The Bomb Pulse: An Unexpected Gift from Nuclear Weapons Testing скачать в хорошем качестве

The Bomb Pulse: An Unexpected Gift from Nuclear Weapons Testing

Introduction At the height of the Cold War, nuclear powers detonated so many nuclear weapons for testing that it altered the chemical composition of the Earth’s atmosphere. In particular, an increased concentration of an element called carbon-14 made its way into the Earth's biosphere and into most organisms; this became known as the Bomb Pulse. Using it, we may estimate with great precision the time of death of organisms and living tissue, which has unexpected and powerful applications - from forensic analysis to neurobiology to fraud detection. The bomb pulse showcases a resourceful and interdisciplinary application of scientific principles; it's also a great example of how political and military motivations can unexpectedly create scientific opportunity. We will introduce the science behind the bomb pulse, explore its multifaceted applications, and conclude with broader considerations that relate science to society. Speaker Alex Wen grew up in Vancouver, Canada and obtained his BSc. degree from the University of British Columbia, where he studied physics and mathematics. He is currently completing his PhD. degree in physics at Harvard where he studies the fundamental subatomic particles produced at particle colliders. Glossary of Important Terms Element: a fundamental building block of matter that cannot be chemically broken down further. Examples include carbon, nitrogen, lead, iron, hydrogen, and oxygen. Made of protons, neutrons, and electrons. Isotope: a particular type of a certain element that is defined by how many neutrons it has. Biosphere: the places on the earth’s surface (air, water, land) that are occupied by living things. Cell: the smallest functional unit that makes up a living thing. Cells may be on their own or form part of a larger living thing (human, tree, etc.). Fats, proteins, etc: the places on the earth’s surface (air, water, land) that are occupied by living things. DNA: the special structures inside a cell that contain its genetic information. Interpolate: the action of looking at a graph, and obtaining information from it. Want to watch this seminar again and check out other SITN seminars? Check out our YouTube    / sitnboston  , Vimeo http://vimeo.com/sitn, and website http://sitn.hms.harvard.edu/category/... Go to the SITN homepage http://sitn.hms.harvard.edu for more information about our organization and upcoming events.