Rust / Oxidation on suface of the base. (1stdibs.com)
It is interesting that skeptic make dance that actual temperature is below ensemble mean (its natural variation), but werent worried when in earlier decades suface temps were running hotter (also natural variation). (skepticalscience.com)
Lots of experience with 3D graphics, transformations, collision detection, physics, hidden suface determination and bounding volume hierarchies, animation, cubic bezier and Catmull - Rom splines, interpolation, OpenGL (old and modern), multithreaded rendering and asynchronous render worker. (mechanics.stackexchange.com)