by Kenneth W. Krause.
Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer. Formerly a contributing editor and books columnist for the Humanist, Kenneth contributes regularly to Skeptic as well. He may be contacted at email@example.com.
Does our new president appreciate the basic science behind terrorism, energy, nuclear weapons, space exploration, and global warming? He probably knows a lot more than the vast majority of his constituents, quite honestly, which is really why physics professor Richard Muller wrote this persistently engaging and occasionally surprising little book. A potent distillation of his science-and-society course for non-science majors at the University of California, Berkeley, Physics for Future Presidents casts a refreshingly skeptical glance on several of the 21st century’s most sacred scientific cows.
Because Americans use about 28 percent of their fuel for transportation, electric and hydrogen powered vehicles are often either touted as the inevitable waves of the near future or bemoaned as the innocent victims of greedy oil companies. But neither optimism nor opulence can prevail over the physical facts. The news is “full of hyperbole” about electric cars, Muller warns, especially with regard to the new Tesla Roadster and plug-in hybrids. He might be right. In the September 20, 2008 issue of NewScientist, for example, Jim Giles judged that “[e]lectric cars are coming of age.”
Pound for pound, however, even the best batteries can store just one percent of the energy contained in gasoline, as Muller points out, and, of course, all batteries need to be replaced after a limited number of charges. (Even according to Giles, lithium-ion cells—found in the Roadster, for example, can withstand only 5000 recharge cycles, while nickel-metal hydride batteries—common to the Toyota Prius—can take about 3000). Recently marketed, most Priuses will be fine for a while, and driving them will seem relatively cheap. But owners should bank their pennies for the second battery. “Who killed the electric car?” Muller chides. “Expensive batteries did.”
Hydrogen, on the other hand, holds 2.6 times more energy per pound than gasoline. Maybe that’s why some enthusiasts say that a “hydrogen revolution” is only 10 years away. Unfortunately, because it’s so light, a pound of hydrogen fills a lot of space. We can compress it, but then we have to store it in a heavy container. We can liquefy it too, but even fluid hydrogen is relatively buoyant. Solid hydrogen technology is not an option because it has yet to emerge from the laboratory. Compressed hydrogen will give us only five miles per gallon, says Muller, and its liquid form can give us no more than ten. So, in reality, hydrogen actually provides three times less energy than gasoline.
But, because hydrogen is less an energy source than a means of storing energy, the usable fuel must be manufactured—either through electrolysis, which breaks up water into its elemental components, or through “steam reforming,” which creates hydrogen by reacting natural gas (methane) with steam. Either way, a great deal of energy is burned in the process. And what about infrastructure? To date, there are only 26 refueling stations in California and 150 worldwide. Muller concedes that hydrogen has some potential uses, such as in ultra-light airplanes or in large vehicles like buses that can support capacious fuel tanks and stop for frequent refills. But the physics of hydrogen, he insists, ensure that the would-be “revolution” will remain ten years away for a very long time.
And speaking of extended lags, Muller and approximately 77,000 tons of American nuclear waste have waited far too long for the government to open up Yucca Mountain, Nevada. Fission fragments such as strontium-90 are among the most dangerous forms of nuclear litter. Because of their short half-lives, these fragments are much more problematic than plutonium (which Muller contends should be reprocessed in the United States) and about 1000 times more radioactive than the original uranium ore. So it will take about 10,000 years for the waste to decay back to the level of the originally mined uranium.
Even so, Muller disagrees with those who argue for 10,000 years of absolute safety. The public discussion, he says, should take account of the physical and mathematical facts of radioactive decay. Because the waste’s radioactivity is only 1000 times worse than that of the original uranium, our goal should be to reduce the risk of leakage to 0.1 percent (one chance in a thousand), which is equivalent to the risk of simply leaving the uranium in the ground. But after 300 years, the fragments’ radioactivity will be only 100 times that of the uranium, so we could accede to a 1 percent chance of total leakage, Muller calculates, or a 100 percent chance of 1 percent leakage.
The Department of Energy, however, is concerned about earthquakes as well, and many contend that the discovery of a new fault under Yucca Mountain should completely disqualify the site. But, again, the relevant standard is not absolute security. The question is not whether any earthquake will occur during the next 10,000 years, but, rather, whether there exists a 1 percent chance of a sufficiently dangerous earthquake (causing 100 percent leakage into the groundwater) after 300 years. Alternatively, Muller argues, we should accept a 100 percent risk that 1 percent (or a 10 percent risk that 10 percent) of the waste will escape.
If Yucca Mountain were at full capacity, and all of its waste were to leak out of its glass pellets and seep into the groundwater, the resulting problem would still be 20 times less severe than that posed by the natural uranium currently floating around in the Colorado River, which—not so incidentally—provides potable water to much of western America, including Los Angeles and San Diego. “[W]aste leakage from Yucca Mountain is not a great danger,” Muller judges. Instead, we should worry more about “real threats—such as…the continued burning of fossil fuels.”
Quite regrettably, “much of what the public ‘knows’ about global warming,” the author adds, “is based on distortion, exaggeration, or cherry picking.” After scientists discovered in 2006 that Antarctica was losing 36 cubic miles of ice per year, for instance, the media widely and hastily reported the damage as compelling new evidence of global warming. But, as the experts had noted, because warming increases oceanic evaporation and because the extra water vapor falls as snow when it reaches Antarctica, global warming would actually increase the Antarctic ice mass.
Although he by no means denies warming or its recent anthropogenic causes, Muller assails An Inconvenient Truth, Al Gore’s popular film, with conspicuous vigor. Gore had employed a version of Michael Mann’s famous “hockey stick” plot in a dramatic and memorable attempt to show that world temperatures are currently higher than they have been in at least 1000 years. But the National Research Council of the National Academy of Sciences subsequently declared the plot to be seriously flawed, concluding that, at best, temperatures are now higher than they have been in about 400 years—which was already common knowledge. Former vice president Gore, Muller scolds, won the Nobel Prize “through a combination of artistry, powerful writing, and exaggeration, mixed with some degree of distortion and a large amount of cherry picking.”
Physics for Future Presidents is anything but comprehensive, of course. Nevertheless, Muller offers casual readers an approachable and truly delightful cornucopia of general science education. Perhaps best of all, however, the text forces us to question conventional wisdom and to wonder about all of the intriguing facts and arguments that we, as responsible Americans and citizens of the world, have been ignoring for far too long.