Where has the night sky gone, and why should we care?
It happened slowly at first several decades ago, a process that was hardly noticeable. A light here, a light there, burning their way into the dark nighttime realm, helping us see in the darkness when we're all in our beds fast sleep. The process continued as it continues today, with little thought ever given to what we are stealing away. Our intentions are good but our methods need adjustment, and they need to be adjusted immediately. In fact, our methods should have been adjusted years ago, but nearly everyone has resisted, perhaps due to a profound lack of awareness.
As a consequence, the stars in the nighttime sky began to disappear. One here, one there, a hardly noticeable process began to progress slowly across the nighttime sky, beginning at first over large metropolitan areas then spread slowly to nearly every corner that civilized people reside. Astronomers began to complain as faint celestial objects billions of miles away began to disappear from their telescopes. The public and officials laughed their cries off, not considering at all what was being lost by this process. To correct the problem would hurt business and we certainly could never do that! In fact, correcting the problem would help business more than most people presently realize.
The night is being turned into day in most areas by poorly designed and improperly aimed unshielded outdoor lighting. It lights our roads and highways from dusk to dawn, whether vehicles are traveling or not. It lights our parking lots and building exteriors whether employees or patrons are present. We think bright light frightens away crime, but no study has yet proven this to be true. The best assumption that can be made by these studies is people merely have a feeling of safety. Crime continues to rage on in large cities that never seem to sleep while remaining bathed in a nocturnal glow. The glow comes from bad lighting applied by designers who don't understand the four elementary concepts. Shield it, point it down, don't use more than you need, and turn it off when you are done and not there.
Architects and city planners light building exteriors, bridge structures and support cables around the world more and more with reckless abandon, not considering what harm they perform to surrounding areas. We need those lights on to attract attention, to say see here, look what we've done! Most of the world doesn't care, for they are busy fast asleep in their beds. The lights diligently continue to burn in unshielded fixtures, broadcasting glare in the air, taxing natural resources, creating the needless additional pollution of water, earth, and air. Most tragic of all is their skyglow erases the night stars by this process. Two generations now live on our world never having seen our address in the Universe. The Milky Way overhead is where we reside in the heavens but many only see it in candy aisles today.
Impact studies are performed on the environment before development occurs by very bright people who consider nearly every aspect. One subject seems to be rarely if ever considered, however. How will that string or cluster of lights burning unshielded affect the environment around them? Oh they are only trees, or squirrels and birds in the trees, or maybe a fox or a deer here and there. What will they care if a light burns all night long? It may have been too long since these evaluators opened their biology books and read the chapter on photosynthesis and plant cycles. It states that the process of every green plant needs a measure of darkness to properly complete its circadian rhythm. It says that the waning sunlight of seasonal change causes some plants to go dormant and drop their leaves. For countless eons this process continued on schedule without error until merely a few decades ago.
In the 1970s, the US Department of Agriculture noticed that dusk to dawn lighting from a high-pressure sodium lamp was affecting young sycamore trees. It confused their seasonal rhythms causing sap to remain in the leaves and branches too long. They dropped their leaves too late, frost came and the cold of winter soon followed. The following spring many of the year old saplings perished. What be this force behind the mystery killing these trees? Dust to dawn lighting is beneficial, we need it to see in the dark while most of the world is busy fast asleep in their beds.
Has anyone ever considered why that robin is chirping away in the tree at 2:30 AM? He thinks dawn is breaking, excited about contemplating the meal from his next juicy worm. The dawn doesn't come for hours, yet that unshielded light burns away in the distance confusing his little bird brain. Oh it's just a bird, who cares? We need that light burning all night so we can see in the darkness while the world is busy fast asleep in their beds.
On a beach far away a hoard of young sea turtles hatch from their eggs and trod into their fresh new world. They enthusiastically scurry across highways and parking lots, instead of into the ocean where they belong. The bioluminescence of the sea is obscured by an unshielded streetlight or a gas station canopy beaconing another customer who might just pass by unless they are dazzled by ten times or more the amount of light that is needed to see. The next day, hundreds if not thousands of tiny turtles lay dead from exhaustion and dehydration, only to be picked up by birds or baked dry by the sun. They are only turtles, who cares? We need that bright unshielded light so people can see in the dark while they are busy fast asleep in their beds.
Please view the photo in the following document found on the Web:
The Defense Meteorological Satellite Program (DMSP) took the photo appearing on the "Introduction to the Issues of Light Pollution" in 1994 for a biomass study performed by the National Oceanic and Atmospheric Administration (NOAA). As you can see, this is a photo of the United States at night indicating all of the wasted light shining into the sky. Outdoor lighting has advanced in tremendous proportions since 1994 when this study was done. I contacted NOAA about two months ago hoping they had more recent photos available, but this part of the biomass program ended in early 1995 and the NOAA has no plans at the moment to repeat the study.
Light Pollution in the simplest terms is the result of too much wasted light. It has been estimated to cost the United States alone well over a billion dollars per year for the electricity generated to send light into the sky and across property lines where it serves no benefit. Wasted light sent to the sky needlessly is seriously affecting scientific research today for professional and amateur astronomers along with some NASA research, too. Astronauts have complained about this problem for years. Astronomical observatories are closing down because they can no longer see enough celestial objects to justify continuing their funding or research. A great heritage is being lost in the process, the fragile dark night sky filled with stars overhead.
The waste from poorly applied lighting affects everyone in our society including individuals, businesses and municipalities. It does not matter whether they appreciate watching stars or not. Light Pollution costs us more in taxes, operating expenses for businesses, and in the price of all goods that we purchase. You can easily see this waste for yourself each time the clouds overhead glow an eerie pink in the night. When that light outside finally shines one too many times through your bedroom window, you may think of this paper, and it might compel you to write to your government representative requesting comprehensive Light Pollution reform.
A very interesting phenomenon occurs with artificial outdoor lighting due to the way the human eye reacts in dark surrounds of the nighttime environment. Oddly, most people think the more light they apply to an area, the safer and better it will be. This could not be farther from the truth, because if too much light is applied to one area, this makes another area near by that previously had perfectly adequate lighting appear to be too dark. Poorly designed fixtures that spill glare sideways and upwards compound this problem, severely affecting visual acuity in a negative manner, which reduces not increases public safety.
This happens because of the way our eyes work in the darkness. When in darker surroundings, the iris in our eye opens letting more light enter so we can see properly. When an area has too much illumination or glare this causes the iris to close, which in turn, prevents the excess light from entering the eye. Our societies need outdoor lighting to provide safer conditions for citizens and building security. Our current mindset must be modified when achieving this goal, however, because we are wasting resources and destroying the night sky in the process.
We need more quality lighting and not a greater quantity of lighting. More often than not, the less light that gets applied to one area makes less light necessary in adjacent areas, allowing us to see more efficiently in outdoor surroundings. This practice reduces the contrast between bright and dark areas, improving our visual acuity in the process. The Illuminating Engineering Society recently lowered most of their recommended outdoor illumination levels in an effort to make our societies safer at night and improve visual performance. This will also help to reduce the tax on the world's natural resources and save an enormous amount of money at the same time.
Glare is defined as a visible source of illumination that causes a deterioration in visual performance. Glare makes the iris of our eyes close, which makes everything that is illuminated appear to be darker than it should be. Light fixtures that create glare require higher wattage bulbs to overcome this phenomenon, which cost more money to use. This in turn results in greater emissions cast into the atmosphere and provides a larger tax on dwindling fossil fuel reserves. Lights that shine glare are counterproductive, bad for the environment, and wasteful.
We use lampshades in our homes to shield the bulbs' glare from our eyes so we can see everything better. For some strange reason, when bringing artificial lighting outdoors into the night this wisdom is quickly forgotten. Full cutoff optics (FCO) and shielded light fixtures are like the lampshades used in our homes, but they are used for the outdoors instead. FCO fixtures prevent light from being spilled into the sky and across property lines. They do not shine light into windows reducing privacy and inhibiting sound sleep because they put nearly all of the illumination where it belongs, mainly on the ground below.
Glare is considerably reduced by FCO lights and nighttime vision is enhanced in the process. Full cutoff lighting often allows using lower wattage bulbs because what would be wasted to the sky and across property lines is directed downward instead of outward in all directions. Our communities will be far safer to travel in and more pleasing to the eye after glare is removed from the equation. Business will benefit through lower operating costs and increased off-hours security when they finally learn to use infrared proximity sensors for properly shielded and aimed security lighting instead of burning those bulbs all through the night.
More is not better when we speak of light in the night. The view of the stars will return overhead where they belong when we finally learn to shield outdoor lighting, aim it downward to the ground where it is needed, use only as much as needed for the task, and turn it off when it is no longer needed. The reality is, an outdoor light is only needed when a human is there at the time and needs to see where they are going. Burning a light after they are gone when nobody is there to benefit is simply a waste of both money and resources. When our societies finally learn this concept, the pristine ebony blanket studded with tiny points of light coming from countless miles away will return again where they belong, where they've always been since the dawn of time itself, and where they should remain for countless generations to come.
Please do more research on Light Pollution. The International Dark-Sky Association is an excellent place to begin. Their website has over 150 information sheets available relating to Light Pollution and a number of additional resources to explore. Please consider becoming a member and take an active part in restoring the view of our night sky around the entire world.
International Dark-Sky Association, Inc.
Bob Gent -- IDA Public Relations Officer
Dr. David Crawford
You may wish to review information found at my Light Pollution Awareness Website. A link to my LiteLynx list is available that gives access to over 250 different sites on the Internet that offer more information about lighting and Light Pollution. I have researched this subject for some time and the LiteLynx is a partial listing of that research along with the bibliography for this paper that I am submitting. My website is available on the Internet at:
Back to top of the page
Back to the List of Participants with Research Papers
Back to Global Dialogue
Back to the Portal of the Global Community organization