Summary

This book begins by giving a broad overview of the history of the universe. 13.5 billion years ago, matter and energy came into being with the Big Bang. This was the beginning of physics. 300,000 years later, more complex substances, whose properties and interactions are described by chemistry, emerged. 3.8 billion years ago, life appeared, heralding the beginning of biology. Finally, 70,000 years ago modern human beings, known as Homo sapiens, spread throughout the Earth and began to form cultures, signalling the start of history. Homo sapiens, Harari argues, achieved dominance because of the Cognitive, Agricultural, and Scientific revolutions. He notes, however, that sapiens were not the only humans to ever exist. He states that several other species of humans belonged to the same genus, a biological grouping that denotes a common ancestor. Beyond that, humans are related to apes. Before 8,000 B.C., a variety of human...