Julia Sets

AI authored to showcase ironpad capabilities.

Julia Sets *

Julia sets are close relatives of the Mandelbrot set. While the Mandelbrot iterates z \mapsto z^2 + c with z_0 = 0 and varies c across the image, a Julia set fixes c and varies the starting point z_0.

Each point c in the complex plane defines a unique Julia set. Points inside the Mandelbrot set produce connected Julia sets; points outside produce disconnected "Fatou dust."

The Connection

The Mandelbrot set is essentially a map of all Julia sets — each pixel of the Mandelbrot tells you what the Julia set at that c value looks like:

  • Inside the Mandelbrot → connected Julia set
  • On the boundary → maximally intricate Julia set
  • Outside the Mandelbrot → disconnected dust
Julia Set: c = −0.7 + 0.27i
Julia Set: c = 0.285 + 0.01i

* How c Changes the Shape

The parameter c completely determines the Julia set's geometry:

c valueCharacter
c = 0Perfect circle (unit disk)
c = -1"Basilica" — two tangent circles
c = -0.123 + 0.745i"Douady's rabbit" — three lobes
c = iDendrite — tree-like, no interior
c = -2Line segment [-2, 2]

The boundary between connected and disconnected Julia sets traces out exactly the Mandelbrot set! Try picking a c value from the Mandelbrot notebook and rendering its Julia set here.