Light pollution is the presence of unwanted, inappropriate, or excessive artificial lighting. In a descriptive sense, the term light pollution refers to the effects of any poorly implemented lighting, during the day or night. Light pollution can be understood not only as a phenomenon resulting from a specific source or kind of pollution, but also as a contributor to the wider, collective impact of various sources of pollution.
Sark is a part of the Channel Islands in the southwestern English Channel, off the coast of Normandy, France. It is a royal fief, which forms part of the Bailiwick of Guernsey, with its own set of laws based on Norman law and its own parliament. It has a population of about 500. Sark has an area of 2.10 square miles (5.44 km2). Little Sark is a peninsula joined by a natural but high and very narrow isthmus to the rest of Sark Island.
The Pic du Midi de Bigorre or simply the Pic du Midi is a mountain in the French Pyrenees. It is the site of the Pic du Midi Observatory.
Skyglow is the diffuse luminance of the night sky, apart from discrete light sources such as the Moon and visible individual stars. It is a commonly noticed aspect of light pollution. While usually referring to luminance arising from artificial lighting, skyglow may also involve any scattered light seen at night, including natural ones like starlight, zodiacal light, and airglow.
The International Dark-Sky Association (IDA) is a United States-based non-profit organization incorporated in 1988 by founders David Crawford, a professional astronomer, and Tim Hunter, a physician and amateur astronomer. The mission of the IDA is "to preserve and protect the night time environment and our heritage of dark skies through quality outdoor lighting."
The dark-sky movement is a campaign to reduce light pollution. The advantages of reducing light pollution include an increased number of stars visible at night, reducing the effects of electric lighting on the environment, improving the well-being, health and safety of people and wildlife, and cutting down on energy usage. Earth Hour and National Dark-Sky Week are two examples of such efforts.
Goldendale Observatory State Park is an educational facility on the northern side of Goldendale, Washington, notable for its unusually large public telescope. The state park occupies five acres (2.0 ha) atop a 2,100-foot (640 m) hill.
In the field of physical security, security lighting is lighting that intended to deter or detect intrusions or other criminal activity occurring on a property or site. It can also be used to increase a feeling of safety. Lighting is integral to crime prevention through environmental design. A 2019 study in New York City found that the provision of street lights, an important type of security lighting, resulted in a "36 percent reduction in nighttime outdoor index crimes."
International Dark Sky Week is held during the week of the new moon in April, when people worldwide may turn off their lights to observe the beauty of the night sky without light pollution. This event was founded in 2003 by high school student Jennifer Barlow of Midlothian, Virginia. It has been endorsed by the International Dark-Sky Association, the American Astronomical Society, the Astronomical League, and Sky & Telescope.
The Mont Mégantic Observatory is an astronomical observatory owned and operated jointly by the Université de Montréal (UdeM), and the Université Laval (ULaval). Founded in 1978, the observatory houses the second largest telescope in Eastern Canada after David Dunlap Observatory near Toronto. It is situated at the summit of Mont Mégantic, the highest point of Eastern Canada accessible by car. OMM is about 60 kilometres (37 mi) east of Sherbrooke and 190 kilometres (120 mi) east of Montreal.
Astronomy Now is a monthly British magazine on astronomy and space. According to the Royal Astronomical Society, Astronomy Now is the "principal amateur astronomy magazine in Britain" with a reputed circulation of 24,000.
A dark-sky preserve (DSP) is an area, usually surrounding a park or observatory, that restricts artificial light pollution. The purpose of the dark-sky movement is generally to promote astronomy. However, astronomy is not the only objective of conserving a dark sky. A dark night sky is associated with many facets of history, philosophy, religion, societal development, poetry, song, mathematics, and science. Different terms have been used to describe the areas as national organizations have worked independently to create their programs. The International Dark-Sky Association (IDA) uses International Dark Sky Reserve (IDSR) and International Dark Sky Park (IDSP). A third designation, International Dark Sky Sanctuary, was introduced in 2015.
The Bortle dark-sky scale is a nine-level numeric scale that measures the night sky's brightness of a particular location. It quantifies the astronomical observability of celestial objects and the interference caused by light pollution. John E. Bortle created the scale and published it in the February 2001 edition of Sky & Telescope magazine to help amateur astronomers evaluate the darkness of an observing site, and secondarily, to compare the darkness of observing sites. The scale ranges from Class 1, the darkest skies available on Earth, through to Class 9, inner-city skies. It gives several criteria for each level beyond naked-eye limiting magnitude (NELM). The accuracy and utility of the scale have been questioned in recent research. The table below summarizes Bortle's descriptions of the classes. For some classes, there can be very drastic differences from one class to the next, e.g, Bortle 4 to 5.
CieloBuio-coordinamento per la protezione del cielo notturno is a non-profit organization that operates in Italy for the protection of the night sky by promoting a culture of eco-friendly lighting and raising public awareness about the phenomenon of light pollution.
Globe at Night is an international scientific research program that crowdsources measurements of light pollution in the night sky. At set time periods within each year, the project asks people to count the number of stars that they can see from their location and report it to the project's website. The coordinating researchers compile this information to produce a public, freely available map of global light pollution. By September 2011, almost 70,000 measurements had been made. The use of data collected by the public makes the program an example of citizen science. Globe at Night began as a NASA educational program in the US organized by the NOAO, and was expanded internationally during the 2009 International Year of Astronomy; it is an offshoot of the GLOBE Program, which focuses on school-based science education.
Hong Kong has been named the world's worst city for light pollution. Commercial and residential areas Mong Kok, Tsim Sha Tsui and Causeway Bay are found to be the most severe areas of light pollution. Due to the spotlights and LED billboards, Hong Kong’s sky is many times brighter than other cities.
The End of Night: Searching for Natural Darkness in an Age of Artificial Light is a 2013 non-fiction book by Paul Bogard on the gradual disappearance, due to light pollution, of true darkness from the night skies of most people on the planet. Bogard examines the effects of this loss on human physical and mental health, society, and ecosystems, and how it might be mitigated.
Robert P. King, born August 9, 1953, is an American photographer, writer, and an amateur astronomer. He publishes an astronomy blog called Astro Bob which is "widely read and respected" according to astronomer Bob Mizon.
The spectral G-Index is a variable that was developed to quantify the amount of short wavelength light in a visible light source relative to its visible emission. The smaller the G-index, the more blue, violet, or ultraviolet light a lamp emits relative to its total output. It is used in order to select outdoor lamps that minimize skyglow and ecological light pollution. The G-index was originally proposed by David Galadí Enríquez, an astrophysicist at Calar Alto Observatory.
Light pollution is the presence of unwanted artificial light that brightens the night sky. Improperly shielded lights are the source of many of the issues regarding the light pollution in Hawai'i. Urban centers in the cities are often so bathed in light that over a hundred kilometers from the city's edge, the light pollution resulting from the glow is present. Fabio Falchi is quoted as stating that “light pollution is one of the most pervasive forms of environmental alteration” due to its destructive nature in both un- and protected areas such as national parks. Dark night skies are an important natural, cultural, scientific, educational, and economic resource for Hawai‘i.
