Comment on "How many principles does it take to change a light bulb ...   into a laser?" by Howard M. Wiseman, Physica Scripta 91 (3), 033001 (2016)
  In this comment on "How many principles does it take to change a light bulb ... into a laser?" by Howard M. Wiseman, Physica Scripta 91 (3), 033001 (2016) I am analyzing this extremely nicely formulated question in the framework of the Hanbury-Brown & Twiss experiment thus celebrating also its 60th anniversary. I am giving a straightforward, concise and unique answer on this question, emphasizing that the intensity correlations or the photon statistics make the difference between a light bulb and a laser. 
Wolfgang Els\"a{\ss}er
physics.optics