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 ...
There are few constants that usually come together, $e/m$ also $h/e$. How are they decoupled? If the speed of light is "derived" as Wikipedia states how meter defined and time?
I recently answered a question about the meaning of the word "dimension" as used in physics. In that response, I provided the definition given in the International Vocabulary of Metrology (VIM) and ...
This might be a question to ask in a Chemistry site, but because there is a lot of talk about redefining many units of measurements in terms of Avogadro's Number / the Mole, I was wondering why we ...