Time scales and questions
Big History makes comparisons based on different time scales, or what David Christian calls "the play of scales", and notes similarities and differences between the human, geological, and cosmological scales. Christian believes such "radical shifts in perspective" will yield "new insights into familiar historical problems, from the nature/nurture debate to environmental history to the fundamental nature of change itself." It shows how human existence has been changed by both human-made and natural factors: for example, according to natural processes which happened more than four billion years ago, iron emerged from the remains of an exploding star and, as a result, humans could use this hard metal to forge weapons for hunting and war. The discipline addresses such questions as "How did we get here?," "How do we decide what to believe?," "How did Earth form?," and "What is life?" It offers a "grand tour o...