Urban Sprawl And The Night Sky

In most major metropolitan areas, you can count the stars visible inthe night sky on your fingers. Now, the phenomenon is spreading; dueto urban sprawl, bright artificial lights are drowning out thedarkness in more and more of the world. That's bad news forastronomers, public energy budgets -- and many plant and animalspecies. Since the 1970s, scientists have been studying the effectof light on organisms' biological clocks and nocturnal behaviorpatterns. They have found that in urban areas, night migrating birdsorbit bright lights until they drop with exhaustion or collide withbuildings or other birds; that bright lights discourage female seaturtles from laying eggs; that the nighttime travel habits ofmountain lions are disrupted by light pollution; and that smallinvertebrates that normally rise at night to feed on surface algae inlakes and ponds become less active as light levels increase, possiblyleading to more algae blooms and lower water quality. In response,nine U.S. states have adopted "dark sky" provisions and 11 more areconsidering similar measures. [Thanks to Grist Magazine for the summary.]

Thanks to Grist Magazine