Physicists Question Feasibility of an American Missile Shield
If it’s not one thing, it’s another. In July an American Physical Society panel raised new doubts about Pentagon plans for a weapons system to shoot down enemy missiles. In theory, the best time to intercept an enemy warhead is in the first three or four minutes after launch, when its blazing rockets are emitting a telltale—and highly trackable—plume. In practice, the panel concluded, technological obstacles may be insurmountable. “It is much more difficult than people had thought,” says physicist Frederick Lamb, cochairman of the group.
Lamb and his colleagues calculated that hitting an intercontinental ballistic missile during its boost phase requires defensive weapons within 250 to 600 miles of the flight path. That is logistically possible if the attacker is a small nation like North Korea and aims its missiles over international waters or allied territory, where they could be hit shortly after launch (if interceptor rockets are larger and faster than current designs). But a medium-size country like Iran could easily tuck launch sites deep inside its borders, well beyond the reach of early interceptors.
The panel also compared the burn times of conventional liquid-fuel rockets with those of advanced solid-fuel missiles during the booster phase. Using solid fuel results in a much shorter burn time (and therefore a narrower intercept window). Put another way, Lamb says, solid-fuel missiles would be virtually impossible to bring down with existing technologies—or any likely to be developed in the next 10 to 15 years. By then, such so-called rogue nations as North Korea and Iran could have them in place. “We aren’t saying boost-phase defense will never be possible,” Lamb says. “These ideas don’t violate the laws of physics. But is it worth doing? Would we make ourselves safer by spending that money on something else? A judgment call needs to be made about money and time and resources, and in this area, reason has often taken a backseat.”
—Kathy A. Svitil
Terror Threats Prompt Scientists to Mull Self-Censorship
Everyone knows the story of the Princeton University undergrad who designed an atomic bomb using information he found in scientific journals. Since the post-9/11 anthrax attacks, researchers have become increasingly concerned that someone less savory—a bioterrorist, for example—could misuse critical details in scientific journals, publications that depend on the free flow of ideas. Last January a group of 32 editors and publishing officials, most from prominent life-science journals, met in Washington, D.C., to consider whether some scientific papers might be too dangerous to publish.
What sparked the conference, conducted by the National Academy of Sciences and the Center for Strategic and International Studies, was the widespread press attention to two research papers. One, published in Science in July 2002, showed how a live and disease-causing poliovirus could be synthesized from various organic chemicals. The other, in the Journal of Virology in early 2001, explained how to alter the mousepox virus so it could infect an otherwise immune mouse. “The concern was that you could repeat this process with smallpox,” explains Ronald Atlas, president of the American Society of Microbiology. “And that would be deadly.”
The Washington meeting produced vigorous debate between those who insisted that scientific inquiry would be harmed by any restrictions on publication and those who were willing to consider some form of self-censorship or self-restraint in the interest of security. Lynn Enquist, editor of the Journal of Virology, was among those opposed to any challenge to open publication. “Censorship is the slippery slope for us,” he says. “We’re very good at identifying good science. We’re not very good at reading the minds of people who might make other uses of it.” If scientists see a problem, he says, they should not submit a manuscript. “Focusing on the journals is focusing on the wrong end of the process,” he says. “Some research work probably ought to be classified in the first place.”
In the end the workshop participants issued a statement, later published in many journals, that sought a middle ground. It defended openness as essential to scientific progress. But at the same time, it encouraged journals to take security issues into account and consider modifying or not publishing an obviously dangerous paper. “I reject the idea that we’ve agreed to censorship,” says Atlas. “We have added an ethical concern to our concern with scientific quality. If we believe that the dangers of a paper outweigh the benefits, then it’s our responsibility as editors to make decisions about whether and how to publish.”
—Michael W. Robbins
Science Establishment Gives Belated Recognition to Women Researchers
By some measures 2003 was a banner year for elite women scientists. Seventeen women were elected to the prestigious National Academy of Sciences in Washington, D.C., and nine women made it into Britain’s corresponding organization, the Royal Society. But for some inductees, the honor was bittersweet. “Honestly, I thought I should have gotten in a while ago,” says Cynthia Kenyon of the University of California at San Francisco, whose two decades of research since the 1980s on the developmental biology of the nematode worm Caenorhabditis elegans finally earned her a place in the National Academy. “It sounds like bragging, but I started a whole field in aging—that aging is regulated by hormones, that it is an evolutionarily conserved process. It was a huge discovery.”
At least one new member of the Royal Society had to wait an unconscionably long time. The doctoral studies of Jocelyn Bell Burnell at Cambridge University in the 1960s led to the discovery of pulsars and helped her adviser to a share of the 1974 Nobel Prize in Physics. This year the Royal Society finally deigned to honor her. She is now the dean of science at the University of Bath.
Candidates are nominated by the current members of the academy and the Royal Society, which are 92.3 percent and 95.6 percent male, respectively. “Every man has a man he wants to see get into the academy. What has to happen is that people want to nominate women,” says astronomer Vera Rubin of the Carnegie Institution of Washington. Rubin was elected to the National Academy of Sciences in 1981 for work that led to the discovery of dark matter. She calculates that 24 women would need to be in every class of those elected for women to make up one-quarter of the academy’s membership by the year 2030. Or, she suggests, the academy could take a more dramatic step and deliberately elect an all-female class.
—Kathy A. Svitil