[After the flash of the atomic bomb test explosion] Fermi got up and dropped small pieces of paper … a simple experiment to measure the energy liberated by the explosion … [W]hen the front of the shock wave arrived (some seconds after the flash) the pieces of paper were displaced a few centimeters in the direction of propagation of the shock wave. From the distance of the source and from the displacement of the air due to the shock wave, he could calculate the energy of the explosion. This Fermi had done in advance having prepared himself a table of numbers, so that he could tell immediately the energy liberated from this crude but simple measurement. … It is also typical that his answer closely approximated that of the elaborate official measurements. The latter, however, were available only after several days’ study of the records, whereas Fermi had his within seconds.

[Misquotation; not by Einstein.] If only I had known, I should have become a watchmaker. [Apparently remorseful for his role in the development of the atom bomb.]

[The surplus of basic knowledge of the atomic nucleus was] largely used up [during the war with the atomic bomb as the dividend.] We must, without further delay restore this surplus in preparation for the important peacetime job for the nucleus - power production. ... Many of the proposed applications of atomic power - even for interplanetary rockets - seem to be within the realm of possibility provided the economic factor is ruled out completely, and the doubtful physical and chemical factors are weighted heavily on the optimistic side. ... The development of economic atomic power is not a simple extrapolation of knowledge gained during the bomb work. It is a new and difficult project to reach a satisfactory answer. Needless to say, it is vital that the atomic policy legislation now being considered by the congress recognizes the essential nature of this peacetime job, and that it not only permits but encourages the cooperative research-engineering effort of industrial, government and university laboratories for the task. ... We must learn how to generate the still higher energy particles of the cosmic rays - up to 1,000,000,000 volts, for they will unlock new domains in the nucleus.

[W]e have made a thing, a most terrible weapon, that has altered abruptly and profoundly the nature of the world. We have made a thing that, by all standards of the world we grew up in, is an evil thing. And by doing so, by our participation in making it possible to make these things, we have raised again the question of whether science is good for man, of whether it is good to learn about the world, to try to understand it, to try to control it, to help give to the world of men increased insight, increased power. Because we are scientists, we must say an unalterable yes to these questions; it is our faith and our commitment, seldom made explicit, even more seldom challenged, that knowledge is a good in itself, knowledge and such power as must come with it.

—Aaaah!!! Une explosion nucleaire!
—Oui…On appelle ça le soleil.
—Aaaah!!! A nuclear explosion!
—Yes…It’s called the sun.

[When asked “Dr. Einstein, why is it that when the mind of man has stretched so far as to discover the structure of the atom we have been unable to devise the political means to keep the atom from destroying us?”] That is simple, my friend. It is because politics is more difficult than physics.

A stands for atom; it is so small No one has ever seen it at all.
B stands for bomb; the bombs are much bigger,
So, brother, do not be too fast on the trigger.
H has become a most ominous letter.
It means something bigger if not something better.

A Thousand Paper Cranes. Peace on Earth and in the Heavens.

Anyone who thinks we can continue to have world wars but make them nice polite affairs by outlawing this weapon or that should meditate upon the outlawing of the cross-bow by Papal authority. Setting up the machinery for international law and order must surely precede disarmament. The Wild West did not abandon its shooting irons till after sheriffs and courts were established.

Anyway, I'm sort of glad they’ve got the atomic bomb invented. If there’s ever another war. I’m going to sit right the hell on top of it. I’ll volunteer for it, I swear to God I will.

As the Director of the Theoretical Division of Los Alamos, I participated at the most senior level in the World War II Manhattan Project that produced the first atomic weapons.
Now, at age 88, I am one of the few remaining such senior persons alive. Looking back at the half century since that time, I feel the most intense relief that these weapons have not been used since World War II, mixed with the horror that tens of thousands of such weapons have been built since that time—one hundred times more than any of us at Los Alamos could ever have imagined.
Today we are rightly in an era of disarmament and dismantlement of nuclear weapons. But in some countries nuclear weapons development still continues. Whether and when the various Nations of the World can agree to stop this is uncertain. But individual scientists can still influence this process by withholding their skills.
Accordingly, I call on all scientists in all countries to cease and desist from work creating, developing, improving and manufacturing further nuclear weapons - and, for that matter, other weapons of potential mass destruction such as chemical and biological weapons.
[On the occasion of the 50th Anniversary of Hiroshima.]

But of all environments, that produced by man’s complex technology is perhaps the most unstable and rickety. In its present form, our society is not two centuries old, and a few nuclear bombs will do it in.
To be sure, evolution works over long periods of time and two centuries is far from sufficient to breed Homo technikos… .
The destruction of our technological society in a fit of nuclear peevishness would become disastrous even if there were many millions of immediate survivors.
The environment toward which they were fitted would be gone, and Darwin’s demon would wipe them out remorselessly and without a backward glance.

But when you come right down to it, the reason that we did this job is because it was an organic necessity. If you are a scientist you cannot stop such a thing. If you are a scientist you believe that it is good to find out how the world works; that it is good to find out what the realities are; that it is good to turn over to mankind at large the greatest possible power to control the world and to deal with it according to its lights and values.
Regarding the atomic bomb project.

By God’s mercy British and American science outpaced all German efforts. … This revelation of the secrets of nature, long mercifully withheld from man, should arouse the most solemn reflections in the mind and conscience of every human being capable of comprehension. We must indeed pray that these awful agencies will be made to conduce to peace among the nations, and that instead of wreaking measureless havoc upon the entire globe, may become a perennial fountain of world prosperity.
[Concerning use of the atomic bomb.]

Dear Dr. Pauling, Will you be so kind as to stay off precipitous cliffs until the question of disarmament and atomic testing is finished? A needy citizen.

Despite the vision and the far-seeing wisdom of our wartime heads of state, the physicists felt a peculiarly intimate responsibility for suggesting, for supporting, and in the end, in large measure, for achieving the realization of atomic weapons. Nor can we forget that these weapons, as they were in fact used, dramatized so mercilessly the inhumanity and evil of modern war. In some sort of crude sense which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.

Every inhabitant of this planet must contemplate the day when this planet may no longer be habitable. Every man, woman and child lives under a nuclear sword of Damocles, hanging by the slenderest of threads, capable of being cut at any moment by accident or miscalculation or by madness. The weapons of war must be abolished before they abolish us.

For they have sown the wind, and they shall reap the whirlwind.

Genetic engineering is to traditional crossbreeding what the nuclear bomb was to the sword.

Groves hated the weather, and the weathermen; they represented chaos and the messengers of chaos. Weather violated boundaries, ignored walls and gates, failed to adhere to deadlines, disobeyed orders. Weather caused delays. The weather forecasters had opposed the [atomic bomb] test date for months—it was set within a window of unfavorable conditions: thunderstorms, rain, high winds, inversion layers. Groves had overridden them. … Groves saw it as a matter of insubordination when the weather forecasters refused to forecast good weather for the test.

Hitherto man had to live with the idea of death as an individual; from now onward mankind will have to live with the idea of its death as a species.

I am become death, The Shatterer of Worlds.

I call upon the scientific community in our country, those who gave us nuclear weapons, to turn their great talents now to the cause of mankind and world peace, to give us the means of rendering those nuclear weapons impotent and obsolete.
About his proposed Strategic Defense Initiative, later to be known as 'Star Wars.')

I first met J. Robert Oppenheimer on October 8, 1942, at Berkeley, Calif. There we discussed the theoretical research studies he was engaged in with respect to the physics of the bomb. Our discussions confirmed my previous belief that we should bring all of the widely scattered theoretical work together. … He expressed complete agreement, and it was then that the idea of the prompt establishment of a Los Alamos was conceived.”

I have always fancied that the end of the world will be when some enormous boiler, heated to three thousand millions of atmospheric pressure, shall explode and blow up the globe. ... They [the Americans] are great boilermakers.

I remember the spring of 1941 to this day. I realized then that a nuclear bomb was not only possible—it was inevitable. … And I had then to start taking sleeping pills. It was the only remedy, I’ve never stopped since then. It’s 28 years, and I don’t think I’ve missed a single night in all those 28 years.

I will have nothing to do with a bomb!
[Response to being invited (1943) to work with Otto Robert Frisch and some British scientists at Los Alamos during the Manhattan Project to create the atomic bomb.]

I’m not saying we wouldn’t get our hair mussed, Mr. President, but I do say not more than ten to twenty million dead depending upon the breaks.

If atomic bombs are to be added as new weapons to the arsenals of a warring world, or to the arsenals of nations preparing for war, then the time will come when mankind will curse the names of Los Alamos and Hiroshima. The people must unite, or they will perish.

If Russia is to be a great power, it will be, not because of its nuclear potential, faith in God or the president, or Western investment, but thanks to the labor of the nation, faith in knowledge and science and the maintenance and development of scientific potential and education.

If some nuclear properties of the heavy elements had been a little different from what they turned out to be, it might have been impossible to build a bomb.

If we stay strong, then I believe we can stabilize the world and have peace based on force. Now, peace based on force is not as good as peace based on agreement, but … I think that for the time being the only peace that we can have is the peace based on force.

Imagine a room awash in gasoline, and there are two implacable enemies in that room. One of them has nine thousand matches. The other has seven thousand matches. Each of them is concerned about who's ahead, who's stronger. Well that's the kind of situation we are actually in. The amount of weapons that are available to the United States and the Soviet Union are so bloated, so grossly in excess of what's needed to dissuade the other, that if it weren't so tragic, it would be laughable. What is necessary is to reduce the matches and to clean up the gasoline.

In 1945, therefore, I proved a sentimental fool; and Mr. Truman could safely have classified me among the whimpering idiots he did not wish admitted to the presidential office. For I felt that no man has the right to decree so much suffering, and that science, in providing and sharpening the knife and in upholding the ram, had incurred a guilt of which it will never get rid. It was at that time that the nexus between science and murder became clear to me. For several years after the somber event, between 1947 and 1952, I tried desperately to find a position in what then appeared to me as a bucolic Switzerland,—but I had no success.

In an enterprise such as the building of the atomic bomb the difference between ideas, hopes, suggestions and theoretical calculations, and solid numbers based on measurement, is paramount. All the committees, the politicking and the plans would have come to naught if a few unpredictable nuclear cross sections had been different from what they are by a factor of two.

In answer to the question, “Was the development of the atomic bomb by the United States necessary?” I reply unequivocally, “Yes.” To the question, “Is atomic energy a force for good or for evil?” I can only say, “As mankind wills it.”

In discussing the state of the atmosphere following a nuclear exchange, we point especially to the effects of the many fires that would be ignited by the thousands of nuclear explosions in cities, forests, agricultural fields, and oil and gas fields. As a result of these fires, the loading of the atmosphere with strongly light absorbing particles in the submicron size range (1 micron = 10^-6 m) would increase so much that at noon solar radiation at the ground would be reduced by at least a factor of two and possibly a factor of greater than one hundred.

In scientific matters there was a common language and one standard of values; in moral and political problems there were many. … Furthermore, in science there is a court of last resort, experiment, which is unavailable in human affairs.

In the beginning there was an explosion. Not an explosion like those familiar on earth, starting from a definite center and spreading out to engulf more and more of the circumambient air, but an explosion which occurred simultaneously everywhere, filling all space from the beginning, with every particle of matter rushing apart from every other particle. ‘All space’ in this context may mean either all of an infinite universe, or all of a finite universe which curves back on itself like the surface of a sphere. Neither possibility is easy to comprehend, but this will not get in our way; it matters hardly at all in the early universe whether space is finite or infinite. At about one-hundredth of a second, the earliest time about which we can speak with any confidence, the temperature of the universe was about a hundred thousand million (10¹¹) degrees Centigrade. This is much hotter than in the center of even the hottest star, so hot, in fact, that none of the components of ordinary matter, molecules, or atoms, or even the nuclei of atoms, could have held together. Instead, the matter rushing apart in this explosion consisted of various types of the so-called elementary particles, which are the subject of modern high­energy nuclear physics.

In this age of space flight, when we use the modern tools of science to advance into new regions of human activity, the Bible ... this grandiose, stirring history of the gradual revelation and unfolding of the moral law ... remains in every way an up-to-date book. Our knowledge and use of the laws of nature that enable us to fly to the Moon also enable us to destroy our home planet with the atom bomb. Science itself does not address the question whether we should use the power at our disposal for good or for evil. The guidelines of what we ought to do are furnished in the moral law of God. It is no longer enough that we pray that God may be with us on our side. We must learn again that we may be on God's side.

It did not take atomic weapons to make man want peace. But the atomic bomb was the turn of the screw. The atomic bomb made the prospect of future war unendurable. It has led us up those last few steps to the mountain pass; and beyond there is a different country.

It is arguable whether the human race have been gainers by the march of science beyond the steam engine. Electricity opens a field of infinite conveniences to ever greater numbers, but they may well have to pay dearly for them. But anyhow in my thought I stop short of the internal combustion engine which has made the world so much smaller. Still more must we fear the consequences of entrusting a human race so little different from their predecessors of the so-called barbarous ages such awful agencies as the atomic bomb. Give me the horse.

It is hard to think of fissionable materials when fashioned into bombs as being a source of happiness. However this may be, if with such destructive weapons men are to survive, they must grow rapidly in human greatness. A new level of human understanding is needed. The reward for using the atom’s power towards man’s welfare is great and sure. The punishment for its misuse would seem to be death and the destruction of the civilization that has been growing for a thousand years. These are the alternatives that atomic power, as the steel of Daedalus, presents to mankind. We are forced to grow to greater manhood.

It is only when science asks why, instead of simply describing how, that it becomes more than technology. When it asks why, it discovers Relativity. When it only shows how, it invents the atom bomb, and then puts its hands over its eye and says, 'My God what have I done?

It is probable that all heavy matter possesses—latent and bound up with the structure of the atom—a similar quantity of energy to that possessed by radium. If it could be tapped and controlled, what an agent it would be in shaping the world's destiny! The man who puts his hand on the lever by which a parsimonious nature regulates so jealously the output of this store of energy would possess a weapon by which he could destroy the Earth if he chose.
A prescient remark on atomic energy after the discovery of radioactivity, but decades before the harnessing of nuclear fission in an atomic bomb became a reality.

Knowing he [Bob Serber] was going to the [first atom bomb] test, I asked him how he planned to deal with the danger of rattlesnakes. He said, “I’ll take along a bottle of whiskey.” … I ended by asking, “What would you do about those possibilities [of what unknown phenomena might cause a nuclear explosion to propagate in the atmosphere]?” Bob replied, “Take a second bottle of whiskey.”

Let us sum up the three possible explanations of the decision to drop the bomb and its timing. The first that it was a clever and highly successful move in the field of power politics, is almost certainly correct; the second, that the timing was coincidental, convicts the American government of a hardly credible tactlessness [towards the Soviet Union]; and the third, the Roman holiday theory [a spectacular event to justify the cost of the Manhattan Project], convicts them of an equally incredible irresponsibility.

May there not be methods of using explosive energy incomparably more intense than anything heretofore discovered? Might not a bomb no bigger than an orange be found to possess a secret power to destroy a whole block of buildings—nay, to concentrate the force of a thousand tons of cordite and blast a township at a stroke? Could not explosives even of the existing type be guided automatically in flying machines by wireless or other rays, without a human pilot, in ceaseless procession upon a hostile city, arsenal, camp or dockyard?

Most kids can't understand why a country that makes atomic bombs would ban fireworks.

Non-violence … is the only thing that the atom bomb cannot destroy.

Now we’re all sons-of-bitches.

Nuclear weapons offer us nothing but a balance of terror, and a balance of terror is still terror.

Often in evolutionary processes a species must adapt to new conditions in order to survive. Today the atomic bomb has altered profoundly the nature of the world as we know it, and the human race consequently finds itself in a new habitat to which it must adapt its thinking.

On 17th July there came to us at Potsdam the eagerly-awaited news of the trial of the atomic bomb in the [New] Mexican desert. Success beyond all dreams crowded this sombre, magnificent venture of our American allies. The detailed reports ... could leave no doubt in the minds of the very few who were informed, that we were in the presence of a new factor in human affairs, and possessed of powers which were irresistible.

One might be led to question whether the scientists acted wisely in presenting the statesmen of the world with this appalling problem. Actually there was no choice. Once basic knowledge is acquired, any attempt at preventing its fruition would be as futile as hoping to stop the earth from revolving around the sun.

One must expect a war between U.S.A. and U.S.S.R. which will begin with the total destruction of London. I think the war will last 30 years, and leave a world without civilised people, from which everything will have to build afresh—a process taking (say) 500 years.
Stated just one month after the Hiroshima atomic explosion. Russell became one of the best-known antinuclear activists of his era.

One of the striking things about places heavily contaminated by radioactive nuclides is the richness of their wildlife. This is true of the land around Chernobyl, the bomb test sites of the Pacific, and areas near the United States’ Savannah River nuclear weapons plant of the Second World War. Wild plants and animals do not perceive radiation as dangerous, and any slight reduction it may cause in their lifespans is far less a hazard than is the presence of people and their pets.

One would have to have been brought up in the “spirit of militarism” to understand the difference between Hiroshima and Nagasaki on the one hand, and Auschwitz and Belsen on the other. The usual reasoning is the following: the former case is one of warfare, the latter of cold-blooded slaughter. But the plain truth is that the people involved are in both instances nonparticipants, defenseless old people, women, and children, whose annihilation is supposed to achieve some political or military objective.… I am certain that the human race is doomed, unless its instinctive detestation of atrocities gains the upper hand over the artificially constructed judgment of reason.

Our papers have been making a great deal of American “know-how” ever since we had the misfortune to discover the atomic bomb. There is one quality more important than know-how” and we cannot accuse the United States of any undue amount of it. This is “know-what,” by which we determine not only how to accomplish our purposes, but what our purposes are to be.

Personally I think there is no doubt that sub-atomic energy is available all around us, and that one day man will release and control its almost infinite power. We cannot prevent him from doing so and can only hope that he will not use it exclusively in blowing up his next door neighbour. (1936)

Qualified scientists in Washington believe that the atom-blasting of Japan is the start toward heating plants the size of telephone booths for great factories, and motor-car trips of 1,000 hours on one gram of fuel. One expert estimated that with a few grams of uranium it might be possible to power the Queen Mary from Europe to the U.S. and back again. One of America’s leading scientists, Doctor Vollrath, said that the new discovery brings man’s attempt to reach the moon within bounds of possibility.

Radiation, unlike smoking, drinking, and overeating, gives no pleasure, so the possible victims object.

REST IN PEACE. THE MISTAKE SHALL NOT BE REPEATED.

Science has nothing to be ashamed of even in the ruins of Nagasaki. The shame is theirs who appeal to other values than the human imaginative values which science has evolved. The shame is ours if we do not make science part of our world...

Science has taught us how to put the atom to work. But to make it work for good instead of for evil lies in the domain dealing with the principles of human duty. We are now facing a problem more of ethics than physics.

Scientists, therefore, are responsible for their research, not only intellectually but also morally. This responsibility has become an important issue in many of today's sciences, but especially so in physics, in which the results of quantum mechanics and relativity theory have opened up two very different paths for physicists to pursue. They may lead us—to put it in extreme terms—to the Buddha or to the Bomb, and it is up to each of us to decide which path to take.

Should a scientist consider possible ramifications of his research and their effects on society,…? Answer: I think it is impossible for anybody, scientist or not, to foresee the ramifications. We might say that that is a definition of basic science. Vide Einstein’s discovery of 1905 of the equivalence of mass and energy and the development of atomic weaponry. … CONSIDER RAMIFICATIONS? IMPOSSIBLE.

So far as I can see the atomic bomb has deadened the finest feeling that has sustained mankind for ages.

Some men said the atomic bomb should never have been built; researchers should have stopped working when they had realized that the bomb was feasible. Enrico did not think this would have been a sensible solution. It is no good trying to stop knowledge from going forward. Whatever Nature has in store for mankind, unpleasant as it may be, men must accept, for ignorance is never better than knowledge.
Note: Although attributed as his viewpoint to Enrico Fermi, it is probably not a direct quote by him.

Some recent work by E. Fermi and L. Szilard, which has been communicated to me in manuscript, leads me to expect that the element uranium may be turned into a new and important source of energy in the immediate future. Certain aspects of the situation seem to call for watchfulness and, if necessary, quick action on the part of the Administration. …
In the course of the last four months it has been made probable … that it may become possible to set up nuclear chain reactions in a large mass of uranium, by which vast amounts of power and large quantities of new radium-like elements would be generated. Now it appears almost certain that this could be achieved in the immediate future.
This new phenomenon would also lead to the construction of bombs, and it is conceivable—though much less certain—that extremely powerful bombs of a new type may thus be constructed. A single bomb of this type, carried by boat or exploded in a port, might well destroy the whole port altogether with some of the surrounding territory. However, such bombs might well prove to be too heavy for transportation by air.

Such explosives [atomic bombs] in men’s hands, while their moral and intellectual status is declining, is about as useful as giving out firearms to all inmates of a gaol and then saying that you hope ‘this will ensure peace’.

Suddenly, there was an enormous flash of light, the brightest light I have ever seen or that I think anyone has ever seen. It blasted; it pounced; it bored its way into you. It was a vision which was seen with more than the eye. It was seen to last forever. You would wish it would stop; altogether it lasted about two seconds.
[Witnessing the first atomic bomb test explosion.]

That atomic energy though harnessed by American scientists and army men for destructive purposes may be utilised by other scientists for humanitarian purposes is undoubtedly within the realm of possibility. … An incendiary uses fire for his destructive and nefarious purpose, a housewife makes daily use of it in preparing nourishing food for mankind.

That is the biggest fool thing we have ever done. The [atomic] bomb will never go off, and I speak as an expert in explosives.
[A skeptical comment on the U.S. Atomic Bomb Project, to President Harry S. Truman in 1945.]

The atom bomb was no “great decision.” It was used in the war, and for your information, there were more people killed by fire bombs in Tokyo than dropping of the atomic bombs accounted for. It was merely another powerful weapon in the arsenal of righteousness. The dropping of the bombs stopped the war, save millions of lives.

The Atomic Age began at exactly 5.30 Mountain War Time on the morning of July 15, 1945, on a stretch of semi-desert land about 50 airline miles from Alamogordo, New Mexico. And just at that instance there rose from the bowels of the earth a light not of this world, the light of many suns in one. ... At first it was a giant column that soon took the shape of a supramundane mushroom.
On the first atomic explosion in New Mexico, 16 Jul 1945.

The Atomic Age was born in secrecy, and for two decades after Hiroshima, the high priests of the cult of the atom concealed vital information about the risks to human health posed by radiation. Dr. Alice Stewart, an audacious and insightful medical researcher, was one of the first experts to alert the world to the dangers of low-level radiation.
(Udeall is a former U.S. Secretary of the Interior.)

The conflict that exists today is no more than an old-style struggle for power, once again presented to mankind in semireligious trappings. The difference is that, this time, the development of atomic power has imbued the struggle with a ghostly character; for both parties know and admit that, should the quarrel deteriorate into actual war, mankind is doomed.

The double horror of two Japanese city names [Hiroshima and Nagasaki] grew for me into another kind of double horror; an estranging awareness of what the United States was capable of, the country that five years before had given me its citizenship; a nauseating terror at the direction the natural sciences were going. Never far from an apocalyptic vision of the world, I saw the end of the essence of mankind an end brought nearer, or even made, possible, by the profession to which I belonged. In my view, all natural sciences were as one; and if one science could no longer plead innocence, none could.

The dropping of the Atomic Bomb is a very deep problem… Instead of commemorating Hiroshima we should celebrate… man’s triumph over the problem [of transmutation], and not its first misuse by politicians and military authorities.

The explosion of the Alamogordo bomb ended the initial phase of the MED project: the major technical goal had been achieved …. The feat will stand as a great monument of human endeavor for a long time to come.

The future of mankind is going to be decided within the next two generations, and there are two absolute requisites: We must aim at a stable-state society [with limited population growth] and the destruction of nuclear stockpiles. … Otherwise I don't see how we can survive much later than 2050.

The ginkgo tree is from the era of dinosaurs, but while the dinosaur has been extinguished, the modern ginkgo has not changed. After the atomic bomb in Hiroshima, the ginkgo was the first tree that came up. It’s amazing.

The human race may well become extinct before the end of the century. Speaking as a mathematician, I should say the odds are about three to one against survival.

The key to the utilization of atomic energy for world peace will be found in the will of all people to restrict its use for the betterment of mankind.

The most striking impression was that of an overwhelming bright light. I had seen under similar conditions the explosion of a large amount—100 tons—of normal explosives in the April test, and I was flabbergasted by the new spectacle. We saw the whole sky flash with unbelievable brightness in spite of the very dark glasses we wore. Our eyes were accommodated to darkness, and thus even if the sudden light had been only normal daylight it would have appeared to us much brighter than usual, but we know from measurements that the flash of the bomb was many times brighter than the sun. In a fraction of a second, at our distance, one received enough light to produce a sunburn. I was near Fermi at the time of the explosion, but I do not remember what we said, if anything. I believe that for a moment I thought the explosion might set fire to the atmosphere and thus finish the earth, even though I knew that this was not possible.

The news today about ‘Atomic bombs’ is so horrifying one is stunned. The utter folly of these lunatic physicists to consent to do such work for war-purposes: calmly plotting the destruction of the world!

The nuclear arms race is like two sworn enemies standing waist deep in gasoline, one with three matches, the other with five.
[A summary version; not verbatim.]

The object of the project is to produce a practical military weapon in the form of a bomb in which the energy is released by a fast neutron chain reaction in one or more of the materials known to show nuclear fission.

The only use for an atomic bomb is to keep somebody else from using one. It can give us no protection—only the doubtful satisfaction of retaliation.

The position in which we are now is a very strange one which in general political life never happened. Namely, the thing that I refer to is this: To have security against atomic bombs and against the other biological weapons, we have to prevent war, for if we cannot prevent war every nation will use every means that is at their disposal; and in spite of all promises they make, they will do it.

The prediction of nuclear winter is drawn not, of course, from any direct experience with the consequences of global nuclear war, but rather from an investigation of the governing physics. (The problem does not lend itself to full experimental verification—at least not more than once.)[co-author with American atmospheric chemist Richard P. Turco (1943- )]

The release of atomic energy has not created a new problem. It has merely made more urgent the necessity of solving an existing one … I do not believe that civilization will be wiped out in a war fought with the atomic bomb. Perhaps two thirds of the people of the Earth would be killed.

The unleashed power of the atom has changed everything save our modes of thinking and we thus drift toward unparalleled catastrophe.

The use of the atomic bomb with its indiscriminate killing of women and children, revolts my soul.

The world has achieved brilliance without wisdom, power without conscience. Ours is a world of nuclear giants and ethical infants. We know more about war than we know about peace, more about killing than we know about living.

The world is a very different one now. For man holds in his mortal hands the power to abolish all forms of human poverty, and all forms of human life.

There was a loudspeaker that reported on the time left before the blast: “T-minus ten minutes”—something like that. The last few seconds were counted off one by one. We had all turned away. At zero there was the flash. I counted and then turned around. The first thing I saw was a yellow-orange fireball that kept getting larger. As it grew, it turned more orange and then red. A mushroom-shaped cloud of glowing magenta began to rise over the desert where the explosion had been. My first thought was, “My God, that is beautiful!”

This man, one of the chief architects of the atomic bomb, so the story runs, was out wandering in the woods one day with a friend when he came upon a small tortoise. Overcome with pleasurable excitement, he took up the tortoise and started home, thinking to surprise his children with it. After a few steps he paused and surveyed the tortoise doubtfully.
“What's the matter?” asked his friend.
Without responding, the great scientist slowly retraced his steps as precisely as possible, and gently set the turtle down on the exact spot from which he had taken him.
Then he turned solemnly to his friend. “It just struck me,” he said, “that, perhaps for one man, I have tampered enough with the universe.” He turned, and left the turtle to wander on its way.

This weapon [the atomic bomb] has added an additional responsibility—or, better, an additional incentive—to find a sound basis for lasting peace. It provides an overwhelming inducement for the avoidance of war. It emphasizes the crisis we face in international matters and strengthens the conviction that adequate safeguards for peace must be found.

Those of us who saw the dawn of the Atomic Age that early morning at Alamogordo … know now that when man is willing to make the effort, he is capable of accomplishing virtually anything.

To my knowledge there are no written accounts of Fermi’s contributions to the [first atomic bomb] testing problems, nor would it be easy to reconstruct them in detail. This, however, was one of those occasions in which Fermi’s dominion over all physics, one of his most startling characteristics, came into its own. The problems involved in the Trinity test ranged from hydrodynamics to nuclear physics, from optics to thermodynamics, from geophysics to nuclear chemistry. Often they were closely interrelated, and to solve one’it was necessary to understand all the others. Even though the purpose was grim and terrifying, it was one of the greatest physics experiments of all time. Fermi completely immersed himself in the task. At the time of the test he was one of the very few persons (or perhaps the only one) who understood all the technical ramifications.

Today when the public thinks of the products of science it is likely to think about environmental problems, an unproductive armament industry, careless or dishonest 'scientific' reports, Livermore cheers for 'nukes forever' and a huge amount of self-serving noise on every subject from global warming to 'the face of God'.

Uranium and Atomica Melancholica Idyll.

We have an A-bomb … What more do you want, mermaids?

We have genuflected before the god of science only to find that it has given us the atomic bomb, producing fears and anxieties that science can never mitigate.

We have many men of science; too few men of God. We have grasped the mystery of the atom and rejected the Sermon on the Mount.

We have seen that a proton of energy corresponding to 30,000 volts can effect the transformation of lithium into two fast α-particles, which together have an energy equivalent of more than 16 million volts. Considering the individual process, the output of energy in the transmutation is more than 500 times greater than the energy carried by the proton. There is thus a great gain of energy in the single transmutation, but we must not forget that on an average more than 1000 million protons of equal energy must be fired into the lithium before one happens to hit and enter the lithium nucleus. It is clear in this case that on the whole the energy derived from transmutation of the atom is small compared with the energy of the bombarding particles. There thus seems to be little prospect that we can hope to obtain a new source of power by these processes. It has sometimes been suggested, from analogy with ordinary explosives, that the transmutation of one atom might cause the transmutation of a neighbouring nucleus, so that the explosion would spread throughout all the material. If this were true, we should long ago have had a gigantic explosion in our laboratories with no one remaining to tell the tale. The absence of these accidents indicates, as we should expect, that the explosion is confined to the individual nucleus and does not spread to the neighbouring nuclei, which may be regarded as relatively far removed from the centre of the explosion.

We scientists are clever—too clever—are you not satisfied? Is four square miles in one bomb not enough? Men are still thinking. Just tell us how big you want it!

We will be misguided in our intentions if we point at one single thing and say that it will prevent war, unless, of course, that thing happens to be the will, the determination, and the resolve of people everywhere that nations will never again clash on the battlefield.

What a curious picture it is to find man, homo sapiens, of divine origin, we are told, seriously considering going underground to escape the consequences of his own folly. With a little wisdom and foresight, surely it is not yet necessary to forsake life in the fresh air and in the warmth of sunlight. What a paradox if our own cleverness in science should force us to live underground with the moles.

What the scientists have in their briefcases is terrifying.

When you see something that is technically sweet, you go ahead and do it and you argue about what to do about it only after you have had your technical success. That is the way it was with the atomic bomb.

Without birds to feed on them, the insects would multiply catastrophically. ... The insects, not man or other proud species, are really the only ones fitted for survival in the nuclear age. ... The cockroach, a venerable and hardy species, will take over the habitats of the foolish humans, and compete only with other insects or bacteria.

You can stop splitting the atom; you can stop visiting the moon; you can stop using aerosols; you may even decide not to kill entire populations by the use of a few bombs. But you cannot recall a new form of life.