February 2006
Intermediate to advanced
600 pages
8h 57m
English
We return now to the mystery of the rolling ball from Chapter 2. What we saw there was that we can place a baseball on a table under the palm of our hand and make it rotate around an axis perpendicular to the table, pointing right through the palm of our hand, even though we never twist our wrist in that direction. Somehow, just moving the hand parallel to the table in small “rubbing” circles makes the ball rotate as though we were twisting our wrist! We know this happens, but we had no explanation why. Now that we have learned a bit about quaternions and how to use them to understand what happens when things rotate in space, we can try to “see” what is happening with the ...