<s>[INST] It appears to be a coincidence that Einstein's famous equation \(E = mc^2\) can be derived from the equation used to calculate the energy of electrostatic charges: 
\[E = \frac{q^2}{\varepsilon r} - \frac{1}{4\pi \varepsilon} q^2 \int_0^{\infty} \frac{e^{-\mu r}}{r}d\mu.\]

This equation can be proved in the limiting case when the particles are separated, i.e. \(r \gg q\). Then the coulombic term \(\frac{q^2}{\varepsilon r}\) becomes negligible in relation to \(\frac{1}{4\pi \varepsilon} q^2 \int_0^{\infty} \frac{e^{-\mu r}}{r}d\mu\). In this case the integration is done easily and gives \(\ln{r}\).

The equation is restored in its usual form: 
\[ E = \frac{q^2}{\varepsilon r} - \frac{1}{4\pi \varepsilon} q^2 \ln{r}.\][/INST]