User:Kgroblee/sandbox

Dark sky movement: light pollution is ruining the view of the stars. astronomy centres in LA are now useless because of day time smog and night time light pollution. Dark sky preserves at national parks have laws to conserve areas of the night sky from light pollution. some famous ones are: Laws implemented to preserve the night sky are: Preserving the night sky is good because: Steps being taken by communities include: references to validate pollution

National Dark-Sky week... what is it? why don't more people know about it?

scotobiology: The great majority of biological systems have evolved in a world of alternating day and night and have become irrevocably adapted to and dependent on the seasonally changing patterns of light and darkness. Light is essential for many biological activities such as sight and photosynthesis. These are the focus of the science of photobiology. But the presence of uninterrupted periods of darkness, as well as their alternation with light, is just as important to biological behaviour. Scotobiology studies the positive responses of biological systems to the presence of darkness, and not merely the negative effects caused by the absence of light.

The Dark-Sky Association was started to reduce the light going up into the sky which reduces visibility of stars, see sky glow below. This is any light which is emitted more than 90° above nadir. By limiting light at this 90° mark they have also reduced the light output in the 80–90° range which creates most of the light trespass issues.http://en.wikipedia.org/wiki/Light_pollution

Over-illumination is the excessive use of light. Specifically within the United States, over-illumination is responsible for approximately two million barrels of oil per day in energy wasted. This is based upon U.S. consumption of equivalent of 50 million barrels per day (7,900,000 m3/d) of petroleum. Over-illumination stems from several factors: Not using timers, occupancy sensors or other controls to extinguish lighting when not needed; Improper design, especially of workplace spaces, by specifying higher levels of light than needed for a given task; Incorrect choice of fixtures or light bulbs, which do not direct light into areas as needed; Improper selection of hardware to utilize more energy than needed to accomplish the lighting task; Incomplete training of building managers and occupants to use lighting systems efficiently; Inadequate lighting maintenance resulting in increased stray light and energy costs; "Daylight lighting" demanded by citizens to reduce crime or by shop owners to attract customers;[15] Substitution of old mercury lamps with more efficient sodium or metal halide lamps using the same electrical power; and, Indirect lighting techniques, such as lighting a vertical wall to bounce photons on the ground. Most of these issues can be readily corrected with available, inexpensive technology, and with resolution of landlord/tenant practices that create barriers to rapid correction of these matters. Most importantly public awareness would need to improve for industrialized countries to realize the large payoff in reducing over-illumination.