Electric Charge

What is science really about? Words such as electron, proton, etc. are common in scientific talk. But these things are not the true objects of science, since no one observes electrons, protons and such. They are just talk, or just our ways of thinking about things we really do observe. They are great tools of explanation, and they allow us to formulate laws of behavior and make predictions in a fresh instance.

Consider these observations:

-I run a comb through my hair, then it attracts small bits of paper.
-Glass and rubber rods are rubbed with silk and fur respectively. The glass rods repel each other. So do the rubber rods. But glass rod is attracted to the rubber rod.

How should we talk about this? For some it should go no further than what they see. Perhaps the glass rod itself becomes attractive, and perhaps we’re content to believe that rubbing the rod with silk will always have this effect. But it will turn out to be more interesting (and useful) to suppose that constituents of the objects are responsible for the objects attractive or repulsive behavior.

To explain each case of attraction and repulsion, we need to posit two sorts of objects. They are called together charged particles. Or charges. One is called positive and the other negative. Charges of the same type will repel each other (just as the glass rods repel each other), and charges of different types will attract (just as the comb attracts the bits of paper).

Let’s say for now that the rubbing leads to the charged particles distributed in the objects in such a way as to make the objects attract or repel. There are still other questions: Were the charges already there, or were they created? Maybe we’ll be able to answer these questions through more observations.