To determine the true age of the Earth, geochemist Clair Patterson developed the uranium-lead dating method to make an unprecedented discovery - calculating Earth's age of 4.5 billion years. But Patterson's groundbreaking discoveries were just beginning. Patterson made it his mission to draw public attention to the detrimental effects of lead in the environment and dedicated his career to fighting against the petroleum and chemical industry, eventually achieving public health's biggest victory of the 20th century.
Active galaxies pour out lots of energy, due to their central supermassive black holes gobbling down matter. Galaxies tend not to be loners, but instead exist in smaller groups and larger clusters. Our Milky Way is part of the Local Group, and will one day collide with the Andromeda galaxy. Clusters of galaxies also clump together to form superclusters, the largest structures in the Universe. In total, there are hundreds of billions of galaxies in the Universe.
Four astronomers celebrate 50 years of work and friendship by going on a road trip to revisit some of the world's greatest observatories. In California, a world leader in observational astronomy at a time when America's space programme was at its height, the astronomers spent their formative years developing friendships that would last a lifetime, and making scientific discoveries that would change the course of history. Together they represent the most productive period astronomy has ever had. Their journey through the southwestern United States allows them to see once again the places and landscape they explored as young men. Now in their 70s, they share their reflections on a life spent looking at the universe. Star Men celebrates the history of stargazing: the inventions and discoveries that have enabled us to learn so much about the universe, but more importantly to understand how much more we have yet to discover.
2016 • Astronomy