The origin of the stars? The so-called stars in the sky are basically stars, but the stars in the solar system are planets.
Let's talk about the creation of the universe:
The origin of the universe
The universe is the general name of the vast space and all kinds of celestial bodies and dispersed substances existing in it. The universe is a material world, which is in constant movement and development.
Huai Nan Zi. Original note: "The four directions are called Yu, and from ancient times to the present, Zhou is called heaven and earth." In other words, the universe is the floorboard of everything in the world.
For thousands of years, scientists have been exploring when and how the universe was formed. Until today, scientists are convinced that the universe was formed by a big bang about 654.38+0.5 billion years ago.
Before the explosion, all the matter and energy in the universe gathered together and condensed into a very small volume with extremely high temperature and density, and then a big explosion occurred.
The big bang dispersed the matter, expanded the space and lowered the temperature accordingly. Later, all the galaxies, stars, planets and even life in the universe were gradually formed in this process of continuous expansion and cooling.
However, the theory that the Big Bang produced the universe cannot accurately explain what existed before "stored matter and energy gathered at one point".
The "Big Bang Theory" was established by Gamov in 1946. It is the most influential theory in the modern cosmic system, also known as the Big Bang Cosmology. Compared with other models of the universe, it can explain more observational facts. Its main point is that our universe once had an evolutionary history from hot to cold. During this period, the cosmic system is not static, but constantly expanding, which makes the density of matter evolve from dense to sparse. This process from hot to cold, from dense to thin, is like a huge explosion.
According to BIGBANG's cosmology, the whole process of BIGBANG was in the early universe, and the temperature was extremely high, above 1000 billion degrees. The density of matter is also quite large, and the whole universe system is in equilibrium. There are only some elementary particles in the universe, such as neutrons, protons, electrons, photons and neutrinos. But because the whole system is expanding, the temperature drops rapidly. When the temperature drops to about1000 billion degrees, neutrons begin to lose the condition of free existence, and they either decay or combine with protons to form heavy hydrogen, helium and other elements. It was from this period that chemical elements began to form. When the temperature further drops to 654.38 0 million degrees, the early process of forming chemical elements ends.
The substances in the universe are mainly protons, electrons, photons and some lighter nuclei. When the temperature drops to several thousand degrees, the radiation decreases, and the universe is mainly gaseous. Gas gradually condenses into gas clouds, and then further forms various star systems, becoming the universe we see today.
What is a star in the world?
The birth of stars
Extremely thin matter, mainly composed of gas and dust, is ubiquitous in interstellar space. Their temperature is about 10 ~ 100 K, and their density is about 10-24 ~ 10-23 g/cm3, which is equivalent to 1 ~ 10 hydrogen atoms in/kloc-. The distribution of interstellar matter in space is not uniform, and it usually appears in blocks, forming a diffuse nebula. Three-quarters of the matter in the nebula is hydrogen, which is electrically neutral or ionized, and the rest is about? It is helium and some elements heavier than helium. There are also molecules of gaseous compounds in some areas of the nebula, such as hydrogen molecules and carbon monoxide molecules. If a nebula contains enough matter, it is dynamically unstable. Under the influence of external disturbance, the nebula will shrink inward and split into smaller clumps. After many times of division and contraction, the center of the bundle will gradually form a dense core. When the temperature in the nuclear region rises to the point where the hydrogen fusion reaction can take place, a new star is born. '
dwarf star
The development stage of a star with internal hydrogen fusion as its main energy source is the main sequence stage of the star. Stars in the main sequence star stage are called main sequence stars. The main sequence stage is the youth and middle age of the star, and the time that the star stays in this stage accounts for more than 90% of the whole life. This is a relatively stable stage, the two forces of outward expansion and inward contraction are roughly balanced, and the stars basically do not contract or expand. The time that a star stays in the main sequence phase changes with the change of mass. The greater the mass, the greater the luminosity, the faster the energy consumption and the shorter the time to stay in the main sequence stage. For example, stars with mass equal to 15 times, 5 times, 1 times and 0.2 times the mass of the sun are in the main sequence stage 1 0 million years, 70 million years,10 billion years and11 trillion years respectively.
Now the sun is also the main sequence star. The age of the sun is now over 4.6 billion years. Its main sequence stage has passed about half, and it will take another 5 billion years to turn to another evolutionary stage. Compared with other stars, the mass, temperature and luminosity of the sun are roughly in the middle, and it is a quite typical main sequence star. Many properties of the main sequence star can be obtained by studying the sun, and some results of star research can also be used to understand some properties of the sun.
Red giant star and red giant star
When the hydrogen in the central region of the star is exhausted to form a nuclear sphere composed of helium, the thermonuclear reaction of hydrogen fusion cannot continue in the central region. At this time, the gravity pressure is not balanced by the radiation pressure, and the central region of the star will be compressed and the temperature will rise sharply. After the temperature of the central helium core ball rises, the layer of hydrogen-helium mixed gas near it is heated to the temperature of hydrogen fusion, and the thermonuclear reaction begins again. As a result, the helium sphere gradually enlarged, and the hydrogen combustion layer also expanded outward, so that the outer layer of the star was heated and expanded and turned into a red giant or a red Supergiant star. During the metamorphosis period, the hydrogen combustion layer may generate more energy than that during the main sequence star period, but the surface temperature of the star will not increase but will decrease. The reason is that the cohesive attraction of the outer layer decreases after expansion, and even if the temperature decreases, its expansion pressure can still compete with or exceed gravity. At this time, the radius and surface area of the star increase more than the productivity, so the total luminosity may increase, but the surface temperature will decrease. When a big star whose mass is four times higher than that of the sun re-initiates hydrogen fusion outside the helium nucleus, the energy released outside the nucleus does not increase obviously, but the radius increases many times, so the surface temperature drops from tens of thousands of Kelvin to three or four thousand Kelvin, becoming a red Supergiant star. Small and medium-sized stars whose mass is less than 4 times that of the sun enter the red giant stage, and the surface temperature drops, but the luminosity increases sharply. This is because their outward expansion consumes less energy and generates more energy.
It is estimated that the sun will stay in the red giant stage for about 654.38 billion years, and the luminosity will rise to dozens of times today. By then, the ground temperature will rise to two or three times as high as it is now, and the highest temperature in the northern temperate zone in summer will be close to 100℃.
The death of massive stars
After a series of nuclear reactions, massive stars form an onion-like structure with heavy elements inside and light elements outside, and its core is mainly composed of iron cores. After that, the nuclear reaction could not provide energy for the stars, and the iron core began to collapse inward, while the peripheral stars were blasted and ejected outward. The duration of an explosion may suddenly increase to tens of billions of times that of the sun, or even reach the total brightness of the entire galaxy. This kind of explosion is called supernova explosion. After the supernova explosion, the outer layer of the star disintegrated into an outward expanding nebula, leaving a high-density celestial body in the center.
The famous Taurus Crab Nebula is the remnant of a supernova explosion in A.D. 1054. Although the time of supernova explosion is less than 1 s, the instantaneous temperature is as high as trillion K, which has a greater impact. Supernova explosion has a key influence on the chemical composition of interstellar matter, which is the raw material for building the next generation of stars.
When a supernova explodes, it will explode and collapse at the same time, which makes the matter at the core more dense. Theoretical analysis proves that electron simplification is not enough to resist the abnormal high pressure of big collapse and big explosion. Under such great pressure, electrons are squeezed and combined with protons to form neutron degeneracy, and the density reaches 1 100 million tons/cubic centimeter. A celestial body made of this substance is called a neutron star. A neutron star with the same mass as the sun has a radius of only about 10 km.
Theoretically, neutron stars also have an upper mass limit, which cannot exceed about three times the mass of the sun. If the residual material in the core exceeds about 3 times the mass of the sun after the supernova explosion, the degenerate neutron state cannot resist the pressure and can only continue to collapse. Finally, when the mass shrinks to a very small size, the gravity near it is large enough to keep the fastest moving photons from getting rid of the bondage. Because the speed of light is the speed limit of any known substance, even a celestial body that can't get rid of photons can bind any substance, so this celestial body can't send any information to the outside world. Any medium used by the outside world to detect it, including photons, will be sucked in by it as soon as it approaches it. It doesn't shine, devours everything including radiation, just like a dark bottomless pit, so this special celestial body is called a black hole. Black holes have many peculiar properties, and the study of black holes is of great significance in contemporary astronomy and physics.
Scientists have found that Jupiter and Saturn scatter more energy than they absorb, which means that Jupiter and Saturn can also emit light, but they emit far infrared rays instead of visible light.
Most of the above answers are from others ~ In fact, there are many science and education films about the universe and the formation of stars ~ Mr. Hawking's A Brief History of Time is the first one about the universe, but I don't know what stage your age is. This book is more suitable for senior high school or above ~ But I haven't finished reading it ~ I hope you are better than me-
What is the history of the stars? If you ask the stars, you will ask the universe. An international research group recently estimated that the universe may be "older" than originally thought, and it may be "older" by 654.38+05.8 billion years. 19 16, Einstein put forward a general theory of relativity that questioned the invariance of the universe. Although it failed, it marked the beginning of modern cosmology. 1924, Friedman judged according to general relativity that the universe is either expanding or contracting, but it will never be at rest, but this theory has not been confirmed by experiments. By 1929, Hubble carefully studied the spectra of many galaxies and found that most of them had blue shifts (that is, the distance from us became smaller) except for a few. Moreover, since we are not in a special position in the universe, Hubble's law applies to any galaxy, and its conclusion is that the universe is expanding. Hubble's discovery provides an observational basis for Friedman's model of the universe and clears the way for further study of the origin and evolution of the universe. Now that the universe is expanding, there should be a starting point. According to Hubble's law, the distance of galaxies divided by the speed can be calculated as10-200 billion years ago. At the same time, according to the thermonuclear reaction theory, people estimate the age of the oldest star in the Milky Way as100-1500 million years. Using two different theories, the calculated age of celestial bodies is consistent with the age of the universe, which gives strong support to the cosmic explosion. It was the microwave background radiation discovered by penzias and Wilson that provided convincing evidence for the Big Bang theory. It is estimated that the temperature one second before the explosion is 65.438+000 billion K, so an important relic after the explosion is microwave background radiation. After the explosion, due to the thermal balance, the radiation intensity follows the blackbody spectrum distribution, and with the expansion of the universe and the decline of radiation temperature, the blackbody spectrum type and overall uniformity are always maintained. Because the peak wavelength of this radiation is about one millimeter, it is in the microwave band. 1964, penzias and Wilson discovered radiation, which undoubtedly proved the blackbody and universality of microwave background radiation and became the most convincing evidence of the Big Bang. It is generally believed that the early universe was very hot, and only the "cosmic soup" composed of protons, neutrons, photons, electrons and other basic particles in the universe was in equilibrium. About three minutes after the explosion, neutrons and protons synthesized light elements such as hydrogen, helium, deuterium, tritium and lithium. Before the explosion, gravity, force, weak force and electromagnetic force were inseparable, and after the explosion, 10-44 seconds was super-unified. 10-36 seconds later, the super-uniform phase transition occurs again, and it is strongly differentiated. 10- 10 seconds later, weak force and magnetic force differentiated, completing the differentiation history of the four functions. Then, after billions of years, neutral atoms condensed into protogalaxies, which continued to burn as primitive stars and finally split to form the Qian Qian. With the burning of stars, the evolution of the universe has formed three levels: galaxies, stars and solar system. The universe is constantly changing. For people, our understanding of it is quite superficial. The universe is extremely mysterious. After expansion, the universe will collapse, shrink again, and finally return to one point and end. The exploration of the universe is endless. I believe that people will know more about the universe in the future.
The origin of the star, the origin of the star, the variant of IRE "star": each.
Pinyin: "Athena Chu"
Radical: Japanese radical strokes: 4 total strokes: 9
Kangxi dictionary strokes (star: 9; ) structure: up and down
Wu Bi 86: JTGF Wu Bi 98: JTGF Cang Xie: AHQM
Four-corner number: 60105 unicode: u+661f specification Chinese character number: 1488
Star: Last name
Kangxi dictionary explanation
Chen Ji went to the Ministry of Life; Kangxi strokes: 9; Page number: Page 492, No.2 1
[ancient prose]
Origin of Sanxingdui Name (1) Introduction of Sanxingdui Site
Sanxingdui Ancient Site is located in the south bank of Yahe River in the northwest of Guanghan City, Sichuan Province, with a distribution area of 12 square kilometers. It has a history of 5000 to 3000 years. It is the largest, longest-lasting and richest cultural site in southwest China so far. The most complete east, west, south wall and Moon Bay inner wall are all available. Sanxingdui site is regarded as one of the greatest archaeological discoveries of the 20th century, which shows that the Yangtze River basin, like the Yellow River basin, belongs to the matrix of Chinese civilization and is known as the "source of Yangtze River civilization".
Among them, the unearthed cultural relics are precious human cultural heritage, and among the cultural relics in China, they are one of the most historical, scientific, cultural, artistic and ornamental cultural relics. Among these ancient Shu treasures, there are bronze giants with a height of 2.62 meters, bronze masks with a width of 1.38 meters and bronze sacred trees with a height of 3.95 meters, all of which are unique. The gold ware represented by the golden staff, the jade and stone tools represented by the decorative edge Zhang are also rare treasures that have never been seen before.
(2) The origin of Sanxingdui's name.
The name Sanxingdui was named by archaeologists according to three yellow mounds at the excavation site, which means mounds shaped like Samsung.
The origin of Mars? To people on earth, Mars looks like a "red planet". Because it is red, it shines like fire, and Mars is called the God of War. Perhaps because of its bright red color, it is sometimes called the "red planet". Before the Greeks, the ancient Romans once worshipped Martians, a god who rarely talked about agriculture. The aggressive Greeks regard Mars as a symbol of war, and the name of March also comes from Mars.
Mars myth, god of war, the symbol of Mars, was called "Mars" in ancient times. This is because Mars is red, glowing like fire, and its brightness often changes. Moreover, in air movement, sometimes from west to east, sometimes from east to west, the situation is complicated and chaotic, so China called it "welcoming" in ancient times, which means "welcoming fire and leaving confusion." Meaning.
I hope it helps you ~
The origin of the comet
The solar system is like an atomic system, in which comets, like electrons in atoms, are celestial bodies with negative charges and repulsive force fields, and both come from the edge of Oort cloud outside the solar system-the Kuiper Belt. Oort cloud sound is a fragment of the sun's early companion body. Comets from this nebula are all irregular, but different from spherical planets. Because the field of a comet is a repulsive force field, not a gravitational field, and the repulsive force (-mg) of its field strength acting on the object is not a centripetal force but an outward force, it is impossible for it to have satellites orbiting it. The nucleus of a comet is called a comet nucleus because it is a fragment of a star's corpse. Because its substance is very heavy, it is easy to fission and radiation, and there is always a substance that collapses in fission and radiation. Both coma and tail come from this place, which is visible and invisible because of the distance and sunlight. When approaching the sun, the matter coming out of generate in the nucleus always falls behind it, so the tail is always behind it and facing the direction of the sun. At a very close distance, the material from the front of the nucleus is also irradiated by sunlight, which is a rare fan-shaped tail on the front.
Starbucks' name "Starbucks" comes from an extremely cool and charming first mate in the novel Moby Dick by American writer Melville. His hobby is drinking coffee.
From the brand name of Starbucks, we can clearly define the positioning of its target market: not ordinary people, but a group of urban white-collar workers who pay attention to enjoyment and leisure, advocate knowledge and respect people-oriented, and are rich in petty bourgeoisie.
Founded in 197 1, Starbucks Coffee Company is the world's leading specialty coffee retailer, roaster and Starbucks brand. Its retail products include more than 30 kinds of world-class coffee beans, hand-made espresso and various coffee hot and cold drinks, fresh and delicious cakes, as well as various coffee machines, coffee cups and other commodities.
How many stars are there on the American flag? The origin of each star is 18 18. In 2008, the US Congress passed a bill, and the red, white and wide stripes on the national flag were fixed at 13. The number of five-pointed stars should be the same as the number of States in the United States. Every time a state is added, a star is added to the national flag, which is generally implemented on July 4 of the second year after NSW joins. So far, the national flag has increased to 50 stars, representing 50 States in the United States.