this course we will examine one of the fundamental forces- electromagnetism
(the others are gravity, strong and weak). We say electromagnetism because
we now know that electricity and magnetism are intimately related. In
fact, it would be best to say that they are really two forms of the same
force. Electricity and magnetism comprise such a large percentage of our
daily lives. Things like light bulbs, radios and computers clearly rely
on the fundamentals of electricity and magnetism. But, there are so many
other examples of electricity and magnetism in our lives- chemical reactions
(the attraction of one ion to another), light (the motion of electrical
and magnetic fields), etc. It is not much of a stretch to say that electromagnetism
is the most relevant of the fundamental forces.
We will be
building up Maxwell’s equations one at a time, assembling them until
we have the complete set (chapters 23- 31& 34). Much like in mechanics
where Newton’s Laws describe all of the phenomena, Maxwell’s
Equations (plus the Lorentz force equation) will completely describe any
electrical and/ or magnetic phenomena. There is one major difference between
Newton’s laws and Maxwell’s equations- Newton’s are
only valid for some range of speeds and masses whereas Maxwell’s
equations are valid under all conditions. (For a complete description
of mechanics one needs quantum mechanics and general relativity.)
27-28 (& 32-33) present us with some of the circuit applications of
electromagnetism. Once you understand how resistors, capacitors and inductors
function, you only need to add a tad of quantum mechanics to have understand
all of today’s circuits. (Chapter 43 in the “modern physics”
sections gives a wonderful overview of how the building blocks of digital
circuits, diodes and transistors, function at the microscopic level.)
One small warning
to go with the sales pitch: Electromagnetism can be rather mathematical
and abstract. Typically students have difficulty “seeing”
fields. Unlike blocks and pulleys, fields seem to be disconnected from
our everyday experience, but the truth is they are very real. Think about
gravity and its ability to perform an “action at a distance”,
this is one example of a field that we’ve already studied. (There
must be something which tells the book to fall down when it’s let
go. This is the gravitational field; we can’t see it, but it is
One last part of
this section- how the course will be taught. The class will be taught
in a "student-centered" style using various strategies designed to promote
active engagement with the material. Most of our class time will
be spent asking and answering questions, doing demonstrations, and participating
in group activities. This design is not based on a whim, rather
it stems from years of educational research by some rather smart people.
me, I'll listen.
Show me, I'll believe.
Involve me, I'll learn.
Native American Proverb
and I forget.
I see and I remember.
I do and I understand.