Radioactive Iron Rain: Evidence of a Nearby Supernova Explosion
Abstract
A very close supernova explosion could have caused a mass extinction of life in Earth. In 1996, Brian Fields, the late Dave Schramm and the speaker proposed looking for unstable isotopes such as Iron-60 that could have been deposited by a recent nearby supernova explosion. A group from the Technical University of Munich has discovered Iron-60 in deep-ocean sediments and ferromanganese crusts due to one or more supernovae that exploded O(100) parsecs away about 2.5 million years ago. These results have recently been confirmed by a group from the Australian National University, and the Munich group has also discovered supernova Iron-60 in lunar rock samples. This talk will discuss the interpretation of these results in terms of supernova models, and the possible implications for life on Earth.
About the speaker
Prof. John Ellis is a British theoretical physicist, currently holding the Clerk Maxwell Professorship of Theoretical Physics at King's College in London. He graduated from King's College, Cambridge, in 1971 with a PhD in theoretical high-energy particle physics. After two post-doctoral positions at SLAC and Caltech, he settled in CERN (Geneva) and held a permanent position there from 1978. He was twice Deputy Division Leader for the Theory Division, and served as Division Leader for the period 1988–1994. He was a founding member of the LEPC and LHCC projects, and is currently chairing the committee investigating physics opportunities for future proton accelerators. He is also a member of the extended CLIC (Compact Linear Collider) Steering Committee and of the TLEP Steering Group.
Prof. Ellis's research interests focus on the phenomenological aspects of elementary particle physics with important contributions to astrophysics, cosmology and quantum gravity. A substantial part of his extensive work relate directly to experiment: interpreting results of searches for new particles and exploring the physics that could be done with future accelerators. He is accredited with being one of the pioneers of particle astrophysics: the interface between particle physics and cosmology. He has authored nearly a thousand scientific papers, some with over fifty thousand citations. He is the second most-cited theoretical physicist in the world and is currently very active in efforts to understand the Higgs-like particle discovered recently at CERN.
Prof. Ellis is an eloquent speaker, frequently invited to give public and educational lectures on particle physics and related topics. He is also well known for his relentless efforts to involve non-European nations and institutions in CERN scientific and technological activities.
Prof. Ellis was awarded the Maxwell Medal (1982) and the Paul Dirac Prize (2005) by the Institute of Physics. He was elected Fellow of the Royal Society of London in 1985 and of the Institute of Physics in 1991, and is an Honorary Fellow of King's College Cambridge and of the Serbian Physical Society. He has been awarded Honorary Doctorates by the University of Southampton, Uppsala University, the St Kliment Ohridski University, the Ukrainian Academy of Sciences and the University of Cape Town, and twice won the First Award in the Gravity Research Foundation essay competition: in 1999 and 2005. He was appointed Commander of the Order of the British Empire (CBE) in the 2012 Birthday Honours for services to science and technology.
