Well-known physicist Freeman Dyson of the Princeton Institute for Advanced Study has a piece in Edge in which he challenges the conventional wisdom on global warming. Along the way he mentions a very interesting theory on the origin of hydrocarbons like oil and natural gas in the earth's crust. The conventional view, which always struck me as highly implausible, is that the oil we consume today was formed millions of years ago by the decomposition of organic matter, such as rafts of floating vegetation.
Some scientific heretics, like Immanuel Velikovsky, theorized back in the fifties that the petroleum actually rained down upon earth as the planet passed through the tails of hydrocarbon-rich comets. Dyson, however, leans toward a theory espoused by the late Thomas Gold. Here's what he writes:
Later in his life, Tommy Gold promoted another heretical idea, that the oil and natural gas in the ground come up from deep in the mantle of the earth and have nothing to do with biology. Again the experts are sure that he is wrong, and he did not live long enough to change their minds. Just a few weeks before he died, some chemists at the Carnegie Institution in Washington did a beautiful experiment in a diamond anvil cell, [Scott et al., 2004]. They mixed together tiny quantities of three things that we know exist in the mantle of the earth, and observed them at the pressure and temperature appropriate to the mantle about two hundred kilometers down. The three things were calcium carbonate which is sedimentary rock, iron oxide which is a component of igneous rock, and water.
These three things are certainly present when a slab of subducted ocean floor descends from a deep ocean trench into the mantle. The experiment showed that they react quickly to produce lots of methane, which is natural gas. Knowing the result of the experiment, we can be sure that big quantities of natural gas exist in the mantle two hundred kilometers down. We do not know how much of this natural gas pushes its way up through cracks and channels in the overlying rock to form the shallow reservoirs of natural gas that we are now burning. If the gas moves up rapidly enough, it will arrive intact in the cooler regions where the reservoirs are found. If it moves too slowly through the hot region, the methane may be reconverted to carbonate rock and water. The Carnegie Institute experiment shows that there is at least a possibility that Tommy Gold was right and the natural gas reservoirs are fed from deep below. The chemists sent an E-mail to Tommy Gold to tell him their result, and got back a message that he had died three days earlier. Now that he is dead, we need more heretics to take his place.
I don't know how this explains the deposits of oil, unless the conditions necessary to form natural gas also form oil, but if Gold was right we have an almost inexhaustible supply of the stuff just waiting for us to develop the technology to go down deep enough to get it.
Just an aside: It's ironic that Edge runs a piece extolling the role of heretics in science when most of their contributors are decidely uncongenial to the most sweeping "heresy" in modern times - the "heresy" of Intelligent Design.
RLC