Cognition, Whorfian hypothesis and language complexity

This colloquium examines issues in cognition, the Whorfian hypothesis and language complexity from a complete synchronic description and a hitherto uncharted diachronic account of the Chinese spatial metaphors for PAST and FUTURE. Why does Chinese have two full-fledged and distinct spatial metaphors for indicating past and future? What does this Chinese situation tell us about cognition, Whorfian hypothesis and language complexity?