Humans are instinctively afraid of the dark. Sometimes I walk faster through the unlit streets at night imagining there are monsters under my bed. To overcome fear, you can leave a nightlight on to ward off monsters, and place a light over your porch to deter intrusions.
But while huddled for safety under a pool of light, we lost touch with the night sky. The number of stars by the public awareness campaign Globe at Night reveals that the artificial brightness of the global night sky has more than doubled between 2011 and 2022. Still, community interventions can create meaningful change.
Light pollution cuts us off from one of nature’s greatest wonders, harms wildlife and hinders research that could help fight climate change. Stars don’t just shine in the night sky. They have shaped the mythology of every human civilization. They guide the birds on their amazing migration journeys. And now, we need to do a little bit to prevent light pollution so that the stars are part of our future.
The human eye can detect approximately 5,000 stars in the night sky. But the light emitted by skyscrapers, streetlights, and houses obscures all but a handful of the brightest stars.
Our ancestors used the rising and falling of the constellations as a calendar. They also navigated the stars as they searched for new lands or followed nautical trade routes. Sailors generally no longer use the stars to navigate, but they are still taught how in case the navigation system fails.
Migratory birds, including birds and insects, are drawn away from their natural flight paths by the city’s “sky glow.” Las Vegas was invaded by millions of migratory locusts in the summer of 2019, but the beams of his 9/11 Tribute in Lights in New York attract flocks of migratory birds flying at night.
Bewildered by bright city lights, birds crash into towering skyscrapers. Insect populations are declining worldwide, and light pollution is exacerbating the situation by disrupting their nocturnal life cycles.
What is light pollution?
Light pollution is caused by the same physics that make the sky blue during the day. Sunlight is made up of all the colors of the rainbow, and each color has a different wavelength. The air that surrounds us is made up of tiny particles, such as oxygen and carbon dioxide molecules.
As light from the sun travels through the air, it is scattered in random directions by these particles. Blue light (shorter wavelengths) is scattered more than red light, which has longer wavelengths. As a result, our eyes receive more blue light from all directions in the sky.
At night, light scattered by the same air particles illuminates the sky. A small portion of this sky glow is caused by natural sources such as starlight and the Earth’s atmosphere. But most of the light that makes the sky glow is man-made.
Light pollution also affects our ability to study the universe. Even modern observatories built on remote mountaintops are affected by the intruding sky glow from growing sprawling cities. Light pollution is so widespread that he three-quarters of all observatories are affected.
look up
But there is no reason to despair. We created light pollution. we can fix that.
Across the world, the Dark Sky Association educates the public about the dangers of light pollution, lobbies for legislation to protect dark sky reserves, and promotes a harmonious relationship with dark, star-studded skies. We work to rekindle connections in people.
Light pollution control starts at home. If outdoor lighting must be left on for safety, use a shielded lamp that only shines downward. Use bulbs that do not emit violet or blue light as they are harmful to wildlife. Smart lighting controls can also help reduce your home’s impact on wildlife and make it easier to observe the night sky.
There is also an interactive map showing how polluted the skies are in your area. These maps are created by satellite-collected data and citizen scientists participating in the annual star count. You too can help darken our skies.
In the UK, the 2023 annual Star Count will take place from 17-24 February. Also, wherever he is in the world, whenever he wants, he can participate in the annual Globe at Night star count.
The task is easy. Go outside on a clear night and count and report how many stars you can see in famous constellations such as Orion.
Beating light pollution requires knowing how severe it is and what difference national policies and local interventions (such as replacing street lights in cities) can make. For example, in the UK, star counts show that light pollution peaked in his 2020 and began to decline.
Perhaps the most important aspect of star count is that it illuminates the fading night sky and inspires us to take action. Ultimately, it is up to each of us to reduce our impact on the skies by changing the way our homes and neighborhoods are lit, and by lobbying our representatives to pass dark sky laws.
Or Graur, University of Portsmouth, Leader in Astrophysics. This article is republished from The Conversation under a Creative Commons license. Please read the original article.
