It is only since global media and digital communications became accessible to ordinary populations - with Telstar, jumbo jets, the pc and mobile devices - that humans have been able to experience their own world as planetary in extent. What does it mean to be one species on one planet, rather than a patchwork of scattered, combative and mutually untranslatable cultures? One of the most original and prescient thinkers to tackle cultural globalisation was Juri Lotman (1922-93). On the Digital Semiosphere shows how his general model of the semiosphere provides a unique and compelling key to the dynamics and functions of today's globalised digital media systems and, in turn, their interactions and impact on planetary systems. Developing their own reworked and updated model of Lotman's evolutionary and dynamic approach to the semiosphere or cultural universe, the authors offer a unique account of the world-scale mechanisms that shape media, meanings, creativity and change - both productive and destructive. In so doing, they re-examine the relations among the contributing sciences and disciplines that have emerged to explain these phenomena, seeking to close the gap between biosciences and humanities in an integrated 'cultural science' approach.