recently

The sky of Yunnan

staged a shocking visual feast

A blood-red sun hung in the sky

Related topics quickly became the first hot search

It has aroused widespread concern

on social media

A lot of Yunnan netizens

have posted the blood-red sun they have photographed

On the curtain

The sun has faded from its usual golden glow

Instead, it turned into a crimson halo

Some netizens described it

"Intense as blood, smudged as ink at the edges"

Social media screenshots

In the comment area

Some netizens think that the sun color is too bright

Something doesn't seem right

meanwhile

There are also many foreign netizens who "show up to say"

Post a daily photo of the red sunrise and sunset

Pointing out that "red suns are rare, but they are not supernatural"

There are even netizens who associate it

This is similar to the French impressionist painter Monet

The "Sunrise Impression" is the same

Lamenting that "art can predict nature"

Sunrise Impression

In that case

How did the "Red Sun" come about?

Follow in the footsteps of journalists

Let's go deep into the back of this magic of light and shadow

Discover the mysteries of the atmosphere, light, and the Earth's environment

Science Decoded: How does the atmosphere "magic" the sun?

Schematic diagram of light scattering (video screenshot)

To uncover the mystery of the "blood-red sun", you first need to enter the atmospheric optical theater and watch the magic of light and dust.

1. The "hierarchical selection" of light: the game of scattering and refraction

Sunlight spectrum (Source: China Science Network)

Sunlight is originally a "white light" composed of a seven-color spectrum, and the atmosphere acts as a dynamic "filter" that changes its color through scattering and refraction. Thereinto:

Rayleigh scattering: When sunlight passes through the clean atmosphere, the blue and violet light of short wavelengths are easily scattered by the tiny molecules in the air (such as nitrogen and oxygen) to form a blue sky, while the red light can reach the ground directly due to its long wavelength and strong penetrating power. When the sun is high at noon, the light passes through a thinner atmosphere, blue light scatters significantly, and the sun appears white.

Mie scattering: Scattering patterns change when there are large particles in the atmosphere (e.g., dust, soot, water droplets). These particles scatter short-wave light more efficiently, while red light is less affected by scattering due to its long wavelength and becomes the dominant color.

According to the analysis of experts from the Yunnan Astronomical Observatory of the Chinese Academy of Sciences, the appearance of the "blood-red sun" in Yunnan may be caused by atmospheric scattering and refraction. On that day, there may be more dust, water vapor and other particles in the atmosphere, scattering and refracting sunlight, among which the blue and violet light with shorter wavelengths are scattered more, while the red light with longer wavelengths has strong penetrating ability and reaches the ground more, making the sun appear blood-red.

It is worth mentioning that this phenomenon is similar to the principle of "burning clouds": at sunset after a thunderstorm in summer, when there is enough moisture in the sky, the sunlight is scattered and refracted when it passes through, and a red glow is formed.

2. Extended Filter for Ray Path

In the evening, as the sun approaches the horizon, sunlight passes through a thicker layer of the atmosphere. The longer the path, the higher the chance that the short-wave light will be scattered, and the proportion of red light will increase. If the concentration of particulate matter in the atmosphere is "just right" at this time, this effect will be amplified, resulting in a rare "blood red sun".

Environmental Context: A "Polyphony" of Factors such as Nature and Seasons

At this time, some netizens were curious: "Is it because the air quality is poor and the pollution is serious that the blood-red sun will appear?" ”

Not exactly.

The China Meteorological Administration's popular science has mentioned that when there are many particles larger than air molecules (such as dust and water droplets) in the atmosphere, Michaelis scattering will dominate, and the short-wavelength light will be scattered in large quantities, and the red light can be retained.

But these particles can come from natural processes, such as dust from the ground, small droplets of water vapor condensation, and not necessarily pollution.

In response to the situation in Yunnan this time, experts speculate that it is the particulate matter in the atmosphere that is "just right"!

　　專家指出，每年3月至4月，雲南常受幹季氣候影響，逆溫層頻現，導致污染物在近地面聚集，天空呈現“灰濛濛”狀態。而近期可能受到局地降水或風力作用，讓空氣中的水汽和塵埃含量升高，加上太陽處於低角度，光線路徑長，才讓紅光被強烈放大。

Far from unusual

It is not associated with earthquakes

It is important to note that this phenomenon is not unique to Yunnan:

In 2019, due to severe air pollution, the sky in some parts of Indonesia was scattered red by particles produced by burning banana trees, causing the sky to appear blood-red.

In the year 2020 wildfires in California, the sky of San Francisco was dyed orange-red by smoke and dust.

It can be seen that when the atmospheric conditions are "together", it is possible to stage an optical spectacle.

However, some people are worried: "Could the blood-red sun be related to earthquakes?" ”

In response, experts have made it clear that there is no historical evidence to support such associations.

Be rational: Such phenomena should be viewed with a scientific attitude

The fading of the "blood red sun" left the public not only with visual shock, but also with a profound scientific enlightenment. Experts urge everyone to take a scientific approach to natural phenomena and avoid over-interpretation or the dissemination of unsubstantiated speculation.

Many of the wonders of nature have their roots in the physical sciences: from the aurora to the rainbow, from the mirage to the "blood sun", these phenomena are all the result of the collision of light, atmosphere and geographical conditions;

Beware of the trap of "supernatural narratives": human instinctive fear of the unknown can easily breed rumors, and only scientific literacy can anchor rational cognition.

When Yunnan's "blood-red sun" becomes a trending headline, we might as well think of it as a vivid nature lesson: it reminds us that the romantic wonders of the universe are often hidden in physical formulas and chemical equations. The next time we look up at the sky, perhaps we will be less frightened and more in awe and exploration of the laws of nature.

[Know more]

Scarlet Sisters: The moon will also turn red

　　2018年7月28日在內蒙古自治區烏蘭察布市拍攝的月全食。（來源 新華社 馬勁 攝）

The Super Red Moon is a peculiar astronomical phenomenon that is related to the refraction and scattering of sunlight by the Earth's atmosphere.

When the sun, the earth, and the moon are perfectly aligned, the earth blocks the sunlight that directly hits the moon, but the earth's atmosphere will act like a "lens" to refract the more penetrating red and orange light in the sunlight to the surface of the moon (short-wavelength light such as blue light is scattered by the atmosphere), so that the moon appears orange or even red, and the color shade is affected by factors such as volcanic ash and pollutants in the atmosphere. This phenomenon is only visible during the total lunar eclipse phase.

Source: CCTV Finance

In addition, the Moon may also be reddish as light passes through a thicker layer of the atmosphere as it approaches the horizon (similar to the sunrise and sunset principle). Although the blood moon is often seen as a mystical omen in culture, modern science has made it clear that the natural nature of the moon allows the public to observe this astronomical spectacle directly with the naked eye without special protection.

Transferred from: Open Screen News

Source: Pocket Spring City