These are fascinating sculptures done by Robert Cannon . He calls the work Terraform Sculpture. TERRAFORM (literally, “Earth-shaping”) the process of deliberate modification of the atmosphere, temperature, surface topography or ecology to be similar to those of Earth to make it habitable by humans. While in Robert’s case, he uses concrete and mosses with most of his creations.
Another interesting property of the logarithmic spiral is revealed if you roll it along a horizontal line. This animation shows the curves traced by points on the spiral, and note that the very centre follows the path of a straight line. The angle between this line and the horizontal is called the pitch of the spiral, and for our spiral galaxy the pitch is around 12 degrees. [more] [code]