 |
Science Frontiers ONLINE No. 114: Nov-Dec 1997 |
|
| 
|
Surface life (us!) only a "special case"
T. Gold is again challenging our most cherished ideas about geology and life's domain. In the subject article -- his latest paradigm-shaker -- he first reviews the abundant evidence for the existence of large quantities of primordial hydrocarbons deep within the earth and (probably) many other planets throughout the universe. Associated with these hydrocarbons is a "deep, hot, biosphere." By "deep" Gold means 100 kilometers and more. It is this combination of a deep reservoir of hydrocarbons and life forms (probably mostly bacteria) that can account for (among other things):
- The fact that all helium comes from oil and gas wells
- The fact that the composition of petroleum is not what one would expect from the decomposition of plants and animals. It is really a mixture of primordial hydrocarbons with some added biochemical by-products; that is, products of that "deep" biosphere.
Since carbonaceous material is now known to be common in the solar system (comets, carbonaceous chondrites, etc.), it is likely that many other planets also possess deep stores of hydrocarbons. In these deep, warm, protected, energyrich "wombs," complex biospheres might readily evolve. In Gold's view, deep biospheres may be the rule and surface life the exception!
Finally, Gold sees life as merely a natural process with no more meaning and purpose than accelerating the breaking of chemical bonds and thereby increasing entropy!
"It has been said that nature abhors a vacuum, but nature doesn't care much for free energy either. All of biology is just a device for degrading energy from chemical sources, and on the surface from the great temperature differential between the hot sun and the cold of space. Perhaps biology is just a branch of thermodynamics, and there is no sudden beginning of life, but a gradual systematic development toward more efficient ways of degrading energy. ...The chemical energy available inside a planetary body is then more likely to have been the first energy source and surface creatures -- like elephants and tigers and people -- which feed indirectly upon solar energy are just a specific adaptation of that life to the strangely favorable circumstances on the surface of our planet."
(Gold, Thomas; "An Unexplored Habitat for Life in the Universe," American Scientist, 85:408, 1997.)
 | Undiscovered microbial life may exist kilometers beneath the surfce. These microbes may be the source of the biological molecules found in the oil shown seeping upwards. Gold believes this oil was originally abiotic. |