American light artist James Turrell creates big, bold installations that generate worldwide fanfare, like his Roden Crater in Arizona or Skyspaces built into mountains or accessed through a swimming pool. But sometimes a Turrell work lives quietly amongst us. In downtown Toronto’s busy financial district, thousands of suits walk past a James Turrell daily. The artwork, entitled Straight Flush, is a sequence of five large vertical rectangles of light lined up on a marble wall on the ground floor of a bank tower. Colours pulsate in pastels — mauve, pink, blue — on a very slow loop that evokes the ever-changing sky. (Or, to cite a lower brow artwork, those retro lava lamps.) The lights are designed to be in constant motion —they appear a different colour and configuration every time you pass by.  Straight Flush is located inside the lobby of the Bay Adelaide Centre, which is free to access during normal business hours.…