Open classification of celestial bodies: space, universe, natural science, astronomy 1. Celestial bodies are all kinds of stars and interstellar substances, such as stars (including the sun), nebulae, planets (including Mars), satellites (including the moon), asteroids, comets and meteors.
All kinds of astronomical research objects formed by the polymerization of any cosmic matter. Such as the sun, planets, asteroids, satellites, comets, meteoroids and interplanetary substances in the solar system, stars, clusters, nebulae and interstellar substances in the Milky Way, and extragalactic galaxies, clusters, superclusters and intergalactic substances.
Infrared source, ultraviolet light source, radio source, X-ray source and γ -ray source discovered by radio exploration and space exploration are also celestial bodies. Man-made satellites, satellite rockets, space laboratories, lunar probes, planetary probes and interplanetary probes launched by humans and running in space are called artificial celestial bodies.
The position of celestial bodies The coordinates of celestial bodies in celestial coordinate system usually refer to their coordinates in equatorial coordinate system (right ascension and declination). Because the base plane (equatorial plane) and principal point (vernal equinox) of the equatorial coordinate system change with time due to precession and nutation, the right ascension and declination of celestial bodies also change.
In addition, the coordinates of celestial bodies observed by observers on the earth are also different because of their own motion and the spatial motion and position of the earth where observers are located relative to celestial bodies. The position of celestial bodies has the following definitions: ① Horizontal position.
The equatorial plane and vernal equinox, which only consider precession motion, are called flat equator and vernal equinox, and the coordinate system they define is called flat equatorial coordinate system, and the right ascension and declination measured with reference to this coordinate system are called flat positions. 2 true location.
Further consider that the equatorial plane and vernal equinox nutating relative to the flat equator and vernal equinox are called true equator and true vernal equinox, and the coordinate system defined by them is called true equatorial coordinate system, and the right ascension and declination measured with reference to this coordinate system are called true azimuth. Both the horizontal position and the true position change with time, and have nothing to do with the speed and direction of the earth's space movement and the relative position of celestial bodies.
③ Apparent position. Considering the above-mentioned spatial factors of the earth relative to the celestial body at the observation time, the position obtained by correcting the influence of aberration and parallax on the true position of the celestial body is called the apparent position.
The apparent position is equivalent to the equatorial coordinates of the observation time directly measured by the observer on the imaginary earth without atmosphere. The sky * * * set listed in the catalog is usually the horizontal position relative to the selected time (called the catalog epoch).
In order to obtain the apparent position of instantaneous observation, it is necessary to supplement: ① precession and self-correction from the epoch of catalog to instantaneous observation. ② Observation instantaneous nutation correction.
③ Correction of observed instantaneous aberration and parallax. The distance between celestial bodies and observers on earth.
The distance between different types of celestial bodies is very different, and the measurement methods are also different. (1) The celestial bodies in the solar system are the latest kind of celestial bodies, and the adjustment between the moon and the planets can be determined by triangulation. According to the celestial mechanics theory, the solar parallax is obtained.
You can also send radio pulses or laser beams to the moon or planets, and then receive the echoes reflected from their surfaces, record the round-trip time of radio waves and directly calculate the distance between celestial bodies. (2) For the close-range celestial bodies outside the solar system, the triangular parallax method is only applicable to the stars within 100 parsec from the sun.
The triangular parallax of distant stars is too small to be measured, so the distance should be measured indirectly by other methods. It mainly includes: analyzing some spectral lines of the star spectrum to estimate the absolute magnitude of the star, and then calculating its distance by comparing the absolute magnitude and apparent magnitude of the star; Analyze the intensity of interstellar absorption line in the star spectrum to estimate the distance of the star; The distance of the visual binary star is calculated by using the observed orbital period and orbital opening angle of the visual binary star. The distance of the moving cluster is calculated by measuring the position of the radiation point and the self-propulsion and apparent velocity of the member stars. For a group of stars with certain characteristics, the average distance of these stars is estimated according to their own average; According to the principle that the differential rotation of the Milky Way is related to the apparent velocity of stars, the average distance of clusters is calculated from the measured value of the apparent velocity.
③ The methods for measuring the distance of distant objects outside the solar system mainly include: apparent magnitude observed by RR variable star in Lyra; Using the period-luminosity relationship of Cepheid variable stars; Using the angular diameter measurement of globular clusters or galaxies; Using the comparison between the main sequence stars of the cluster to be measured and the main sequence stars of the known stars; Using the observed maximum apparent magnitude of nova or supernova; Using the observed average apparent magnitude of bright stars in extragalactic galaxies; Accumulate apparent magnitude by using observed globular clusters; Using the redshift of galaxy spectral lines and Hubble's law. The shape and rotation of celestial bodies have a certain size and shape because celestial bodies are not particles. The mutual attraction between particles in celestial bodies and the centrifugal force of rotation change the shape and density distribution of internal substances, and also affect the rotation motion of celestial bodies.
The theory of celestial body shape and rotation mainly studies the law of celestial body shape and rotation under the action of universal gravitation. In the theory of celestial body shape, celestial bodies are usually regarded as incompressible fluids, and the equilibrium shape and stability of celestial bodies when rotating under uniform or uneven density distribution are discussed.
At present, the most in-depth study is the theory of earth shape, and the earth models such as rotating ellipsoid and balanced shape triaxial ellipsoid are established. In recent years, the data obtained by using artificial satellites dedicated to earth survey are matching the results of ground geodesy to establish a more accurate earth model.
The theory of celestial rotation mainly discusses the motion of celestial rotation axis in space and body and the change of rotation rate. Among them, the theory of earth rotation is discussed in great detail.
The movement of the earth's rotation axis in the body forms a pole shift (see pole shift); At the same time, the orientation of the earth's rotation axis in space is also changing (see precession and nutation). The speed of the earth's rotation is also changing. It has a long-term deceleration, which makes the sidereal day length increase by about11000 seconds every1000 years, and there are some short-term and irregular changes (see Earth's rotation).
Celestial bodies are the knowledge of physics in the next semester, and there are many related contents in some study materials.
2. Sports celestial sports related test sites
One.
Kepler's third law: T2/R3=K(=4π2/GM){R: orbital radius, t: period, k: constant (independent of the mass of the planet, depending on the mass of the central celestial body)} II. Law of gravitation: F=Gm 1m2/r2 (G=6.
67* 10- 1 1N？ M2/kg2, the direction is on their connection) 3. Gravity and gravity acceleration on celestial bodies: GMm/R2 = mg；; G=GM/R2 {R: celestial radius (m), m: celestial mass (kg)} 4.
Orbital velocity, angular velocity and period of the satellite: v = (GM/R)1/2; ω=(GM/R3) 1/2； T=2π(r3/GM) 1/2{M: mass of central celestial body} V. First (second and third) cosmic velocity v 1 =(g- Earth and R- Earth) 1/2 =(GM/R- Earth).
9 km/s; V2 =11.2km/s; V3= 16 .
Seven kilometers per second six. Geosynchronous satellite GMM/(r+h) 2 = M4 π 2 (r+h)/T2 {h ≈ 36,000 km, h: height from the earth's surface, r: radius of the earth} Note: (1) The centripetal force required for celestial movement is provided by gravity, with direction F =F million; (2) The mass density of celestial bodies can be estimated by applying the law of universal gravitation. (3) Geosynchronous satellites can only run over the equator, and the running period is the same as the earth's rotation period; (4) When the orbit radius of the satellite decreases, the potential energy decreases, the kinetic energy increases, the speed increases and the period decreases. (5) The maximum circling speed and minimum launching speed of the Earth satellite are both 7.
9 kilometers per second.
Who can tell me something about celestial bodies and astronomy, such as black holes and silver?
Black holes are celestial bodies with strong gravity, and even light can't escape. When the radius of a star is smaller than that of schwarzschild radius, even the light emitted from a vertical plane cannot escape. At this time, the star becomes a black hole. To call it "black" means that it is like a bottomless pit in the universe. Once something falls in, it seems that it can't escape. Because the light in the black hole can't escape, we can't directly observe the black hole. But we can indirectly observe or infer its existence by measuring its effect and influence on the surrounding celestial bodies. The extension of a black hole means the inevitable. 20 1 1 February, astronomers first observed the process of black holes "capturing" nebulae. The process of black holes is similar to that of neutron stars. When a star is ready to die, its core shrinks, collapses and explodes rapidly under its own gravity. When all the matter in the core becomes neutrons, the contraction process stops immediately, it is compressed into a dense star, and the inner space-time is also compressed. But in the case of a black hole, because the mass of the star core is so great that the contraction process goes on endlessly, and the neutron itself is ground into powder under the attraction of the squeezing gravity itself. What's left is an incredibly dense substance. Due to the force generated by high quality, anything near it will be sucked in by it. Black holes began to devour the shells of stars, but black holes could not devour so much matter. Black holes will release some substances, releasing two kinds of pure energy-gamma rays. It can also be simply explained that stars originally only contain hydrogen, and hydrogen atoms inside stars collide with each other all the time. Fusion happened. Because of the great mass of stars, the energy generated by fusion competes with the gravity of stars to maintain the stability of star structure. Due to fusion, the internal structure of hydrogen atoms eventually changes and breaks, forming a new element-helium, and then helium atoms also participate in the fusion, changing the structure and generating lithium. By analogy, beryllium, boron, carbon and nitrogen will be generated in turn according to the order of the periodic table of elements. The star will collapse. This is because iron is quite stable and can't participate in fusion, but it exists inside the star, which leads to insufficient energy inside the star and can't compete with the gravity of the massive star, which leads to the collapse of the star and eventually forms a black hole. To call it "black" means that it is like a bottomless pit in the universe. Once anything falls in, it can't escape. Like white dwarfs and neutron stars, black holes may have evolved from stars several times the mass of the sun. A black hole with strong gravity. When a star ages, its thermonuclear reaction has exhausted the fuel (hydrogen) in the center, and the energy generated in the center is not much. In this way, it no longer has enough strength to bear the huge weight of the shell. So under the weight of the shell, the core begins to collapse, and the material will move towards the center inexorably. Until it finally forms a star with infinitely small volume and infinite density. When its radius shrinks to a certain extent (it must be smaller than schwarzschild radius), the space-time distortion caused by mass makes it impossible for even light to escape-a "black hole" is born.
How much do you know about the universe?
The primitive universe is a geometric point with infinite mass, with no time and no space.
At the moment when this "point" exploded, time began and space (universe) came into being. This "point" (now called the universe) is constantly expanding, and the space of the universe is getting bigger and bigger.
Now the universe is still expanding, which is discovered through the phenomenon of red shift. What is the redshift phenomenon? That is, when an object leaves us, the frequency of light emitted by this object is received by us, and the frequency of light has been reduced.
It is equivalent to that the object originally emits purple light, but when we see it, it has turned into red light. This phenomenon is the "Doppler" effect.
The big bang theory is a conjecture. Time and space, energy and mass, speed and mass of motion, and speed and speed of motion are all studied in Einstein's general theory of relativity.
The wisdom of the universe and the origin of human beings are very confusing to human beings. One is that human beings are very unique in the universe, because in other places outside the earth, human beings have never found a small intelligent life similar to ours. It seems that accidents are allowed in the universe; On the other hand, the universe shows its standardization everywhere.
Some basic principles are very common in the universe, so the universe should not be a place to deliberately create accidents. The evolution of life has lasted for 4 billion years. Are these four billion years really gradual? It's nuclear energy-more than 65438+ billion kilometers away from the earth, many nuclei keep colliding, and it took 5 billion years to create life and achieve the ultimate intelligent life.
However, this evolution is not gradual as most people think. The simplest life appeared 4 billion years ago, but it is such a simple state of life that has existed silently on the earth for about 3.5 billion years. It was only at this stage of 535 million years that people discovered creatures larger than microorganisms.
This evolution seems to be sudden, even explosive. There are Earth and Venus in the solar system. Who gave the earth the only chance to have life? In fact, in the solar system, besides the earth, Venus is the most likely place for life.
Because it is almost as big as the earth. The conditions for the existence of water are also fully satisfied.
But luck finally fell on the earth, mainly because of the gravity and temperature of the earth. The current sun temperature is obviously a little too hot for Venus, but it is very suitable for the earth.
However, as long as the temperature of the sun changes slightly, it will be suitable for Venus and not for the earth. Humans have evolved for tens of thousands of years. Is the brain also evolving? The super information processor of human brain is the most perfect intelligent structure in the universe at present.
This thing that the universe gave us seems to be very advanced. It is said that the human brain has not evolved from ancient primitive state to modern high-tech thinking. The brain we use today is not much different from that of 30,000 years ago. Generally speaking, we only use 65,438+00% of the whole brain potential.
In the early 1980s, the most popular expanding universe model was developed under the framework of the Big Bang: the universe expanded by about 1 0-30 times in less than1second after the Big Bang, about the size of an orange, and then began to expand at a relatively stable speed. Until now, it has become today's1500 million years. In this process, matter "bulges" gradually formed galaxies, stars and life.
The length of the expansion period of this model is a key. A little shorter, the matter will all be scattered, and the original universe will collapse again from this as a starting point; If it were a little longer, the matter in the original universe would be too dispersed to form galaxies and stars, and naturally there would be no life and human beings.
Therefore, the question of why inflation is so accurate arises. According to the current basic laws of physics, the "natural size" of the universe generated by the Big Bang should only be subatomic, that is, the Pockrone length is 10-35, and such a universe is short-lived. Linde, a former Soviet scientist, put forward the concept of "self-propagating universe"-"It is very likely that the universe we are studying was formed by several early universes."
1987, Hawking further proposed the "baby universes" model, in which two universes are connected by a thin "tube", which is called a "wormhole". The universe is the mother universe, and there may be wormholes branching from the mother universe, and the other end is free. Such a tube becomes a sub-universe and a baby universes. In other words, besides our universe, there may be many other universes connected by wormholes.
1992, Satsumahayashi put forward the theory of natural selection in the universe on the basis of predecessors. Mother Universe is enclosed in space, just like a black hole. After living for a period of time, the black hole collapses into a singularity, and the singularity will rebound and explode, expanding into a new next-generation universe.
The main point of this theory is that the physical constants in the sub-universe will change randomly, small or strong or weak compared with the mother universe, and the newly born baby universes can expand to several times the length of Pockrone before it collapses into a singularity again. The physical constant of random mutation may allow a small expansion, and the sub-universe may be larger. When it is large enough, it can be divided into two or more different regions, and each region collapses into a new singularity. Novelty also triggered the next generation of sub-universe. According to the legend of the times, some small universes collapse again, and some universes with some basic constant values can produce many black holes more effectively, thus leaving more descendants than those with other basic constant values. Borrowing the term of biological evolution, they are "naturally selected", and through the "selection" effect, more and more black holes are produced and more universes are formed. If the universe is indeed produced by the previous generation of the universe through this "natural selection", then it should be expected that the universe we live in will have an observed appearance and just have the basic constant values measured at present.
Another point of this theory is about the existence of stars. In many cases, stars are the precursors of black holes.
Stars are still forming in clouds of gas and dust. The chemical reaction on the surface of carbon dust particles cooled the gas, causing the gas cloud to collapse.
But where do carbon dust particles come from? Smolin pointed out that carbon is produced by nuclear fusion reaction, which only happens when the proton mass is slightly greater than the neutron mass.
5. Urgently seek knowledge about the motion of celestial bodies.
This classmate, you seem to be talking about photonics in quantum mechanics.
Interpretation of quantum mechanics
We know that from the point of view that photons are the basic particles of matter, the composition of matter itself is meaningless. If matter can't interact with other photon information in the environment, it can't express its energy, existing form and properties. It exists in the form of pure dark matter. Although its life span is infinite, it is meaningless to the environment and itself. Only by constantly interacting with other photon information in the environment can it show its energy and quality. That is to say, any matter, as long as it exists, will constantly interact with other photon information in the environment, so that the existence of matter and all kinds of forces are actually completed through the photon information field around it.
As shown in the figure, the existence of substance A is the photon information energy that substance A constantly interacts with the environment, showing its own quality. When substance B exists, because B also constantly interacts with the photon information of the environment, this B affects the photon information content around A to varying degrees. From a macro point of view, it is B that blocks the photon information from around A and changes the photon information field around A. From a macro point of view, the photon information from the left has more energy and the photon information from the right of A has less energy. Macroscopically, B has a force on A, which is possessed by all substances and is called gravity.
In other words, because of the existence of B, the shape of the photon information field around A has changed, and the shape of this field has also changed. When there is no B, object A is in equilibrium. With B, the photon information field has changed, and the force of object A has become unbalanced. People will naturally say that this is the result of the existence of object B and the force of object B on A.
6. Astrophysics knowledge
Discussion on the evolution of celestial bodies in the universe: the colorful cloud-like "nebula" in the deep starry sky, the "comet" with a long tail, and the sun and moon closely related to us are all composed of the same substance (more than 100 elements in the periodic table), although their shapes are different.
The reason why there are different forms is that planets are in different stages of evolution and the composition ratio of elements is different. When a planet is mainly composed of chemically unstable elements such as hydrogen and oxygen, the nucleus of the planet reacts violently, and the planet is in the initial stage of celestial evolution-the star stage; When the proportion of chemically stable elements such as silicon and iron in a planet increases, the nuclear reaction gradually weakens and it is in the late stage of celestial evolution-planetary stage.
Planets evolved from stars, comets and asteroids evolved from planets. The evolution of every planet in the universe goes through several stages: black holes, nebulae, stars, red giants, white dwarfs, planets, comets and asteroids.
Planets are * * * the same sex and different, even at the same stage of evolution, their forms are not exactly the same. According to the known astronomical data, this paper expounds the evolution process of the universe and planets as follows: the universe is composed of constantly moving substances. When matter moves, due to the differences in direction, speed and density, there will be countless magnetic eddies (that is, "black holes") of different sizes. When the matter in the star-level "black hole" gathers in one direction and moves in an orderly way at an extremely fast speed, the energy and gravity generated will attract gaseous substances such as hydrogen and oxygen and substances such as silicon and iron to spread into the universe.
"Nebula" is a ring-shaped or mass-shaped celestial body condensed by thin gas and dust. With the constant attraction and swallowing of the surrounding materials, the volume and density of the "nebula" reach a certain critical value, which has two important conditions for the nuclear fusion reaction of hydrogen atoms (one is that the celestial body reaches a considerable volume; Second, when the hydrogen element in the celestial body reaches a certain density, the hydrogen atoms in the dense central region (star core) of the "nebula" begin to undergo a fusion reaction under the action of the huge friction force generated by the celestial movement, and a huge energy is erupted, and the "nebula" evolves into a "star" that can emit intense light and heat. A "star" is huge, and hydrogen accounts for the vast majority. The nucleus reacts violently, with great energy and strong radiation, producing strong magnetic field and gravity, which can attract some celestial bodies with relatively small mass and form galaxies centered on them.
The evolution of the "star" stage will last for at least tens of billions of years, and the sun is in the middle stage of the evolution of stars. As the consumption of hydrogen in the star decreases gradually, the nuclear reaction of the star becomes weaker and weaker, and eventually it becomes a "red giant".
The basic characteristics of "red giant star" are that the internal attraction of the star decreases, the components expand outward, the volume becomes very large, and the ratio of helium to oxygen in the surface layer increases, so the degree of luminescence and heat generation is lower than that of the star, but a solid shell has not yet formed. When the surface material of the "red giant star" was lost in the supernova explosion, the surface temperature of the star core dropped to a certain extent. In the ultra-high temperature environment, silicon and iron, which were originally gaseous and liquid, condensed into a solid state due to the temperature drop, and began to form a solid shell in the outer layer of the first cooled star core, and then gradually evolved into a celestial body-a "white dwarf star" that could not emit light radiation by itself. The volume is greatly reduced (it can be reduced by hundreds of thousands of times), and a large amount of hydrogen is compressed in the shell. Therefore, although the "white dwarf" is small in size, its relative mass is large, its internal material density is high, and its magnetic field and gravity are still very strong. Then, with the change of the balance of mutual attraction and centrifugal force with other stars and other celestial bodies, it enters the "planet" stage.
The stage from "white dwarf" to "planet" is a process in which the solid shell of a planet keeps expanding and the gaseous and liquid surface substances composed of hydrogen and oxygen elements keep decreasing. Like Jupiter, the early planets were surrounded by a very thick and dense atmosphere.
In the middle stage of a planet similar to the earth, life will appear and exist on the planet during this period because of the continuous decrease of the surface temperature and the suitable conditions such as the ratio and temperature of hydrogen, oxygen and nitrogen in the atmosphere. Because the huge energy generated by the nuclear reaction inside the "planet" will gradually accumulate a lot of pressure, every once in a while, when the shell can't bear it, the internal energy breaks through the shell to form an explosion, and a large amount of hydrogen and oxygen elements are discharged into the universe. At the same time, the volume of the planet expands, the solid shell thickens, and the surface environment will change greatly.
After many explosions, the hydrogen and oxygen elements of the planet were further reduced, and the internal nuclear reaction became weaker and weaker, entering the later stage of the planet like Mars. Although the surface of Mars has a thin atmosphere and a small amount of solid water (white polar cap), there is no life-supporting environment.
Recent exploration has found traces of rivers on Mars, and it is very likely that conclusive evidence of the existence of life will be found in future exploration. When the hydrogen and oxygen elements of the planet basically disappear, the nuclear reaction basically ends, the gravity gradually weakens, and the centrifugal force of the planet's constituent substances exceeds the gravity, the balance between the internal and external structures is broken, and the planet begins to break up and enter the final stage of planetary evolution-"comet" is the main form of this stage.
Because the comet nucleus still has a certain attraction, it can form a group of celestial bodies (such as Halley's comet) that move around the star, and eventually the comet will be completely dispersed into a single celestial body fragment of different sizes-asteroids. According to observation, this kind of celestial debris exists in a large number in the universe.
When the scattered matter in the universe is attracted by the vortex (black hole) of the cosmic magnetic field, a new round of celestial evolution begins again.
7. Where can I learn about the stars in the universe?
According to foreign media reports, the Hubble Space Telescope has made another important discovery-it has observed the largest and heaviest star in the universe so far.
The diameter of this giant star is more than 1 14 times the diameter of the sun. It is part of a binary star system-its "companion star" is much smaller. The mass of this star is 150 times that of the sun.
Experts support that this is the first time such a huge star system has been observed in human history. According to the current popular theory, the mass of a star hardly exceeds 100 times that of the sun.
The largest star ever discovered is 83 times the mass of the sun. This new star is now named a 1.
It is located in the central area of ngc 3603 galaxy cluster, 200,000 light years away from the Earth. The companion star of a 1 should not be underestimated-its mass is 84 times that of the sun.
Astronomers say they "weigh" the mass of a 1 by observing the orbits of two giant stars. It should be pointed out that according to the existing theory, the ultimate mass of a star is 150 times that of the sun. Beyond this limit, stars will be too unstable to exist.
Scientists also pointed out that there are some stars in the early universe with hundreds of times higher mass than the sun, but this requires certain conditions-early stars only contain two elements: hydrogen and helium. In addition, not long ago, British astrophysicists discovered the star with the lowest temperature so far.
This celestial body is undoubtedly among the stars in all aspects, but its surface temperature is only one tenth of that of the sun. Scientists say that this strange celestial body is the coldest brown dwarf star-this celestial body is an "underdeveloped" star, and due to its own lack of mass, it cannot create enough temperature inside to lead to thermonuclear fusion.
British media reported that this strange celestial body has been named j0034-00. According to scientists' calculations, the surface temperature of a star is only about 430 degrees Celsius-which is really too low for a star.
The researchers pointed out that j0034-00 is the lowest temperature among the known stars. Experts say that j0034-00 is one of the few transitional links connecting large gaseous planets with the smallest stars.
Dr Steve Warren from Royal College London said: "Physically, brown dwarfs and large gaseous planets belong to the same category. But at the same time, finding such a planet is much more complicated. "
It is reported that the star j0034-00 is located in the constellation Cetacea. In other respects, j0034-00 is a "real" star: its mass is 15-30 times that of Jupiter, but their diameters are almost the same.
The successful discovery of this celestial body is also attributed to the ukirt infrared astronomical telescope deployed in Hawaii. Scientists also admit that the discovery of j0034-00 was very accidental-the researchers took more than 2,000 photos with the help of four different filters.
At first, experts also studied quasars. Daniel Mortlock, who participated in the research, said: "Although it is strange, although the distance between celestial bodies and the earth is only one billion times that of quasars, it is more difficult to observe."
In the near future, scientists will also use more powerful telescopes to identify other low-temperature stars similar to j0034-00, which are no more than 50 light-years away from the Earth.