Every high performance driving school I have been to has talked about the physics behind these skills, but in fact it is seat time (the analog to hands on training with a teacher when talking about internal skills) which develops these skills.
Good points from Kevin and Hunter. There is no substitute for subjective experience, but there is also no substitute for objective understanding. I won't dwell on implicit presumptive judgments from writings, one way or the other. I also won't clobber the discussion with a rather lengthy summation that Hunter's post prompted me to pull together from my strands of continuing work on these topics from these and some offline discussions I have been having, I think it clarifies the state of my thoughts on physical mechanics, perception and aiki.
If any one is interested, I have posted them here: http://www.aikiweb.com/blogs/but-why...and-aiki-3083/
If not, well God bless, and pass the mustard. If, however, you find the following image resonates at all with your experience of aikido dynamics (the 3d path depicted changes along its length of travel from initially red through purple to blue ), you might waste ten minutes reading it: