Light for brevity

Summary, in English

The shortest time interval controlled by a human being is the duration of a light pulse as short as only 100 attoseconds, i.e., 10^-16 s. This "attosecond" light pulse belongs to the extreme ultraviolet range (XUV) of the electromagnetic spectrum, with central photon energy typically between 20 and 200 eV. Related to its brevity, an attosecond pulse has a broad bandwidth covering tens of eV. These are natural time and energy scales to study electron dynamics in atoms and molecules.