  Astrophysical observations suggest that the fine structure constant (alpha)
may (or may not) be evolving over the cosmological time scale. This raises a
much debated question: is alpha variation due to the variation of the speed of
light (c), elementary electric charge (e), or the Planck constant (h)?
  Previously, we proposed the metrological approach based on the analysis of
the relationships between the fundamental units (e.g. of the length and time)
and the fundamental constants. Our methodology allows one to find how each of
the fundamental constants e, c, h evolves in time and offers a new outlook for
this area. Here we give a brief outline of this approach and the main results
it produces.
