photographed by Lennart Nilsson ; written by Thomas Friedman ; directed by Mikael Agaton ; produced by Mikael Agaton, Thomas Friedman, Lars Rengfelt ; a coproduction between Swedish Television ... [and others] ; WGBH Boston
a PBS digital presentation ; a Gemini Productions film for the WGBH/Nova Science Unit and Clear Blue Sky Productions ; written and directed by Gail Willumsen ; produced by Jill Shinefield, Gail Williamson