Some problems about watching the solar eclipse in 29

Most of the total solar eclipse belt that will occur on July 22nd, 29 is in the Pacific Ocean, and almost all the ones located on land are in China, passing through densely populated provinces and cities such as Sichuan, Chongqing, Hubei, Anhui, Jiangsu, Zhejiang and Shanghai, while some other provinces in China can only see partial solar eclipses in different situations. The total solar eclipse can be seen in Hangzhou, Huzhou, Jiaxing, Ningbo, Zhoushan and Shaoxing in the China-Zhejiang eclipse belt. Other cities can also see different degrees of partial solar eclipse, even in the southernmost part of Zhejiang, you can see a partial solar eclipse with an eclipse of about 91.4%. Zhoushan is the easternmost city in this total solar eclipse zone. The city's observable time can be as long as 2 hours and 4 minutes; Secondly, there is no shelter on the sea surface, while most other cities are located in basins, and there are many mountain shelters, which is not conducive to observation; Third, when the total solar eclipse occurs, Zhoushan has the largest solar altitude angle and the best observation effect. Through the research of international astronomical organizations, Daishan and Shengsi counties in Zhoushan City are very close to the center line of the total solar eclipse belt, which can be said to have unique geographical advantages. Will the next visible total solar eclipse occur in China in 215, and it will be limited to the northern region. For people in Zhejiang province, the next time they watch the total solar eclipse at home, it will be June 9, 239, and they will never see it again in this life, so this total solar eclipse is an excellent opportunity for people in Zhejiang, so don't miss it.

among all the geodesics in Zhoushan city, Shengsiji Lake has the highest latitude, the closest to the center line of the total solar eclipse zone, and the longest duration of the total solar eclipse, making it the best observation site. Note: generally do not observe in crosswalks, roads, banks without railings and roofs, otherwise it is likely to cause unnecessary trouble and even life-threatening!

How to correctly observe the total solar eclipse

Note: Don't directly observe

Medical experts point out that "solar retinitis", which burns the macula of the retina due to its ultraviolet rays and infrared rays for a long time, is almost incurable. Macula is the most sensitive part of the retina, which makes the light converge and makes the image clear. Once burned, the macula will never recover. You may not feel it when you are burned, but you will react after a few hours. For this reason, when watching the total solar eclipse, we should first pay attention to one thing: never look directly at the sun with the naked eye or any optical equipment (such as telescopes)! This is not only a suggestion, but also a very serious warning. How to avoid some accidents? The following methods are introduced to you.

(1) A quick and simple observation method

In fact, the suggested method is only to use two blank sheets of paper. One white watch is used as a screen, and the other cardboard is poked with a pinhole. Lift the pinhole cardboard as far away from the screen cardboard as possible. The farther the distance between the two boards is, the larger the image will be.

Of course, there is a simpler way. Just use your own hands to help you lift your hands, and your fingers are perpendicular and overlapping, so your hands form a net with many small holes, which can be used as simple imaging holes.

(2) autonomous observation glasses

protective glasses need a special pair of glasses. There are glasses with this kind of special sun protection glasses on the market, and the price is about 5 yuan. You can also make your own observation glasses:

1. Smoke a thick layer of carbon on ordinary sunglasses, the darker the better;

2. Paint thick black ink on the glass, dry it and use it as a lens.

special suggestion-observing partial eclipse: when observing or taking pictures, you must pay attention to wearing sun observation glasses and adding appropriate filters.

Observe Bailey Beads and Prominences: The key to shooting Bailey Beads and Prominences is to grasp the right time, because they are fleeting and can last for a few seconds at most. Therefore, we must start to pay close attention to the frosted glass on the viewfinder one or two minutes before the food is eaten and before the light is born, and make a decisive exposure as soon as we see Bailey Beads and Prominences. We must never hesitate for a moment, and be careful not to forget to remove the filter.

remember: if you don't use scientific viewing methods, it will do harm to people's eyes. In the past, this kind of injury happened frequently, and some of them even caused the viewers to be blind forever. Please learn the knowledge about how to watch the total solar eclipse seriously.

[ Edit this paragraph] Introduction to solar eclipse

Solar eclipse is when the moon turns around the earth between the sun and the earth. If the sun, the moon and the earth are in a straight line, the moon blocks the sunlight that hits the earth, and the shadow behind the moon just falls on the earth. At this time, solar eclipse occurs. People in the shadow of the moon on the earth began to see that the sun gradually weakened, and the sun was covered by a round shadow. When the sky turned dark and was completely covered, the brightest stars and planets could be seen in the sky. After a few minutes, the sun gradually emerged from the edge of the shadow of the moon and began to glow and last contact. Because the moon is smaller than the earth, only people in the shadow of the moon can see the solar eclipse. Total solar eclipse occurs when the moon blocks all the sun, partial solar eclipse occurs when it blocks part of the sun, and annular solar eclipse occurs when it blocks the central part of the sun. The duration of the total solar eclipse does not exceed 7 minutes and 31 seconds. The longest duration of an annular eclipse is 12 minutes and 24 seconds. In order to delay the observation of the total solar eclipse, a French astronomer chased the shadow of the moon by supersonic plane, which extended the observation time to 74 minutes. China has the oldest solar eclipse record in the world, and there has been an exact solar eclipse record for more than 1 years BC.

[ Edit this paragraph] Scientific explanation

Eclipses are typical examples of light propagating in a straight line in celestial bodies. When the moon moves between the sun and the earth, it doesn't happen every time. There are two conditions to meet when an eclipse happens. First, solar eclipses always occur on the first day of the lunar calendar. Not all solar eclipses will occur on the first day, because the orbit of the moon (the ecliptic) and the orbit of the sun (the ecliptic) are not on the same plane. There is an included angle of 5 9' between the ecliptic plane and the ecliptic plane. If both the sun and the moon move near the intersection of the ecliptic and the ecliptic on the first day, and the sun is at a certain angle from the intersection (eclipse limit), an eclipse will occur, which is the second condition to be met.

Because the orbits of the moon and the earth are not perfect circles, and the distance between the sun and the moon and the earth is near and far, the shadow formed by the sun's shading by the moon can be divided into umbra, pseudoumbra (formed when the moon is far away from the earth) and penumbra on the earth. The observer can see the total solar eclipse within the umbra; Annular eclipse can be seen in the range of pseudoumbra; Only partial solar eclipse can be seen in the penumbra.

There are many high mountains on the surface of the moon, and the edge of the moon is irregular. When the valley on the edge of the moon fails to completely cover the sun at the moment when the eclipse or light comes, the uncovered part forms a luminous area, like a crystal diamond; The reddish aperture around constitutes the "ring" of the diamond ring, which looks like a diamond ring inlaid with bright gems on the whole. Sometimes a lot of particularly bright light or light spots are formed, as if a string of pearls were embedded around the sun, which is called Belle Pearl (Belle is a French astronomer).

whether it is a partial solar eclipse, a total solar eclipse or an annular solar eclipse, the time is very short. The area where solar eclipse can be seen on the earth is also very limited, because the moon is relatively small and its umbra is relatively small and short, so the umbra does not sweep across the earth for a long time. Because the average length of the umbra of the moon (373,293 kilometers) is less than the average distance between the moon and the earth (384,4 kilometers), the number of annular eclipses occurs more than the total solar eclipse on the whole earth.

[ Edit this paragraph] Eclipse eclipse

When a total solar eclipse occurs, it can be divided into five eclipse images according to the position relationship between the round surface of the moon and the round surface of the sun:

1. The moon moves faster than the apparent motion of the sun. The moon caught up with the sun during the eclipse. When the eastern edge of the moon just "touches" the western edge of the sun, it is called the first loss, which is the first "circumscribed" and the beginning of the solar eclipse.

2. eat well. About an hour after the initial loss, the moment when the eastern edge of the moon and the eastern edge of the sun "cut in" is called eclipse, which is the beginning of the total solar eclipse, when the moon covers the whole sun;

3. eat a lot. It is the moment when the sun is the deepest eclipse, and the center of the moon moves to the nearest center of the sun;

4. generate light. The moment when the western edge of the moon and the western edge of the sun "cut in" is called light, which is the end of the total solar eclipse; It usually takes only two or three minutes from eating to lighting, and the longest time is no more than seven and a half minutes;

5. last contact. About an hour after the birth of light, when the western edge of the moon "touches" the eastern edge of the sun, it is called last contact. From then on, the moon completely "leaves" the sun, and the eclipse ends.

[ Edit this paragraph] The picture shows

Why did a part of the sun disappear? This is the part of the sun that was hiding behind the moon. This is the first partial solar eclipse in 25 and the last total solar eclipse that can be observed before March 26. During the eclipse, the sun, the moon and the earth are in a straight line. This total solar eclipse first appeared in the South Pacific, and the area where partial eclipse can be observed spanned South America and North America to the south. The scene of the above image was taken by a hand-held digital camera last Friday. After a rainy day in Holly Mountain, North Carolina, USA, some of the eaten sun temporarily penetrated through the dark clouds. After taking a series of images, this best photo of the solar eclipse is combined with another photo that is not so good but has a plane.

[ edit this paragraph] frequency of occurrence

The following are the frequency of solar eclipses worldwide in the 2th century (191-1999):

partial solar eclipse 78

annular solar eclipse 73

total solar eclipse 71

mixed solar eclipse 6

total 228

[ edit this paragraph] Watch the solar eclipse.

.12mm thick

Visual observation: 5. dimming 1 times

Photography: 3.8

During this period, the sun will not emit any special rays. The observation of solar eclipse is often misinterpreted. The sun will not predict the occurrence of solar eclipse on the earth and will not emit other rays, so it is harmless to stay outdoors during the eclipse. But should we stare or glance at the partial eclipse? Although the sunlight during the eclipse is much weaker than usual, if you look straight, it will still hurt your eyes and may damage your cornea. People stare or squint at the sun out of curiosity. Of course, the partial solar eclipse is still very dazzling. If you look at the sun for a long time, your cornea will be damaged before you know it. During the eclipse, the eyes were damaged not because of the abnormality of the sun, but because people were curious and didn't pay attention to protective measures. Don't look directly at the sun with your eyes, whether an eclipse occurs or not; Don't use so-called "sunglasses"; Don't use "sunglasses", not even a few stacked ones; Don't look at the image of the sun in the mirror or on the water; Look at the sun with no.14 welding mirror; Watch it with a specially coated Myra mirror, which can be obtained from the famous planetarium or science museum; Construct a hole projector.

[ Edit this paragraph] Mistakes in Watching the Solar Eclipse

Note that it is absolutely a big mistake to directly wear sunglasses to observe the total solar eclipse. This is because the lenses have the function of focusing. Sunglasses are too close to the eyes, and the sun will burn the eyeballs, which may even cause blindness. It is not advisable to observe directly with the naked eye. The correct way is to take off the sunglasses, one arm away from the eyes, and observe the lenses from the side. In addition, it is also a good method to observe by pinhole imaging or basin reflection.

You can also put a piece of glass coated with ink in front of your eyes, or smoke the glass on fireworks. The thickness of the ink layer should be even, so that your eyes can see the sun bronzed through it, and you can see it clearly without stabbing your eyes. Never look directly at the sun with the naked eye or telescope.

[ Edit this paragraph] The story of the solar eclipse

For ancient people, the solar eclipse was very terrible. If you can understand the influence of the sun on grain cultivation and daily life, you will be concerned about why the sun in the sky suddenly disappeared. In ancient China, it was thought that the solar eclipse was caused by a dragon swallowing the sun, and other civilizations also thought it was an ominous sign. There were many "solutions": playing drums, shooting arrows at the sky, taking things or offering sacrifices to people, etc. It is said that there was a fatal solar eclipse report error. This means that two astronomers in China in the 2nd century BC did not report the solar eclipse for some reasons. At that time, the emperor of China thought he was the son of heaven, and attached great importance to astronomical phenomena. He thought it was a hint from heaven, so he invited a group of astronomers to observe astronomical phenomena regularly. Comets and meteors could not be predicted at that time, but solar eclipses could be predicted. The two astronomers didn't tell the emperor about the solar eclipse, and the emperor was furious and beheaded them. Astronomers then were much more dangerous than they are now.