Shock Treatment

I’m sure that all of you have read of, somewhere, or seen on television, this scene: A man is brought into the hospital emergency room having suffered a heart attack, or having been under water for some time.  The frantic doctors and nurses are doing everything they can for the man—artificial respiration, injection of drugs, testing and so forth—but nothing works.  Finally, as a last resort, they take two disk shaped objects with handles on them, rub them together with a conducting element and,...