The sun s light and heat emit itself, right?

That's right, the main thing is that the light nuclear fusion reaction inside it releases a lot of energy, which is manifested as electromagnetic wave radiation, and the visible light in many frequency bands is the sunlight you see, and the invisible light also carries a lot of energy, and the black body absorbs electromagnetic radiation and converts it into thermal radiation, which is heat.

Yes, send it yourself.

Yes, junior high school physics says nuclear fusion, but there will always be a day when it will dry up.

The statement that the sun's light and heat are emitted by itself is true.

The sun is a red-hot gas planet that shines on its own. The temperature on its surface is about 6,000 degrees Celsius, and the core temperature is as high as 15 million degrees Celsius. The radius of the Sun is about 696,000 kilometers, which is about 109 times the radius of the Earth.

Its mass is tons, which is about 332,000 times that of the Earth.

The average density of the Sun is grams per cubic centimeter, which is about 1 4 of the density of the Earth. The average distance between the Sun and our Earth is about 100 million kilometers. The structure of the sun from the inside out is mainly divided into:

The center is the thermonuclear reaction zone, and beyond the core is the radiation layer, which is the troposphere, and beyond the troposphere is the solar atmosphere.

According to the theory of nuclear physics, the center of the sun is a thermonuclear reaction zone. The central region of the Sun occupies 1 4 of the entire radius of the Sun and is more than half of the mass of the entire Sun. This indicates that the density of matter in the central region of the Sun is very high.

Up to 160 grams per cubic centimeter. Under the attraction of the sun's own strong gravity, the central region of the sun is in a state of high density, high temperature and high pressure.

It is the birthplace of the sun's immense energy. The energy generated in the central region of the Sun is mainly transmitted in the form of radiation. Beyond the central region of the sun is the radiant layer, which extends from the radius of the sun at the top of the thermonuclear center to the radius of the sun, where the temperature, density, and pressure decrease from the inside out.

In terms of volume, the radiant layer accounts for the vast majority of the total volume of the Sun. Through thermonuclear fusion, the sun emits light by burning large amounts of hydrogen concentrated at its core, consuming an average of 6 million tons of hydrogen per second. After another 5 billion years, the Sun will deplete its hydrogen reserves, and then the nuclear region will shrink and the nuclear reaction will expand to the outside, when its temperature can reach more than 100 million degrees, leading to helium fusion.

That's right, under high pressure and high temperature, the sun is undergoing fusion reactions from the inside to the surface, and it is precisely because these fusion reactions release a lot of energy, so that the sun has continuously emitted light and heat for hundreds of millions of years.

With the continuous development of society, our living standards are getting higher and higher, and we have a lot of time to increase our knowledge. In the past, the conditions were not very good, there were many brothers and sisters in the family, and everyone's education level was generally not high, and more time was spent helping their parents with work. But now, because of reform and opening up, life has made a qualitative leap.

Everyone also attaches more and more importance to education, and understands that children's education should be grasped from an early age, otherwise it may be relatively late when the child grows up and then let him study hard. <>

In general, we are exposed to physics in the second year of junior high school, which attaches great importance to logic and is based on mathematics, and physics can solve many problems in our lives, so it is very necessary to learn physics well. Just imagine, knowledge is often in life, physics is a good embodiment, if the difficulties encountered in life, we through the physics knowledge we have learned successfully solved, then we will have a sense of achievement, at the same time will greatly stimulate our interest in learning.

In physics, the sun emits light and heat, but sunlight is not a light source. We need to understand what the definition of a light source is, in nature, some objects are emitting, some are not, we call the object that can emit light on its own and is emitting light. There are two types of light sources, one is a natural light source, such as the sun as we know it, and the other is an artificial light source, such as a burning candle, an electric light that is turned on, and so on.

However, such as the moon and boiled noodles, they mainly rely on the reflection of foreign light to make us discover it, and such reflectors cannot be called light sources. <>

Sunlight is a pathway of generation, which is simply the electromagnetic radiation of all spectrums of the sun. On Earth, sunlight from the sun is filtered by the atmosphere and hits the earth's surface. Sunlight is composed of ultraviolet rays, visible light, and infrared rays, so we can't be exposed to sunlight for a long time, and the ultraviolet rays inside will harm our ** and accelerate our **aging.

Books are the ladder of human progress, physics is the best in life, and it can also solve problems in life. We must learn to analyze specific problems, and only in this way can we really learn physics well!

Because the definition of the light source is the feeling of luminescence brought about by the luminous object after irradiation or direct irradiation, and the sun belongs to its own heating, luminescence, not caused by the irradiation of other objects, and if the sun belongs to the light source, the sun contains a large amount of ultraviolet rays, which will cause very serious damage to the human body.

This is because the sun is a light source, but sunlight is not a light source.

I think it's a natural phenomenon, and it's also based on science, so we have to look at it rationally.

The thermonuclear reaction of the sun is the process of hydrogen milling and nuclear fusion into helium nuclei, and there are two possible reaction sequences: one is the proton cycle and the other is the carbon-nitrogen cycle

In thermonuclear reactions inside the Sun, about 600 million tons of hydrogen can be turned into helium per second, losing more than 4 million tons of mass and releasing 3 8 1026 joules The sun has been burning for nearly 5 billion years.

Under high pressure and high temperature, fusion reactions are taking place from the inside to the surface of the sun, and it is precisely because these fusion reactions release a large amount of energy that makes the sun continuously emit light and heat for hundreds of millions of years.

The sun glows, heats up, and is a big fireball. What method of explanation was used - analogy to explain the method.

For example, the method of using the similarities between two different things to compare them to highlight the shape characteristics of the thing and enhance the vividness and vividness of the explanation is called analogy.

The method of illustration of analogy in the expository text is consistent with the metaphor and association in the figure of speech. The difference is that figurative rhetoric has similes, metaphors, and borrowings, while illustrations use similes and metaphors, while borrowings are not appropriate.

The sun shines, heats up, and is a big fireball", comparing the "sun" to a "big fireball" is an analogy.

Hello, I'm glad to answer for you the first time! If you have any questions, please ask in time, if you are satisfied!

If the sun stops heating up, then our earth will be a very bleak scene, and mankind will eventually perish. 1. The sun. From a long, long time ago, we humans also had a certain understanding of the sun, believing that it was a light that illuminated our world, and there was also a legend that the sun was turned into a golden crow, and at that time there was a story of Hou Yi shooting the sun, but it also reserved the last ray of sunlight for mankind.

In that era, without the support of science and technology, they could only imagine out of thin air, but with the development of society and the progress of science, we have more and more explorations of the universe and a more and more thorough understanding of everything in the world. In fact, the sun is a planet outside the universe, which is very far away from our earth, but it is so closely connected. Each of its rays of light falls on every tree and grass on the earth, providing us with warmth and energy.

2. Destruction. If the sun stops digging its light and heat, then human beings are bound to perish, because on our earth, all animals and plants need sunlight to obtain energy, especially for plants, they need to use photosynthesis for energy conversion, so that energy transfer occurs.

At the same time, without its light and heat, our earth will be dark, the temperature of the environment we are in will drop sharply, and eventually all animals and plants may go extinct, and human beings are no exception, even with strong scientific support, then it will not be able to maintain our survival. Once there is no sun, there will be no warmth in the world, we may not be able to adapt to this environment, and in the end, only death awaits us. The earth will eventually become a cold balloon of water, without a trace of life.

The forces of nature are infinite, they provide energy for our survival, explore the mysteries of the universe, and may also give us answers in the future.

The sun emits the light and heat necessary for us to touch human beings and is produced by ().

a.Nuclear fusion reactions.

b.Nuclear fission reactions.

c.Hydrogen combustion.

This is the answer to the question: a

No. The sun is a large sphere, and its light radiates in all directions.

The Sun is a star, the central body of the solar system, and a source of light. It is divided into nuclear reaction zone, convection zone, radiation zone and atmosphere. The surface layer of the Sun is customarily called the atmosphere of the Sun, and from the inside out, it can be divided into the photosphere, chromosphere, and corona.

The photosphere is an extremely thin layer on the surface of the sun, and the diameter of the sun is determined according to this circular surface.

The chromosphere is the middle layer of the solar atmosphere, its temperature is much higher than that of the photosphere, but its light is only one hundred-thousandth of the light emitted by the chromosphere, we usually cannot see it directly, only when a total solar eclipse occurs or with a chromosphere telescope, we can see a layer of rose-colored chromosphere.

The corona is the outermost layer of the Sun's atmosphere. In years when solar activity is intense, the corona is round, and in years when solar activity is weak, the corona is oblong, its density is thin and thin, we usually can't see it with the naked eye, and only when a total solar eclipse occurs, can we see a silvery-white coronal layer.

The Sun is about 100 million kilometers away from the Earth, so when we look at the Sun, we don't think it's big, especially at noon, when the Sun is surrounded by an empty atmosphere, so it looks smaller. But it's actually huge, and it would take 1.3 million Earths to be worth one sun. It takes 365 days, 5 hours, 48 minutes and 46 seconds for the Earth to revolve around the Sun, at which point the Earth actually rotates 366 times.

We usually set 365 days as a year, called a common year, but after this regulation, there are 5 hours, 48 minutes and 46 seconds less, and every 4 years there is a decrease of 23 hours, 15 minutes and 4 seconds, close to the time of one day, we add this day to the shortest February, so that there are 366 days in a year, called a leap year. But if there is a leap every four years, it is a little longer than the time for the earth to revolve around the sun, so we stipulate that a year with two zeros at the end is a leap year only a multiple of 400, for example, 2000 is a leap year, and 2100 is a common year. That is, there is no leap in 100 years, and there is a leap in 400 years.

No, the sun's light and heat are distributed to all parts of the solar system, and the earth receives only a small part of it.

You can model the sphere, the distance between the sun and the earth d, the sphere 4 d, and then calculate the illuminated area (cross-sectional area) of the earth and distribute the radiation proportionally.