Wednesday, December 03, 2008

Light Pollution

Last night, we watched a History Channel episode on parallel universes. Actually, it was the second time we watched that episode and we still achieved a brain freeze somewhere after string theory, parallel universes (levels 1, 2, 3 and 4), soap bubble theory, alternate dimensions and...something. This morning's headache likely stems from brusing that the brain incurred while trying to reconcile all the new information.

Here is part of The History Channel's episode description: Some of the world's leading physicists believe they have found startling new evidence showing the existence of universes other than our own. One possibility is that the universe is so vast that an exact replica of our Solar System, our planet and ourselves exists many times over. These Doppelganger Universes exist within our own Universe; in what scientist now call "The Multiverse." Okay.

Don't rush out tonight and look up at the sky expecting to see these other universes. First, the theories state that they are so far away that the light has not or cannot reach us. Next, humans create so much light that we cannot see much of our own galaxy (basically, our own backyard). When it comes to thinking about pollution, few of us put light..yes, light can be a the top of the list. Too bad, because it is the easiest form of pollution to remedy.

Here at the Francis Beidler Forest Audubon Center, we have the 100+-foot, 1000-year-old Bald Cypress (Taxodium distichum) trees that block our view of the night sky. During our nightwalks, the moon (nearly-full to full) rises and provides sufficient light for weak human night vision to navigate the boardwalk. However, in centuries past, even the planet Venus alone would cast shadows upon the Earth. Looking at Earth from space, it is not difficult to see the population centers with sufficient resources to light up the night. For the geography experts out there that do not recall the large island off the southeastern coast of South America, rest easy...the light is from a fleet of squid fishermen lighting the ocean surface to attract their prey.

Besides dimming the effect of Venus and preventing us from fully understanding the parallel universes theories, human-generated light pollution wastes energy resources and adversely affects wildlife. This month's National Geographic Magazine highlighted this issue. [see full article]

"We've lit up the night as if it were an unoccupied country, when nothing could be further from the truth. Among mammals alone, the number of nocturnal species is astonishing. Light is a powerful biological force, and on many species it acts as a magnet..."

"The effect is so powerful that scientists speak of songbirds and seabirds being "captured" by searchlights on land or by the light from gas flares on marine oil platforms, circling and circling in the thousands until they drop. Migrating at night, birds are apt to collide with brightly lit tall buildings; immature birds on their first journey suffer disproportionately." Look at the photo gallery, especially the image that is third from the end.

Image by Mark Musselman

Long artificial days can alter bird migration behavior causing birds to depart too early (fat-ready due to longer feeding days) or too late (fooled by longer days) and therefore be out of sync biological systems (insect prey life cycles, plant food items, nesting habitat, etc.). Additionally, insects attracted to streetlights are changing the feeding behaviors of predator species, such as bats or the Carolina Anoles (Anolis carolinensis) on our porches. Other nocturnal animals change their behavior to avoid being exposed to predators in the unnatural light. Here in South Carolina, adult sea turtles search for dark beaches, while hatchlings navigate to the brightness that should be the ocean's horizon, but can often be a fatal attraction to artificially lighted areas behind the dunes.

"There's also evidence that our grand transformation of the night might have serious implications for our own health. The contrast between dark and light allows our bodies to calibrate our circadian rhythms, such as hormone levels and sleep schedules. Disrupting these can have a dramatic impact. Researchers think this phenomenon may help explain higher breast cancer rates in societies with brighter nights. Studies on shift workers exposed to nearly constant light during the night hours reveal a higher risk for the disease, perhaps because of altered levels of melatonin. Other research shows that blind women have a lower occurrence of breast cancer. One study that looked at a general population also found a correlation between neighborhood nighttime light levels and breast cancer incidence." --Brad Schiber, National Geographic Magazine

See how you can help dim the night at the International Dark-Sky Association's webpage. Who knows? Not only can you improve your health and conserve wildlife in this universe, but maybe you can help yourself and wildlife in a parallel universe. There's that pain in the head again!

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