Lorentz=NDSolve[{x'[t]==10(y[t]-x[t]),y'[t]==-x[t] z[t]+28x[t]-y[t],
z'[t]==x[t]*y[t]-8z[t]/3,x[0]==z[0]==0,y[0]==.3},{x,y,z},{t,0,40},MaxSteps->5000];
ParametricPlot3D[Evaluate[{x[t],y[t],z[t]}/. Lorentz],{t,0,40},
PlotPoints->5000,Axes->False, Boxed->False,Background->GrayLevel[0]]

