Illustrations of Translation and Rotation
graphics by Samuel P. Batchelor
 
Rotating simple shapes can produce very interesting complex shapes. Here, we start with a circle. If we translate a copy of this circle so that it is tangent to the original circle's center, then rotate it about that center 8 times, we get the image below. The process can be repeated as many times as we like to create more and more complicated shapes.

The same process can be used for a square with an inscribed "x". If we first rotate the square 45 degrees on its center and then perform the afore-mentioned process (translate the shape to a position tangent to the side, and rotate 8 times), the image is more complicated and therefore more interesting. 

As we have so often seen in our experiences with geometry, simple movements can make unexpected larger shapes out of ordinary ones. If we treat the shape on the far right not as a flat square, but as a regular pyramid wire model. We turn it into a three-dimensional design. Viewed from above, it looks exactly the same as before. However, viewed from an angle it looks like the picture below.

If we fill in the sides of the pyramids so that they are solid, not wire frame, models, the shape becomes easier to read.

The solid walls change the aerial view a little.  The walls obscure some of the lines that were previously visible are now hidden.  The new design looks like this:

home