<[Bill Leach 940909.10:25 EST(EDT)]

Bill Powers

Probably about a month ago, in a discussion of some kind you made some
remarks about a little experiment that you performed.

You mentioned noting a significant difference between touching a glass
with the end of you fingernail as opposed to your fingertip. I thought
that this was interesting and curious so I have been "playing" with that
for awhile.

I think that your premise is correct but that possibly the behaviour
might be dependent upon the specific individual. That is, I think that
different people have different levels of sensitivity (or more
importantly the ratio of "fingertip sensitivity" to "fingernail
sensitivity" may be greater than unity, unity or possibly even less than

I notice that even the particular finger that is used in the experiment
changes the results (perception of anyway).

I find that I personally experience little to no "tremor" if my wrist or
forearm is supported with the fingernail but "sense" a slight tremor with
the fingertip. If the arm or wrist is not supported then the reverse
seems to be true.

I did not have any "pressure or force" sensors so I suppose that the
whole thing might be "hogwash" but it was interesting anyway.

As soon as I can find something around here that is suitable to the
purpose, I thought that maybe suspending a glass rod from the ceiling and
repeating the experiments should prove interesting. In that case the
suspended glass rod should provide physical evidence as to how severe any
oscillation might be.