Top 10 movies on theaters box office July 2015 third weekend. Check out the list of the top 10 movies on the U.S. and Canada theater box office during July's Third weekend.
If conditions are right, the fused sand forms long hollow tubes called fulgurite. The term comes from the Latin word fulgur, which means lightning. Although lightning strikes earth at least a million times each day, only rarely does fulgurites form. Fulgurites are usually found beneath the surface of the sand, generally decreasing in diameter and sometimes branching outs as they descend.
The actual diameter of a lightning channel is one-to two inches. A typical cloud-to-ground flash is a negative stepped leader that travels downward through the cloud, followed by an upward traveling return stroke. The net effect of this flash is to lower negative charge from the cloud to the ground. Less common, a downward traveling positive leader followed by an upward return stroke will lower positive charge to earth.