Establish a Cartesian coordinate system Oxyz, with a hypothetical sphere of radius $R$ at the origin. Place $n$ rings of radius $R$ along the meridional circles, all passing through the points (0, 0, R) and (0, 0, -R). The angle between any two adjacent rings is $\frac{\pi}{n}$, and each ring is uniformly charged with positive charge $Q$. The setup is stationary, and a negative charge $−q$ with mass $m$ is performing circular motion on the equatorial plane at a distance $r_{0}$ from the center of the sphere ($r_0\gg R$). Now, give the charge a radial disturbance, and attempt to find the difference between its radial oscillation period and angular revolution period.   The vacuum permittivity is known as $\epsilon_0$.