Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979;

(c) 1979 Robert A. Freitas Jr. All Rights Reserved.




Chapter 18.  Alien Weapons

"Space was full of darting, flashing, madly warring ships. The three Black superdreadnaughts leaped forward as one. Their massed batteries of beams, precisely synchronized and aimed, lashed out as one at the nearest Patrol super heavy, the Boise. Under the vicious power of that beautifully-timed thrust that warship's first, second, and third screens, her very wall-shield, flared through the spectrum and into the black."
          -- from E. E. "Doc" Smith, First Lensman406

"Jason, for the first time I regret never having studied weapons."
"You're a puppeteer. Why should you..."
"No sentient mind should turn away from knowledge. Especially no puppeteer. We are not known for our refusal to look at unpleasant truths."
          -- from Larry Niven, "The Soft Weapon"607

"There is as much art to destruction as construction!"
          -- Morely Safer, 60 Minutes221

"I am the spirit that always denies! A good thing, too, for all that exists deserves to be destroyed. It would be much better if nothing were ever created."
          -- Mephistopheles, in Goethe’s Faust (1808)


War and weapon-making have been an integral part of the millenia of human history on this planet. And yet, it is generally conceded that most of us have strong innate inhibitions against taking the lives of our fellow men. How can these conflicting tendencies be reconciled? If man hates to kill, why does he?

Dr. Irenaus Eibl-Eibesfeldt, an Austrian-born ethologist at the Max Planck Institute at Munich, has suggested that it is the improved technology of weapons themselves that have made it possible for men to ignore their natural revulsion toward murder. A weapon, he points out, makes it possible to take life easily and quickly; the weaponeer is spared the psychological contradictions of his acts by seeing his target as a mere object.

In close combat, using primitive weaponry such as spears and knives, the participants are acutely aware of the corporality of their opponents. But weapons technology -- mass destruction and death-at-a-distance -- has made it possible for combatants to lose that bare thread of empathy that energizes their inhibitions. Weapons technology makes dealing in death an increasingly impersonal affair. As Dr. Eibl-Eibesfeldt observes: "If one asked a bomber pilot to kill his victims one by one, he would be out raged at the suggestion."452

In view of the above, can we be absolutely certain that technologically superior aliens may not also wield superior weapons? As science fiction authors are fond of pointing out, advanced ETs may have many motivations -- conquest among them. It is not enough to say that superior technology necessarily breeds benevolence, since superior technology here on Earth has often made it easier for humans to kill. But even if it turns out that most alien civilizations are benevolent, is it correct thinking to ignore the quite disturbing possibility that there may be a few warlike intelligences loose in the universe?

The worth of a study of alien weapons may be questioned on other grounds. For instance, it may be asked how we can hope to comprehend weapons which are by definition far superior to our own, technologically. But this sort of question ignores entirely the cornerstone of our entire analysis of xenology -- the Hypothesis of Mediocrity. There may indeed exist forces and powers wholly beyond present science. If so, we can say nothing about them. All we can do is make the assumption that our science has a grasp of certain basics and proceed accordingly.

We must work with what we have. Turning our backs on the possibility of malevolent aliens will not make the problem go away. In dealing with extraterrestrial intelligences, we must be prepared for both the best and the worst.

There are many kinds of weapons that aliens might employ against us. Lasers, "nukes," biological agents, energy absorber fields and disintegrators are the stock in trade of science fictioneers. Authors have suggested psychological warfare, by which the nations of Earth are induced to fight among themselves. In Isaac Asimov’s story "The Weapon Too Dreadful to Use," the aliens in question perfect a means of severing the link between senses and brain, thus placing victims in a state of permanent sensory deprivation.674 Larry Niven’s "The Soft Weapon" illustrates what might happen if we were to discover an intelligent alien weapon.607 But most weapons fall into one of several categories, as discussed below. Surprisingly, there are fairly adequate defenses for many of them. However, for reasons that will become clear in the last section, there appears to be at least one weapon for which there is no defense!



18.1  Chemical, Biochemical, and Biological Weaponry

Explosives are perhaps the most common purely chemical weapon used in modern warfare. Destruction is achieved simply by gross mechanical vibration and demolition. We are probably close to the upper limits of chemical explosives technology, and it is inconceivable that aliens could do much better.

Biochemical weapons seem more subtle, and therefore more insidious, to most of us. For instance, mice have been rendered sterile by the addition of about 30% "heavy" water to their normal drinking water.47 (There are no data for humans as yet.) Or, it has been suggested that if certain items of knowledge can be transferred chemically (as suggested by recent experiments with RNA in rat brains), specific chemicals could be introduced into our environment which would cause fear or passiveness, "suppress intelligence," or "trigger a desired response on a given signal."573 But the most common biochemical weapons fall into two general categories: chemical agents, and biological agents.

Poisons are typical chemical agents. Plutonium, for example, is suspected to be highly toxic -- as little as 0.3 milligrams assimilated into the body would prove fatal.676 However, lethal doses can only be absorbed effectively by inhaling plutonium dust into the lungs, inducing death by cancer. There is relatively little danger of death by ingesting plutonium or its soluble compounds, since the actinides and their chemical brethren aren‘t utilized in human biochemistry in even trace amounts. Because of this, and other material-handling problems, the aliens would have to disperse fifteen grams of plutonium dust over a city for each cancer death they wished to cause, or about ten metric tons for a city of one million inhabitants.676 This is about one cubic meter of the stuff.

Nerve gases are equally dangerous. For instance, VX nerve gas is lethal at about one milligram per person if inhaled;360 when applied to the skin, about five milligrams.398 Hallucinogenic drugs are in the same league, although slightly less toxic. Scanty data available on this subject indicate that the lethal LSD dose may be in the vicinity of ten milligrams or less. Other drugs are less effective. It seems unlikely that ETs would choose this sort of weapon for a mass attack, and although it could be a potent means against individuals, we shall soon see that far more cost-effective weapons are available.

The most lethal of the chemical agents are the toxins. Botulin toxin is often mentioned as one of the most powerful natural poisons known. It is formed by the bacterium Clostridium botulinum, and the lethal dose for humans is about 0.5 micrograms.677 This particular toxin produces about 60-70% fatalities, and is extremely resistant to medical treatment. According to a recent United Nations study of the possible effects of biological warfare: "Botulism is...characterized by general weakness, headache, dizziness, double vision, dilation of the pupils, paralysis of the muscles concerned in swallowing, and difficulty of speech....Symptoms usually appear within twelve to seventy-two hours."678 Other toxins are somewhat less dangerous. Batrachotoxin, derived from the skin secretions of the kokoi arrow-poison frog Phyllobates latinasus of the Choco in western Colombia, has a lethality dose of about 10 micrograms per person.

How do these chemical means compare? Dr. Matthew S. Meselson has estimated that to ensure effectiveness, 100 kilograms of VX per square kilometer must be used, versus 300 kilograms of botulin toxin over the same area.398 Theoretically, it would take 50 million metric tons of VX to cover the entire surface of the Earth, or about 150 million tons of botulin toxin. This is the best that mere chemical agents can do, and it seems unlikely that aliens would care to synthesize such huge masses of relatively ineffective substances.

We turn, therefore, to the biological agents. As pointed out in the United Nations study, lethal chemical agents are doled out in milligram quantities; for the more powerful toxins, microgram doses are required. But bacterial agents are so effective that lethal dosages are measured in picograms (trillionth’s of grams).678

One of the most vigorous infectious agents is plague. Reasonably effective treatment exists for bubonic plague, but not for pneumonic plague. Studies of the disease in primates indicate that exposure to as few as 100 bacteria cause death in about 50% of the animals. Ten picograms could constitute a lethal dose for man. To quote again from the U.N. report: "A large mass of plague bacteria could be grown and probably lyophilized (freeze-dried) and kept in storage. The agent is highly infectious by the aerosol route, and most populations are completely susceptible. An effective vaccine against this type of disease is not known. Infection might also be transmitted to urban and/or field rodents, and natural foci of plague may be created."678

A favorite among science fiction writers a decade or two ago was the "anthrax bomb." Anthrax (Bacillus anthracis) is normally found as a disease in domesticated animals such as sheep, cattle and horses, but most animals are susceptible. It is commonly transmitted to man through the skin, or by ingestion or inhalation of the spores. The inhalation infectious dose for man is estimated variously as from 20,000 -- 50,000 spores. Early symptoms occur about one day after exposure, and resemble those of a common cold. Unless there is early treatment with antibiotics immediately, however, death ensues two or three days later in virtually all cases.

How do biological weapons compare to chemical agents? Using the most infectious bacteriological agents, it is estimated that 100 grams per square kilometer would be sufficient to "disable" a totally unprotected population of humans.573 To infect every person on Earth should require only 50,000 metric tons of, say, pneumonic plague bacteria. This could be accomplished with a fleet of two hundred B-52H Air Force bombers in only ten missions. Such is doubtless the method of choice for malevolent aliens, who could synthesize still more virulent strains of microorganisms with virtually universal resistance to medical treatment.

There are other "genetic" weapons. Prosserman suggests the following: "A water additive that slowly alters the proportion of male-to-female births in the enemy population, or that amplifies sex-drive, or counteracts population control measures. 'Cloning' could be serially produce a race of 'super-soldiers' from a single individual."573

More frightening, perhaps, is the possibility of genetically tampering with animals or rodents,2012 rendering them more prolific and more vicious. But why stop with mammals?2015 According to Stanley Baron in The Desert Locust, a typical swarm of these 6 centimeter-long insects can contain up to ten billion individuals, massing 100,000 tons in a cloud covering some 500 square kilometers. What if the aliens managed to create a new breed of insect, extremely vicious and aggressive? Impossible?

Maybe not. In 1957, genetics professor Warwick E. Kerr of the School of Medicine of Ribeirao Preto in Sao Paulo, was performing experiments in crossbreeding with African bees. By accident,26 African queens escaped into the Brazilian jungle, carrying their inimical genes with them. In less than a year, a new race of highly aggressive bees arose through in breeding with the common European varieties. Horror stories of these bees attacking humans are legion. In one case, a schoolteacher slapped at her arm when one of the "killer bees" stung her. The insect released an alarm odor. Suddenly, thousands of angry bees engulfed the unfortunate female, and swarmed around anyone who tried to assist her. She died a few hours later.670

It must be pointed out that bees generally do not attack except in self-defense or to protect the hive. But "killer bees" are apparently extremely "nervous." Could not aliens breed an even more aggressive insect?



18.2  Bionic Weaponry

In an earlier chapter we discussed various principles of bionics. We examined some of the designs for mechanical bodies which might be utilized by intelligent biological entities. There is no need to cover this ground again here, except to briefly review the possibilities of bionics as weaponry.

Certainly the most widely discussed application of bionic technology is in the field of ESB research. ESB -- Electronic Stimulation of the Brain -- normally refers to the implantation of electrodes deep within a living brain. These electrodes are pulsed with minute quantities of electrical current in the milliamp range. This interferes with the normal processing of signals by the brain, resulting in altered behavioral patterns.

In animals other than man, a considerable amount of behavioral control has been achieved. Rats and cats are driven to engorge themselves with food under electrical stimulation, and starving cats have been induced to refrain from eating even though dishes piled high with food were placed before them.495 The diameter of the cats‘ pupils can, with suitable electrode implants, be controlled "as if they were the diaphragms of cameras."92 A small cat, upon receiving proper stimulation in the tectal area of its brain, willingly attacks a much larger animal. Moreover, it will continue to fight even when clearly outmatched by its adversary.92 Female monkeys have been induced to completely lose interest in their young,513 and highly aggressive rhesus "bosses" have been rendered docile under ESB.92 And Dr. Jose M.R. Delgado, one of the leading researchers in the field, dramatically demonstrated the power of ESB more than a decade ago by stopping a charging bull dead in its tracks at the touch of a button. The bull had been "wired" for remote control.484

We find that in animals, ESB techniques have been able to control, or at least alter, behaviors of eating, sleeping, aggression, play and sexual activity. But there are also reports of control over motor activity as well. Dr. Lawrence R. Pinneo and his team at the Stanford Research Institute in Menlo Park implanted some thirteen electrodes in the brain stem at the back of a monkey’s head. Small portions of the animal’s motor cortex had been surgically disconnected for the experiment. Pinnec’s device, the Programmed Brain Stimulator, fired the electrodes in the proper sequences to evoke motor responses from the monkey. One programmed sequence, for example, permitted the animal to reach out with its paralyzed arm, grab a piece of food, and return this to its mouth. Another sequence enabled the monkey to reach around and scratch its back, a complicated series of arm and wrist motions. The motor cortex was mapped in more than 200 locations. The experimenters learned exactly which parts of the brain controlled wrist flexion, knee and hip twisting, and grasping movements.516 It would appear that full motor control is possible, at least in theory.

Applied to humans, ESB has been able to evoke pain and pleasure, fear, friendliness, and "cooperative attitudes in previously recalcitrant patients."513 Are there any limits to this research? Delgado, now chairman of the Medical School at the University of Madrid, sees fears of mass control of humans as "fantasies". "ESB may evoke well-organized behavior," he explains, "but it cannot change personal identity."484 He cites two examples to support this position.*

First, in all experiments performed to date, researchers have been unable to use ESB to stimulate a male monkey to attack its mate. That is, certain strong inhibitions seem very difficult to overcome. Second, when ESB is used to induce cats to fight one another, it is not a blind, wanton aggression. The attacker carefully sizes up its opponent, selects the best moment at which to strike, and so forth -- as in a real fight. It would appear that ESB can alter certain emotional states. What ESB seemingly can not do is alter the subject’s will, except insofar as will is ruled by emotion.

Whether or not alien technologies will find this a fundamental limitation is anyone’s guess. If their ESB technology is vastly superior to ours, they may be capable of surgically implanting electronic stimoceivers in human subjects. We already know that many primate motor functions can probably be remote-controlled, at least in theory, and certain emotional states as well. It remains to be seen whether ESB techniques can be extended to mental volitional states as well.

ESB is not the only bionic technology that could be employed by ETs. The state-of-the-art of robot building and prosthetic aids has already been examined. Here I wish only to call attention to the possibility of advanced machine warfare. For instance, the Russians have made no secret of the fact that they are researching the possibility of using disembodied cat brains as control units in air-to-air missiles. The possibility of keeping brains alive outside their bodies has been confirmed by Dr. Robert J. White of Case Western Reserve University in Cleveland. Dr. White has succeeded in keeping several monkey brains alive in total isolation.92

But brains need not be disembodied to utilize machine technology. Possibilities include such devices as Hardiman (an artificial exoskeleton worn like a suit of armor), the CAM (Cybernetic Anthropomorphous Machine) electronic horse, the huge biped CAM pedipulator, and the proposed fifteen meter high maxipulator -- also a biped. These colossal mechanical "teleoperators" hydraulically multiply the user’s strength and stride by an order of magnitude or more. One is reminded of the giant machines used by the attacking Martians in H.G. Wells’ science fiction classic The War of the Worlds.

The invaders may not wish to risk their own bodies in warfare, even behind the relative safety of a Brobdingnagian automaton.2017 Dr. M.W. Thring, head of the Mechanical Engineering Department of Queen Mary College, University of London, believes that the military robot may soon be a practical enterprise even with limited human technology. In two decades, he claims, we may be able to mass produce robot infantrymen for as little as $10,000 apiece -- comparable to the cost of training and equipping a human soldier in a modern army. Such automata would easily out perform their biological counterparts, having greater durability, flexible energy requirements, and no lack of élan for suicide missions.92

There is a fair probability that if we are attacked by hostile ETs, it will be a battle fought exclusively by specialized war machines.2016


* Unnecessary if we implant direct neural taps to sensory and motor lines.



18.3  Sonic Weapons

Sound, or acoustic radiation, might well be utilized by extraterrestrials against man and his artifacts. Although clearly limited in usefulness by the need for a transmitting medium (Figure 18.1), there are many jobs for which sonic weapons are uniquely suited.

The frequency spectrum for sound is chauvinistically, but conveniently, divided into three general regions -- the infrasonic, the sonic, and the ultrasonic. Infrasonic radiation ranges from about 0.001 Hz (cycles per second) for some seismic disturbances up to about 20 Hz. The sonic range, the bounds of human hearing, extends from 20 Hz on up to roughly 20 KHz. Then the ultrasonic takes over, reaching from 20 KHz up to 1 MHz (one million cycles per second) and beyond.


Figure 18.1 Range of Sound in Air and Water



A few general aspects of bioacoustics must first be appreciated. Figure 18.2 shows the two most important curves to our analysis. The first of these is called the threshold of hearing. This is the contour of zero loudness for normal human ears. It is the absolute lower limit of quietness below which we hear nothing.* Note that in the lower sonic range (20-200 Hz) and in the upper sonic range (above 10 KHz), sounds must be considerably more intense for them to become audible than in the middle regions of the spectrum.

The second important curve is called the threshold of pain. Sonic radiation of an intensity greater than this value at any frequency can cause permanent hearing impairment and excruciating physical pain, often described as an uncomfortable tickling sensation in the ears. Certainly, then, aliens could use focused sonic beams to quickly deafen their victims with an agonizingly painful blast of audible sound.


Figure 18.2 Sonic Intensity and the Thresholds of Hearing and Pain


But to leave it at this is to miss the most frightening aspect of sonic weapons. Compare the two threshold curves. The pain curve lies below the audibility curve for both infrasonic and ultrasonic frequencies. Beams of acoustic radiation of these kinds could be virtually undetectable by our ears, and yet carry an intensity well above our pain threshold. Here we have an "invisible" weapon, a force which can severely affect us physiologically -- yet we are unable to hear it. The specific effects of various frequencies differ, and we take this up next.

Although research in infrasonics is surprisingly scanty, one important conclusion has definitely emerged: Subsonics can affect humans adversely. Infrasound is felt rather than heard, and has the potential of shaking bodies and buildings to pieces at high intensities. But what are the usual symptoms of human exposure?2152

At relatively low power levels (about 120 dB) subjects report chest vibration, throat pressure and interference with respiration, and visual field vibration.431 Whole body mechanical vibration is very common.628 There are reports that emotional states may suffer some alteration under the influence of low intensity waves. It is entirely possible that fear may be induced,537 or psychological depression.432

At higher intensities, the effects are far more pronounced. Vladimir Gavreau, head of the Electroacoustics Laboratories of CNRS in Marseilles, France, relates that five minutes, exposure to 200 Hz at 160 dB caused painful and intense frictional rubbing of his internal organs, resonating with the sound. The accidental exposure was described as "almost lethal" by one researcher,448 and apparently the resulting pain took days to fully abate. Had they remained in the sonic fluence for another few minutes, there would almost certainly have been severe internal hemorrhaging, followed by death.

An Air Force study in the early 1960's tested subjects at power levels of 150 dB using frequencies of 50-100 Hz. The following symptoms were reported: coughing, choking respiration, pain on swallowing, headaches, loss of visual acuity and giddiness, severe substernal pressure, gagging, and tingling sensations.431

Lower frequencies seem to be most energy-efficient in eliciting disabling symptoms from the human organism (Table 18.1). Research in the subsonic range 2-20 Hz indicates the following: Intensities as low as 120 dB cause dizziness, feelings of lethargy and general lack of control.448 At 150 dB there is intense discomfort related to the organs of balance, causing nausea, a sensation of rotating, and involuntary movement of the eyeballs.622 General disequilibrium, disorientation, lassitude and weakness, and blurring of vision are also common.628 It would seem that high-intensity "subsonic stunners" postulated in various science fiction tales are a practical possibility.231


Table 18.1 Effects of Mechanical Vibration on Man628

Specific Vibrational Effect on Humans

Sound Frequency Range

Estimated Human
Tolerance Levels

Major body resonances

3 Hz – 300 Hz

140 -- 150 dB

Effects on postural control

0.1 Hz – 10 KHz

140 -- 155 dB

Motion sickness

0.1 Hz – 1 Hz

140 -- 145 dB

Blurring of vision

3 Hz – 1 KHz

140 -- 155 dB

Disturbance of breathing, speech

1 Hz – 100 Hz

140 -- 150 dB

Interference with task performance

3 Hz – 1 KHz

140 -- 155 dB


Infrasonic and low sonic radiation can also cause massive structural damage. The resonant modes of vibration for bridges, buildings and cars range from 10-100 Hz. Destruction occurs when a standing wave arises along one vibrational mode of the structure. At this resonant frequency the waves are virtually undamped and can build rapidly to a critical level -- as in the famous case of the Tacoma Narrows Bridge at Puget Sound, Washington, in 1940.

Infrasonic radiation surrounds us all the time. "Quiet" automobiles traveling at the speed limit commonly put out more than 100 dB in this range. Infrasound cannot be stopped by any normal building material, walls, or acoustic absorbers, since its wavelength is too long.

Gavreau has already constructed several alarmingly powerful "sonic guns." One such device is capable of emitting two kilowatts of power at 37 Hz. It has never been run at full power, since even at low levels the ceiling begins to crack and major body resonances are set up. Gavreau is reportedly now at work on the problem of building highly directional sonic projectors; for instance, an organ-pipe device 24 meters in length designed to operate at 3.5 Hz.628 He has estimated that large sonic cannon more than seven meters in diameter could now be constructed with power outputs close to the theoretical maximum for air -- roughly 200 dB.448 Can the aliens be far behind?

But let’s not ignore the opposite end of the sonic spectrum. Medical studies have shown that although ultrasonic radiation has more effect on the white matter in the brain than on the grey matter (the cerebral cortex), most neural components can be destroyed in a given region "without interrupting the blood vessels in the same region."623 Only a very detailed autopsy could reveal the true cause of death.

Other than effects on hearing acuity, however, the primary biological consequence of ultrasonic irradiation is vibrational heating. It is well-known that heat resulting from 20 KHz at 150-160 dB is quite sufficient to kill small animals. But apparently the presence of fur serves to absorb this radiation, and shaven animals fare much better. Men exposed to 150 dB were not significantly affected in one study,627 but it has been reliably estimated that 180 dB of airborne ultrasound would constitute a lethal dose for humans.

Would ETs select an ultrasonic weapon? It’s doubtful. Present human technology has been able to produce focused ultrasonic radiation, using a curved radiator, of more than 190 dB. That is, we‘ve already nearly attained the theoretical upper limit, and the effects are well known to us. And as we shall see in the next section, there are much more efficient ways to cause thermal destruction, techniques not nearly so range-restricted and medium-restricted as ultrasound.


* Intensity is measured in dB (decibels), a logarithmic scale of power pressure impinging on the ear. 30 dB is considered very quiet. Normal conversation takes place at about 60 dB. Driving diesel trucks or motorcycles exposes one to about 85-90 dB, and rock concerts may reach 110 dB or higher.



18.4  Photonic Radiative Weaponry

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).


Table 18.2 The Electromagnetic Spectrum

Spectral Region

Frequency Range

Wavelength Range

Static fields




n < 103


n > 3 x 105


Radio (Hertzian)

103 – 109


3 x 105 – 0.3



109 – 1012


0.3 – 3 x 10-4



1012 – 4 x 1014


3 x 10-4 – 8 x 10-7



4 x 1014 – 1015


8 x 10-7 – 3 x 10-7



1015 – 3 x 1016


3 x 10-7 – 10-8



3 x 1016 – 1019


10-8 – 3 x 10-11


Gamma rays



n < 3 x 10-11



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.*

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 x 1017 photons/m2) and three kilojoules for "soft" gamma radiation (2 x 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 1960's 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 wind-less, 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 (Mm). 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 And 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


* 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.

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



18.5  Particulate Radiative Weaponry

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 with out 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. Its 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.

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.*


Table 18.3 Range of the Charged-Pion Torch in Vacuum

Pion Energy


Pion Energy


   1 MeV

1 meter

 10 GeV

550 meters

  10 MeV

 3 meters

100 GeV

5.4 Kilometers

100 MeV

10 meters

  1 TeV

54 Kilometers

   1 GeV

60 meters

10 TeV

540 Kilometers


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.

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


Figure 18.3 The Starship Enterprise fires its phasers.


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).


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



18.6  Nuclear Explosives

Nuclear explosives don‘t fit neatly into the above categories, for the simple reason that the blast products consist of virtually every brand of destructiveness discussed so far. About half of the energy of a thermonuclear device comes off as sonic energy, in the form of high pressure shock waves and gross mechanical vibration. The other half consists of electromagnetic radiation of all kinds, primarily x-rays but including ultraviolet, visible and radio emissions. Nuclear radiation, primarily fast neutrons, constitute a few percent of the total. Fallout comprises various amounts of poisonous radiochemicals. Nuclear weapons are very messy affairs.

Many fires are started at once by the flash of an H-bomb. The majority of casualties result, not from the effects of the blast itself, but by the firestorm sweeping the victim city. Only at the very outermost edges of the hellish thermal maelstrom are individuals able to drag themselves to safety (Table 18.4).

Out in space where there is no atmosphere to absorb and scatter radiation, the destructive range is vastly increased. It has been estimated that a 20 megaton thermonuclear device would be sufficient to kill astronauts in unshielded spacecraft within a sphere nearly 1000 kilometers in diameter. A lethal sphere the size of the Earth itself would require a 10,000 megaton bomb, "a weapon which probably could be built with today’s technology."561


Table 18.4 Thermonuclear Explosive Blast Effects



Thermal Ignition and
Second Degree Burns

Severe Structural
Blast Damage

50% Blast

1 kiloton

0.8 km

0.8 km

1.0 km

0.5 km

10 kilotons

1.3 km

2.3 km

2.3 km

1.3 km

100 kilotons

1.8 km

4.0 km

4.5 km

3.1 km

1 megaton

2.4 km

16 km

10 km

7.7 km

10 megatons

3.7 km

37 km

22 km

19 km

*yield is commonly measured in tons of high explosive (e.g. TNT)


Various aerospace magazines have given rough estimates of the state-of-the-art of H-bomb building technology -- roughly 45 kilograms of bomb weight for each megaton of destructive power.563 According to Theodore Taylor in The Curve of Binding Energy, a well-designed A-bomb could be built as small as a grapefruit. Thermonuclear devices could be disguised as color television sets! Cost? Ten kiloton bombs can reportedly be purchased (authorized customers only!) for $350,000, but two-megaton devices can be picked up for a paltry $600,000.573 Bombs are cheap.

The aliens may be cleverer than we imagine, however. They may choose to attack our nuclear power plants or our nuclear weapon depositories, and get us with our own stuff! Or they may turn to the N-bomb.

The neutron bomb is a clean, low-power H-bomb. Now, A-bombs use the principle of nuclear fission -- a mass of U-235 or plutonium undergoes a chain reaction explosion. In the H-bomb, fissile components are used to achieve the high temperatures necessary for the initiation of fusion reactions between deuterium and tritium. Explosive yields are further increased by wrapping the H-bomb in a jacket of U-238, which is highly fissionable only in the presence of high neutron fluxes.

On the other hand, the neutron bomb would be a pure fusion bomb, employing no dirty fission detonator. The N-bomb would release large numbers of 17 MeV neutrons over limited areas -- perhaps a few kilometers in diameter. These neutrons have high penetrating power, and produce secondary radiation by colliding with atomic nuclei. These secondary particles are responsible for the lethality of the neutrons. There would be no ordinary fallout, although the invading aliens might have to wait a short while before entering our cities. Buildings and land would be left virtually unscathed, although the passage of neutrons would make walls and metal slightly radioactive for a few days. The fusion of as little as one milligram of deuterium could produce enough neutrons to kill 100,000 humans even through one meter of solid concrete.

But an N-bomb is more than just a pure fusion bomb. Normal thermonuclear devices have such large blast effects that the neutron damage would be lost in the greater general destruction. The range of the neutrons depends on their energy, and this is relatively constant. Hence, the trick is to build a very low yield fusion bomb, in the kiloton range. If the N-bomb was of proper size, and was exploded at just the right height, it would spray the area with deadly neutrons without causing widespread firestorms and structural damage. The N-bomb would be an excellent tactical weapon for aliens who wanted us out of the way but wished to examine our undamaged artifacts at their leisure.

Of course, H-bombs can always be made as large as desired. Gigaton yield devices (1000 megatons) have been seriously discussed, and are usually referred to as "doomsday bombs." Robert Salkeld suggests that a gigaton bomb burst in our upper atmosphere would ignite all combustible substances (forests, buildings, humans) in a 600 kilometer circle below.561 Figures released by the Atomic Energy Commission in the early 1960's show that a one gigaton warhead detonated about 16 kilometers up could be expected to start fires over an area of more than 700,000 square kilometers.525

Others have estimated that 20-gigaton devices could be "salted" to make them dirtier. A bomb wrapped in sodium would release intense, quick-killing radioactive fallout with a half-life of only fifteen hours (24Na). If the wrapping were cobalt instead, the fallout (60Co, half-life 5.3 years) would kill very slowly, but would last a long time. Or both could be incorporated in a single weapon. As one writer dryly pointed out: "The sodium-24 would knock out those who didn‘t get into deep shelters, and the cobalt-60 would immobilize those who did."525

But the true doomsday bomb is the one which, if used, could destroy all human life on Earth. Physicist W.H. Clark, a nuclear weapons technologist, has estimated that at least 1000 gigatons of nuclear explosives would be required to wipe out the human race. Freeman J. Dyson, at Princeton, comes up with more conservative figures: 3000 gigatons to kill half the human race.525

The strongest, and certainly the most obvious, argument against doomsday bombs from a military standpoint is that the attacker is destroyed along with the attacked. But would this argument be persuasive for marauding off-world aliens intent on planetary destruction?



18.7  Climate Modification and High Technology Weapons

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 "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-1960's, 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."547 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 and 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-air liners."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, and 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.

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


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

Seismic Wave Heights 

Diameter of Planetoid

Energy Released on Impact**

5 meters

100 meters

23 megatons

10 meters

200 meters

190 megatons

40 meters

500 meters

3 gigatons

100 meters

1 kilometer

23 gigatons

250 meters

2 kilometers

190 gigatons

*Adapted from tables and equations,504 assuming planetoid density r ~ 5 gm/cm3
**One megaton = 5.76 x 1015 joules


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 in creasing 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. How ever, 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.



18.8  The Ultimate Weapon

In 1952, the late John W. Campbell, Jr., wrote an editorial in Astounding Science Fiction entitled "The Ultimate Weapon."193 The discussion below draws heavily from his work, as his analysis has retained its luster even after twenty-five long years of human progress on this planet.

What, it might be asked, would be the characteristics of the Ultimate Weapon -- an irresistible force for which no defense exists? Campbell isolated the requirements that specify this device:

1. It must absolutely wipe out all opposition.

2. It should be of such nature that no resistance to it is possible.

3. It must be such that the opposition cannot turn it against the original wielder.

4. It must annihilate all opposition, yet must not harm friends.

5. It should not damage any useful or constructive forces.

6. It should be of a catalytic nature, self-propagating, such that, once loosed, even the destruction of the original source cannot defeat it.

7. It will render all present weapons inoperative.

8. Its power should be such that no power in the Universe can stand against it.

9. Its effect should not depend on surprise, so that even pre-erected defenses cannot defeat it.

10. It should cost very little to use.

11. The field where it has once been used should be permanently uninhabitable by the opposition, but freely accessible to friends.

What weapon imaginable could accomplish so much, so perfectly? As Campbell notes, the Ultimate Weapon must wipe out all opposition, but this does not necessarily imply that men must die. And since any physical weapon can be countered by physical forces, the Ultimate Weapon must be nonphysical. The wielder must desire to wipe out opposition, not fellow sentients.

Opposition may be wiped out by inducing friendship. Friendship cannot harm friends or be turned against the original wielder. It is inexpensive and doesn‘t depend on surprise. And, in the long run, resistance to it is impossible.

Campbell concludes: "It seems to me that in that least developed of all fields of human understanding, the human mind itself, must lie the Ultimate Weapon. But there’s one comfort; whoever develops it will be our friend."

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