Main Page | See live article | Alphabetical index Thomas Gold (born 1920 May 22) is an American astrophysicist and a member of the US National Academy of Sciences. Table of contents 1 Astrophysics 2 Origins of petroleum 3 References 4 External links Astrophysics Gold is a researcher in cosmology and magnetic fields, and coined the term "magnetosphere" for the Earth's magnetic fields. Soon after the discovery of pulsars in 1968, he correctly identified these objects as rapidly rotating neutron stars with strong magnetic fields. For a number of years Gold promoted the idea that many portions of the surface of the Moon were likely to be covered with a thick layer of dust. His opinion influenced the design of the American Surveyor lunar landing probes, but their precautions turned out to be unnecessary, as Gold had overestimated the extent to which cyclic thermal expansion and contraction would pulverise lunar surface rock. Origins of petroleum Most recently, Gold is famous for his 1992 paper "The deep hot biosphere" in the Proceedings of the National Academy of Sciences, which presented a controversial theory of the origin of oil and gas deposits. Gold believes that crude oil deposits are caused by natural gas flows which feed bacteria living at extreme depths under the surface of the Earth. He also published a book of the same title in 1999, which expanded on the arguments in his 1992 paper and included speculations on the origin of life. According to Gold and others, these bacteria account for the presence of biological debris in fossil fuels, obviating the need to resort to a biogenic theory for the origin of the latter. Bacterial action may also explain oddities in the concentration of other mineral deposits. Most western geologists and petrologists consider petroleum abiogenic theories to be implausible and believe that the biogenic theory of fossil fuel formation adequately explains all observed fossil fuel deposits. Most geologists do recognize that the geologic carbon cycle includes subducted carbon which returns to the surface, with studies showing the carbon does rise in various ways. Gold and geology experts point out the biogenic theories do not explain facts such as helium in oil fields and oil fields being associated with deep geologic features. However, recent discoveries have shown that bacteria live at depths far greater than previously believed. Whilst this does not prove Gold's theory, it certainly lends support to its arguments. A thermal depolymerization process which is converting animal waste to carbon fuels does show some processes can be done without bacterial action but does not explain details of natural oil deposits such as magnetite production. References Thomas Gold, (1992) "The deep, hot biosphere", Proceedings of the National Academy of Sciences 89:6045-6049. Thomas Gold. The Deep Hot Biosphere. Copernicus Books, 1999, ISBN 0387985468. External links Thomas Gold's homepage The Deep Hot Biosphere paper Nature story reporting the discovery of bacteria found living on hydrogen gas 3.5km below the Earth's surface National Science Foundation Life in Extreme Environments" (LExEn) program NSF press release about deep hot bacteria producing magnetite This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.