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Text 3. Lightning facts
A bolt of lightning can reach temperatures approaching 28,000 kelvin (or about 50,000
degrees Fahrenheit) in a split second. This is many times hotter than the surface of the sun.
The heat of lightning which strikes loose soil or sandy regions of the ground may fuse the
soil or sand into channels called fulgurites. These are sometimes found under the sandy
surfaces of beaches and golf courses, or in desert regions. Fulgarites are evidence that
lightning spreads out into branching channels when it strikes the ground.
Trees are frequent conductors of lighting to the ground. Since sap is a poor conductor,
its electrical resistance causes it to be heated explosively into steam, which blows off the
bark outside the lightning's path. In following seasons trees overgrow the damaged area and
may cover it completely, leaving only a vertical scar. If the damage is severe, the tree may
not be able to recover, and decay sets in, eventually killing the tree. It is commonly thought
that a tree standing alone is more frequently struck, though in some forest areas, lightning
scars can be seen on almost every tree.
Nearly 2000 persons per year in the world are injured by lightning strikes, and between
1/4th and 1/3rd of those struck die. Lightning injuries result from three factors: electrical
damage, intense heat, and the mechanical energy which these generate. While sudden death
is common due to the huge voltage of a lightning strike, survivors often fare better than
victims of other electrical injuries which result in a more prolonged application of lesser
voltage.
People may be hit in several different ways. In a direct hit the electrical charge strikes
the victim first. Paradoxically, if the victim's skin resistance is high enough, much of the
current will flash around the skin or clothing to the ground, resulting in a surprisingly
benign outcome. Splash hits occur when lightning effectively bounces off a nearby object
and strikes the victim en route to ground. Ground stikes , in which the bolt lands near the
victim and is conducted through the victim via his grounded feet or other body part, can
cause great damage.
The most critical injuries are to the circulatory system, the lungs, and the central
nervous s ystem. Many victims s uffer immediate cardiac arrest and will not survive without
prompt emergency care, which, it is worth noting, is safe to administer, due to the fact that
the victim will not retain any electrical charge after the lightning has struck. (Of course, the
helper could be struck by a separate bolt of lightning in the vicinity.) Others incur
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