More lightning facts

Thunder rumbles because the sound is bouncing off of trees building and hills and, with different paths and different lengths of time for the sound to reach you, it rumbles.  Thunder associate with a close lightning strike is a very loud single crack, seemingly simultaneous with the light.

 

A lightning channel has many branches that can also kill, or at least hurt you.  But if the main channel hits you, there is no survival. A fraction of a single amp can kill you, and it doesn’t take many volts either.  The current largely travels trough your blood vessels, as the salty blood is the path of least resistance.  It travels faster than nerve impulses can get to the brain, so you do not feel the pain.

 

If lighten is about to strike you, you will have advanced warning.  Every hair on you body will stand up. It is a weird feeling.  You have the time to say a (quick) prayer, and dive for some place safe (preferably at the same time as the prayer).  A Faraday cage is like a bird cage, or any metal enclosure, A Faraday cage, or inside any metal enclosure, offers protection.  But the best situation is not to be caught in that situation. 

 

The exception to the branched appearance of lightning is triggered lightning. This is man-made and usually accomplished by firing a rocket into the cloud just before lighting is going to strike. This rocket has a spool of wire attached to it and the wire unspools as the rocket ascends toward the cloud.  As soon as the rocket gets close to the highly electrified cloud, there is a bright flash that is perfectly straight, right down the wire, striking whatever the wire is attached to.  The prototype to this technique was made by Ben Franklin  in his famous kite experiment. Fortunately, he did NOT get struck by a full lightning discharge, but merely a week shock.  Had it been a lightening strike he certainly would have been the first innocent person who was deliberately  electrocuted. Many other scientists who set about to duplicate Franklin’s results had less fortunate outcomes. 

 

As a consequence of his, and subsequent fatal incarnations of this experiment, this particular experiment was removed from the list of approved 8th grade science fair projects. 

 

History might have been different.  If Franklin had died, he would not been able to charm the French court and help bring the aid of the French, which was important in our winning our War of Independence. We also would have missed his later inventions of bifocals, the glass armonica (or glass harmonica), a claw to reach distinct objects, the odometer, and the urinary catheter.  (Next week, more comments on lightning protection – promise)