A Most Improbable Journey by Walter Alvarez Big History, the field that integrates traditional historical scholarship with scientific insights to study the full sweep of our universe, has so far been the domain of historians. Famed geologist Walter Alvarez—best known for the “Impact Theory” explaining dinosaur extinction—has instead championed a science-first approach to Big History. Here he wields his unique expertise to give us a new appreciation for the incredible occurrences—from the Big Bang to the formation of supercontinents, the dawn of the Bronze Age, and beyond—that have led to our improbable place in the universe.