Zapped

by Bob Berman

  Nobody foresaw how quickly this invention would enter our daily lives and how ubiquitous it would become. It changed everything from how we shop for groceries to how we listen to music. Nor could anybody have predicted how inexpensive it would become—and how quickly it would do so. In a mere fourteen years, the Universal Product Code, with its black bars separated by varying spaces, which convert a laser reflection into on-and-off signals that produce a twelve-digit numerical code readable by a computer, had been created. The National Cash Register Company installed a test bar-code system at the Marsh Supermarket in Troy, Ohio, near its factory producing the equipment. On June 26, 1974, at 8:01 a.m., shopper Clyde Dawson pulled a ten-pack of Wrigley’s Juicy Fruit gum out of his basket, and it was scanned by cashier Sharon Buchanan. This was the first commercial use of the UPC. The pack of gum and the receipt are now on display in Washington’s Smithsonian Institution.

  Supermarket lasers, like those in CD players, use around five milliwatts (mw) of energy, which is also the legal limit for handheld laser devices such as presentation pointers. Lasers in DVD players use up to 10 mw, and DVD burners require 100 mw. In all these cases, laser reflections from the spinning disk’s tiny flat areas, called lands, combined with the absence of reflection from deeper “pits,” produces a rapid succession of laser pulses, a code that the built-in computer chip converts to digital information that is then translated into images and sounds. Lasers used in surgery, on the other hand, don’t create coded information. Instead the goal is simply to use its sharply concentrated heat. Laser scalpels employ 30,000 to 100,000 mw of energy, meaning 30 to 100 watts, to effortlessly cut through flesh.

  Everyday five-milliwat red lasers used for pointers and cat toys are the least expensive, at a few dollars apiece. These, however, do not create a visible beam in the night sky. That’s because their emissions can’t illuminate airborne dust or tiny water drops that in turn reflect light back to the user’s eyes.

  To produce a visible ray, you need a green laser or one of the newer blue or violet lasers that allow reflection off airborne particulates such as pollen and dust. Because green is perceived far more readily than any other color, it’s the only one that can create a visible beam using just the legal 5 mw of energy. (“Legal” because it’s the maximum output the government allows for a handheld laser. As of 2017, however, more powerful devices can still be purchased online.) But in bright moonlight or in light-polluted cities, a 30 mw or higher green laser is the best way to create a nice visible beam. Available from specialty websites, many in China, they inhabit a quasilegal niche. But even the unambiguously legal 5 mw lasers are inherently dangerous if pointed at an eye. Laser light is so concentrated that it can produce eye damage in a fraction of a second.

  Since 2007 or so, an increasing number of young people are buying superboosted 20 mw, 50 mw, and even 100 mw lasers. These are fabulous tools for showing off constellations, and companies such as Wicked Lasers, exploiting the popularity of the lightsaber battles seen in Star Wars movies, produce ever-more-powerful models with teen-friendly names like Spyder and Krypton. I’ve tried several of these. One was a 1,000 mw model—a full watt! Point one of these at a dark-color balloon, and it will pop almost instantly. But their reflections off glass or chrome surfaces are dangerous to look at. These handheld devices are available on the Internet for $300 or so.

  At night, without much thought to the consequences, some people point them at passing planes. Inside the cockpit, pilots are suddenly incapacitated—totally blinded for several seconds. Sometimes the pilot cannot continue his or her duties because the resulting headache and dizziness persist for hours. No one has yet been permanently blinded, but with lasers getting increasingly powerful, it may only be a matter of time before this happens.

  In 2012, President Obama established a penalty of five years in prison for the offense of pointing a laser at a plane. Soon afterward, one California man received a sentence of fourteen years because of his “willfulness” in repeatedly zapping helicopters.

  Scanning bar codes and playing at lightsabers is all very well. But what about actual, real-life directed-energy weapons? They’ve gone from sci-fi fantasy to reality. The US military continues to develop ultrapowerful laser weapons using the invisible sections of the spectrum.

  During World War II, British scientists tried to focus microwaves—which were already successfully used in radar and would later be used in microwave ovens—into a sort of death-ray gun, but it never panned out.

  A version of a microwave-beam weapon appears in a 2006 sci-fi book, Blindsight by Peter Watts, along with the popular misconception that microwaves cook flesh from the inside out. (Microwave ovens cook food all at once—the inside and outside simultaneously, albeit with some unevenness—see here.) But actual focused microwave weapons have indeed been developed and deployed by the US military. The army version, which uses a parabolic dish on a Jeep-like vehicle, can create heat in organic targets, but this has been fairly ineffective in practice. Sometimes target victims have reported a sensation of increased warmth. Despite much publicity about expensive but failed laser antiballistic missile systems, more modest systems have become a reality.

  In 2014, LaWS (the Laser Weapon System) went into operational status aboard a US naval vessel. This ship-defense system uses a thirty-thousand-watt infrared laser from a solid-state array and has successfully shot down and crippled incoming test targets. It was also able to render a small approaching boat’s engines inoperative.

  Even the most powerful lasers, which can quickly melt holes in metal objects, are limited in their effectiveness by atmospheric scattering. They also have difficulty keeping a quickly moving target, such as a missile, precisely centered in their sights. Nonetheless, current truck-mounted high-energy laser cannons can reportedly shoot down aircraft.

  The latest lasers supposedly use powerful magnetic fields to boost the speed of electrons, which then transfer energy to the laser’s photon beams. As of 2016, these are too bulky to be employed as handheld or even truck-mounted weapons, but research and development continue.

  Now that we know how invisible-beam armaments have progressed, it’s easy to answer those who imagine there are effective current ray-gun weapons in the world’s military arsenal. On the Web, some people paranoiacally argue that the smoke and dust that radiated from the World Trade Center buildings as they collapsed is proof that they were destroyed by secret US military ray guns. When an educated friend actually said that to me, I was mystified.

  “What part of the electromagnetic spectrum would this ray gun be using?” I asked. An energy ray is made up of electromagnetism; there is no other kind of focusable energy except a sonic or sound-producing device. It takes only a few moments to consider the entire electromagnetic spectrum. Such a weapon couldn’t use gamma rays or X-rays—these don’t harm concrete and metal. Nor could it use ultraviolet rays, which would similarly cause no damage at all. It couldn’t use visible light, because that’s harmless, too—not to mention that no sudden brightness was observed just before the buildings collapsed.

  A ray gun couldn’t use radio waves, including microwaves, because no matter how intense they are they cannot make concrete disintegrate. That leaves infrared radiation—heat. A theoretical unlimited-power focused heat ray could indeed melt steel. But any building shot by such a ray would first glow red, then white, before it melted. And it would radiate enough heat to cook all the pedestrians on the surrounding streets. Bottom line: no invisible-electromagnetic-ray weapon could cause buildings to collapse into smoke and dust—all without creating any heat.

  Ray guns remain in the realm of sci-fi for now. But knowledge of invisible light helps us understand the nature of all invisible beams, including potential weapons. Thus far, directed-energy weapons sound a lot scarier than they’ve proved to be in actuality.

  And FYI: if you were attacked by any kind of light-beam weapon, whether it uses visible light (“photon torpedoes”) or invisible rays (“microwave canno
ns”), you’d never see the beam approaching. So those movies in which our hero weaves and ducks his spacecraft to avoid incoming photon torpedoes—forget it. You would have no advance notice of something approaching at light speed. You couldn’t see a light beam or a photon torpedo (an intense cluster of energy) before it arrives, because its image is the weapon. Just a little something to keep in mind the next time you watch Star Wars.

  CHAPTER 23

  The Next Frontier: Zero-Point and Dark Energies

  Our quest has been to explore the unseen energies that pervade our universe, our planet, and our bodies. We’ve seen that the word energy usually refers to waves on the electromagnetic spectrum. But since 1948, science has slowly awakened to an unexpected reality: some other superpower not only lurks everywhere, it may also dwarf all other energies combined.

  Ah, for the good old days, when vacuum meant “nothing.”

  Those days are gone forever. We now have reason to believe that the universe’s vast tracts of emptiness seethe with unimaginable power.

  In a way, it all starts with the ancient Greeks, who hated the notion of a vacuum. Their argument was semantic, stemming from their love of logic. How could there be a vacuum, they reasoned, when the words be and vacuum are contradictory? If a vacuum is nothingness, well, there can’t be nothing.

  Those silly Greeks, we all thought back in the 1960s, when I first studied physics in college. Of course you can create a vacuum. Just evacuate all the air out of a bell jar, every last molecule, and voilà. Our laboratory vacuums still had a few molecules in them; they weren’t perfect vacuums, but so what? That hardly mattered, because the basic premise, which is that nothingness is real, seemingly remained valid.

  Turns out that the Greeks were right. First, no matter how good the vacuum, its space is still penetrated by some heat, in the form of infrared radiation and microwaves, emanating from the vacuum’s walls or its environment. Because energy and mass are fundamentally the same, those waves zipping through all of space ensure that you can’t ever have a true vacuum.

  But that’s small potatoes compared to Werner Heisenberg’s uncertainty principle, which says that a vacuum shouldn’t actually exist. He was quickly followed by other theorists who argued that the vacuum of space should be filled with a bizarre sort of quantum energy.

  They were right, too. Much experimental evidence shows that virtual particles—things like electrons and antimatter positrons, which are electrons with their electrical charges reversed—snap, crackle, and pop out of nothingness everywhere all the time. Each particle typically exists for just a billionth of a trillionth of a second, then vanishes. If there’s an energy field around, a subatomic particle can use some of the energy to remain in existence forever. Thus things perpetually spring to life out of that quantum vacuum.

  Most physicists now believe that this underlying “quantum foam” pervades the cosmos. It’s everywhere, and its power is unimaginable. Estimates of the power in each small bit of seemingly empty space vary enormously. But it’s possible, perhaps likely, that the apparent nothingness within an empty coffee cup held by an astronaut in the virtual vacuum of space contains enough energy to instantly boil away all the earth’s oceans.

  Wait a second. I’m from Missouri. Prove it to me.

  Okay, consider the Casimir effect. It was named for the Dutch physicist who first predicted it in 1948. He said that if you suspend two copper plates very close to each other—a millionth of an inch apart—the quantum energy between the plates would suffer a limitation: its waves wouldn’t have enough space in which to flow, just as microwaves are physically too big to fit through those little holes in the screen in your microwave oven’s door. But the quantum energy outside the two plates would be as strong as ever, so it would push the plates together—hard. Well, this really happens. The Casimir effect is real.

  Some dreamers think of exploiting “vacuum energy” to give the world unlimited power. But there’s a problem. This energy exists everywhere equally, which is why we don’t sense it or detect it. Energy only flows from a place of greater energy to a place of lesser energy. So how would you set up a condition that had less energy than everything around you? How could you make it come to you?

  The only way to do that is to chill matter to absolute zero, at minus 459.67 degrees Fahrenheit, the point where all molecular motion stops. Then and only then are things at parity with this all-pervasive power, which is why it’s also called zero-point energy. That’s where this hidden fount of energy becomes evident: why else would helium still be liquid at absolute zero if it weren’t receiving a bit of energy that keeps it from freezing solid?

  In short, zero-point energy does show itself when all other energy is absent.

  But in order to get this limitless quantum-foam energy to flow to you, you’d have to somehow create below-absolute-zero conditions. You’d have to make molecules move more slowly than “stopped.”

  More slowly than stopped? How do you do that?

  If you have any ideas, we’re all ears.

  In the meantime, imagine that the seeming emptiness of space is not just permeated by unseen particles such as neutrinos, unseen magnetic and electric fields, and unseen waves of microwave energy, infrared radiation, and the like. It is also permeated by unimaginable power. Because we’re barely in our infancy when it comes to recognizing the existence of zero-point energy, we can’t say what it may or may not do to us. For the moment, visualize what you can see as being a thin, almost inconsequential surface scum that overlies this lively three-dimensional energy.

  We can’t see or feel all the invisible energy that surrounds us because there’d be no biological advantage to that. Why perceive a blindingly powerful energy that’s equally present everywhere? Perhaps if we could fast-forward to a point in time one hundred years from now, we’d find that our technology’s obliviousness to this zero-point energy seems as primitive as the attitude of the eighteenth-century scientists who didn’t lift a finger to try to exploit electricity.

  Still, file zero-point energy away somewhere under “most powerful entity of all.” Surely as technology and our understanding of it improve, we humans will not ignore vacuum energy forever.

  Beyond zero-point energy, there are other mysterious, newly discovered energies in the universe. The existence of vacuum energy had been theorized in the 1930s, and solid evidence for it started to emerge in 1948. But a much more recent development uncovered the apparent existence of something else entirely, which we call dark energy. Until 1998 it was an unknown, and indeed no one had even hypothesized its existence. It was one of the most unexpected discoveries in the history of science, right up there with William Herschel stumbling upon the planet Uranus.

  You see, we’d been observing the expanding universe since the late 1920s. All observations seemed to show that the cosmos started explosively expanding 13.8 billion years ago and has been steadily slowing down ever since.

  Cosmic deceleration made perfect sense. Gravity from every individual galaxy pulls on all others. Logically, the outrush should be continuously diminishing, just as it does when you let go of a stretched-out rubber band. The big question was whether it would someday come to a stop. Then perhaps the universe might go the other way and get smaller. To find out whether this was indeed happening was the scientific holy grail of the 1980s and the 1990s. Everyone was looking for the deceleration parameter—the exact rate at which the cosmos’s expansion was supposedly slowing down.

  Measuring galaxies’ radial velocity, their recessional speed, was the easy part; it could be done simply by using the famous Doppler redshift. But this required that we also know their exact distance from us. In the late 1990s two teams of astronomers studied a particular type of supernova, type 1a, whose brightness was believed to always have the same intensity. They used these supernovae as “standard candles” to determine the distances between the thousands of galaxies in which they erupted. When the data came in, it threw everyone for a loop. It turned out that t
he universe’s expansion was not slowing down at all. When the smoke cleared, a new picture suddenly emerged. Unfortunately, it told a story that made no sense.

  It seems that for the first half of the universe’s life, its expansion did slow down. But then, around seven billion years ago, all galaxy clusters started speeding up. Since then the expansion has gotten more animated. There’s no end in sight to this bewildering acceleration.

  What could have made galaxy clusters suddenly move away from one another with increasing speed? Could they have had enormous rocket engines on them that fired in unison when the universe was half its present age? What could possibly be happening?

  Out of desperation, physicists coined a new term—dark energy—to describe a kind of antigravity force that pervades the cosmos by lurking within empty space itself. Presumably, in the early eons of the universe, things were so crowded that gravity overcame the outward push of dark energy. But when the cosmos became empty enough, the antigravity property of empty space started assuming command. From that point on, the inherent repelling nature of space was enough to overcome gravity and dominate the cosmos, making everything expand like an over-yeasted bakery roll.

  So dark energy fills the entirety of empty space and was perhaps the impetus for the big bang in the first place. If so, the universe is still banging. Nonetheless, nobody knows anything about what dark energy really is, except that it has antigravity power.

  For those who tend to worry about things and are not content to fret about blood pressure and cholesterol, this runaway expansion may seem depressing. It seems to point to an ever-lonelier universe, with a future of ever-greater spaces yawning between galaxies. Of course, since we know nothing about dark energy, including how it arose, we can’t say whether it’s permanent or even whether it may someday reverse itself.