intothecontinuum:

A Moiré pattern formed with 5 sets of concentric circles.

Code for Mathematica:

Manipulate[
 Graphics[
  {Thickness[.005],
   {Table[Circle[{0, 0}, r], {r, 0, 1, .05}],
     Table[Circle[{2 t, 0}, r], {r, 0, 1, .05}], 
     Table[Circle[{-2 t, 0}, r], {r, 0, 1, .05}], 
     Table[Circle[{0, 2 t}, r], {r, 0, 1, .05}], 
     Table[Circle[{0, -2 t}, r], {r, 0, 1, .05}]}}], 
 {t, 0, 1, .05}]