Re: Generating Current
For starters, let us make sure we are defining ?current? in the same way. I define current as ?charge in motion.? The motion of charge need not be along a wire; it could be through free space. The charge need not be that of an electron. It can be the net charge (positive or negative) on an atom that loses (or gains) and electron. Such an atom is called an ?ion.?
The way current flows through the human body (including along nerve cells from the brain to the muscles and including an accidental electric shock) is by virtue of the physical motion of ions. I do not know whether this is the eighth method to which physis has referred, but I?ll bet I can come up with a ninth (i.e., a method that is not on his list).
Take a gallon of pure water (as nearly completely de-ionized as possible). Add a couple pounds of ordinary table salt (Sodium Chloride). Dissolve completely. This causes the positively charged Sodium ions to separate from the negatively charged Chloride ions. Run it through a chemical or filtration system that removes all of the Chloride ions. What you have left is a gallon of liquid that contains a high concentration of positively charged ions. Now place a clamp-on ammeter around the drain below your kitchen sink. Pour the liquid down the sink. Your ammeter will detect the physical motion of positively charged something-or-other, and will not care what that something is. You have charge in motion; therefore, you have current.
OK, here?s a tenth method: Use friction (silk against glass or fur against rubber) to isolate an amount of charge. Touch the glass (or rubber) rod to an insolated metal ball. This imparts the charge to the ball. Grab the ball with rubber gloves, and throw it to a friend (who is also wearing rubber gloves). As the two of you are playing ?catch,? there will be charge in motion. Therefore, you have current.
