World Metrology Day, and first anniversary of the newly defined base units of the Système International: kilogram, ampere, mole, and kelvin.

There are two ways how to discover something radically new in physics. The “obvious” one is to go beyond the realm of the already known, e.g., by building a larger particle accelerator, by creating exotic conditions of matter, etc.

The second way is less glamorous but it can be equally productive. It is the route of metrology and precision measurements. This is how several major discoveries in fundamental physics were made, e.g., the CP violation (enigmatic asymmetry between matter and antimatter), the inscrutable irregularities in the spin rate of the Earth (probably due to an exchange of angular momentum between Earth’s core and mantle), the acceleration of the expansion rate of the Universe, etc.