The universe is a unity of space, time, matter, and energy. It's all space and

The sum of time. The universe as it is generally understood refers to a continuous system of space-time in which we exist, including it

all matter, energy, and events. The overall explanation of this system constitutes cosmology.

For several centuries, scientists have established a theory about the universe based on modern physics and astronomy

A modern scientific theory called physical cosmology.

According to the theory of relativity, information travels at a limited rate, so in some cases, such as in occurrence

In the case of the expansion of the universe, we will only receive a small fraction of the area very far away from us

The information of the region, the information of other parts will never be able to reach our area. can be us

The observed part of space-time is called the "observable universe", "visible universe", or "our universe". It should be strong

Interestingly, this is due to the structure of space-time itself, and has nothing to do with the observation equipment we use

System.

The universe is made up of about 4% ordinary matter, 23% dark matter, and 73% dark energy.

universe

universe

Chinese name: universe

Foreign name: universe

Current age: about 13.82 billion years

Current depth: 124 billion light-years

Cognitive processes

Historical materials of China

"Wenzi Nature": In ancient times, it was called the universe, and the four directions were called the universe. "Corpse": "Up."

The lower four directions are said to be the universe, and the past is said to be the present. Under this concept, "Yu" represents the upper and lower four directions, that is, the place

There is space, "Zhou" represents the past and present, that is, all time, "Yu": infinite space, "Zhou": nothing

For a limited time. So the word "universe" has the meaning of "all time and space". Put the concept of "universe".

It is linked to time and space, and embodies the unique wisdom of the ancient people of our country.

The use of the word "universe" was first used in the book "Zhuangzi", and at the same time, the book "Zhuangzi" was also used

Giving a more abstract definition of the universe, he said: "Out of the root, into the know." There is substance but nowhere to be found,

There is a long and no plagiarism. Those who have something but no knowledge have the truth. There is a real but nowhere to be done, Yu also; There is a long and

Those who have no original plagiarism, too. Modern scholar Zhang Jinghua translates it as: "There is a physical existence but it is not fixed and static."

It is called Yu that does not change in a certain position; There are extrinsic attributes, but there is no fixed measure to measure them

Eon. This definition of the universe has nothing to do with time and space, and has similarities with modern cosmology. But it has not been used for a long time

We are well acquainted.

Numerous points of view

In ancient times, people's understanding of the structure of the universe was in a very naïve state

Make assumptions about the structure of the universe based on your own living environment. During the Western Zhou Dynasty in China, he lived in China

The early theory of covering the heavens put forward by the people of the earth believed that the heavenly dome was like a pot, upside down on the flat earth

Above; Later, it developed into the later Gaitian theory, which believed that the shape of the earth was also arched. 7th BC

The Babylonians believed that both the heavens and the earth were arched, and that the earth was surrounded by the sea, while its center was

It's a high mountain. The ancient Egyptians imagined the universe as a big box with the sky as the lid and the earth as the bottom

In the center is the Nile. The ancient Indians imagined a disc-shaped earth burdened by several elephants, and the elephants were

Standing on the back of a huge turtle, at the end of the 7th century BC, Thales of ancient Greece believed that the earth was floating in water

A huge disc on the face, shrouded in an arched celestial dome. There are also those who believe that the earth is just one

A piece of the deck on the turtle, and the turtle is standing on the tortoise tower one after another, and it was the ancient Greeks who first realized that the earth was spherical. In the 6th century BC, Pythagoras from

From the perspective of aesthetics, it is believed that the most beautiful of all three-dimensional figures is the spherical shape, and advocates the celestial bodies and the places we inhabit

The earth where they live is spherical. This concept was inherited by many later ancient Greek scholars, but until

In 1519~1522, after the first circumnavigation of the world led by F. Magellan of Portugal,

It was only then that the idea that the Earth was spherical was finally confirmed.

Geocentrism, heliocentrism, and the law of gravitation

In the 2nd century AD, C. Ptolemy proposed a complete geocentric theory. This doctrine considers the earth

In the center of the universe, the moon, the sun, and the planets, as well as the outermost stars, the heavens, are all present

Rotates around the earth at different speeds. To illustrate the unevenness of planetary motion, he also believed that the planets were

The wheel revolves around its center, and the center of the wheel revolves around the earth along the wheel. Geocentrism was once in Europe

It has been passed down for more than 1,000 years. In 1543, N. Copernicus proposed the scientific heliocentric theory, which believed that the sun was located in the universe

The center of the universe, and the Earth is an ordinary planet that orbits the Sun in a circular orbit. By the 16th century Goba

It was only after the establishment of the heliocentric theory that it was generally recognized that the earth is one of the planets that revolves around the sun, including the earth

The eight planets, including the sphere, form a planetary system that revolves around the Sun – the main components of the solar system

Member. In 1609, J. Kepler revealed that the earth and the planets orbit the sun in an elliptical orbit

Copernicus's heliocentric theory was exhibited, and in the same year, Galileo Galilei was the first to use a telescope to observe the sky

A large number of observations confirm the correctness of the heliocentric theory. In 1687, I. Newton proposed the gravitational determinator

The law profoundly reveals the planets orbiting the ether

Saturn in its natural colors

Saturn in its natural colors

The mechanical causes of yang motion give heliocentrism a solid mechanical foundation. After that, people gradually

A scientific concept of the solar system was established.

There is more to the universe than just the Milky Way

In Copernicus's image of the universe, the star is just a point of light in the sky of the outermost star. 1584

In the year, Giordano Bruno boldly canceled this layer of stellar heaven, believing that the stars were all distant suns.

In the first half of the 18th century, due to the development of E. Halley on the stars on their own and J. Bradley on the stars at a great distance

Bruno's speculation is increasingly agreed. In the middle of the 18th century, T. Lai

T. I. Kant and J. H. Lambert speculated that the stars and the Milky Way that spread throughout the day constituted a huge sky

body system. Friedrich Wilhelm Herschel pioneered the method of sampling statistics, using a telescope to count

The number of stars in a large number of selected areas of the sky and the ratio of bright to dark stars were first acquired in 1785

A flat, flattened, unevenly contoured, sun-centered diagram of the structure of the Milky Way, thus establishing the concept of the Milky Way

The foundation. Over the next century and a half, H. Shapley discovered that the Sun was not at the center of the Milky Way.

J.H. Oult discovered the rotation and spiral arms of the Milky Way, as well as many people's understanding of the diameter and thickness of the Milky Way

Determination, the scientific concept of the Milky Way was finally established.

sun

sun

In the middle of the 18th century, Kant and others also proposed that in the entire universe, there are countless people like us

A celestial system like the Milky Way. At that time, it was likely that the "nebula" that looked like a mist was likely

It is such a celestial system. After that, it was a tortuous 170-year journey of exploration until 1924

It was only by E.P. Hubble that the Transgalactic Galaxies were confirmed by E.P. Hubble using the Cepheid parallax method to measure the distance of the Andromeda Nebula and so on

exists.

Extragalactic galaxies are getting farther and farther away from us

In the past half century, through the study of extragalactic galaxies, people have not only discovered galaxy clusters, super

galaxy clusters and other higher-level celestial systems, and have expanded our horizons to about 14 billion

Light-years deep in the universe.

model

Theoretical basis

In 1911, E. Herzplon created the first color magnitude map of the Milky Way star cluster, and in 1913,

Bertrand Arthur William Russell drew a spectrophotometric diagram of a star, known as the Herault diagram. Russell is in the hunt

After obtaining this diagram, it is proposed that a star starts from the red giant, shrinks first into the main sequence, and then along the main sequence

slippery and eventually became the stellar evolution of the red dwarf. In 1924, Arthur Stanley Eddington proposed

the mass-light relationship of stars; In 1937~1939, C.F. Weizsäcker and Bate revealed the energy of stars

The source comes from the nuclear reaction of hydrogen fusion into helium. These two discoveries led to Russell

Galaxy

Galaxy

The theory was denied and led to the birth of the scientific theory of stellar evolution. For the study of the origin of galaxies

It started late, and it evolved from protogalaxies in the late stages when our universe began to form.

In 1917, A. Albert Einstein used his newly founded theory of general relativity to establish a "static

state, finite, and unbounded" model of the universe laid the foundation of modern cosmology. In 1922, G.D. Ferdin

Lidman discovered that, according to Albert Einstein's field equations, the universe is not necessarily static, it

It can be either inflated or oscillating. The former corresponds to the open universe and the latter to the closed

The universe of unity. In 1927, G. Lemait also proposed a model of an expanding universe, and in 1929 Hubble made the discovery

The redshift of a galaxy is proportional to its distance, establishing the famous Hubble's law. This discovery is a reversal of the puff

Strong support for the expansion of the universe model. In the middle of the 20th century, G. Gamov and others proposed the Hot Big Bang universe

Model. The discovery of microwave background radiation in 1965 confirmed the predictions of Gamow et al. Since then, many

The Big Bang model of the universe is regarded as a standard model of the universe. In 1980, the American Guss exploded in heat

On the basis of the cosmic model, the pre-Big Bang exploding cosmic model is further proposed.

A picture of the starry sky

The results of contemporary astronomical research show that the universe is hierarchical, cloth-like, and no

A celestial system that expands, has a variety of material forms, and is constantly moving and developing.

Hierarchical planets are the most basic celestial systems. There are eight planets in the solar system: Mercury Gold

Planets: Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Except for Mercury and Venus, other lines

Spider Nebula

Spider Nebula

Stars have satellites orbiting it, the Earth has a moon Moon, Saturn has the most satellites that have been confirmed

There are 28 of them. The planets, asteroids, comets, and meteoroids both orbit around the central celestial body, the Sun, which makes up the Sun

System. The Sun accounts for 99.86% of the total mass of the solar system, and its diameter is about 1.4 million kilometers, making it the largest planetary wood

The diameter of the star is about 140,000 kilometers. The size of the solar system is about 12 billion kilometers (bounded by Pluto). Yes

Evidence suggests that there are other planetary systems outside the solar system as well. 250 billion sun-like stars and stars

The Milky Way is a much larger celestial system. Most of the stars and interstellar objects in the Milky Way

The mass is concentrated in an oblate spherical space, which looks like a "discus" from the side and spirals from the front

Vortex. The Milky Way is about 100,000 light-years in diameter, and the Sun is located in one of the spiral arms of the Milky Way, at a distance from the galactic center

About 30,000 light years. There are many similar celestial systems outside the Milky Way, called extragalactic galaxies, often referred to simply as stars

System. About 1 billion have been observed. Galaxies are also clustered into large and small groups, called galaxies

Regiment. On average, each galaxy cluster has about 100 galaxies with a diameter of tens of millions of light-years. It has been issued

There are tens of thousands of galaxy clusters. A small cluster of about 40 galaxies, including the Milky Way, is called the Honka

Phyletic groups. Several clusters of galaxies come together to form a larger, higher-level celestial system called a supergalaxy

Regiment. Superclusters tend to have an elongated shape, with diameters of hundreds of millions of light-years. Usually superclusters

It contains only a few galaxy clusters, and only a few superclusters have dozens of galaxy clusters. The sum of the local group of galaxies

The supercluster of about 50 galaxy clusters in its vicinity is called the local supercluster.

Magellan Nebula Amp; amp

Magellan Nebula Amp; amp

Cosmic History

Cosmic History

According to media reports, CNN's Science Space Channel was selected in 2012

Take some of the most spectacular photos of planets, moons, galaxies, and nebulae in the cosmic sky

including the Orion Nebula, Saturn's mysterious and beautiful ring structure, and the Earth's north

Beautiful auroras in the polar regions or sandstorms on Mars, etc. Orion nebula map shown here

The image, taken by the Atacama Explorer Experimental Telescope at submillimeter wavelengths, shows this constant

New stars are forming in the star-forming regions.

Origin and Ending

The constant expansion of the universe

It is believed that the universe was created 14 billion years ago in a big bang. 3 billion years after the Big Bang,

The first ripples of matter appear. 2 billion ~ 3 billion years after the Big Bang, quasars gradually formed. The Big Bang

Nine billion years later, the sun was born. Life on Earth began to evolve 3.8 billion years ago.

The material emitted by the Big Bang travels through space, such as the massive galaxies made up of many stars

Made of these substances, our sun is one of these countless stars. Originally, people imagined

The universe will stop expanding due to gravity, but scientists have discovered that there is a "dark energy" in the universe

It creates a repulsive force that accelerates the expansion of the universe.

The process of expansion after the Big Bang is a battle between gravity and repulsion, and the power generated by the explosion is one

repulsion, which keeps the celestial bodies in the universe moving away; There is a gravitational attraction between the celestial bodies, which will block the heavens

bodies away from each other, even trying to bring them closer to each other. The magnitude of gravitational pull is related to the mass of the celestial body and is therefore large

Will the universe eventually expand after the explosion, or will it eventually stop expanding and shrink in reverse?

small, it all depends on the density of matter in the universe.

Theoretically, there is some kind of critical density. If the average density of matter in the universe is less than the critical density

degree, the universe will continue to expand, called "opening the universe"; If the average density of the substance is greater than the critical one

Sooner or later, the process of density, expansion will stop, and with it, contraction, which is called "closed universe".

The problem seems simple, but it's not. The theoretically calculated critical density is 5×8^-30 g/cm3. But it is not so easy to determine the average density of matter in the universe. Intergalactic

In the vast intergalactic space, the average density is only 2×10^-31 g/cm3, which is much lower than above

Critical density.

However, there is all kinds of evidence that there is still so-called dark matter in the universe that has not yet been observed.

The amount of the material may be much greater than that of the visible substance, which creates a great deal of uncertainty in the determination of the average density

Plain. Therefore, whether the average density of the universe is really less than the critical density is still a controversial question

Title. However, for now, it is more likely to open the universe, because there are more in the universe

Dark energy.

When stars reach an advanced stage of evolution, they throw some matter (gas) into the stars