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The Veiling of our Night Sky

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on 26 April 2017

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Transcript of The Veiling of our Night Sky

Light Pollution's Effect on our Night Sky
Light Pollution is a growing problem that not only effects our night sky, but also our health, wildlife and their natural habitats.
What Causes Light Pollution?
Light pollution has several causes such as improper lighting, misdirected lighting, unnecessary lighting, and excessively high wattage or powerful lighting.

How do we keep our Night Sky?
Unlike other pollutions, Light Pollution is the cheapest to fix. Fortunately, it does not take much to protect our vanishing sky. Simple solutions such as changing the direction of our outdoor lighting downwards, as well as using lower wattage light bulbs can help drastically reduce Light Pollution and it's effects on Earth. Doing these simple things can help us see our vanishing night sky once again.
Light Pollution
What is it?

Light Pollution
How does this effect us?
Light Pollution is an unwanted consequence of outdoor lighting and includes effects such as
sky glow, light trespass, clutter, and glare.
Light Pollution's
Effect on Humans
Light pollution has consequences for human health. It can effect our
circadian rhythm
and our hormone
. Our night vision can also be severely impacted. Glare on the eyes from excessive night lighting can cause
disability glare
Disability Glare
Disability glare is glare from roadway lighting that is so bright it causes us to avert our eyes. Older Drivers are particularly vulnerable to disability glare. Disability Glare Reduces:
Ability to distinguish contrast
Color perception
The aging eye is also susceptible to eyestrain and loss of night vision
The Circadian Rhythm
Our over exposure of artificial light causes the circadian rhythm to be thrown off. The circadian rhythm is the 24-hour cycle that our bodies run on and what keeps us content and healthy. Studies show that disruption of this cycle can lead to insomnia, depression, cancer, and cardiovascular disease.
A hormone called Melatonin is what maintains a natural sleeping rhythm. Artificial light affects this rhythm, decreasing the levels of melatonin in your body. Melatonin is only produced in the darkness. Even a little exposure to artificial light will disturb the melatonin production
Photo taken by Photographer Jim Richardson over Chicago, Illinois.
Photo taken by Photographer Jim Richardson, taken of New York City's Skyline.
Another consequence of light pollution would be the impact it has on our night sky. Because of improper lighting the clarity of our night sky is becoming more and more obscure and dim from our view.
These astonishing pictures taken by Todd Carlson in Goodwood, Ontario shows the high effect
light pollution has on our night sky. The first picture shown is during a blackout in
Goodwood, Ontario on August 14, 2003. The next picture is a picture of the same exact place
and time of day but was taken a day after once the power was restored.
Light Pollution's Effect on Wildlife
The effects of light pollution on plants and animals in the environment are numerous and are becoming more known. In general, the most common action is that light pollution alters and interferes with the timing of necessary biological activities. But for nocturnal species that begin their daily activities at sundown, our artificial lights at night seriously constrain their lives, exposing them to predators and reducing the time they have to find food, shelter, or mate and reproduce.
Our Vanishing Sky by Astrogirlwest
URL LINK ht t p : / / w w w . y o u t u b e . c o m / w a t c h ? v = J J 9 a L i y 9 u c Q
Sky Glow
Sea Turtle Hatchlings
Hatchlings that crawl toward artificial light sources are following the same instinctive response that leads them seaward on naturally lighted beaches. The apparent brightness and glare of artificial lighting is what often leads hatchlings astray. To a hatchling on a beach, an artificial light source appears bright because it is relatively close by, yet it is not intense enough to brighten the sky and landscape. The resulting glare makes the direction of the artificial source appear overwhelmingly bright-so much brighter than the other directions that hatchlings will ignore other visual cues and move toward the artificial light no matter where it is relative to the sea.
Tracks of disoriented loggerhead (Caretta caretta) hatchlings, Melbourne Beach, Florida.
Photograph by Blair E. Witherington.
Light Trespass
Skyglow is the illumination of the night sky or parts of it. The most common cause of skyglow is artificial light that emits light pollution, which accumulates into a vast glow that can be seen from miles away and from high in the sky. Skyglow from artificial lights is common throughout the world and can be observed over most cities and towns as a glowing dome of the populated area.
Light trespass occurs when very bright lighting is cast where it is not wanted. Light trespass is somewhat subjective because it is difficult to define when, where, and how much light is unwanted. An example of light trespass is when light from a streetlight or floodlight enters a window and illuminates an indoor area.
Light clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertising surrounds the roadways
Glare is a visual sensation caused by excessive and uncontrolled brightness. It can be disabling or simply uncomfortable. It is subjective, and sensitivity to glare can vary widely. Older people are usually more sensitive to glare due to the aging characteristics of the eye.

This Youtube video by Astrogirlwest shows the dangerous effects of Light Pollution on our environment.
Disoriented Loggerhead
Data courtesy Marc Imhoff of NASA GSFC and Christopher Elvidge of NOAA NGDC. Image by Craig Mayhew and Robert Simmon, NASA GSFC
Work's Cited Page
Speech 101-705
Professor Marmer
Asma Naeem
Ashley Liggins

Astrogirlwest. (2010, October 7)
Our Vanishing Sky [Video file]. Retrieved from
Full transcript