Quick insights from twitter into vector products
I love twitter specifically because it presents me with so many ideas, even new ways about thinking about old things or ideas I thought I already understood. Here’s today’s example, courtesy of Superfly Andy Rundquist:
and Joe Heafner promptly responded with
I don’t know about you, but my first introduction to dot and cross products was filled with trying to understand i,j,k notation and follow weird procedures for manipulating vectors in a matrix form, and I had no clue what I was doing, nor did I understand the significance of what I was calculating.
How great would it be to simply introduce the cross product to a class with Andy’s question? Stand next to a kid, ask “how much of you is perpendicular to me?” Then lean over to the side at a 10 degree angle and ask the question again. Students could probably measure this with a meter stick. Later try all sorts of other situations, like clock hands, and later, more abstract ideas like position and momentum vectors.
This would have helped 19 year old me out tremendously.