Electric Fields
We all know matter causes the gravitational field and that it is an attractive force the acts only
between masses. It is only noticeable for large masses, not just larger than atoms or the
subatomic particles that make them up, but larger than say a boulder; we would be hard
pressed to measure the gravitational attraction between to grains of sand, which are even
millions of times more massive than the silicon and oxygen atoms from which they are made.!
But there are other kinds of force fields that allow matter to interact with one another, and the
one we are interested in here is the electric fields. We can measure these fields that are
associated with the subatomic particles the protons, and electrons. Unlike gravity, they are not
just attractive, but repulsive. Where gravity is a construct based on two, one mass attracts
another, electric fields are based on three. We notice that a proton and electron attract one
another, but that two protons repel one another and two electrons repel one another. The way
we have dealt with this is to say that the proton has positive charge, and the electron has
negative charge and established the convention that a positive and negative charge attract one
another and that two like charges repel one another. So while the positive proton attracts the
negative electron, the positive proton repels the positive proton, and the negative electron
repels the negative electron. What we mean by a proton having a positive charge physically we
just don’t know, nor of the electron having a negative charge either. We could have called the
proton negative and the electron positive, but we chose the convention to be the other way
around.!
As well unlike gravity, we don’t know that electric charge is a function of mass, and indeed the
proton, which is about 1836 times more massive than the electron carries a charge equivalent
to that of an electron. This is what we want to explore, which is why nature is calibrated as it is.
We hope to show that this calibration allows for life. For instance, if the charges in the protons
are equivalent to one another, but the masses are different, then the acceleration of a proton
attracted to the electron is less than the acceleration of the same electron attracted to the
same proton, and this in turn determines the structure of the periodic table of the elements,
and their properties, that allows for life, among other things.!
Our formulation of electric fields is geometric. We explain the electric field by placing an
arbitrary surface around a point charge and say the field exiting the surface, covers the surface
such as it equals the volume of charge contained in it. We say the electric field, the field, has
a flux, which is itself dotted over the area of the surface , is the charge in coulombs divided
by a constant epsilon determined by experiment contained in that volume:!
!
Thus Q and epsilon are measures for the degree to which this holds, and represent the
calibration of Nature. If they were other than they are, things would work differently, or not at
all, not just in terms of the electric field, but in terms of other aspects of Nature, which seem to
be properly calibrated to allow for something as complex as life, or other aspects of Nature,
like the balance in stars that allows them to give warmth and light to the planets. We measure
in the laboratory if we say charge q in coulombs is q= 1.602E-19C, then ,
where . Thus the electric field is force per coulomb at a point in space!