Download Light Pollution and the IES

The Observations of an Observer
The Ups and Downs of Lighting
Light Pollution
and the IES
“Sight Lighting?”
Dan Caton
Our shared interest
What you do
What I do
Another shared interest
What we will look at…



Why is the night sky of interest? Why do we
care?
Regional observatories
The light pollution issue—a brief primer and
personal observations
Why should we care about astronomy?
Some ‘practical’
reasons…
First, “look” at the
sun and its spots …
Our Sun: The Maunder Minimum
We need to study other solar type stars!
Deep Impact?
Are we alone in the galaxy?
• Most interesting
question science
can ask.
•We now have >100
extrasolar planets.
•We will image
Earth-size planets
within a few
decades.
You are here
100,000 hobbyists
Everyman…
Just as important
ASU’s Dark Sky Observatory
18-inch Telescope’s dome (1981)
18-inch
Telescope
Instrumentation
(little visual use)
Spectrograph
CCD camera
32-inch Telescope’s Dome and Cline Visitor Center
32-inch Telescope
CCD camera
Fork mount
Warm
room
In the Warm Room…
Typical observing …
The Horsehead Nebula
M13 Globular Cluster
Other NC Observatories


Three College
Observatory near
Greensboro
(UNCG, NCA&T,
and Guilford College)
Cline Observatory

Guilford
Technical
Community
College
(Greensboro)
UNC-CH


Morehead
Observatory, on
campus
SOAR telescope
in Chile
Light Pollution: the loss of the night sky
Light Pollution and the IES
The basic problem: Sky Glow




Light from fixtures reflects
off particles in the sky—”Sky
Glow.”
Large cities visible from tens
of miles.
The stars are not brighter in
the country—the sky is darker!
Reminds me of …
Thursday’s lunar eclipse
• An email exchange led to the comment …
• …”The stars seemed slightly brighter as the moon dimmed”
Our Global Problem
Light “Made in the USA”
Closer to home
You are here!
Boone,NC 35 years ago…
… today
Even at Kitt Peak
Charlotte…
Courtesy Spencer Rackley
Light Pollution Causes






Poor fixture design
Lack of shielding
Over-lighting
Poor installation
Market pressure
Let’s look at a few
specific problems
Floodlights



Almost horizontal
No shielding
At night …
Typical fast-food lighting
Better: Full Cut Off
Even Better!
• Van Gogh’s Café
Terrace at Night,1888
• Experience at Tweetsie.
• Result from California
study: reduce glare and
you can reduce the
overall lighting level
Roadway lighting-overhead glare
Majority of the”light budget”?
Sag-Lens Cobra heads


Glaring to driver
Light polluting
Better, FCO Fixtures





No light above horizon
Non-glaring to drivers,
too!
May require more poles
per mile—but could we
get the DOT to specify
FCO?
CP&L
And at night …
Car Sales Lots



Often grossly overlit
This one at 60-110 Fc
on lot, 65 on road
Can be done nicely…
… like this (Tampa)
Wall Packs



One of the worst
fixtures for pollution as
well as glare (or even
for its intended
purpose!)
Are available in FCO
What is the point of
these? 
I will give you architecture, but…
Why shown in day?
Ever notice?
Bad area/security lighting
Solution: put a lid on it!
New
GE SkyGard
shown here.
Guaranteed
to 100
mph, tested to 120
Modern Gas Station Canopies
This about 85 fc – several times IES RP
This “1973” shot impossible today!
“Space Jam”
Real sports lighting


Often done poorly
with lots of light
pollution and light
trespass.
Can be done well as
shown here, using
fixtures like Musco’s
shown here
Let’s hope it does not come to this!
How the you can help





Support the development of lighting
ordinances in your region.
Embrace the new ideology at the IES and the
emerging National Outdoor Lighting Code
Work to increase the membership of IES so
there are more designers and designed jobs!
Tell us IDA people what we can do to bring
about change—you know the business!
Join the IDA and learn about the dark sky
movement. (I joined the IES!)
Summarizing




Light pollution almost always caused by luminaires and
techniques that do not do their task well.
We can all work toward better lighting and (thus)
darker, starry skies.
Thank you for your time and attention
www.darksky.org and www.ncdarksky.org
[email protected]
www.dan.caton.name