs in the belt, it is called a circular belt. It can be seen that the range of partial eclipse is very broad, not like a belt, but a large area.
This belt is a narrow path with a width of only two or three kilometers and a length of thousands to 10,000 kilometers (sometimes the width of the whole food belt is only a few kilometers). The occurrence of full -food or sundial eclipse. On both sides of the full -food belt are a wide half -shadow -sweeping area, which can be seen in these areas. The closer to the whole eclipse, the greater the degree of partial eclipse; the farther away the straps, the smaller the degree of partial eclipse;
Since the moon is running from west to east, its shadow is also running along the same direction, so the time of seeing the sun in various places is different. The western region on the local area is already in the black shadow area. When people in this area have seen the solar eclipse, people in the eastern region cannot see the solar eclipse at the same time. Food. Therefore, people in the western region are always better than people in the eastern region.
The daily eclipse occurs every year, but because the full -food belt is a narrow shadow belt, it is estimated that on average, every 200-300 years, a certain area or city will have the opportunity to be swept through the whole food. For people in a city, I may not have seen a daily food once in my life.
In this century, the solar eclipse in China
August 01, August 01, 2008
This this day, Xinjiang Uygur Autonomous Region, Gansu Province, Ningxia Hui Autonomous Region, Shaanxi Province, Shanxi Province The whole food can be visible in some areas of Henan Province. In China, Jinchang City, Gansu Province is a better observation location.
July 22, 2009, full -eclipse
The best observation area in China in the Yangtze River Basin this time in the Yangtze River Basin for a long time. In addition, part of the varying degree of visibility in most areas of China.
In January 15, 2010
The China Rings area: northern Yunnan Province, southern Sichuan Province, northern Guizhou Province, northern Chongqing, northern Hubei Province, southeast of Shaanxi Province, most of Henan Province, most of Henan Province , Most of Shandong Province, northern Anhui Province, northern Jiangsu Province.
In May 20, 2012 Rings
The China Rings District: Southeast of Guangxi Autonomous Region, most of Guangdong Province, Hong Kong, Macau, Fujian Province, northeast of Taiwan Province
2020 July 21st, Rings Edge
The China Edge District: Central and South China, Sichuan Province, central and southern Sichuan Province, central and northern Guizhou Province, central Hunan Province, southern Jiangxi Province, southern Fujian Province, central and southern Taiwan Province.
The day of the day on June 01, 2030
The China Edge District: Northeast of Inner Mongolia Autonomous Region, central and northern Heilongjiang Province.
March 2034 Day full food
The full -food area in China: north of Tibet Autonomous Region, southwest of Qinghai Province.
September 02, 2035 full -food
The full -food region in China: central and southern parts of Xinjiang Autonomous Region, central and northern Gansu Province, central and western parts of Inner Mongolia Autonomous Region, northern Shanxi Province, central Hebei Province, most of Beijing, Tianjin City, Tianjin City, Tianjin City, Tianjin City, Tianjin In the north, southern Liaoning Province.
October 25, 2041 Edge
The northern part of the Inner Mongolia Autonomous Region, northern part of the Inner Mongolia Autonomous Region, northern Liaoning Province, and southwest of Jilin Province.
July 01, 2057 Rings
The area of ​​China Edge: The East Eastern area of ​​Xinjiang Autonomous Region, northern edge of Gansu Province.
April 30, 2060 full food
The full -food region in China: central Xinjiang Autonomous Region, junction of Qinghai Province and Gansu Province.
August 24, 2063 Full eclipse
The full -food area in China: East of the central part of Xinjiang Autonomous Region, central Inner Mongolia Autonomous Region, most of Jilin Province, and southeast of Heilongjiang Province.
The February 17, 2064 Rings
The China Edge District: Central Edge Zone in Tibet, southeast of Qinghai Province, northwest of Sichuan Province, central Gansu Province, most of Ningxia Autonomous Region, in the west of Inner Mongolia Autonomous Region South of the south, northern Hebei Province, northwest of Jilin Province, and southwest of Heilongjiang Province.
April 11, 2070 Full -food
The full -ends of the southern part of Taiwan Islands, the southernmost coastal area of ​​Taiwan Islands.
In January 27, 2074, Eating Edge
The China Edge District: Southeast of Guangxi Autonomous Region, central part of Guangdong Province, southeast of Jiangxi Province, and central Fujian Province.
In January 22, 2085, Eating Edge
The China Edge Area: South of Yunnan Province, northern Guangxi Autonomous Region, southern Hunan Province, central Jiangxi Province, northern Fujian Province
April 21, 2088 Day -day full food
The full -food area: central Xinjiang Autonomous Region, north of Qinghai Province and the junction of the southwestern part of Gansu Province
November 27, 2095 Rings Edge
, China Ring Woods: Hebei Province: Hebei Province Northeast, northeast of Beijing, Chifeng area of ​​Inner Mongolia, southern Liaoning Province
[Edit this paragraph] Century Day
July 22, 2009: Century Rente. With the black shadow of the moon landing on the Arabian Sea for the first time, and then through the central and northeast of India, southeast of Nepal, most regions of Bhutan, northern Bangladesh, the eastern and southern India, and central Tibet. The longest day of the century. Soon after, the shadow of the moon will pass through the central part of China, and then move to some areas of the East China Sea and the Ryukyu Islands in China. About 200 meters from east southeast of Sulsus Island is the best place to observe this day of eclipse. For some people, this may be the most perfect day eclipse in the 21st century. It lasts the longest duration between the sun that occurs between 1991 and 2132.

Observation day full -food precautions

The observation of the sun is very dangerous, because the sun radiates strong visible light, infrared and ultraviolet light. Ultraviolet light can not only sunburn, but also cause damage to the retina of the eyes quickly. As long as human eyes are directly watching the sun for a few seconds, it may cause permanent damage and even blind eyes. If you observe the sun without a telescope without appropriate light reduction equipment, the consequences are even more unimaginable. Nikkei and sunshine can not be watched without special safety measures. During the partial eclipse of the daily food, even if the surface of the sun is covered by the moon 99%, the light ball layer formed by the crescent moon can also cause damage to the eyes. Don't try to observe any daily partial or eclipse -eating sun with the naked eye.
The following introduces some scientific observation methods:
ink observation method (but this method is low, it is easy to hurt the eyes, it is not recommended)
Add ink and look at the sun through the reflection of the water.
Thole projection method
In two boards, dig a small hole on one of the boards, and let the sun go through this small hole to projection to another board.
The telescope projection method
This should not shake the hand, otherwise the shadow of the sun will run back and forth. And do not hold the telescope directly to see the sun. If you use the telescope to see the sun directly, you must use a filter.