I
THE TRUTH ABOUT THE HYDROGEN BOMB
I first heard about the hydrogen bomb in the spring of 1945 in Los
Alamos, New Mexico, where our scientists were putting the finishing
touches on the model-T uranium, or plutonium, fission bomb. I learned to
my astonishment that, in addition to this work, they were already
considering preliminary designs for a hydrogen-fusion bomb, which in
their lighter moments they called the “Superduper” or just the “Super.”
I can still remember my shock and incredulity when I first heard about
it from one of the scientists assigned to me by Dr. J. Robert
Oppenheimer as guides in the Dantesque world that was Los Alamos, where
the very atmosphere gave one the sense of being in the presence of the
supernatural. It seemed so fantastic to talk of a superatomic bomb even
before the uranium, or the plutonium, bomb had been completed and
tested—in fact, even before anybody knew that it would work at all—that
I was inclined at first to disbelieve it. Could anything be more
powerful, I found myself thinking, than a weapon that, on paper at
least, promised to release an explosive force of 20,000 tons of TNT? It
was a screwball world, this world of Los Alamos, I kept saying to
myself, and this was just a screwball notion of my younger scientific
mentors.
So at the first opportunity I put the question to Professor Hans A.
Bethe, of Cornell University, one of the world’s top atomic scientists,
who headed the elite circle of theoretical physicists at Los Alamos. Dr.
Bethe, I knew, was the outstanding authority in the world qualified to
talk about the subject, since he was the very man who first succeeded in
explaining how the fusion of hydrogen in the sun is the source of energy
that will make it possible for life to continue on earth for billions of
years.
“Is it true about the superbomb?” I asked him. “Will it really be as
much as fifty times as powerful as the uranium or plutonium bomb?”
I shall never forget the impact on me of his quiet answer as he looked
away toward the Sangre de Cristo (Blood of Christ) mountain range, their
peaks turning blood-red in the New Mexico twilight. “Yes,” he said, “it
could be made to equal a million tons of TNT.” Then, after a pause:
“Even more than a million.”
The tops of the mountains seemed to catch fire as he spoke.
Long before it was discovered that vast amounts of energy could be
liberated by the fission (splitting) of the nuclei of a twin of the
heaviest element in nature—namely, uranium of atomic mass 235 (235 times
the mass of the hydrogen atom, lightest of all the elements)—scientists
had known that truly staggering amounts of energy would be released if
one could fuse together four atoms of hydrogen, the first element on the
atomic table, into one atom of helium, element number two on that table,
which weighs about four times as much as hydrogen. In December
1938—three weeks before the discovery of uranium fission was announced
in Germany—Dr. Bethe had published his famous hypothesis about the
fusion of four hydrogen atoms in the sun to form helium. This provided
the first satisfactory explanation of the mechanism that enables the sun
to radiate away in space every second a quantity of light and heat
equivalent to the energy content of nearly fifteen quadrillion tons of
coal. And while Dr. Bethe was the first to work out the fine details of
the process, scientists had been speculating for more than twenty years
on the likelihood of hydrogen fusion in the sun as source of the sun’s
eternal radiance.
American audiences first heard about hydrogen as the solar fuel in a
lecture, on March 10, 1922, at the Franklin Institute, Philadelphia, by
Professor Francis William Aston, famous British Nobel-Prize-winning
chemist, who even at that early date warned mankind against what he
called “tinkering with the angry atoms.” His words on that occasion have
a strange prophetic ring, though most of what he said is now known to be
wrong. “Should the research worker of the future discover some means of
releasing this energy [from hydrogen] in a form which could be
employed,” he predicted, “the human race will have at its command powers
beyond the dreams of scientific fiction, but the remote possibility must
always be considered that the energy, once liberated, will be completely
uncontrollable and by its violence detonate a neighboring substance. If
this happens, all of the hydrogen on earth might be transformed [into
helium] at once, and this most successful experiment might be published
to the rest of the universe in the form of a new star of extraordinary
brilliance, as the earth blew up in one vast explosion.”
By 1945 we had learned that many things were wrong in Professor Aston’s
prophecy. It had been definitely established, for example, that it would
be impossible to “transform all the hydrogen on earth at once,” no
matter how many superduper hydrogen bombs were to be exploded. In fact,
we had learned that, under conditions as they exist on earth, we could
never use common hydrogen, the element that makes up one ninth by weight
of all water, either in a superduper bomb or as an atomic fuel for
power. On the other hand, ten years after Dr. Aston’s lecture a new type
of hydrogen was discovered to exist in nature. It was found to
constitute one five-thousandth part of the earth’s waters, including the
water in the tissues of plants and animals. It was shown to have an
atomic weight of two—double the weight of common hydrogen—and was named
deuterium. The nucleus, or center, of the deuterium atom was named the
deuteron, to distinguish it from the nucleus of common hydrogen, known
as the proton. Deuterium also became popularly known as “heavy
hydrogen.” Water containing two deuterium atoms in place of the two
atoms of light hydrogen became known as “heavy water.”
The most startling fact learned about deuterium soon after its discovery
in 1932 was that it offered potentialities as an atomic fuel, or an
explosive, of tremendous energy, provided one condition could be met.
This condition was a “match” to light it with. And here was the catch.
The flame of this match, it was found, would have to have a temperature
of the order of 50,000,000 degrees centigrade, two and a half times the
temperature in the interior of the sun.
Oddly enough, the discovery of the principle that made the atomic bomb
possible also brought with it the promise that a “deuterium fire” might,
after all, be lighted on earth. Early studies had revealed that the
explosion of an atomic bomb, if it lived up to expectations, would
generate a central temperature of about 50,000,000 degrees centigrade.
Here, at last, was the promise of realization of the impossible—the
50,000,000 degree match.
The men of Los Alamos thus knew that if the atomic bomb they were just
completing for its first test worked as they hoped it would, it could be
used as the match to light the deuterium fire. They could build a
superduper bomb of a thousand times the power of the atomic bomb by
incorporating deuterium in the A-bomb, the explosion of which would act
as the trigger for the superexplosion. And they also knew that the
deuterium bomb held such additional potentialities of terror, beyond its
vastly greater blasting and burning power, that the step from the duper
to the super would be just as great as the step from TNT to the duper.
The hydrogen bomb, H-bomb, or hell bomb, as the fusion bomb had become
popularly known, thus became a reality in the flash of the explosion of
the first atomic bomb at 5:30 of the morning of July 16, 1945, on the
New Mexico desert. As the men of Los Alamos, of whom I was at that time
a privileged member, watched the supramundane light and the apocalyptic
mushroom-topped mountain of nuclear fire rising to a height of more than
eight miles through the clouds, they did not have to wait until they
checked with their measuring instruments to know that a match sparking a
flame of about 50,000,000 degrees centigrade had been lighted on earth
for the first time. The size of the fire mountain and the
end-of-the-world-like thunder that reverberated all around, told the
tale better than any puny man-made instruments.
And there in our midst, as we learned only recently, stood a Judas,
Klaus Fuchs, a name that “will live in infamy” along with that of other
archtraitors of history. By the greatest of ironies, there he was, this
spy, standing right in the center of what we believed at the time to be
the world’s greatest secret, waiting at that very moment to tell the
Russians of our success and how we achieved it. As he confessed five
years later, he betrayed to them the most intimate details not only
about the A-bomb but about the H-bomb as well—details that he learned as
a member of the innermost of inner circles. For, alas, he was a trusted
member of the theoretical division, the sanctum sanctorum of Los Alamos.
This select group of scientists, behind doubly and triply locked doors,
discussed in whispers their ideas about the superduper.
His associates at Los Alamos, who should know, sadly admit that Fuchs
made it possible for Russia to develop her A-bomb at least a year ahead
of time. It is my own conviction that the information he gave the
Russians made it possible for their scientists to attain their goal at
least three, and possibly as much as ten, years sooner than they could
have done it on their own. Yet, though Fuchs confessed everything he
told the Russians, the content of his confession is still kept a top
secret from the American people, who sadly need information on one of
the greatest problems facing mankind. The reason given is that we cannot
actually be sure that Fuchs told the Russians all that he says he did,
and, if published, his confession might, by his tricky design, give the
Russians additional information. Of course, anything is possible for a
warped mind such as that of Fuchs. Nevertheless, it seems highly
implausible that this traitor, who went to the Russians voluntarily,
should withhold any vital information from them for as long as five
years. The best evidence that he didn’t is the Russian A-bomb.
Yet some good comes even of the greatest evil. All the circumstantial
evidence points to the fact that during the five-year period following
the end of the war our work on the hydrogen bomb had stopped completely.
The A-bomb was the mightiest weapon in the world, we seem to have
reasoned, and it would take Russia many years before she would get an
A-bomb of her own. Why spend great efforts on a superbomb?
The shock when Russia exploded her first A-bomb much sooner than we
expected, topped by the second shock that Fuchs had handed Moscow all
our major secrets on a platter—including, as must be surmised, those of
the H-bomb—awakened us to the facts of life. It is no accident that
President Truman’s official announcement of the order to build “the
so-called hydrogen bomb or superbomb” came within three days of the
announcement of Fuchs’s arrest and confession. The President gave his
order with full knowledge of Fuchs’s confession, which made it evident
that the Russians were already at work on the hydrogen bomb and had
probably been working on it uninterruptedly since 1945. The tragic
prospect is that instead of the Russians catching up with us, it is we
who may have to catch up with them.
Five years after the first announcement of the explosion of the A-bomb
over Hiroshima, even the most intelligent Americans still have only the
vaguest idea about the facts. Yet these facts are within the
understanding of the average man. If we keep the earlier analogy of the
match in mind, it becomes simple to understand the principles underlying
both the A-bomb, now more correctly identified as the “fission bomb,”
and the hydrogen bomb, more properly described as the “fusion bomb.”
Our principal fuel is coal, which, as everyone knows, is “bottled
sunshine,” stored up in plants that grew about two hundred million years
ago. When we apply the small amount of heat energy from a match, the
bottled energy is released in the form of light and heat, which we can
use in a great variety of ways. The point here is that it requires only
the application of a very small amount of energy from a match to release
a very large amount of energy that has been stored for millions of years
in the ancient plants we know as coal.
Now, during the past half century we discovered that the nuclei, or
centers, of the smallest units of which the ninety-odd elements of the
material universe are made up—units we know as atoms—had stored up
within them since the beginning of creation amounts of energy millions
of times greater than is stored up by the sun in coal. But we had no
match with which to start an atomic fire burning.
Then, in January 1939, came the world-shaking discovery of the
phenomenon known as uranium fission. In simple language, we had found a
proper “match” for lighting a fire with a twin of uranium, the
ninety-second, and last, natural element. This twin is a rare form of
uranium known as uranium 235—the figure signifying that it is 235 times
heavier than common hydrogen. Doubly phenomenal, the discovery of
uranium fission meant that to light the atomic fire, with the release of
stored-up energy three million times greater than that of coal and
twenty million times that of TNT (on an equal-weight basis) would
require no match at all. When proper conditions are met, the atomic fire
would be lighted automatically by spontaneous combustion.
What are these proper conditions? In the presence of certain chemical
agencies, spontaneous combustion will take place when an easily burning
substance, such as sawdust, for example, accumulates heat until it
reaches the kindling temperature at which it ignites. The chemical
agencies here are the equivalent of a match.
The requirement to start the spontaneous combustion of uranium 235, and
also of two man-made elements named plutonium and uranium 233 (all three
known as fissionable materials or nuclear fuels), is just as simple. In
this operation you do not need a critical temperature, but what is known
as a critical mass. This simply means that spontaneous combustion of any
one of the three atomic fuels takes place as soon as you assemble a lump
of a certain weight. The actual critical mass is a top secret. But the
noted British physicist, Dr. M. L. E. Oliphant, of radar fame, published
in 1946 his own estimate, which places its weight between ten and thirty
kilograms. If so, this would mean that a lump of uranium 235 (U-235),
plutonium, or U-233, weighing ten or thirty kilograms, as the case may
be, would explode automatically by spontaneous combustion and release an
explosive force of 20,000 tons of TNT for each kilogram undergoing
complete combustion. In the conventional A-bomb a critical mass is
assembled in the last split second by a timing mechanism that brings
together, let us say, one tenth and nine tenths of a critical mass. The
spontaneous combustion that followed such a consummation on August 6 and
9, 1945 destroyed Hiroshima and Nagasaki.
Thus, if we substitute the familiar phrase “spontaneous combustion” for
the less familiar word “fission,” we get a clear understanding of what
is known in scientific jargon as the “fission process,” a
“self-multiplying chain reaction with neutrons,” and similar technical
mumbo-jumbo. These terms simply mean the lighting of an atomic fire and
the release of great amounts of the energy stored in the nuclei of U-235
since the beginning of the universe. The two so-called man-made elements
are not really created. They are merely transformed out of two natural
heavy elements in such a way that their stored energy is liberated by
the process of spontaneous combustion.
Why, one may ask, does not spontaneous combustion of U-235 take place in
nature? Why, indeed, has not all the U-235 in nature caught fire
automatically long ago? To this also there is a simple answer. Just as
in the spontaneous combustion of sawdust the material must be dry enough
to burn, so must the U-235. Only in place of the word “dry” we must use
the word “concentrated.” The U-235 found in nature is very much diluted
with another element that makes it “wet.” It therefore must be separated
first, by a very laborious and costly process, from the nonfissionable,
or “wetting,” element. Even then it won’t catch fire, and could not be
made to burn by any means, until the amount separated (“dried”) reaches
the critical mass. When these two conditions—conditions that do not
exist in nature—are met, the U-235 catches fire just as sawdust does
when it reaches the critical temperature.
The fact that as soon as a critical mass is assembled the three
elemental atomic fuels burst into flame automatically thus puts a
definite limit to the amount of material that can be used in the
conventional A-bomb. The best you can do is to incorporate into a bomb
two fragments, let us say, of nine tenths of a critical mass each. To
enclose more than two such fragments would present difficulties that
appear impossible to overcome. It is this limitation of size, an
insurmountable roadblock put there by mother nature, that makes the
basic difference between the A-bomb and the H-bomb.
For, as we have already seen, to light an atomic fire with deuterium it
is necessary to strike a match generating a flame with a temperature of
about 50,000,000 degrees centigrade. As long as no such match is
applied, no fire can start. It thus becomes obvious that deuterium is
not limited by nature to a critical mass. A quantity of deuterium a
thousand times the amount of the U-235, and hence a thousand times more
powerful, can therefore be incorporated in an ordinary A-bomb, where it
would remain quiescent until the A-bomb match is struck. Weight for
weight, deuterium has only a little more energy content than U-235, so
that a bomb incorporating a 1,000 kilograms (one ton) of deuterium would
thus have an energy of 20,000,000 tons of TNT.
Here must be mentioned another form of hydrogen, named tritium. It has
long ago disappeared from nature but it is now being re-created in
ponderable amounts in our atomic furnaces. Tritium, the nucleus of which
is known as a triton, weighs three times as much as the lightest form of
hydrogen. It has an energy content nearly twice that of deuterium. But
it is very difficult to make and is extremely expensive. Its cost per
kilogram at present AEC prices is close to a billion dollars, as
compared with no more than $4,500 for a kilogram of deuterium. A
combination of deuterons and tritons would release the greatest energy
of all, 3.5 times the energy of deuterons alone. It would reduce the
amount of tritons required to half the volume and three fifths of the
weight required in a pure triton bomb, thus making the cost considerably
lower.
But why bother with such fantastically costly tritons when we can get
all the deuterium we want at no more than $4,500 a kilogram, while we
can make up the difference in energy by merely incorporating two to
three and a half times as much deuterium? Here we are dealing with what
is probably the most ticklish question in the design of the H-bomb.
To light a fire successfully, it is not enough merely to have a match.
The match must burn for a time long enough for its flame to act. If you
try to light a cigarette in a strong wind, the wind may blow out your
match so fast that your cigarette will not light. The same question
presents itself here, but on a much greater scale. The match for
lighting deuterium—namely, the A-bomb—burns only for about a hundred
billionths of a second. Is this time long enough to light the
“cigarette” with this one and only “match”?
It is known that the time is much too slow for lighting deuterium in its
gaseous form. But it is also known that the inflammability is much
faster when the gas is compressed to its liquid form, at which its
density is 790 times greater. At this density it would take only seven
liters (about 7.4 quarts) per one kilogram (2.2 pounds), as compared
with 5,555 liters for gaseous deuterium. And it catches fire in a much
shorter time.
Is this time long enough? On the answer to this question will depend
whether the hydrogen bomb will consist of deuterium alone or of
deuterium and tritium, for it is known that the deuteron-triton
combination catches fire much faster than deuterons or tritons alone.
We were already working with tritium in Los Alamos as far back as 1945.
I remember the time when Dr. Oppenheimer, wartime scientific director of
Los Alamos, went to a large safe and brought out a small vial of a clear
liquid that looked like water. It was the first highly diluted minute
sample of superheavy water, composed of tritium and oxygen, ever to
exist in the world, or anywhere in the universe, for that matter. We
both looked at it in silent, rapt admiration. Though we did not speak,
each of us knew what the other was thinking. Here was something, our
thoughts ran, that existed on earth in gaseous form some two billion
years ago, long before there were any waters or any forms of life. Here
was something with the power to return the earth to its lifeless state
of two billion years ago.
The question of what type of hydrogen is to be used in the H-bomb
therefore hangs on the question of which one of the possible
combinations will catch fire by the light of a match that is blown out
after an interval of about a hundred billionths of a second. On the
answer to this question will also depend the time it will take us to
complete the H-bomb and its cost. To make a bomb of a thousand times the
power of the A-bomb would require a 1,000 kilograms of deuterium at a
cost of $4,500,000, or 171 kilograms of tritium and 114 kilograms of
deuterium at a total cost of more than $166,000,000,000 at current
prices, not counting the cost of the A-bomb trigger. Large-scale
production of tritium, however, will most certainly reduce its cost
enormously, possibly by a factor of ten thousand or more, while, as will
be indicated later, the amount of tritium, if required, may turn out to
be much smaller.
[Illustration: MAP BY DANIEL BROWNSTEIN]
We can thus see that if deuterium alone is found to be all that is
required to set off an H-bomb it will be cheap and relatively easy to
make in a short time—both for us and for Russia. Furthermore, such a
deuterium bomb would be practically limitless in size. One of a million
times the power of the Hiroshima bomb is possible, since deuterium can
be extracted in limitless amounts from plain water. On the other hand,
if sizable amounts of tritium are found necessary, the cost will be much
higher and it will take a considerably longer time, since the production
of tritium is very slow and costly. This, in turn, will place a definite
limit on the power of the H-bomb, since, unlike deuterium, the amounts
of tritium will necessarily always be limited. As will be shown later,
we are at present in a much more advantageous position to produce
tritium than is Russia, so that if tritium is found necessary, we have a
head start on her in H-bomb development.
The radius of destructiveness by the blast of a bomb with a thousand
times the energy of the A-bomb will be only ten times greater, since the
increase goes by the cube root of the energy. The radius of total
destruction by blast in Hiroshima was one mile. Therefore the radius of
a superbomb a thousand times more powerful will be ten miles, or a total
area of 314 square miles. A bomb a million times the power of the
Hiroshima bomb would require 1,000 tons of deuterium. Such a
super-superduper could be exploded at a distance from an abandoned,
innocent-looking tramp ship. It would have a radius of destruction by
blast of 100 miles and a destructive area of more than 30,000 square
miles. The time may come when we shall have to search every vessel
several hundred miles off shore. And the time may be nearer than we
think.
The radius over which the tremendous heat generated by a bomb of a
thousandfold the energy would produce fatal burns would be as far as
twenty miles from the center of the explosion. This radius increases as
the square root, instead of the cube root, of the power. The Hiroshima
bomb caused fatal burns at a radius of two thirds of a mile.
The effects of the radiations from a hydrogen bomb are so terrifying
that by describing them I run the risk of being branded a fearmonger.
Yet facts are facts, and they have been known to scientists for a long
time. It would be a disservice to the people if the facts were further
denied to them. We have already paid too high a price for a secrecy that
now turns out never to have been secret at all.
I can do no better than quote Albert Einstein. “The hydrogen bomb,” he
said, “appears on the public horizon as a probably attainable goal....
If successful, radioactive poisoning of the atmosphere, and hence
annihilation of any life on earth, has been brought within the range of
technical possibilities.”
What Dr. Einstein meant by “radioactive poisoning of the atmosphere, and
hence the annihilation of any life on earth,” was explained in realistic
detail by such eminent physicists as Dr. Bethe, Dr. Leo Szilard, Dr.
Edward Teller, and others. All of them may even now be engaged on work
on the hydrogen bomb.
Here is how “poisoning of the atmosphere” may result from the explosion
of a hydrogen bomb: Tremendous quantities of neutrons, which can enter
any substance in nature and make it radioactive, are liberated. In the
case of a deuterium bomb, one eighth of the mass used—125 grams per
kilogram—is liberated. In the case of a deuteron-tritium bomb, fully one
fifth of the mass—200 grams per kilogram—is released, while in a bomb
using pure tritium, fully one third of the mass—333 grams per
kilogram—is liberated as free neutrons. There are 600,000 billion
billion neutrons in each gram, each capable of producing a radioactive
atom in its environment. The neutron is one of the two building blocks
of the nuclei of all atoms.
These neutrons can be used to make any element radioactive, Professor
Szilard and his colleagues point out. It follows that the casing of the
bomb could be selected with a view to producing, after the neutrons
enter it, an especially powerful radioactive substance. Since each
artificially made, radioactive element gives out a specific type of
radiation and has a definite life span, after which it decays to one
half of its radioactivity, the designer of the bomb could rig it in such
a way that its explosion would spread into the air a tremendous cloud of
specially selected radioactive substances that would give off lethal
radiations for a definite period of time. In such a way a large area
could be made unfit for human or animal habitation for a definite period
of time, months or years.
Take, for example, the very common element cobalt. When bombarded with
neutrons, it turns into an intensely radioactive element, 320 times more
powerful than radium. Any given quantity of neutrons would produce sixty
times its weight in radioactive cobalt. If the bomb contains a ton of
deuterium, 250 pounds would come out as neutrons. On the assumption that
every neutron enters a cobalt atom, this would produce 7.5 tons of
radioactive cobalt. That quantity would give out as much radioactivity
as 2,400 tons of radium.
Now, this radioactive cobalt has a half-life of five years, meaning that
it loses half of its radioactive power at every five-year period. So
after a lapse of that period of time its radioactivity would be equal to
1,200 tons of radium, in ten years to 600 tons, and so on. If used as a
bomb-casing it would be pulverized and converted into a gigantic
radioactive cloud that would kill everything in the area it blankets.
Nor would it be confined to a particular area, since the winds would
take it thousands of miles, carrying death to distant places.
The radioactivity produced by the Bikini bombs was detected within one
week in the United States. In that short time the westerly winds swept
the radioactive air mass from Bikini, 4,150 miles away, to San
Francisco. When it reached our shores, the activity was weak and
completely harmless, but it was still detectable. That, by the way, was
how we learned that the Russians had exploded their first atomic bomb.
But, in the words of Professor Teller, one of the Los Alamos men who
made the preliminary studies on the hydrogen bomb, “if the activity
liberated at Bikini were multiplied by a factor of a hundred thousand or
a million, and if it were to be released off our Pacific Coast, the
whole of the United States would be endangered.” He added that “if such
a quantity of radioactivity should become available, an enemy could make
life hard or even impossible for us without delivering a single bomb
into our territory.”
One limitation to such an attack, Professor Teller points out, is the
boomerang effect of these gases on the attacker himself. The radioactive
gases would eventually drift over his own country, too. He adds,
however, that since these gases have different rates of decay—some
faster, some slower—the attacker is in a position to choose those
radioactive products best suited to his attack. “With the proper choice
he could ensure that his victim would be seriously damaged by them, and
that they would have decayed by the time they reached his own country.”
“It is not even impossible to imagine,” in the words of Professor
Teller, “that the effects of an atomic war fought with greatly perfected
weapons and pushed by utmost determination will endanger the survival of
man.... This specific possibility of destruction may help us realize
more clearly the probable consequences of an atomic war for our
civilization and the possible consequences for the whole human race.”
On this point Professor Szilard is much more specific. “Let us assume,”
he said at a University of Chicago Round Table, “that we make a
radioactive element which will live for five years and that we just let
it go into the air. During the following years it will gradually settle
out and cover the whole earth with dust. I have asked myself, ‘How many
neutrons or how much heavy hydrogen do we have to detonate to kill
everybody on earth by this particular method?’ I come up with about
fifty tons of neutrons as being plenty to kill everybody, which means
about 400 tons of heavy hydrogen” (deuterium).
Now, obviously Professor Szilard was stating the extreme case. He merely
called attention to the scientific fact that man now has at his
disposal, or soon will have, means that not only could wipe out all life
on earth, but could also make the earth itself unfit for life for many
generations to come, if not forever. Here we have indeed what is
probably the greatest example of irony in man’s history. The very
process in the sun that made life possible on earth, and is responsible
for its being maintained here, can now be used by man to wipe out that
very life and to ruin the earth for good.
It is inconceivable that any leaders of men today, or in the near
future, would resort to such an extreme measure. But the fact remains
that such a measure is possible. And it is by no means unthinkable that
a Hitler, faced with certain defeat, would not choose to die in a great
Götterdämmerung in which he would pull down the whole of humanity with
him to destruction. And who can be bold enough to guarantee that another
Hitler might not arise sometime, somewhere, possibly in a rejuvenated
Germany making another bid for world domination or total annihilation?
It is more likely, of course, that an attacker, particularly if he is
otherwise faced with certain defeat, might choose the less drastic
method outlined by Professor Teller, selecting for his weapon a
short-lived radioactive element that would have spent itself by the time
it reached his shores. If he is the sole possessor of the hydrogen bomb,
he may not even have to use it, a threat of its use being sufficient to
end the war on terms to his liking. In the face of such a threat, as
Professor Szilard pointed out, who would dare take the responsibility of
refusing?
These are the stark, unvarnished facts about the “so-called hydrogen
bomb.” They raise many questions to which the American people as a whole
will have to find the answer. It is possible, and the odds here are more
than even, that the very possession of the hydrogen bomb by both
ourselves and Russia will make war unthinkable, since neither side could
be the winner. This would be a near certainty if we had the answer to
Russia’s Trojan Horse method of taking over nations by first taking over
their governments, as was done in Poland, Czechoslovakia, Hungary, and
the Balkan countries. Suppose the Communists take over Italy, then
Germany, by the same method. What would we do then? The answer is, of
course, that if we wait until “then,” everything would be lost, no
matter what we did. It therefore becomes obvious that our very existence
may depend on what we do _here_ and _now_ to prevent such an
eventuality.
Now that the hydrogen bomb has come out into the open after five years
as a super-top secret, the authorities, and particularly the Atomic
Energy Commission, may be called upon to answer some embarrassing
questions. “Why,” we may ask, “was the work on the hydrogen bomb
apparently dropped altogether during the past five years?” According to
Professor Bethe, it would take about three years to develop it. This
means that, had we continued working on it in 1945 and thereafter, we
would have had it as far back as 1948. We have thus lost five precious
years, our loss being Russia’s gain.
Some scientists and others contend that, because of our great harbor and
industrial cities, the hydrogen bomb would be a greater threat to us
than to the Soviet, because most Russian cities are much smaller than
ours, while her industries are much more dispersed. There may be some
truth in this. But on the other hand there are some great advantages on
our side. With a strong Navy and good submarine-detecting devices we may
have control of the seas and be able to prevent the delivery of the
hydrogen bomb by ship or submarine. With a strong Air Force and radar
system we could prevent the delivery of hydrogen bombs from the air.
By far the most important advantage the possession of the hydrogen bomb
would give us against Russia is its possible use as a tactical weapon
against huge land armies. Since they can devastate such large areas, one
or two hydrogen bombs, depending on their size, could wipe out entire
armies on the march, even before they succeeded in crossing the border
of an intended victim. The H-bomb would thus counterbalance, if not
completely nullify, the one great advantage Russia possesses—huge land
armies capable of overrunning western Europe. The bomb might thus serve
as the final deterrent to any temptation the Kremlin’s rulers may have
to invade the Atlantic Pact countries.
Yet no matter how one looks at it, the advent of the H-bomb constitutes
the greatest threat to the survival of the human race since the Black
Death.
One is reminded of a dinner conversation in Paris in 1869, recorded in
the _Journal_ of the Goncourt brothers. Some of the famous savants of
the day were crystal-gazing into the scientific future a hundred years
away. The great chemist Pierre Berthelot predicted that by 1969 “man
would know of what the atom is constituted and would be able, at will,
to moderate, extinguish, and light up the sun as if it were a gas lamp.”
(This prophecy has almost come true.) Claude Bernard, the greatest
physiologist of the day, saw a future in which “man would be so
completely the master of organic law that he would create life
[artificially] in competition with God.”
To which the Goncourt brothers added the postscript: “To all of this we
raised no objection. But we have the feeling that when this time comes
to science, God with His white beard will come down to earth, swinging a
bunch of keys, and will say to humanity, the way they say at five
o’clock at the salon: ‘Closing time, gentlemen!’”
II
THE REAL SECRET OF THE HYDROGEN BOMB
Can the hydrogen bomb actually be made? If so, how soon? How much will
it cost in money and vital materials? Above all, will it, if made, add
enough to our security to make the effort worth while?
As was pointed out by Prof. Robert F. Bacher of the California Institute
of Technology, one of the chief architects of the wartime atomic bomb
and the first scientific member of the Atomic Energy Commission, “since
the President has directed the AEC to continue with the development [‘of
the so-called hydrogen, or super bomb’] we can assume that this
development is regarded as both possible and feasible.” Many eminent
physicists believe that it can be made, and the use by the President of
the word “continue” suggests that this belief is based on more than
theory. No less an authority than Albert Einstein has stated publicly
that he regards the H-bomb as “a probably attainable goal.”
On the other hand, there are scientists of high eminence, such as Dr.
Robert A. Millikan, our oldest living Nobel-Prize-winner in physics, who
doubt whether the H-bomb can be made at all. And there are also those
who express the view that, while it probably could be made, it would not
offer advantages great enough, if any, to justify the cost in vital
strategic materials necessary for our security.
Fortunately, facts mostly buried in technical literature make it
possible for us to go behind the scientific curtain and look intimately
at the reasons for these differences in opinion. More important still,
these facts not only provide us with a clearer picture of the nature of
the problem but also enable us to make some reasonable deductions or
speculations. The scientists directly involved do not feel free to
discuss these matters openly, not because they would be violating
security, but because of the jittery atmosphere that acts as a damper on
open discussion even of subjects known to be non-secret.
We already know that the so-called hydrogen bomb, if it is to be made at
all, cannot be made of the abundant common hydrogen of atomic mass one,
and that there are only two possible materials that could be used for
such a purpose: deuterium, a hydrogen twin twice the weight of common
hydrogen, which constitutes two hundredths of one per cent of the
hydrogen in all waters; and a man-made variety of hydrogen, three times
the weight of the lightest variety, known as tritium. We also know that
to explode either deuterium or tritium (also known, respectively, as
heavy and superheavy hydrogen) a temperature measured in millions of
degrees is required. This is attainable on earth only in the explosion
of an A-bomb, and therefore the A-bomb would have to serve as the fuse
to set off an explosion of deuterium, tritium, or a mixture of the two.
These facts, fundamental as they are, merely give us a general idea of
the conditions required to make the H-bomb. All concerned, including Dr.
Millikan, fully accept the validity of these facts. But there is one
other factor at the very heart of the problem—the extremely short time
at our disposal in which to kindle the hydrogen bomb with the A-bomb
match. According to statements attributed to him in the press, Dr.
Millikan believes that the time is too short; in other words, he seems
to be convinced that the A-bomb match will be blown out before we have
time to light the fire. Those of opposite view believe that methods can
be devised for “shielding the match against the wind” for just long
enough to light the fire. As we shall presently see, it is these methods
for shielding the match that lead some to doubt whether the game would
be worth the candle, or the match, if you will. These honest doubts are
based on the possibility that, even if successful, the shielding might
exact too high a price in terms of vital materials, particularly the
stuff out of which A-bombs are made—plutonium. According to this view,
we may at best be getting but a very small return for our investment in
materials vitally important in war as well as in peace. Even though the
price in dollars were to be brought down to a negligible amount.
A closer look at the details of the problem may enable us to penetrate
the thick fog that now envelops the subject. We may begin with a
quotation from Dr. Bacher, who outlined the principle involved with
remarkable clarity. “The real problem in developing and constructing a
hydrogen bomb,” he said in a notable address before the Los Angeles Town
Hall,
is, “How do you get it going?” The heavy hydrogens, deuterium and
tritium, are suitable substances if somehow they could be heated hot
enough and kept hot. This problem is a little bit like the job of
making a fire at 20 degrees below zero in the mountains with green
wood which is covered with ice and with very little kindling. Today,
scientists tell us that such a fire can probably be kindled.
Once you get the fire going, of course, you can pile on the wood and
make a very sizeable conflagration. In the same way with the hydrogen
bomb, more heavy hydrogen can be used and a bigger explosion obtained.
It has been called an open-ended weapon, meaning that more materials
can be added and a bigger explosion obtained.
The phrase that goes to the very heart of the problem is “very little
kindling,” which is another way of illustrating the difficulty of
lighting a fire in a high wind when you have only one match. We know
that to ignite deuterium, by far the cheaper and more abundant of the
two H-bomb elements, a temperature comparable to those existing in the
interior of the sun, some 20,000,000 degrees centigrade, is necessary.
This temperature can be realized on earth only in the explosion of an
A-bomb. We also know that the wartime model A-bombs generated a
temperature of about 50,000,000 degrees, more than enough to light a
deuterium fire. The trouble lies in the extremely short time interval,
of the order of a millionth of a second (microsecond), and a fraction
thereof, during which the A-bomb is held together before it flies apart.
In the words of Professor Bacher, we must make our green, ice-covered
wood catch fire in the subzero mountain weather before the “very little
kindling” we have is burned up.
The times at which deuterium will ignite at any given temperature, in
both its gaseous and its liquid form, are widely known among nuclear
scientists everywhere, including Russia, through publication in official
scientific literature of a well-known formula, originally worked out by
two European scientists as far back as 1929, and more recently improved
upon by Professor George Gamow and Professor Teller. By this formula,
derived from actual experiments, it is known that deuterium in its
gaseous form will require as long as 128 seconds to ignite at a
temperature of 50,000,000 degrees centigrade, well above 100,000,000
times longer than the time in which our little kindling is used up. This
obviously rules out deuterium in its natural gaseous form as material
for an H-bomb.
How about liquid deuterium? We know that the more atoms there are per
unit volume (namely, the greater the density), the faster is the time of
the reaction. The increase in the speed of the reaction (in this case
the ignition of the deuterium) is directly proportional to the square of
the density. For example, if the density, (that is, the number of atoms
per unit volume) is increased by a factor of 10, the time of ignition
will be speeded up by the square of 10, or 100 times faster. Since
liquid deuterium has a density nearly 800 times that of gaseous
deuterium, this means that liquid deuterium (which must be maintained at
a temperature of 423 degrees below zero Fahrenheit at a pressure above
one atmosphere) would ignite 640,000 times faster (namely, in
1/640,000th part of the time) than its gaseous form. Arithmetic shows
that the ignition time for liquid deuterium at 50,000,000 degrees
centigrade will be 200 microseconds, still 200 times longer than the
period in which our kindling is consumed.
The same formula also reveals the time it would take liquid deuterium to
ignite at higher temperatures, the increase of which shortens the
ignition time. These figures show that the ignition time for liquid
deuterium at 75,000,000 degrees centigrade is 40 microseconds. At
100,000,000 degrees the time is 30 microseconds; at 150,000,000 degrees,
15 microseconds; and at 200,000,000 degrees on the centigrade scale,
about 4.8 millionths of a second. Doubling the temperature speeds up the
ignition time for liquid deuterium by a factor of about six.
The problem thus is a dual one: to raise the temperature at which the
A-bomb explodes, and to extend the time before the A-bomb flies apart.
It is also obvious that if the liquid deuterium is to be ignited at all,
it must be done before the bomb has disintegrated—that is, during the
incredibly short time interval before it expands into a cloud of vapor
and gas, since by then the deuterium would no longer be liquid.
Can we increase the A-bomb’s temperature fourfold to 200,000,000 degrees
and literally make time stand still while it holds together for nearly
five millionths of a second? To get a better understanding of the
problem we must take a closer look at what takes place inside the A-bomb
during the infinitesimal interval in which it comes to life.
This life history of the A-bomb is an incredible tale, from the time its
inner mechanisms are set in motion until its metamorphosis into a great
ball of fire. As explained earlier, the A-bomb’s explosion takes place
through a process akin to spontaneous combustion as soon as a certain
minimum amount (critical mass) of either one of two fissionable
(combustible) elements—uranium 235 or plutonium—is assembled in one
unit. The most obvious way it takes place is by bringing together two
pieces of uranium 235 (U-235), or plutonium, each less than a critical
mass, firing one of these into the other with a gun mechanism, thus
creating a critical mass at the last minute. If, for example, the
critical mass at which spontaneous combustion takes place is ten
kilograms (the actual figure is a top secret), then the firing of a
piece of one kilogram into another of nine kilograms would bring
together a critical mass that would explode faster than the eye could
wink—in fact, some thousands of times faster than TNT.
Just as an ordinary fire needs oxygen, so does an atomic fire require
the tremendously powerful atomic particles known as neutrons. Unlike
oxygen, however, neutrons do not exist in a free state in nature. Their
habitat is the nuclei, or hearts, of the atoms. How, then, does the
spontaneous combustion of the critical mass of U-235 or plutonium begin?
All we need is a single neutron to start things going, and this one
neutron may be supplied in one of several ways. It can come from the
nucleus of an atom in the atmosphere, or inside the bomb, shattered by a
powerful cosmic ray that comes from outside the earth. Or the emanation
from some radioactive element in the atmosphere, or from one introduced
into the body of the bomb, may split the first U-235 or plutonium atom,
knock out two neutrons, and thus start a chain reaction of
self-multiplying neutrons.
To understand the chain reaction requires only a little arithmetic. The
first atom split releases, on the average, two neutrons, which split two
atoms, which release four neutrons, which split four atoms, which
release eight neutrons, and so on, in a geometric progression that, as
can be seen, doubles itself at each successive step. Arithmetic shows
that anything that is multiplied by two at every step will reach a 1,000
(in round numbers) in the first ten steps, and will multiply itself by a
1,000 at every ten steps thereafter, reaching a million in twenty steps,
a billion in thirty, a trillion in forty, and so on. It can thus be seen
that after seventy generations of self-multiplying neutrons the
astronomical figure of two billion trillion (2 followed by 21 zeros)
atoms have been split.
At this point let us hold our breath and get set to believe what at
first glance may appear to be unbelievable. The time it takes to split
these two billion trillion atoms is no more than one millionth of a
second (one microsecond). If we keep this time element in mind we can
arrive at a clear understanding of the tremendous problem involved in
exploding an A- or an H-bomb.
And while we are recovering from the first shock we may as well get set
for another. That unimaginable figure of two billion trillion atoms
represents the splitting (explosion) of no more than one gram (1/28th of
an ounce) of U-235, or plutonium.
Now, the energy released in the splitting of one gram of U-235 is
equivalent in power to the explosive force of 20 tons of TNT, or two
old-fashioned blockbusters. Since we know from President Truman’s
announcement following the bombing of Hiroshima that the wartime A-bomb
“had more power than 20,000 tons of TNT,” it means that the atoms in an
entire kilogram (1,000 grams) of U-235 or plutonium must have been
split. In other words, after the A-bomb had reached a power of 20 tons
of TNT, it had to be kept together long enough to increase its power a
thousandfold to 20,000 tons. This, as we have seen, requires only ten
more steps. It can also be seen that it is these ten final crucial steps
that make all the difference between a bomb equal to only two
blockbusters, which would have been a most miserable two-billion-dollar
fiasco, and an atomic bomb equal in power to two thousand blockbusters.
With the aid of these facts we are at last in a position to grasp the
enormousness of the problem that confronted our A-bomb designers at Los
Alamos and is confronting them again today. It can be seen that for a
bomb to multiply itself from 20 to 20,000 tons in ten steps by doubling
its power at every step, it has to pass successively the stages of 40,
80, 160, 320, and so on, until it reaches an explosive power of 2,500
tons at the seventh step. Yet it still has to be held together for three
more steps, during which it reaches the enormous power of 5,000 and
10,000 tons of TNT, without exploding.
Here was an irresistible force, and the problem was to surround it with
an immovable body, or at least a body that would remain immovable long
enough for the chain reaction to take just ten additional steps
following the first seventy. There is only one fact of nature that makes
this possible, or even thinkable—the last ten steps from 20 to 20,000
tons take only one tenth of a millionth of a second. The problem thus
was to find a body that would remain immovable against an irresistible
force for no longer than one tenth of a microsecond, 100 billionths of a
second.
This immovable body is known technically as a “tamper,” which pits
inertia against an irresistible force that builds up in 100 billionths
of a second from an explosive power of 20 tons of TNT to 20,000 tons.
The very inertia of the tamper delays the expansion of the active
substance and makes for a longer-lasting, more energetic, and more
efficient explosion. The tamper, which also serves as a reflector of
neutrons, must be a material of very high density. Since gold has the
fifth highest density of all the elements (next only to osmium, iridium,
platinum, and rhenium), at one time the use of part of our huge gold
hoard at Fort Knox was seriously considered.
With these facts and figures in mind, it becomes clear that an H-bomb
made of deuterium alone is not feasible. It is certainly out of the
question with an A-bomb of the Hiroshima or Nagasaki types, which
generate a temperature of about 50,000,000 degrees, since, as we have
seen, it would take fully 200 microseconds to ignite it at that
temperature. It is one thing to devise a tamper that would hold back a
force of 20 tons for 100 billionths of a second, and thus allow it to
build up to 20,000 tons. It is quite another matter to devise an
immovable body that would hold back an irresistible force of 20,000 tons
for a time interval 2,000 times larger, particularly if one remembers
that in another tenth of a microsecond the irresistible force would
increase again by 1,000 to 20,000,000 tons. Obviously this is
impossible, for if it were possible we would have a superbomb without
any need for hydrogen of any kind.
It is known that we have developed a much more efficient A-bomb, which,
as Senator Edwin C. Johnson of Colorado has inadvertently blurted out,
“has six times the effectiveness of the bomb that was dropped over
Nagasaki.” We are further informed by Dr. Bacher that “significant
improvements” in atomic bombs since the war “have resulted in more
powerful bombs and in a more efficient use of the valuable fissionable
material.” It is conceivable and even probable that the improvements,
among other things, include better tampers that delay the new A-bombs
long enough to fission two, four, or even eight times as many atoms as
in the wartime models. But since, as we have seen, the ten steps of the
final stages require only an average of 10 billionths of a second per
step, increasing the power of the new models even to 160,000 tons (eight
times the power of the Hiroshima type) would take only three steps, in
an elapsed time of no more than 30 billionths of a second. And even if
we assume that the improved bomb generates a temperature of 200,000,000
degrees, it would still be too cold to ignite the deuterium during the
interval of its brief existence, since, as we have seen, it would take
4.8 microseconds to ignite it at that temperature. In fact, calculations
indicate that it would require a temperature in the neighborhood of
400,000,000 degrees to ignite deuterium in the time interval during
which the assembly of the improved A-bomb appears to be held together,
which, as may be surmised from the known data, is within the range of
1.2 microseconds.
From all this it may be concluded with practical certainty that an
H-bomb of deuterium only is out of the question. Equally good, though
entirely different, reasons also rule out an H-bomb using only tritium
as its explosive element.
There are several important reasons why an H-bomb made of tritium alone
is not feasible. The most important by far, which alone excludes it from
any serious consideration, is the staggering cost we would have to pay
in terms of priceless A-bomb material, as each kilogram of tritium
produced would exact the sacrifice of eighty times that amount in
plutonium. The reason for this is simple. Both plutonium and tritium
have to be created with the neutrons released in the splitting of U-235,
each atom of plutonium and each atom of tritium made requiring one
neutron. Since an atom of plutonium has a weight of 239 atomic mass
units, whereas an atom of tritium has an atomic weight of only three, it
can be seen that a kilogram, or any given weight, of tritium would
contain eighty times as many atoms as a corresponding weight of
plutonium, and hence would require eighty times as many neutrons to
produce. In other words, we would be buying each kilogram of tritium at
a sacrifice of eighty kilograms of plutonium, which, of course, would
mean a considerable reduction in our potential stockpile of plutonium
bombs.
We would cut this loss by more than half because a kilogram of tritium
would yield about two and a half times the explosive power of plutonium.
But even this advantage would soon be lost, since tritium decays at the
rate of fifty per cent every twelve years, so that a kilogram produced
in 1951 would decay to only half a kilogram by 1963. Plutonium, on the
other hand, can be stored indefinitely without any significant loss,
since it changes slowly (at the rate of fifty per cent every twenty-five
thousand years) into the other fissionable element, U-235, which in turn
decays to one half in no less than nine hundred million years. What is
more, plutonium, if the day comes when we can beat our swords into
plowshares, will become one of the most valuable fuels for industrial
power, the propulsion of ships, globe-circling airplanes, and even,
someday, interplanetary rockets. It holds enormous potentialities as one
of the major power sources of the twenty-first century. Tritium, on the
other hand, can be used only as an agent of terrible destruction. It
will yield its energy in a fraction of a millionth of a second or not at
all. The only other possible uses it may have would be as a research
tool for probing the structure of the atom, and as a potential new agent
in medicine, in which it may be used for its radiations.
How much tritium would it take to make an H-bomb 1,000 times the power
of the wartime model A-bombs? Since tritium has about 2.5 times the
power per given weight of U-235 or plutonium, it would take 400
kilograms (about 1,880 quarts of the liquid form) of tritium to make a
bomb that would equal the power of 1,000 kilograms of plutonium. Such a
bomb, we can see, would have to be made at the sacrifice of 32,000
kilograms of plutonium. In other words, we would be getting a return, in
terms of energy content, of 1,000 kilograms for an investment of 32,000.
And we would be losing fully half of even this small return every twelve
years.
How many A-bombs would we be sacrificing through this investment? On the
basis of Professor Oliphant’s estimate that the critical mass of an
A-bomb is between 10 and 30 kilograms, we would sacrifice at least
1,066, and possibly as many as 3,200, if we take the lower figure. And
we must not forget that a bomb a thousand times the power will produce
only ten times the destructiveness by blast and thirty times the damage
by fire of an A-bomb of the old-fashioned variety.
These cold facts make it clear that a tritium bomb, particularly one a
thousand times the power of the A-bomb, is completely out of the
picture.
But, one may ask, if a deuterium bomb is not possible and a tritium bomb
is not feasible, and these are the only two substances that can possibly
be used at all, isn’t all this talk about a superbomb sheer moonshine?
And if so, how explain President Truman’s directive “to continue” work
on it?
To find the answer let us go back for a moment to Dr. Bacher’s man in
the mountains, confronted with the problem of lighting a fire with
green, ice-covered wood at twenty degrees below zero with “very little
kindling.” Obviously the poor fellow would be doomed to freeze to death
were it not for one little item he had almost forgotten. Somewhere in
his belongings he discovers a container filled with gasoline, which
increases the inflammability of the wet wood to the point at which it
will catch fire with a quantity of kindling that would otherwise be much
too small.
Something closely analogous is true with the H-bomb. It so happens that
a mixture of deuterium and tritium is the most highly inflammable atomic
fuel on earth. It yields 3.5 times the energy of deuterium and about
twice the energy of tritium when they are burned individually. Most
important of all, the deuterium-tritium mixture, known as D-T, ignites
much faster than either deuterium or tritium by themselves. For example,
the D-T combination ignites 25 times faster than deuterium alone at a
temperature of 100,000,000 degrees, and the ignition time is fully 37.5
times faster than for deuterium at 150,000,000 degrees.
The published technical data show that at a temperature of 50 million
degrees the D-T mixture ignites in only 10 microseconds, or 20 times
faster than deuterium alone. At 75 million degrees it takes only 3
microseconds, as against 40 for deuterium, while at 100 million degrees
it needs only 1.2 microseconds to catch fire, a time, as we have seen,
only 0.1 microsecond longer than it took the wartime A-bomb to fly
apart. Since the latter held together for 1.1 microseconds at a
temperature of about 50 million degrees, it is reasonable to assume that
the improved and more efficient models generate a temperature at least
twice as high, and that this is done by holding them together for about
1.2 microseconds.
It can thus be deduced that the only feasible H-bomb is one in which a
relatively small amount of a deuterium-tritium mixture will serve as
additional superkindling, to boost the kindling supplied by the improved
model A-bomb, for lighting a fire with a vast quantity of deuterium.
This, it appears, is the real secret of the H-bomb, which is really no
secret at all, since all the deductions here presented are arrived at on
the basis of data widely known to scientists everywhere, including
Russia. And since it is no secret from the Russians, whom the
arch-traitor Fuchs has supplied with the details still classified top
secret, the American people are certainly entitled to the known facts,
so vitally necessary for an intelligent understanding of one of the most
important problems facing them today.
A deuterium bomb with a D-T booster would become a certainty if the
temperature of the A-bomb trigger could be raised to 150 million or,
better still, to 200 million degrees. At the former temperature the D-T
superkindling ignites in 0.38 microseconds; at the higher temperature
the ignition time goes down to as low as 0.28 microseconds. Now, the D-T
mixture releases four times as much energy as plutonium, and the faster
the time in which energy is released, the higher goes the temperature.
Since four times as much energy is released at a rate four times faster
than in the wartime model A-bomb, it is not unreasonable to assume that
the temperature generated would be high enough to ignite the green wood
in the bomb—its load of deuterium.
How much tritium would be required for the kindling mixture? On this we
can only speculate at present. Since the D-T kindling calls for the
fusion of one atom of tritium with one atom of deuterium, and the atomic
weight of tritium is three as compared with two for deuterium, the
weight of the two substances will be in the ratio of 3 for tritium to 2
for deuterium. Thus if the amount to be used for the kindling mixture is
to be one kilogram, it will be made up of 600 grams of tritium and 400
grams of deuterium. Since, as we have seen, it would take eighty
kilograms of plutonium to produce one kilogram of tritium, we would have
to use up only 48 kilograms of plutonium to create the 600 grams, or the
equivalent of one and a half to about five A-bombs, according to Dr.
Oliphant’s estimate.
But would we need as much as 600 grams of tritium? Such an amount, mixed
with 400 grams of deuterium, would yield an explosive power equal to
80,000 tons of TNT, an energy equivalent of 100 million kilowatt-hours.
A twentieth part of this amount would still be equal in power to 4,000
tons of TNT, equivalent in terms of energy to 5,000,000 kilowatt-hours.
Now one twentieth of 600 grams, just 30 grams of tritium, could be made
at a cost of no more than 2.4 kilograms of plutonium. Thus we would be
paying only one twelfth to one fourth of an A-bomb (in addition to the
one used as the trigger) to get the equivalent of ten A-bombs in
blasting power and of thirty times the incendiary power, which would
totally devastate an area of more than 300 square miles by blast and of
more than 1,200 square miles by fire.
Would 30 grams of tritium be enough to serve as the superkindling for
exploding, let’s say, 1,000 kilograms (one ton) of deuterium? We shall
probably not know until we actually try it. It will largely depend on
the temperature generated by our more powerful A-bomb models. If it is
true, as Senator Johnson informed his television audience, that they
have “six times the effectiveness of the bomb that was dropped over
Nagasaki” (which, by the way, had more than twice the effectiveness of
the Hiroshima model), it is quite possible that their temperature is as
high as 150 million, or even 200 million, degrees. In that case, the
extra kindling of a 20–30 gram D-T mixture, with its tremendous burst of
5,000,000 kilowatt-hours of energy in 0.28 to 0.38 microseconds (added
to the vast quantity already being liberated by the exploding plutonium,
or U-235), might well heat the deuterium to the proper ignition
temperature and keep it hot long enough for its mass to explode well
within 1.2 microseconds. In any case it would appear logical to expect
that a mixture of 150 grams of tritium and 100 grams of deuterium, which
would release an energy equal to that of the Hiroshima bomb, should be
able to do the job with plenty of time to spare.
We thus have a threefold answer to the question: Can the H-bomb
_actually_ be made? As we have seen, the deuterium bomb is definitely
not possible. The tritium bomb is theoretically possible, but definitely
not practicable. But a large deuterium bomb using a reasonably small
amount of a deuterium and tritium mixture as extra kindling is both
possible and feasible.
We now also stand on solid ground in dealing with the questions of cost
and of the time it would take us to get into production. With these
questions answered, we can then decide whether the H-bomb, if made, will
add enough to our security to make the effort worth while.
We know at this stage that the H-bomb requires three essential
ingredients. It needs, first of all, an A-bomb to set if off. We have a
sizable stockpile of them. It needs large quantities of deuterium. We
have built several deuterium plants during the war, and they should be
large enough to supply our needs. Since it is extracted from water, the
raw material will cost us nothing. The only item of cost will be the
electric power required for the concentration process, and this should
not be above $100 per kilogram, and probably less. The third vital
ingredient, tritium, can be made in the giant plutonium plants at
Hanford, Washington. Thus it can be seen that all the essential
ingredients of the H-bomb, the costliest and those that would take
longest to produce, as well as the multimillion-dollar plants required
for their production, are already at hand.
This means that as far as the essential materials are concerned, we are
ready to go right now. And as for the cost, it would appear to require
hardly any new appropriations by Congress, or, at any rate, only
appropriations that would be mere chicken feed compared with the five
billion we have already invested in our A-bomb program.
The raw material out of which tritium is made is the common, cheap light
metal lithium, the lightest, in fact, of all the metals. It has an
atomic weight of six, its nucleus consisting of three protons and three
neutrons. When an extra neutron invades its nucleus, it becomes unstable
and breaks up into two lighter elements, helium (two protons and two
neutrons) and tritium (one proton and two neutrons). They are both gases
and they are readily separated. And while lithium of atomic weight six
constitutes only 7.5 per cent of the element as found in nature (it
comes mixed with 92.5 per cent of lithium of atomic weight seven), there
is no need to separate it from its heavier twin, since the latter has no
affinity for neutrons and nearly all of them are gobbled up by the
lighter element.
The production of tritium, even in small amounts, will nevertheless be a
formidable process. As we have seen, it takes eighty times as many
neutrons to produce any given amount of tritium as to produce a
corresponding amount of plutonium. Since the lithium will have to
compete with uranium 238 (parent of plutonium) for the available supply
of neutrons, and since the number of atoms of U-238 per given volume is
nearly forty times greater than the number of lithium atoms, the rate of
tritium production would be very much slower than that of plutonium. On
the other hand, even if it took as much as two hundred times as long to
produce a given quantity of tritium, the handicap would be considerably
overcome because of the relatively small amounts that may be required.
If, for example, we should need only 30 to 150 grams of tritium per
bomb, it would take our present plutonium plants only six to thirty
times longer to produce these quantities than it takes them to produce
one kilogram of plutonium. A hypothetical plant such as the one
mentioned in the official Smyth Report, designed to produce one kilogram
of plutonium per day, would thus yield 30 grams of tritium in six days.
How much tritium would be needed for an adequate stockpile of H-bombs?
Since our primary reasons for building it are to deter aggression, to
prevent its use against us or our allies, and as a tactical weapon
against large land armies, it would appear that as few as twenty-five,
or fifty at the most, would be adequate for the purpose. On the basis of
the larger figure (assuming 30 to 150 grams of tritium per bomb), it
would mean an initial stockpile of only 1.5 to 7.5 kilograms of tritium,
which would entail the sacrifice of about 120 to 600 kilograms of
plutonium. Once this initial outlay had been made, however, our
plutonium sacrifice would be reduced annually to only one twenty-fourth
of the original respective amounts—namely, 5 to 25 kilograms a year—just
enough to make up for the decay of the tritium at the rate of fifty per
cent every twelve years.
One of the major problems to be solved, in addition to the main problem
of designing the assembly, arises from the fact that the deuterium and
the tritium booster will have to be in liquid form. Liquid hydrogen
boils (that is, reverts to gas) at a temperature of 423 degrees below
zero Fahrenheit under a pressure of one atmosphere (fifteen pounds per
square inch). To liquefy it, it is necessary to cool it in liquid air
(at 313.96 below zero F.) while keeping it at the same time under a
pressure of 180 atmospheres. To transport it, it must be placed in a
vacuum vessel surrounded by an outer vessel of liquid air. This would
point to the need of giant refrigeration and storage plants, as well as
of refrigerator planes for transporting large quantities of liquid
deuterium and its tritium spark plug.
Will the H-bomb, if made, add enough to our security to make the effort
worth while? We have seen that the required effort may, after all, not
be very great. In fact, it may turn out to be a relatively small one, in
view of the fact that all the basic ingredients and plants are already
at hand and fully paid for. But supposing even that the effort turns out
to be much more costly than it now appears? The question we must then
ask ourselves is: Can we afford not to make the effort?
It is true, of course, as some have pointed out, that ten or even fewer
A-bombs could destroy the heart of any metropolitan city, while only one
would be quite enough, as we know, for cities the size of Hiroshima or
Nagasaki. But that neglects to take into consideration the fact that one
H-bomb concentrates within itself the power of thirty A-bombs to destroy
by fire and by burns an area of more than 1,200 square miles at one
blow. Nor does it take into consideration the military advantage of
delivering the power of a combination of ten and thirty A-bombs in one
concentrated package, which would make it a tremendous tactical weapon
against a huge land army scattered over many miles, or its possible
enormous psychological effect against such an army.
Most important of all, this view grossly minimizes the apocalyptic
potentialities of the H-bomb for poisoning large areas with deadly
clouds of radioactive particles. It is a monstrous fact that an H-bomb
incorporating one ton of deuterium, encased in a shell of cobalt, would
liberate 250 pounds of neutrons, which would create 15,000 pounds of
highly radioactive cobalt, equivalent in their deadliness to 4,800,000
pounds of radium. Such bombs, according to Professor Harrison Brown,
University of Chicago nuclear chemist, could be set on a north-south
line in the Pacific approximately a thousand miles west of California.
“The radioactive dust would reach California in about a day, and New
York in four or five days, killing most life as it traverses the
continent.”
“Similarly,” Professor Brown stated in the _American Scholar_, “the
Western powers could explode H-bombs on a north-south line about the
longitude of Prague which would destroy all life within a strip 1,500
miles wide, extending from Leningrad to Odessa, and 3,000 miles deep,
from Prague to the Ural Mountains. Such an attack would produce a
‘scorched earth’ of an extent unprecedented in history.”
Professor Szilard, one of the principal architects of the A-bomb, has
estimated, as already stated, that four hundred one-ton deuterium bombs
would release enough radioactivity to extinguish all life on earth.
Professor Einstein, as we have seen, has publicly stated that the
H-bomb, if successful, will bring the annihilation of all life on earth
within the range of technical possibilities. The question we must
therefore ask ourselves is: Can we allow Russia to be the sole possessor
of such a weapon?
There can be no question that Russia is already at work on an H-bomb.
Like ourselves, she already has the plutonium plants for producing both
A-bombs and tritium. She can produce deuterium in the same quantities as
we can. In Professor Peter Kapitza she has the world’s greatest
authority on liquid hydrogen.
Furthermore, she has great incentives to produce H-bombs. Since she is
still behind us in her A-bomb stockpile, she can, in a sense, catch up
with us much more quickly by converting her fewer A-bombs into H-bombs
that would be the equivalents of ten to thirty A-bombs each, thus
increasing the power of her stockpile ten to thirty times. Equally if
not more important from Russia’s point of view is the stark fact that an
H-bomb could be much more easily exploded near a coastal city from a
submarine or innocent-looking tramp steamer, since most of our great
cities are on the seacoast, whereas Russia practically has no coastal
cities.
Even if we openly announced that we would not make any H-bombs, it would
not deter Russia from making them as fast as she could, not only because
she would not believe us but also because her sole possession would
greatly weight the scales in her favor. If, God forbid, she finds
herself one day with a stockpile of H-bombs when we have none, she would
be in a position to send us an ultimatum similar to the one we sent to
the Japanese after Hiroshima: “Surrender or be destroyed!”
Valuing their liberty more than their lives, the American people will
never surrender. But while there is time, would anyone advocate that we
run the risk of ever facing such a choice?
III
SHALL WE RENOUNCE THE USE OF THE H-BOMB?
A few days after President Truman announced that he had directed work
“to continue” on “the so-called hydrogen, or super bomb,” a group of
twelve eminent physicists, including half a dozen of the major
architects of the atomic bomb at Los Alamos, who, no doubt, are playing
a similar role in the development of the H-bomb, issued a statement
urging the United States to make “a solemn declaration that we shall
never use the bomb first,” and “that the only circumstances which might
force us to use it would be if we or our allies were attacked by _this_
bomb.” They added that “there can be only one justification for our
development of the hydrogen bomb, and that is to prevent its use.”
Signers of the statement, unprecedented in the annals of science (with
the possible exception of a secret memorandum submitted to the
government just before the A-bomb was used), included such outstanding
physicists as Hans A. Bethe of Cornell; Kenneth T. Bainbridge of
Harvard; Samuel K. Allison, University of Chicago; Dean George B.
Pegram, Columbia; C. C. Lauritsen, California Institute of Technology;
Bruno Rossi and Victor F. Weisskopf, Massachusetts Institute of
Technology; F. W. Loomis and Frederick Seitz, University of Illinois;
Merle A. Tuve, Carnegie Institution of Washington; R. B. Brode,
University of California; and M. G. White, Princeton—all, with the
exception of Dr. Tuve, professors of physics at their respective
universities. Those among them who did not directly participate in the
development of the A-bomb played major parts in other scientific wartime
projects, such as radar and the proximity fuse.
Implicit in their statement was the first confirmation—indeed, the most
authoritative we have had so far from scientists with first-hand
knowledge of the subject—that a hydrogen bomb of a thousand times the
power of the A-bomb could be made. More than that, they informed us that
Russia may complete the H-bomb in less than four years, meaning, of
course, that we too could achieve the same goal in the same period. We
were thus provided by the experts with a time-table on which we must act
if we are not to run the risk of Russia’s getting the H-bomb ahead of
us, and so being in a position to use it, or threaten its use, against
the nations of western Europe, as the greatest blackmail weapon in
history.
The statement summarizes in essence the principal points of view that
have been advanced so far on what policy we should adopt on the H-bomb,
and since it was promulgated by men known to have definite inside
knowledge of the subject, it deserves closer scrutiny than it has
hitherto received.
“It was stated correctly,” they inform us at the outset,
that a hydrogen bomb, if it can be made, would be capable of
developing a power 1,000 times greater than the present atomic bomb.
New York, or any of the greatest cities of the world, could be
destroyed by a single hydrogen bomb.
We believe that no nation has the right to use such a bomb, no matter
how righteous its cause. The bomb is no longer a weapon of war, but a
means of extermination of whole populations. Its use would be a
betrayal of morality and of Christian civilization itself.
Senator Brien McMahon has pointed out to the American people that the
possession of the hydrogen bomb will not give positive security to
this country. We shall not have a monopoly of this bomb, but it is
certain that the Russians will be able to make one, too. In the case
of the fission bomb the Russians required four years to parallel our
development. _In the case of the hydrogen bomb they will probably need
a shorter time._
We must remember that we do not possess the bomb but are only
developing it, and Russia has received, through indiscretion, _the
most valuable hint that our experts believe the development possible_.
Perhaps the development of the hydrogen bomb has already been under
way in Russia for some time. But if it was not, our decision to
develop it must have started the Russians on the same program. If they
had already a going program, they will redouble their efforts.
Statements in the press have given the power of the H-bomb as between
two and 1,000 times that of the present fission bomb. Actually, the
thermonuclear reaction on which the H-bomb is based is limited in its
power only by the amount of hydrogen which can be carried in the bomb.
Even if the power were limited to 1,000 times that of a present atomic
bomb, the step from an A-bomb to an H-bomb would be as great as that
from an ordinary TNT bomb to the atom bomb.
To create such an ever-present danger for all the nations of the world
is against the vital interests of both Russia and the United States.
Three prominent Senators have called for renewed efforts to eliminate
this weapon and other weapons of mass destruction from the arsenals of
all nations. Such efforts should be made, and made in all sincerity
from both sides.
In the meantime, we urge that the United States, through its elected
government, make a solemn declaration that we shall never use this
bomb first.
Before discussing in detail the merits of the proposal that the United
States renounce the use of the H-bomb, “no matter how righteous its
cause,” except in retaliation for its use against us or our allies, it
behooves us to examine the effect of our decisions to proceed with the
development of the H-bomb on Russia’s A-bomb progress.
We know that the H-bomb requires an A-bomb for its trigger. We also have
strong grounds for assuming that, in addition to the A-bomb, an H-bomb
will require certain quantities of tripleweight hydrogen, or tritium, as
extra superkindling to boost the A-bomb. We know, furthermore, that it
takes eighty times as many neutrons to make a given quantity of tritium
as it does to make a corresponding amount of plutonium, which, of
course, means a reduction in A-bombs.
Hence, should Russia decide to embark on an H-bomb program of her own,
or to “redouble her efforts,” it would lead inevitably to a serious
curtailment in her stockpile of A-bombs. While we would have to make the
same sacrifice of plutonium, it is obvious that we can afford the
sacrifice much better than Russia, since we already have a sizable
stockpile of both plutonium and uranium bombs, whereas she has just
begun building her stockpile. The situation for her would be much worse
if she has put all her atomic eggs in the plutonium basket without
bothering to build the much more complicated and costly uranium
separation plants, as the incomplete evidence available would seem to
indicate. In that case she would be faced with a serious dilemma indeed,
for you cannot have H-bombs without A-bombs, and you cannot have A-bombs
without plutonium, and if, as the evidence indicates, she has built her
A-bomb program exclusively around plutonium, she would have to sacrifice
quantities she could ill afford to spare, at this stage of her
development, of the only element she desperately needs for building up
her A-bomb stockpile.
How do we know that Russia’s A-bomb is made of plutonium? We have the
testimony of Senator Johnson of Colorado, who assured us in his famous
television broadcast of November 1, 1949 that “there’s no question at
all that the Russians have a bomb more or less similar to the bomb that
we dropped at Nagasaki, a plutonium bomb.” In this single sentence the
Senator from Colorado, who as a member of the Joint Congressional
Committee on Atomic Energy has access to such information, inadvertently
let at least three cats out of the bag. He confirmed that the Nagasaki
bomb was made of plutonium (though, in fairness, it must be said that
this had been known unofficially for some time); he told us that we had
found out not only that “an atomic explosion had occurred in the
U.S.S.R.,” as the President had announced in carefully chosen words, but
that the explosion was that of an atomic bomb and that, more important
still, the bomb was made of plutonium. And in doing so he, furthermore,
gave away the secret of how we had obtained that information, something
the Russians very much wanted to know. Not being a scientist, Senator
Johnson obviously did not realize that the split fragments (fission
products) of a plutonium bomb differ from those given off by the
explosion of a uranium bomb, so that in revealing that we knew what the
bomb was made of he would also be revealing at the same time that we
found it out by examining radioactive air samples and finding them to
contain fission fragments of plutonium, as well as whole plutonium atoms
that escaped fission.
There is thus no doubt that the Russians have built nuclear reactors for
producing plutonium from nonfissionable uranium 238. We cannot, of
course, be sure that they have not at the same time also built plants
for concentrating uranium 235, but the odds favor the negative. We built
uranium separation plants at Oak Ridge, Tennessee, and plutonium plants
at Hanford, Washington, during the war because we didn’t know at the
time which method would work, and we gambled on the chance that, by
building plants for producing fissionable materials by four different
methods, at least one of them might work. Had we known at the time that
the plutonium plants were practical, it is quite likely that we would
not have invested a billion dollars in building the uranium separation
plants. Since the Russians have obviously decided on plutonium plants as
the simplest and cheapest (three plutonium plants cost us a total of
$400,000,000, whereas a single large uranium separation plant cost half
a billion), it is hardly likely that they would consider it worth while
to invest in the much more costly uranium separation plants.
As Senator Johnson said in the same broadcast: “We tried out four
different methods of making a bomb and all of them succeeded, but one of
these methods was superior to all the others in simplicity and
effectiveness, and we told the Russians and we told the world that fact.
Of course, they didn’t have to make the experiments that we had to make
to find out by elimination which method was the most effective and which
the one that they should follow.”
The evidence is thus strongly in favor of the assumption that Russia has
only plutonium plants as her sole source of A-bomb material, whereas we
have both plutonium plants and gigantic uranium plants in full
operation. If that is so, then our forcing Russia to embark on an H-bomb
program, at a time when her A-bomb program is barely started, will place
her under a double handicap in her race to catch up with us in A-bombs,
and at least to keep abreast of us, if not ahead, in H-bombs. For in
this grim race we have a dual if not a triple advantage: our much
superior stockpile, both in numbers and no doubt in quality, and our
gigantic plants for concentrating U-235, the production of which would
not have to be curtailed at all, since tritium can be made only in
plutonium plants. In fact, we are now in the process of construction of
two great additions to the uranium plant at Oak Ridge.
One may visualize the masters of the Kremlin gnashing their teeth in
impotent rage at what they no doubt regard as a diabolical plot on our
part to sabotage their A-bomb effort. Indeed, there can be no question
that our decision to proceed with the H-bomb was an answer to Russia’s
challenge to our atomic supremacy, and it appears quite plausible that
one of the motives behind the decision was the knowledge that it would
force Russia either to build great additions to her atomic plants, at
great expense in money and materials and at the loss of considerable
precious time, or to curtail her production of A-bomb material. And
while any such motive could not possibly have been the determining
factor, the ultimate effect of our decision was the same as though we
had succeeded in getting a team of expert saboteurs behind the Iron
Curtain to plant a good-sized monkey wrench in the Soviet atomic
machinery.
With this in mind we begin to appreciate how dangerous a move it would
be, to ourselves and to world peace, if we were to make a solemn
declaration at the outset, even before we have a single H-bomb, that we
will never use it, “no matter how righteous our cause,” unless it is
used first against us or our allies. By making such a unilateral
declaration, without even making it conditional upon Russia issuing a
similar solemn renunciation, we would, in effect, be saying to Russia:
“We humbly beg your pardon. We did not realize that we would be putting
a nasty monkey wrench in the machinery of your vital A-bomb program. We
shall remove the wrench at once so that you may proceed with your
program unhindered by us in any way.”
The masters of the Kremlin would, indeed, have every right to laugh long
and loud, and to take such foolhardy action on our part as further
evidence of what they call “the decadence of the bourgeois democracies.”
For, once we make such a magnanimous unilateral solemn renunciation of
the one weapon that promises to become the greatest single deterrent
against war, without even bothering to ask Russia publicly to do
likewise, Russia could then proceed calmly at her leisure to build up
her A-bomb stockpile, with the complete assurance from us that she need
not worry about our H-bomb as long as she does not use one against us or
our allies. After she has accumulated an adequate A-bomb stockpile—and
fifty to one hundred would be adequate from her standpoint—she would
then be in a position, already attained by us now, to proceed with her
H-bomb program, knowing full well that we would never use H-bombs
against her while she is still without them. And while she obviously
could not use anything she does not have, she could well afford to make
aggressive war even before she has an H-bomb, or to bide her time until
she does, the choice being entirely hers. And if she waits until she has
the H-bomb, the decision whether to use it or not would still be
entirely hers, so that she could use it whenever she decides it is to
her advantage to do so, whereas we should have to wait on her pleasure,
having morally bound ourselves, without qualification, not to use it
first, even if our very existence depended on it.
It can thus be easily seen that this “after you, my dear Alphonse”
gesture on our part in a matter that may involve our very existence
would be more than quixotic. It is likely to prove suicidal. It will not
improve the prospects of world peace; on the contrary it will weaken
them. It will not enhance our moral stature, since the world does not
have much respect for starry-eyed dreamers with their heads in the
clouds.
But while we must keep our feet planted on the ground, we need not lose
sight of the stars. Our refusal to expose ourselves by giving Russia the
great advantages mentioned, does not mean that we retain the right to
use the H-bomb indiscriminately as though it were just another weapon.
There are, I shall presently show, both legitimate and illegitimate uses
to which the H-bomb can be put, and it is the failure so far, even by
eminent scientists, to distinguish between these two types of possible
uses that is responsible for a great deal, if not all, of the confusion
and much futile debate that have followed the President’s announcement
of his directive to continue work on the hydrogen bomb, and for the
flood of verbiage that will continue to plague and bewilder us until we
take time to acquaint ourselves with the facts about the H-bomb.
One of the major difficulties in our approach to the subject stems from
the general tendency to talk about the H-bomb as though it were just one
weapon, which obviously it is not. As we know, it is several weapons in
one package, which can be designed for various uses, depending on the
intent of its designer. It is, on the one hand, a weapon that can cause
total destruction by blast over a radius of ten miles, or an area of
more than 300 square miles, with graduated lesser damage over a much
larger area. Secondly, it is a weapon that can produce fires and severe
flash burns over a radius of twenty miles—that is, over an area of more
than 1,200 square miles. These two functions, destruction by blast and
by fire, go together. They are inseparable as far as the bomb itself is
concerned, though their relative effects can be regulated by the height
from which the bomb is dropped, by the terrain over which it is used,
and by its mode of delivery other than by air.
Then, of course, there is the third weapon of terror, the tremendous
quantities of deadly radioactive particles that the H-bomb may release
in the atmosphere, which, as Dr. Einstein said, would bring within the
range of technical possibilities “the annihilation of life on earth.”
This, however, would depend on the choice and purpose of the designer.
If he so chooses, he can design an H-bomb that would produce only
slightly greater radioactivity than its A-bomb trigger. Or he can rig it
in such a manner that one bomb would release into the atmosphere the
equivalent of nearly five million pounds of radium that would poison the
atmosphere for thousands of miles, killing all life wherever it goes.
The catchword here is “rig,” and the rigging depends entirely, not on
the contents of the bomb itself, but on the material of which its outer
shell is composed. If, for example, the casing chosen is a material such
as steel, the radioactivity produced would be practically harmless. If
the shell is made of cobalt, the radiations released would cause untold
havoc. The reason for the vast difference is not difficult to
understand. The H-bomb, when it explodes, releases tremendous quantities
of neutrons, the most penetrating particles in nature. As soon as it is
liberated, a neutron enters the nucleus of the nearest element at hand.
This may produce a wide variety of changes in the nature of the element
penetrated by the neutron, the changes depending on the element. Some
elements, such as cobalt, become intensely radioactive, others only
mildly so, and still others not at all. Furthermore, each element thus
made radioactive has its own characteristic decay period, lasting from
seconds to many years, so that the designer of the bomb has a great
variety to choose from.
From this it can be seen that, instead of one, there are actually two
types of H-bombs—the non-rigged and the rigged. With this vital
distinction in mind the problem of its use becomes much more simplified.
We are in a position to reach full agreement with the scientists that no
nation has the right to use such a “rigged” bomb, no matter how
righteous its cause. For the rigged H-bomb would add nothing to the
military value of the non-rigged H-bomb, which is already more than
enough to achieve any military objective. It would merely be piling
horror upon horror for no purpose beyond wanton destruction for its own
sake. Its use even in small numbers would ruin large segments of the
earth for years. It would, as the scientists said, “be a betrayal of
morality and of Christian civilization itself.” There can therefore be
no question that when this distinction between the non-rigged and the
rigged H-bomb is made clear to the American people—something the
scientists failed to do—they would overwhelmingly lend their support to
a move on the part of our government solemnly declaring that we would
never use the rigged H-bomb first; that our only aim in building it is
to prevent its use, and that the only circumstances under which we would
find ourselves forced to use it would be in retaliation for its use
against us or our allies.
We can, and should, make such a solemn declaration unilaterally,
regardless of whether Russia makes a similar declaration. We would lose
nothing by doing so from a military or strategic point of view, and we
would gain enormously in moral stature and on the battlefront of ideas
if we were to do it now. Otherwise we run the risk that Russia might do
it first. If she takes advantage of this lost opportunity of ours, we
shall have handed her a great moral victory. In fact, the law of nations
compels us to make such a declaration. Unlike the A-bomb, in which the
radioactivity is part and parcel of the bomb itself, the rigged H-bomb
is purposely designed to produce radioactive poisoning in the
atmosphere. Since it has to be specially incorporated into the casing of
the bomb, it comes under the international convention outlawing the use
of poison gas. For there can be no question that a radioactive cloud
that may lay waste to whole areas is the most diabolical and deadly
poison gas so far invented.
But the twelve scientists do not seem to be satisfied with the mere
renunciation of the rigged H-bomb. They ask us to declare that we would
not be the first to use even the non-rigged bomb, on the grounds that it
“is no longer a weapon of war, but a means of extermination of whole
populations.” This requires closer scrutiny.
It has become customary to think of the A-bomb, and now of the H-bomb,
as purely strategic weapons for destroying industrial centers producing
war materials, thus depriving the armies at the front of the vital
sinews of war. It is also regarded as a weapon of superterror to bring a
nation to its knees, as the A-bomb did in Japan. Since industrial
centers, particularly in the United States, are densely populated areas,
and since, conversely, all large cities are also important industrial
centers, it has become almost axiomatic that the A-bomb and the H-bomb
could be used only in strategic bombing of large centers of population,
which, of course, means the wholesale slaughter of millions of civilians
and the wiping out of cities with populations of more than 200,000.
But to think along such lines would be thinking of World War III, which
we must do our utmost to prevent, in terms of World War II, which would
be just as fatal as thinking in terms of World War I was to the French
in World War II. For even a cursory examination of the situation should
reveal that strategic bombing of cities may, and very likely would be,
as obsolete in the next war as trench warfare was in the last. One does
not have to be a military expert to know the reason why. In the last war
strategic bombing was resorted to in order to deprive the army at the
front of weapons and supplies. Obviously, if you had a superweapon that
could wipe out an entire army in the field or on the march at one blow,
there would be no further need of depriving an army that was no longer
in being.
That is exactly what the non-rigged H-bomb is. As a blast weapon, we
have seen, it can cause total destruction of everything within an area
of more than 300 square miles. As an incinerator it would severely burn
everything within an area of more than 1,200 square miles. It is thus
the tactical weapon par excellence. No army in the field or on the march
could stand up against it. Had we possessed it at the Battle of the
Bulge, just one could have wiped out the entire Bulge. If the Nazis had
had it before D-Day, one would have been enough to wipe out our entire
invasion army even before it landed; or they could have waited and wiped
out our entire Normandy beachhead. In a word, the non-rigged H-bomb has
produced a major revolution in tactics and strategy. It has made
strategic bombing of cities as obsolete as the trench of World War I,
except as a weapon of pure terror and wanton wholesale destruction of
life and property. It would be absolutely useless to the victor as well
as to the vanquished, as the victor would have no spoils of victory left
and would have to rebuild what he had needlessly destroyed.
Viewed in this light, the non-rigged H-bomb, just because it is the
weapon for the annihilation of armies, becomes vis-à-vis Russia, the
greatest deterrent against war that could possibly be devised in the
present state of affairs. For, after all, the only great advantage
Russia has over us today is her land army and her great reserve of
manpower. The non-rigged H-bomb, supported by a large and up-to-date air
force capable of delivering it either by air or from a seized airhead
behind the lines, could nullify that advantage in a few hours. At least
the threat of such a possibility will always be there. It is therefore
doubtful, to say the least, that any group of men would willingly take
such a risk.