Harnessing Nature

Can the Free Energy of Space be Utilized?

In a few centuries the world’s coal mines will be exhausted. Whence shall we derive the energy to turn the wheels of industry? By harnessing nature, is the answer. Long before we took stock of our fuel supply and found that we must husband what little we have left, scientific dreamers wondered whether natural forces could not in some way be utilized. To be sure, the potential energy stored up in every combustible is a natural force; however artificial our engines may seem, their power is nevertheless ultimately obtained from the sun. But that power is released and applied only by complicated and cumbrous mechanism that wastes many times more energy than it delivers. Why should it not be possible to tap the free energy of space, the energy with which the sun, for example, incessantly bombards us? Can not some engine be devised to transform and make available the apparently inexhaustible supply of energy liberated by every atom of radium? To answer questions such as these with anything like satisfaction is impossible. Yet they are discussed by the most distinguished physicists of the day, and therefore they acquire a dignity with which they might not otherwise be invested. At the fourth annual meeting of the British Science Guild, for example, the whole vast subject of harnessing nature was considered and a committee of seventeen was appointed to report upon it. Among the members of that committee were such distinguished scientific men as Sir William Ramsay, Hon. R. J. Strutt, Prof. Vivian B. Lewes, Sir Charles A. Parsons, Mr. Dugald Clerk, and Dr. Hele Shaw. The committee has not yet handed in its final report, but it has done enough to show how wonderful are the possibilities of engineering when combustibles will no longer be available and along what lines the investigator must work if success is to be attained.

Water Power

The only natural source of free energy that engineers have thus far successfully utilized is water power. How they have gone to work is so old a story that it need not be retold here. Their task was simple. The crudest kind of bladed wheel ground corn centuries ago. The great turbines of Niagara Falls are merely improvements upon it.

A water fall is a ready-made solar engine, the only commercial solar engine that man has succeeded in utilizing. No machine has ever been designed or ever will be designed that will surpass the water fall in efficiency. The sun pumps the water of ocean, lake and river on mountain tops, and the force of gravity drops the water again to its original level. The cycle is endless. Because there are no valves, no shafts, no connecting rods, no thermal losses, the efficiency is one hundred per cent. It has been calculated that the total energy of these atmospheric deposits amounts to 100,000,000 horse-power. With the advent of electricity and its introduction into industry part at least of this energy is being used - the sole example of the successful use of nature’s free energy.

Putting the Sun to Work

But why not go directly to the sun? Its radiation has been measured and expressed in engineering units. In his Royal Institution lectures of 1911, Sir J. J. Thomson stated that, shining from a clear sky, the sun sends to the earth energy at the rate of 7,000 horse-power an acre. Moreover, as the temperature of the sun is at least 6,000 deg. Cent. this energy must arrive in a highly available condition; theoretically it ought to be almost wholly convertible into mechanical work. No wonder that the construction of a commercial solar engine has been one of the most fascinating problems that ever engaged the attention of inventors.

Up to within recent years the most elaborate experiments on record were those of Capt. John Ericsson, designer of the famous “Monitor.” On a rainless strip eight thousand miles long and one mile wide, extending almost continuously from Africa into Asia and from South America into the United States, solar heat enough is wasted, he figured, to drive 22,300,000 solar engines of one hundred horse-power each, nine hours a day.

In endeavoring to utilize a very small part of this truly staggering amount of wasted energy, Ericsson worked persistently from 1865 to 1878 and built in that time no less than seven sun engines. He adopted the rather obvious method of concentrating the sun’s rays on a boiler when he was driving his engine by steam, and on an air chamber when he employed one of his “caloric” engines. Eventually he succeeded in obtaining about one horse-power for every one hundred square feet of reflecting surface. Finally he came to the conclusion that the scheme was impracticable. “The fact is,” he frankly admitted, “that although the heat is obtained for nothing, so extensive, costly and complex is the concentration apparatus that solar steam is many times more costly than steam produced by burning coal.”

Since Ericsson’s day other attempts have been made along different lines. Readers of the Scientific American are familiar with the proposals of Mr. Frank Shuman, Prof. Reginald Fessenden, and Messrs. Willsie and J. Boyle, Jr. Because their apparatus has been described in these columns at sufficient length it is unnecessary to dwell upon it again. In all these three solar power plants, the “hot box” of de Saussure, Langley and other pioneer solar physicists is employed. In other words, a film of water is heated in a glass-covered trough. The heat impounded by the trough is sufficient to raise the water to the boiling point, or very near it. Mr. Shuman has designed a low-pressure steam engine in which this hot water is flashed into steam. Messrs. Willsie and Boyle employ their hot water to vaporize a liquid, which has a boiling point lower than that of the water, a liquid such as sulphur dioxide. The vapors which are given off from the sulphur dioxide at a pressure of 215 pounds to the square inch drive a specially designed engine and are then returned to be used over again. The water which has given up its heat to the sulphur dioxide is sent through the hot-box again to absorb more heat from the sun.

Since the sun does not shine by night even in the desert of Sahara, a storage system must be devised - a piece of apparatus that can be charged with excess power and tapped at will in sunless periods. Compressed air tanks, storage batteries charged by dynamos driven by the solar engine, water pumped into a reservoir by a solar pump and used later to drive a water wheel, have all been proposed. Messrs. Willsie and Boyle store their hot water in a well insulated tank, so that it retains its heat over night and is always hot enough to vaporize sulphur dioxide. Mr. Shuman has also designed an insulated tank or boiler for storing hot water.

Prof. Fessenden, in the solar power scheme described and illustrated in the Scientific American two years ago, considered it more expedient to pump water into a reservoir and let it drop a considerable height against a water wheel. He, too, heats his water in a thin film under glass, causes the steam thus generated to drive a low-pressure pump directly, and thus fills his reservoir with water. In the plant illustrated in the Scientific American he showed a way of lifting Channel water to the top of the Dover Cliffs, so that it would flow back through a pipe and drive a water turbine at the bottom of the cliff. In conjunction with each solar plant a windmill is to be operated, so that, as he explains, “much better all-day and all-year efficiency will be obtained, because the wind is, as a rule, more effective during cloudy weather and at night time, i. e., when solar radiation is diminished or absent.”

If we can extract heat from anything we can perform work. Water can be boiled without fire simply by reducing the pressure of the atmosphere. Since the atmosphere contains a certain amount of heat, why not extract it, as it were, and drive an engine? That is a proposal which Mr. Nikola Tesla has made. The direct utilization of the sun’s heat after the manner of Ericsson, Shuman, and others seems to him commercially hopeless, however practicable it may be on an experimental scale. Moreover, he cannot reconcile himself to the idea that the entire manufacturing interests of the world must be transplanted to Arizona, southern California, Egypt, or the Sahara desert when the world’s coal supply is exhausted and the solar engine is at last realized. Industry seems to be identified with the temperate zones, where sunshine is intermittent. The periodicity of sunshine, with which all solar engineers must reckon, he finds an insuperable difficulty. Moreover, it seems inept to him to convert the intense heat of the sun into low-temperature heat, of which only a small fraction can ever be recovered as mechanical work. In his opinion, the only direct way of converting solar energy into work is to tap the heat units of the atmosphere, heat units available at all times, in fair weather as well as foul, in summer as well as in winter. There is no need to invent storage systems; for the atmosphere is its own storage tank. This is, to be sure, but a thermodynamic dream as yet, but a dream which, however wild it may seem, is nevertheless worthy of at least academic discussion.

The Photo-Chemical Power Transformer

Every living organism is a crude kind of solar engine. We are all dependent on the product of the soil for our existence, and that product in turn represents so much solar energy chemically stored up. A grazing cow is a living engine that converts solar energy into work. The solar energy that has caused grass to grow is turned to practical account whenever she flicks a fly from her back. Prof. V. Coblentz has suggested that perhaps a chemical substance may be discovered, which, when exposed to the sun, is transformed into a stable substance capable of giving up its energy for subsequent consumption, a substance more highly efficient than grass and capable of releasing its energy perhaps in an electrical way.

This idea was further developed in a profound analysis of photo-chemical problems before the recent International Chemical Congress by the distinguished Italian chemist, Prof. Ciamician. An obvious cycle, he suggested, was the use of mineral fertilizers to raise a harvest, which, dried by the sun, could be converted entirely into gaseous fuel, the ammonia being fixed and returned to the soil as fertilizer, together with the ash. He also deemed it possible to produce the things we need directly without the intervention of much factory machinery, if ammonia can be directly obtained from atmospheric nitrogen and hydrogen - the recent technical achievement of a great German chemical manufacturing company - why should it not be possible, he asks, to utilize solar energy in connection with catalytic substances and thus artificially reproduce plant processes on an unprecedented scale? A photochemical laboratory in northern Africa might thus produce immediately useful substances now supplied only after much coal-burning, engine-driving and mechanical handling of raw material. A meadow is not a highly efficient transformer of solar energy, but the manner in which it synthesizes the chemical elements stored up in the earth with the aid of sunshine might well be artificially reproduced, and the solar engine itself abandoned except for purely thermodynamic purposes. If a plant can reverse the process of combustion, if it can transform the carbon dioxide of the atmosphere into starch, simultaneously setting free oxygen, why can’t man adopt the same principle with success? At all events, Prof. Ciamician holds that it lies within our power to make plants produce abundantly the things we need. The possibility is indicated when we consider the ease with which we have increased the amount of sugar in the sugar beet and the percentage of protein in wheat.

The Energy of the Rotating Earth

In an introductory lecture to the engineering classes at University College, London, Prof. J. A. Fleming, in considering the sources of energy available to mankind, pointed out that the earth is a great flywheel. It whirls along in its orbit with a velocity of about twenty miles a second or 1,200 times that of an express train. Its rotational energy is a hundred thousand million billion horse-power hours; but the total orbital energy or energy of motion in its orbit is ten thousand times greater. “Suppose,” said Prof. Fleming, “suppose we could in some way or other slow down its rotation so as to make the day just five minutes longer.... This would decrease the earth’s angular velocity by about one third of one per cent and decrease the angular energy by about two thirds of one per cent, or say by 1/150 part. If then we could capture and store up the difference in the rotational energy in the two cases, it would give us about six million billion horse-power hours, or a billion horse-power for seventy thousand years. The energy we can obtain by the combustion of all the one thousand million tons of coal at present raised per year, sinks into insignificance compared with the enormous energy which would be set free by an almost imperceptible lengthening of the earth’s diurnal rotation.”

Prof. Fleming was not rash enough to indicate in what manner this unthinkable amount of energy could be utilized. Those who will attempt that will find themselves engaged in the mad task of designing perpetual motion machines.

The Energy of the Atom

If Ramsay is correct in stating that copper and lead can be disintegrated, have we not here a source of energy? Sir William Ramsay has himself effectually disposed of that possibility. First, all metals, except gold and platinum, he has pointed out, are produced by the combustion of fuel, or, it may be, by electric power derived from turbines and dynamos. Hence they must be more costly than the means used in their production; to produce them, not merely must energy be used, but also some must be degraded, and lost as heat. Labor, too, is expended in their production. On the supposition of change with evolution of energy, they would give out no more than has been put in, in converting the ores into the metals. Lastly, supposing that this compound can be induced to change, under the action of ultra-violet light for example, the change is too slow to be effective as a source of energy; and ultra-violet light itself is produced only after much energy is expended.

Experiments conducted by Mr. Nikola Tesla with electromotive forces of 20,000,000 volts have convinced him that if 100,000,000 volts could be produced it might be possible to break down the atomic structure of any element and thus liberate a certain amount of energy. “But,” he told the writer of this article, “even if the feat could be accomplished and sufficient energy set free, there still remains the enormously difficult problem of devising a means of utilizing the energy in a practical way.”

Prof. J. A. Fleming suggests a somewhat similar course. “It is now pretty generally recognized,” he argues, “that an atom is a complicated structure, a sort of solar system in miniature composed of revolving electrons. It may be possible to break down the structure by the action of impulses due to concentrated electric waves of the right period, setting up vibrations, which are resonant with some natural period of the atom, just as it is possible to break down a suspension bridge by a number of men jumping on it in time with its natural period of oscillation. If then the atom were to break down, the energy liberated might be far greater than that applied to it in the form of the resonant impulses.”

Sir William Ramsay is undoubtedly right in maintaining that no source of energy, capable of being converted into work on a large scale, can be looked for, so far as the transmutation of matter is concerned. “The question is not - can it be done? but - does it pay to do it? And to the last question the answer is emphatically no.”

Radium as a Source of Energy

So minute a quantity of pure radium as one gramme (one twenty-eighth of an ounce) yields 118 calories an hour, 2,900 a day, or nearly one million a year. A ton of radium, according to Sir William Ramsay containing a million grammes, would give one million million calories per year. As one gramme of coal in burning evolves about 8,500 calories, one ton would evolve one million times as much, or 8,500,000,000, which is only the 117th part of that evolved by the radium in a year. Moreover, the radium after the year has suffered merely a minute loss of weight; roughly speaking, about 1/3,500th of its weight has disappeared; hence before it was all “consumed” it would have evolved 117 x 3,500 = 400,000 times as much heat as an equal weight of coal. Add to this the fact that coal is utterly consumed in a few hours, but that rate of change of radium is all but imperceptible, and the superiority of radium over coal, weight for weight, is still more apparent.

Unfortunately, radium is about the scarcest producer of energy in the whole world. Radium is the offspring of uranium; it does not occur apart from uranium. Sir William Ramsay places the supply of uranium in its ores ut about one million tons. Since the amount of uranium contained in the “kulm” shale of Sweden is under 0.5 per cent he concludes that the amount of radium metal in the whole world is not more than 500 pounds - too insignificant, in a word, for serious consideration as a substitute for coal. Not more than 125,000 tons of coal would be saved by utilizing the energy in 500 pounds of pure radium. The railway locomotives of the United States burn more than that quantity of fuel in a year. Besides, the energy in the five hundred pounds of radium cannot be liberated quickly, but must be spread over a period of centuries. The late Prof. Curie once remarked that he would not venture into a room containing only a pound of radium, so extraordinarily intense is its action. Hence, even if it were possible to hasten the discharge of radioactive energy, the engineers of a radium power plant would have to be recruited from the members of Stevenson’s Suicide Club.

The Internal Heat of the Earth

It is a matter of common knowledge that in sinking mining shafts there is a rise in temperature of about 1 deg. Fahr. for every 69 feet, down to a certain depth. Active volcanoes afford still more striking evidence of the earth’s internal heat. Have we not here an inexhaustible source of energy? We have, but it is difficult, if not impossible, to utilize it. If the prime requisite in making use of any source of heat is to obtain good conditions of thermal interchange with it, an insuperable obstacle would be found in the poor conducting qualities of rock. Only by fluid convection would it be remotely possible to obtain communication With the earth’s stores of heat. In considering these possibilities, the Hon. R. J. Strutt points out that hot springs, while they have been utilized from time immemorial, are too diminutive. The perpetual streams of molten lava that flow into the sea in certain localities, as at Stromboli, might perhaps be utilized, he ventures, “but the opportunities for applying the method would scarcely be extensive enough to encourage inventors.”

Why not pump water down to the heated interior and return it to the surface at a high temperature? Here again Strutt sees no possibilities. The pipes would have to be kept immersed in molten lava; no sufficiently rapid transference of heat to them from solid rock would be possible. For the same reason, he states, the pipes must not be cooled down by the water flowing through them sufficiently to cause the surrounding lava to congeal. Can the pipes endure the prolonged action of molten basalt? Wrought iron might in Strutt’s opinion. “On the other hand, the margin of difference between the melting point of basalt and of iron is not very great, and lack of stiffness in iron pipes at such temperatures would undoubtedly introduce the most serious difficulties.” Even if the attempt be made by directly attacking a volcanic crater the engineering difficulties would be enormous.

Similar conclusions were reached by Sir Charles A. Parsons in a presidential address to the engineering section of the British Association for the Advancement of Science. He discussed the feasibility of constructing a bore hole twelve miles deep. While the feat could be accomplished, and while the temperature of the rock at that depth is probably 272 deg. Fahr., the undertaking would involve an expenditure of millions.