Math Insight

The right hand rule for determining orientations in three dimensions

To determine orientations in two-dimensions, one convention is to use clockwise (CW) and counterclockwise (CCW) to distinguish between the two possible orientations of a two-dimensional object. For example, we could say that the first arrow below curves in a CW fashion while the second arrow curves in a CCW fashion. If the arrows are rigid, no matter how you move them around, you cannot convert the orientation of the first arrow into the second, so long as you keep them in the two-dimensional plane. The second arrow is a mirror image of the first arrow and you can convert between the mirror images without flipping the arrow in three-dimensional space turn inside out..