An expository essay on light, an expository essay on light

Light is a type of electromagnetic wave that can be seen by the human eye, also known as the visible spectrum. In the scientific definition, light refers to all the electromagnetic spectrum. Light is composed of photons as elementary particles, which have particle and wave properties, which is called wave-particle duality.

Light can travel in transparent substances such as vacuum, air, water, etc. There is no clear limit to the range of visible light, and the wavelength of light that the average human eye can accept is between 400-700 mm. People see light from the sun or with the help of devices that produce light, including incandescent light bulbs, fluorescent tubes, lasers, fireflies, etc.

Because light is an indispensable substance for human survival, there are many idioms of light.

Faster-than-light (FTL) or superluminality is a topic of discussion, which stems from the theory of relativity, which limits the inference that local objects cannot exceed the speed of light c in a vacuum, and the speed of light becomes the upper limit of the rate in many cases. Prior to this, Newtonian mechanics did not limit the speed of light. In the theory of relativity, the speed of motion is closely related to other properties of the object, such as the mass and even the passage of time in the frame of reference in which it is located, so that an object with a speed below the speed of light (in a vacuum) will have its mass grow to infinity and therefore require infinite energy, and the passage of time it perceives will even stop (if it exceeds the speed of light, there will be a "time reversal"), so it is theoretically impossible to reach or exceed the speed of light (as for photons, that's because they are always at the speed of light, and not from below the speed of light to the speed of light).

But it has also made physicists (and the general public) particularly interested in some physical phenomena that "seem" to be faster than the speed of light.

Current studies have shown that there are faster-than-light speeds - some stars** eject fragments, and their fragments have moved faster than the speed of light, so the speed is not fixed, fast and slow.

Academics still call the speed of light the fastest.

Objects require infinite energy to reach the speed of light, which cannot be exceeded in parallel space.

Scientists have proposed the idea of compressing the space in front of the object and expanding the space behind the object beyond the speed of light. It just takes a huge amount of energy, and existing technology can't do it.

The speed of light in a black hole should be greater than 30, so it is difficult for light to escape. But no technology can go beyond it and into a black hole.

Light travels in a straight line in the same homogeneous medium.

I think, I think, it doesn't matter how I understand the light!

The essence of light is the manifestation of the range of energy, which is visible to the human eye, and there is still a range of energy outside the light, but it is not visible with the eyes.

The heating in the living room does not emit light but heats, and heat is the invisible light of the eyes, that is, the dissipation of energy.

Radar waves are also the equivalent of invisible light. The earth does not emit light, the earth's atmosphere, and the earth's energy is also equivalent to the nature of light.

There is an end to the light! If the light were endless, there would be no night. The light of all the glowing stars in the universe does not illuminate the night of the universe because the light stops illuminating at a certain distance. No matter how far the light can shine, there is a certain end to the light.

The speed of light is 300,000 kilometers, which is just one astronomical unit of measurement. As for whether the speed of light is accurate, that's a matter for scientists. In fact, it's okay to be accurate or not, in ancient times, it was recognized that six inches is a foot, and six inches is a foot.

In modern times, ten inches is changed to one foot, and after people blindly recognize it, it is a unit of measurement that people normally use.

My light, for me, it's not bright.

Maybe you'll think I'll say you're my light. Haha, no, you're wrong. If a person takes another person as the driving force of his life, or the light of life, then he will easily lose hope in life.

So, you are not my light.

Yesterday, Sunday, I went back to Douyin because I was bored at home. Some people watch Tik Tok for fun, but I want to see what other people's lives are like recently, whether they are as monotonous and boring as me. Because I haven't seen what life in other people's ** is like for a long time, I suddenly found out in a trance that there are still too many differences in this world.

Not everyone will be happy, and not everyone will be happy. Not everyone is lucky, and not everyone is optimistic.

In this way, all these encounters also make their light different.

I really envy her courage, so real, so pure, for her youth, and for herself. I might do the same.

Spring is coming, and the spring I've been looking forward to has finally arrived. However, it was as if everything was too good, the spring breeze was very strong and fierce, more bitter than winter, and there were no tender green leaves and no new buds, only dry branches and shrunken vines. It's disappointing.

Today, Monday, people, there should always be some sense of ritual. So I'll start tonight, study hard, I haven't studied hard since April 20, I now have a kind of college entrance examination faster, get rid of the status quo of online classes at home due to the epidemic, there is a feeling of breaking the jar and falling, but at least there must be a good college entrance examination score! It's never too late to start today!