bibliotecapleyades (Thanks, Vernie)

Tesla became familiar with the destructive characteristics of fireballs in his experiments at Colorado Springs in 1899. He produced them quite by accident and saw them, more than once, explode and shatter his tall mast and also destroy apparatus within his laboratory. The destructive action accompanying the disintegration of a fireball, he declared, takes place with inconceivable violence.

He studied the process by which they were produced, not because he wanted to produce them but in order to eliminate the conditions in which they were created. It is not pleasant, he related, to have fireballs explode in your vicinity for they will destroy anything they come in contact with.

At Colorado Springs….. I never saw fireballs, but as a compensation for my disappointment I succeeded later in determining the mode of their formation and producing them artificially.

Parasitic oscillations, or circuits, within the main circuit were a source of danger from this cause [of ball lightning]. Points of resistance in the main circuit could result in minor oscillating circuits between terminals or between two points of resistance and these minor circuits would have a very much higher period of oscillation than the main circuit and could be set into oscillation by the main current of lower frequency.

Even when the principle oscillating circuit was adjusted for the greatest efficiency of operation by the diminution of all sources of losses, the fireballs continued to occur, but these were due to stray high frequency charges from random earth currents.

From theses experiences it became apparent that the fire balls resulted from the interaction of two frequencies, a stray higher frequency wave imposed on the lower frequency free oscillation of the main circuit.

As the free oscillation of the circuit builds up from the zero point to the quarter wave length node it passes through various rates of change. In a current of shorter wavelength the rates of change will be steeper. When the two currents react on each other the resultant complex will contain a wave in which there is an extremely steep rate of change, and for the briefest instant currents may move at a tremendous rate, at the rate of millions of horsepower.

This condition acts as a trigger which may cause the total energy of the powerful longer wave to be discharged in an infinitesimally small interval of time and at a proportionately tremendously great rate of energy movement which cannot confine itself to the metal circuit and is released into surrounding space with inconceivable violence.

It is but a step, from learning how a high frequency current can explosively discharge a lower frequency current, to using the principle to design a system in which these explosions can be produced by intent.

The following process appears a possible one but no evidence is available that it is the one Tesla evolved: An oscillator, such as he used to send power wirelessly around the earth at Colorado Springs, is set in operation at a frequency to which a given warship is resonant. The complex structure of a ship would provide a great number of spots in which electrical oscillations will be set up of a much higher frequency than those coursing through the ship as a whole.

These parasite currents will react on the main current causing the production of fireballs which by their explosions will destroy the ship, even more effectively than the explosion of the magazine which would also take place. A second oscillator may be used to transmit the shorter wavelength current.

In the highly resonant transformer secondary comprising the magnifying transmitter, the entire energy accumulated in the excited circuit, instead of requiring a quarter period for transformation from static to kinetic, could spend itself in less time, at hundreds of thousands of horsepower. Thus for example, producing artificial fireballs by suddenly causing the impressed oscillations to be more rapid than free ones of the secondary. This shifted the point of maximum electrical pressure below the elevated terminal capacity and a ball of fire would leap great distances.

…if the points of maximum pressure should be shifted below the terminal, along the coil, a ball of fire might break out and destroy the support or anything else in the way. For the better appreciation of the nature of this danger it should be stated, that the destructive action may take place with inconceivable violence. This will cease to be surprising when it is borne in mind, that the entire energy accumulated in the excited circuit, instead of requiring, as under normal working conditions, one quarter of the period or more for its transformation from static to kinetic form, may spend itself in an incomparably smaller interval of time, at the rate of many millions of horsepower.

The accident is apt to occur when, the transmitting circuit is being strongly excited, the impressed oscillations upon it are caused, in any manner more or less sudden, to be more rapid than the free oscillations. [also thought that stray high frequency earth currents were also interacting with lower frequency transmitter currents]

When the action is very energetic, owing to the power of the streamer and other causes, the luminous portion of the same becomes a veritable fireball. This observation which, to my greatest astonishment, I have frequently observed in experiments with this apparatus, shows now clearly how fireballs are produced in lightning discharges and their nature is now quite plain.

With the present experiences I am satisfied that the phenomenon of the fireball is produced by the sudden heating. to high incandescence, of a mass of air or other gas as the case may be, by the passage of a powerful discharge. There are many ways or less plausible in which a mass of air might be thus affected by the spark discharge, but I hold the following explanation of the mode of production of the ball as being, most likely of all others which I have considered, the true one.

When sudden and very powerful discharges pass through the air, the tremendous expansion of some portions of the latter and subsequent rapid cooling and condensation gives rise to the creation of partial vacua in the places of greatest development of heat. These vacuous spaces, owing to the properties of the gas, are most likely to assume the shape of hollow spheres when, upon cooling, the air from all around rushes in to fill the cavity created by the explosive dilatation and subsequent contraction.

Suppose now that this result would have been produced by one spark or streamer discharge and that now a second discharge, and possible many more, follows in the path of the first. What will happen? Before answering the question we must remember that, contrary to existing popular notions, the currents passing through the air have the strength of many hundreds and even thousands of amperes.

A single powerful streamer, breaking out from a well insulated terminal, may easily convey a current of several hundred amperes!

No wonder then, that a small mass of air is exploded with an effect similar to that of a bombshell, as noted in many lightning discharges.

But to return now to the explanation of the fireball, let us now assume that such a powerful streamer or spark discharge, in its passage through the air, happens to come upon a vacuous sphere or space formed in the manner described. This space, containing gas highly rarefied, may be just in the act of contracting, at any rate, the intense current, passing through the rarefied gas suddenly raises the same to an extremely high temperature, all the higher as the mass of the gas is very small.

But although the gas may have been brought to vivid incandescence, yet its pressure may not be very great. If, upon the sudden passage of the discharge, the pressure of the heated air exceeds that of the air around, the luminous ball or space will expand, but most generally it may not do so.

For assume, for instance, that the air in the vacuous space was at one hundredth say, of its normal pressure, which might well be the case, then, since the pressure in the space would be as the absolute temperature of the gas within, it would require a temperature which seems scarcely realizable, to raise the pressure of the rarefied gas to the normal air pressure. It is therefore reasonable to expect that, despite the high incandescence of the rarefied air, the space filled with the same will continue to contract, and here an important consideration presents itself.

When, as before explained, the vacuous space was formed, the spark or streamer passed through the air disruptively, therefore the path was necessarily very thin, threadlike, and the minute quantity of the air which served as a conductor for the current was expanded with explosive violence to many thousand times its original volume.

Owing to the fact, however, that the quantity of mailer (??) through which the current was conveyed was small, a great facility was offered for giving off the heat so that the highly expanded gas-owing to its expansion arid (??) to radiation and convection of heat-cooled instantly. But how is it when the second discharge and possibly many subsequent ones pass through the rarefied gas?

These discharges find the gas already expanded and in a condition to take up much more energy by reason of the properties it acquires through rarefaction. Evidently, the energy consumption in any given part of the path of the streamer or spark discharge is, under otherwise the same conditions, proportionate to the resistance of that part of the path; and since, after the gas has once broken down, the resistance of other parts of the path of the discharge is much smaller than that including the vacuous space, a comparatively very great energy consumption must necessarily take place in this portion of the current path.

Here, then, is a mass of gas heated to high incandescence suddenly but not, as before, in a condition to give up heat rapidly. It can not cool down rapidly by expansion, as when the vacuous space was being formed, nor can it give off much heat by convection. To some extent even radiation is diminished.

On the contrary, despite the high temperature, it is compelled to confinement in a limited space which is continuously shrinking instead of expanding. All these causes cooperate in maintaining, for a comparatively long period of time, the gas confined in this space at an elevated temperature, in a state of high incandescence, in the case under consideration. Thus it is that the phenomenon of the ball is produced and the same made to persist for a perceptible fraction or interval of time.

As might be expected, the incandescent mass of gas in a medium violently agitated, could not possibly remain in the same place but will be, as a rule, carried, in some direction or other, by the currents of the air. Upon little reflection, however, we are led to the conclusion that the ball or incandescent mass, of whatever shape it be, will always move from the place where an explosion occurred first, to some place where such an explosion occurred later.

In fact, all observers concur in the opinion that such a fireball moves slowly. If we interpret the nature of this wonderful phenomenon in this manner, we shall find it quite natural that when such a ball encounters in its course an object, as a piece of organic matter for instance, it will raise the same to a high temperature, thus liberating suddenly a great quantity of gas by evaporating or volatilizing the substance with the result of being itself dissipated or exploded.

Obviously, also, it may be expected that the conducting mass of the ball originated as described, and moving through a highly insulating medium, will be likely to be highly electrified, which accords with many of the observations made. A better knowledge of this phenomenon will be obtained by following up experiments with still more powerful apparatus which is in a large measure already settled upon and will be constructed as soon as time and means will permit. There may be a way, however, of intensifying in this respect, the action of the present machine.

He mentions the splitting of streamers near the floor, splitting and reuniting, the phenomenon of luminous parts on the streamers (which he then refers to as sparks), and the breaking up of sparks into streamers and fireballs. His remarks concerning the genesis of fireballs are particularly noteworthy.

A fireball is a luminous sphere occurring during a thunderstorm. Fireballs are usually red, but other colors have also been observed: yellow, green, white and blue. Their dimensions vary, a mean diameter being about 25 cm. Unlike ordinary lightning, fireballs move slowly, almost parallel to the ground. They sometimes stop and change their direction of motion. They can last for up to 5 seconds.

Their properties vary greatly from case to case, so that it is believed that there are various types. Tesla mentions phenomena of this type several times as the result of sparks or streamers striking wooden objects.

It has been found that to maintain, a lump of plasma in air requires a power of the electromagnetic field of about 500 W, which is much less than power which can be produced by an electrical discharge. However, too little is known about natural electromagnetic waves to allow any reliable conclusions to be drawn.

Tesla’s hypothesis on the origin and maintenance of fireballs includes some points which are also to be found in the most recent theories, but it also bears the stamp of the time. For instance, Tesla considers that the initial energy of the nucleus is not sufficient to maintain the fireball, but that there must be an external source of energy.

According to Tesla this energy comes from other lightnings passing through the nucleus, and the concentration of energy occurs because of the resistance of the nucleus, i.e. the greater energy-absorbing capacity of the rarefied gas than the surrounding gas through which the discharge passes.

References

• FBI’s Freedom of Information Act Web Page..http://www.fbi.gov/foipa/main.htm – Look for Tesla in the Alpha Listings…Page 113
• US Patent #1,119,732 – Nikola Tesla, Apparatus for Transmitting Electrical Energy
• Colorado Springs Notes, N.Tesla – pages 368-372, 431-432 (purported to have 20 pages worth of ball lightning info??)
• “PRODIGAL GENIUS The Life of Nikola Tesla”, John J. O’Neill – page 183, and unpublished chapter 34
• “Tesla: Man Out of Time”, Margaret Cheney – pages 3-4, 281-282
• “The New Wizard of the West”, Chauncey McGovern, Pearson’s Magazine, London, May 1899
•  “Lightning In His Hand”, Inez Hunt & W.W. Draper