Author(s): John Gribbin

Science

Life begins with the process of star formation. Except for hydrogen, every single atom of every single element in our bodies has been manufactured inside stars and then scattered across the universe in great stellar explosions known as supernovas, only then to be recycled as part of us. The hydrogen is primordial material, produced in the Big Bang, but everything else has been built up in the burning hearts of stars. We are made of stardust. Here the author relates the series of breakthroughs in astronomy that have led to this almost unbelievable insight into human origins. He begins his rich and characteristically accessible account in the 1920s, when astronomers discovered that the oldest stars are chiefly composed by hydrogen and helium, produced at the birth of the universe. He then describes the seminal work of the 1950s and 1960s which unlocked the secret of how elements are crated by nuclear fusion inside stars. In detail, this book goes on to follow the only recently understood life cycle of a star to its climatic end: supernova, the dramatic death of a star. during these explosions, a single star briefly shines as brightly as a hundred billion suns. The resulting ash is spread far and wide throughout the cosmos, forming new generations of stars, planets, and people. Focusing on the relationship between the Universe and the Earth, the author eloquently explains how the physical structure of the Universe has produced conditions ideal for life. In a Universe where the necessary processes operate with such prolific abandon, life-forms like ourselves cannot be unique.