BEYOND OUR POWER
Useful and Latent Forces.--Connexion between Mass, Energy, and Velocity
of Light.--Deriving Power by Combustion.--One Gramme of Coal.--Unobtainable
Calories.--Economics of Coal.--Hopes and Fears.--Dissociated Atoms.
_29th March_ 1920
WE spoke of the forces that are available for man and which he derives
from Nature as being necessary for his existence and for the development
of life. What forces are at our disposal? What hopes have we of
elaborating our supply of these forces?
Einstein first explained the conception of energy, which is intimately
connected with the conception of mass itself. Every amount of substance
(I am paraphrasing his words), the greatest as well as the smallest, may
be regarded as a store of power, indeed, it is essentially identical
with energy. All that appears to our senses and our ordinary
understanding as the visible, tangible mass, as the objective body
corresponding to which we, in virtue of our individual bodies, abstract
the conceptual outlines, and become aware of the existence of a definite
copy is, from the physical point of view, a complex of energies. These
in part act directly, in part exist in a latent form as strains which,
for us, begin to act only when we release them from their state of
strain by some mechanical or chemical process, that is, when we succeed
in converting the potential energy into kinetic energy. It may be said,
indeed, that we have here a physical picture of what Kant called the
"thing in itself." Things as they appear in ordinary experience are
composed of the sum of our direct sensations; each thing acts on us
through its outline, colour, tone, pressure, impact, temperature,
motion, chemical behaviour, whereas the thing in itself is the sum-total
of its energy, in which there is an enormous predominance of those
energies which remain latent and are quite inaccessible in practice.
But this "thing in itself," to which we shall have occasion to refer
often with a certain regard to its metaphysical significance, may be
calculated. The fact that it is possible to calculate it takes its
origin, like many other things which had in no wise been suspected, in
Einstein's Theory of Relativity.
Quite objectively and without betraying in the slightest degree that an
astonishing world-problem was being discussed, Einstein expressed
himself thus:
"According to the Theory of Relativity there is a calculable relation
between mass, energy, and the velocity of light. The velocity of light
(denoted by _c_, as usual) is equal to 3.10^10 cm. per second.
Accordingly the square of _c_ is equal to 9 times 10^20 cm. per second,
or, in round numbers, 10^21 cm. per second. This _c_^2 plays an
essential part if we introduce into the calculation the mechanical
equivalent of heat, that is, the ratio of a certain amount of energy to
the heat theoretically derivable from it; we get for each gramme
20.10^12, that is, 20 billion calories."
We shall have to explain the meaning of this brief physical statement in
its bearing on our practical lifes. It operates with only a small array
of symbols, and yet encloses a whole universe, widening our perspective
to a world-wide range!
To simplify the reasoning and make it more evident we shall not think of
the conception of substance as an illimitable whole, but shall fix our
ideas on a definite substance, say coal.
There seems little that may strike us when we set down the words:
"One Gramme of Coal."
We shall soon see what this one gramme of coal conveys when we translate
the above-mentioned numbers into a language to which a meaning may be
attached in ordinary life. I endeavoured to do this during the above
conversation, and was grateful to Einstein for agreeing to simplify his
argument by confining his attention to the most valuable fuel in our
economic life.
Once whilst I was attending a students' meeting, paying homage to
Wilhelm Dove, the celebrated discoverer took us aback with the following
remark: When a man succeeds in climbing the highest mountain of Europe
he performs a task which, judged from his personal point of view,
represents something stupendous. The physicist smiles and says quite
simply, "Two pounds of coal." He means to say that by burning 2 lb. of
coal we gain sufficient energy to lift a man from the sea-level to the
summit of Mont Blanc.
It is assumed, of course, that an ideal machine is used, which converts
the heat of combustion without loss into work. Such a machine does not
exist, but may easily be imagined by supposing the imperfections of
machines made by human hands to be eliminated.
Such effective heat is usually expressed in calories. A calorie is the
amount of heat that is necessary to raise the temperature of a gramme of
water by one degree centigrade. Now the theorem of the Mechanical
Equivalent, which is founded on the investigations of Carnot, Robert
Mayer, and Clausius, states that from one calorie we may obtain
sufficient energy to lift a pound weight about 3 feet. Since 2 lb. of
coal may be made to yield 8 million calories, they will enable us to
lift a pound weight through 24 million feet, theoretically, or, what
comes to the same approximately, to lift a 17-stone man through 100,000
feet, that is, nearly 19 miles: this is nearly seven times the height of
Mont Blanc.
At the time when Dove was lecturing, Einstein had not yet been born, and
when Einstein was working out his Theory of Relativity, Dove had long
passed away, and with him there vanished the idea of the small value of
the energy stored in substance to give way to a very much greater value
of which we can scarce form an estimate. We should feel dumbfounded if
the new calculation were to be a matter of millions, but actually we are
to imagine a magnification to the extent of billions. This sounds almost
like a fable when expressed in words. But a million is related to a
billion in about the same way as a fairly wide city street to the width
of the Atlantic Ocean. Our Mont Blanc sinks to insignificance. In the
above calculation it would have to be replaced by a mountain 50 million
miles high. Since this would lead far out into space, we may say that
the energy contained in a kilogramme of coal is sufficient to project a
man so far that he will never return, converting him into a human comet.
But for the present this is only a theoretical store of energy which
cannot yet be utilized in practice.
Nevertheless, we cannot avoid it in our calculations just as we cannot
avoid that remarkable quantity _c_, the velocity of light that plays its
part in the tiny portion of substance as it does in everything,
asserting itself as a regulative factor in all world phenomena. It is a
natural constant that preserves itself unchanged as 180,000 miles per
second under all conditions, and which truly represents what appeared to
Goethe as "the immovable rock in the surging sea of phenomena," as a
phantasm beyond the reach of investigators.
It is difficult for one who has not been soaked in all the elements of
physical thought to get an idea of what a natural constant means; so
much the more when he feels himself impelled to picture the constant, so
to speak, as the rigid axis of a world constructed on relativity.
Everything, without exception, is to be subjected not only to continual
change (and this was what Heraclitus assumed as a fundamental truth in
his assertion _panta rhei_, everything flows), but every
length-measurement and time-measurement, every motion, every form and
figure are dependent on and change with the position of the observer, so
that the last vestige of the absolute vanishes from whatever comes into
the realm of observation. Nevertheless, there is an absolute despot, who
preserves his identity inflexibly among all phenomena--the velocity of
light, _c_, of incalculable influence in practice and yet capable of
measurement. Its nature has been characterized in one of the main
propositions of Einstein stated in 1905: "Every ray of light is
propagated in a system at rest with a definite, constant velocity
independent of whether the ray is emitted by a body at rest or in
motion." But this constancy of the omnipotent _c_ is not only in
accordance with world relativity: it is actually the main pillar which
supports the whole doctrine; the further one penetrates into the theory,
the more clearly does one feel that it is just this _c_ which is
responsible for the unity, connectivity, and invincibility of Einstein's
world system.
In our example of the coal, from which we started, _c_ occurs as a
square, and it is as a result of multiplying 300,000 by itself (that is,
forming _c_^2) that we arrive at the thousands of milliards of energy
units which we associated above with such a comparatively insignificant
mass. Let us picture this astounding circumstance in another way,
although we shall soon see that Einstein clips the wings of our soaring
imagination. The huge ocean liner _Imperator_, which can develop a
greater horsepower than could the whole of the Prussian cavalry before
the war, used to require for one day's travel the contents of two very
long series of coal-trucks (each series being as long as it takes the
strongest locomotive to pull). We now know that there is enough energy
in two pounds of coal to enable this boat to do the whole trip from
Hamburg to New York at its maximum speed.
I quoted this fact, which, although it sounds so incredibly fantastic,
is quite true, to Einstein with the intention of justifying the opinion
that it contained the key to a development which would initiate a new
epoch in history and would be the panacea of all human woe. I drew an
enthusiastic picture of a dazzling Utopia, an orgy of hopeful dreams,
but immediately noticed that I received no support from Einstein for
these visionary aspirations. To my disappointment, indeed, I perceived
that Einstein did not even show a special interest in this circumstance
which sprang from his own theory, and which promised such bountiful
gifts. And to state the conclusion of the story straight away I must
confess that his objections were strong enough not only to weaken my
rising hopes, but to annihilate them completely.
Einstein commenced by saying: "At present there is not the slightest
indication of when this energy will be obtainable, or whether it will be
obtainable at all. For it would presuppose a disintegration of the atom
effected at will--a shattering of the atom. And up to the present there
is scarcely a sign that this will be possible. We observe atomic
disintegration only where Nature herself presents it, as in the case of
radium, the activity of which depends upon the continual explosive
decomposition of its atom. Nevertheless, we can only establish the
presence of this process, but cannot produce it; Science in its present
state makes it appear almost impossible that we shall ever succeed in so
doing."
The fact that we are able to abstract a certain number of calories from
coal and put them to practical use comes about owing to the circumstance
that combustion is only a molecular process, a change of configuration,
which leaves fully intact the atoms of which the molecules are composed.
When carbon and oxygen combine, the elementary constituent, the atom,
remains quite unimpaired. The above calculation, "mass multiplied by the
square of the velocity of light;" would have a technical significance
only if we were able to attack the interior of the atom; and of this
there seems, as remarked, not the remotest hope.
Out of the history of technical science it might seem possible to draw
on examples contradictory to this first argument which is soon to be
followed by others equally important. As a matter of fact, rigorous
science has often declared to be impossible what was later discovered to
be within the reach of technical attainment--things that seem to us
nowadays to be ordinary and self-evident. Werner Siemens considered it
impossible to fly by means of machines heavier than air, and Helmholtz
proved mathematically that it was impossible. Antecedent to the
discovery of the locomotive the "impossible" of the academicians played
an important part; Stephenson as well as Riggenbach (the inventors of
the locomotive) had no easy task to establish their inventions in the
face of the general reproach of craziness hurled at them. The eminent
physicist Babinet applied his mathematical artillery to demolish the
ideas of the advocates of a telegraphic cable between Europe and
America. Philipp Reis, the forerunner of the telephone, failed only as a
result of the "impossible" of the learned physicist Poggendorff; and
even when the practical telephone of Graham Bell (1876) had been found
to work in Boston, on this side of the Atlantic there was still a hubbub
of "impossible" owing to scientific reasons. To these illustrations is
to be added Robert Mayer's mechanical equivalent of heat, a determining
factor in our above calculations of billions; it likewise had to
overcome very strong opposition on the part of leading scientists.
Let us imagine the state of mankind before the advent of machines and
before coal had been made available as a source of power. Even at that
time a far-seeing investigator would have been able to discover from
theoretical grounds the 8000 calories mentioned earlier and also their
transformation into useful forces. He would have expressed it in another
way and would have got different figures, but he would have arrived at
the conclusion: Here is a virtual possibility which must unfortunately
remain virtual, as we have no machine in which it can be used. And
however far-sighted he may have been, the idea of, say, a modern dynamo
or a turbine-steamer would have been utterly inconceivable to him. He
would not have dreamed such a thing. Nay, we may even imagine a human
being of the misty dawn of prehistoric ages, of the diluvial period, who
had suddenly had a presentiment of the connexion between a log of wood
and the sun's heat, but who was yet unaware of the uses of fire; he
would argue from his primordial logic that it was not possible and never
would be possible to derive from the piece of wood something which sends
out warmth like the sun.
I believe now, indeed, that we have grounds for considering ourselves
able to mark off the limits of possibility more clearly than the present
position of science would seem to warrant. There is the same relation
between such possibilities and absolute impossibilities as there is
between Leibniz's _vérités de fait_ and the _vérités éternelles_.
The fact that we shall never succeed in constructing a plane isosceles
triangle with unequal base angles is a _vérité éternelle_. On the
other hand, it is only a _vérité de fait_ that science is precluded
from giving mortal man eternal life. This is only improbable in the
highest degree, for the fact that, up to the present, all our ancestors
have died is only a finite proof. The well-known Cajus of our logic
books need not die; the chances of his dying are only _n_⁄_n_+1, where
we denote the total of all persons that have passed away up to this
moment by _n_. If I ask a present-day authority in biology or medicine
what evidence there is that it will be possible to preserve an
individual person permanently from death, he would confess: not the
slightest. Nevertheless, Helmholtz declared: "To a person who tells me
that by using certain means the life of a person may be prolonged
indefinitely I can oppose my extreme disbelief, _but I cannot contradict
him absolutely_."
Einstein himself once pointed out to me such very remote possibilities;
it was in connexion with the following circumstance. It is quite
impossible for a moving body ever to attain a velocity greater than that
of light, because it is scientifically inconceivable. On the other hand,
it is conceivable, and therefore within the range of possibility, that
man may yet fly to the most distant constellations.
There is, therefore, no absolute contradiction to the notion of making
available for technical purposes the billions of calories that occurred
in our problem. As soon as we admit it as possible for discussion, we
find ourselves inquiring what the solution of the problem could signify.
In our intercourse we actually arrived at this question, and discovered
the most radical answer in a dissertation which Friedrich Siemens has
written about coal in general without touching in the slightest on these
possibilities of the future. I imagine that this dissertation was a big
trump in my hand, but had soon to learn from the reasoned contradiction
of Einstein that the point at issue was not to be decided in this way.
Nevertheless, it will repay us to consider these arguments for a moment.
Friedrich Siemens starts from two premises which he seemingly bases on
scientific reasoning, thus claiming their validity generally. They are:
Coal is the measure of all things. The price of every product
represents, directly or indirectly, the value of the coal contained in
it.
As all economic values in over-populated countries are the result of
work, and as work presupposes coal, capital is synonymous with coal. The
economic value of each object is the sum-total of the coal that had to
be used to manufacture the object in question. In over-populated states
each wage is the value of the coal that is necessary to make this extra
life possible. If there is a scarcity of coal, the wages go down in
value; if there is no coal, the wages are of no value at all, no matter
how much paper money be issued.
As soon as agriculture requires coal (this occurs when it is practised
intensively and necessitates the use of railways, machines, artificial
manures), coal becomes involved with food-stuffs. Thanks to
industrialism, coal is involved in clothing and housing, too.
Since money is equivalent to coal, proper administration of finance is
equivalent to a proper administration of coal resources, and our
standard of currency is in the last instance a coal-currency. Gold as
money is now concentrated coal.
The most advanced people is that which derives from one kilogramme of
coal the greatest possibilities conducive to life. Wise statesmanship
must resolve itself into wise administration of coal. Or, as it has been
expressed in other words elsewhere: "We must think in terms of coal."
These fundamental ideas were discussed, and the result was that Einstein
admitted the premises in the main, but failed to see the conclusiveness
of the inferences. He proved to me, step by step, that Siemens' line of
thought followed a vicious circle, and, by begging the question, arrived
at a false conclusion. The essential factor, he said, is man-power, and
so it will remain; it is this that we have to regard as the primary
factor. Just so much can be saved to advantage as there is man-power
available for purposes other than for the production of coal from which
they are now released. If we succeed in getting greater use out of a
kilogramme of coal by better management, then this is measurable in
man-power, with which one may dispense for the mining of coal, and which
may be applied to other purposes.
If the assertion: "Coal is the measure of all things," were generally
valid, it should stand every test. We need only try it in a few
instances to see that the thesis does not apply. For example, said
Einstein: However much coal we may use, and however cleverly we may
dispose of it, it will not produce cotton. Certainly the freightage of
cotton-wool could be reduced in price, but the value-factor represented
by man-power can never disappear from the price of the cotton.
The most that can be admitted is that an increase of the amount of power
obtained from coal would make it possible for more people to exist than
is possible at present, that is, that the margin of over-population
would become extended. But we must not conclude that this would be a
boon to mankind. "A maximum is not an optimum."
He who proclaims the maximum without qualification as the greatest
measure of good is like one who studies the various gases in the
atmosphere to ascertain their good or bad effect on our breathing, and
arrives at the conclusion: the nitrogen in the air is harmful, so we
must double the proportion of oxygen to counteract it; this will confer
a great benefit on humanity!
[1]*Armed with this striking analogy, we can now subject the foundation
of Siemens' theory to a new scrutiny, and we shall then discover that
even the premises contain a trace of the _petitio principii_ that
finally receives expression in the radical and one-sided expression:
"Coal is everything."
[Footnote 1: The parts included between *...* are to be regarded as
supplementary portions intended to elucidate the arguments involved in
the dialogue. In many points they are founded on utterances of Einstein,
but also contain reflections drawn from other sources, as well as
opinions and inferences which fall to the account of the author, as
already remarked in the preface. One will not get far by judging these
statements as right or wrong, for even the debatable view may prove
itself to be expeditious and suggestive in the perspective of these
conversations. Wherever it was possible, without the connexion being
broken, I have called attention to the parts which Einstein corrected or
disapproved of. In other places I refrained from this, particularly when
the subject under discussion demanded an even flow of argument. It would
have disturbed the exposition if I had made mention of every
counter-argument of the opposing side in all such cases while the
explanation was proceeding along broad lines.]
As if built on solid foundations this first statement looms before us:
Coal is solar energy. This is so far indisputable. For all the coal
deposits that are still slumbering in the earth were once stately
plants, dense woods of fern, which, bearing the burden of millions of
years, have saved up for us what they had once extracted as nutrition
from the sun's rays. We may let the parallel idea pass without
contention: In the beginning was not the Word, nor the Deed, but, in the
beginning was the Sun. The energy sent out by the sun to the earth for
mankind is the only necessary and inevitable condition for deeds. Deeds
mean work, and work necessitates life. But we immediately become
involved in an unjustifiable subdivision of the idea, for the propounder
of the theory says next: "... Coal is solar energy, therefore coal is
necessary if we are to work ..." and this has already thrust us from the
paths of logic; the prematurely victorious ergo breaks down. For, apart
from the solar energy converted into coal, the warmth of our mother
planet radiates on us, and furnishes us with the possibility of work.
Siemens' conclusion, from the point of view of logic, is tantamount to;
Graphite is solar energy; hence graphite is necessary, if we are to be
able to work. The true expression of the state of affairs is: Coal is,
for our present conditions of life, the most important, if not the
exclusive, preliminary for human work.
And when we learn from political economy that "in a social state only
the necessary human labour and the demand for power-installations which
require coal, and hence again labour for their production, come into
question," this in no way implies the assertion, as Siemens appears to
assume, that coal can be made out of labour. But it does signify that
work founded on the sun's energy need not necessarily be reducible to
coal. And this probably coincides with Einstein's opinion, which is so
much the more significant, as his own doctrine points to the highest
measure of effect in forces, even if only theoretically.*
Nevertheless, it is a fact that every increase in the quantity of power
derived, when expressed per kilo, denotes a mitigation of life's
burdens; it is only a question of the limits involved.
Firstly, is technical science with its possibilities, as far as they can
be judged at present, still able to guarantee the future for us? Can it
spread out the effective work so far that we may rely peacefully on the
treasures of coal slumbering in the interior of the earth?
Evidently not. For in this case we are dealing with quantities that may
be approximately estimated. And even if we get three times, nay ten
times, as many useful calories as before, there is a parallel
calculation of evil omen that informs us: there will be an end to this
feast of energy.
In spite of all the embarrassments due to the present shortage of coal
we have still always been able to console ourselves with the thought
that there is really a sufficiency, and that it is only a question of
overcoming stoppages. It is a matter of fact that from the time of the
foundation of the German Empire to the beginning of the World War coal
production had been rising steadily, and it was possible to calculate
that in spite of the stupendous quantities that were being removed from
the black caves of Germany, there remained at least 2000 milliards of
marks in value (taken at the nominal rate, that is, £100,000,000,000).
Nevertheless, geologists and mining experts tell us that our whole
supply will not last longer than 2000 years, in the case of England 500
years, and in that of France 200 years. Even if we allow amply for the
opening up of new coal-fields in other continents, we cannot get over
the fact that in the prehistoric fern forests the sun has stored up only
a finite, exhaustible amount of energy, and that within a few hundred
years humanity will be faced with a coal famine.
Now, if coal were really the measure of all things, and if the
possibility of life depended only on the coal supply, then our distant
descendants would not only relapse into barbarity, but they would have
to expect the absolute zero of existence. We should not need to worry at
all about the entropy death of the universe, as our own extinction on
this earthly planet beckons to us from an incomparably nearer point of
time.
At this stage of the discussion Einstein revealed prospects which were
entirely in accordance with his conviction that the whole argument based
on the coal assumption was untenable. He stated that it was by no means
a Utopian idea that technical science will yet discover totally new ways
of setting free forces, such as using the sun's radiation, or water
power, or the movement of the tides, or power reservoirs of Nature,
among which the present coal supply denotes only one branch. Since the
beginning of coal extraction we have lived only on the remains of a
prehistoric capital that has lain in the treasure-chests of the earth.
It is to be conjectured that the interest on the actual capital of force
will be very much in excess of what we can fetch out of the depositories
of former ages.
To form an estimate of this actual capital, entirely independent of
coal, we may present some figures. Let us consider a tiny water canal, a
mere nothing in the watery network of the earth, the Rhine-falls at
Schaffhausen, that may appear mighty to the beholder, but only because
he applies his tourist's measure instead of a planetary one. But even
this bagatelle in the household of Nature represents very considerable
effectual values for us: 200 cubic metres spread over a terrace 20
metres high yield 67,000 horse-power, equivalent to 50,000 kilowatts.
This cascade alone would suffice to keep illuminated to their full
intensity 1,000,000 glowlamps, each of 50 candle-power, and according to
our present tariff we should have to pay at least 70,000 marks (£3500
nominally) per hour. The coal-worshipper will be more impressed by a
different calculation. The Rhine-falls at Schaffhausen is equivalent in
value to a mine that yields every day 145 tons of the finest brown coal.
If we took the Niagara Falls as an illustration, these figures would
have to be multiplied by about 80.
And by what factor would we have to multiply them, if we wished to get
only an approximate estimate of the energy that the breathing earth
rolls about in the form of the tides? The astronomer Bessel and the
philosopher-physicist Fechner once endeavoured to get at some
comparative picture of these events. It required 360,000 men twenty
years to build the greatest Egyptian pyramid, and yet its cubical
contents are only about the millionth of a cubic mile, and perhaps if we
sum up everything that men and machinery have moved since the time of
the Flood till now, a cubic mile would not yet have been completed. In
contrast with this, the earth in its tidal motion moves 200 cubic miles
of water from one quadrant of the earth's circumference to another _in
every quarter of a day_. From this we see at once that all the
coal-mines in the world would mean nothing to us if we could once
succeed in making even a fraction of the pulse-beat of the earth
available for purposes of industry.
If, however, we should be compelled to depend on coal, our imaginations
cling so much more closely to that enormous quantity given by the
expression _mc_^2, which was derived from the theory of relativity.
The 20 billion calories that are contained in each gramme of coal
exercise a fascination on our minds. And although Einstein states that
there is not the slightest indication that we shall get at this supply,
we get carried along by an irresistible impulse to picture what it would
mean if we should actually succeed in tapping it. The transition from
the golden to the iron age, as pictured in Hesiod, Aratus, and Ovid,
takes shape before our eyes, and following our bent of continuing this
cyclically, we take pleasure in fancying ourselves being rescued from
the serfdom of the iron and of the coal age to a new golden age. A
supply, such as is piled up in an average city storing-place, would be
sufficient to supply the whole world with energy for an immeasurable
time. All the troubles and miseries arising from the running of
machines, the mechanical production of wares, house-fires would vanish,
and all the human labour at present occupied in mining coal would become
free to cultivate the land, all railways and boats would run almost
without expense, an inconceivable wave of happiness would sweep over
mankind. It would mean an end of coal-, freight-, and food-shortage! We
should at last be able to escape out of the hardships of the day, which
is broken up by strenuous work, and soar upwards to brighter spheres
where we would be welcomed by the true values of life. How alluring is
the song of Sirens chanted by our physics with its high "C," the
velocity of light to the second power, which we have got to know as a
factor in this secret store of energy.
But these dreams are futile. For Einstein, to whom we owe this formula
so promising of wonders, not only denies that it can be applied
practically, but also brings forward another argument that casts us down
to earth again. Supposing, he explained, it were possible to set free
this enormous store of energy, then we should only arrive at an age,
compared with which the present coal age would have to be called golden.
And, unfortunately, we find ourselves obliged to fall in with this view,
which is based in the wise old saw μηδὲν ἄγαν, _ne quid
nimis_, nothing in excess. Applied to our case, this means that when
such a measure of power is set free, it does not serve a useful purpose,
but leads to destruction. The process of burning, which we used as an
illustration, calls up the picture of an oven in which we can imagine
this wholesale production of energy, and experience tells us that we
should not heat an oven with dynamite.
If technical developments of this kind were to come about, the energy
supply would probably not be capable of regulation at all. It makes no
difference if we say that we only want a part of those 20 billion
calories, and that we should be glad to be able to multiply the 8000
calories required to-day by 100. That is not possible, for if we should
succeed in disintegrating the atom, it seems that we should have the
billions of calories rushing unchecked on us, and we should find
ourselves unable to cope with them, nay, perhaps even the solid ground,
on which we move, could not withstand them.
No discovery remains a monopoly of only a few people. If a very careful
scientist should really succeed in producing a practical heating or
driving effect from the atom, then any untrained person would be able to
blow up a whole town by means of only a minute quantity of substance.
And any suicidal maniac who hated his fellows and wished to pulverize
all habitations within a wide range would only have to conceive the plan
to carry it out at a moment's notice. All the bombardments that have
taken place ever since fire-arms were invented would be mere child's
play compared with the destruction that could be caused by two buckets
of coal.
At intervals we see stars light up in the heavens, and then become
extinguished again; from these we infer that world catastrophes have
occurred. We do not know whether it is due to the explosion of hydrogen
with other gases, or to collisions between two stellar bodies. There is
still room for the assumption that, immeasurably far away in yonder
regions of celestial space, something is happening which a malevolent
inhabitant of our earth, who has discovered the secret of smashing the
atom, might here repeat. And even if our imaginations can be stretched
to paint the blessings of this release of energy, they certainly fail to
conjure up visions of the disastrous effects which would result.
Einstein turned to a page in a learned work of the mathematical
physicist Weyl of Zürich, and pointed out a part that dealt with such
an appalling liberation of energy. It seemed to me to be of the nature
of a fervent prayer that Heaven preserve us from such explosive forces
ever being let loose on mankind!
Subject to present impossibility, it is possible to weave many parallel
instances. It is conceivable that by some yet undiscovered process
alcohol may be prepared as plentifully and as cheaply as ordinary water.
This would end the shortage of alcohol, and would assure delirium
tremens for hundreds of thousands. The evil would far outweigh the good,
although it might be avoidable, for one can, even if with great
difficulty, imagine precautionary measures.
War technique might lead to the use of weapons of great range, which
would enable a small number of adventurers to conquer a Great Power. It
will be objected: this will hold vice versa, too. Nevertheless, this
would not alter the fact that such long-range weapons would probably
lead to the destruction of civilization. Our last hope of an escape
would be in a superior moral outlook of future generations, which the
optimist may imagine to himself as the _force majeure_.
There are apparently only two inventions, in themselves triumphs of
intellect, against which one would have no defence. The first would be
thought-reading made applicable to all, and with which Kant has dealt
under the term "thinking aloud." What is nowadays a rare and very
imperfect telepathic "turn" may yet be generalized and perfected in a
manner which Kant supposed not impossible on some distant planet. The
association and converse of man with his fellows would not stand the
test of this invention, and we should have to be angels to survive it
even for a day.
The second invention would be the solution of this _mc_^2-problem, which
I call a problem only because I fail to discover a proper term, whereas
so far was it from being a problem for Einstein that it was only in my
presence he began to reckon it out in figures from the symbolic formula.
To us average beings a Utopia may disclose itself, a short frenzy of joy
followed by a cold douche: Einstein stands above it as the pure
searcher, who is interested only in the scientific fact, and who, even
at the first knowledge of it, preserves its essentially theoretical
importance from attempts to apply it practically. If, then, another
wishes to hammer out into a fantastic gold-leaf what he has produced as
a little particle of gold in his physical investigations, he offers no
opposition to such thought-experiments, for one of the deepest traits of
his nature is tolerance.
A. Pflüger, one of the best qualified heralds of the new doctrine, has
touched on the above matter in his essay, _The Principle of Relativity_.
Einstein praised this pamphlet; I mentioned that the author took a view
different from that of Einstein, of the possibility of making accessible
the _mc_^2. In discussing the practical significance of this
eventuality, Pflüger says: "It will be time to talk of this point again
a hundred years hence." This seems a short time-limit, even if none of
us will live to be present at the discussion. Einstein smiled at this
pause of a hundred years, and merely repeated, "A very good essay!" It
is not for me to offer contradictions; and, as far as the implied
prognostication is concerned, it will be best for mankind if it should
prove to be false. If the optimum is unattainable, at least we shall be
spared the worst, which is what the realization of this prophecy would
inflict on us.
Some months after the above discussion had first been put to paper, the
world was confronted by a new scientific event. The English physicist
Rutherford had, with deliberate intention, actually succeeded in
splitting up the atom. When I questioned Einstein on the possible
consequences of this experimental achievement, he declared with his
usual frankness, one of the treasures of his character, that he had now
occasion to modify somewhat the opinion he had shortly before expressed.
This is not to mean that he now considered the practical goal of getting
unlimited supply of energy as having been brought within the realm of
possibility. He gave it as his view that we are now entering on a new
stage of development, which may perhaps disclose fresh openings for
technical science. The scientific importance of these new experiments
with the atom was certainly to be considered very great.
In Rutherford's operations the atom is treated as if he were dealing
with a fortress: he subjects it to a bombardment and then seeks to fire
into the breach. The fortress is still certainly far from capitulating,
but signs of disruption have become observable. A hail of bullets caused
holes, tears, and splinterings.
The projectiles hurled by Rutherford are alpha-particles shot out by
radium, and their velocity approaches two-thirds that of light. Owing to
the extreme violence of the impact, they succeeded in doing damage to
certain atoms enclosed in evacuated glass tubes. It was shown that atoms
of nitrogen had been disrupted. It is still unknown what quantities of
energy are released in this process. This splitting up of the atom
carried out with intention can, indeed, be detected only by the most
careful investigations.
As far as practical applications are concerned, then, we have got no
further, although we have renewed grounds for hope. The unit of measure,
as it were, is still out of proportion to the material to be cut. For
the forces which Rutherford had to use to attain this result are
relatively very considerable. He derived them from a gramme of radium,
which is able to liberate several milliard calories, whereas the net
practical result in Rutherford's experiment is still immeasurably small.
Nevertheless, it is scientifically established that it is possible to
split up atoms of one's own free will, and thus the fundamental
objection raised above falls to the ground.
There is also another reason for increased hope. It seems feasible that,
under certain conditions. Nature would automatically continue the
disruption of the atom, after a human being had intentionally started
it, as in the analogous case of a conflagration which extends, although
it may have started from a mere spark.
A by-product of future research might lead to the transmutation of lead
into gold. The possibility of this transformation of elements is subject
to the same arguments as those above about the splitting up of the atom
and the release of great quantities of energy. The path of decay from
radium to lead lies clearly exposed even now, but it is very
questionable whether mankind will finally have cause to offer up hymns
of thanksgiving if this line from lead on to the precious metals should
be continued, for it would cause our conception of the latter to be
shattered. Gold made from lead would not give rise to an increase in the
value of the meaner metal, but to the utter depreciation of gold, and
hence the loss of the standard of value that has been valid since the
beginning of our civilization. No economist would be possessed of a
sufficiently far-sighted vision to be able to measure the consequences
on the world's market of such a revolution in values.
The chief product would, of course, be the gain in energy, and we must
bear this in mind when we give ourselves up to our speculations, however
optimistic or catastrophic they may be. The impenetrable barrier
"impossible" no longer exists. Einstein's wonderful "Open Sesame," mass
times the square of the velocity of light, is thundering at the portals.
And mankind finds a new meaning in the old saw: One should never say
_never_!