plotting - How to plot a spherical spiral in Mathematica?

This is what I am inputting into Mathematica:

x[t]==(cos(t))/((0.1^2*t^2)^(1/2))
y[t]==(sin(t))/((0.1^2*t^2)^(1/2))
z[t]==-(0.1t)/((0.1^2*t^2+1)^(1/2))
ParametricPlot3D[{x[t],y[t],z[t]},{t,-30,30}]