What can you say about the laser that has not been said before? Not that it was a solution looking for a problem, nor that it has a central role in everyday life through CDs, DVDs and fibre-optic communications — although both of these statements are true. Ever since Ted Maiman got the first laser to work on 16 May 1960, by coaxing deep-red light from a ruby crystal coated on two parallel faces with silver and irradiated by a high-power flash lamp, lasers have become both bigger — the 192 beams of the National Ignition Facility occupy a building that is roughly the size of three football pitches — and smaller, in the form of various single-atom lasers. There has also been an explosion of interest in nanoscale lasers: it might be thought that the diffraction limit would hamper efforts to make solid-state lasers from nanowires, nanoparticles and the like, but researchers have overcome this problem by exploiting the interactions between photons and plasmons in various nanolasers. So let us celebrate 50 years of the laser, and look forward to many more.