Little knowledge of the universe, 300 words

1. Eight little knowledge about the universe

Eight little things about the universe 1. Little is known about the universe.

Constellation division Aries: March 2 1 to April 20 Taurus: April 2 1 to May 2 1 Gemini: May 22 to June 2 1 Cancer: June 22 to July 22 Leo: July 23 to August 23 Virgo:: 655. Kloc-0/October 22nd Sagittarius:165438+1October 23rd ~ 65438+February 20th.

As the earth revolves around the sun, from the perspective of the earth, the sun seems to move between constellations. People call the running route of the sun the ecliptic, and the running tracks of the moon and planets basically do not leave the narrow area of 9 degrees above and below the ecliptic, so people call this area the ecliptic. There were twelve zodiac signs in ancient times, and the sun basically passed one zodiac sign every month, so it was called the zodiac.

After the day, due to precession, the date when the sun passes through the zodiac is very different from that in ancient times. Introduction to Mercury Mercury is the closest planet to the sun, and its angular distance from the sun has never exceeded 28. In ancient China, Mercury was called a star.

In ancient times, Westerners thought that Mercury was two planets. When they see it at dusk, they call it mercury, and when they see it at dawn, they call it Apollo. Later, people knew that Mercury and Apollo were the same star, so they called Mercury Mercury.

Mercury was a special messenger in Roman mythology who sent messages to the gods. He wears a hat with wings, flying shoes and a wand, and walks like a fly. He is omnipotent and unpredictable.

Mercury, like mercury, is really changing and elusive. In another month and a half, it will run from the easternmost end of the sun to the westernmost end, with an average speed of 47.89 kilometers per second, making it the fastest moving planet in the solar system. Venus is a simple introduction to Venus, which was called Taibai or Taibai Venus in ancient China.

It is sometimes the morning star, which appears in the eastern sky before dawn and is called "Qi Ming". Sometimes it is a dim star, which appears in the western sky after dusk and is called Chang Gung. Venus is the brightest star in the whole day except the sun and the moon, just like a dazzling diamond, so the ancient Greeks called it Aphrodite, the goddess of love and beauty, while the Romans called it Venus, the god of beauty.

In astronomy, the symbol of Venus is the precious mirror used by the beauty god when dressing. The earth is one of the nine planets in the solar system, and the third planet is arranged in the order from near to far from the sun.

It has a natural satellite-the moon, forming a celestial system-the earth-moon system. From near to far from the sun, Mars is the fourth planet.

To the naked eye, it is a striking bright lux star. It travels slowly among the stars. When looking at Mars from the earth, it sometimes goes straight and sometimes goes backwards.

The darkest apparent magnitude of Mars is about+1.5, etc. And at the brightest time, it is brighter than the brightest star Sirius, reaching -2.9. This is because the Earth and Mars are in their respective orbits, and the distance between them is always changing. Mars is as bright as fire, its brightness is constantly changing and its position is uncertain, which is confusing. So China called Mars "sparkling" in ancient times.

In western ancient Roman mythology, it was imagined as Mars, the god of war in armor and covered in blood, that is, Ares in Greek mythology. Ares had a noble life. His father is Zeus, the king of the gods, and his mother is Hera, the queen of heaven.

Astronomically, the symbol of Mars is the combination of the spear and shield of Mars. Introduction to Jupiter Jupiter is the most striking planet in the solar system. It is the oldest and largest of the nine planetary brothers.

Its brightness is second only to Venus. In ancient China, it was called the "year-old star", which was used to date the years because it was known that its period of revolution was close to 12.

The west calls Jupiter "Jupiter", the main god in Roman mythology. Equivalent to the king Zeus in Greek mythology.

Saturn is a beautiful planet, the sixth farthest from the sun. Anyone who has seen Saturn through a telescope will be surprised. Saturn's orbital radius is 65.438+0.4 billion kilometers, and its maximum brightness is 0.4 magnitude when it hits the sun.

On Saturn's orange surface, there are bright and dark clouds floating, and the soft and shiny halo on the equatorial plane looks like a girl wearing a sun hat from a distance. It is more than 6000 kilometers larger than the radius of the poles.

Saturn's period of revolution is 29.5 years, which is about 28 nights. It stays in the town for one night every year, so it was also called "Town Star" in ancient China. Saturn has always been regarded as the boundary of the solar system, and it was not until Uranus was discovered in 178 1 that the solar system began to expand.

Saturn moves slowly, so people regard it as a symbol of time and fate. In Roman mythology, he was called the Saturnalia, that is, Cronus in Greek mythology. He is the father of Zeus, the king of the gods, who overthrew his father and ascended the throne of the gods.

Both the East and the West associate Saturn with agriculture. Symbols in astronomy are like scythes that dominate agriculture.

Introduction to Uranus It is not difficult to watch Uranus on a clear night. Its magnitude is 5.7.

Its period of revolution is quite long. It orbits the sun once every 84 years, moving only 46 inches a day on average. It is not easy to distinguish it from a star. In history, it has been mistaken for many times that stars are loaded into star maps. Introduction to Neptune The average distance from the sun is arranged from near to far, and Neptune ranks eighth.

Its brightness is 7.85 and so on, which can only be seen in a telescope. Because it is a light blue planet, it is named Neptune according to the traditional planetary nomenclature.

Neptune is the sea god who rules the ocean in Roman mythology. He is in charge of the universe of13, which is quite amazing. Neptune's astronomical symbol symbolizes the cold shiny fork in Neptune's hand. Asteroids refer to small celestial bodies that are mostly distributed between the orbits of Mars and Jupiter and orbit around the sun along elliptical orbits.

180 1 year, Italian astronomer Piazi discovered a star in the position predicted by his predecessors, and later named it ceres. However, after further observation and calculation, it is found that Ceres is too small to be compared with the existing planets in any case, so Ceres is characterized as an "asteroid".

Then people discovered pallas Athena, Vesta, Vesta and other asteroids.

I want to use a little knowledge about the universe.

Outer space refers to the space outside the dense atmosphere of the earth, and there is no clear boundary. ordinary

It is defined as the space about 1000 km from the earth's surface. Human curiosity and exploration of outer space have never been

No, the successful launch of China's "Shenzhou 5" and "Shenzhou VI" indicates that China's exploration of outer space has gone global.

Advanced ranks in the world.

Outer space is referred to as space for short, also known as cosmic space, which refers to the outer atmosphere relative to the earth's sky.

Void area, outer space is usually used to distinguish it from airspace (territory); Although it is empty, it is not nothing.

Hmm.

There is no clear boundary between space and the earth's atmosphere, because the atmosphere gradually becomes thinner with the increase of height. wrong

Assuming that the atmospheric temperature is fixed, the atmospheric pressure will increase exponentially from 1000 mbar at sea level with the increase of altitude.

Reduce to zero

The height of 100 km is defined as the Carmen line by the International Aviation Federation, which sets the boundary between the atmosphere and space.

Justice. The United States recognizes that people who reach an altitude of 80 kilometers are astronauts. 120 during the spacecraft's return to Earth.

Kilometers is the boundary where air resistance comes into play.

3. Knowledge about the universe

In Chinese, "Yu" stands for up and down four directions, that is, all the space, and "Zhou" stands for all the time, that is, all the time. Yu: infinite space, and Zhou: infinite time.

So the word "universe" has the meaning of "all time and space". Linking the concept of "universe" with time and space embodies the wisdom of the ancient people in China.

The word "universe" comes from the book Zhuangzi. "Yu" refers to all spaces, including all places in the east, south, west and north, which are boundless; "Week" refers to all time, including past, present, day and night, with no beginning and no end. In the west, the word universe is called co * * * OS in English, UNIVERSE, space in Russian, ko *** os in German and co *** os in French.

Are derived from the Greek κoσμoζ. The ancient Greeks believed that the universe was created to produce order from chaos, and the original meaning of κoσμoζ was order. But in English, the more commonly used word for "universe" is Universe.

This word has something to do with universitas. In the Middle Ages, people called universities a group of people who acted in the same direction and goal.

In the broadest sense, universitas also refers to a unified whole composed of all ready-made things, that is, the universe. Universe and co *** os often express the same meaning, but the difference is that the former emphasizes the sum of material phenomena, while the latter emphasizes the structure or construction of the whole universe.

"Yu" refers to space and "Zhou" refers to time. The universe is a material world with infinite space, no beginning and no end of time, and moving according to objective laws. The universe summarizes that the universe is a unity composed of space, time, matter and energy. The universe is the general name of all things, and it is the unity of time and space.

The universe is a material world, which exists objectively regardless of human will and is in constant movement and development. The universe is diverse and unified; Diversity of material manifestations; Unity lies in its materiality.

Understanding different levels of the universe from a philosophical point of view. People think that the universe has no beginning, no end and no end.

However, we are not going to discuss this abstruse concept in depth, so let's leave it to philosophers to study. We might as well squint and use our existing science and technology to talk about the universe that we can understand and observe. People call it "our universe" or "total galaxy".

According to the latest observation data, the farthest galaxy observed by people is 65.438+0.3 billion light years. That is to say, if a beam of light is emitted from a galaxy at a speed of 300,000 kilometers per second, it will take 654.38+03 billion years to reach the earth, which is of course 654.38+03 billion years ago.

This distance of 65.438+0.3 billion light years is the universe we know today (2009). More specifically, the universe as we know it today, or its size, is a spherical space with the earth as the center and the distance of 65.438+0.3 billion light years as the radius.

Of course, the earth is not really the center of the universe, and the universe is not necessarily a sphere. It's just limited to our current observation ability, and we can only know this extent. In this spherical space with a radius of1300 million light years, there are about1250 million galaxies that have been discovered and observed, and each galaxy has hundreds to trillions of sun-like stars.

So as long as you do a simple math problem, it is not difficult for you to know how many stars there are in the universe we have observed. In such a vast universe, the earth is really a drop in the ocean and insignificant.

Astronomers have always wondered how big the universe is, just like us. Recently, the American Space Network reported that after hard calculation, astronomers found that the universe is extremely huge, with a length of at least 65.438+056 billion light years.

"Such a discovery about the size of the universe is obviously based on the premise that the universe is spherical and limited. This assumption was first put forward by Einstein. "

Daming Chen, a researcher at the National Astronomical Observatory of China, said in an exclusive interview with reporters, "For a long time, there has been such a debate in the field of cosmology, whether the universe is spherical, saddle-shaped or flat." Zhang Yue, an associate professor at Beijing Normal University, said: "The international mainstream cosmology generally believes that the universe is flat and infinite."

So, where does the debate around the universe come from? What makes sense? The most common view is that after the Big Bang, the universe was born. "According to the most influential Big Bang theory in modern cosmology, our universe was produced by a very small point explosion about 65.438+0.37 billion years ago, and the universe is still expanding."

Researcher Daming Chen said, "This theory has been confirmed by a large number of astronomical observations." This theory holds that in the early days of the birth of the universe, the temperature was very high. With the expansion of the universe, the temperature began to drop, producing neutrons, protons and electrons.

Since then, these elementary particles have formed various elements. These particles attract and fuse with each other, forming larger and larger clumps, and gradually evolving into galaxies, stars and planets. Life phenomena have appeared on individual celestial bodies, and finally human beings who can understand the universe have been born. Is the universe spherical and finite? "The idea that the universe is spherical has existed for a long time, although it is not the mainstream of the international cosmology community."

Daming Chen said, "Every time it is mentioned, it will attract people's attention, because this view is very strange." One of the most obvious examples is the universe model established by American mathematician Jeffrey Wilkes not long ago: a mirror maze of limited size, shaped like a football.

The model of "shaped like a football" shocked the scientific community, because this theory claimed that the universe produces an "illusion" without boundaries because this limited space reflects itself endlessly through the "circle" effect. Wilkes believes that people think that the universe is infinite because the universe is like a mirror maze, and light shuttles back and forth, giving people the illusion that the universe is infinitely extended.

This amazing inference was later included in New Scientist magazine and widely circulated among the people as a kind of "strange talk". [Edit this paragraph] Cosmic age Cosmic age defines the universe.

For some models of the universe, such as cows.

4. A little common sense about space, introduce space.

The space outside the earth's atmosphere, the whole space outside the atmosphere. space

Physicists divide the atmosphere into five layers: troposphere (sea level to 10km), stratosphere (10 ~ 40km), mesosphere (40 ~ 80km), thermosphere (ionosphere, 80 ~ 370km) and outer atmosphere (ionosphere, over 370km). About 3/4 of the atmosphere above the earth is in the troposphere, and 97% is below the stratosphere. The outer edge of the stratosphere is the highest limit for an aircraft to fly with air support. Some high-altitude rockets can enter the middle layer. The lowest orbit of the satellite is in the thermocline, and its air density is 1% of the earth's surface. At the height of 16000km, air continues to exist, and even at the height of 10000km, there are still air particles. From a strictly scientific point of view, there is no clear boundary between airspace and outer space, but they are gradually integrated. The Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space pointed out that it is impossible to put forward accurate and lasting scientific standards to divide the boundary between outer space and airspace. In recent years, people tend to take the minimum height of artificial satellites from the ground (100 ~110) km as the lowest limit of outer space.

5. Knowledge about the universe

Cosmic knowledge: a brief introduction to the theory of natural selection in the universe

Why is the universe what we observed? Why does it have those basic constant values measured so far? 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 mass of protons is slightly greater than that of neutrons. If the difference between them is much greater than the binding energy of helium nuclei, protons and neutrons cannot stick together to form helium nuclei. Without helium, the fusion reaction chain will end in the first stage, and there will be no heavier elements at all, so there will be far fewer stars and naturally there will not be many black holes. Therefore, in any universe, if protons and neutrons have different masses,

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6. There is little knowledge about space.

The space outside the earth's atmosphere, the whole space outside the atmosphere. Physicists divide the atmosphere into five layers: troposphere (sea level to 10km), stratosphere (10 ~ 40km), mesosphere (40 ~ 80km), thermosphere (ionosphere, 80 ~ 370km) and outer atmosphere (ionosphere, over 370km). About 3/4 of the atmosphere above the earth is in the troposphere, and 97% is below the stratosphere. The outer edge of the stratosphere is the highest limit for an aircraft to fly with air support. Some high-altitude rockets can enter the middle layer. The lowest orbit of the satellite is in the thermocline, and its air density is 1% of the earth's surface. At the height of 16000km, air continues to exist, and even at the height of 10000km, there are still air particles. From a strictly scientific point of view, there is no clear boundary between airspace and outer space, but they are gradually integrated. The Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space pointed out that it is impossible to put forward accurate and lasting scientific standards to divide the boundary between outer space and airspace. In recent years, people tend to take the minimum height of artificial satellites from the ground (100 ~110) km as the lowest limit of outer space.

7. There are two kinds of little knowledge about the universe (not websites).

▲ The universe is infinite [just like the surface of the earth, it has a certain size (that is, it is limited), but it has no edges. The universe is also limited, but the gravity of the universe itself is so great that the space in the universe bends back to itself (just like a circle, only four-dimensional). ]

▲ There is no matter (including time, space and light) outside the universe, so there is no "thing".

But some scientists believe that there are other "universes" besides our universe.

▲ When a star whose mass is more than 0/00 times that of the sun/kloc runs out of fuel, its huge gravity will compress its volume to "0". The density of this point will be infinite, the gravity will be great, and even the space can be bent to attract light, electricity, signals and so on (this point is called a black hole).