All of classical physics
In Table 18–1 we have all that was known of fundamental
classical physics, that is, the physics that was known by
1905. Here it all is, in one table. With these equations we can
understand the complete realm of classical physics. First we have the Maxwell equations—written in both the expanded
form and the short mathematical form. Then there is the conservation
of charge, which is even written in parentheses, because the moment we
have the complete Maxwell equations, we can deduce from them the
conservation of charge. So the table is even a little redundant. Next,
we have written the force law, because having all the electric and
magnetic fields doesn’t tell us anything until we know what they do to
charges. Knowing $\FLPE$ and $\FLPB$, however, we can find the force
on an object with the charge $q$ moving with velocity $\FLPv$.
Finally, having the force doesn’t tell us anything until we
know what happens when a force pushes on something; we need the law of
motion, which is that the force is equal to the rate of change of the
momentum. (Remember?  We had that in Volume I.) We even include
relativity effects by writing the momentum as $\FLPp=m_0\FLPv/\sqrt{1-v^2/c^2}$. If we really want to be complete, we should add one more
law—Newton’s law of gravitation—so we put that at the end. Therefore in one small table we have all the fundamental laws of
classical physics—even with room to write them out in words and with
some redundancy. This is a great moment. We have climbed a great
peak. We are on the top of K2—we are nearly ready for Mount
Everest, which is quantum mechanics. We have climbed the peak of a
“Great Divide,” and now we can go down the other side. We have mainly been trying to learn how to understand the
equations. Now that we have the whole thing put together, we are going
to study what the equations mean—what new things they say that we
haven’t already seen. We’ve been working hard to get up to this
point. It has been a great effort, but now we are going to have nice
coasting downhill as we see all the consequences of our
accomplishment.