Feed the World
As a retired farmer, I know that the information in “Grassoline at the Pump,” by George W. Huber and Bruce E. Dale, about agricultural residues is false in a most dangerous way. There is NO extra residue from the corn harvest. Sure, you can take it away and use it to create fuel. But that residue is desperately needed right where it fell, to renew the soil. All of it and more are needed to sustain our already low organic matter levels created by years of plowing and other unsustainable agricultural practices. Soil can and does “die,” and then it is unable to produce food. Energy creation is important, but so is our ability to feed the world.
Camille Florence Coers
THE AUTHORS REPLY: Biofuels researchers are striving to improve soil fertility as much as possible during biofuels production. Fortunately, there are ways to remove crop residues for use as biofuels while increasing soil fertility. For example, the organic matter can be balanced by reduced tillage practices; by double cropping, where two crop varieties are planted in succession in the same growing season; and by the use of cover crops that replenish the soil. The Dale lab Web site (www.everythingbiomass.org) details some of our work showing how such practices can provide both biofuels and fertile soil.
Your July cover story could not be timelier as oil prices remain volatile. The types of fuels envisioned by “Grassoline” have great potential for aircraft usage. Several U.S. carriers, including Continental Airlines, have conducted successful test flights using alternative fuels, but significant hurdles remain before these can be certified for commercial use. It is critical that we support further research and development for alternative jet fuels.
James C. May
President and CEO
Air Transport Association
Burden of Proof
As an admirer of the Skeptic column, I find it unfortunate that Michael Shermer’s opus 100, “I Want to Believe,” contains what I believe is a serious fault. Shermer cites negative results of tests of the power of prayer to heal. What if God simply declines to cooperate with our tests of His existence? Shermer asks what existed before our universe began. Why should we assume that God did not exist before our universe or before all universes?
I have never seen a scientific test that can prove or disprove God’s existence. In scientific terms, Shermer is correct; the null hypothesis is no argument. In religious terms, faith is everything. In my opinion, separation of church and science is as important as separation of church and state. Scientists who want to prove scientifically that God does not act in our lives play into the hands of religious spokespeople who want to prove that God controls our lives.
The Vision Thing
In “Origins of the Left and Right Brain,” Peter F. MacNeilage, Lesley J. Rogers and Giorgio Vallortigara mention Rogers’s experiments involving keeping a hen’s eggs in darkness so the right eye is not stimulated and consequently the left hemisphere does not develop normally. In humans information from the left visual field of each eye is processed in the right hemisphere, and vice versa. Is this not the case with chickens, or does this fact cast doubt on Rogers’s conclusions?
George F. Feissner
THE AUTHORS REPLY: The projections from eye to brain are different in birds and humans. In birds each eye projects virtually entirely to the opposite hemisphere, whereas in humans the left side of the visual world relative to the point where the eyes are fixating projects to the right side of the eye and then to the same side of the brain, and vice versa. This difference is irrelevant to the point we made about the relative efficiency of lateralized and unlateralized bird brains. It was simply that when lateralization does not develop, unlateralized birds are less efficient at concurrent feeding and predator evasion.