6 Iodoquinoline

Sixth, what is the main use of light? My book "Heavenly Works and Objects" has a variety of features, such as lighting tools. In the dark night, it can break the dimness and make the eyes see things, which is of great benefit.
Ancient times, the light of today, people's fire is bright. In the room, when the night falls, I sit on the fire, or write, or communicate, the light is warm and soft, reflecting on the wall, the light and shadow are flickering, adding to the feeling.
It is also indispensable in the ceremony of sacrifice. Its flame is a symbol of light and gods, and people use it to worship gods and ancestors, showing their heart of respect. In the midst of the fire and the sparkling fire, the faith of the people is inherited.
Those who travel at night, holding a torch, can illuminate the road ahead and avoid it. Its light is limited, but in the long dark night, it is also a guide of hope, so as not to lose your way.
During travel, fire is also very useful. At night, you can use light to arrange things with text. In case of inconvenience, you can also use the light and shade of the fire, the quantity of the fire, and the specific information.
In other words, the use of light is used in life-like situations, or lighting, or sacrifice, or travel, or communication. In the past, it provided great help to people's lives, and it was indispensable.

6 - The light of the angle, its physical rationality is not like that. According to the "Heavenly Works", this light has the properties of refraction and inverse equivalence.
The light of the angle is refractive. Light enters another medium from one medium, and its line is deflected. If light enters the angle crystal from the air, because of the refractive index of the light, the light will change direction. This is because the light in different media has different propagation rates, resulting in easy direction. If the ancients used crystal light, the light will be tortuous, which is very wonderful.
It also has the property of reflection. When light encounters an angular surface, if the surface is smooth, according to the law of reflection, the angle of incidence is equal to the reflection angle. The ancient craftsmen used light with smooth corners and reflected light, which can be made into an image, or used in light and shadow.
Furthermore, the nature of dispersion also exists. The angle of chromatic light, due to the degree of refraction of different colors of light, is divided into chromatic light, which is like a rainbow. In the past, it was mysterious, but I did not know that it was caused by the dispersion of light. If sunlight enters the angle, it can be red, orange, orange, blue, blue, purple.
And light may have a total reflection at the angle. The light from the light-dense medium is emitted to the light-sparsing medium. The angle of incidence is greater than the angle of the boundary, and the light is fully reflected at the angle. This property is now mostly used in optical communication. The ancients did not know the reason, but occasionally they noticed that the light was left behind in the angle of the object. It is also a wonder.
Angular light, its refraction, reflection, dispersion, total reflection and other physical properties, the ancients did not understand its details, but they have already observed it, and it is the research path of today's people.

6-The fire of the flint is the light emitted by the flint. Its chemical properties actually have a certain stability.
The flint is mostly flint and the like, and its main component is silicon dioxide. When the flint strikes hard objects such as iron, due to the intense friction in an instant, the mechanical energy is converted into heat energy, causing the local temperature to rise sharply. At this time, the tiny particles on the surface of the flint are excited, generating high temperature and luminous light, which is the reason for the fire of the flint.
From a chemical point of view, the chemical properties of silicon dioxide itself are relatively stable. Under normal temperature and pressure, it is not easy to chemically react with common acids and bases. In the air, it is also difficult to react with gases such as oxygen and carbon dioxide. Even under the conditions of high temperature at the moment when the firelight is generated, although silica is heated, its chemical bond energy is strong and the structure is relatively stable. If there is no special chemical environment and reactants, its chemical composition is difficult to change significantly.
And the process of firing light from the flint phase is mainly dominated by physical changes, only involving the conversion of mechanical energy, heat energy and light energy, and chemical changes are not the main aspects. Therefore, in general, the chemical properties of the main substances involved in the firelight of cannon stones are quite stable. Unlike active metals, it is easy to react violently with other substances in ordinary environments. Therefore, in terms of chemical properties, the substances associated with the firelight of cannon stones have considerable stability and can maintain their own chemical properties under normal conditions.

6 - Stealing light from the wall was an act of reading when Kuangheng was young. Its method can also be learned from today, and many methods of integration can be discussed.
One of them is to borrow light from the outside. In ancient times, Kuangheng, the family was poor and had no candles, and the neighbor had candles but the light was not caught. He used to draw his light through the wall and read it with the light reflected by the book. Although there is no need to go through the wall today, he can make good use of natural light. During the day, if you are indoors, you can sit by the window and let the sun shine fully on the pages of the book. This is to borrow natural light. Moreover, when there is shade outdoors, such as under a big tree or in a pavilion, you can read by sunlight, which is both bright and natural. In addition, at night, you can borrow the light of street lamps. In the past, it was inconvenient for people to sleep. Today, there are many street lamps, which are as bright as day. Reading under street lamps can also be facilitated by light. If it is in a suitable place such as a park bench, it is also feasible.
Second, use lighting tools skillfully. Nowadays, there are many lighting appliances, which are comparable to a single candle. For example, a small and portable rechargeable desk lamp can be prepared, and its light can be adjusted to be strong and weak, which is convenient for use in different scenes. In the dormitory, if the roommate is already asleep, you can turn on the desk lamp and adjust the brightness to a suitable level, which is not disturbing, but also for yourself to read. Another example is a flashlight. In scenes such as camping, you can borrow its light to read. In addition, smart devices such as mobile phones also have lighting functions. Although the screen light is not the best reading light source, it can temporarily solve the dilemma of no light in an emergency, and many reading software can adjust the brightness and color temperature to make reading slightly more comfortable.
Third, create a shared bright space. In the past, there were no public libraries, study rooms and other places, but today it is very different. Libraries and study rooms have sufficient and suitable lighting, so that everyone can share the light and concentrate on learning. In the community, there are also various cultural activity centers, etc., to provide people with reading space, bright and bright, good atmosphere, can immerse people in the book, this is a collective good deed to create a bright environment, compared with the ancient antiquity of seeking light sources alone, more convenient and superior.

In today's city, the price of the light of the six songs has not been determined, but it can be roughly stated.
The light of the six songs in the city, the price involved may vary due to various factors such as texture, appearance, and origin. Ordinary texture, average quality, the price may be between tens of dollars and hundreds of dollars. If the texture is excellent, the production is skillful, and there are special sources or allusions, the price can climb to thousands of dollars or even higher.
All kinds of utensils in the market, where the quality is high and the price is good for everyone, the price must not be low. The light of the six songs, if the material is rare, the light color is warm, the carving is delicate, and the name of the craftsman is written, its price is not cheap, it can reach more than a thousand dollars, and it is for Fujia Yashi to buy.
On the contrary, if the material is ordinary, the craftsmanship is crude, it is only for daily use, and there is no unique feature, the price is mostly within a hundred dollars, for ordinary people to use.
There is no constant price in the city, and the price of the light of the six songs also rises and falls with changes in supply and demand and changes in the times. Merchants observe changes in time and sell at the right time; buyers judge the price of the goods and choose the good. In this way, the light of the six songs is in the market, and although its price is approximately in this range, it is actually flexible and changeable, and cannot be generalized.