Broader Broadband
“Competition and the Internet” [Science Agenda] is overly simplistic when it argues that broadband in the U.S. is too expensive and too slow.
Today’s most advanced applications typically require seven megabits per second of bandwidth or less, far below the capabilities of most U.S. wireline broadband. This is presumably why a recent Federal Communications Commission survey found that 91 percent of U.S. broadband users were “very” or “somewhat” satisfied with their speeds, and another study found that consumers were not willing to pay much for extra speed. Indeed, consumers in most countries typically subscribe to slower speeds than the highest available. Also, although very high speed connections in the U.S. are quite expensive relative to many developed countries, prices for slower connections compare favorably.
But most important, your editorial focuses entirely on wirelines, although wireless broadband is booming and already affects Internet use, innovation and investment. If fostering competition is the real policy objective, wireless broadband—not net neutrality—has the real potential to enhance competition, especially at slower speeds. Fostering wireless growth is far more important than getting a 100-Mbps connection in every home.
Scott Wallsten
Vice president for research, Technology Policy Institute, Washington, D.C.
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Spectrum of Choices
As parents of a four-year-old who was diagnosed to be on the autism spectrum (the subject of Nancy Shute’s “Desperate for an Autism Cure”) at 15 months of age, we have spent countless hours researching, measuring, experimenting and hoping for something, anything really, that could improve our son’s quality of life. Our search began with conventional medicine, and we frankly hoped it would end there. But the stark reality is that conventional medicine has offered no answers at all and has seemingly been more concerned with vilifying treatments that do not require pharmaceutical intervention.
Gary Latham
Columbia, Md.
Energy Density
Antonio Regalado’s “Reinventing the Leaf” primarily discusses Caltech’s Nathan S. Lewis’s solar energy process, in which water is the base fuel, but there is no mention of water sources. Does the water have to be clean? Is the technology aimed specifically at water-rich places? Or if water desalination is necessary, is the project still worthwhile?
Dov Rhodes
Haifa, Israel
LEWIS REPLIES:The water does have to be clean, but in fact we hardly use any. It is not used for cooling but as the precursor to store the energy in the split forms of hydrogen and oxygen. And it takes a very small amount of hydrogen to store an enormous amount of energy—more than 100 times as much as in a lithium battery of the same weight. Also, the water would be recycled and could come from rainwater or, in many cases, even water vapor.
So water is not really an issue. Demonstrating the technology and getting it to work are much more pressing concerns for us at this stage.
Income Gap
In “Closing the Health Gap” [The Science of Health], Christine Gorman is exactly on target about the need for primary care except for one glaring omission: medical specialists will typically earn at least three times as much as primary care physicians in return for having spent two or three additional years of training. Until this income gap is resolved, the probability of significant numbers of physicians choosing primary care as a specialty is very small indeed.
David S. Grauman, M.D.
Fairbanks, Alaska
Microwave Heat
In “Can You Hear Me Now?” [Skeptic], Michael Shermer argues correctly that cell phones cannot directly break DNA. But he is wrong to assert that cancer only arises after such damage occurs or that cell phones cannot damage DNA otherwise.
A Tufts University study has found that electrical properties of one type of cell can induce other, distant cells to change their behavior. Twelve different European laboratories working as part of a European Union–sponsored project have found evidence of DNA damage from signals from modern 3G phones. Split samples of human sperm studied in six different national laboratories indicate poorer morphology, motility and increased pathology for cell phone–exposed samples. Other studies in Sweden have found that those who started using cell phones as teenagers have four to five times more brain cancer as adults.
Shermer claims that the latest WHO epidemiological studies suggest no overall increased risk in brain cancer tied with cell phone use. But this project is continuing because its leaders understand the need for continued surveillance.
Devra Davis
Department of Epidemiology
University of Pittsburgh
Shermer’s point was that there is not enough energy in microwaves produced by cell phones to cause the breakage of DNA, which can lead to cancer. Although this is true, one cannot conclude that cell phones are not carcinogenic. Research does exist—I am a co-author on a review article relating to it—discussing the carcinogenic effect of elevated tissue temperature with and without coexisting DNA damage from other causes. To my knowledge, no research exists yet on the low-temperature rises that cell phone radiation causes, the increased neurological sensitivity of young individuals, or the unlikely situation where there is known carcinogenic exposure combined with thermal exposure below thermal levels that can cause damage. Consequently, I am hesitant in this case to completely ignore the precautionary principle.
Benjamin L. Viglianti
Department of Radiology
University of Michigan at Ann Arbor
SHERMER REPLIES: [for more on this debate, see www.ScientificAmerican.com/feb2011/skeptic]: Many readers noted that cancer has many causes, such as epigenetic mechanisms that do not require the breaking of DNA chemical bonds, but these other causes are not what most critics are claiming for the alleged connection between cell phone use and brain cancer. Davis agrees with me that “cell phones cannot directly break DNA,” but then she contradicts herself by citing an E.U.-sponsored study on whether DNA damage is linked to 3G phones. The E.U. study has been discredited. The other studies she mentions are either irrelevant or have not been replicated. Viglianti makes a good point that should, in principle, be a testable hypothesis that could lead to a fuller understanding of cancer and its causes. In the meantime, I cannot help but wonder why no one seems concerned about skin cancers caused by holding cell phones in one’s hand and pressed against one’s ear.
