The corkscrew is from acko.net's excellent article http://acko.net/blog/how-to-fold-a-julia-fractal/ http://acko.net/blog/how-to-fold-a-julia-fractal/ I highly

The corkscrew is from acko.net's excellent article http://acko.net/blog/how-to-fold-a-julia-fractal/ http://acko.net/blog/how-to-fold-a-julia-fractal/ I highly recommend checking it out if you haven't already.