light pollution: our vanishing night skies - street light price

Those of us who live in and around the city are at best just a casual understanding of the night sky.
Astronomical objects like nebulae, star clusters, distant galaxies, and even our own Milky Way are all foreign things that can only be found in textbooks and computer desktop wallpapers.
For us, the night sky is a hazy orange mist, only occasionally dotted with the moon and stars and planets.
For thousands of years, humans have been looking for navigation, timing, and myths in the night sky --
Find out the intricate constellations from the brightest stars of the night.
Today, even the brightest stars in our constellation are washed away by the Orange night sky.
The reason why the sky in our city and suburbs turns orange is light pollution.
Unnecessary light from street lights, outdoor home lighting, billboards and car headlights leaks into the sky.
This leaking light is not only inconvenient for astronomers and astronomers.
This is a waste of energy and has some negative environmental effects on the ecosystem, as well as adverse effects on human health.
The type of light pollution is usually defined as changing the level of natural light in the environment due to artificial lighting.
From a more practical point of view, if excessive, intrusive and/or wasted light from night lighting does not meet its intended purpose, it is considered contaminated.
A practical example of this is the light in the neighbor's driveway that shines directly on the window in your bedroom --
Photons entering your house do not illuminate the lanes of your neighbors, thus polluting your home environment.
This is an example of light intrusion.
A form of light pollution.
When light from one's property invades another's property, light invades occur.
Another form of light pollution is the glare when excessive
The bright light shines directly into the eyes.
Excessive glare
Bright street lighting or high
The beam headlights of oncoming cars can be very dangerous when driving at night, and can also reduce visibility for pedestrians and cyclists.
This prompted the American Medical Association to describe this form of light pollution as a public health hazard in 2009.
Orange night sky familiar to the city (
And more and more suburbs)
Residents are called skyglow.
This form of light pollution is the most frustrating for amateur and professional astronomers, mainly caused by misleading street light scattering in the atmosphere.
The orange color of Skyglow is generated by upward scattering-
Outdoor lighting guided by air molecules (
Known as Ray Scattering)and aerosols (
Known as Mie scattering)
In the atmosphere
The negative effects of light pollution at night artificial lighting on plant and animal species, ultimately have a variety of effects on the entire ecosystem.
The main effect of light pollution is the destruction of animal circadian rhythm, and the effect of light pollution is an important example of plankton.
Many types of plankton, such as tiny shellfish, spend their days in deep water to avoid predators and their living on algae and other plankton on the surface of the water.
When the night sky is illuminated by the sky, the plankton water dragon stays below the water surface.
This causes algae on the surface to overbreed, causing algae to multiply in large quantities, to drain nutrient levels and to kill underwater plants and fish.
Turtles are another example of animals adversely affected by light pollution.
Mother turtles instinctively spawn on the beach.
After the turtle comes out of the egg, it must be visually navigated to the water, crawling to the starlight reflected on the surface of the water, rather than to the relative darkness of the land.
However, the glare of the coastal lighting confused the young chicks, who often climbed inland on the beach near the road and then died of exhaustion, hunger or being knocked down by a car.
It has been found that switching from overhead lighting to embedded road lighting can significantly improve turtle survival in many seaside communities.
Birds are another type of animal affected by light pollution.
Migratory birds can be attracted by the lights on skyscrapers and communication towers, resulting in at least 4-
According to US statistics, 5 million people die every year. S.
Fish and Wildlife Services.
During the migration season, simple measures such as changing the color of the communication tower lights and turning off the lighting of skyscrapers can help reduce bird mortality and protect endangered birds.
The impact of light pollution on health light pollution also has a negative impact on human animals.
The retina of the human eye contains not only images-
Produces light and color that can be seen, but also contains non-image-
Producing cells that can see darkness.
These cells are regulated to sense light in the dark blue 480 nm range and to regulate the production of melatonin in the pineal gland, a hormone that helps the body sleep.
When exposed to light in the blue part of the spectrum or even at low levels, these light exposures tell the pineal gland to stop producing melatonin.
Melatonin is not only a sleep regulator, but also a powerful antioxidant that removes harmful free radicals from body tissues before causing DNA damage or even cancer.
Many studies have found a correlation between the inhibition of melatonin levels and the high incidence of breast cancer, prostate cancer and other cancers, which makes light pollution pose a potential risk to human health.
The common argument between Star Night and SafetyA against darkness
We need bright Street and property lighting to stop crime.
The survey found a clear benefit.
We feel much safer in a bright place.
Bright area at night.
However, the scientific literature does not find significant practical deterrent value for outdoor lighting at night.
According to a study by the Victoria Astronomical Society in Australia, there is even some evidence that bright outdoor lighting actually contributes to crime.
The logic behind this conclusion should be quite obvious.
After all, ordinary criminals generally don't walk down the street in night clothes. vision goggles.
The same bright lights made us feel safe while waiting at the bus stop using an ATM or late at night, and also made us more visible to potential attackers.
Bright lights outside the home or business can make it easier for thieves to pry locks or climb through windows, and the glare of direct street lights can mask rather than illuminate, attackers.
This is not to say that the solution to light pollution and crime is not outdoor lighting at all --
The solution is smart lighting. Well-
Reasonable design-
Placing lamps can improve the safety of drivers, pedestrians and owners while reducing the light in the sky.
When designing an outdoor lighting plan, architects and urban planners have many options to reduce light pollution and improve aesthetics without sacrificing safety.
The key components here are the design of the lamps and the type of bulbs used.
Most street lights are designed with critical lights.
Pollution defects: they light not only the street below, but also the sky above.
The worst criminal is
Glass acorn-style light that glows in 360 degrees of light.
These not only shoot light directly into the sky without value, but also create dangerous glare for people on the ground. The drop-
The common lens street lights on many highways and suburban streets have not improved much.
The bulbs of these street lamps are usually located in the glass dome under the reflective metal housing.
While they do not glow directly into the sky, they still create glare and sky glow by sending most of the light horizontally to the ground.
The best lighting design to reduce light pollution is full
As a street lamp, the bulb is located entirely above the opening of its metal housing, leading all its light to the ground.
These greatly reduce glare, contribute the least to light pollution, and require less energy to produce the same amount of lighting as the polluting peers.
Another important factor in reducing light pollution is the type of bulb used. Metal-halide lamps -
Types for car headlights and stadium lighting arrays-
The pollution is the most serious because they produce all kinds of high
White light intensity.
And this is high.
When chasing a popular fly in a night baseball game, the intensity light is definitely useful, and it is much more than the lighting needed for a parking lot or corner. Mercury-
Steam lamps produce lower steam lamps a little better
Light of intensity but less energy
High efficiency, if the shielding is improper, it will produce dangerous ultraviolet rays.
The lights are currently being phased out in Europe, and manufacturing and installation are prohibited in the United States.
In many cases, Mercury
The compact fluorescent bulb is replacing the steam lamp.
Although these are more energy
High efficiency, they're not light-
It can cause pollution when used outdoors.
The best lamp type to reduce light pollution is lowSodium stress-
Steam lamp, producing yellow with a single wavelength-
The orange light, not the full spectrum.
These still produce light pollution when used in harsh environments
The designed enclosure is usually the source of Orange Sky Light in the urban sky.
However, they are best suited to preserve the view of the night sky as they allow astronomers to filter out this particular wavelength.
While this is not ideal, the use of these lights allows the observatory near the city such as the San Jose Valley Lick Observatory to continue working.
In the past century, the modern convenience of night lighting has always been an important part of human development, enabling us to produce around the clock.
However, there is a price for this development --
Lose our night sky.
The consequences of this loss may be beyond the scope of ecology and aesthetics.
If our Astronomical Observatory can't scan the Earth in the night sky
The consequences of light pollution can be disastrous across asteroids.