Inertia and Physics.. Paul Chick

[Richard Brekne]

Hey there Paul, 

Comments below, and I'm spliting my reply into two posts. Thanks for
your encouraging comments and style :)

Paul Chick wrote:
> 
> Richard,
> 
> I think I see where you are coming from on this one.....I am focusing on the
> the part of Don's statement of UNITS of "inertia" as being that since there
> are no units for inertia, more of nothing is still nothing.   You are saying
> that those are two separate statements:  There are no units of inertia.  And
> one object cannot have more inertia than another.  I apologize.....not being
> able to communicate in person is a barrier.  Am I understanding you
> correctly????
> 

Yes, thats definatly part of whats going on. We are saying several
things about inertia at the same time, and seemingly some of that is
self contridictory....depending on how you read the words. Thats why I
ask for clarification. Everyone seems to be in agreement with the
following statements; 

<< There are no units of inertia >>
<< Inertia is that property of mass that resists a change in velocity >>
<< Inertia resists changing velocity according to Newtons 2nd Law >>

But that seems to be as far as I can assert there is agreement. You
mentioned you didnt think Don had said that inertia had nothing to do
with mass, velocity, or anything else. Here is a quote from an earlier
post where had asked for a clarification that could unify two seemingly
contridictory standpoints... and Dons response.

RicB had compared the following two statements and found them in
conflict with each other.

> 1. Don Gilmore... inertia is a concept, not a quantity, has nothing to
> do with size, mass, velocity or anything else. Is simply the fact that
> objects with mass tend to resist any change in velocity. No object
> regardless of mass has any more inertia then any other mass.
>
> 2. Sarah and Mark.... inertia is very much like Don describes, yet
> inertia is mass related... a larger mass will definatly have more
> inertia then a smaller mass.

Don Gilmore replied:
"This is about as close as we're going to get here.  I'm not going to
nitpick."

Now personally... I dont see that its nitpicking to point out that one
says inertia has nothing to do with mass, and another says inertia is
proportional to mass. And I dont really think I am alone in being
somewhat confused as to what/whom I should believe here. We are talking
about the opinion of a PhD (Sarah) and a mechanical engineer (Don).
Ergo.. I ask for both to work out a formulation that clears this up. I
cant see that that has happened.

I'll get to the rest op your note in a seperate post... Thanks Paul

Cheers
RicB