So, we know the speed of light with zero uncertainty. We also know that values of $\epsilon_0$ (electric constant) and $\mu_0$ (magnetic constant) are known with zero uncertainty.
My questions are quite simple, but I seek a sanity check.
- Why are $\mu_0$ and $\epsilon_0$ known with zero uncertainty?
- What might happen to the uncertainty of the present zero uncertainty constants if the definition of the units is changed in the future SI ?
My guess is :
1. $\Large \frac{1}{\sqrt{ \mu_0 \epsilon_0}}$
and
2. Nothing.
But I would appreciate hearing other's thoughts. Cheers.