Progress of Science: Scores of Death Ray Inventions Still Await First Demonstrations

Laboratories Produce Waves From Super-Sonic to Cosmic, But None Yet Proves Fatal

Dr. Nikola Tesla's Announcement He Has Invented Death Ray Recalls Many Have Sought Such a Device; Some Radiations, Such as X-Rays and Gamma Rays, Cause Burns, but Lack Range

Death rays — beams that kill animals and people at a distance and that annihilate airplane and battleships by merely impinging on them — have been invented by the score in recent years, according to announcements in the papers, but strangely enough not one has ever been demonstrated before credible witnesses. Nikola Tesla, the electrical
genius, on the occasion of his seventy-eighth birthday last week, joined the ranks of those who have invented death rays.

Tesla's earlier epoch-making accomplishments put him in an entirely separate class from the usual run of death-ray inventors. The other death rays, pending demonstration, can be classed as pure imaginative twaddle. If a death ran were possible, the principles used would be far more valuable for other than military purposes — their usual object.

Three Possible Groups

Although none of the death-ray inventors has ever released a description of his device or the principles upon which it operates, the claims advanced for them indicate that they are divided into three groups: First, a ray composed of some invisible kind of radiation of the same general nature as light and which has lethal properties; second, a ray which acts as a conductor of electricity and makes possible the sending of enormous voltages to a distant object that will disrupt a mechanism and prove fatal to living things; third, a ray composed of sub-atomic particles that disrupt the atomic structures of living and inanimate things.

Death rays of the first kind date back to ancient days and to the use of burning mirrors to focus heat rays on enemy galleys as they approached the land to set them afire.

Below the heat waves we have the short radio waves. These can be focussed into a beam but the amount of power transmitted infinitesimally small and harmless.

In the upper end of the spectrum are the ultra-violet rays. They are lethal to bacteria and too long an exposure to them will injure the eyes and produce physiological disturbances, but, as a death ray, they are quite ineffective. Ordinary window glass is a protection against them.

Gamma and X-Rays

Still higher we have the gamma and the X-ray. They have great penetrating power and can go through such dense material as metal. Because of this property they cannot be reflected by mirrors and focussed into a beam. Exposures to them for many hours at close range will produce serious burns and skin disorders, but as death-ray material they are ineffectual at a distance.

On the upped end of the scale we have the cosmic rays, which may be waves or extremely high speed particles. They can pass through lead thirteen feet thick and will, therefore, pass through any apparatus we may use to try to control or direct them so that they are not available These for the death-ray makers. cosmic rays have been shooting through our bodies at the rate of hundreds every second ever since we were born so we need have no particular fears concerning their use.

Before passing from the "wave" field reference should be made to super-sonic vibrations — or sound waves that are far above the range of the human ear. These were developed at the laboratories of Alfred L. Loomis, a millionaire amateur scientist, at Tuxedo Park. They are produced by the vibrations of a quartz crystal activated by currents of high frequency. Beyond a certain wave length they cannot be transmitted through the air, but water and solid substances will conduct them. When they were first produced in a tank containing some fish, the fish were instantly killed, their bodies being reduced to pulp. The vibrations lose their effectiveness over short distances.

Ionization Basis of Electrical Waves

Death rays that have as their purpose the conducting of a high voltage current to the object to be destroyed are based upon the idea that ionized air will conduct electricity better than ordinary air because of the presence of a large number of free electrons. Ultra-violet light, X-rays and gamma rays will ionize the air. Radium gives off gamma rays, but it is rare and its rays weak and difficult to control. X-rays can be directed by means of the target in the tube in which they are generated, but the beam would be too diffused for practical use. Ultra-violet light can quite easily be directed in a beam as is done with ordinary light in a searchlight beam.

An ultra-violet beam will ionize the air and make it a conductor for high voltage currents. As a laboratory stunt it works well over very short distances — measured in inches. But ultra-violet light has another property which would be very likely to defeat its use in a death ray. As it ionizes the air it produces ozone, and ozone is opaque to ultra-violet light, shutting off the light that creates it. If this did not happen in the atmosphere, thus providing a screen against the powerful ultra-violet light from the sun, it would be difficult for us to pass much time in the open.

Short Circuit for Ray

In addition we have the problem of a circuit for the high-voltage current — supposing that a conducting beam could be provided. The object at which the ray was directed would have to be grounded if a single ray were used. The object would, therefore, be close to the land or water, and the beam would likewise have to be close. Under these conditions the high-voltage current would jump from the beam to the ground before it reached the object. If the object were an airplane, two conducting beams would have to be focussed on it. Under such conditions the current would be much more likely to jump from one beam to the other at their point of contact and leave the object undamaged.

We now have left the death ray which is supposed to be composed of streams of sub-atomic particles. There is the quite well known electron accepted for many years as the smallest unit of matter. It is now known as the negatron to distinguish it from another particle, recently discovered and called the positron. Next we have the proton, with about 1,000 times the mass of a negatron. The neutron has about the same mass, but it is unique in that it possesses no electrical field, while the other particles carry either positive of negative charges that have important effects. Above this point the particles are of atomic dimensions, and mot useful in death rays, because they are stopped by a few inches of air ever when impelled by high voltages.

Streams of negatrons, known a (cathode rays, have been produced in "Vacuum tubes for many years in laboratories. One of their best known applications is the cathode ray oscillograph in which a ray no thicker than the lead in a pencil is caused to trace its path on a fluorescent screen. Even in this vacuum tube difficulty is experienced in keeping the beam from diffusing due to the mutually repellent nature of the particles which compose it.

Air Stops Negatrons

When a stream of negatrons is ejected out of a vacuum tube an into the open air as in the Lenard tube developed in the Westinghouse laboratories, or the Coolidge high voltage tube developed in the General Electric laboratories, their range is limited to a few feet, even at 600,000 volts. Positrons act the same way in the air, and the protons which are still more massive have a still shorter range. This eliminates all of the sub-atomic particles but one, the neutron.

The neutron is probably composed of a proton and a negatron in extremely close contact, so close that the positive field of the former is completely neutralized by the negative field of the latter. As the electrical field surrounding a particle is an effective part of its dimension the neutron lacking an external electric field becomes of extremely small effective size — very much smaller than an electron although its mass is about 1,000 times as great.

Because of its extremely small effective size the neutron has enormous penetrating powers for passing through matter. It can pass extremely close to the nucleus of an atom without disturbing the atom or being disturbed by it. It can pass through great thicknesses of matter with but very slight danger of making a direct hit on an atom. A stream of neutrons traveling at high speed would pass right through the air as if it were a perfect vacuum.

But what happens when this unhindered beam of high speed neutrons hits the target at which the hypothetical death ray is aimed? Nothing! The stream of neutrons passes right through the object without any effect whatever on it. Hundreds of millions would pass through before one would score a hit on an atom, and when this did happen the effect would be unobservable. The cosmic rays are producing the same effects on us and everything around us every second of the day and night.

Use of lightning is impractical. The landing tower of the Empire State Building has been hit by lightning hundreds of times without suffering the slightest damage.

All of the known possibilities of waves, currents and particles have been considered, and none of them offers any practical method by which a death ray could be engineered.

But we still have Dr. Tesla's statement that he has invented a death ray, and that cannot be disposed of by any process of reasoning that does not take into consideration the facts and observations upon which Dr. Tesla bases his predictions. These, however, he refuses to divulge. His predictions on electrical engineering developments from his early inventions have been magnificently fulfilled. Some of his earlier projects remain unfinished. He proposed many years ago a world-wide wireless distribution of electrical power. This would not be by radio, but was based upon the conducting power of an ionized strata of air in the upper atmosphere.

While the death ray ideas do not seem to fit into our present conception of things scientific, it must be kept in mind that our scientific theories have a habit of changing rapidly. If our present theories are due to be knocked into a cocked hat an experienced man like Dr. Tesla can do the job as well as any one.