Bulletins

Smaller and smaller …

Machines are getting both smaller and smarter all the time, as reported in a number of articles in Science and New Scientist last fall. And sometimes, it seems, all of those little machines belong to the military. For instance, a series of small-to-miniature pilotless planes has been developed for a variety of military uses. Yet, ingenious as they are, with some researchers predicting the practical development of “smart dust,” even the smallest of the current crop of planes could soon be considered ungainly and unsophisticated.

Oh sure, maybe we should be impressed by the Naval Research Laboratory's “sniffer planes”–small craft designed to fly low over the battlefield, their on-board sensors continually sampling the atmosphere for traces of biological weapons. They operate just like radio-controlled toy planes.

Or maybe we should be more impressed by a much smaller device, the “WA SP” (“wide-area surveillance projectile”), which is being developed by John Deyst of MIT. It has a wingspan measured in inches–when its wings are spread. But this toy-sized plane folds up to fit in an artillery shell, which is then shot from a cannon (trials last summer proved it could survive the blast). As the WASP project moves toward making the plane airworthy as well, it is seeking funding from darpa, the Defense Advanced Research Projects Agency (the sniffer planes already have darpa funding).

When it comes to robots, small and smaller is also the name of the game. It is not useful, however, to imagine that these robots are going to have those humanoid features that seem so natural to those of us who grew up on the classics of science fiction.

Unfortunately, the march of time has long since passed the image of the friendly, humanoid-appearing robot handling the household chores. Robots are not going to be folding the laundry any time soon. And as for looking human, they are anything but.

Take, for instance, the robots developed by Vander-bilt University's Ephrahim Garcia and Michael Gold-farb–tiny flying and crawling insect-like devices. Like the creatures whose appearances they imitate, these small machines may move unobtrusively–through a minefield, perhaps, or into a terroristheld building. Armed with the right monitoring devices, they could make very small and nearly unnoticeable spies. Darpa is also funding the “autonomous observer” (AO)–another small, mobile robot under development at Stanford. So far, the AO can tirelessly track a single individual for 24 hours a day–provided its quarry remains inside a single building. A GPS (Global Positioning System) receiver will eventually give it greater latitude.

Just as insect-robots are going to scurry along the landscape, robotic sea creatures are going to swim–or slither–in the sea. Joseph Ayres, a neurologist at Northeastern University's Marine Science Center, has been working hard on “robot lampreys,” and his prototype lamprey successfully imitates its namesakes' eel-like wriggling motion. Ayres, who also has a grant from DARPA, is developing his lampreys to search for undersea mines, but he likes to emphasize that they will eventually have civilian uses, too. If their mine detection equipment is replaced by cameras or sampling techniques, he says, they could explore almost anywhere in the ocean. Ayres is also interested in the locomotion of other marine creatures and plans to build robotic lobsters, salamanders, and stingrays as well.

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“Bad dog!”

Meanwhile, all these little robots are going to be getting smarter. Inside their little insectoid or fishy heads–if they have them–will eventually be embedded circuits that mimic the human cerebellum. Salk Institute neurobiologist Terence Sejnowski and his colleagues have been developing software that allows a robot to make short-term predictions. Using a model of human behavior, the Salk researchers have taught the robot how to anticipate events, like deciding where a moving light is likely to be in the next instant. Sejnowski and his colleagues are mainly interested in how the human brain functions. But if they can make the robot behave more like a human, they will at the same time be developing software that can be used to produce smarter robots.

So should we be impressed by these robots? Yes, of course. But there's another factor tending toward rapid change in the field. That is the maturation of microelectro-mechanical systems, or MEMS–this decade's marvel of nanotechnology.

Just like the incredibly complex and tiny computer chips that give devices brain power, mems–equally complex and tiny mechanical systems built on similar small silicon chips–are going to revolutionize the mechanics of many devices.

Some mems are no bigger than a speck of dust–but they can be incredibly complex. And the advantages of their size are startling: At Sandia National Laboratories, an electrostatic motor was used to spin a wheel with a diameter of 0.3 millimeters at a rate of 350,000 revolutions per minute. Researchers think they can take advantage of ultra-low friction and inertia due to the wheel's incredibly small mass to design a system that will run at 10 million rpm.

And mems are not tomorrow's technology. They are used every day in automotive air bags, and the researchers at Sandia have developed mems to replace earlier locking devices in PALs–the permissive action links that prevent the unauthorized use of nuclear weapons. Darpa is also funding a project at trw Space and Electronics that is developing a MEMS-based steering system for miniature (fist-sized) satellites. The idea is to use swarms of satellites to function as a giant radiotelescope. With 100 micro-thrusters on each of the mems, they could nudge each satellite into its precise location and keep it there.

Using the same principle as that for the mems that will lock nuclear weapons against unauthorized use, the Sandia group has developed another microelectro-mechanical device that is sure to be a big seller once it is commercially manufactured: Described in an October 12, 1998 Sandia press release as the “world's smallest combination lock,” it sets up a “firewall” to prevent hackers from entering a computer. Larry Dalton of Sandia says that the advantage of the “Recodable Locking Device” is that it is hardware rather than software, and “extremely difficult to break into.” Dalton adds that a hacker has “one and only one chance in a million of picking the right code.” And, “after one failed try, this new device mechanically shuts down and can't be reset and re-opened, except by the owner.”

So, how small is small in this brave new world? Well, the entire computer locking device is about the size of a shirt button. And some researchers, including Karen Markus of the MEMS program at MCNC, a publicly funded technology incubator in Research Triangle Park, North Carolina, believe that MEMS particles, equipped with sensors, processors, and communications elements, will easily be able to operate as complete surveillance systems, or “smart dust.”

–Linda Rothstein

The do-it-yourself reactor

David Hahn wanted to be an Eagle Scout, but he was not interested in typical merit-badge projects. Instead of astronomy, backpacking, or business, Hahn was interested in producing energy. He set out to build his very own breeder reactor in his mother's potting shed.

Hahn never built anything resembling a working reactor. But his merit-badge project got some attention. On June 25, 1995 agents from the Environmental Protection Agency (EPA) raided his home in the quiet Detroit suburb of Golf Manor. The extremely high levels of radioactivity the EPA found in his backyard shed prompted the agency to declare it a federal Superfund site.

Hahn was remarkably resourceful in his search for radioactive substances. According to Ken Silverstein (“The Radioactive Boy Scout,” Harper's Magazine, November 1998), Hahn “figured out a way to dupe officials at the Nuclear Regulatory Commission [NRC] into providing him with crucial information he needed in his attempt to build a breeder reactor, and then he obtained and purified radioactive elements such as radium and thorium.”

Even at age 15, Hahn knew how to ask NRC officials for information about how to isolate radioactive elements, which isotopes were capable of sustaining a chain reaction, and where he could find commercial sources of radioactive materials. “The NRC gave me all the information I needed,” he told Silverstein. “All I had to do was go out and get the materials.”

Not that he had to look very far for most of his “reactor” elements. In an interview on CBS This Morning (October 19, 1998), Hahn listed his sources: “I found lantern mantels, which contain thorium dioxide. They sold these at Kmarts. … [I got] tritium from bow-and-arrow sights, polonium from electrostatic film brushes, americium from smoke detectors, radium from, of course, radium dials.”

But, writes Silverstein, what Hahn really wanted was uranium 235, because it would provide the “biggest reaction.” His first approach was to drive hundreds of miles through northern Michigan with a Geiger counter on his dashboard. The search yielded only a few rocks of pitchblende (which contains minuscule amounts of uranium 235), so he decided to go back to his friends at the NRC for help. His contacts at the regulatory commission gave him the address of a Czechoslovakian firm that sells uranium to commercial buyers. That contact resulted in a few more samples of pitchblende. His attempts to isolate and purify the uranium, however, resulted in little more than a small pile of black powder.

Armed with his radioactive cocktail–and a sketch of a checkerboard breeder reactor from one of his father's college textbooks–Hahn began devising his backyard breeder. He knew that it took at least 30 pounds of enriched uranium–vastly beyond anything he had–to initiate a chain reaction, but he thought he could at least generate some interesting results. “No matter what happened,” he told Silver-stein, “there would be something changing into something–some kind of reaction going on there.”

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“Keep your hands where I can see them.”

His makeshift reactor had a “core” of radium, americium, and beryllium that was wrapped in a “blanket” of thorium ash and uranium powder. And it produced. “The level of radiation after a few weeks was far greater than it was at assembly,” he recounted. “I know I transformed some radioactive materials.”

When his Geiger counter began picking up radiation several doors down from his house, Hahn decided that he had “too much radioactive stuff in one place,” and he disassembled the “reactor.” By the time the EPA showed up, he had hidden most of the radioactive materials, including the purified thorium pellets, leaving only the radium and americium behind. “The funny thing is,” he joked to Silverstein, “they only got the garbage, and the garbage got all the good stuff.”

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The “garbage” was enough to scare the EPA, which spent $60,000 on the Golf Manor Superfund clean-up. And, according to CBS This Morning, the agency “never sent a bill.”

–Michael Flynn

In brief

▪ Hacking and hoaxing

Information warfare, says George Smith, writing in the Fall 1998 Issues in Science and Technology, has been vastly overrated. Smith, who edits the Crypt Newsletter, points out that the FBI's seminal article, “Computer Crime: An Emerging Challenge for Law Enforcement,” relied heavily on reports of a computer virus called “Clinton.” But there was no such virus–it and other viruses cited in the fbi article had come from an April Fool's Day column in a computer magazine. Similarly, Smith points out that the Defense Information Systems Agency (disa) says there were 250,000 intrusions by hackers into Defense Department computers in 1995. But this figure is an illusion. Disa received reports of some 500 actual “incidents,” but decided arbitrarily that only 0.2 percent of cases were reported. Therefore, disa “multiplied [actual incidents] by 500 and came up with 250,000.”

▪ And the grand prize winner is …

The 1998 “Ig Nobel” award ceremony held its annual “win-a-date-with-a-Nobel-laureate” contest. And Ig Nobels were awarded to the usual suspects, like Richard Seed of human cloning fame and Peter Fong, who studied the effects of Prozac on clams (they died happy, he says). But what made the October 8, 1998 parody of the Nobels unusual was that for the first time in Ig Nobel history an award winner was recognized for the second time. Jacques Benveniste, a French researcher, had earlier earned the prize for claiming that water “remembers” biological molecules that it has once been associated with. He won again this year for his claim that those memories can be digitally encoded and transferred over telephone lines.

▪ Recycling pays

Remember the Superconducting Super Collider? That giant science project that ended up as an enormous and expensive hole in the ground near Waxahachie, Texas? A small company called International Isotopes, Inc., bought the project's buildings, linear accelerator, and 14.5 miles of tunnels at a distress-sale price–$3.3 million (Chemical & Engineering News, September 21, 1998). With these purchases, International Isotopes is set to become the leader in the production of isotopes for nuclear medicine: With twice the energy of other commercially owned cyclotrons, the linear accelerator can irradiate five times as many targets. It can also produce the rare research isotopes that lower-energy cyclotrons cannot make.

▪ Kyoto treaty a dirty deal?

Every time someone mentions clean air or unpolluted streams, the U.S. military gets a bit edgy. And just as the Pentagon used the Persian Gulf War as an excuse to ask for an exemption from U.S. environmental regulations, the military has now asked to be excused from any international agreements aimed at reducing human-caused global warming. H. Sterling Burnett, writing in Investor's Business Daily (October 15, 1998), believes a military exemption is critical to U.S. national security. Burnett points out that the federal government is the largest U.S. consumer of energy (between three and seven percent, by some estimates), and 73 percent of the energy the government uses is consumed by the Defense Department. Burnett apparently believes that none of this energy is wasted; he complains that the United States must either reduce the size of its military, admit that it will violate the treaty in an emergency, or ask the private sector to reduce emissions more sharply. (Others might ask: Why not do all three?)

▪ Titaniacs

A lot of people think the sunken ocean liner Titanic should remain undisturbed on the ocean floor. And a U.S. court has ruled that only the U.S. company RMS Titanic has the rights to take pictures of the wreck. But Russia's Oceanology Institute, starved for cash, has apparently been using the Academician Mstislav Keldysh and two Russian bathyscaphes (Mir 1 and Mir 2) to deliver tourists three kilometers down to view–and supposedly, take snapshots of–the remains of the famous ship (Nature, October 1, 1998). The Russians refer to the tourists, who pay Deep Ocean Expeditions, a British company, $32,500 each, as “scientific observers.”

▪ Embracing Darwin

Britain's Health and Safety Executive has concluded that for years the agency was “too trusting” of Britain's Atomic Energy Agency (UKAEA) (New Scientist, September 12, 1998). After completing a comprehensive safety audit at the fault-plagued Dounreay nuclear complex on Scotland's northern coast, Laurence Williams, the agency's chief inspector, recommended 143 changes at the site–including doing something about the partitions meant to separate contaminated areas at Dounreay's uranium processing plant, which he described as “held together with adhesive tape.” The UKAEA's response to criticism was that “safety is a continually evolving process.”

▪ Making waves

Everything from advanced civil aviation systems to fancy new autos with on-board computers now use Global Positioning System (GPS) signals from satellites to pinpoint locations. But the Defense Department–arguing that national security demands that only the military get the most accurate information–has steadfastly refused to share its GPS signals: Civilian receivers get a less accurate, deliberately degraded message–a practice that has prevented important potential users like the FAA from taking full advantage of the system. As a result, civilian users have devised an ingenious series of “work-arounds” that increase the accuracy of the degraded signal. The latest–and best–appears to be the brainchild of Paul Cross, a researcher at University College London, who recently developed a method that relies on carrier waves instead of timing signals. According to New Scientist, Cross's method not only corrects the deliberate errors in the civilian signal, it is more accurate than the military signal itself.

20 years ago in the Bulletin

Edward Teller's X-ray laser was the dream weapon of the Star Wars missile defense crowd in the 1980s. But after nearly five years of false starts and overstated promises, the laser program was terminated in 1987.

This was not the first time that ICBM-destroying beam weapons had captured the imagination of the U.S. defense establishment. In May 1977, Aviation Week and Space Technology published an article by Gen. George Keegan in which he claimed that the Soviet Union had been working on an anti-ballistic missile particle beam for 20 years, and that it might be ready to deploy it.

Not everyone agreed with the general's assessment. In November 1978, Richard L. Garwin, a physicist at IBM and an adviser to the government on weapons-related matters, was interviewed by Harry Reasoner of 60 Minutes as part of a story on the purported Soviet super beam. In the interview, Garwin explained that it would be “a disservice to suggest that the [particle beam] will be an effective system.” He added: “If [the Soviet Union has been] working on it for 20 years, they've been doing it very slowly and not very effectively.”

60 Minutes, however, cut most of the interview and instead broadcast only two brief comments from the physicist. Upset with the show's treatment of the particle-beam issue, Garwin wrote a letter to Don Hewitt, executive producer of 60 Minutes, which was published along with the texts of the original and the abridged versions of the interview in the February 1979 Bulletin.

Garwin explained in the letter that the reasons why the “particle beam is not practical” were clearly “stated in his interview.” And he asked “whose decision was it not to show a single substantive comment as to why the particle beam need not be feared as a means of ‘eviscerating’ our strategic deterrence?”

One of Garwin's comments that made it into the program had been a response to Reasoner's suggestion that there was a “split between fully qualified scientists” regarding the Soviet weapon. Garwin responded, “I doubt it. I think most of the scientists with contact with this field would agree with me. … All the old boys are against it, and only the young Turks are in favor.”

At that point in the broadcast, Reasoner turned to another authority: “One scientist who may with respect be called an ‘old boy’ is Dr. Edward Teller.”

One supposes that Dr. Teller was already dreaming of Star Wars.