Touchweight was Cockeyed hammers / Don Gilmore

[Mark Davidson]

When all else fails, I turn to the dictionary.  Especially when arguing about the meanings of words.  Here's what mine (American
Heritage ca.1975) says:

inertia: n. 1. Physics.  The tendency of a body to resist acceleration; the tendency of a body at rest to remain at rest or of a
body in motion to stay in motion in a straight line unless disturbed by an external force.  2. Resistance to motion, action or
change.

So right away there's a problem, since definition (1) is really two definitions.  The first, a tendency to resist acceleration, is
definitely quantifiable in terms of how much force it takes to changes something's velocity (i.e. force / acceleration, essentially
what we've been calling mass).  This is also what I would consider the common English-language use of the word.  I.e., when you push
on something, it pushes back, and the more inertia it has, the harder it pushes back (Oh dear, there's another whole can of worms.
No it pushes back with exactly the same force, but our sensitive fingers can tell by how much it moves how much inertia it has.) The
second is Newton's first law, that things don't change velocity on their own (and in particular, it doesn't take force to keep
something going once it's moving, which was hotly debated pre-Galileo).  This second usage is Don's "scientific property" of
inertia.  This was a very important concept since orbiting planets move in circles, implying there must be a force acting on them.

Ironically, I had a helluva time fishing any kind of useful definition out of my physics book.  Stuff like: "In this section we have
used the terms force and mass rather unprecisely, having identified force with the influence of the environment, and mass with the
resistance of a body to be accelerated when a force acts on it, a property often called inertia."  Then goes on to give Newton's
first law.

Anyway, I would assert that we are suffering from the vagaries of language as much as anything.  There are two meanings - related
enough to be confusing, but not the same.

-Mark