Oklo and the Speed of Light at SLAC’s Next Colloquium!
Dr. Steve Lamoreaux
Los Alamos National Lab
Natural nuclear reactors? Changes in the speed of light? If either of these concepts seem implausible to you now they certainly won't once Dr. Steve Lamoreaux (LANL) delivers his SLAC Colloquium lecture in the Panofsky Auditorium on November 7th at 4:15 pm entitled The Oklo Natural Reactor and the Time Variability of the Fundamental Constants of Nature. This lecture is a rare opportunity to learn not only about Oklo's incredible natural nuclear reactors but also to gain understanding about how the present-day study of these sites may alter our understanding of fundamental constants such as the speed of light. This event is a must-see for the curious!
Details: Two billion years ago, a uranium deposit in Oklo, Gabon,Africa achieved criticality and a nuclear chain reaction was sustained in the deposit for about 100,000 years. Such areactor was possible because the relative isotopic abundance of U-235 was much greater in the past. By analyzing the isotopic abundances of stable fission products in the deposit, it is possible to determine whether low energy neutron absorption resonance energies were different in the past, and thereby determine whether the fundamental constants of physics have changed. The most precise recent analysis of isotopic abundances implies that the fine structure constant has fractionally changed by as much as 45 parts per billion,with six sigma confidence.