The measure of things
Attosecond lasers light up atoms; microscopy breaks new barriers
Measurement science got more nuanced in 2002 and the years after. For the first time, scientists filmed the movements of electrons using ultrashort laser pulses. One understands how marvellous that is when one realises that the pulses last attoseconds (1 attosecond = 10^-18 seconds). Pulses of such durations were till recently inconceivable and are the shortest things made by man. The same year saw the development of cryoelectronic tomography — electronic microscopy at cryogenic temperatures — through which basic life processes could be watched in three-dimensional images of instantly frozen cells. In 2006, microscopy became yet more refined, allowing sharper views of the structure of cells and proteins. Two years later, German scientists filmed the life stages of a zebrafish embryo through a specialised microscope; the film is available online. But nothing compares with the mind-blowing laser tool — reported this year — which can take snapshots of chemical reactions and study their components in unprecedented detail.