How much time can you imagine? A hundred years? A thousand? Even a million? Just how far does time stretch back? And where do we fit in? These are the questions Michio Kaku asks in this episode of his series about the nature of time.

From the calculations of a 17th-century Irish bishop to the secrets of meteorites, Michio finds out how vast Earth time really is. It is a journey that takes him to the Grand Canyon, the Arizona Meteor Crater and the most active volcano in the world in Hawaii.

Things we see as constant are really changing through time - our planet, life, and even us. These time spans reveal just how insignificant and transient we are. But Michio looks to our own journey to suggest that there might be hope for future of humanity after all. Show less