Am I the only one who finds a problem with the term "feeling acceleration"
that has been so freely used recently on this list? I cannot believe that
I have any sense mechanisms for accelerations, whether in my glutei maximi
or my inner ears -- if I did have such mechanisms, they would
continually be triggered by all the accelerations I am continually
subjected to. Acceleration is a purely kinematical notion, and is totally
meaningless until you specify a particular reference frame. I am always
accelerating relative to someone's reference frame -- why do I not feel
that if I have sensors for accelerations? The fact is we ONLY have
sensors for the dynamical quantity pressure = force/area, and such sensors
are distributed throughout our bodies. As discovered by Newton and
confirmed by Einstein, ONLY relative to inertial frames of reference do
accelerations have any correspondence with the forces we feel. Why should
we say we feel accelerations when it is actually only forces that we feel?
I can hardly think of a more misleading or confusing practice. We seem
to be mesmerized by the misnomer "accelerometer" for an instrument that
registers zero unless it is acted upon by a force! It is high time we
cleared up such silly confusions.
A. R. Marlow E-MAIL: marlow@beta.loyno.edu
Department of Physics, Box 124 PHONE: (504) 865 3647 (Office)
Loyola University 865 2245 (Home)
New Orleans, LA 70118 FAX: (504) 865 2453