A NARROW beam of X-rays, passing through the same point of a thin plate of a crystal, and moving in such a way that it successively occupies all the possible positions within a definite solid ...

A symmetry of the laws means that when we observe phenomena from different points of view, ... being symmetric under rotation by any angle about an axis passing through the circle’s center and ...

Now we introduce symmetry by rearranging the field of Bistable Quartets to form a “butterfly” pattern, which is bilaterally symmetric across the vertical axis.

Snowflakes, on the other hand, are symmetric under rotations (about an axis passing perpendicularly through their center) by 60 degrees (also by 120, 180, 240, 300, and 360 degrees).