Re: Kinds of Mass

[Leigh Palmer <palmer@SFU.CA>]

> In class, I still talk about the question of whether inertial mass and
> gravitational mass are equivalent because I am under the impression
> this is still a legitimate and ongoing area of physics research.
> However, I admit I might be out of date on this.  It seems like I
> read, in the past year or so, of ongoing experiments in this area.
> However, the last time I thought I read something "just last year,"
> and then finally found the journal article, I discovered I had actually
> read it about 6 years ago.  Geesh, it's terrible what aging and being
> busy do to the memory.
>
> Does anyone on the list have recent experience/knowledge to bring the
> rest of us up-to-date on whether people are still doing experiments to
> test the sameness of inertial and gravitational mass?

People also do measurements of the lifetime of the proton, of the
minus two-ness of of the separation dependence in Coulomb's law,
and of the mass of the neutrino. All that is legitimate and ongoing
physical research, but usually I just mention it in passing in
elementary courses. While such things are interesting, devoting too
much time to them in an introductory course can dilute the more
important concepts and confuse the new student about just what is
relatively more important.

Toaday I gave a sound lecture to my introductory students (no, I
don't usually lecture telepathically). I told them about musical
scales and timbre and a couple of other things, but I appended the
code words "This won't be on the final exam" so they would place it
properly on the importance spectrum. They still seemsed interested,
however.

Leigh