Auf die Femtosekunde genau!

The scholarly quest for accuracy has been at the heart of watchmaking innovation since the 17th century. From the Second World War, physicists took over from astronomers and horologists in the pursuit of accurate time measurement. From 1967, the second was no longer defined via astronomical observations such as the passage of the sun across the zenith, but by measuring a microscopic phenomenon : the oscillation of caesium atoms.