What is Light Pollution?
Light pollution refers to the glow of light we see at night above cities
What Causes Light Pollution?
This urban glow comes from improperly designed street and parking lot
lighting which spills the light to the side and upwards to the sky.
Additional light pollution is caused by lit signs, commercial building
lights, sports facilities, and outdoor residential lights. Light
pollution was noticed first by astronomers. The glow interferes with
their ability to see the stars and galaxies. In a broader context, light
pollution deprives everyone of the joys of seeing a sparkling night sky.
How Does Light Pollution Affect Us?
Glare: The glare that results from light shining sideways or
upwards can be annoying and potentially hazardous to both car drivers
and airline pilots. Glare can be avoided by using properly designed
light fixtures. Good design incorporates shielding that minimizes
sideways and upward light leakage.
Unwelcome Light "Trespass": Light trespass refers to situations
such as streetlights which distribute light out to the sides and into
people's windows. Light trespass is not only a bother and an
inconvenience, it can actually interfere with other people's activities
and use and enjoyment of property. In many cases, simply drawing the
curtains or shutting the blinds would be an answer, but usually the
problem could have been avoided in the first place through good lighting
design and proper shielding.
What Is The Cost of Light Pollution?
Light pollution is also a sign of waste. There is no benefit from
lighting up the sky. Depending on the specific type of light fixture, as
much as 25% of its light may be wasted.
Note: Local Dark Sky rules and
ordinances vary greatly by state, country and locality. While
every attempt to reduce light pollution helps, please check with your
local municipality to determine if a specific fixture meets your
municipalities standards and/or legal requirements.