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}]
A Moiré pattern formed with 2 sets of rays.
Code for Mathematica:Manipulate[
Graphics[
{Thickness[.005],
{Blue, {Line[
Table[{{Cos[t], Sin[t]}, {0, 0}}, {t, 2. Pi/150, 2. Pi, 2. Pi/150}]]}},
{Line[Table[{{Cos[t], Sin[t]}, {0, s}}, {t, 2. Pi/150, 2. Pi, 2. Pi/150}]]}},
PlotRange -> 1],
{s, .5, -.5, .1}]