Have you stargaze in the middle of night? When you look up, maybe you’ll see the beautiful formation of the stars or the opposite, the glow sky caused by light pollution. Our star-filled night are fading away and for the first time in human history, most people live where they can’t see the Milky Way. The worst thing is many of them have no idea what they’re missing.
Amateur astronomers know the problem well. Their observation night can be ruined by the appearance of light glare over the backyard. If it happens to you, what should you do?
Light Pollution: When Light is More Than We Need
In 1879, the Thomas Edison’s incandescent light was first time illuminate the street in New York and the modern era of electric lighting began. Since then, our globe fulfilled with electric light. Human tendency as diurnal being tried to lengthen their activity in night hour. So it makes the using of light increasing rapidly. Almost all infrastructure completed by outdoor lighting, such as street, parking lots, house and building, and billboard. Beside for filling the light requirements, outdoor lighting also use for aesthetical purpose.
Artificial light has a lot of benefit for our society, for instance, extending the length of the productive day, giving more time not just for working but also for recreational activities that require light. But when artificial light especially outdoor lighting becomes inefficient, annoying, and unnecessary, it is known as light pollution. Many environmentalist, naturalist, and medical researches consider light pollution to be one of the fastest growing environmental pollution and can have effects on both human body and wildlife.
Light pollution comes in many forms, such as sky glow, light trespass, glare, and over illumination. Sky glow is the bright halo that appears over urban areas at night, the lights are being scattered by water droplets or others particles in the air. Light trespass occurs when unwanted artificial light, like streetlight, lighting an area than would be dark. When your neighbour’s lamp enters your room when you’re sleeping, it is one example of light trespass. Glare is created by light that shines horizontally. Over illumination refers the using of artificial light is more than required, such as keeping the light on all night in an empty office building.
The Significance of Light Pollution
Light pollution problems involved three categories: ecological, human, and economic. Ecological problems involve the behaviour of animals because the level of nocturnal lighting coming for human artificial light. Sea turtle is one of dramatic example of how artificial light on beaches can disrupt behaviour of animals. Sea turtle hatchlings normally navigate toward the sea by orienting the dark silhouette of landward horizon. When there are artificial bright light on the beach, newly hatched turtles become disoriented and navigate toward the artificial light source, never finding the sea. Disoriented problem also occur to birds. Each year in New York City, about 10.000 migratory birds are injured or killed crashing into skyscrapers and high-rise building.
Many of studies reveal that the wildlife and the presence of moonlight have high dependence. The moonlight tells the animal time for nesting or breeding, or looking for food. The problems start when levels of artificial lighting from human begin to approximate levels of light that would typically originate from moon, but on moonless night. Their behaviour of nesting, breeding, and feeding are involved by artificial light.
The consideration for human can involve physiological and psychological. The 24-hour cycle, known as circadian clock, affects physiologic processes in almost organism. Using light to extend human activity on the night can affect the circadian clock. Disruption of the circadian clock is linked to medical disorders including depression, insomnia, cardiovascular disease, and cancer, especially breast cancer.
Numbers of researches believe that melatonin may be the key to understanding the breast cancer risk. Melatonin is a hormone produced by the pineal gland, is secreted at night and is known for helping to regulate the body’s biologic clock. The body produces melatonin at night and melatonin levels drop precipitously in the presence of artificial or natural light. The decreasing nocturnal melatonin production levels increases an individual risk of cancer.
The economic problems of light pollution involve the costs associated with the inefficient outdoor lighting. The burning of natural resource, like coal, in order to generate electricity causes atmospheric emission, such as carbon dioxide, that represents the final cost of light pollution.
Do an Effective Lighting!
We can reduce light pollution is such an easy way, just by shield all outdoor lamp. 50% of the light from typical unshielded light is wasted, shining upward where it is not needed. About 40% of the light shines downward to illuminate the target. Light emitted horizontally tends to create glare. Glare and light upward can fill space with light, but they may be too bright and much of the light is wasted. As another result, the beautiful star-filled sky can’t be seen.
Good lighting is shielded in a manner that all the light where it is needed and wanted. All lighting be installed such that no light is emitted above horizontal line. By requiring lights to be shielded and oriented downward, can make the light from the bulbs more efficient san cost saving until 50%. Fully cut-off lamp help to eliminate light pollution by decrease non useful light to the sky up to 90%.
A further recommends the use of low pressure sodium (LPS) light wherever possible. LPS light are the most energy efficient lights currently available. The most important and easy way is turn off the light when it’s not being used. And you can do more by educate your neighbour, your family, and elected official.
The sky is changing, from the star-filled sky to light-flooded sky. We still can change back the sky, by do some easy way by use light as effective as possible. The stars and the universe above us begged to be seen. Now is your turns, do nothing or do something.