Little is known about the Milky Way.

1. The Milky Way with little scientific knowledge

Galaxy of scientific knowledge 1. Knowledge of cosmic science 100 words or so (left handwritten newspaper (

There are about 200 billion stars in the whole galaxy. Astronomers divide these stars into two groups according to their age: the first group and the second group. The first group is some young stars, mostly distributed near the spiral arm of the silver disk, and the second group is some old stars, mostly concentrated in the silver core and halo. In the Milky Way, there are many single stars such as superstars, dwarfs and variable stars. There are also many stars and binary stars that appear in pairs. In addition to binary stars, there are many stars in the Milky Way, which are composed of more than two stars. For example, the North River of Gemini is Liuhe Star, and the South Gate of Centauri is Trinity Star. A cluster consisting of more than 10 stars is also an important member of the Milky Way.

2. Little scientific knowledge does not exceed five words.

Know little about astronomical science

▲. What is the universe?

A: The universe is the floorboard of everything in the world. It has no boundary, no end, no beginning and no end.

▲. How big is the Milky Way?

A: Many stars combine to form a huge galaxy. The galaxy where the solar system is located is called the Milky Way. The Milky Way is like a big discus, with a width of about 80,000 light years, a center thickness of about 1 0.2 million light years, and a total number of stars exceeding10,000.

▲. Why can't I see the stars during the day?

A: Because part of the sunlight is scattered by gas and dust in the atmosphere during the day, the sky is very bright and the light radiated by the sun is so strong that we can't see the stars.

▲. What celestial bodies are there in the solar system?

A: There are nine planets in the solar system. They are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. In addition, there are many asteroids, comets and meteors in the solar system, and there are 2958 officially numbered asteroids. The most famous comet is Halley's comet.

3. Little is known about the science of the universe

Stars in the Milky Way galaxy

There are about 200 billion stars in the whole galaxy. Astronomers divide these stars into two groups according to their age: the first group and the second group. Group I is some young stars, mostly distributed near the spiral arm of the silver disk, and Group II is some old stars, mostly concentrated in the silver core and halo.

In the Milky Way, there are many single stars, such as giant stars, dwarfs and variable stars, and there are also many binary stars. In addition to binary stars, you can also see many stars composed of more than two stars in the Milky Way. For example, the North River II of Gemini is the Liuhe Star, and the South Gate II of Centauri is the Trinity Star. A cluster consisting of more than 10 stars is also an important member of the Milky Way.

4. Knowledge about the Milky Way

Key points: A disk-shaped star system consisting of more than 200 billion stars, thousands of clusters and nebulae, with a diameter of about 100000 light years, a center thickness of about 6000 light years, and the sun located at the center of the Milky Way 26000 light years. The estimated age of the Milky Way is about 136 billion years. The overall structure is that the main part of the galactic material forms a thin disk called silver. Stars are very dense in the nuclear sphere, and there is a small dense area in its center, which is called the silver core. Outside the silver plate is a larger, nearly spherical distribution system, in which the density of substances is much lower than that inside the silver plate, which is called silver halo. There is also a silver corona outside the silver halo, and its material distribution is also roughly spherical.

The center of the Milky Way is the intersection of the rotating axis of the Milky Way and the galactic plane, and the core of the Milky Way-the silver core is in the direction of Sagittarius. As far as right ascension and declination are concerned, in 2000 it was right ascension 17 degrees 45.6 minutes and declination-29 00'. This "point" is not far northwest of Gamma Sagittarius, near the dividing line between Ophiuchus and Scorpio.

September 18 Beijing time According to foreign media reports, NASA recently announced that astronomers have discovered dozens of huge and very bright stars near the center of the Milky Way.

This discovery surprised experts: there is a huge black hole in the center of the Milky Way. The popular theory is that there can't be any celestial bodies near a black hole.

The discovery of these stars is also attributed to the Chandra X-ray space telescope in the United States. They are only 9.5 billion kilometers (less than 1 light-year) from the center of the Milky Way. It should be added that the distance from the Earth to the black hole in the center of the Milky Way is about 26,000 light years.

The volume of these stars discovered this time is about 30-50 times that of the sun, and the brightness is 100 times that of the latter. Astronomers believe that these stars may develop into Supergiant star and explode. Then, they will shrink and collapse under their own great gravity and eventually evolve into a group of small black holes.

Usually, the celestial body near the black hole is gradually swallowed up by the black hole and eventually disappears without a trace. Astronomers believe that giant black holes are located at the center of every galaxy.

As we all know, any matter, including stars, once trapped by the gravitational field of a black hole, will disappear without a trace. However, this recent major discovery by scientists shows that discoid gaseous matter at a certain distance around a black hole may also evolve into a star.

5. Little scientific knowledge

▲. What is the universe? A: The universe is the floorboard of everything in the world. It has no boundary, no end, no beginning and no end.

▲. How big is the Milky Way? A: Many stars combine to form a huge galaxy. The galaxy where the solar system is located is called the Milky Way. The Milky Way is like a big discus, with a width of about 80,000 light years, a center thickness of about 1 0.2 million light years, and a total number of stars exceeding10,000.

▲. Why can't I see the stars during the day? A: Because part of the sunlight is scattered by gas and dust in the atmosphere during the day, the sky is very bright and the light radiated by the sun is so strong that we can't see the stars. ▲. What celestial bodies are there in the solar system? A: There are nine planets in the solar system.

They are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. In addition, there are many asteroids, comets and meteors in the solar system, and there are 2958 officially numbered asteroids.

The most famous comet is Halley's comet. ▲. Why do stars have different colors? A: The color of a star depends on its temperature.

Different colors represent different surface temperatures: the surface temperature of blue stars is high and that of red stars is low. ▲. What is the brightest star? A: The brightest star in the sky is Sirius Canis with a magnitude of 1.46.

8.7 light years from the earth. ▲. How to find Polaris? A: It's easy to find Polaris in the sky: first find Ursa major, and then find the Big Dipper.

A straight line leads from the two Polaris at the edge of the spoon head, extends past and passes through the Polaris. The distance from Polaris to the spoon head is exactly five times the distance between two Polaris.

You can also find Polaris through Cassiopeia. ▲. How high is the blue sky? A: The "blue sky" is actually the earth's atmosphere.

The atmosphere is the air around the earth, which is divided into five layers according to the air density, with a total thickness of 2000-3000 kilometers. But most of the air is concentrated below 15 km from the ground, and the higher the air, the thinner it is.

How thick the atmosphere is, how high the blue sky should be. ▲. Why is the sky blue? A: When sunlight hits the earth's atmosphere, blue light is most easily separated from other colors, diffused into the air, and then reflected.

The light of other colors has strong penetrating ability, and shines on the earth through the atmosphere, so we can only see the blue light in the sun when we look at the sky. ▲. Why is the sky red at sunset? A: Because sunlight travels a long distance in the atmosphere at sunset.

Except for red light, all other colors of light can't travel that far, and they all disappear before they reach our eyes. Only red light runs farthest and can reach our eyes, so we see that the color of the sky turns red at sunset.

▲. Will the moon shine? The moon is not a star. It can't shine, but it can reflect sunlight. Although only 7% of the light it reflects can reach the earth, it is enough to light up the night on our earth.

▲. How many stars can we see? A: We can see 7,000 stars from the earth with the naked eye, but because the earth is round, no matter where we stand on the earth, we can only see half of the sky, and the stars near the horizon are not clear, so our naked eye can only see about 3,000 stars. ▲. How high is the temperature of the sun? A: The central temperature of the sun is as high as192,000,000℃ and the surface temperature is 6000℃.

But because the sun is far away from us, with1.500 million kilometers, we don't feel so hot. ▲. Why does the earth turn? A: Because the earth has gravity, it is precisely because of this gravity that the earth turns.

The rotation speed of the earth is per hour 1700 km, that is, 470 meters per second; The revolution speed is about 29.8 kilometers per second. ▲. Why is the sun white at noon? Answer: Because at noon, the sun can shine directly on the ground, unlike things on the ground (such as mountains, trees, buildings and turbid air) in the morning and evening, it is still the original white light, which makes people afraid to open their eyes.

▲. Why is it difficult to walk on the moon? A: Because the gravity on the moon is very small, it is easy to slip when walking, and only 20 steps can be taken in one minute. If you walk in a hurry, it's easy to fly. Once it flies, it is unstable for a long time. Therefore, it is very difficult to walk on the moon.

▲. Why doesn't the earth shine? A: Because the temperature of the earth is relatively low, the hottest place (the core) is two or three thousand degrees, unlike the temperature of the sun, which will cause thermonuclear reaction, so the earth will not shine. ▲. Why can't people feel that the earth is turning? A: Because the earth is very big and rotates smoothly, we are also following it. We take ourselves as a reference, so we can't feel the earth spinning.

▲. What is thunder? A: This is a natural phenomenon that negative electricity meets positive electricity. When it rains, some clouds in the sky are positively charged and some are negatively charged. When two clouds meet, they will discharge, emit bright and bright lightning, and at the same time release a lot of heat, which will make the surrounding air heated, expand and make a loud noise. This is thunder.

▲. What is a meteor shower? A: There are many small celestial bodies in the universe flying at their own orbits and speeds. Some blew themselves up and some collided with other celestial bodies.

But they kept flying. When their orbits meet the earth's orbit, they fall to the ground like raindrops. This phenomenon is called meteor shower.

▲. Where is the cloud going? A: Clouds are water vapor floating in the air. Air is also constantly flowing in the air.

The flow of air is the wind, which blows away the clouds. The faster the air moves, the faster the cloud moves.

▲. Why can an airplane fly into the sky? A: An airplane has two wings. Just like the wings of a bird, it also has a propeller. The wing can generate lift and lift the plane into the air; Propeller can produce the ability to push the plane forward.

Therefore, the plane can fly into the sky like a bird.

6. Collect 200 words about the Milky Way.

Who can understand the emperor? It is the emperor.

Therefore, only Li Shimin can tell who Cao Cao is. Emperor Taizong said to Cao Cao, "If you seek change in times of danger, you can expect the enemy to set up strange things. More wisdom, less talent. "

To put it bluntly, Cao Cao is a competent general, not a competent emperor. He fought like Sun Wu (Liu Beiyu) and defeated many stronger opponents. His incompetence is memorable, but even if he has the ability, he is not a competent founding monarch. Some people say that he is treacherous, but the real emperor will not be found even if he is treacherous. Liu bang is much better than him.

Of course, he is just a pawn in history. He hasn't finished unification yet. On the one hand, his personal ability is insufficient, on the other hand, it is also caused by the situation at that time. With the development of China's natural economy to the landlord stage of the gentry (from aristocrats to gentry to civilians is an inevitable trend), the possibility of separatist regime may increase. He just conforms to history, not creates it. Some people say that he wants to learn from his successful experience. Indeed, he is more successful than the average person. However, with Emperor Wu of Zhou,

His fighting skills are really outstanding. Some of the thirty-six plans, such as "Looking at Plums to Quench Thirst", are based on him. He fought Ma Chao in a decisive battle and crossed the Xihe Port with Song as a straight line, which really set a historical precedent (he was the first to successfully enter the customs from Xihe Port in history, and some people did it during the Warring States Period, but unfortunately he met Ying Zheng and). The battle of Guandu can rarely be won by fewer, besides, in fact.

However, he did not leave a capable, honest and loyal regime to future generations. Perhaps Sima Yi has some ability, but he can only cultivate a clean and honest regime (for the general founding regime, it can't be said to be absolutely clean and honest, but it is much better than the national subjugation regime). Too much pursuit is his greatest failure. Liu Bei got along with him through this weakness, and Sima Yi and others stayed in his regime. Therefore, his country was in danger of destruction as soon as it was established.

This is Cao Cao, an unsuccessful emperor and a fairly successful general.

7. Related knowledge of the Milky Way

How many stars are there in the Milky Way?

If you want to know how many stars there are in the Milky Way, you must first understand that the Milky Way looks like a big disk with a slightly protruding center. The diameter of the whole disk is about 654.38+ million light years, and the solar system is located about 26,000 light years away from the center of the Milky Way. The bulge is a densely populated area of stars, so we can know how many stars there are in the Milky Way, so we can see a vast expanse of whiteness. Seen from above, the Milky Way is like a huge whirlpool, consisting of four spiral arms. At the beginning of the 20th century, astronomers called the star system with the Milky Way as its apparent phenomenon the Milky Way. Scientists are still studying how many stars in the Milky Way.

The Milky Way is a lenticular star system, and the sun is not in the center. Shapley concluded that the Milky Way has a diameter of 80,000 parsec and the sun is 20,000 parsec from the center of the Milky Way. These values are too large, because shapley did not consider interstellar extinction when calculating the distance. In the 1920s, after the discovery of the rotation of the Milky Way, shapley's model of the Milky Way was recognized. The Milky Way is a huge rod-shaped spiral galaxy (a kind of spiral galaxy), Sb type, * * * type, with four spiral arms. Contains 100 billion or 200 billion stars. The overall rotation of the Milky Way is not good. The rotation speed at the sun is about 220 km/s, and the sun revolves around the center of the Milky Way for about 250 million years. The absolute visual magnitude of the Milky Way is -20.5. The total mass of the Milky Way is about 1 trillion times that of our sun, and about 10 times that of all the stars in the Milky Way. This is a strong evidence that dark matter exists in our galaxy, far beyond the bright astrolabe. Regarding the age of the Milky Way, the popular view is that the Milky Way was born shortly after the Big Bang. Calculated by this method, the age of our galaxy is about 65.438+0.45 billion years old, and the upper and lower errors are more than 2 billion years each. The scientific community believes that the "Big Bang" of the birth of the universe occurred about 654.38+03.7 billion years ago. On the other hand, the diameter of the Milky Way is about 80,000 light years. Knowing this region clearly can answer the question of how many stars there are in the Milky Way.

Regarding how many stars there are in the Milky Way, scientists estimate that there are about 200 billion stars in the whole Milky Way. Astronomers divide these stars into two groups according to their age: the first group and the second group. Group I is some young stars, mostly distributed near the spiral arm of the silver disk, and Group II is some old stars, mostly concentrated in the silver core and halo. In the Milky Way, there are many single stars, such as giant stars, dwarfs and variable stars, and there are also many binary stars. In addition to binary stars, you can also see many stars composed of more than two stars in the Milky Way. For example, the North River II of Gemini is the Liuhe Star, and the South Gate II of Centauri is the Trinity Star. A cluster consisting of more than 10 stars is also an important member of the Milky Way. More content is in the video of Spark Video: How many stars are there in the Milky Way?

8. Knowledge of the Milky Way

What is the Milky Way? If we scan the sky roughly with the naked eye, it seems that we have seen all the stars in the sky.

There is no place where the stars look particularly dense, and there is no place where the stars look particularly sparse. From this, we can draw a conclusion that for us, the stars are evenly distributed in all directions. If the whole star can form a * * * body with a certain shape, then the shape must be spherical.

Obviously, all large celestial bodies are similar to spheres. Why can't the whole galaxy be regarded as a sphere? Of course, there are only 6,000 stars that we can see with the naked eye, and most of them are quite close to us. What will we find if we use a telescope? The answer is that we see more stars, which seem to be evenly distributed in the sky-except the Milky Way.

To the naked eye, the Milky Way is a weak band of light (now if we live in a city, it is difficult to see the Milky Way because the sky is artificially illuminated). It looks pale milky white.

In fact, there is a fairy story about it: a long time ago, when Zeus' wife Hera was breastfeeding her baby, her milk flowed into the sky, forming this faint light band. The Greeks called it galaxias kyklos (silver ring), and the Romans called it via lactea (Galaxy), from which we got its English name.

But what is the real Milky Way? If we don't consider fairy tales, then we can first think of the ancient Greek philosopher democritus. Around 440 BC, he proposed that the Milky Way actually consists of a large number of stars, which cannot be distinguished separately. But they gather together to give off a soft light.

Although this view has not attracted people's attention, it is completely correct. 1609, Galileo aimed the first telescope at the sky and found that the Milky Way contains a large number of stars. This theory was confirmed.

What do you mean by "a huge number"? When people look at the night sky, their first impression is that there are countless stars, too many to count. But I mentioned several times that the total number of stars visible to the naked eye is only about 6000, and the number of stars seen through telescopes is much more.

Does this mean that they are countless? Stars in the direction of the Milky Way are very dense, while those in other directions are relatively rare, which means that we must abandon the whole concept of stars forming spherical structures. In that case, there should be as many stars in all directions as there are in the direction of the Milky Way. Under the background of weak light, the closer stars twinkle (not as spectacular as it is now), and the whole sky will be illuminated.

Then, we must assume that stars exist in large aspherical clusters and extend farther in the direction of the Milky Way than in other directions. In this case, the Milky Way galaxy shows that all the stars gather in the shape of a lens or hamburger.

This lens-shaped cluster is called the Milky Way (Greek explanation comes from the Milky Way), and the name of the Milky Way has been preserved because of the dark light band around the sky we see. The first person to suggest that stars exist in shadow galaxies is thomas wright, a shadow astronomer.

He put forward this suggestion in 1750, but his idea seemed so confusing and incomprehensible that few people paid attention to him at first. Of course, even if the Milky Way is lens-shaped, it can always extend in the long diameter direction.

Although only a few stars can be seen outside the Milky Way, there are countless stars inside the Milky Way. To illustrate this problem, William Herschel calculated the number of stars.

It is naturally impossible to count all the stars in a certain period of time. Herschel chose 683 small areas, evenly distributed in the sky, and then counted the stars seen through the telescope in each area.

In this way, he got the number of stars that we now call "imaginary voting" in the sky. This is the first example of the application of statistics to astronomy.

Herschel believes that the number of stars in each region is related to its proximity to the Milky Way. In all directions, the number of stars increases steadily as they approach the Milky Way.

From the number of stars he counted, we can estimate the number of stars in the Milky Way and the possible size of the Milky Way. 1785, he announced the results, and proposed that the long diameter of the Milky Way is about 800 times the distance from the sun to Sirius, and the short diameter is 150 times this distance.

Half a century later, the actual distance of Sirius was calculated, and Herschel concluded that the long diameter of the Milky Way was 8000 light years and the short diameter was 1500 light years. At the same time, he calculated that there are 8 billion stars in the Milky Way.

Although this is a huge number, it is not uncountable. In the past two centuries, astronomers have explored the Milky Way with much better instruments and techniques than Herschel can use. Now they know that the Milky Way is much bigger than Herschel expected.

It extends at least 654.38 million+light-years in the long diameter direction and may have 200 billion stars. However, it can be said that we have confirmed that galaxies and stars are not numerous but computable, thanks to Herschel.

The Milky Way is a huge disk-shaped system composed of stars and galactic matter, and the sun is a member of this system. The light from many stars in the Milky Way formed the Milky Way, which became an irregular luminous band around the night sky.

This starlight belt is generally located on the plane of the silver plate. The Milky Way is one of the billions of galaxies that make up the universe.

It has tens of billions of stars and a considerable amount of interstellar gas and dust. The Milky Way is a typical spiral galaxy in the galaxy type.

Its core is surrounded by a huge central nuclear ball, surrounded by spiral arms. These curved arms make the shape of the Milky Way look like a giant wheel.

The spiral arms sink evenly into the silver plate. The silver disk is the main part of the Milky Way, with a diameter of about 70,000 light years.

The silver core is shielded by interstellar dust particles and absorbs visible light and ultraviolet light in silver nuclear radiation. However, scientists can record and study the radiation emitted by silver nuclei in radio, infrared, X-ray and γ-ray bands.

In particular, the intense emission of infrared radiation and X-rays indicates the existence of ionized gas clouds moving at high speed. It is generally believed that this gas cloud is orbiting a massive celestial body, which is likely to be a black hole with a mass of about 4 million suns.

Scientists have confirmed.