0Introduction
IB Electromagnetism
0 Introduction
Electromagnetism is one of the four fundamental forces of the universe. Apart
from gravity, most daily phenomena can be explained by electromagnetism. The
very existence of atoms requires the electric force (plus weird quantum effects)
to hold electrons to the nucleus, and molecules are formed again due to electric
forces between atoms. More macroscopically, electricity powers all our electrical
appliances (by definition), while the magnetic force makes things stick on our
fridge. Finally, it is the force that gives rise to light, and allows us to see things.
While it seems to be responsible for so many effects, the modern classical
description of electromagnetism is rather simple. It is captured by merely four
short and concise equations known as Maxwell’s equations. In fact, in the
majority of this course, we would simply be exploring different solutions to these
equations.
Historically, electromagnetism has another significance — it led to Einstein’s
discovery of special relativity. At the end of the course, we will look at how
Maxwell’s equations naturally fit in nicely in the framework of relativity. Written
relativistically, Maxwell’s equation look much simpler and more elegant. We will
discover that magnetism is entirely a relativistic effect, and makes sense only in
the context of relativity.
As we move to the world of special relativity, not only do we get a better
understanding of Maxwell’s equation. As a takeaway, we also get to understand
relativity itself better, as we provide a more formal treatment of special relativity,
which becomes a powerful tool to develop theories consistent with relativity.