My real point was to spur thought about conventions in general. Capacitance
just happened to be one that I was dealing with recently. We as physicists
like to talk about how fundamental, how logical, how pure physics is. About
how the best theory and the best ideas win out because we approach knowledge
in a rational way.
In reality, our notation, our conventions, and our ways of teaching often
come down to a historical "flip of the coin" (should we call the rod "+" or
the fur "+"). Other times it comes down to practical vs theoretical ( U = Q
+ W or U = Q - W). Some times experiment is just ahead of theory (spdf to
designate orbitals). Occasionally, the original ideas were flawed or
inadaquate. Worse is when two different convention gain popularity (is
weight = Gmm/r^2 or Gmm/r^2 - r(omega)^2).
None of this, of course, changes what is actually happening. The universe
doesn't change because of our conventions. But giving a name imparts a
certain amount power to an idea. Students latch on to names and build their
world view around them; instructors use names as if it was obvious that
these are the right ideas to use. We need to recognize and take some
responsibility for the fact that the conventions we perpetuate are often
inconvenient, inconsistent, or just plain incorrect, and that this often
makes the process of gaining underatnading more difficult than it should be.