Speeches on the mysteries of the solar system

The solar system was formed 4.6 billion years ago with the formation of the sun. The solar nebula gradually condensed due to its own gravitational pull, and gradually formed a celestial system composed of multiple celestial bodies arranged according to certain rules. The members of the solar system include one star, nine planets, at least sixty-three moons, about a million asteroids, countless comets and interstellar matter, among others.

The Sun is an ordinary star in the Milky Way. According to the theory of stellar evolution, the Sun, like most other stars, was born from a cloud of interstellar gas. This gas cloud existed about 4.6 billion years ago in the disk-like structure of the Milky Way, about 2.5 billion kilometers from its center.

It was about 5 million times the size of the current sun, and its main component was hydrogen molecules. This is the "Solar Nebula". After more than 400,000 years of contraction and condensation, a star was born in the center of the nebula, which is the sun.

Shortly after the formation of the Sun, some of the gas and dust that remained around the Sun formed planets orbiting the Sun and many other solar system bodies such as asteroids and comets, including the Earth and the Moon.

Diagram of the positions of the nine planets of the solar system and the Sun. From left to right are the Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.

The sun is nothing special in the vastness of the universe. There are about 200 billion stars that make up the Milky Way, and the Sun is only one of them. The Sun is five billion years old and is in the middle of its life.

As the center of the solar system, all living things on Earth need the light and heat it provides, directly or indirectly, for their growth. The temperature of the sun's inner core is 15 million degrees Celsius, where hydrogen-helium fusion reactions take place. Nuclear fusion reactions consume about five million tons of matter per second and convert them into energy that is released in the form of photons.

It takes more than a million years for these photons to reach the surface of the sun from the center of the sun. After the photon travels from the center of the sun, it passes through the radiation belt, losing energy in collisions with atomic particles along the way. It then passes through the convection zone, where the photon's energy is absorbed by the hot gas, which transfers energy to the surface in the convection current.

By the time they reached the edge of the convection zone, the photons had cooled to 5,500 degrees Celsius. What we can see directly is the photosphere on the surface of the Sun. The photosphere is relatively active, with a temperature of about 6,000 degrees Celsius, which belongs to the "cooler" part.

There are undulating convection units called "grains of rice" in the photosphere. Each grain of rice is about 1,600 kilometers in diameter, and they are the culmination of the thermals that rise from the inside of the sun. It is in the constant convection activity that the sun releases the equivalent of 100 billion megaton nuclear bombs into space every second.

About five billion years ago, an interstellar dust cloud called the "primordial solar nebula" began to collapse in gravity. As the volume shrinks, the temperature of the core increases, and the density increases. When it shrinks by a million times and becomes a primordial star, the temperature in the core region also rises to about 10 million degrees Celsius.

When the temperature of the core region of this primordial star or fetal star is 10 million degrees higher, the hydrogen fusion reaction is triggered, which is the reaction of the hydrogen bomb**. At this time, a star called the Sun was born.

Depending on what object you are, the surface temperature of the sun is about 6000 degrees Celsius, and the farther away from the sun, of course, the lower the temperature, just look at what the melting point of the substance you are talking about.

To put it simply, it was formed by the collision of nebulae.

The Earth, like the other eight planets in the solar system, orbits the sun at the same time. It rotates around an imaginary axis of rotation, which is the rotation of the Earth.

Hundreds of years ago, people proposed.

There are many ways to prove the rotation of the earth, and the famous "Foucault pendulum" allows us to really see the rotation of the earth, but why does the earth rotate around its axis? Why does it revolve around the sun? This is a science that has been making for many years.

Roughly speaking, rotation is a basic form of motion of the celestial bodies in the universe, but in order to truly answer this question, it is necessary to first understand how the sphere and the solar system are formed. Earth's rotation and me.

The generation of rotation is closely related to the formation of the solar system.

Modern astronomical theories suggest that the solar system was formed by the so-called primordial nebula, a large very thin cloud of gas that was disturbed in some way 5 billion years ago.

Kinetic influence, contraction towards the center under the action of gravity. After a long period of evolution, the density of the matter in the center became higher and higher, and the temperature became higher and higher, and finally reached the point where it could trigger a thermonuclear reaction.

Yang. The residual gases around the sun gradually form a rotating disc-shaped gas layer, which gradually gathers into solid particles, microplanets, primitive planets, and finally forms in the gas layer through the processes of contraction, collision, trapping, and accumulation.

into independent asteroids and asteroids and other solar system celestial bodies.

We know that to measure the speed of an object moving in a straight line, it can be expressed in terms of velocity, so what is the measurement of the rotation of the object?

This? One way to do this is to use "angular momentum".For an object revolving around a fixed point, its angular momentum is equal to the mass multiplied by the velocity, multiplied by the distance of the object from the fixed point. There is a very important angular momentum guard in physics.

The law of constancy, it is said, is that a rotating animal body. If it is not acted upon by an external moment, its angular momentum does not change due to the change in the shape of the object. For example, a ballet dancer suddenly tucked his arms in the middle of a spin.

When the distance between the center of mass and the fixed point becomes smaller), his rotation speed will increase, because only in this way can the angular momentum be kept constant. This law plays an important role in the generation of the Earth's rotation speed.

Formation of the sun. The primordial nebula of the system originally had angular momentum, and after the formation of the solar and planetary systems, its angular momentum was not lost, but it was inevitably redistributed, and the stars were separated from the primordial nebula in the long process of accumulating matter.

A certain angular momentum is obtained. Since angular momentum is conserved, the planets will also rotate faster and faster during contraction. The Earth is no exception, and the angular momentum it obtains is mainly distributed between the Earth's revolution around the Sun, and the Earth-Moon system reciprocates.

This is the origin of the Earth's rotation in orbit and the rotation of the Earth, but to truly analyze the orbital motion and rotation motion of the Earth and other major planets, scientists need to do a lot of research work.

That is to say, in the formation of the Earth, motion, especially rotation, accompanied the formation of the Earth from beginning to end, rather than the beginning of its rotation or revolution for some reason after the formation of the Earth.

The definition of the universe is space and matter outside the Earth's atmosphere. In the universe, the Earth is the only planet known to mankind that has life.

Creation of the Universe:

In the beginning, matter could only exist in the form of elementary particles such as neutrons, protons, electrons, photons, and neutrinos. The continuous expansion of the universe after that caused the temperature and density to drop very quickly. As the temperature decreases and cools, atoms, nuclei, and molecules are gradually formed, and they are compounded into the usual gas.

The gas gradually coalesced into nebulae, which further formed a variety of stars and galaxies that eventually formed the universe we see today.

Constant expansion: Dark energy accounts for 74% of all matter in the universe, and it is the driving force behind the accelerated expansion of the universe. The expansion process of the universe is in the balance of two opposing forces, just like yin and yang. One of these forces is gravity, which slows down the expansion, and another powerful counterforce is dark energy, which accelerates the expansion of the universe.

And now, it seems, dark energy wins. The visible matter in the universe is far from enough to unite the universe, and if it were not for the existence of a mysterious and invisible matter, galaxies would have fallen apart long ago. Scientists call this unseen, mysterious substance "dark matter."

Accelerating expansion: Researchers have calculated that the current rate of expansion of the universe, known as the Hubble constant, is about kilometers (seconds, millions of parsecs). Each million-second difference is equivalent to 3.26 million light-years, so for every million parsecs that a galaxy is farther away from Earth, its speed away from Earth increases by kilometers per second. This means that in 9.8 billion years, the distance between cosmic objects will double.

The end of the universe:

The laws of thermodynamics do not allow the universe to gain immortality, and when new stars cannot continue to form, the universe reaches the equilibrium point of heat death, and the state of the universe is like the bowl of soup at the beginning of its birth. Heat death is the thermodynamic end, and the temperature of any part of the universe is just above absolute zero, meaning that nothing will survive. A small number of scientists believe that if the universe ends up in a big collapse, all matter will eventually become atomic, and then after an accidental quantum fluctuation, a new round of big ** will be formed, and the next universe will be born.

The universe is the general term for all things in heaven and earth. The word universe first appeared in the book "Corpse" in the corpse school of the Warring States period. The corpse leader thinks:

The upper and lower four directions are said to be the universe, and the past and present are called the universe. In this way, we can know that "universe" means space and "universe" means time. The concepts of space and time have evolved over time.

The boundaries of the universe have gradually expanded with the progress of astronomy.

The universe is made up of dark matter. Dark energy. Fixed star.

Satellite. Black holes and other components, the universe originated 13.7 billion years ago and was born, and the universe was just an extremely dense one at the beginning. The tiny dot finally becomes the universe, whether the universe is finite or infinite, no one knows so far, and the universe that satisfies the cosmological principle (uniform isotropy in three-dimensional space) is certainly boundless.

However, whether it is limited or not should be discussed in three cases.

If the curvature of three-dimensional space is positive, then the universe will be finite and boundless. However, it is different from Einstein's finite and boundless static universe, which is dynamic, will change with time, constantly pulsate, and cannot be stationary. This universe begins with an infinitely small singularity in space**, expanding.

The material density of this singularity is infinitely high, the temperature is infinitely high, the curvature of space is infinite, and the curvature of space-time in four dimensions is also infinite. During the expansion process, the temperature of the universe gradually decreases, and the density of matter, the curvature of space, and the curvature of space-time all gradually decrease. Once the volume expands to a maximum, it turns into contraction.

In the process of shrinkage, the temperature rises again, the density of matter, the curvature of space and the curvature of space-time gradually increase, and finally reaches a new singularity.

Have you ever heard of the mysteries of the universe? There are 400.1 trillion planets in the universe, such as Jupiter, Mars, and Venus, and scientists estimate that there may be no less than 3.2 billion stars in the Milky Way, the solar system is the center and a collection of all celestial bodies that feel the gravitational constraint of the sun, including eight planets, as well as at least 173 known moons, five identified dwarf planets and hundreds of millions of small celestial bodies in the solar system.

In the vast universe, the Milky Way, the solar system, asteroids, etc. are just tiny particles in the universe. We have a pair of eyes to discover beauty, to explore, to seek, and to obtain beauty in it that we have never had before. Isn't it good to make our unknown world more and more beautiful, you say?

It is recommended that you write about the formation process of each star in the solar system, starting with the nebula, then the matter begins to gather, the internal fusion occurs, the initial solar system is formed, the planets are formed, and the solar system is cooled.

Search the Internet for the universe in Hawking's husk.

In the past, there was a book called "The Solar System". From the sun, planets, and moons to asteroids, dust, etc.

Now, go to the book city and look for it, there are a lot of them.

Mathematical Principles of Natural Philosophy.

Your question is so abstract, no one dictates what the 10 mysteries are, it can only be the 10 that the author of a book or a TV show lists in his opinion.

1。Cosmic Great** (Origin of the Universe).

2。Black hole. 3。Time.

4。High-dimensional space.

5。The origin of life.

6。What is consciousness.

7。Extraterrestrial beings (extraterrestrial intelligent beings).

8。The unification of the four fundamental forces.

9。The uncertainty principle of quantum mechanics.

10。Antimatter.

11。Wormholes and time travel.

12。String Theory.

13。Artificial intelligence.

14。The end of the universe.

Wait a minute... These can all be included in the list of candidates for the mysteries of the modern universe.

Agree with the answer of the first floor, there are many mysteries in the universe, the earth is the most suitable planet for life in the solar system, which itself is also very mysterious, how did the cosmic explosion make the earth so accurately meet the requirements of the cradle of life. Therefore, we should discover that the mysteries of the universe are actually very close to our own lives, and understand these problems scientifically.

The universe is the general term for all things in heaven and earth.

The word universe first appeared in the book "Corpse" in the corpse school of the Warring States period. The corpse leader thinks: "The upper and lower squares are called the universe, and the past and the present are called the universe."

In this way, we can know that "universe" means space and "universe" means time. The concepts of space and time have evolved over time. The boundaries of the universe have gradually expanded with the progress of astronomy.

Our ancestors were limited by conditions to observe everything on the earth with their eyes, so they mistakenly believed that the universe had boundaries, so people often said that "it is near in front of us, but far away in the sky". Although our ancestors' understanding of the boundaries of the universe is biased, it is worth acknowledging that they skillfully combined time and space more than 2,300 years ago. Before the Middle Ages, Europe was still separated from space.

When it comes to the idea of the universe, our ancestors were much richer than Westerners at that time.

With the development of science and technology, observation tools are becoming more and more advanced, and people's understanding of the universe has gradually deepened, from the sun to the solar system, and then extended to the Milky Way, extragalactic galaxies, galaxy clusters, and total galaxies. More than 20 billion light-years of deep space can now be observed, and this range contains more than 1 billion galaxies. The "physical universe" is the universe that is explained in terms of physical phenomena.

It is boundless in space and has no beginning or end in time, and is partly visible to people, that is, the "observed universe", and most of it is beyond the reach of people's observations.

The universe is divided into a condensed structure universe and a dissipative structure universe, the universe with a condensed structure is an inanimate universe, and the universe at that time was a huge black hole, and all the material energy contracted to the core of the universe, slowly condensing into a huge material energy mass. At this time, the speed at which matter (mass) in the universe is converted into energy is much smaller than the speed at which energy is converted into matter, so the universe condenses into a supergiant mass of matter and energy. This state of the universe can not be maintained for a long time, when the universe shrinks to a certain extent, due to the increase in temperature and pressure inside, the speed of the transformation of matter into energy slowly becomes faster, and the speed of energy into matter slowly slows down, when this change reaches a critical point, the whole universe will be reversed, and gradually the speed of matter into energy is far greater than the speed of energy, the whole universe begins to surge sharply, and after reaching a certain extent, the universe will be big ** , so the universe began to release and radiate energy, which is the beginning of the dissipative universe, and the dissipative universe is the living universe.

Therefore, the universe is scattered and born, and gathered is dead;And life is life when it gathers, and death when it is scattered. The universe and life are so dialectically united.

Within the 40 trillion kilometers around the Earth, there is no second planet for human beings.