Lead
The concept of an "artificial moon" is not new, it is based on many ancient mythological solar artifacts and moon instruments, and even some modern science fiction works.
There has always been hope that there would be a brighter moon to illuminate the night, or that a brighter sun could bring more light to the day, but these assumptions were ultimately unrealistic.
However, since the launch of artificial satellites in the last century, the scientific and technological level of human beings has been developing rapidly day by day, and the powerful functions of artificial satellites have also been recognized.
What is the brightness of the natural moon?
How is an artificial moon realized?
1. The appearance of an artificial moon.
The brightness of the natural moon is not the same as the brightness of other light sources we see in our daily life, and the "lumens" we usually use is a unit used to quantify the brightness perceived by the human eye, while the brightness of the natural moon is not measured by lumens, but by "lux".
The luminous flux of 1 lumen, after passing through an area of 1 square meter, is the brightness of 1 lux.
So, what is the brightness of the natural moon?
The brightness of the natural moon is 0.25 lux.
The human eye has an adaptation period of about 5 minutes to the brightness of 0.25 lux, and after the eyes get used to it, they can see the surrounding environment clearly, but before that, it takes a while for the human eye to adjust from strong light to weak light, in this process, people will feel that the surrounding light is very dark, but to be precise, people just adapt to the light process, the eyes have an illusion.
The brightness of an artificial moon can reach 2 lux, which is far beyond the scope of adaptation for humans, so theoretically speaking, an artificial moon is impossible to achieve.
So where did the idea of an artificial moon come from?
The idea of creating an artificial moon originated from ancient mythology.
In "Zhuangzi • The Great Master", there is such a passage: "
Only the sun is only the yin, only the sun is only the moon, only the light is dark, only the first is the last, only the light is only the ignorance, only the light is the light, only the light is only the light.
Only the sun is bright, only the big is small, only the dark is bright, only the ambiguous is clear, only the yin is only the yang.
Only light and shadow, only day and night, only obscurity, only moon and sun, only heaven and earth, only life and death, only observation, only star, only night and day. ”
This passage links day and night, cloudy and sunny, the sun and moon, the stars, and the relationship between light and darkness.
Words such as "Zhao" and "Zhao" are all related to light.
The ancients called the sun and the moon and other lights "bright and extinguished", and the interaction between these light sources was also called "yaozhao" or "zhaoying" by the ancients.
The ancients called the brightness of the stars "Yao", and when someone invented the lamp, they called the light of the lamp "light".
The ancients also found a lot of ways to realize artificial light sources, and some people simply put oil lamps or candles on a high shelf to illuminate the surrounding environment, and this method can indeed achieve lighting, but the effect is not very good.
When people started using oil lamps, some people wanted to shine farther light, so some people installed oil lamps on a rotating device so that they could emit a circle of light, so that the light of the oil lamps could illuminate a larger area.
In the 20th century, electric light was widely used, and some people put forward the plan to use electric light as an artificial moon, and eventually, the plan of an artificial moon was developed into a space lighting system, and there is a space lighting system called "artificial moon" in Russia This system is composed of reflective satellites, they are composed of a launch satellite and a series of free-flying satellites, the launching satellites will launch other satellites into space, the satellites will fly freely with each other, emitting a circle of light, you can illuminate the ground, which can make the light at night 2.5 times stronger, thereby reducing the light pollution on the ground.
Second, the plan was shelved.
Russia's plan, although it looks good, has some serious problems.
First of all, although this project can illuminate the ground, the light emitted by the satellite will still affect the stargazing environment in the sky.
Secondly, the planned satellites are all free to fly, which means that wherever the satellites fly, they will illuminate wherever they fly, and they will illuminate wherever they fly, which means that the planned satellites may fly to those places with serious light pollution, aggravate pollution, and may even fly to places with populations to illuminate people's lives.
In this way, the light of the artificial moon may have an impact on the biological clock of living beings, and it may have an impact on the body's menstrual cycle and sleep, and these satellites are all free-flying, if one of the satellites has a problem, or the satellites collide with each other, a large amount of space junk will be generated, and it may even drop the satellites down and cause damage to the ground.
These problems, in the end, were not solved either, and this Russian plan was not realized, but was shelved after 1999.
China has a similar plan, this plan is to launch a large high-altitude reflector, in 2002, China tried to launch a large high-altitude reflector, trying to illuminate the city at night through reflection, but this plan was not realized due to the complexity of the reflection conditions and the lighting conditions on the ground.
China has a more accurate "artificial moon" plan, which was proposed in 2018, in which the artificial moon is composed of light emitted by satellites, and there is only one satellite, but it can send out eight free-flying satellites, and the satellites will fly to a predetermined position and project light onto the ground, so that it can illuminate a certain range of ground and reduce light pollution on the ground.
Does this plan look a little better than the Russian one?
Although the number of satellites has been reduced and the range of illumination has been reduced, there are still some problems that have not been solved.
First of all, although the number of satellites has decreased, collisions between satellites will still produce a large amount of space junk, which may also hit other satellites, causing more debris and eventually affecting satellite communications on the ground.
Secondly, although the light of the satellite can reduce the light pollution on the ground, because the flight trajectory and speed of the satellite are difficult to predict, the light of the satellite is also unpredictable, even if the flight trajectory and speed of the satellite are taken into account, it may not be able to predict the light range of the satellite, so that a large amount of light pollution will be generated, which will affect the stargazing environment of the sky.
3. The reason why the artificial moon has not been realized.
The plan for an artificial moon looks good, but it also has too many problems that could have an impact on the ecology and life of the earth, so the plan has not been realized.
Although the plan for an artificial moon has not yet been realized, it may be revealed one day in the future, after all, the technological level of mankind is still improving.
But in the future, once the artificial moon is realized, people need to control its light range to reduce light pollution, and the light of the artificial moon will also have an impact on the life and ecology on the ground, and people also need to study these effects to reduce the impact on biology and ecology.
Once the artificial moon is realized, people's night life will also change, now the city night, many people are sleeping, many places are open, but if the light of the artificial moon can change the light of the night, then people's night life will also be affected, people may change the night schedule and activities, which may change people's cultural habits, may bring some social and psychological problems.
Although the plan for an artificial moon has not yet been realized, people are open to it, and as long as people have interests, this plan will be realized.
However, the plan for an artificial moon also needs to weigh the pros and cons, rather than blindly pursuing new technologies, so that the plan for an artificial moon may still be shelved.
epilogue
Although the plan for an artificial moon has not been realized, people are open to it, and as long as the technology is mature, it may be realized.
Even if the artificial moon can illuminate the ground at night in the future, it does not mean that we can ignore the natural moon, although the artificial moon can illuminate the ground, but it will also have an impact on the natural moon and the starry sky, so we still have to protect the natural moon and starry sky and maintain the ecological balance of the earth.
As practitioners of science and technology, we also need to think deeply about the plan for an artificial moon and weigh the pros and cons to avoid irreversible damage.