What is the difference between sunset, sunset and dusk?

Sunset refers to the sun in the evening, also refers to the west of the mountain, and is also used as a metaphor for old age;

The sunset refers to the sunset;

Dusk refers to the time after sunset until it is not completely dark. The second finger is yellow and the light color is dark.

2. The occurrence time is different

Sunset first occurred at dusk when it was getting late;

Sunset is next, because it is close to dusk, it is generally orange-red;

Dusk occurs at night after the sun has completely set 19 ~ 2 1.

Extended data:

Astronomers have long discovered that the earth's atmosphere scatters light. 187 1 year, British scientist Rayleigh proved that the scattering of short-wave light is much stronger than that of long-wave light. Therefore, the intensity of short-wave light-violet light scattered by tiny dust and air molecules in the atmosphere is more than 10 times that of long-wave light (which can explain why the sky is always blue).

Because at sunset and sunrise, the atmosphere penetrated by sunlight becomes thicker, and yellow and red light have the greatest penetration ability, so the sun at this time looks dark yellow and crimson. Generally speaking, there is more smoke and dust in the air at dusk than in the morning, so the color of sunset is different from that of rising sun.

Because the earth's surface and atmosphere are curved, the distance of the sun's light passing through the atmosphere near the horizon is much longer than that of the upper layer, so the light entering the bottom layer decays quickly, and the shadow of the earth caused by the sun sinking into the horizon appears blue-gray dark arc in the sky; However, the upper atmosphere has a low density and weak light scattering, which leads to a bright arc on the dark arc.

This wonderful atmospheric optical phenomenon rises to the zenith with the setting of the sun and disappears with the arrival of darkness. As for the beautiful purple light, it is caused by the superposition effect of human eyes, which makes the red light passing through the atmospheric dust overlap with the blue scattered light of the purer air in the upper atmosphere.

The illusion that the sun is flat appears not only at sunset, but also when the sun jumps out of the horizon. This is because when light passes through the air, the speed slows down by 87 kilometers per second, so the refraction of light changes accordingly. Therefore, when the lower edge of the sunset touches the horizon, the ratio of the height to the width of the sunset is 26.5 ∶ 32 through refraction, and the sun in the eyes of the viewer is naturally flat.

The most puzzling illusion is that the sun at sunset looks two and a half to three and a half times bigger than it did at high altitude, just like a huge jade plate hanging in the distance of the horizon. But in fact, astronomers outside the atmosphere have used various instruments, including cameras, to prove that the sun at dusk is the same size as the sun at noon.

References:

Baidu encyclopedia-sunset

References:

Baidu encyclopedia-sunset

References:

Baidu encyclopedia-dusk