Winter Fantasy for Orchestra. Insights and Personal Observations Given by the Composer Background, Inspiration, and Compositional Techniques:

It occurred to him that the answer might lie in dust from space. Every year the Earth accumulates some thirty thousand metric tons of БЂњcosmic spherulesБЂ«-space dust in plainer language-which would be quite a lot if you swept it into one pile, but is infinitesimal when spread across the globe. Scattered through this thin dusting are exotic elements not normally much found on Earth. Among these is the element iridium, which is a thousand times more abundant in space than in the EarthБЂ™s crust (because, it is thought, most of the iridium on Earth sank to the core when the planet was young). Alvarez knew that a colleague of his at the Lawrence Berkeley Laboratory in California, Frank Asaro, had developed a technique for measuring very precisely the chemical composition of clays using a process called neutron activation analysis. This involved bombarding samples with neutrons in a small nuclear reactor and carefully counting the gamma rays that were emitted; it was extremely finicky work. Previously Asaro had used the technique to analyze pieces of pottery, but Alvarez reasoned that if they measured the amount of one of the exotic elements in his sonБЂ™s soil samples and compared that with its annual rate of deposition, they would know how long it had taken the samples to form ...»