The child asks, The water is transparent, so how do we see it?

This tells him that transparency is not colorless, transparency means that we can see other things through it, and the thickness of the water determines its transparency, so we can see it.

In fact, water is a liquid that can be seen and touched by humans, and water is refractive and reflective, through which we can know that water can be seen and existed, but generally we cannot see the cleanliness of water.

The human eye can recognize colors, which also include transparent colors, and when we see colors, we can get the color of colors through the analysis of the brain, not only to see, but also to perceive.

Water can be seen because it is not completely transparent. It has a physical body. There is movement, then water is such a substance that can be seen by humans and grasped by humans.

Usually the surface of the water we see is transparent and colorless, but water can also flow. At the end of the day, the water we see is in a dynamic form.

The reason why water is colorless and transparent is that the gaps between the water molecules are so large that light can penetrate directly, hit objects behind the water, and then reflect back into our eyes.

A solid substance that neither absorbs nor scatters light makes it appear transparent. Pure silicon is extremely absorbent of light: this is because the electrons in pure silicon absorb visible light and achieve energy level transitions.

The electronic structure of a solid state can explain why the metal shines, and the reason why pure metal reflects light rather than transmits light is because it is filled with a large number of free electrons, and these electrons will radiate the incident light in the opposite direction, thus blocking the light that wants to go all the way forward, and thus preventing transmission.

What appears to the naked eye to be a homogeneous material is actually made up of many very small crystal domains, and the boundaries between these grain domains are called grain boundaries, and if the distance between the grain boundaries is smaller than the shortest wavelength of visible light, then the material appears to be transparent. Each grain boundary scatters light through it; However, if the crystal domains are small enough, light waves can actually "jump" directly over them.

Water is opaque, in fact pure water is pale blue, which is related to the degree to which water absorbs electromagnetic waves of different frequencies in visible light. The reasons for this are complex, and I won't go into detail here, but the phenomena are as follows. The greater the depth of the water, the more obvious the blue color is, for example, the sea we see is blue, because there is enough water in the ocean, so it can show blue, but in life, because the amount of water we use is relatively limited, we cannot feel the change in color, so we think that water is a colorless and transparent liquid.

Light enters the lens of the eye and acts as a convex lens. It imagines the object onto the retina, which is then processed by the pyramidal cells and the nervous system so that we see the object. Medium in general has a property that we call transmittance.

It means the ability of light to penetrate a medium. Water is a special thing. Because it is colorless, it has a very high transmittance to light, or we say it is transparent.

In fact, since light can pass directly through water, very little light is reflected back.

While our eyes need to see enough photons to see objects, water only reflects very faint light, so we can't see it. Objects can both emit light on their own and reflect light. In his eye, light is shone into a lens in the eye, similar to a convex lens, which can image these objects or reflected light to the retina, connect them through the pyramidal cells in the eye and the nervous system in the eye, and send signals to the brain that can make us aware of one of the things I see.

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This is because the water we see every day is very rich in minerals, and the water has reflective properties, and our glasses have a good sense of acceptance of reflective things, so we can see water.

I think this is a very normal phenomenon, because the human eye can see water, and water is also a very special substance, so we can see water.

Because water is a flowing liquid, we can see it while it flows, so this is also easier to understand.

This is because although water is transparent, water has a form, and we can see the liquid form of water.

This is due to the high light transmittance of water, and it is usually packed in a container or river, and the light shines on the water-filled reflector and then reflects back, enters the human eye, and can be seen.

Because of the refractive effect of water, and there are many impurities in the water, these impurities are just invisible to our eyes, and these impurities are refracted by light in the water, allowing us to see the water.

What we see is not the color of the water, but the whole volume of the water, or we see something else through the water and feel the presence of water.

Sunlight is made up of seven colors of light, and the color of a transparent object depends on the color it can pass through. We use transmittance to describe transparency. Transparent objects have higher transmittance.

There are almost no objects with 100% transmittance. In addition, even though it is the same transparent object, different objects have different wavelengths of light due to their different compositions, internal structures, etc. Substances that almost all colored light can pass through are considered colorless and transparent.

The human eye perceives the world by perceiving light. The object either emits light on its own or reflects the light of other **. The lens in the eye acts like a convex lens that focuses or reflects light emitted by objects in the line of sight onto the retina, where the optic nerve cells are responsible for perceiving color, brightness, saturation, and more, ultimately forming the world in our brain.

We see water because it reflects or refracts light, which changes direction, so the brain knows that water is there, not because the eyes see it, but because it reflects or refracts light, and it is inconsistent with the original path of propagation, and therefore judges the existence of water. We can't see the air because the air refracts or reflects light so little that we can't feel it.

The water appears transparent because the light has a small decay rate in the water. The same is true for air, but the rate of decay of light in air is somewhat smaller, judging by the speed at which light travels in air and in a vacuum. If the light travels far enough in the water, the water is not transparent.

For example, the deep ocean does not look transparent. The absorption of light by water is the main cause.

We live in the air, and since the air does not reflect light, we cannot perceive the presence of air by sight. If there is cold air or hot air, we can see that there is gas moving, and this is because the path of light has changed. The air can also be seen, and if you look at something red-hot, you will see a stream of heat floating upwards.

Because we judge the existence of water by the changes that light produces after reflection and refraction in water, which contrasts with the surrounding environment. I also saw the water.

Because water is moving, not flat and stationary. And there will be reflections and refractions of light. So you can see the presence of water.

Although the water is colorless and transparent, it is not gaseous, but liquid, so we can see it.

The water is transparent, why can we see it, do you know what the reason is?

Although water is transparent, everything we see is reflected by light, and the wavelength of such a color is within the range of human vision, so we can see the color of water.

Even though it's transparent, we can still see the water. We can see things because things reflect light, and water can reflect light, so we can see, water is transparent, but water contains a lot of impurities, but it is not easy for us to see with the naked eye, and it can reflect natural light.

Because a layer of water mold is formed on the surface of the water, in the case of light, there will be light that reflects the state of the water surface to our eyes, so the eyes perceive the presence of water, but do not directly see the transparent water.

That's because water can refract light, so you can see water, and on the other hand, because it's not pure, and there are some minerals or bubbles in the water, so you can see it.

This should be based on the principle of optics. We see transparent water because it can refract light, and when it gets into the lens of the eye, we can form a three-dimensional image.