Isotropic Sperical Waves

\setlength{\unitlength}{1mm}
\begin{picture}(50,55)
  % Kreis M=(25,35) r=20
  \qbezier(25.000,10.000)(33.284,10.000)
          (39.142,15.858)
  \qbezier(39.142,15.858)(45.000,21.716)
          (45.000,30.000)
  \qbezier(45.000,30.000)(45.000,38.284)
          (39.142,44.142)
  \qbezier(39.142,44.142)(33.284,50.000)
          (25.000,50.000)
  \qbezier(25.000,50.000)(16.716,50.000)
          (10.858,44.142)
  \qbezier(10.858,44.142)( 5.000,38.284)
          ( 5.000,30.000)
  \qbezier( 5.000,30.000)( 5.000,21.716)
          (10.858,15.858)
  \qbezier(10.858,15.858)(16.716,10.000)
          (25.000,10.000)
  \multiput(5,30)(20,0){3}{\circle*{2}}
  \multiput(25,10)(0,40){2}{\circle*{2}}
  \put(32,30){\circle*{2}} 
  \put(29,30){\vector(1,0){7}}
  \put(10,30){\vector(-1,0){10}}
  \put(40,30){\vector(1,0){10}}
  \put(25,15){\vector(0,-1){10}}
  \put(25,45){\vector(0,1){10}}
  \put(1,25){$D$} \put(23,25){$A$} 
  \put(30,25){$B$} \put(46,25){$C$}
\end{picture}