The Oklo prehistoric natural reactor and the time variability of the fundamental constants of nature
Description |
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Steve Lamoreaux, Lab Fellow, Los Alamos National Lab explains that 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 a reactor 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 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 constand has fractionally changed by 45 parts per billion, with six sigma confidence. |
Details |
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Title |
The Oklo prehistoric natural reactor and the time variability of the fundamental constants of nature |
Creator |
Lamoreaux, Steve. |
Creator |
University of California, Berkeley. Department of Physics. |
Published |
2004. |
Full Collection Name |
UCB Physics Department Lectures |
Subject (Topic) |
Nuclear reactions Congresses. Nuclear fission Congresses. Radioisotopes in geology Gabon--Congresses. |
Type |
Video |
Extent |
1 streaming video file |
Other Physical Details |
digital, sd., col. |
Archive |
Physics Library |
Note |
Originally produced as a VHS in 2004. |
Usage Statement |
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Collection |
Physics Lectures |
Tracks |
lectures/phys026.mp4 |
Linked Resources |
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