[Darksky]Living in the Light continued, [OL-Forum] Digest Number 343 (fwd)
Jan Hollan
Tue, 18 Dec 2001 08:56:17 +0100 (CET)
---------- Forwarded message ----------
Date: 26 Nov 2001 12:52:46 -0000
From: OutdoorLighting-ForumAyahoogroups...
To: OutdoorLighting-ForumAyahoogroups...
Subject: [OL-Forum] Digest Number 343
OutdoorLighting-Forum
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There are 4 messages in this issue.
Topics in this digest:
1. Cancer risk linked to night shifts
From: "David Oesper" <DaveOesperAaol...>
2. Disinformation rears ugly head
From: kgflemingAatt...
3. Re: What's A Homeowner To Do?
From: John Gilkison <jgilkisoAzianet...>
4. Re: Living In The Light III
From: John Gilkison <jgilkisoAzianet...>
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Message: 1
Date: Mon, 26 Nov 2001 00:20:24 -0000
From: "David Oesper" <DaveOesperAaol...>
Subject: Cancer risk linked to night shifts
There is a short article in the November 17, 2001 issue of Science
News titled "Cancer risk linked to night shifts" on p. 317. While
the article is not available online, references and sources for the
article can be found at <http://www.sciencenews.org/20011117/
note16ref.asp>. In the last paragraph of the article, it says, "The
two studies point out 'an urgent need' to further explore links
between light at night and cancer, argues Johnni Hansen of the Danish
Cancer Society in Copenhagen."
David Oesper
Ames, Iowa
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Message: 2
Date: Mon, 26 Nov 2001 04:01:34 +0000
From: kgflemingAatt...
Subject: Disinformation rears ugly head
Here's an article that starts out promising then turns
to some classic red herrings. The gentleman from
Columbia needs to brush up on how to talk to the media.
http://www.wired.com/news/technology/0,1282,48593,00.html
"Because of the growing glow from street lights,
illuminated signs, and brightly lit homes and offices,
city dwellers are losing the night's deep velvet skies.
The Milky Way is dimming, and even last Sunday's Leonid
meteor storm was, for many of us, washed-out by light
pollution.
Pierantonio Cinzano and Fabio Falchi of Italy's
University of Padova estimate that two-thirds of the
world population, including 99 percent of the people in
the continental United States and Europe, live under
light-polluted skies.
Their study, co-authored with a Boulder, Colorado,
researcher, found that more than two-thirds of Americans
and more than one-half of Europeans no longer can view
the Milky Way from where they live...
And later --
"Opponents view IDA's lobbying efforts as an attempt by
a special interest group pressuring governments to levy
additional costs on everyone -- replacement lighting
fixtures aren't free -- for the benefit of only a few
hardcore astronomers. And, especially in the West, IDA's
approach may begin to butt heads with the growing
property rights movement.
"One day we'll get higher tax bills and we'll wonder
what happened," says Sonia Arrison, director of
technology policy at the free-market Pacific Research
Institute. "It's all because some astronomers lobbied
some people on city council."
"If these guys get any political support for what they
want to do, it's only because nobody else is watching.
The public isn't paying attention," Arrison says. "Right
now, especially after the terrorist attacks, people want
their streets to be bright at night."
Joe Patterson, a professor of astronomy at Columbia
University, seems almost resigned to Earth's ever-
lightening skies.
"The lights are primarily for advertising and safety.
The interests of humanity are enormously more powerful
than the interests of astronomers," Patterson
says. "Astronomers dislike all types of light, but
there's not much we can do about it..."
Kevin
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Subject: Nelpag digest, Vol 1 #167 - 1 msg
Date: Sat, 24 Nov 2001 12:01:05 -0500
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Today's Topics:
1. Didn't There Used to Be Stars? (Eric S. Johansson)
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Message: 1
Date: Fri, 23 Nov 2001 19:49:48 -0500
To: nelpagAharvee....ma.us
From: "Eric S. Johansson" <esjAharvee....ma.us>
Subject: [Nelpag]
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Message: 3
Date: (unknown)
From: John Gilkison <jgilkisoAzianet...>
Subject: Re: What's A Homeowner To Do?
WHAT'S A HOMEOWNER TO DO ?
Since outdoor lighting steals the vision of the stars from our skies, what
are we to do? Does this mean that while living in a society with the
technological gift of electric lighting that we must forsake the use of
lighting at night? It does not, but some of the ways we have grown accustom
to employing outdoor lighting need to change radically.
Recently I was having lunch with a friend who is campaigning to reduce
light pollution, (as am I) and he told me one of his first goals was to
convince people he wasn't trying to take away their lights. I told him "but
Bill, I
am", to which he said "shhhh ".
I am going to go out on a limb here and say something most people in the
light pollution battle would seldom care to admit publically, and that is
from my perspective up to about 90% of all outdoor lighting is not needed.
Not only is it not needed, a giant waste of energy, but much of it is
counter productive.
Now I will admit that this is not a good way to approach the issue right
off, and if you do you may loose much of your effectiveness. In other words,
if you need to educate people from A to Z, you need to show them the way
through a good part of the alphabet before you get to the letter Z.
For lighting illuminate anything it has to be reflected off of the subject
matter at hand first, then enter the eye, This means that lighting that is
not Full Cut Off (FCO) lighting to below the horizontal plane is wasting
light as glare directly to the eye, as waste light too far from the fixture
to be useful, or to the sky as light pollution. Secondly, the human eye is
a very sensitive and adaptable detector of light, so in actuality very
little light is really needed for effective illumination at night.
I don't want to get too bogged down in the science of FCO lighting, as it
is being well covered by many others in their advocacy for sane lighting now
days. A good rule of thumb to remember is you should never see the light
coming directly out of a fixture from beyond four mounting heights. So your
six foot high porch light really should not be illuminating anything beyond
24 feet, for example.
An important message I think need to be addressed more often is just how
little light we need to see at night. Our eyes are built to see by star
light. In fact our dark adapted vision is shifted slightly towards the blue
end of the spectrum or this reason. Full Moon light which seems to
illuminate the whole expanse of the countryside at night is in fact over one
hundred times less bright then the
light under a street light. So for general use you really don't need more
then one footcandle of illumination.
A good way to figure this without a meter is multiply the square of the
mounting height by twelve and that is all the lumens you really need for
that mounting height. So for a six foot mounting height 36 x 12 = 432 lumens. A
7,000 lumens output barn bomb at a 10 foot mounting height is just plain crazy.
For socket down mounting applications a small flood light (50 watts or
less)can be a good substitute for full cut lighting in the absence of a FCO
fixture. Another way to install FCO lighting around your house is to build
flood light fixtures into your soffits.
A very important concept here is that you do not need dusk to dawn
lighting. A light that is on when you are not in the area is of no real
value to you. Most break ins take place during the day, and crime and
justice studies have not been able to make any real correlation between
crime and lighting.
What you really need lighting at night for is safety, so you don't injure
yourself, and so you can find your way. Common sense in outdoor lighting
begins with the individual at home first, then radiates through our society.
Most of our outdoor lighting habits are just thoughtlessly copied
misinformation.
*
John Gilkison
President, National
Public Observatory
jgilkisoAzianet...
www.astronomy-national-
public-observatory.org
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Message: 4
Date: (unknown)
From: John Gilkison <jgilkisoAzianet...>
Subject: Re: Living In The Light III
IMPROVING CITY LIGHTING!
By this point you may be saying "this is all well and good for a homeowner,
but it just isn't practical for a city". All the general principles still
apply, as well as a few we haven't mentioned yet. Our cities are overlit,
growing more so by the year, and yet we can't see well at night on the streets.
When I say up to 90% of outdoor lighting can not be justified, this
especially applies to cities. The problem is the result of something called
signal to noise ratios in engineering. Have you ever been booming doing the
road at 70 MPH listening to the radio only to exit, but in coming to a stop
find you have to turn the volume down. That is an example of a signal to
noise ratio problem in daily life.
This is what we are doing in our cities with light instead of sound. We
utilize so much lighting at night in our cities that it all has become
counter productive, and in order to compete, lighting has to become ever
brighter. We have literally created a spiraling impossibility with
lighting, where some marketers have ratcheted up light levels to a hundred
foot candles or more, just to get noticed.
It is time to ratchet down the light levels for
the safety of our citizens. It has now become common for light levels on the
streets to be so high, people can drive around without their headlights, or
worse do not know they don't have them on.. This brings up a good question.
Why do we have headlights on cars, if we are going to provide so much
lighting that they are not needed?
While a good case can be made for lighting arterial highways, way too much
emphasis has been place on uniformity in lighting. What is the point of
lighting intersections or other significant junctions when in lighting the
whole stretch of a highway nothing stands out in the surrounding any longer?
No real case can be made for lighting residential areas, as homeowners
should provide their own lighting for their property if they want it. How
did providing public lighting for private property, even if the citizen does
not want it, become a given, anyway? With FCO lighting at intersections for
safety, and only low lumens output FCO lighting allowed in residential areas
citizens would be able to enjoy a view of the night sky again.
A friend of mine who works for the DOT in another state told me a story
about lighting engineers complaining about how they have to increase the
light output of street lighting to compete with business lighting. The real
answer here is for the authorities to control the amount of light used by
businesses. General use areas like parking lots only need about one
footcandle and these levels should not be allowed to be ratcheted up. There
is no good reason for empty parking lots to be lit at 3:00 AM long after
closing.
Bi-level ballasting and photo/timer controls could go a long way towards
reducing all the unnecessary lighting we see in cities late at night
illuminating empty spaces. A few lights could be left on so security patrols
could monitor activity. Only in America, the land of $1.00 a gallon gasoline
and 10 cents a KWH electricity do we promote such a mindless profligate
waste of energy.
All outdoor lighting should be Full Cut Off, and of the appropriate light
output for the task at hand. When the lighting is not needed it can and
should be turned off. Just using FCO lighting allows for a 30% downsizing of
lighting fixtures by the redirection of light that is normally thrown away
in partially shielded light.
Once we stop lighting everywhere, we will see what we do light better. The
eye sees by contrast, and uniformity in lighting really shouldn't be a holy
grail in outdoor lighting. With a better quality of outdoor lighting we can
have safety, and the stars back in our lives too, at a reduced cost to us all.
*
John Gilkison
President, National
Public Observatory
jgilkisoAzianet...
www.astronomy-national-
public-observatory.org
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