Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization

First Edition

© 1975-1979, 2008 Robert A. Freitas Jr. All Rights Reserved.

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; http://www.xenology.info/Xeno.htm


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.


Last updated on 6 December 2008