Table 18.2 The Electromagnetic Spectrum

Radiative weapons are comprised of the class of devices which achieve their deadly results by the use of projected radiation — acoustic radiation is usually excluded from this category. There are two varieties of radiative weaponry: electromagnetic (photonic) and particulate (atomic and nuclear particles). We‘ll look first at the electromagnetic ones (Table 18.2).

Static fields need be considered only briefly. There is little or no evidence that mere electrostatic or magnetostatic fields have any effect whatsoever on the human organism. No gross effects have been observed in tests of laboratory animals subjected to magnetic fields up to several kilo-gauss.⁵⁶⁸ Likewise, few significant effects are reported from exposures to time-invariant electric fields. Hence, we find that static fields won‘t be useful to aliens as weapons.

VLF (Very Low Frequency) radiation has long been considered virtually harmless. It is emitted, for example, by power lines and electrical appliances we use every day. How could VLF possibly be harmful?

There are several interesting effects produced by exposure to slowly oscillating magnetic fields, such as the magnetic phosphene.⁵⁶⁶ The French physicist d'Arsonval was the first to describe these colorless "shimmering luminosities" in the last century. Application of VLF frequencies of from 10-100 Hz to the head causes these flickering phosphenes to appear at the borders of the visual field.⁵⁶⁸ Could ETs make us think we see ghosts?

• Muscle contractions have also been induced in frog tissue by VLF radiation.
• Furthermore, a study conducted in the Soviet Union a few years ago concluded that exposures to 50-100 volts per centimeter have significant effects on humans. Subjects reported tremors in arms and legs, slowed heartbeat, fatigue and sleepiness,⁵⁷⁰ and even anemia.⁶⁷⁹
• Recent Navy research has demonstrated that an electrical field at 60 Hz can alter the concentration of fats in the human bloodstream.⁴⁶³
• And according to the late Dr. Norbert Weiner, a 10 Hz ambient electrical field causes "unpleasant sensations."⁵²⁶ The oscillating field coincides roughly with the brain’s alpha-rhythm frequency.
• A variation of this technique, using scalp electrodes, is used to put human subjects to sleep — the so-called "Russian sleep machine" or "electrosleep."

But these findings are hotly contested by Dr. Otto H. Schmitt, Chairman of the Biophysics Group at the University of Minnesota. He recently completed a two-year study to determine whether or not man can detect VLF magnetic fields. Schmitt found that not one of his 500 subjects could consistently tell when the field was on or off. "Humans are relatively immune even to strong magnetic fields," he writes, "so long as they are not shocked, burned, or grossly polarized by the fields."⁶²⁹ He points out, however, that persons with prosthetic or bionic equipment (such as a pace-maker implant for the heart) might be particularly susceptible even to relatively low intensity VLF fields.

Accordingly, we can only note that at present the data are inconclusive. If it turns out that VLF is harmful after all, it’s a fair bet the aliens will know about it too!

Of course, we have been discussing using VLF against humans directly. But aliens could build giant inductors and utilize the well-known principle of inductive heating on any metallic object, such as cars and spaceships.⁵⁴⁸ Inductors use frequencies from 10 Hz up to 1 MHz, the former allowing uniform volume heating and the latter causing mere skin heating. A one-megawatt inductor weapon should be capable of raising one ton of metal about two degrees Celsius every second.*

* Such a weapon would require only two hours to raise an Apollo command module to red heat. The craft would reach its melting point four hours after heating began, and would be reduced to a spherical molten mass about ten minutes later.

Radio wave, microwave and infrared effects are manifested primarily as simple radiative heating.

• The longer radio waves cause thermal agitation and rotation of molecules, resulting in a rise in temperature of the bulk material subjected to irradiation.
• Microwave and infrared, on the other hand, stimulate molecules in what are called vibrational modes.
• Both infrared and visible radiation act on the whole molecule, causing direct heating. But the ultimate result is essentially the same — increased temperature.
• As far as specific destructive power is concerned, suffice it to say that a narrow beam of such radiation could burn a hole through a human with only a few tens of kilojoules of energy.

Infrared and lower-energy forms of electromagnetic radiation are known collectively as nonionizing radiation.

• Such radiation doesn‘t really alter the electronic state of the molecules themselves, but merely shakes them up a bit.
• It has been shown that nonionizing radiation doesn‘t cause genetic damage.
• Fruit flies tested under kilowatt Hertzian radiation for 12 hours evidenced no mutational changes whatsoever.⁶⁸⁰

Visible and ultraviolet light are considered to be slightly more "penetrating" forms of radiation.

• These photons are absorbed by the orbital electrons of atoms, but the energy thus absorbed is sometimes insufficient to knock the electrons clear of the atom.
• The excited but unionized atom is still plenty reactive, bringing about the production of deadly photo-products such as hydrogen peroxide in surface cells.
• UV is selectively absorbed by nucleic acids and proteins, and the mutagenic effects of UV bring on skin cancer.
• Exposures to as little as 600 joules over a naked human body causes surface cells to perish, "not only due to the disruption of nucleic acid synthesis, but also due to damage to the fine structures and disturbance of metabolism."⁴⁴⁵

As we move to still higher energy radiation, we enter the realm of X-rays and gamma rays.

• The activities of such radiations are not confined merely to the surface, but are instead deeply penetrating. These are called ionizing radiations.
• Photons of large energy are absorbed by orbital electrons but, unlike visible or some UV radiation, these electrons are hurled from the atom, leaving behind a charged ion. Such ionized atoms are extremely reactive chemically.
• The biochemical effects appear only after a period of latency, usually a few days or weeks.
• Radiosensitivity is marked in cells with high metabolism and high reproductive rates.⁶⁰⁴
• Lethality doses for man run approximately one kilojoule for X-rays (1.5 × 10¹⁷ photons/m²)
• Lethal dose of three kilojoules for "soft" gamma radiation (2 × 10¹⁵ photons/m²).³⁷⁹

How can electromagnetics be applied to the science of weaponry? The earliest use was the invention of radar. It’s generally assumed that if an alien spacecraft were to approach Earth without warning, our Ballistic Missile Early Warning System (BMEWS/SAGE) could not fail to pick it up. This is a gross misconception. In addition to the fact that the SAGE computers are specifically programmed to ignore any nonballistic UFO-like targets, our radars are only effective out to a few hundred kilometers, at best. An object a few megameters away, even if in Earth-orbit, could easily evade detection indefinitely. Farther out than that, and our chances of detecting the intruder are virtually zero. As Robert Salkeld points out in War and Space, it took the better part of a month for Earth-based observatories to locate and detect laser echoes from the specially-designed Apollo 11 reflector left behind on the surface of the Moon. Salkeld laments: "The far greater difficulty of picking up a distant target whose location and even existence are uncertain, and which is designed to be non-reflective, should be obvious."⁵⁶¹ A surprise attack from space is therefore quite possible.

But certainly the most alarming photonic weapons technology is the military laser. A bewildering array of possibilities has suddenly become available. For instance, it’s well known that to gaze into a laser beam of even low intensity can cause permanent blindness. It has been suggested that "satellite blinders" could be placed in orbit by aliens. Anyone who glanced at the sky for more than a few moments would become permanently and irreparably blind. Arthur C. Clarke uses a variation of this idea in his short story "The Light of Darkness."⁶³⁷

Another unusual application is the laser listening device. Victor Marchetti and John D. Marks, in their collaboration The CIA and the Cult of Intelligence, relate that in the early 1960s the CIA developed an apparatus which fired a tiny pencil of laser light at a closed window. Vibrations of the air inside the room — due to people talking — set the window pane vibrating. This in turn caused minute fluctuations in the reflected laser beam which could be decoded and reassembled back into the original speech, at the receiver! Although the contrivance apparently had a few technical bugs, the idea of spying on a nearby alien spacecraft — in windless, airless space — is intriguing.

The Pentagon is now examining the possibility of placing a network of "defense" satellites in orbit, each armed with powerful lasers. These orbital robots would approach and destroy "alien" hardware, or disable missiles that flew within range. The Soviets are reportedly working on a satellite-killer of their own.

This brings us to the "big daddy" of laser weaponry, the so-called laser cannons. The big breakthrough in high-power laser technology occurred when it was discovered that fast-flowing reactive gases could be chemically combined rapidly, releasing huge quantities of laser energy. The Gas Dynamic Laser (GDL), one of the major contenders in the high-power sweepstakes, produces a concentrated beam of laser light when its reaction gases are combined and forced through tiny nozzles at supersonic speeds.

It’s believed that prototype laser cannons will be available in the 1978-1979 period, and that working field models may be coming into use in the early 1980's.⁴⁶¹ Already the U.S. Army has fielded an experimental laser tank, called the Mobile Test Unit (MTU). From early in 1975, the MTU has been tested at the Redstone Arsenal in Huntsville, Alabama. The driver rides in front, aiming the turret in the rear at the desired target. The Electric Discharge Laser (EDL) in the turret fires a multi-kilojoule pulse, powerful enough to burn holes in wood, metal, or human flesh. Says a researcher on the MTU development team: "It‘ll go right through you right now with no trouble."³⁹²

There is also under development, by TRW Systems in Redondo Beach, California, a semi-portable laser rifle.

• Designed to be carried and operated by three men, this high-energy chemical laser is aimed like a shotgun and fired.
• It is supposedly capable of burning a centimeter-wide hole in an unprotected human body at a range of up to eight kilometers.
• "Once you‘ve got him in your sights," says one TRW engineer, "you‘ve got him. There are no misses."³⁹⁴

• As for gross power and destructive capability, Avco has reported that its eight kilowatt continuous-operation laser cuts through Plexiglas at about 2.5 cm per second.⁵²⁷
• The twenty kilowatt laser at the Air Force Avionics Laboratory near Dayton, Ohio, is capable of burning three centimeter wide holes in firebrick at the rate of 10 cm per second.
• It’s also known that the Air Force has since constructed GDLs capable of several hundred thousand kilowatts of contiuous power, although the exact details remain classified.³⁹⁷
• Dr. J. Paul Robinson at Los Alarnos speaks matter-of-factly about orbiting megajoule lasers in the near future.⁴¹⁰
• It is a fact that the Pentagon spent nearly $200 million in Fiscal 1976 on laser weapons technology alone.

High frequency lasers haven‘t actually been constructed as yet, but it has been emphasized repeatedly that both X-ray lasers⁴⁹¹ and gamma ray lasers, called grasers,^{475, 506} are theoretically possible. Even though practical feasibility has not been demonstrated, many scientists are already predicting that when x-ray lasers are constructed, energy fluxes "greater than one kilojoule per square centimeter" will be available.⁵⁰⁷

Admittedly, laser "death rays" have their limitations.

• Since light travels in a straight line, beams cannot be aimed at anything below the horizon unless orbital mirrors are used.
• Furthermore, laser light is scattered or absorbed by clouds, mist, dust, fog, and smoke.
• If the target is shiny and reflective, most of the laser’s energy can be dissipated harmlessly.

And yet it’s still considered a very promising weapon.

• It fires high-energy "projectiles" that travel at the speed of light.
• Aiming is vastly improved.
• Were lasers to be used in space battles, where beams can travel thousands of kilometers uninterrupted to their targets, it would represent a formidable weapon indeed. Our extraterrestrial invaders will surely be aware of this.

Two other photonic weapons deserve at least a passing mention. The first of these is the idea of using focused solar radiation as an offensive weapon. This idea is really quite old. In fact, the great Greek mathematician Archimedes was the first — to the best of my knowledge — to have actually put the plan to practice. Between 215 and 212 B.C., the Roman navy beseiged the Hellenic port of Syracuse. Archimedes set fire to the fleet by using polished reflectors* to concentrate the Sun’s heat onto the attackers.

In 1969 Dr. Thomas O. Paine, a former administrator for NASA, suggested that it might be possible to place a giant solar reflecting mirror on the lunar surface. This mirror, he claimed, could be used to destroy any chosen city on Earth.⁷⁷ Arthur C. Clarke has hinted that such a weapon might be wielded from Earth-orbit. "It’s theoretically possible," he asserts, "to orbit giant mirrors in space, to hover over the Equator and to reflect sunlight to any spot on Earth. And as they need only be made of mylar film coated with a few atoms' thickness of aluminum, they would be extremely light even if they were miles on a side. It would be technically feasible to erect such mirrors using Saturn V launch vehicles …"⁸¹

The second photonic device is the practical invisibility cloak. It is often pointed out that an invisible man would also be quite blind.⁵³ I can see no easy way around this fundamental objection. However, what if aliens wished merely to render isolated structures invisible? One suggestion along these lines entails the erection of a hemispherical cap over the buildings. The outer surface of this cap would consist of a 3-D holographic "picture" of the virgin terrain prior to the construction of said building. In this case, the ETs wouldn‘t particularly care whether or not they could see out from their hideout, as they could place TV cameras outside the periphery of the cloak. Or, if it is possible to maintain a radial refractive index gradient around the buildings, a kind of spherical lens might be created. The resulting image of the refracted background should be at least as good as a fine mirage, and perhaps even better — using advanced alien technology.

And of course we can always resolve the optics problem by resorting to subjective invisibility. That is, the alien causes humans to simply ignore his presence, psychologically. For all practical purposes, the ET would have become "invisible."⁵⁵ An interesting variation on this theme may be found in Larry Niven’s science fiction novel A Gift From Earth (Matt Keller’s Plateau Eyes.²³¹

* coppered shields, about a hundred of them trained on each enemy vessel.

How does particulate radiation affect the human organism? One most unusual effect relates to visual sensations caused by the passage of fast-moving particles through the retina. It has been reported that about 10% of all relativistic nitrogen nuclei shot through a human eyeball are perceived as tiny streaks of light in the visual field.⁴⁷³ High energy muons and pions have been found to cause a similar phenomenon, appearing as a crescent-shaped flash as large as one-half the entire field of view.⁵²⁹

But by and large, the biological effects of particulate radiation are quite straightforward.

• Any particle bearing an electric charge (protons, electrons) and having a reasonably high kinetic energy will interact strongly with the orbital electrons in any physical medium it passes through.
• Charged particles lose energy to orbital electrons bit by bit as they pass, unlike photons which divest all their energy in a single blast.
• Neutral particles like the neutron cannot interact electromagnetically with matter, and zip right past the orbital electrons.
• All their energy is transferred in a single collision with an atomic nucleus — which absorbs them and recoils violently.

• We call high-energy charged particles directly ionizing radiation.
• Whereas photons of very high energy and neutrons of all energies are referred to as indirectly ionizing radiation.
• Slow moving charged particles and low-energy photons are known collectively as nonionizing radiation.

Which of the particles in the "nuclear particle zoo" are germane to our study? At last count, well over 200 different particles had been discovered. Let us briefly consider just a few of them.

• We've already mentioned the proton (positive charge) and the neutron (neutral) — the constituents of atomic nuclei — and electrons (negative charge).
• Each of these has its antiparticle. An antiparticle is the "opposite" of a particle, in the sense that when the two come together they are observed to undergo annihilation (mutual destruction) and release large quantities of energy.

• The anti-electron, the first antiparticle to be discovered, was given a special name — the positron.
• The positron-electron annihilation reaction is very specific; positrons would presumably be stable in a universe without electrons.⁶⁸¹
• The proton and neutron each have their anti counterparts.
• However, they are slightly less specific in their reactions. An antiproton will annihilate both a neutron and a proton; likewise, the antineutron annihilates both neutrons and protons.⁶⁸¹

• Pions are particles which come in three varieties — positive, neutral, and negatively charged.
• They are produced via proton-antiproton and neutron-antineutron reactions, and also in cases where protons or neutrons collide with nucleons in normal matter.
• But pions are unstable, decaying to muons and electrons in very brief times.
• Muons exist in positive and negative forms and are also unstable, decaying in about two microseconds to electrons and other particles.

Let us turn now to applications.

The most common form of electron transfer in our everyday lives is via electricity. Can this be used as a weapon? Dr. John Cover, a scientist in Newport Beach, has developed a device he calls a taser. The taser passes a jolt of electricity at 50,000 volts (but very low current) through the body, temporarily freezing the skeletal muscles with few lasting effects. This "stun gun" is being manufactured and marketed under the trade name Taser Public Defender by Advanced Chemical Technology, a Los Angeles firm.

But this device gets the energy to the human target by firing tiny darts attached to ten meter threadlike wires. Surely there must be a better way!

The alien attackers may be capable of actually throwing thunderbolts at us, those powerful instruments of Zeus' arbitrary whim.

• One of the larger artificial lightning machines was the one built for the 1939 World’s Fair in New York. Its output reportedly exceeded ten million volts at about 200 kilojoules per bolt. This is sufficient to jump more than ten meters through dry air.
• Voltages of more than twenty million volts are commercially available today.

Natural lightning is even more impressive.

• Discharges from so-called "positive giants" pass energies in excess of several billion joules, at hundreds of millions of volts electrical potential.
• The cores of such strokes momentarily reach temperatures of up to 30,000 °C, several times hotter than the solar photosphere.
• It's quite possible that hovering alien spacecraft could use a weapon of this kind to destroy houses, vehicles, or even crowds or single individuals.
• A tight beam of ionizing radiation might precede the bolt to the ground, ionizing an easy conduction path in air straight to the target.
• It would be difficult to operate a hand-held device of this kind, such as a lightning bolt rifle, as it would be virtually impossible for the attacker to avoid being shocked himself.

Of course, there are other forms of lightning. Of particular interest is the phenomenon known as ball lightning.

• After decades of controversy, it is now generally accepted that these fiery balls of electrical energy — kugelblitz — do exist.
• They are described as being anywhere from one centimeter to one meter in diameter, in colors ranging from white and blue to red and yellow.⁴⁵⁹
• The plasma globes can be spherical or elliptical in shape.⁴⁶⁶
• Lifetimes are typically about five seconds, but occasionally a kugeiblitz has been seen to remain intact for more than a minute.
• Their demise occurs in one of two ways — silently (fast or slow), or explosively with a loud pop — and they generally travel at about 4 meters per second, either vertically⁶¹¹ or horizontally.⁴⁵⁹

How much energy do they contain?

• One 20 centimeter kugeiblitz fell into a small barrel of water, causing it to boil for several minutes.⁵⁴⁹
• Another plasma ball was seen entering a heavy oak piling, which shattered violently moments later.
• The ball was estimated to contain an energy of 100 kilojoules.⁶¹⁰
• Energy densities have been variously estimated from 20 megajoules per cubic meter⁶¹¹ up to 100 megajoules per cubic meter.⁵⁰⁵
• One author has speculated that persons standing within a meter or two of a large lightning ball might well be exposed to radiation sufficient to cause radionecrosis, although the balls are rarely reported to emit heat.⁵⁰⁵

Since ball lightning requires no ionized path and appears to be self-sustaining, it should be possible for ETs to wield portable kugeiblitz projectors.

• A person directly hit with one of these plasma balls could suffer severe radiation burns, electrocution, and traumatic shock.
• There is a small problem with aiming accuracy, as the motions of the glowing balls are frequently erratic.
• However, there have been many reports of ball lightning actually "chasing" people, apparently attracted to a small accumulated net charge.⁴⁶⁶
• Aim may in fact be a nonproblem after all.

Electrons can be utilized more directly in space.

• A beam of electrons could be fired at the hull of an alien spacecraft, embedding negative charges throughout its bulk.
• The craft might then be grappled electrostatically — a tractor beam of sorts.
• Unfortunately, the forces generated are quite weak over normal operational distances, and the skin charge would be easy to neutralize by the aliens themselves.

More reasonable, perhaps, are the torch weapons. The muon torch is a prime example.

• Muons are very inert mesons, so inert that they comprise about 80% of the cosmic rays at sea level and have been detected in mines, hundreds of meters beneath solid rock.⁶⁸¹
• The depth of penetration depends almost solely upon the initial energy of the beam of particles — the higher the energy, the farther they go.
• But muons decay after 2.2 microseconds. We can arrange the beam energy so that, after the muons have traveled, say, one kilometer, the decay time has elapsed.
• One kilometer from the source, then, the particles in the beam will suddenly decay, releasing their energy with almost pinpoint accuracy.
• Range can be adjusted on the muon torch by merely adjusting the energy of the beam.

Table 18.3 Range of the Charged-Pion Torch in Vacuum

Charged pions can also provide us with a torch effect. However, since charged pions decay in only 0.03 microseconds, to get the same range pions must be accelerated to energies about ten thousand times higher than muons (Table 18.3). But the pion torch is superior for one simple reason.

• When the muon decays, most of the energy thus liberated is carried away by neutrinos and is effectively lost.
• But when the pion decays, its full rest mass energy of 139 MeV is delivered to the target.
• If the aliens have constructed a pion torch capable of delivering a pion current of one milliampere — not inconceivable using modern human technology — the weapon would have a power at the target of about 150 kilowatts.*

• The problem with charged particle torches in general is that there’s an obvious defense available.
• Electrostatic screens around an enemy ship in space would repell the pions as easily as electrons are deflected in a TV picture tube.
• Only if torch weapons aren’t expected would the torchers have a fighting chance for success.

• Neutral pions are available too, of course, and would be quite undeflectable by any electrical field.
• There would be no elegant defense against a neutral pion torch.
• There’s just one catch. The neutral pion decays in 10^-15 seconds.
• To achieve the same range as a charged pion torch, energies must be some seven orders of magnitude greater.
• Even at the terrific energy of 1000 TeV, at least three orders of magnitude above the capacity of the largest accelerator on Earth, the neutral pions would have a range in vacuum of only 2.2 meters.

* Note also that the pion decay cloud could be materialized inside the enemy ship, incinerating everything within but leaving the hull intact.

Figure 18.3 The Starship Enterprise fires its phasers

We have not yet exhausted the list of nonphotonic radiative weapons. It has long been believed by many nuclear physicists that whole atoms of antiparticles could be built up — into anti-atoms.

• An atom of antimatter would have a negatively charged nucleus surrounded by a cloud of positrons.
• Recent research has revealed the first synthesis of the anti-helium-3 nucleus,⁴⁸⁷ and the antideuteron (anti-deuterium nucleus) has been known for a decade.
• It is not inconceivable that ETs may be able to fashion macroscopic chunks of pure antimatter, stored temporarily in some kind of (perhaps) magnetic confinement vessel.

A mere 64 grams of antimatter, released on the surface of this planet, would provide an explosive yield of one megaton — the approximate energy requirement to utterly destroy a city of one million inhabitants.⁵⁷³

Other applications for antimatter may be imagined.

• A cloud of anti-plasma released at an enemy vessel in space could cause severe structural weakening of the hull, as in the original-series Star Trek adventure "Balance of Terror" and other science fiction tales.⁶⁰⁷
• Another possibility is the use of antiparticle beams to slice up chunks of ordinary matter.
• A beam of anti-protons, for instance, would cut right through a distant spacecraft.
• Not only would the ship be physically riven in two, but fierce radiation accompanying the annihilation reactions would undoubtedly prove quite deadly to the occupants.

Aliens would be smart enough not to choose antiprotons for this purpose, however, as these are susceptible to electrostatic defenses. ETs would use antineutrons instead. Or they may use other forms of beam weapons that we not yet imagined (Figure 18.3).

We regard the weather as a weapon. Anything one can use to get his way is a weapon and the weather is as good a one as any.

The science of weather modification and climate control is still in its infancy. It is therefore much more difficult to assess the possibilities than in earlier sections. "High technology" necessarily implies a more speculative effort — not to imply that weapons discussed below are any less dangerous or less real. If any of the techniques described below turn out to be unworkable for one reason or another, it’s probably unimportant. The ETs undoubtedly have far more effective ones at their disposal!

Dr. Pierre St. Amand, doing weather modification research for the U.S. Navy in the mid-1960s, said of his work: "We regard the weather as a weapon. Anything one can use to get his way is a weapon and the weather is as good a one as any."

• In 1974, the Pentagon conceded it had used weather warfare in Vietnam for more than seven years.
• In point of fact, the CIA allegedly began a rainmaking project over Saigon as early as 1963.⁴⁷¹
• This disclosure infuriated the Soviets, who promptly introduced a resolution in the United Nations calling for multilateral renouncement of all geophysical and meteorological warfare.⁴⁶²

Man has been tampering with the weather in earnest since Schaefer and Langmuir's historic snowfall-induction experiments in 1946. Unfortunately, there have been many failures and progress has been slow.

• Silver iodide and dry ice have been used to precipitate rain for decades, and recently another technique — liquid propane sprayed into supercooled fogs — has been added to the list.⁴⁶⁵
• Hail suppression research appears promising,⁴⁶⁴
• Snowfall-induction for watershed and recreational purposes has become a commercial enterprise.⁴⁷⁴
• We can disperse fogs, prevent frost, and the NOAA's Project Stormfury has had limited success in reducing the severity of tropical hurricanes.

But man’s best efforts to date still appear rather feeble.

Could aliens find ways to generate earthquakes at will?

• Small tremors have already been artificially created by pumping water into the ground under pressure. This lubricates the fault lines, allowing the crustal plates to slip.
• Another technique is to set off high explosives at a weak point along a fault, jarring it loose suddenly. If the blast site were judiciously selected by alien geophysicists, the resulting quake could be devastating.
• Finally, there is the suggestion that earthquakes might be triggered by high intensity infrasound. It is well known that microseisms occur regularly at frequencies around 0.1 Hz,⁶²⁸ and the possibility exists that sympathetic resonances of some kind could be set up.
• Such oscillations could perhaps be induced using sonic booms. Researchers have discovered that infrasonic energy can be transmitted from the air to the ground; they have detected "air-coupled seismic waves resulting from fighter planes — flying at high altitudes at Mach numbers greater than 1.2. Such waves have also been detected in the ground below the paths of jet airliners."⁶²⁸

The average house-rattling earthquake liberates a total energy equivalent to hundreds of gigatons (about 10²¹ joules).

• Hurricanes are of similar intensity.
• But these cannot simply be "triggered" as can quakes, so we‘re faced with a much larger problem in trying to generate one.
• Tornadoes, the smaller cousin of the tropical hurricane, may be slightly easier to manage. D. S. Halacy, Jr., in The Weather Changers, notes that "there is evidence that a strong air temperature inversion at about 2 kilometers altitude is likely to produce tornadoes."⁵⁴⁷

Assuming such conditions exist in rudimentary form, can a cyclonic disturbance be generated?

Perhaps. Again, the sonic boom is our instrumentality. An aircraft flying at supersonic speeds, presenting an area of several square meters of fuselage to the onrushing atmosphere, can produce pressures equivalent to "an instantaneous 180-mph hurricane" over a swath a few hundred meters wide beneath it.⁵²⁴

• It’s possible that a rapidly circling fleet of supersonic flying machines could induce cyclonic motion in the already unstable air.
• Bernard Vonnegut, a General Electric weather modification scientist, notes that a typical tornado funnel is kept going by a power consumption of roughly 200,000 megawatts.⁵⁴⁷

Could such a tornado be dispersed? That is, have we a defense if the ETs shoot tornadoes at our cities?

A decade or two ago, it was suggested that a "weather bomb" could be exploded in or near a twister, literally blowing it out. This idea has been used in science fiction stories,⁶⁸³ but, as Halacy says: "Recent studies of the power involved in a typical tornado indicate that an H-bomb would be needed."⁵⁴⁷ Perhaps the cure is worse than the illness!

What about generating huge tsunamis, popularly known as "tidal waves"? Tsunamis are generally caused by seaquakes on the ocean floor, and some of the techniques described for earthquake generation might be applicable here.

• Seismic sea waves have been sighted as high as 30 meters on many occasions.
• There are reports of a 50 meter wave following the great Krakatoa volcanic eruption in 1883.
• The Guinness Book of World Records lists a record wave at 67 meters which supposedly appeared off the coast of Valdez, southwest Alaska in 1964,³⁶⁰
• But there are reports in reputable journals of still higher crests.⁶⁸⁴

Other techniques for generating tidal waves have been suggested, such as the detonation of a one-gigaton thermonuclear device submerged a few kilometers under the ocean surface. This would produce a wave nearly 30 meters high.

But the most ingenious idea is the planetoid attack.
Meteoroids pass close to Earth all the time.

• For instance, on 30 October 1937, Hermes (a small planetoid about one kilometer in diameter) passed within 800,000 kilometers — about twice the distance to the Moon.⁵⁶³
• The Apollo planetoids pass as close as a few million kilometers on a regular basis. These objects range from a few kilometers to as large as thirty kilometers in diameter.
• It is estimated that the Earth has been struck by one of these larger meteoroids about once every few hundred million years.⁵⁹⁸
• If the aliens were able to latch onto one such chunk of rock and iron, a few well-placed H-bombs could alter its trajectory very slightly — just enough to nudge it into a collision course with Earth.

Table 18.5 Seismic Wave Heights for Planetoid Oceanic Impact* (mean impact velocity 10 km/sec)

If a planetoid one kilometer in radius were to strike our planet:

• It would gouge out a trench 80 kilometers in length and at least eight kilometers deep.
• More than four times as deep as the Grand Canyon.⁴¹⁴

But the surface of our planet is mostly water, so a sea landing is more likely.
What if the object were to strike an ocean? (Table 18.5)

• Oceanographers have calculated that such an impact in, say, the central part of the Atlantic Ocean, would initially form a transient rim crater — a monstrous wall of water — on the order of three to six kilometers high.⁵⁹⁶

What about planetary flooding? Astronomer Stephen H. Dole has estimated that a multiplication of the terrestrial water supply by a factor of four would be required for complete inundation of all the continents.²¹⁴ Where might aliens find this much water?

Not on Earth, certainly! One old idea is the atmospheric precipitator, a device capable of precipitating out all the water held in the humid. atmosphere. However, simple calculations reveal that if all the liquid in our skies were suddenly condensed, we‘d be standing ankle deep in water. It’s possible that highly localized flooding could occur, but a widespread terrestrial deluge is quite impossible using this technique.

Perhaps ETs could melt the polar icecaps.

• The two icecaps contain a total of 23 million cubic kilometers of ice.³⁶⁷
• With all this water, the absolute sea level will rise only about fifty meters, leaving most of Earth’s surface high and dry.
• Unfortunately, many of the world’s most populous cities are located near the coast. Dr. Howard A. Wilcox in Hothouse Earth has shown that 33 of the 50 largest metropolitan areas on Earth would probably be inundated.
• This would displace about 71% of the population of those 50 cities alone — some 200 million humans.⁶⁸⁸

Wilcox suggests that icecap melting may occur naturally if mankind continues to increase its worldwide energy consumption exponentially. But we are concerned here with the possibility of aliens purposefully thawing the poles. Halacy relates that the Russians have experimented with increasing the melting rate of snow.⁵⁴⁷ This is accomplished by dusting the surface with lampblack, causing the ice to absorb solar heat more rapidly and melt. Halacy estimates that to spread a film of carbon black one-tenth of a millimeter thick over the entire northern polar region would require nearly two billion tons of the stuff. A fleet of 1000 B-52H bombers would require 50,000 missions to complete the dispersal. This technique clearly leaves much to be desired.

Could nuclear devices be used to melt the icecaps? The energy equivalent required for this feat is roughly one billion megatons. If the ETs have this kind of firepower available, why should they bother melting ice with it?

As Robert Frost agonized over the decision of whether to die by fire or ice, let us now consider a weapon that could cause an ice age to occur on Earth.

• It has been suggested that clouds of particles be circulated in an interior solar orbit, or giant sheets of reflective foil interposed between Sun and Earth, thus causing our planet to cool rapidly.
• If the Sun’s rays were suddenly cut off, the atmosphere would cool to freezing, the approximate temperature of the ocean, in a matter of days.
• From then on, the temperatures would drop much more slowly, since the huge volume of the ocean would act as a giant thermal buffer.
• However, it is believed that the Ice Ages were brought about by temperature changes as small as 10 °C.
• We could be in big trouble in very short order.

Neither of the above proposals is workable, however. Thermal agitation and the solar wind would rapidly disperse the orbital gas cloud (or the foil), and a few warhead-tipped missiles strategically detonated would probably be enough to wreck the entire scheme.

The best way to artificially cool a planet is to disperse fine dust throughout its atmosphere, way up in the stratosphere above the rain clouds. This elevates the planetary albedo, causing solar radiation to be reflected back into space. The planet will begin to cool.

Using particles with diameters of 0.01-0.1 microns, an effective job could probably be done with about 20 million metric tons of the stuff. If the aliens build a linear induction catapult on the lunar surface, and each shipment from the hypothetical ET Moon colony contains about ten cubic meters of fine dust, it would take about one year to blot out our sunlight if they send off one parcel every minute!

There are two great advantages to this weapon — from the aliens‘ point of view.

• First, the cooling is probably irreversible and would precipitate an Ice Age on Earth.
• Second, there is virtually no defense against its use, as it would be impossible to scoop out dust dispersed randomly throughout our atmosphere as fast as the ETs could dump it in.⁶⁸⁵
• About the only alternative to surrender would be a direct frontal assault on the Moon colony.

There are other devious tricks the aliens could attempt with our aerosphere. As noted earlier, exposure to ultraviolet radiation can cause skin cancer, severe burns, and "snow blindness."

• The Sun puts out lots of UV, but these rays never reach the Earth’s surface.
• This is because the natural protective ozone layer generated by the atmospheric oxygen screens them out.
• Ozone is present everywhere in our air, but most of it is concentrated in the stratosphere at an altitude of about 20-30 kilometers.
• If we could collect all the ozone from a column of air stretching from the ground to the borders of space, we‘d find that each square meter has only about four grams of this precious allotrope of oxygen above it.
• Were we to completely destroy this protective chemical layer, about 64 watts per square meter of harmful ultraviolet radiation would pelt us from the sky.

Aliens may decide to try to relieve our atmosphere of its ozone. Nitrogen oxides, SST emissions, fluorocarbons and other industrial aerosols are already beginning to do a fine job of this, but the ETs undoubtedly will want to hurry matters along. How might they go about the construction of a deozonification weapon?

• Dr. Michael B. McElroy, professor of Atmospheric Sciences at the Center for Earth and Planetary Physics at Harvard University, has intimated that bromine is so effective at destroying ozone that "it could be used militarily."⁴¹⁴
• Any halogen will do, but apparently the brownish-orange liquid element, acting as a catalyst to decompose the ozone back into oxygen, does it best.
• Each halogenic atom injected into the stratosphere can theoretically catalyze as many as a thousand reactions before it becomes chemically locked in a relatively inert form.⁵²⁰
• A simple calculation demonstrates that approximately four kilograms of bromine, dispersed in the stratosphere over each square kilometer of the Earth’s surface, will result in virtually total deozonification.
• To deozonify the entire world would require about two million metric tons of liquid bromine.*
• The supply officer at Dow Chemical Corporation in Walnut Creek, California tells me that the aliens can purchase liquid bromine from him for 30¢ a gallon — provided they buy in 2300 gallon tank car lots.
• This works out to about $52 million — not counting the cost of delivery to the stratosphere — for eliminating our planet’s ozone screen.
• Studies show that anyone exposed to the downpour of ultraviolet radiation for more than a minute would receive severe second degree burns, and would be blinded in seconds should he cast his eyes skyward.⁴¹⁷
• Terrestrial flora would begin to perish within hours.⁴⁴⁵

There are several other highly speculative "high technology" weapons. These weapons are wholly infeasible using existing human technology — but of course this doesn‘t restrict the aliens, who are all the more delighted at our lack of efficacious defenses.

Dr. Horace Dudley suggests that it may be possible to induce a runaway chain reaction in our atmosphere. He says that if a large enough nuclear device were detonated in open air, a worldwide conflagration might result.⁴⁵⁷ Although many would scoff at this idea, apparently Compton himself once performed a calculation to estimate the likelihood of such an event. The result? A small, but non-zero, probability.

We may someday find ourselves attacked by a giant "doomsday machine." Such a possibility was explored in a Star Trek adventure of the same name. A giant robot "planet-killer" was roaming the galaxy, chopping whole planets into rubble with antiparticle beams and stoking its nuclear fires with light elements extracted from the debris. Our only defenses would be ingenuity and luck.

Black holes, if you believe they exist, could even be used against us. Quantum black holes may exist, holes with relatively small masses and unimaginable densities. Theoretical physicists such as Dr. Stephen W. Hawking of Cal Tech (currently Cambridge University) have calculated that quantum holes with masses greater than about a billion tons will not have evaporated yet. If such a hole was to become trapped by a planet, it would slowly "digest" the body, eventually

resulting in a slightly larger quantum hole — and no planet.⁶⁸⁶

But if not the planet, then perhaps its sun. Niven and Pournelle have suggested, in the fictional The Mote in God’s Eye, that if asteroids are shot into a star, their sudden vaporization may cause severe instabilities leading to an explosion of the sun itself.⁶⁶⁸ But the "classic" technique, which is discussed at greater length in the following chapter, is Shklovskii’s ten billion megawatt graser.³ Supposedly, it could induce a powerful Type II supernova in any metal rich star greater than about five solar masses. Hence, using this scheme, Sol could not be detonated. However, there are at least 200 supernovable stars within 100 light years of Earth, the distance of minimum biological effect for supernovae.^{468, 469, 498} As technologist Adrian Berry remarks of this weapon: "Blowing up the sun … would be a perfect Götterdammerung for a besieged warlord. It would be a spectacle to surpass all others; but the fact that nobody would survive to witness the effects might, paradoxically, make the action even more attractive to warped or highly 'poetic' minds."⁷⁷

Still worse, the aliens could commit galacticide. Near the Galactic Core, stars are much more densely packed than out here near the rim. In more than one science fiction tale, a supernova occurring in the Core initiates a chain reaction of stellar explosions, spreading outward in a spherical wave at the speed of light. The entire Galaxy is doomed!^{687, 607}

* Between 1961 and 1971, the U.S. military dropped nearly 50,000 metric tons of herbicides on the forests of Vietnam. This represents about 2% of the mass of bromine the ETs would have to use to deozonify the Earth.