rely on dark skies to see dim stars, galaxies and nebulae.
Glare from neighbours' lights can prevent our eyes from
adapting to the dark. But
light from many street lamps is even worse. The
upward light reflects off the air, making the sky glow.
National Geographic Magazine article on light pollution "of
all the pollutions we face, light pollution is perhaps
the most easily remedied." Like other
forms of pollution, the
basic problem is that people have considered the sky to be
a free place to dump excess photons of light.
glow is caused by thousands of lights which either let light
escape upward, or illuminate large areas beyond the
sidewalk, road or parking lot they are designed for. Better
types of lamps are available which direct light downward
and only to the area needing light. These lights
also use less energy and create less glare. This
is where organized groups who have
researched light pollution can,
over time, make a huge difference.
trespass comes from lights which shine unwanted
into your yard or house. The answer is proper complaints. When
a neighbour is asked politely, a
lamp shining into a backyard might be turned off or replaced
with one that shines down. The engineering departments
of many towns will respond to complaints from individuals
or groups. Politicians usually
try to keep their voters happy. There
is tentative evidence also that darkness is important for
bright lights can make it harder to see things, especially
for older people. Often, it is assumed that over-bright lights
make people safer, when, in some instances over-bright
lighting which shines outward can actually make an area less
complain, especially after reading information
in Richmond Hill, Ontario approached politicians about
light pollution in that growing town. Eventually
pollution control bylaw was
Canadian towns with bylaws include Ottawa, Mississippi Mills and Saanich.
vary, but many include:
- requirements that
new light fixtures must be shielded, that is
only shine down
- limits to
the maximum brightness of lights
- requirements that
some lights (such as parking lots) be turned down
after certain hours
are several organizations working to reduce light pollution. All
welcome assistance from people who want to make a difference.