Essay! ! The universe and human beings

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BIGBANG released a lot of matter and huge energy, and I don't know how many years have passed. The universe has not been finalized, there are no galaxies and planets, and there is no life. There is darkness everywhere, and hydrogen atoms are still in the void; The dense air mass scattered everywhere gradually becomes larger in indecision, and hydrogen gathers into an air mass much larger than that of modern stars; Finally, the torch of nuclear reaction is lit in these atmospheric masses. In this way, the first generation of stars came into being, thus illuminating the dark space. Nuclear fission produces heavy elements and dust left by hydrogen combustion, which are the raw materials needed by future planets and life forms.

Superstars soon exhausted their nuclear fuel reserves. Affected by the big bang that happened later, these stars sent most of the matter back to the thin gas that originally formed them. Then, in the dense clouds between stars, a new polymer composed of various elements was formed, thus producing a new generation of stars. Although the smaller aggregates nearby can also become larger, they are too small to stimulate nuclear fission, so they are developing towards planets. One of them is a small star made of rocks, which is the early earth.

In the process of continuous melting and condensation, the early earth released a lot of methane, ammonia, water and hydrogen, which were captured by the earth and formed the primitive atmosphere and ocean. Under the bath of the sun, the earth becomes warmer and warmer, and storms, lightning and thunder are produced. Volcano erupts and magma surges. All these processes make the molecules in the primitive atmosphere split, the fragments of molecules recombine, and gradually generate increasingly complex material forms, which are dissolved in the primitive ocean. After a while, the sea water turned into a warm and thin liquid. On the surface of the earth, the combination of molecules and complex chemical reactions have taken place. One day, it happens that one molecule can take other molecules as raw materials and copy the same molecule as itself. With the passage of time, molecules have emerged that can replicate themselves more accurately and finely. Natural selection favors those molecules with the strongest replication ability. Which molecules replicate well will increase. Due to the consumption of molecular replication and the complex condensation of self-replicating organic molecules, the original seawater gradually becomes thinner. Unconsciously, life slowly appeared.

The following data prove that there is dark matter outside the universe, about 28 billion light years away.

British Media Reveals the Mysteries of the Six Universes

Is there a tenth planet in the solar system, and is there life on Mars-

Science can explain many strange things, however, there are still some mysteries of the universe that cannot be explained by current science. The British magazine "New Scientist" published today in Beijing time reveals six mysteries of the universe that even the cleverest brains in science can't solve.

In the solar system

There is a tenth planet?

If humans can fly to the edge of the solar system far from Pluto by spaceship, they will see that when the spaceship flies over the asteroid-strewn Kuiper Belt, it will suddenly encounter a vast void.

Astronomers call this boundary point at the edge of the solar system "Kuiper Belt Cliff". The only explanation is the existence of the tenth planet in the solar system. However, no one has been able to find this planet so far.

"mysterious power"

Pull the detector off the tracks?

Pioneer 10 was launched on 1972, and pioneer 1 1 was launched one year later. Now both detectors have disappeared into the vast space forever. Scientists have found that some "mysterious force" is pushing or pulling the two detectors, causing them to accelerate their flight.

Archer

There's an alien signal

This is a 37-second wireless signal from outer space. This signal comes from Sagittarius and uses a radiation pulse of about 1420 MHz. The nearest star in Sagittarius is also 220 light years away. If this wireless signal really comes from there, there must be a miracle-or an alien civilization sent a signal with a super transmitter.

On Mars

Is there life?

1On July 20th, 976, the Viking Mars probe landed on Mars. The detection results of Viking are exciting. It shoveled some soil mixed with carbon 14 from the surface of Mars. The detection results show that some Martian organisms absorb this soil nutrient and digest it, releasing methane gas containing carbon 14.

However, another device for detecting organic molecules is also installed on the Viking Mars probe, which shows that there is no life signal on Mars. Is there life on Mars? This debate lasted for nearly 30 years.

Existence in the Milky Way.

Dark matter?

Scientists have concluded that 90% of the universe is made up of dark matter. However, at present, no scientist can answer what dark matter is.

What is the end of the universe?

Can maintain thermal balance?

Scientists have found that microwave radiation in the universe keeps the same temperature everywhere, although the two ends of the universe are separated by 28 billion light years.

Interviewee: Four Seasons Records-Manager Level 4 5- 15 19:03

astronomy

[solar system]

(Note: In the resolution No.5 adopted by the 26th International Astronomical Union held in Prague on August 24th, 2006, Pluto was listed as a dwarf planet, named asteroid 134340, and was eliminated from the nine planets in the solar system. So now there are only eight planets in the solar system. All the references to "nine planets" in this article have been changed to "eight planets". )

The solar system consists of the sun, nine planets, 66 satellites and countless asteroids, comets and meteorites. The order of planets from the sun to the outside is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Mercury, Venus, Earth and Mars near the sun are called terrestrial planets. Spacecraft have all detected and landed on Mars and Venus, and achieved important results. Their common characteristics are high density (>: 3.0 g/cm3), small volume, slow rotation, few satellites, mainly silicate inside and firm shell. Jupiter, Saturn, Uranus, Neptune and Pluto, which are far away from the sun, are called woody planets. The spacecraft also detected them, but they didn't land. They all have a thick atmosphere, and their surface features are difficult to understand. Generally speaking, they all have solid cores similar to terrestrial planets. There are more than 100000 asteroids (that is, irregular small stars composed of rocks) between Mars and Jupiter. It is speculated that they may be formed by fragments of a planet between Mars and Jupiter, or some rock fragments failed to accumulate into a unified planet. Meteorites exist between planets and are made of stone or iron.

Star, distance (AU), radius (Earth), mass (Earth), orbital inclination (degrees), orbital eccentricity, inclination and density (g/cm3).

Sun, 0,109,332,800,-,-,-,1.4 10.

Water Star, 0.39, 0.38, 0.05, 7, 0.2056, 0. 1, 5.43.

Venus, 0.72, 0.95, 0.89, 3.394, 0.0068, 177.4, 5.25.

Earth, 1.0, 1.00, 1.00, 0.000, 0.0 167, 23.45, 5.52.

Mars, 1.5, 0.53, 0. 1 1 .850, 0.0934, 25. 19, 3.95.

Mu Xing, 5.2,11.0,318, 1.308, 0.0483,3.12, 1.33.

Earth satellites, 9.5, 9.5, 95, 2.488, 0.0560, 26.73, 0.69.

Uranus, 19.2, 4.0, 17, 0.774, 0.04 1, 97.86, 1.29.

Neptune, 30. 1, 3.9, 17, 1.774, 0.0097, 29.56, 1.64.

Pluto, 39.5,0.18,0.002,17.15,0.2482,119.6,2.03.

Among the nine planets, Mercury, Venus, Earth and Mars are collectively called Earth-like planets. Their similarity is that they are mainly composed of stone and iron, with smaller radius and mass, but higher density. Jupiter, Saturn, Uranus and Neptune are called woody planets. Their similarity is that they are mainly composed of hydrogen, helium, ice, methane, ammonia and so on. Stone and iron account for only a small proportion. Their mass and radius are much larger than that of the earth, but their density is lower. Pluto is a special planet. The distance between the planet and the sun is regular, that is, the distance between the planet and the sun (represented by a) is a=0.4+0.3*2n-2 (astronomical unit), where n represents the nth planet from near to far (see the above table for details). The rotation period of the Earth, Mars, Jupiter, Saturn, Uranus and Neptune is about 12 hour to one day. Except Mercury and Venus, all other planets have satellites orbiting them, forming a satellite system.

In the solar system, more than 1600 comets have been found, about half of which revolve around the sun in the same direction and the other half in the opposite direction. Comets will have strange shape changes when they orbit the sun. There are also a large number of meteoroids, large and small, in the solar system, some of which are in groups and are the products of the disintegration of comets. Large meteoroids fall to the ground and become meteorites. The solar system is a small part of the Milky Way. It's just one of hundreds of billions of stars with galactic coefficient. It is about 8,500 parsec from the center of the Milky Way, which is less than 30,000 light years. The sun takes the whole solar system around the center of the Milky Way. Visible, the solar system is not in the center of the universe, nor in the center of the Milky Way. The sun was formed by the collapse of a small piece of interstellar cloud 5 billion years ago, and its life span is about 65.438+0 billion years.

[space flight]

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. 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 founded by Gamov in 1946.

Big bang theory

Big Bang Cosmology is the most influential theory in modern cosmology, also known as 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 6.5438+0 million degrees, the early process of forming chemical elements ends (see the theory of element synthesis). 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. The Big Bang model can uniformly explain the following observations:

(1) According to the Big Bang theory, all stars were born after the temperature dropped, so the age of any celestial body should be shorter than the period when the temperature dropped to today, that is, less than 20 billion years. The measurement of the ages of various celestial bodies proves this.

(2) It is observed that the celestial bodies outside the river have a systematic red shift of spectral lines, and the red shift is roughly proportional to the distance. If it is explained by Doppler effect, then the red shift is a reflection of the expansion of the universe.

(3) Helium is abundant in various celestial bodies, most of which are 30%. The mechanism of stellar nuclear reaction is not enough to explain why there is so much helium. According to the big bang theory, the early temperature was very high and the efficiency of producing helium was also very high, which can explain this fact.

(4) According to the expansion speed and helium abundance of the universe, we can calculate the temperature of the universe in each historical period. Gamov, one of the founders of the Big Bang theory, predicted that today's universe is already very cold, and the absolute temperature is only a few degrees. 1965 detected microwave background radiation with thermal radiation spectrum in microwave band, and the temperature was about 3K.

...........................................................................................................................................

Humans have long wanted to swim in space. 1903, mankind opened up the first moon park on earth. You can board a winged car in the shape of a cigar for 50 cents, then the car body shakes violently, and finally board a moon model.

In the same year, the Wright brothers crashed in the air for 59 seconds, and a self-taught Russian named Konstantin Ziolkowski published an article entitled "Exploring Space with Reaction Instruments". In his article, he calculated that the missile must fly at a speed of10.8 million miles per hour to overcome the gravity of the earth. He also suggested building a liquid-driven multistage rocket.

In the 1950s, there was an accepted basic view that which country successfully established the permanent space station first would control the whole earth sooner or later. Wernher wernher von braun described intercontinental missiles, submarine missiles, space mirrors and possible trips to the moon to Americans. He once envisaged the establishment of a space station with frequent manned and capable of launching nuclear missiles. He said: "If we consider that the space station flies over all inhabited areas on the earth, then people can realize that this nuclear war technology will give satellite manufacturers an absolute advantage in the war.

196 1 year, Gagarin became the first man to go into space. Russians use him to show that it is not angels or God flying around in the sky. John F. Kennedy's campaign slogan in the United States is "New Frontier". He explained: "We are once again living in an era full of discovery. Space is our inestimable new frontier. " For Kennedy, the Soviet Union's first entry into space was "the most painful failure that the United States has experienced for many years". The only way out is attack and defense. 1958, the United States established the National Aeronautics and Space Administration, and launched the first satellite "Explorer" in the same year. 1962, john glenn became the first American to enter Earth orbit.

Many scientists are skeptical about the dangerous manned space flight, and they prefer to explore the solar system by plane.

At that time, Americans achieved a breakthrough: three astronauts flew around the moon in the Apollo spacecraft. In this context, the first docking of two manned spacecraft scheduled for June 1969+ 10 is of special significance.

In 1980s, the third generation space station "Peace" of the Soviet Union reached the peak of its space activities, which made Americans jealous. The "Peace", known as the "Artificial Tiangong", was launched on1February 20th, 986. It is the only manned space orbital station that can run in near-earth space for a long time. The cabins corresponding to quantum 1, quantum 2, crystal, spectrum and nature form a huge space orbit complex with a weight of 140 tons and a working volume of 400 cubic meters. There are 106 Russian and foreign astronauts who have been inspected in this "small space factory", with as many as 22,000 scientific research projects and 600 key projects.

The most attractive experiment carried out on the "Peace" is to prolong people's stay in space. Prolonging people's stay in space is the most crucial step for people to fly out of the cradle earth and March into Mars and other celestial bodies. To solve this problem, we need to overcome weightlessness, cosmic radiation and psychological obstacles caused by people in space. Russian astronauts have made great progress in this respect, among which astronaut poliakov created a record of 438 days of continuous flight of "Peace", which cannot but be regarded as an important achievement in the history of space flight in the 20th century. A large number of life science experiments such as cultivating quail, salamander and planting wheat were carried out on the orbital station.

If the Mir space station is regarded as the third generation space station, the International Space Station belongs to the fourth generation space station. The International Space Station (ISS) project costs more than 60 billion US dollars, and it is the largest manned spaceflight project of mankind to date. From the initial conception to the final implementation, it is not only the product of the competition between the United States and the Soviet Union, but also the result of the current cooperation between the United States and Russia, which reflects a historical process from the side.

The implementation of the International Space Station program is divided into three stages. The first phase from 1994 has been completed. During this period, the United States and Russia mainly carried out a series of joint manned space activities. The American space shuttle docked with the Russian "Peace" orbital station eight times and flew together, which exercised the ability of American astronauts to live and work in the space station. The second stage started from June1998+065438+1October: Russia put the main cabin of the space station, the functional cargo cabin, into orbit with a proton -K rocket. It also undertakes some military experiments, so the cabin is only allowed to be used by American astronauts. The launch and docking of the experimental module will mark the end of the second phase, when the space station has begun to take shape and can accommodate three astronauts for a long time; The third stage is to send the living module of the United States, the experimental module made by the European Space Agency and Japan, and the mobile service system of Canada into space. When these modules are docked with the space station, it marks the final completion of the assembly of the International Space Station. At this time, the number of astronauts on the space station can be increased to seven.

The United States, Russia and other countries 15 jointly build the International Space Station, which indicates that an era of joint exploration and peaceful development of space with other countries is coming. However, the achievements of manned space activities for decades are far from satisfying their desire for space. "The road is long and Xiu Yuan is awkward, and I will search up and down." Humans have always had the desire to conquer space and the determination to use space resources peacefully. 1998165438+10 In October, Glenn, the 77-year-old American astronaut who entered Earth orbit, once again set foot on a trip to space with his unswerving ambition, as if to tell mankind that conquering space at such a speed is not a dream.

The origin of astronomy can be traced back to the embryonic era of human culture. In ancient times, in order to indicate the direction and determine the time and season, people observed the sun, moon and stars, determined their positions, found out their changing laws, and compiled calendars accordingly. From this perspective, astronomy is one of the oldest natural science disciplines.

The content of early astronomy is essentially astrometry. Since Heliocentrism was put forward by Copernicus in the 16th century, the development of astronomy has entered a new stage. Previously, natural sciences, including astronomy, were severely bound by religious theology. Copernicus's theory liberated astronomy from the bondage of religion, and in the next century and a half, it developed from classical astrometry, which mainly described the position and motion of celestial bodies, to celestial mechanics, which sought the mechanical mechanism that caused this motion.

Copernicus (1473- 1543), a Polish astronomer, was the founder of Heliocentrism.

Galileo, an Italian astronomer, made the first astronomical telescope (1564- 1642).

Galileo is with his assistant.

The famous German astronomer Kepler (157 1- 1630).

Newton (1642- 1727), a famous physicist who invented the reflective telescope.

British astronomer Harley (1656- 1742).

French astronomer messier (1730- 18 17).

William Herschel (1738- 1822), the discoverer of Uranus, was a British astronomer.

American astronomer Edwin Hubble (1889- 1953).

Einstein, a famous physicist (1879- 1955).

Jansky, the founder of radio astronomy, is an American engineer who works in radio.

Astronomer Subrahmanyan Chandrasekhar (1910-1995).

18 and 19 century, classical celestial mechanics reached its peak. At the same time, due to the wide application of sub-optics, geodesy and photography, astronomy began to develop in the direction of in-depth study of the physical structure and process of celestial bodies, and astrophysics was born. Modern physics and technology developed rapidly in the 20th century, and found a wide range of applications in astronomical observation and research, making astrophysics the mainstream discipline in astronomy, and at the same time promoting the new development of classical astromechanics and astrometry. People's understanding of the universe and various celestial bodies and astronomical phenomena in the universe has reached an unprecedented depth and breadth.

Astronomy is essentially an observational science. All discoveries and research achievements in astronomy are inseparable from astronomical observation tools-telescopes and their back-end receiving equipment. Before the17th century, people had made many astronomical observation instruments, such as China's armillary sphere and simple instruments, but the observation work could only rely on the naked eye. 1608, the Dutchman Liporsay invented the telescope. 1609, Galileo made the first astronomical telescope and made many important discoveries. Since then, astronomy has entered the era of using telescopes. Since then, people have continuously improved the performance of telescopes in order to observe darker celestial bodies and obtain higher resolution. 1932, Jansky, an American, observed radio waves from celestial bodies with his rotating antenna array, which initiated radio astronomy. The first parabolic reflector radio telescope was born in 1937. After that, with the continuous expansion and improvement of the performance of radio telescope in terms of aperture, receiving wavelength and sensitivity, radio astronomical observation technology has made important contributions to the development of astronomy. In the last 50 years of the 20th century, with the development of detectors and space technology and the deepening of research work, astronomical observation has further expanded from visible light and radio bands to electromagnetic wave bands including infrared, ultraviolet, X-ray and γ-ray, forming multi-band astronomy, which provides a powerful observation means for exploring the physical essence and astronomical phenomena of various celestial bodies, and astronomy has developed to a brand-new stage.

As for the receiving equipment at the back end of the telescope,1In the mid-9th century, photography, spectroscopy and photometry were widely used in astronomical observation, which greatly promoted the exploration of the movement, structure, chemical composition and physical state of celestial bodies. It can be said that astrophysics has gradually developed into the mainstream discipline of astronomy after these technologies have been applied.

Astronomy differs from meteorology. Its research object is the nature of various celestial bodies outside the earth's atmosphere and various phenomena occurring on celestial bodies-astronomical phenomena, while the research object of meteorology is various phenomena occurring in the earth's atmosphere-meteorology. The Hong Kong Observatory also frequently broadcasts typhoon warnings, which is an exception.

Astronomy studies all kinds of celestial bodies in space, ranging from the moon, the sun, planets, stars, galaxies outside the Milky Way to the whole universe, to asteroids, meteoroids, and even large and small dust particles distributed in the vast space. Astronomers call all these objects celestial bodies. The earth is also a celestial body, but astronomy only studies the general properties of the earth and generally does not discuss its details. In addition, the motion properties of artificial aircraft such as satellites, spaceships and space stations also belong to the research scope of astronomy and can be called artificial celestial bodies.

The celestial bodies in the universe can be divided into several levels from near to far: (1) Solar system celestial bodies: including the sun, planets (including the earth), satellites of planets (including the moon), asteroids, comets, meteoroids and interplanetary media. (2) Various stars and clusters in the Milky Way: including variable stars, binary stars, multi-stars, clusters, nebulae and interstellar media. The sun is an ordinary star in the Milky Way. (3) Extragalactic galaxies, referred to as galaxies for short, refer to huge star systems similar to ours located outside our Milky Way galaxy, as well as large celestial bodies composed of galaxies, such as binary galaxies, multi-galaxies, galaxy clusters, supercluster clusters, etc. In addition, there are intergalactic media distributed between galaxies.

Astronomy also explores the origin, structure, evolution and future outcome of the universe as a whole, which is the research content of cosmology, a branch of astronomy. Astronomy can also be divided into astrometry, celestial mechanics and astrophysics according to the content of research.

Astronomy is always the forerunner of philosophy and always at the forefront of debate. As a basic research discipline, astronomy is closely related to human society in many aspects. The strict law of time, the alternation of day and night, and the change of seasons must be determined by astronomical methods. Mankind has entered the space age, and astronomy plays an irreplaceable role in the success of various space explorations. Astronomy has also made its own contribution to the disaster prevention and mitigation of human beings and the earth. Astronomers will also pay close attention to catastrophic astronomical events, such as the possibility that comets may collide with the earth, prevent them in time and make corresponding countermeasures.

nine planets

Objects and contents of astronomical research

Astronomy studies all kinds of stars and celestial bodies in space, ranging from the moon, the sun, planets, stars, galaxies outside the Milky Way to the whole universe, to asteroids, meteoroids, and even large and small dust particles distributed in the vast space. Astronomers call all these stars and celestial bodies celestial bodies. In this sense, the earth should also be a celestial body, but astronomy only studies the general nature of the earth and generally does not discuss its details. On the other hand, the motion properties of artificial aircraft such as satellites, spaceships and space stations also belong to the research scope of astronomy and can be called artificial celestial bodies.

Many people often can't tell the difference between astronomy and meteorology. It is common to call the observatory to ask about the weather. Perhaps astronomy and meteorology are confused by the study of "things in the sky". The Hong Kong Observatory frequently broadcasts typhoon warnings, which makes people mistakenly think that the Observatory is studying weather conditions. In fact, "Tian" in astronomical research and "Tian" in meteorological research are two completely different concepts. Astronomical "sky" refers to space, and meteorological "sky" refers to the earth's atmosphere. Astronomers study the nature of various celestial bodies outside the earth's atmosphere and various phenomena that occur on celestial bodies-astronomical phenomena, while meteorologists study various phenomena that occur in the earth's atmosphere-meteorology. Therefore, it is an astronomer's business to predict the occurrence of solar eclipse, lunar eclipse and meteor shower, while it is a meteorologist's duty to predict typhoon, high temperature and cold wave. With this in mind, it is not difficult to distinguish astronomy from meteorology.

We can divide the celestial bodies in the universe into several levels from near to far:

(1) Celestial bodies in the solar system: including the sun, planets (including the earth), satellites of planets (including the moon), asteroids, comets, meteoroids and interplanetary media.

(2) Various stars and clusters in the Milky Way: including variable stars, binary stars, multi-stars, clusters, nebulae and interstellar media. The sun is an ordinary star in the Milky Way.

(3) Extragalactic galaxies, referred to as galaxies for short, refer to huge star systems similar to ours located outside our Milky Way galaxy, as well as large celestial bodies composed of galaxies, such as binary galaxies, multi-galaxies, galaxy clusters, supercluster clusters, etc. In addition, there are intergalactic media distributed between galaxies.

Astronomy also explores the origin, structure, evolution and future outcome of the universe as a whole, which is the research content of cosmology, a branch of astronomy.

Astronomy can be divided into astrometry, celestial mechanics and astrophysics according to the research content. Astrometry is the earliest branch of astronomy, and its main content is to study and determine the position and motion of various celestial bodies and establish a celestial reference system. The observation data obtained from astrometry can not only be used for the research of astromechanics and astrophysics, but also have application value, such as determining the position of ground points. At present, the method of astrometry has developed from the early single visible light band to radio, infrared and other electromagnetic wave bands, and its accuracy has been continuously improved, and it has extended from the ground to space, which is space astrometry.

Celestial mechanics mainly studies the interaction, motion and shape of celestial bodies, in which motion should include the rotation of celestial bodies. The early research object was solar system celestial bodies, and now it has been extended to stars, clusters and galaxies. The establishment of Newton's law of universal gravitation and three laws of motion laid the foundation of celestial mechanics and made the research work develop from kinematics to dynamics. So Newton can be said to be the founder of celestial mechanics. Today we can accurately predict solar and lunar eclipses, which is inseparable from the development of celestial mechanics.

Astrophysics is the youngest branch of astronomy. It applies the techniques, methods and theories of physics to study the shape, structure, distribution, chemical composition, physical state, properties and evolution of various celestial bodies. /kloc-The stellar astronomy initiated by Herschel in the 0/8th century can be described as the gestation period of astrophysics. /kloc-in the mid-9th century, with the development of astronomical observation technology, astrophysics became an independent branch of astronomy, and made new discoveries and achievements in astronomical observation and research. As far as its research contents are concerned, there are solar physics, solar system physics, stellar physics, galactic astronomy, galactic astronomy, cosmochemistry, celestial evolution and cosmology. As far as its research methods are concerned, it can be divided into measurement astrophysics and theoretical astrophysics.

A brief history of astronomy development

The origin of astronomy can be traced back to the embryonic era of human culture. In ancient times, in order to indicate the direction and determine the time and season, people naturally observed the positions of the sun, the moon and the stars in the sky, found out the laws of their changes with time, and compiled calendars on this basis for life and agricultural production activities. From this perspective, astronomy is one of the oldest natural science disciplines. The content of early astronomy is essentially astrometry.

Since Heliocentrism was put forward by Copernicus in the 16th century, the development of astronomy has entered a new stage. Before that? /ca & gt；