X-Ray Specs
A lot of promises are made in the bedroom and on the campaign trail, but the biggest, most important promises are made in tiny print on the last few pages of comic books—like the promise of glasses that let you see through things. For a modest price these advertisements guarantee the Superman-like ability to see through walls; but honestly, X-ray spectacles were really all about seeing through clothes. The "scientific marvel of the century" offered in comic books may be a gimmick, but modern defense contractors are not playing around.
Visible light insists on bouncing off even the flimsiest nontransparent objects. An X-ray is like visible light except that it has more energy. High-energy photons (which are invisible to our eyes) tend to penetrate farther into objects before they bounce off—or they can go all the way through. To develop X-ray spectacles, the trick is to use light with just enough power to penetrate clothing but not enough to penetrate skin. Because let's face it, no matter what the fashion magazines say, walking skeletons are just not that sexy.
The need for better airport security led to the development of a new backscatter machine that uses low-power X-rays with just the right finesse—they penetrate clothing but not skin. Specifically, the machine emits and measures the position of X-rays that "scatter back" from a person and generate a photograph-quality image. The process is sometimes referred to by the vaguely disgusting term "backscatting." Very dense objects (like guns) show up dark,
medium-dense objects (like skin) come out grayscale, and not-very-dense objects (like clothes) don't show up at all. To summarize, it's a magical machine that spits out naked images of fully clothed people. But a backscatter machine won't fit on your face; it's the size of a refrigerator and takes about eight seconds to scan a person standing about eight inches away.
When X-ray eyes leave the realm of gimmicks and enter the
local airport, privacy becomes an issue. Who should wield such awesome power? Though backscatter devices are commonly used in prisons, diamond mines, and customs searches, introducing the machines to airports has been a tough sell. Critics warn against bombarding children and adults with X-rays, even low-power X-rays. Meanwhile, the CEO of an X-ray machine company cheerfully reports that radiation levels are similar to that of good, clean sunlight. The American Civil Liberties Union describes the process as a "virtual strip search." Travelers in the United Kingdom, however, are unfazed; virtual strip search machines have been used at London's Heathrow Airport for years.
Gawking at naked people is always good fun, but what about using your abilities for the forces of good? Superman used his X-ray vision to see through walls in an endless, obsessive search for truth and justice. Now lowly humans can do the same using the Radar Scope. Research funded by DARPA recently produced the device, which is the size of a telephone handset and can sense human beings through up to 12 inches of concrete. The "through-wall personnel detector" uses radar to sense movements as small as breathing up to 50 feet into the next room. Put simply, it is a motion detector that works through walls.
Whether your goal is to see through walls or bikinis, the technology is here. And unlike the swirly sunglasses that disappointed so many of us, these gadgets actually work. Finally, humankind has mastered the power of light and put it to a noble purpose. For around a thousand dollars, you can buy a Radar Scope and dominate future games of hide-and-seek, but at a reported cost of six figures, backscatter portals are likely to be out of the reach of most comic-book readers.
Smart House
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Nursebot is intended to remind the |
Since the beginning of time, children have performed all the duties of a so-called smart home: grabbing beers from fridges, changing television channels, and taking verbal abuse for problems they don't understand and probably didn't cause. Considering that children have been around forever, it is only reasonable to expect that a better technology exists by now. Certainly, we should all be living in robotic houses that act as conscious, living servants to meet our every need and desire.
Right now, "smart home" technology is available off the shelf; home automation enthusiasts have access to all kinds of gadgets that can make life simpler (and more complicated). The key goal for home automation is to give the occupant total control over the house from anywhere. Most home automation devices require a central personal computer to provide control and to run programs. For instance, X10 modules plug into the wall and then communicate with a home computer, letting a person turn on and off lights and appliances via a Web site. There are quite a few sensors, such as cameras, motion detectors, or water leak detectors, that can be used to monitor who is in your driveway, trigger exterior lights when people approach, or constantly check for broken water pipes. Meanwhile, effectors can be used to water plants automatically, remotely raise and lower blinds, or feed your pets. Anyone can create the ultimate remote-control house—the only limit is your wallet.
Sadly, fetching your beer is not a priority for smart homes. Instead, the most promising application is to help elderly people live safely and independently. Smart homes are being designed to use simple sensors common to home security systems and advanced artificial intelligence in order to figure out what people are doing (activity recognition) and where they are (location estimation). The Georgia Tech Aware Home looks like a two-story house but is in reality a laboratory bristling with sensing equipment, including cameras in the ceiling, microphones in the walls, and invisible trip sensors in doorways. The Aware Home and other laboratories like it are the very first prototype smart homes that will help us all stay out of the nursing home someday.
If you are frightened by disembodied voices that emanate from speakers in the walls, then you may want to complement your smart home with a mobile robot. In an experiment with Nursebot (a trashcan-size wheeled robot designed to deliver medicine and reminders) at Carnegie Mellon University, researchers found that by using a laser range finder, a robotic home could correctly predict the paths that people commonly take so that mobile robots could learn to stay out of the way. Nursebot can use such knowledge to effectively cater to occupants. She even has grab bars so that elderly users can grab hold and stand up. Beat that, Rascal Scooter!
Ray Gun
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The Active Denial system is the Pentagon's |
Ray-gun-like weapons are quickly becoming commonplace. Preliminary weapons are nonlethal and have been used by happy-go-lucky military troops and police officers eager to teach new dance moves to protesters and rioters. Several classes of directed energy weapons, called nonkinetic weapons by military types, have met field trials and are coming into widespread use.
The Active Denial System, developed by the Pentagon, can aim and emit superhigh-frequency microwaves. When the millimeter-size wave pulses hit human skin, they heat the body's water to the point of pain. The burning sensation has been compared to touching a hundred-watt lightbulb but without the singed hair—the system is only playing with your nerve endings, not causing permanent damage. Currently, the weapon won't fit in your holster—soldiers have to mount them on top of Humvees.
Alternately, why not use a prototype "lightning gun" to harness the Zeus-like power of electricity? A host of new defense contractors have sprouted to help governments battle terrorists, and they supply a variety of hair-raising weapons. Companies like Ionatron and Xtreme Alternative Defense Systems have developed competing zap guns. Both weapons use pulsed lasers to create a conductive path in the air away from the gun's barrel and then use a simple Tesla coil to generate a painful bolt of electricity. Both rifles are the size of a briefcase, weigh 25 pounds, and can shoot electricity wildly at 12 feet or consistently at 4 feet. Occasionally, the flashing purple discharge kicks back and lashes the bejesus out of the poor guy holding the gun.
We have so far ignored the most compelling directed energy weapon of all—the laser blaster. Jedi Knights can apparently use light sabers to easily deflect laser bolts, but electrically driven solid-state laser weapons (preferred over their less-wieldy chemical-based cousins) are designed primarily to zap approaching missiles. Field-tested military prototypes are pushing 25 kilowatts of power, and research is under way on versions that can turn missiles into swiss cheese with 100 kilowatts of laser power (a million times more powerful than an everyday laser pointer).
Meanwhile, the General Atomics company has developed a prototype weapon, called the High Energy Liquid Laser Area Defense System (HELLADS). Precise details are classified, but the system purportedly combines two types of laser, liquid and solid-state, for a single über-powerful weapon. Unlike other liquid lasers, the HELLADS can fire a continuous beam without a large cooling system, and unlike solid-state lasers, the HELLADS produces a high-energy density that does not require pulsing the laser on and off. The whole system weighs 1,600 pounds and can fit into the space of a large refrigerator. The project goal is to eventually spit a 150-kilowatt beam clean through enemy missiles.
The big question, of course, is what is keeping a handheld laser blaster out of your pocket? The most noticeable obstacle is heat dissipation. Operational lasers are inefficient, converting only about 15 percent of electric power into laser, with the rest wasted in the form of extreme heat. More efficient diodes (the part that converts electricity to light) would lower heat output and shrink lasers so that they could hang jauntily on your hip. For now, though, you will have to be happy with mounting military lasers to your tactical ground vehicle (that's your Buick).
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This article is excerpted from Where's My Jetpack? A Guide to the Amazing Science Fiction Future That Never Arrived, to be published in April 2007. Copyright 2007 by Daniel H. Wilson, Ph.D. Printed by arrangement with Bloomsbury USA.
