This is the 8-power Mandelbulb fractal as discovered here, rendered with the path tracer stacy at 2400×1800 and 8192 rays per pixel.


There were some interesting comments on this idea, quoted below.

How do you determine the surface normals? It seems like at some points it should essentially be infinitely porous.

 

As I understand, they do a finite number of iterations. There is a problem, indeed, with it being infinitely porous — you see, with larger number of iterations it gets darker. As I understand, with infinite number of iterations it would be a black body.

 

What a fantastic concept: the surface is so infinitely large and complex, that light literally gets lost in it. So it should get heavier the more light is used to attempt to illuminate it?

 

In physics, a black body is an idealized object that absorbs all electromagnetic radiation that falls on it. No electromagnetic radiation passes through it and none is reflected. Because no light (visible electromagnetic radiation) is reflected or transmitted, the object appears black when it is cold. However, a black body emits a temperature-dependent spectrum of light. This thermal radiation from a black body is termed black-body radiation.

Full Reddit comments here.