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International Dark-Sky Assocation
Light Pollution: How Seeing the Stars will
Save You Moneyand possibly save your life if
you are femaleDr. Harold Williams
Montgomery College Planetariumlocated at the Takoma Park/Silver Spring
Campus http://montgomerycollege.edu/Departmennts/planet
International Dark-Sky Assocation
What Is It?
• The Night Around Us.– Our Communities.
• The Night Above Us. Dark skies.
International Dark-Sky Assocation
The Bottom Line on “Why”• For a functional, comfortable, and
beautiful nighttime environment.
• For an environment friendly to:– humans, including the aging eye,– wildlife,– plants,– the night sky.
International Dark-Sky Assocation
Where to light and when?
• Only where it is needed.– Avoid obtrusive light.– No wasted light or energy.
• Only when needed.
International Dark-Sky Assocation
How much light?
• The myth of The More the Better.– Use IESNA or CIE recommended levels.
• Environmental lighting zones.– Consider the location where you are.
• Use good transition lighting.
International Dark-Sky Assocation
North America at Night
International Dark-Sky Assocation
Poor security lighting,using an old fashion 175 watt mercury fixture
International Dark-Sky Assocation
Almost a definition of light trespass,at an installation in San Francisco.
International Dark-Sky Assocation
Glare from a walkway light.
International Dark-Sky Assocation
Glare, luminance overload, bad transition lighting
International Dark-Sky Assocation
Why so much bad lighting ?
• Lack of awareness.– Even in the lighting community.– Builders, contractors, owners,
operators.– The public. Governmental staff.
• Apathy, or inertia.
International Dark-Sky Assocation
Keys to Quality Lighting
See the effect, not the source.Shine the light down.No glare!Light only where and when needed.Don’t over light.Use energy efficient sources.
International Dark-Sky Assocation
Use of a full cutoff fixture for a parking lot
International Dark-Sky Assocation
A good antique (or period lighting) fixture, full cutoff
International Dark-Sky Assocation
Here is another good example,using lighting fixtures with good control of the light output.
International Dark-Sky Assocation
So …• It works, right? It’s common sense.
• Use only good lighting!
• Let’s fix the bad stuff!
• Educate everyone; build allies.
Your Sixth Sense!
• Melanopsin
• Suprachiasmatic nucleus
• Pineal gland
• Melatonin
Melatonin C13H16N2O2
Eye
Some demographic evidence
• Artificial lighting in the industrialized world: circadian disruption and breast cancer by Richard G. Stevens in Cancer Causes Control (2006) 17:501–507
• LIGHT AT NIGHT CO-DISTRIBUTES WITH INCIDENT BREAST BUT NOT LUNG CANCER IN THE FEMALE POPULATION OF ISRAEL in Chronobiology International, 25(1): 65–81, (2008) by Itai Kloog, Abraham Haim, Richard G. Stevens, Micha Barchana, and Boris A. Port
International Dark-Sky Assocation
Some Other Issues
• Visibility• Safety and security• The aging and disabled eye• Human health, and animals and
plants.• Energy• We all win!
International Dark-Sky Assocation
IDA• The International Dark-Sky
Association
• Newsletter.• Information sheets. Images. Slides.• CD’s, videos, and so on.• Web site: www.darksky.org
• Join IDA ! We need you.
International Dark-Sky Assocation
IDA’s Goals
• To preserve and protect the nighttime environment and our heritage of dark-skies through quality outdoor lighting.
• Membership based. Over 10,000 members, from all the states and 70 other countries. 500 organizations.
International Dark-Sky Assocation
International Dark-Sky Association
• 3225 N First Avenue• Tucson AZ 85719 USA
• 520-293-3198 Fax: 520-293-3192
• [email protected]• www.darksky.org
