Category Archives: Light Pollution
After a few months of inactivity I’ve developed an idea that will keep me busy blogging. It’s been cloudy for so much of the summer so I haven’t been able to do much observing. My attention, therefore, has turned to other activities related to astronomy that I can pursue when the weather is not ideal for observing. If you’ve read any of my previous articles on this site you’ve probably read about light pollution. Maybe you’ve heard of it elsewhere or perhaps you’ve never even considered the possibility of light being a pollutant. While electric lighting is a marvel of the industrial age and a wonderful aide to modern life it also, like many good things, has a darker side.
From the beginning of life on Earth approximately 4 billion years ago all of Earth’s creature, including humans, have lived in an unending cycle of light and dark. Bright sun-drenched days give way to the darkness of night and the majesty of a star-strewn sky with its backbone the Milky Way arching across from horizon to horizon. Life has evolved according to that cycle and it has flourished. It wasn’t until just over 100 years ago that we began introducing large quantities of artificial light into the environment. This artificial light disrupts the light-dark cycle (also known as the circadian clock) that life has depended on for billions of years. It has endangered species like insects, turtle, hundreds of species of birds, and all manner of nocturnal creatures. Artificial light is also a known contributor to many human diseases such as obesity, insomnia, diabetes, and hormonal cancers. Besides the biological effects of artificial light, it is also a massive waste of energy. Every year in the United States alone, poorly designed or over-used light that shines up into the sky wastes $2.2 billion!
Last, but certainly not least, artificial light has destroyed the night sky that humans have loved for thousands of years. When the lights from un-shielded fixtures shine up into the sky the light scatters when it hits particles in the air. The result is called skyglow. You can clearly see the effects of skyglow when you look towards a city or town at night from a distance. The yellow, orange, or pink glow in the sky is the sum of all the light from all the street lights, parking lot lights, stadium lights, residential lights, etc…and their light scattered in the air. The dome of light obliterates all but the brightest stars and the Milky Way is a thing of the past. Depending on the size of the city, skyglow is noticeable from as far as 100 miles away as a dome on the horizon.
Light pollution has severe negative consequences on my pursuit of my hobby of astronomy as I have to drive considerably far from my home to view under dark enough skies. I currently drive 33 miles from my home in north Baltimore to reach my observing site in Fawn Grove, PA and even there the effects of light pollution are quite pronounced and the Milky Way is barely visible on clear, moonless nights. To reach a location almost totally unaffected by light pollution I’d have to drive five hours north to Cherry Springs State Park near Coudersport, PA.
What I’ve decided to do over the next couple months (or however long it takes) is to compile a photo essay of sorts that chronicles the effects of light pollution throughout the Maryland and Pennsylvania area. My goal is to photograph constellations, horizons, skylines, and light fixtures everywhere to make known to my readers the harmful effects light pollution has on the night sky and astronomy. I will visit many locations throughout Maryland from the Inner Harbor in Baltimore, to a swamp on Maryland’s Eastern Shore, to rural York County, PA, an international dark sky park, and many places in between. I hope that this project will open some eyes and convince people of the reality of light pollution and the truth that it is something that we CAN fix.
In the United States today, eight out of ten people will never see the Milky Way in their lifetime because of light pollution. It doesn’t have to be that way though. Through public education and teamwork with local governments we can reverse the harmful effects of light pollution and preserve the night sky and its splendor for future generations.
Spring is finally in full swing and if you’re like me observing season is about to kick off again. I hate observing in the cold so when April rolls around it’s usually an indicator that better nights are coming…unless you live on the East Coast where it’s been unseasonably cold and cloudy for the last month. April is also exciting because it is Global Astronomy Month. Each year since 2009 Astronomer Without Borders has designated April as Global Astronomy Month to raise awareness for the study of astronomy both professionally and amateur. In my opinion, the biggest part of GAM is International Dark Sky Week. Beginning tomorrow April 5 and continuing through April 11, Astronomers Without Borders and the International Dark Sky Association are teaming up to raise awareness of the issue of light pollution. If you’ve read this blog before you’re probably familiar with the light pollution as I write about it quite frequently.
Because of light pollution, the artificial brightening of the night sky, less than a third of Earth’s population lives under natural, starry skies. Fifty percent of Americans and 75% of Europeans have to travel at least an hour from their homes to see a natural star-filled sky unaffected by light pollution. From my home in Maryland I have to travel 4.5 hours to reach the only truly dark sky spot around, Cherry Springs State Park in Potter County, Pennsylvania. I am willing to make this pilgrimage once or twice a year but there should be somewhere closer to observe from that has a quality dark sky. The reality is, however, that these places are slowly dwindling in number. Artificial light, the scourge of the night sky, is slowly but surely conquering the beauty of the natural night sky.
Light pollution comes from poorly designed artificial light sources we use at night. Most of these light sources are from street lights that are unshielded so that light escapes upwards into the air which causes the light particles to scatter and create that familiar sky glow effect. Other problems are that we often use wattage that is too high for the task we’re trying to accomplish. If you’re using too bright of a light the light actually reflects off the ground and bounces back up into the sky to contribute to the sky glow.
You’ve also probably noticed the annoying glare that unshielded lights cause while driving. Glare comes from the bright ball of light generated by a typical drop lens or acorn style street light. See the example below for a typical “glare bomb”. The glare created by these lights can not only be annoying while driving, they can also be dangerous for people with poorer eyesight such as seniors or people with sight disorders. They are also so bright that they can mask important things like road signs and signals along with pedestrians and animals in the road.
Light trespass is also an result of poor lighting design. Light trespass occurs when a light from a neighbor or nearby building shines, or trespasses, on your property. For example, a stray light that shines into your bedroom at night that causes you to get inadequate sleep. To make a long story short, the lighting used should fit the requirements of the task it is trying to accomplish, no more, no less. We all agree that artificial light helps our society. But since when did extravagant over illumination become acceptable. Not only does light pollution affect the night sky, it is also a HUGE money waster! Every year over-illumination in the United States alone costs the same as approximately 2 billion barrels of petroleum and consumes unnecessary fossil fuels that are not replenish-able. Imagine how the cost of a gallon of gas could decrease if we didn’t over-illuminate our homes, businesses, and roads!
Fortunately, the solution for light pollution is relatively simple. Taking the time to assess your lighting needs and using the proper wattage and shielded fixtures will go a long way in reducing the amount of artificial light we send up into the night sky. Using shielded fixtures ensures that the light only goes where it is needed: the ground. This also allows for a lower watt bulb to be used and that in turn reduces the amount of light reflected back off the ground. Motion sensor are also useful to turn the light on only when there is movement.
Talking to neighbors about their lighting in a polite but concerned way is a great way to introduce the topic to them. Writing to legislators can be effective as well. There have been a number of municipalities that have incorporated lighting regulations into state, county, or local code in recent years. There is a bill in Maryland that is currently in the General Assembly that would require all new light fixtures purchased by state agencies to be fully shielded. The biggest hurdle we have to overcome is simply making people aware that there is a problem. Many people don’t even think about the light they see at night or how their lights are contributing to the pinkish glow we know all too well. In order to reverse the effects of light pollution we must use word of mouth to let people know that light pollution is real and it is diminishing the beauty of our night sky and wasting money in the process.
If you’d like to learn more about the issue of light pollution please read some of the other posts I’ve written on this blog and visit the International Dark Sky Association’s website www.darksky.org. Together we can put a cap on light pollution and restore the beauty of a star-filled sky!
I love hearing about light pollution in the news and media, especially when the stories are about people, towns, or governments taking action. That’s why when I read an article on guardian.co.uk about a new light pollution law in France I nearly did my version of the Ray Lewis dance! The new law is an attempt to both curb several aspects of light pollution. France’s Minister for Ecology, Sustainable Development and Energy, Delphine Batho, announced the new law yesterday directed towards lighting on non-residential buildings across the country. The new law will make it obligatory for shops and commercial buildings in France to shut off their interior, window, and exterior lighting at night.
The main aspects of the new law are as follows:
- Interior lighting in office buildings must be switched off one hour after the staff leaves the building
- Exterior lighting used for illuminating building facades may be turned on one hour before sunset but must be switched off by 1 a.m.
- Window lighting in commercial buildings must be switched off between 1 a.m. and 7 a.m.
Minister Batho announced the law hopeful for France’s future as a global leader in the fight against light pollution and all its negative effects. According to the non-governmental organization the Agence de l’environnement et de la maîtrise de l’énergie(ADEME), the new law will help France save two terrawatthours of energy each year (1 terrawatt is 1 million megawatts) which is enough to power 750,000 homes in France every year. These energy savings results in a reduction in France’s CO2 output by 250,000 tons each year.
As with almost every light pollution ordinance there are exceptions. Buildings that are tourist attractions year-round are exempt from the new law, as well as Christmas lights, and local holidays and festivals.
Minister Batho is hopeful that the new regulations will not only reduce France’s energy consumption, but also help preserve the nocturnal environment, limit health problems caused by excess light, and of course help improve the quality of the night sky. The law will go into effect on July 1, 2013 so if you’re an astronomer, professional or amateur, in France make sure you wait until after 1 a.m. to set up your telescope for the night! I can only hope this snowballs into bigger and better things for France and all of Europe in regards to fighting light pollution. Well done.Sources: Davies, Katie, The Guardian Online, http://www.guardian.co.uk/world/2013/jan/30/lights-out-france-shops-offices Myels, Robert, Digital Journal http://www.digitaljournal.com/article/342542 de la Baume, Maïa, New York Times http://www.nytimes.com/2013/01/31/world/europe/paris-lights-to-be-dimmed-to-save-energy.html?_r=0 Additional Resources: http://www.lampclick.com “Light Pollution: Effect on Humans and Energy Efficient Solutions“ Astronomers Without Borders Dark Skies Awareness Blog International Dark Sky Association