By now you have
seen pictures of the Burj Khalifa Dubai - the world's tallest building. It stands 800 meters (2,625
feet) high and has more than 160 stories. A major concern other than earthquakes, high winds and terrorists
flying airplanes into it is lightning strikes.
Being the highest point in the area, the designers
needed to install a system capable of shunting the energy all the way to ground level and dissipate
it safely in the dry, sandy soil. That requires handling typically 1 to 10 billion joules of energy
with currents as high as 50,000 amps. Thus far, it has worked well. In the unlikely event that I ever
visit the tower, I'll still follow my father's admonition to not touch the light switches or faucet
during a storm - just in case...
Lightning rods were first used by
Benjamin Franklin to protect the tall building in Philadelphia from catching fire
every time a big lightning storm came along. The idea came from his experiments involving flying kites
in electrical storms. Contrary to what a lot of people (RF Cafe visitors excluded), Franklin did
NOT invent electricity; he proved that lightning was a form of electricity.
This
video shows some pretty amazing lightning strikes in slow motion.