If we approach two bodies with very high opposite charges, electrons can jump from the negative to the positive before they touch; Then we say that there was an electric discharge through the air.
Large electrical discharges are called lightning strikes. Its main creator is nature itself.
On hot days the evaporation of moisture is great. At cold altitudes the water vapor forms drops that fall due to its own weight. These droplets fall without reaching the ground, because they return to evaporate when they meet upward currents of hot air, there a friction and are extracted of the molecules of the water, and free electrons to them adherent. These electrons accumulate in the clouds causing them to be charged with electricity. When the electric charges reach a very high value, the electrons jump in the form of a spark (lightning) to other clouds or to the earth.
To provide protection against lightning, a lightning rod is installed at the highest points of buildings.
The lightning rods are made of a metal rod, terminated in several tips covered with platinum, and also a metallic cable strongly connected to earth.
