Lightening

Lightening

   A storm arrived late last night, the thunder rolling up the canyons around midnight, the dark fog-ridden sky lighting up with bursts of sheet lightning, the comforting sound of rain washing and nourishing the trees and ground, the cold air yet to arrive.  The plants and trees are ready, making their slow progression to close down for the winter.  The bees have begun burrowing into the ground, the hummingbirds apparently already gone (most birds migrate at night so it is difficult to tell when they actually leave).  The summer storms are gasping a last hurrah, a chance to show their might.  As Arizona Highways magazine put it, "When nature thunders, mortals listen. Well they might...a single severe thunderstorm, several miles across, may pack the force of ten nuclear bombs."

   Lightning is a curious phenomenon, just one of earth's methods of replenishing fertilizer to the ground (the oxygen and nitrogen in a strike combine to form oxides of nitrogen that combine with the rain to fall to earth);  but more importantly, the electrical balance is relieved and restored, the positive ions of the earth meeting the negative ions the bottom of the atmospheric cloud.  Here's how Discover described the meeting as the positive charge searched like a crawling web, climbing trees and buildings to find the negative mate:  The now connected leader constitutes a closed circuit, and the effect is much the same as sticking your fingers in an electric socket: the juice begins to flow with a vengeance.  In less than a millisecond, 100 million trillion electrons are deposited on the ground...although the actual flow of charged particles is downward, the point of contact between ground charge and cloud charge is surging upward at 50,000 miles per second, more than a quarter the speed of light...the air (heats) to 50,000 degrees.  Each yard of of hot air in the lightning channel shines as bright as a million 100-watt light bulbs.  It is this brilliance, created by the upward-moving return stroke, that we see as lightning; it only looks like it is going down because it retraces the downward-forking path of the stepped leader, including all the prongs.  As the hot air explodes away, it creates a supersonic shock wave--and a sonic boom of thunder.

   On a few quick side notes, the lightning charge shuts off in a thousandth of a second due to the air cooling so rapidly, frustrating the charged cloud until it can find another area to mate (often this is another cloud, the bright reflection of cloud-to-cloud lightning producing what we call "sheet" lightning...fewer than 25% of lightning strikes are cloud to ground).  The charge when lightning actually occurs can be as much as 100 million volts.

   Throughout history, from mythological times (when Zeus was considered all-powerful hurling lightning bolts) to medieval church bell ringers (at that time, in an article from Sports Afield, it was believed that ringing church bells during a storm would either disperse evil spirits or later on, break up the sound path and thus the lightning storm;  obviously, many bell ringers perished and even today, many church bells are inscribed with the phrase Fulgara frango meaning I break the lightning), we have been fascinated by lightning.  Even today, some scientists speculate that lightning was instrumental in creating the building blocks of life (and perhaps still is).

   Last night, as the storm moved overhead in slow giant steps, my wife and I watched at midnight, the sky waking us up from sleepy eyes and thrilling us again with nature's grace.  It reminded us of a documentary we watched, 180 Degrees South, about one couple's efforts to help establish a conservation area in Patagonia, which included creating their own nursery for native plants and trees (this being Douglas Tompkins and his wife, Kris, both recently featured in the Nature Conservancy magazine).  Despite already protecting 2 million acres for the Chilean people, the power companies and pulp mills are closing in, damming rivers and polluting the ocean's coast.  As Yvon Chouinard (Tompkins former partner in climbing and fortune, founders of the Patagonia line of outdoor gear and clothing) said, "One you lose the outdoors, the wildness, it is gone."

   Staring at the storm, my wife and I couldn't shake the thought of his words.  We needed to lighten our  minds.  And now, the storm was bringing us more than refreshment for the earth, it was bringing us refreshment for our spirits, that the wildness, the mystery, the wonder, was still there...uncontrollable, undaunted, and undiminished.

  

Lightning Myth #2

Surge protectors won't save your electronics (TV, VCR, PC) if lightning strikes your power line. Surge protectors provide protection for power surges in the line from the power company, but not for lightning. To really guard against strike damage, you need a lightning arrester. The arrester uses a gas-filled gap that acts as an open circuit to low potentials, but becomes ionized and conducts at very high potentials. If the lightning hits the line you are protecting, the gas gap will conduct the current safely to ground.