In the logarithmic spiral always maintained a constant angle relative to the axis (snail shell) The issue becomes even more complicated if there is no clarity as built a spiral from the center to the periphery or from the periphery to the center. Ask someone to draw a spiral on the right inner loops to the outer. Then he'll cover his drawing, and let him portray right scroll from outside to inside. Naturally, this will be a mirror image of the first spiral. Perhaps, it is worth a little more to think about cuts the paper clip. Because the separation roller into two parts having two mirror coil. But this would mean that if you connect, make together two mirrored spiral, they will disappear completely. And they really disappear! This is based a lot of tricks. But physics is also faced with a problem when they use the model to describe the interaction of opposite charges (positive and negative).