Big History, the field that studies the entire known past of our universe to give context to human existence, has so far been the domain of historians. In A Most Improbable Journey, Walter Alvarez—best known for his "Impact Theory" explaining dinosaur extinction—makes a compelling case for a new, science-first approach to Big History. He brings a scientist's view to the human story, from the creation of our universe and our planet, the rise of life, the movement of our continents and its effect on human migration, to humanity's ascendance. Alvarez's observations and stories will give readers a new appreciation of the events that have led to the human situation. Through entertaining, bite-sized chapters, A Most Improbable Journey will send readers out in a thousand directions to learn more.