About the question of light, about the question of light?

It's not good! Ultraviolet rays make fluorescent substances glow, which has a certain bactericidal effect.

Infrared rays also have a bactericidal effect, and people occasionally get sunburned, and they will get ** cancer if they get too much sun.

Benefits: The most important effect of infrared rays.

The basis of the action of infrared** is the thermal effect. Under infrared irradiation, tissue temperature increases, capillaries dilate, blood flow accelerates, substance metabolism is enhanced, and tissue cell viability and regeneration ability are improved. Infrared** in chronic inflammation, improve blood circulation, increase the phagocytic function of cells, eliminate swelling, and promote the dissipation of inflammation.

Infrared rays can reduce the excitability of the nervous system, and have the effect of analgesia, relieving striated and smooth muscle spasms, and promoting neurological recovery. In **slow** infected wounds and chronic ulcers, improve tissue nutrition, eliminate granulation edema, promote granulation growth, and speed up wound healing. Infrared irradiation has the effect of reducing the exudation of burn wounds.

Infrared rays are also often used for sprains, to promote tissue swelling and hematoma dissipation, as well as to reduce postoperative adhesions, promote scar softening, reduce scar contractures, etc.

Disadvantages: Because the eyeball contains a lot of fluid, it absorbs infrared rays strongly, so a certain intensity of infrared rays can cause cataracts when directly irradiating the eyes. The production of cataracts is related to the action of short-wave infrared rays; Infrared rays, which have wavelengths larger than microns, do not cause cataracts.

So don't shine infrared light directly on other people's eyes!

The visible light we see is the best, and when it is rare, ultraviolet light kills and kills, and infrared grilled meat.

It's not that the higher it is, the more difficult it is to see, it's just that it's hard to pinpoint the location of the object's shadow.

The sun is the light source, the plane is the shading body, the ground is the projection ground, the plane flies at a height of several thousand meters, the shadow is cast on the ground, it is difficult to see, and the light has a diffraction type, the light can bypass the plane to the ground, the shadow disappears, mainly depends on the size of the aircraft and the height it is at.

In addition, the speed of the plane itself is extremely fast (we can't see it on the ground), and the speed of its shadow is several times the speed of its own speed, which is difficult to capture.

The first meaning: "single" in "single", refers to a certain heroic act, such as wearing only a single coat in the ice and snow, it can be said to be "single". Here the "singles" are generally not children.

The second meaning: the folk call the ruffian scoundrel a type of character "single", which has been popular in the Yuan Dynasty. For example, there is a wedge in "Yuan Qu Xuan: Killing Dogs and Persuading Husbands":

But I believed in these two bachelors, and I broke my family. In the Ming and Qing dynasties, the name of "single" was quite popular and became the official term for hooligans, and there was a "singleton case" in the "Great Qing Law" to deal with hooliganism.

After the term "single" is born, it refers to an adult who is not married and has no offspring. Men who have lost their wives are generally not called "singles," and people who have children and daughters are not called "singles." Singles' Day is a holiday for singles.

China has always attached great importance to the reproduction of children and grandchildren, and there is a metaphor for the abundance of branches and leaves. Parents are tree trunks, children are branches and leaves, and "single" refers to a tree trunk without skin, and a tree trunk without skin naturally cannot grow branches and leaves, that is, it means that there are no children and grandchildren, and because there is no wife, there are no children and grandchildren. In this way, it is understandable that "single" refers to people who do not have wives.

1. The law of gravitation may not apply to the generalized universe, so Einstein's general theory of relativity is applied2. Light does have mass, and the composition of photons includes all kinds of rays, but it is negligible3. Magnetic energy, thermal energy, and electrical energy are energy concepts and have no mass.

You can check out the "20 Years of Hubble" documentary.

Light is made up of particles that have energy and no mass.

Thermal energy and electrical energy also have no mass.

But force has quality.

Oh, a thoughtful child, study hard, I wish you all the best in your studies.

Light is one of the fundamental particles that make up the universe and belongs to neutrinos, which make up most of the mass of the universe. So light has quality.

Everything will be different in certain places, so there is no absolute "right".