50 ASTRONOMY • JUNE 2015
were 48 percent more attracted to LED
lamps, regardless of bulb color, than they
were to high-pressure sodium bulbs. They
concluded that the new technology will
create a “white-light night” that increases
the ecological impact of light pollution.
And humans aren’t immune either.
Breast cancer studies have found that
tumor growth accelerates when artificial
light disrupts the circadian clocks of our
24-hour day and night cycle. That process
controls as much as 15 percent of human
genes, which leads researchers to suspect
other ill effects from photons falling on
human retinas at night. A report put out by
the American Medical Association even
recommends reducing light pollution, lim-
iting shift work, and avoiding excessive
nighttime exposure to electronic media.
The psychological impact is harder to
quantify. Scientists can’t put numbers on
what happens when millions of children
are raised in interconnecting light bubbles
with little reason to look up. The First World
Atlas of the Artificial Night Sky Brightness in
2001 showed two-thirds of Americans and
half of Europeans can no longer see the
Milky Way. In fact, after the 1994 North-
ridge earthquake knocked out power in
Los Angeles, many residents called emer-
gency lines to report a “giant, silvery
cloud” in the night sky.
The dark-sky gospel
James Lowenthal is a self-described
global warming evangelist. He’s also an
astronomy professor at Smith College in
Massachusetts, where many residents hold
similar environmental views.
One night, Lowenthal was riding his
bike home when the glaring lights of new
housing at a recently redeveloped psychiat-
ric hospital site caught his eye.
“I was confident because of the good
lighting ordinance I had helped pass,
any new development would comply,”
Lowenthal says. That was not the case.
He took photos of the noncompliant
lights and showed them to the city coun-
cil. His images drew gasps from the
elected officials.
He discovered the developers had told
city planners they wanted to give their
buildings a “village feel” and gained
approval to install acorn-style streetlamps
for acres and acres. When confronted with
the illegality of their lights, the developers
pointed out that the manufacturer had
stamped “dark-sky rated” on the product.
“It’s definitely not full-cutoff,” he says.
“It doesn’t satisfy any of the requirements
of the board’s own code, but because it
said ‘dark-sky rated,’ they approved it.”
“Every planning board in the country
must be dealing with this,” Lowenthal
says. “They’re overworked. It’s very easy
for things to slip through the cracks.”The problem has gotten worse for advo-
cates. Northampton appointed an energy
officer to monitor efficiency, and he’s push-
ing for LED streetlights to be installed
around town. The 2006 lighting code says
nothing about the new technology.
Lowenthal decided to fight for changes
to the code he helped pass. But his fight has
been acrimonious in the small town. He’s
met resistance while pointing to research
that shows excess lighting can negatively
impact human health and disturb wildlife
while having little effect on public safety.
The astronomer gave a presentation to
Northampton’s city council in 2014 and
pushed for shielding requirements on new
LEDs and a lighting curfew that would
force businesses to stop lighting empty
parking lots at night. He gathered 40 signa-
tures for a “Starry Skies” petition. The city’s
police chief, Russell Sienkiewicz, stood up
in opposition during the meeting, saying
that lighting is the second most important
tool police have, behind more patrols.
“I would ask just for you to consider if
good lighting is important,” the chief said,
according to the Daily Hampshire Gazette.
“If you’re a nurse or a clerk working late
and you have to walk in a dark parking lot
because you are [a] half-hour behind when
a business is closed, would lighting be good
for you? Would you feel comfortable?”
To his frustration, Lowenthal says even
the police headquarters has illegal lighting,
installed as a result of a recent overhaul.
He hopes municipalities can learn from
the example of Davis, California, where
a relatively small group of citizens recently
showed they could have an impact.
Following a pilot project that went
unnoticed, the central California townResearch shows that even partial shields on streetlights cause substantial glare. Full shielding casts light straight down and confines it to the immediate area.
Unshielded lights illuminate a parking lot
of patrol cruisers — and the sky above — at
the police department in Northampton,
Massachusetts. The city’s lighting ordinance
requires shielding. JAMES LOWENTHALDome globe lights Street non-full-cutoff lights Square full-cutoff lightsASTRONOMY: ROEN KELLY