by Bob Berman
• theta waves (4–7 Hz), which are associated with sleep as well but are also observed during deep relaxation and meditation.
All these waves are weak by any measure. Whereas the earth’s magnetic field can barely swivel a compass needle, brain signals are a billionth of that strength.
But the term brain waves is a bit misleading because it makes people think of the brain as a kind of radio transmitter. In reality, human brain waves are not really electromagnetic waves at all—the kind transmitted from one place to another, as infrared radiation and microwaves are. Rather, they are changes in the electrical field. They are pulses, or rhythms, in the brain’s electrical functioning—patterns that very much correlate with forms of mental activity. The electrodes attached to your skull can measure that electrical field, and the “waves” are just an interpretation of the patterns observed when these weak electrical pulses are plotted. But no one has ever detected waves being transmitted from one mind to another. Indeed, nothing ever travels from a brain to a point outside it.
When measured atop the skull, the changes in the skin’s electrical field, caused by neuron firings an inch or more below it, are minuscule. Think of the waves as a reflection of the ability of an electrical force to do work—to budge a charged particle, say—rather than as forces radiating into space. However, when researchers use special helmets and signal-boosting techniques such as chilling the sensors to a point near absolute zero, and when they work in a metal-clad room where all extraneous electromagnetic activity is kept outside, electrical disturbances, visualized as wave patterns, have been detected a few inches away from the sensors. But again, they’re electrical firings, not electromagnetic transmissions.
Discussing invisible energy emanating from our brains can quickly take us into quackery and New Age supposition. Actual laboratory studies looking for ESP, or thought transference, have been carried out for decades and are consistently disappointing in that they routinely come up with negative results. Some such experiments have been performed at prestigious universities; others have been wacky. One of the most famous was the effort by astronaut Edgar Mitchell during the Apollo 14 mission, in 1971.
Mitchell, who died at the age of eighty-five in 2016, did a very strange thing that was not authorized by anyone in mission control. By prearrangement with four people back on earth, he used his own leisure “off time” during the mission to perform ESP experiments involving a series of twenty-five cards printed with Zener symbols—a circle, a cross, a set of waves, a square, and a star.* The idea was to see if mental telepathy could work between the earth and another celestial body. The result? This depends on whom you ask.
The idea was for subjects to choose the correct sequence of cards Mitchell was looking at. Because forty correct hits out of two hundred tries would be expected by chance, and three of the four subjects scored lower than this—only the final subject scored higher, with fifty-one out of two hundred correct—no objective scientist would declare this anything but a random result, a failure to demonstrate ESP. Moreover, the launch’s forty-minute delay meant that all four subjects, who had been coached to expect ESP transmissions at a specific time during the mission but who were unaware of the delay, were attempting to receive Mitchell’s thoughts at the wrong time, when he wasn’t even “sending” them.
None of that seemed to faze Mitchell, who devoted much of his post-Apollo life to psychic research. In his analysis, he characterized the results of his ESP experiment as “statistically highly significant.” Indeed, he eventually explained that “the well-known experiment in the laboratory was to use cards with the five Zener symbols, but the actual cards aren’t important. It was easier for me to use random number tables than carry the physical cards. Instead, all I did was to generate four tables of 25 random numbers just using the numbers 1 to 5. Then I randomly assigned a Zener symbol to each number. For each transmission, I would then check the particular table of random numbers and think about the corresponding symbol for 15 seconds. Each transmission took about 6 minutes.” At any rate, Mitchell kept the entire project secret from both NASA and his crewmates. He later explained that NASA’s feelings about such psychic research was “totally negative, totally closed”—an appraisal that surprised no one.
Science not only fails to provide empirical support for the theory of extrasensory perception, it also offers an excellent explanation for anecdotal ESP events that do seem to work. The reasoning goes like this:
Say you’re thinking of a particular old friend, and just then the phone rings, and it’s the friend you were thinking of. You might ascribe it to telepathy and share that with her (“You read my mind!”). We all notice and remember whenever such a remarkable coincidence happens because it’s so dramatic. Yet how many times do we idly think about lots of other people who do not call at that moment? We don’t even give those nonevents a second thought, let alone remember them. Thus we experience bias selection—that is, we recall only those times when ESP is supposedly at play.
Bias selection is a good explanation for the apparent instances of ESP most of us have experienced in life. It’s hard to rebut. Yet according to Gallup polls, between 50 and 60 percent of respondents think that “some people possess psychic powers or ESP.” How do we account for that? Is it mere gullibility? Even dismissing the stubborn minority who are chronically naive or antiscience (in 2001, 30 percent of National Science Foundation survey respondents thought that “some of the unidentified flying objects that have been reported are really space vehicles from other civilizations”), we’re still left with a substantial number of people who think that mind reading is real.
In truth, while all manner of New Age psychic nonsense has been adequately discredited, there still remains a possibility that our minds really can interact with those of others. Perhaps we are linked more deeply than we know: the mysterious workings of the brain might be capable of connections that transcend today’s known modalities. Here are a few examples that, for me, at least, make it hard to completely rule out this possibility.
In the first instance, I was playing Scrabble with a friend, waiting for her to finish her turn. Staring idly at the board, I suddenly and vividly saw, in my mind’s eye, her hand coming down and placing an I in front of an existing T on the board to make the two-point word it.
A couple of seconds later, she did exactly that—even though it was a most unlikely play. (What Scrabble player would ever squander a turn for a measly two points?) Startled, I asked her if she had visualized making that word a few seconds before she actually did it, and she said yes. So I’d apparently seen it in my mind at the same time as she did. Advance perception of such an unlikely event in two different people, at the exact same moment in time, seems too improbable to dismiss as bias selection.
In the second instance, two close friends of mine who are identical twins are both seriously into music and singing; each was in his college’s choir. Throughout their lives, they both insist, one twin would have a song playing in his head when suddenly the other twin would start to sing it, beginning in the exact same place in the tune and in the same key!
Another identical twin told me an interesting story about something that happened when she and her sister were teenagers: “When we were seventeen, my sister went to live in Mexico for six months while I went to live in the South of France. When we got back we figured out that each of us had translated a song from the cartoon movie An American Tail—“There Are No Cats in America”—into the local language, then had it stuck in our heads for months.”
The coincidence explanation sounds unconvincing in cases like these. Obviously some satisfactory mechanism must be found to explain such strangely synchronous human events.
Okay, I know what you’re thinking (ha!). Those were identical twins, who may live in a world apart from the rest of us. But still. I will ask skeptical readers to forgive me here, but I simply cannot fully dismiss the possibility of ESP, even if it seems incapable of replication in controlled laboratory setti
ngs. Anyway, if it is real, the explanation may indeed involve certain brain waves that can march in sync with others. Because electrical pulses are always accompanied by electromagnetic wave activity (recall that Hertz found radio waves by noticing sparks across gaps), perhaps ESP also works along these lines.
Belief in ESP appears to have remained steady over the decades. According to a 2002 CBS News poll, a majority of Americans—57 percent—believe in ESP, or telepathy. But despite this, only a small number say they’ve actually had such an experience themselves. Some interesting demographic differences also came to light. Americans age sixty-five and older are most skeptical about ESP, telepathy, and other similar experiences. Thirty-two to 47 percent of people in that age group do not believe in it. But 31 to 67 percent of people younger than sixty-five think that people can sometimes perceive the thoughts of another. Interestingly, those with at least some college education are more likely to believe in ESP.
Except, perhaps, for the discussion about the effects of microwaves on human health, this must be the only chapter in this book in which I allow that evidence concerning the putative consequences of invisible rays is inconclusive. When it comes to the mind’s unseen energies, you are not discouraged from healthy skepticism.
CHAPTER 22
Ray Guns
Deadly beams from handheld or spaceship-mounted armaments have been sci-fi staples since forever. What Star Wars or Star Trek movie would be complete without directed-energy weapons—things like laser cannons and tractor beams?
The idea of an energy ray used in warfare probably dates to its supposed employment by the ancient Greeks. The singular event was a dramatic battle between the Romans and Greeks in which parabolic mirrors supposedly set fire to invading ships. So before we explore ray guns and other invisible-beam weapons—some of which actually now exist—we must start with the father of all such ideas, Archimedes, and his defensive tactic, conceived in 212 BCE, of burning approaching enemy ships with focused energy.
Most people know the gist of the story: Archimedes set fire to Roman ships attacking his home city of Syracuse by focusing sunlight. But to this day there’s controversy about the weapon he used. Did the brilliant Greek inventor employ a giant concave mirror? Or did he deploy a Greek battalion wielding hundreds of mirrors?
You’d think historians and researchers would have settled the matter long ago. Books have been written about the Archimedes heat ray; experiments trying to replicate it have been performed, and the US TV show MythBusters tested the problem in two separate episodes, most recently in 2011.
Unfortunately, the earliest surviving accounts of the event date from 1,400 years after the battle—a long interval indeed. Byzantine scholars Joannes Zonaras and John Tzetzes, writing in the twelfth century, paraphrased parts of a work by Cassius Dio called Roman History, published in the third century CE. The section about the siege of Syracuse said, in part:
When Marcellus [the Roman general] had placed the ships a bow shot off, the old man [Archimedes] constructed a sort of hexagonal mirror. He placed at proper distances from the mirror other smaller mirrors of the same kind, which were moved by means of their hinges and certain plates of metal. He placed it amid the rays of the sun at noon… [and] a frightful fiery kindling was excited on the ships, and it reduced them to ashes, from the distance of a bow shot.
The original source of this account survives only in fragments. So the most logical way to verify this fascinating event in our modern techno-savvy age would be to construct the kind of mirror Archimedes might have created and see if it works.
The method seems reasonable. Most of us, as children, focused sunlight using a magnifying lens and burned a hole in a piece of paper. We discovered that the color of the paper made a huge difference. White paper let the dazzling sunbeam linger a long time with no initial effect. Smoke would eventually appear, and all the while the tiny focused spot of sunlight was uncomfortably brilliant to the eye. Black paper, by contrast, catches fire fairly quickly. So right from the start we see an obstacle for Archimedes: the enemy Romans were unlikely to have obliged him by using dark sails, which would have helpfully absorbed rather than reflected the heat-producing infrared radiation from his mirror.
One can also concentrate sunlight (and, as we’ll soon see, invisible rays) using a parabolic mirror instead of a lens. Indeed, a mirror is much easier. Any hobbyist with an old telescope mirror can ignite a fire within seconds, even if the mirror is just six inches across. The distance from which the fire can be set depends on the mirror’s focal length. Telescope optics bring rays to a focus a few feet away, but if a telescope was built to achieve focus at a few hundred yards, it could easily do the job Archimedes intended.
Current technology uses mirrors to concentrate the sun as a way of generating electricity. A huge solar array of two thousand swiveling and tracking mirrors in the Mojave Desert near Barstow, California, focuses sunlight on a tower, where molten salt absorbs the heat and transfers it to a water boiler below. The resulting steam turns generators that produce ten megawatts of electricity. A giant array like that could ignite wood or sails virtually instantaneously.
One hurdle for Archimedes is that every mirror has a fixed focal length. How could he know exactly how far away the Roman ships would be? If you misjudge the distance, the light is spread out and you can’t achieve the kindling temperature for sails, which is around five hundred degrees Fahrenheit. Moreover, it would take an enormous mirror to do the job, one at least ten feet across. On top of that, the metal mirrors available to Archimedes in his day would only reflect around 65 percent of the light hitting them, compared with the 90 percent that today’s “silvered” mirrors reflect. Size for size, Archimedes would have needed three old-fashioned mirrors to do the job of two modern mirrors.
Practically speaking, it appears that success would be most probable if Archimedes had a large number of his soldiers each hold separate flat mirrors rather than try to guess the correct distance so that he could fashion a giant parabolic mirror of the required shape. If the soldiers all stood aligned in an arc, they could create a crude parabola, or they could simply stand anywhere they wanted and aim their spot at a single place on the enemy ship.
Testing this idea in 1973, a Greek scientist named Ioannis Sakkas had sixty Greek sailors each use a three-by-five-foot flat mirror to focus sunlight on a wooden rowboat 160 feet away. He reportedly succeeded in starting a fire “very quickly.”
But hold on. In 2009, a class at MIT tried to reproduce Archimedes’s feat using 127 one-by-one-foot mirrors. They did get a large piece of dry red oak (representing boat material) to start burning after ten minutes—and that was using mirrors with just one-seventh the total area of the 1973 experiment. A later MIT experiment used an actual old boat and achieved similar results. But ten minutes is a long time to stand there in the heat of battle—especially if the sailors on the boat were meanwhile tossing pails of water on the bright spot the moment it started smoldering.
MythBusters tried to settle the matter in an episode aired in 2010, with the help of volunteer middle school and high school students holding five hundred mirrors. Their results were discouraging. Despite an hour of focusing the sun on a sail, a ship’s weak link when it comes to flammability, they could only get the temperature of the beam up to around 230 degrees. That would have boiled water but not initiated combustion.
Adding to the discouragement is the fact that writers of Archimedes’s era, including the famous Plutarch, never mentioned any use of mirrors to set ships on fire, even though they amply described other innovative devices used by Archimedes. Centuries later a few writers did say that Archimedes set fire to the Roman ships, but they omitted any mention of mirrors, which should have been dramatic and unusual enough to merit inclusion in the story. Most analysts assume that Archimedes used other fire-starting measures, such as petroleum. (Ultimately his strategies failed. He was killed by a Roman soldier during the ensuing battle, even though the Romans had standing orders to sp
are his life when they found him.)
The consensus is that the story is probably apocryphal, although not impossible. Still, its fame has kept alive the idea of a weapon that focuses energy.
Fast-forward to 1898, when H. G. Wells introduced the fearsome Martian weapon used against Earth—the Heat-Ray. William Herschel’s old term calorific ray had already changed to infrared ray decades before The War of the Worlds became a bestseller. But “Heat-Ray” sounds cooler and scarier than “infrared ray.” In 1953, in John W. Campbell’s sci-fi bestseller The Black Star Passes, we find the first-ever mention of something called a ray gun. But gadgets that shoot “disruptor rays” and “annihilator beams” appeared even earlier, in stories from the 1930s, and became a standard armament in the Buck Rogers stories. (In the 1951 movie The Day the Earth Stood Still, a lethal ray disintegrates only inanimate objects, a humane characteristic seen nowhere else in fact or fiction.) The idea behind a “disintegrator beam” was that it somehow nullifies the electrical forces that bind the subatomic particles within atoms, leaving the material to fall apart as ionized fragments. In reality, to make atoms disintegrate, a weapon would also have to nullify the strong force that keeps nuclei intact—but no sci-fi author seems to have bothered with such particulars.
While writers and filmmakers dreamed up hypothetical directed-energy weapons, the technology that could enable them was close at hand. In 1957, Columbia University graduate student Gordon Gould figured out a way to make photons march in unison, a phenomenon predicted half a century earlier by Albert Einstein. He even coined a term for it: LASER—light amplification by stimulated emission of radiation. A laser could create and focus coherent streams of visible or invisible light with equal ease. At this time, Bell Labs was also furiously trying to find a way to make light waves’ peaks and troughs pulse in unison. When they built the first usable laser, in 1960, there ensued a patent fight that wasn’t resolved for seventeen years. Historians still debate the matter of who really invented the laser.