Atomic Bombs

Atomic bomb is an explosive device in which a large amount of energy is released through nuclear reactions. This makes an atomic bomb, more properly called a nuclear weapon, a much more powerful device than any conventional bomb containing chemical explosives. The first Atomic Bombs were used during World War 2 in 1945 by the US onto 2 Japanese cities.

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World War 2
Harry Truman
Atomic Bombs

Why did Truman decide to use the atomic bomb against Japan?

he thought it would be a funny bruh moment

Atomic Bombs

Who invented atomic bombs?

Leo Szilard, a Hungarian Jew living in London at the time, in 1933. He patented it in 1934, the patent GB630726 was granted in 1936 and immediately classified to prevent Nazi Germany from using it. It took 12 more years before the US was able to build the first ones, after an enormous investment in industrial infrastructure. Szilard's patent was not made public until 1949. During WW2 this was done under the Manhattan Project. There was a large team of scientists, the chief one was Dr Robert Oppenheimer.

Professor Rudolph Peierls and Otto Frisch were also involved.

The atomic bomb was originally invented in 1940 by German scientists, Professor Rudolph Peierls and Otto Frisch who were both working for Britain at the time.
During World War II, the United States, with the assistance (collaboration) of physicists, mathematicians, and engineers from the U.S., Britain, Canada and Europe, completed the Manhattan Project to produce the first atomic bomb.

(The project started as the "Manhattan District Engineers" and only became "The Manhattan Project" some time later).

There was some early speculation about the possibility of what could be done if a nuclear chain reaction was unleashed in a way that would allow it to build without control. For a roll call, consider that Robert Oppenheimer was the head of "science" for the Manhattan Project, and (in alphabetical order) Felix Block, David Bohm, Niels Bohr, Enrico Fermi, James Franck, Otto Frisch, Klaus Fuchs, Rudolf Peierls, Emilio Segre, Leo Szilard, Edward Teller and Eugene Wigner all played crucial roles in getting the weapon designed and built.

The physicist Albert Einstein did not participate directly in the invention of the atomic bomb-but was instrumental in facilitating its development. His Special Theory of Relativity emphasized that a large amount of energy could be released from a small amount of matter. This was expressed by the equation E=mc2 (energy = mass times the speed of light squared). The atomic bomb would clearly illustrate this principle.

The first demonstration of "the gadget" (the code name for the first atomic bomb) was at Trinity site in Alamogordo, New Mexico, and it proved that the weapon would detonate and that the chain would build as predicted. The second and third demonstrations were conducted in Japan, which brought a quick end to the Second World War. Just up to and during World War 2, Germany was also working to develop atomic weapons, but was hampered by many technical and political problems (including sabotage and Allied bombings) which prevented their successfully completing their work. This left the U.S. as the only nation to ever unleash nuclear weapons in an attack.
The first fission weapons, also known as "atomic bombs," were developed jointly by the United States, Britain and Canada during World War II in what was called the Manhattan Project. (Wikipedia)

Leo Szilard invented the atomic bomb in 1933 while crossing a London street. He patented it in 1934. (British patent 630,726)

The Manhattan Project built the first one in 1945.
Robert oppenheimer
the united states made the atomic bomb

World War 2
Japan in WW2
Hiroshima and Nagasaki Atomic Bombings
Atomic Bombs

What are arguments for and against the atomic bombings of Japan being justified?

Here are summaries of opinions from FAQ Farmers on the moral or immoral nature of the decision to bomb Japan with nuclear weapons. Fewer Americans died * The war in the Pacific had been raging for almost four years. The two battles immediately preceeding the bomb decision were Iwo Jima and Okinawa, two battles where the Japanese fought to the death and the cost in American casualties was horrific. It was predicted that the invasion of the Japanese mainland at the Island of Kyushu -- scheduled for November of 1945 -- would be even worse. The entire Japanese military and civilian population would fight to the death. American casualties -- just for that initial invasion to get a foothold on the island of Japan would have taken up to an estimated two months and would have resulted in up to 75,000 to 100,000 casualties -- up to 20,000 dead! And that was just the beginning. Once the island of Kyushu was captured by U.S. troops, the remainder of Japan would follow. You can just imagine the cost in injuries and lives this would take. * Estimated US casualties for Operation OLYMPIC & CORONET were 250,000 along with 1,000,000 Japanese civilian casualties. In the parlance of the young, "this is a no-brainer." * It is not beyond the possibility that a million or more Americans could have been killed had we landed. The Japanese had correctly guessed where we intended to land, and were ready and waiting for us. The casualties would have been high. One American tanker walked around the area he was to have assaulted had we landed. According to him most of the "roads" marked on his map were not roads, but simply foot paths. He felt that tanks would have played a very small part in the fighting. It would have been more fighting against caves, and suicide attacks. * The bomb was dropped with a desire to SAVE LIVES. It is a matter of math. How many Americans lost their lives fighting how many Japanese at Tarawa, Iwo Jima, Okinawa. The mathematical formula showed the closer we got to Japan the more we lost. Next, one must calculate how many Japanese military people were still in Japan. Add to that figure the fact that women were being trained to fight. Before you say the women would not fight please remember that many women on Okinawa committed suicide fearing all the stories they were told about what the Americans would do to them if they surrendered. * Perhaps your grandfathers were among the 18-26 year old American GI's who had managed to survive the war in Europe. If so, on August 6, 1945, they were with approximately a million other boys on the way to the Pacific. At least 50-80% of them were expected to die in the invasion of the Japanese home islands. Since most of these young men were not yet married, your grandfathers had not yet married your grandmothers, so if they did not come back, then your parents would never be born and therefore you would not be here to second-guess historical decisions. * People can argue all they want about what the true U.S. government estimates of U.S. casualties in an invasion of Japan were. Doesn't matter. I can guarantee you that 99.9% of the soldiers, sailors and airmen involved in the actual combat, or training for the upcoming invasion were convinced that the invasion of Japan would be a bloodbath. I have never heard or read of any American military person who was involved in the late stages of fighting in the war with Japan who was not glad that the atomic bombs were dropped to end the war. Japanese civilians died * Yes, war is war, and death in war is redundant, you must realize, that death in war is only legal if it is military death and not civilian death, unless the civilians pick up arms and fight back (then in that case they would be considered combatants). * To say that the U.S. was justified in dropping the bombs, one would have to believe the maxim "the end justifies the means." * Bombs in general should seldom be used especially those of this magnitude. Fewer Japanese civilians died * The largest number of people killed in a single B-29 raid was not at Hiroshima, but at Tokyo, with conventional firebombs. Some 80,000-100,00 people killed. The problem was that even with the savage firebombing, the pathetic idiot military elite that was in charge of Japan DIDN'T CARE! They didn't care how much suffering their people had to endure. Surrender was NOT going to happen! Real men, real samurai NEVER SURRENDER! The voices of reason calling for surrender, for beginning negotiations with America were shouted down. Thus, more than anything else, the atomic bomb gave Emperor Hirohito the "face-saving" boost that he needed to tell these idiots that the time had come for Japan to surrender. It was one thing to surrender in the face of battle against an enemy with conventional bombs and weapons. It was another thing to face the seemingly supernatural force of atomic weapons. No matter that the atomic bombs actually killed fewer Japanese per city and were thus LESS EFFECTIVE than conventional firebombs. No, atomic weapons were a supernatural force that the Americans now controlled and so this was a good reason to stop fighting finally. * When you compare with simple math, the dropping of the bombs took less lives than if we had tried to invade Japan. That's true for Japanese lives as well as American lives. Japanese lives were saved as a direct result of those bombs. * The Japanese casualties (not including mass suicides as seen on Okinawa) were expected to be 5 to 10 times that of the Allies in an invasion. As many as 20 million Japanese men, women and children might have died in a bloody invasion. Saving lives in a worthy goal. Sadly some had to die that others might live. * While the atomic bombs, just as ANY bombs, were an unpleasant way to die, in the long run it saved lives and brought WW 2 to an end. Six long and costly years of world-wide death and destruction came to an end, thanks to the courageous decision made by President Truman. * How many Japanese would have died as we invaded the islands of Japan? Every city could have been leveled, every rice paddy, all utilities, sewers, etc. What bullets and bombs didn't kill the diseases that followed would finish. Certainly that figure would have exceeded those that died BY FAR all those that died from the two bombs dropped. * After having fought through Iwo Jima, Saipan, Guam, and Okinawa, there was no doubt that the Japanese people and their leaders would fight until the last man, woman, and child. If the Emperor had not instructed his subjects to stop fighting after Nagasaki they were prepared to resist tanks and artillery with sticks and stones until the last man, woman, and child perished. * An invasion of the Japanese mainland would have been a blood-bath for both sides. One could ask if cutting off the arm of a man is just. If that arm has gangrene and will kill the man slowly if not amputated, then it is indeed just. It does not matter that the arm is "innocent." Radiation is more horrible than conventional bombs * The radiation released from the bombs is still causing problems in Japan today. Many people died because of exposure to radiation. I understand that the people back then did not know the effects of an atomic explosion, they just thought that they were super bombs. And I also acknowledge the fact that invading Japan itself will cause high casualties on both sides. But, civilians are not suppose to protect the soldiers with their lives, it is the other way around! In a war, the deaths of 1 million soldiers are better than the death of 1 civilian, because civilians are innocent and soldiers are not. Surrendered soldiers are also innocent. I know that many soldiers were conscripted and do not want to fight, well too bad, blame the war. * The atomic bomb leaves behind radiation. And not just where the bomb exploded, the wind carried the particles around. The radiation is what makes the bomb so controversial. Yes, the US achieved its goals, but, after the bombings and up to 4 months afterwards, tens of thousands of people died of illness directly related to radiation poisoning. Is this justifiable by saying that more people would have died if the US invaded Japan? Maybe it is, I'm not saying it isnt, but the thing is, even if more people died, dying of radiation sickness or watching as the skin melt off of you is much worse than being shot to death, or dying while fighting to protect the land you love. * Can you really compare any type of bombing to atomic bombing which does have the factor of radiation poisioning which lead to cancers such as Leukemia. Does anybody deserve this destroyer of lives to be dropped on them? Several women had the intricate designs from their Kimonos burned into their flesh! The US wanted to kill as many civilians as possible * The bombs were nothing more than senseless civilian casualties in an already bloody war. * Supposedly the U.S. used the bomb on a military target. The reality is that Hiroshima was chosen not because there was a weapons plant nearby, but because it was a highly populated urbanized city. The site was chosen to showcase the full destructive power that the U.S. had available. Hiroshima and Nagasaki were military targets * One may think that the US chose to bomb the most populated areas only to kill many innocent civilians, but this is ridiculous to anyone who has studied history. The two cities of Hiroshima and Nagasaki were chosen because they were industrialized and military ports. All nations in WWII killed civilians * Like it or not there was little distinction between civilians and soldiers in WWII owing to the industrial nature of the war. The military could not operate without a functioning civilian economic base. All the major players targeted industry, communication and transportation of their opponents. This is in addition to directly attacking civilians in the hope of fostering terror. Of all the nations the U.S. had the luck of geography that Germany and Japan really could not hit the mainland US. They tried. * This was World War II. Bombs were dropped. People died. It happened in most participant nations and most of them dropped bombs of their own. If they didn't, it was only because they didn't have any to drop. I cannot for the life of me understand what difference it makes what type of bomb was dropped by whom. Japan wanted to bomb the US * The Japanese had a secret atomic bomb project. Is there any doubt they would have use it if they had succeeded in perfecting the bomb? The Japanese were not innocent * Just four years earlier the Japanese invaded us at Pearl Harbor without warning, bringing the US into World War II. We at least gave Japan a warning and they still wouldn't surrender. It had to be done. * Read "Rape of Nanking", a book about Japanese atrocities in China during WWII. Talk to some of the older people of China, Korea, Singapore, etc. who experienced WWII at the hands of the Japanese military. I would challenge you to find a single Asian person of that generation with personal experience of the Japanese invasions of their country who is not PROFOUNDLY GLAD that Japan got atomic bombed. My personal references in this case are my own parents and my two in-laws. Uniformly, their response to this would be: "Yes! Japan deserved getting atomic bombed!" To this day, the people of Asia have still not forgotten or forgiven Japan for its many atrocities of WWII and earlier. * The dropping of the atomic bombs on Japan has allowed the Japanese to maintain this myth that THEY were just as much victims of WWII as all the people of Asia and the Allied soldiers who died at their hands. Has anybody ever wondered why Germany does not have similar fantasies of victimhood? We have the Holocaust to "thank" for this. The death camps in Germany were kept as monuments to Nazi atrocities and the Nuremberg trials exposed the war criminals. Only the most egregious Japanese war criminals were put on trial. The bombings had nothing to do with Japan, it was about the Cold War * The real reason America used these weapons was to show Russia that the US possessed them. There would have been a Soviet occupation * The invasion was set for November 1, 1945. By that time, the USSR would have fought long enough to have a say in the partition of the Japanese island group and perhaps even Tokyo itself. The impact of Soviet occupation upon Japan and the part it could have played in Korea and the Cold War cannot be calculated. All war is unjust * I'm not sure anyone person is capable of answering this question. If you ask a Japanese or German who lost family members during the bombing of Hiroshima or firebombing of Dresden, you might get a different answer. Then ask a London resident during the bombing and rocket attacks of WW2 and see what he or she says. * Was dropped the atomic bombs a nice, humane thing to do? No, it has been a long time if ever that warfare has been a noble art. Did it save lives in the long run? Yes. * It is very hard to walk in the shoes of the people who made the decisions in 1945 especially when some of the greatest "concerns" people have today are what Paris Hilton is wearing or who just got booted off of Survivor. * I believe the notions of Just and Unjust are incompatible with war. Moral standards are created to facilitate civilian societies. Any attempt at reasoning within the same conceptual framework during a war collapses immediately. Formally, the USA had a right to drop the bomb, by international law of the time. Her territories had been violated and there was a state of war. The USA committed no crime of any national or international kind when dropping the A bombs. In fact, the USA was not even subject to international conventions in her relation to Japan, as Japan had not signed any. Even if the USA had been subject to Geneva and Hague in her relation with Japan, as she unilaterally declared herself to feel, the only applicable rule would have been proportionality. * In war, the objective is to defeat your enemy and keep your own men alive. The point of war is to win, not to make friends. I'm sorry if you see this as a cold response, but when it comes to war, the moral thoughts that govern society are not the same morals that govern the military. Japan was already losing * Japan was losing in 1945. It was only a matter of time before Japan lost the war. The bombings ended the war * Japan was not about to fold. The military attempts to prevent the emperor from capitulating are an indication of this. * As is not always realized, the U.S. asked Japan to surrender before the dropping of the first bomb, and yet we got no response after the first bomb, thus as a result, we dropped our last atomic bomb on Nagasaki, resulting in Japan's full surrender. * Justification is so often seen by various sides of the argument from their own perspective. What seems just to one side is dismissed by another. Truman's decision to drop the bombs was undoubtedly right. Even after the second bomb was detonated, the Japanese still did not surrender for another week! The US kept up round the clock bombing by B-29s until the moment of surrender. * Even after Hirohito made the tape of his speech of surrender, to be broadcast the following day, a group of diehard military officers attempted a coup and tried to snatch the tape. General Mori of the Imperial Guards was murdered in the coup (he refused to divulge the location of the tape), the plotters were unable to find the tape, and the coup failed. Japan was in the grip of fanatics. The United States in the latter days of WW2 was faced with a terrible dilemma. The Japanese are a proud, courageous and determined people. Japanese men, women and children were willing to die for the emperor. The invasion of Japan was necessary to end the war, because the Japanese would "lose face" if they considered surrender. In August of 1944 the war in Europe was over and the face off between the United States and Japan had finally arrived. The United States had to choose between sending hundreds of thousands of US soldiers, many freshly off the battlefields of Europe, to invade Japan killing and being killed by the hundreds of thousands, or dropping a newly developed weapon called the atomic bomb on two cities in Japan which would result in tens of thousands of civilian lives with little cost to US servicemen. The only hope of ending the war quickly and honorably was to drop the bombs. Calls for surrender were ignored and repugnent to the Japanese hierarchy; Okinawa and Iwo Jima had shown clearly what an invasion of Japan would be like. The decision was made, the bombs were dropped, the war was ended and both military and civilian lives were saved by both countries. !03,000 people died at the time and a further 1000 over the next 30 years, although many are living (and dying) with the effects.

World War 2
Japan in WW2
US in WW2
Atomic Bombs

Where the first atomic bomb was thrown?

Hiroshima and Nagasaki.

World War 2
Japan in WW2
US in WW2
Atomic Bombs

What was the second plane that drop a atomic bomb in world war 2?

The B-29 bomber 'Bockscar', dropped the second atomic bomb named 'Fat Man' upon the Japanese city of Nagasaki .

Desserts, Snacks, and Treats
Atomic Bombs

Can Twinkies survive atomic bombs?

no, they cannot. Twinkies are made from dairy, and dairy eventually expires. they are also made from matter, that can easily be digested, so whats stopping it from being obliterated?

Japan in WW2
Atomic Bombs

Why did the US drop the atomic bombs on Japan?

Here are explanations:

  • To put an immediate end to the war
  • The USA was facing the prospect of invading Japan to subdue it. The last few battles, Iwo Jima and Okinawa particularly, were incomprehensibly bloody. Japan had no regard for its own citizens' lives and planned to turn their whole island into a fortress. It was estimated that casualties would be 1 million Americans and half a million British in the first invasion alone. Some cynics say we used it to scare Stalin as well, but the fact remains that they ignored an ultimatum on 27 July 1945 after enduring the worst conventional bombs could do. A powerful argument remains that the Bomb saved allied and Japanese lives.


The Allies demanded unconditional surrender of the Axis. In the Pacific Theater, the Allies, led by the United States, rolled up the Japanese expansion island by island. When Guam was taken, the Allies had a base from which stage an invasion. The estimates of American casualties for an invasion of mainland Japan was in excess of 1 million Americans. Possibly in excess of 2 million Americans. The United States dropped two atomic bombs to save American lives and speed the end of the war. Prior to using the atomic bomb, Japan was given ultimatums to surrender along with warnings of the dire consequences. The Japanese government ignored the warnings. While the use of the atomic bomb was a technological and strategic turning point in both WWII and all future diplomatic and strategic activities, there were more people killed, maimed, and injured during the Tokyo firebombing campaigns than by the atomic bomb.

To force Japan to surrender without further fighting. Japan surrendered very quickly thus saving the lives of over 100,000 American soldiers and perhaps as many as 1,000,000 Japanese who would have died if we had invaded Japan.

The Allies utilized atomic weapons to bring Japan to her knees. As an American, how hard would you fight an enemy if they were invading our nation? I mean literally on the soil of our 50 states? Then imagine how hard EVERY Japanese citizen, man, woman AND child, would be trying to kill OUR men, as we invade their nation.

Tensions were starting to build up in Europe between Soviet Union and its western allies. Since USSR had an overwhelming numerical superiority there, a show of force was needed to convince Stalin to "behave". Besides, the Russians were preparing for an invasion of Japan. I think these considerations were at least as valid back then as saving American lives.

According to some sources, Japan had a military force of over 9 million soldiers. Through battles like Midway, Okinawa, Iwo Jima, Guadacanal, and other "island-hopping" battles, 1.5 million soldiers either were killed or wounded enough so they couldn't fight. That meant that if Operation Olympic (the invasion of the main island of Japan) were to occur we would have to fight every soldier we had defeated before four times over!

Even if we hadn't of dropped the atomic bomb, Hiroshima and Nagasaki would still have been targets for attack. This is because Hiroshima was a large industrial city that contained the 2nd Japanese Army Headquarters, which was in charge of all the defense systems in Southern Japan; Hiroshima also had communication centers for armies, storage points, and troop assemblies. Small industrial plants were also in the outskirts of the city. As for Nagasaki, it was the largest fully operational sea port in Southern Japan, which produced ships, equipment, and relief supplies. There is much other information that can be explained about the reality of dropping the bomb on Japan and this was one 'chunk' of information.

I agree with the guys who were talking about conserving American army resources and manpower. At Iwo Jima there were nearly 30,000 marines KIA. The Japanese lost nearly all of their army there. Imagine that in a place with cities, etc and bigger armies in a homeland .Even if you guys won, the Japanese would never forgive you. More deaths would have been caused than the bombs, and in more cities.

The fact that a lot of Japanese fought to the death because they were never given a chance to surrender, and the fact that after Pearl harbor 13% of Americans said in a poll (13% of voting Americans, that is) that the only acceptable outcome of the war to them was the death of every Japanese man woman and child. Then there are slogans like, "kill Japs, kill Japs and kill more Japs" and somebody said how the main language in Hell by the end would be Japanese.

The Yanks were furious for Pearl Harbor and revenge is the most dangerous reason for fighting for both sides. The Japanese are brave people who see honor in death if the death is good (not in all death, though. Any fool can die in battle. True courage is living when it is right to live and dying when it is right to die). So, IMO, the A-bomb was used to reduce the expected casualty rate and loss of resources (tanks, weapons, etc all cost the taxpayers and government a lot of money) and I'm guessing it probably did for both sides.

World War two ended on August 10, 1945 only four after the Little Boy uranium bomb was dropped on Hiroshima and one day after the Fat Man plutonium bomb was dropped on Nagasaki.

Combined, approximately 128,000 died just due to the massive concussion and explosions caused by the bombs, and about 120,000 suffered from radiation sickness and cancer, many of whom died afterwards. The question is, was it really necessary to drop two atomic bombs on Japan to get them to surrender?

My answer is yes, because of several factors. One is the culture of the Japanese at the time. For centuries the Japanese had a warrior class called the samurai. The samurai followed Bushido, or the way of the warrior, which was an honor code that preaches that honor, duty, and loyalty to the emperor and local warlord are the absolute virtues that can be achieved.

As a result, a loss of honor would mean that the dishonored samurai would be expected to commit Seppuku, or ritualistic suicide, which involves a samurai taking his sword, stabbing himself with it, and cutting out his own liver. The wound was very painful and could take quite a while to die from, anywhere from a few minutes to a week.

The most common way in which a samurai could be dishonored would be by being defeated in battle. However, fighting to the last man and arrow (or in this case, round of ammo) and holding ones position till the death was considered a great honor.

Does this sound like a nation that is willing to give up? By the last years of the war, everyone, men and women, over the age of thirteen was a part of a sort of National Guard, and were under the same rules as the rest of the military, which was in turn fighting under a modified code of Bushido which dictated that they never surrender and leave behind the wounded.

Another aspect of Japan's culture was that of a group mentality. About ninety-nine percent of the Japanese people were, at the time of World War 2, direct decedents from the original nomadic Mongolian tribes that crossed over into Japan from the Korean Peninsula. They inhabited a land of which only twenty percent was flat enough to farm. Entire towns had to work together to maintain tiny rice paddies carved into hillsides that were irrigated by a community network.

Disagreement among the common people against their ruler or with each other was unthinkable and impractical. On the whole, as long as the military oligarchy wanted the war to continue, the majority of the people would be willing to follow through.

The Nuclear Bombs being dropped finally got the military oligarchy to be willing to give up the fighting, and that is what brought them to the peace table, under the condition that the emperor remain in power. Even after the bombs were dropped, the Emperor's speech never mentioned surrender; just that it was in the best interest of Japan to cease fighting. Had America invaded, the Japanese would have kept on fighting unless given the order to stop. Not only would many American lives have been lost cleaning out all of the fighting forces, everyone in Japan over thirteen was a part of that fighting force. The Japanese people would have been decimated to a point of no return.

Even after having two nuclear weapons dropped on them, many of the Japanese military were unwilling to surrender, regardless of the Emperors wishes. In fact the night the Emperor was preparing to surrender a military coup was staged.

It was only the barest of coincidences that prevented this coup from stopping the surrender. Specifically the American military had started giving up that Japan would surrender at all and decided to bomb the last stores of heating oil in the country (with winter approaching).

The flight flew over Tokyo and the city was blacked out, which stymied the coup. Even after the surrender, many Japanese military leaders chose to kill themselves rather than surrender. As the war ended the Japanese were preparing a massive propaganda campaign to rally civilians to resist the expected invasion.

It's uplifting theme "one hundred million will die in defense of Emperor and Nation." A little cultural note: Ten thousand is the largest number that can be represented by a single character. It is commonly used to represent an indefinitely large number. One hundred million is ten thousand squared, in other words, all will die.

To the last man, woman, and child. Would it have succeeded? Not totally. Japan would not have ceased to exist, not everyone would have had the stomach to sacrifice themselves. But many, many would have. Many did in Okinawa. On top of that, the Japanese military showed it's willingness to make sure civilians had their honor preserved (by killing them) both in Saipan and Okinawa.

It is not the least bit unlikely that they would have done the same--more likely more!--on the Japanese home islands. On top of that the naval embargo and the devastation of the Japanese infrastructure would have condemned millions to death by starvation and exposure during the winter.

President Harry S. Truman dropped the bombs on Nagasaki and Hiroshima for one reason: not to end the war with Japan, but to intimidate Stalin, keep him out of the Pacific war, deny him a share of the peace that we were going to impose on Japan. History shows there was probably not one single general officer in that war who approved of it, and they all went public very quickly to denounce their Commander-in-Chief.

When debating the topic of why the US dropped the atomic bombs on Japan, one must first consider the prelude to the decision. Estimates of U.S. casualties to invade the Japanese home islands were expected to be high; this estimate was based on the stiff Japanese resistance encountered on Okinawa. Naturally the primary motivation to drop the weapons was to end the war as quickly as possible.

Some evidence suggests that the Japanese were seeking to end the war and other evidence suggests that a significant faction in Japan sought to continue the war. While tensions with the Soviet Union would mount in the coming years, the general euphoria of defeating Germany still had not worn off and the Soviet Union still hadn't invaded Manchuria, so clearly the decision to drop the bomb wasn't primarily motivated by a desire to intimidate the Soviets or to prevent the Soviets from seizing ground in China/Korea.

In the end, the only way to judge Truman's decision is to look at the information Truman was presented with. There is no clear evidence to show that Truman knew or had any reason to believe the Japanese were going to surrender, he had witnessed a bloody defense of the home islands and was shown high casualty estimates to invade the Japanese home islands.

However, the second atomic weapon was dropped a short time after Hiroshima, after the Soviets had invaded Manchuria, at a point in time when Japan was in general turmoil, its premier field army (the Kwantung Army was in full retreat) and at a time when Japan's fascist regime was in its death throes.

The decision to drop the second bomb MAY have been premature. However, all things considered, please remember that WW2 was a brutal war, it was a long war, it was a war in which armies of all sides freely bombed civilian populations. Without condoning the killing of civilians, please remember that the cities bombed were NOT Tokyo or Osaka; the decision to bomb Hiroshima and Nagasaki shows at least SOME deference for human life within the larger context of the brutality of WW2.

The answer is not that simple but as Americans we can say that it was because they bombed Pearl Harbor, or that we were doing a favor to everyone because an invasion on the mainland would have cost many people their lives, but that is more reasoning than answers.

If we look at all the facts we could see that America was bombing the Japanese cities with the same types of bombs that the American and British air-forces used against the Germans. Also we see that the Japanese were losing the war greater than thought, there was an American blockade around the island stopping all food and oil from coming into the country, and as we all know humans can not live without food and the Japanese tanks, aircraft's and ships need oil to run so that would have help reduce the resistance from the Japanese. Now I am not saying that I am upset with dropping the bomb because part of me is and part of me isn't.

Because Japan would not put an end to the war. They refused to surrender because they still believed that they could force better terms of surrender if they held out longer. They believed that they could kill over a million U.S. troops if we attempted to invade the Japanese mainland. Estimates varied greatly depending on who ran the numbers.

There was no question that Japan could not be allowed to maintain their military so that they could rebuild just to go after the Pacific again. The Allies had just seen a similar mistake that resulted in the German invasion of Europe and the Allies vowed to not let that happen again. Unconditional surrender was demanded and Japan would not surrender, even after their cities burned and hundreds of thousands died from conventional bombing. Nuclear devices had just been created that were capable of causing unimaginable damage to life and property. Imagine what would have happened back home if the citizens found out that we had a device that could have stopped the war and the President didn't use it and instead almost a million troops were killed in an invasion attempt. Imagine if one of the dead had been YOUR relative, would you be very tolerant that the President didn't use the new weapon? It was an impossible decision.

Hiroshima and Nagasaki Atomic Bombings
Atomic Bombs

What are the names of the planes that dropped the atomic bombs on Hiroshima and Nagasaki?

The names of the planes that dropped the atomic bombs on Hiroshima and Nagasaki are Enola Gay and Bockscar.

On August 6, 1945, at 9:15 AM Tokyo time, a B-29 plane, the "Enola Gay" piloted by Paul W. Tibbets, dropped a uranium atomic bomb, code named "Little Boy" on Hiroshima, Japan's seventh largest city. In minutes, half of the city vanished. According to U.S. estimates, 60,000 to 70,000 people were killed or missing, 140,000 were injured many more were made homeless as a result of the bomb. Deadly radiation reached over 100,000. In the blast, thousands died instantly. The city was unbelievably devastated. Of its 90,000 buildings, over 60,000 were demolished.

The second atomic bomb, named "Fat Man," was dropped on Nagasaki, by Bockscar.

Bockscar is the name of the U. S. Army Air Forces B-29 bomber that dropped the the atomic bomb, "Fat Man," on Nagasaki on August 9, 1945. The name, which is painted on the aircraft is a pun on "boxcar," after the name of the aircraft's commander, Captain Frederick C. Bock. For this mission, however, it was Major Charles Sweeney who flew Bockscar. Some official and unofficial documents have mistakenly called the plane Bock's Car, Bocks Car and Boxcar over the years.

World War 2
Japan in WW2
US in WW2
Atomic Bombs

What year was the first atomic bomb created?

Research in the US and Britain started as early as 1939. Real work started when the US Army was entrusted organising the Manhattan Project, starting in 1942. The first test of a bomb, code named Trinity, was 16 July 1945.

Nuclear Physics
Atomic Bombs

How many atomic bombs will it take to destroy the world?

Answer:The total global nuclear arsenal is about 30,000 nuclear warheads with a destructive capacity of 5,000 megatons (5,000 million tons of TNT).

An air burst (detonating a bomb above the surface) would produce far more damage and death via radioactive fallout than one detonating at ground level.

A single 100 megaton air burst would be enough to cause a nuclear winter and pollute the Earth for many many years. Theoretically, a 100 megaton bomb detonated below ground could produce a massive earthquake and the constant explosions of a full blown nuclear war may also cause numerous earthquakes around the globe. But this would not destroy the world nor all human life.

Globally there are not enough nuclear bombs to completely kill every human. The Tsar Bomb (largest bomb ever detonated) had a fallout of 1000 square kilometres, and was 50 MT. The world is close to 150 million square kilometres, and the human population covers close to 18 million square kilometres.

Therefore to get a rough idea we can say hypothetically that the 5000 megatones of nuclear warheads was 100 Tsar Bombs (the same value in megatons). If these bombs were detonated their total radioactive fallout would cover 100,000 square kilometres.

It may be surprising to hear that this covers less than 1% of the area that the human population covers, which should give a general idea of the miniscule size of impact this would have on the total world's surface. Therefore it can be shown that we do not have the capacity at the moment to destory the world with nuclear warheads.

However, there are factors we have overlooked, which include:

- Tsar Bomb has a very small radioactive fallout in comparison with its megatone value

- Nuclear wardheads can be assumed to target densly populated locations, and

- Nuclear winter which would result in the radioactive fallout

To put curiousty to rest, even if we replaced our Tsar Bomb equation with nuclear warheads that had a higher radioactive yield to fulfill the 5000 megatons gloabl nuclear arsenal we would still not come close to the amount of radioactive fallout required to cover the area the human population covers, let alone destroy the world.

If nuclear warheads were targeted at densly populated locations it would increase the fatalities of a nuclear war, however this would still not wipe out humanity, let alone destory the world.

Nuclear winter can in lamer terms be contrasted with the ice age. The ice age did not destory the world, and did not wipe out all life, therefore neither would nuclear winter. Humanity is extremley resilient, and although many of the world's population die due to starvation if they did not die from the initial nuclear war or radiation, life will find a way.


You forgot to take into account the amount of radiation there would be if more than one detonated at a single time.

My U.S. History teacher told us that if 8 nuclear bombs went off at roughly the same time, it would kill 95% of life in planet Earth.

Nuclear Weapons
Atomic Bombs

How was the atomic bomb detonated?

With conventional explosives to assemble a supercritical mass before it can begin a spontaneous chain reaction, melt and fizzle. Then a neutron source sprays the supercritical mass with a burst of neutrons at the optimal time to trigger a high efficiency chain reaction. The conventional explosives were detonated with electrical exploding wire detonators.

Hiroshima and Nagasaki Atomic Bombings
Atomic Bombs

Were the atomic bombs dropped on Hiroshima and Nagasaki absolutely necessary to ensure the capitulation of Japan?

Well, let's first think of Japan's demands for surrender right before the atomic bombings to get a look at Japan's view.

Imperial Japan demanded the following concessions for their surrender.

  1. They wanted to keep their emperor, and they wanted to keep the home Islands (Honshu, Hokkaido, Kyushu, and Shikoku)
  2. They wanted the Imperial Headquarters to oversee the disarmament and demobilization of their military.
  3. They wanted to have the Japanese government be responsible for punishing war criminals
  4. They wanted no American occupation of Formosa (Taiwan) and Korea.

Contrary to what most people would think, in terms of standard morality and human decency, most of these demands were unreasonable. Keeping the emperor and the home islands were basic points that the American government had long since anticipated and privately accepted before the bombing, but the last 3 points were outright immoral. First off, Japan's high command was literally split between 2 factions: the Emperor and his pro-surrender faction versus the Imperial military (the no-surrender faction). Leaving the disarmament of the military in the hands of people who did NOT want to surrender even at the risk of death was obviously not something the Americans would have liked.

Furthermore, Imperial Japan had committed as many war crimes as the Nazis such as human massacres, human experimentation and torture under Unit 731, and forced conscription of people in their colonies as soldiers. The entire Imperial high command was aware of these atrocities (the emperor himself later acknowledged these), but did nothing to stop it until Japan surrendered. Thus, it can be assumed that allowing the Japanese government to try its own generals and officers for war crimes is in essence a ludicrous idea. It's like asking a unrepentant criminal to be in charge of punishing himself for his crimes: it's just not going to happen.

As for the last concession, allowing Japan to keep Formosa and Korea would not have been a good idea. Just a few months before the atomic bombings, the Imperial Military of Japan massacred over a 100,000 civilians in Manila as a last ditch payback for losing battles. Statistics vary, but given that Japan had killed several hundred thousand Koreans via forced labor during their occupation, allowing Japan to keep the two countries would not be conducive for the well being of human lives. Given the prevalent policies of forced labor, Japan wold have likely used the two colonies for forced labor to recover from its losses in the war, killing hundreds of thousands if not millions more.

Strictly speaking, if the question is to be read as "Would the Japanese have surrendered if the US did not use the Atomic Bomb?" the answer is that Japan would have surrendered, but at a cost of millions of lives all across the pacific, even when you exclude USA casualties. Given that war is inherently immoral, the only determining factor is whether the atomic bombing killed fewer people than the alternative. The atomic bombing worked in this logic: kill 200,000 people to save millions. It was cruel, but also the lesser of the two evils.

As a benchmark, we know the Japanese effectively stopped fighting by August 14th, after the use of the Atomic Bombs.

Note that the Japanese Imperial Council was currently split almost evenly into pro-surrender, and no-surrender-at-any-cost factions. However, the military was almost entirely on the no-surrender side, and it is highly unlikely that they would have obeyed the civilian faction to surrender, even if that faction was the majority. As such, the US faced a situation where the government of Japan would surrender, but the armed forces would continue to fight.

So, what forces the military faction into recognizing defeat? In real life, the use of the atomic bombs allow the Emperor to intervene in the Council, and use the "supernatural" nature of these weapons as a face-saving excuse to allow the military to surrender without suicidal effort. The problem of surrender was exacerbated by poor diplomatic communication between the US and Japan, over what conditions a surrender would be allowed.

The question would be then, what would change the military commander's minds, since the Emperor would need a significant event in order to intercede and break a decision deadlock.

Factually, August and September 1945 were to be rather sparse in terms of scheduled fighting - the IJN was dead, so the would be no naval combat. Japan was saving its forces to fight the expected invasion, scheduled for Oct 1945 by Allied planners. However, there was still plenty of combat in China and the Indochina theater (Burma, Thailand, etc.). Additionally, there are estimates that Allied POW and civilians in occupied areas were dying at a rate of 1,000 per day due to neglect and abuse by Japanese forces. So, each month causes about 30,000 additional deaths, merely by continuing the war, even with no additional combat.

As there is no reason to surrender beforehand, Operation Olympic starts (the invasion of southern Japan). Conservative estimates are for a 3-month campaign, costing 100-200,000 US dead, and 5 times that Japanese. This would be followed by Operation Coronet, the occupation of the rest of Japan, at about the same timeframe, and double the cost.

So, for every month of combat in the Japanese Home Islands, you cost 40,000+ US dead and 250,000+ Japanese dead. There are very likely probabilities that the use of chemical (i.e. poison gas) would have been authorized for use by US forces if the Japanese insisted on fighting as they had at Okinawa or Iwo Jima.

In addition to all this, the continued bombardment of Japanese cities by B-29s was systematically burning Japan to the ground. By Dec 1945, the estimate was that no city of more than 100,000 people would have been less than 50% totally destroyed. This puts over half the Japanese population homeless, and 5-10% of the whole civilian population killed by firebombing (or its aftereffects).

In a similar manner, the total destruction of the Japanese coastal marine and the Japanese railroads meant that food distribution was almost impossible. Widespread famine almost occurred in early 1946 even after the surrender and with the occupying Allied forces there to provide food distribution. With Japan continuing to fight past January 1946, the country would experience a massive famine. A good estimate is 2% of the total population dies EACH MONTH starting in Jan 1946 just from famine.

So, how likely was it that the Council would allow a surrender? It is one of the great imponderables. In my opinion, there is no possibility of a surrender before Olympic finishes. That means, in the best case, a Surrender around Jan 1946. Which means 50,000 KIA and 250,000 WIA on the Allied side, 1,000,000 KIA+WIA on the Japanese side, plus 100,000+ POWs and friendly civilians dead. I would hope that this slaughter would have been enough to stop the war. But, there is a distinct possibility that the Japanese would have effectively chosen ritual suicide for the entire nation. Which means, no surrender until Summer of 1946, at which time, the butchers' bill likely stands at 1,000,000+ Allied (including POWs and civilians in Japanese-occupied nations), and up to 20% of all Japanese dead (i.e. 10 million plus).

So, best case scenario is a balance between the 200,000 casualties of the atomic bomb (all of which are Japanese), vs 1.5 million casualties Operation Olympic would have caused (one-third Allied, two-thirds Japanese). Worst case is at least 15 million casualties after Operation Coronet (15% allied, 85% Japanese).

I would dismiss the notion that President Truman merely wanted to test the destructive power of the atomic bomb. The initial explosion tests on US soil confirmed the destructive force of the bomb. It wasn't a case of the USA having developed just one bomb that could not be wasted on a "test" in the desert. There were several bombs at the ready. The real reason for dropping the first bomb on Hiroshima was to expedite the end of the war with as few casualties as possible. If Truman truly wanted to "punish " the Japanese, he could have ordered the whole arsenal of A-bombs to be dropped on several Japanese cities. He didn't do that but allowed only one to be dropped; then since the Japanese didn't surrender, he ordered a 2nd to go down. Finally the Japanese realized there were possibly many more bombs with the same destructive power and so were brought to their knees.

This wise approach by the 33rd President achieved victory at a lower casualty cost than what might have been had conventional bombing raids/invasion landings taken place

Had the war not ended when it did, the US had production plans, the industrial infrastructure, and the bombers to make and deliver a total of 23 atomic bombs on Japan before the end of 1945. The primary thing limiting production was the Hanford plutonium production reactors, each of the 3 reactors could only produce enough plutonium in a month to make one fatman core.

  1. august: 3 (only 2 were used, third had been built before the surrender and arrived in San Fransisco on august 18, it might have been dropped on Japan around august 25 had the surrender not happened)
  2. september: 3
  3. october: 3
  4. november: 7 (increase in production due to a planned switch to composite plutonium/uranium cores)
  5. december: 7
Note: Truman's actual order was to use the atomic bombs as they became available. This is exactly what was done, Truman did not individually decide whether to use each bomb or when! He let his military field commanders do that. Truman was not a combat action micro-manager like Johnson later was.

Note: Truman could not "have ordered the whole arsenal of A-bombs to be dropped" as no such arsenal existedat the time. The atomic bombs were being dropped on Japan exactly as fast as the factories could make the materials and Los Alamos could prepare the atomic bomb kits for shipment.

War and Military History
Atomic Bombs

Was the atomic bomb a good reason to go to war?

The United States did not go to war over the atomic bomb. We used it to end a war. During WWII there was a race to build the bomb, originally it was going to be used on Germany but Germany fell. Japan however continued to fight on with tenacity Japan showed no signs of wanting to surrender they were conducting many suicide attacks, even to the point of training its civilian citizens to attack invading Americans with sharpened sticks. If America had invaded the main island of japan as was planed the loss of human life (both American and Japanese) would have been astronomical so it was decided to drop the atomic bomb on Japan to let them know we had weapons of mass destruction and we would use them. After the second bomb was dropped Japan surrendered. Although the bombs were dropped on cities and many civilians were killed many many more would have been killed had the United States conducted a conventional invasion. There is also a twist to the this in the Japanese also had an atomic weapons program. Historians dispute the readiness of the Japanese bomb and certainly the German plutonium sent to them was surrendered by the U boat carrying it to the Americans before it reached them. However there is evidence they did have some uranium and credible plans for a bomb. At best case they were a year away at worst case the US beat them to the draw by 11 days, targets included the US Pacific fleet or the West coast cities.

Japan in WW2
Atomic Bombs

What happened after the us dropped atomic bombs on japan?

Japan surrendered and the war was ended

US in WW2
Atomic Bombs

What was the project to build the atomic bomb called?

The United States governments effort to build the atomic bomb was called the Manhattan project.

World War 2
Japan in WW2
US in WW2
Atomic Bombs

Can an atomic bomb cause cancer?

Currently used atomic bombs (and in WW2) use nuclear fission. This means inside the bomb there is a rapid break down of radioactive elements in to stable elements. This releases huge amounts of energy (like in Nuclear Power Plants). It also releases gamma, beta and alpha radiation. These particles can damage your body cells and cause cancer as the damaged cells can multiply and form tumors. The bomb is normally surrounded by the smallest element - Hydrogen. This is because the energy provided by the inner element breaking down (usually Uranium-235) will cause the Hydrogen to undergo Nuclear Fusion. This means the Hydrogen atoms join to form larger atoms - what happens in stars like the Sun. This releases even more energy and dangerous radiation. Being near a dropped bomb is likely to kill you, but going back after the bomb may give you cancer as the radiation will still be present, or from the immediate environment as it has become radioactive/ionized.

This answer refers to fission weapons only (as they wer the type actually used in WW2). The more powerful thermonuclear (fusion) weapons were not developed until the mid 1950s, and while they have similar effects, are vastly more powerful.

Fission weapons have four primary effects:

  1. Blast
  2. Thermal
  3. Prompt Radiation
  4. Fallout

Blast is obvious, and is the same kind of effect that a normal (chemical) weapon of the same equivalent yield.

Thermal is a heat wave (of extraordinary temperature, in the 100s or 1000s of degrees C).

Prompt radiation is Alpha, Beta, and Gamma radiation released by the fission process itself.

In all practical sizes (10kt and up), the lethal distance from the explosion of the blast and thermal effects far exceeds any prompt radiation effects. That is, at any distance where prompt radiation might have an ill effect on a human, they'll be killed by either blast or thermal effects.

Prompt radiation will make certain structures (primarily those made of metal) within the immediate blast radius radioactive. What little remains these structures (after the blast and thermal damage, which is intense) will be radiation dangers for anyone in very close proximity to them afterwards. In the big scheme of things, this is very small, as the remaining wreckage is small, and most will be disposed of quickly.

Fallout is the long-term distribution of radioactive by-products from the fission process. These particles can drift quite a ways from the original target site, though most (75%) will fall within the immediate area.

Fallout is a significant cancer risk. These radioactive particles can deliver intense radiation doses over the course of several weeks. Other particles can deliver much lower doses, but for years. Worse, the chemical properties of these particles make them easy to be absorbed into the food chain, so they'll contaminate most living things in the fallout zone, possibly for years or decades.

The exact danger depends on a whole range of characteristics (type of weapon, type of detonation, nature of the target, winds, weather, topography, local climate, etc.) - so much so, that it's impossible to accurate predict statistics on the dangers.

In the case of the two uses of atomic bombs on actual human beings, the amount of cancer caused is hotly debated. The combined immediate death tolls of the two cities is around 100,000. Another 100,000 died in the following month due to burns, trauma, radiation sickness, and the results of destruction of social supporting institutions. Over the following decades, somewhere between 10,000 and 50,000 cases of cancer can possibly be attributed to long-term radiation exposure effects, but it's impossible to be sure.

Japan in WW2
Albert Einstein
Atomic Bombs

What were the names of the two atomic bombs that Albert Einstein made?

Einstein did not personally make any atomic bombs, nor was he particularly involved in the Manhattan Project. (He couldn't obtain the necessary security clearance. and scientists in the project were actually forbidden from consulting with him about it.)

The names of the first two bombs were "the gadget" and "Little Boy." The gadget was the one used in the Trinity test firing, and was a test of the design used for the third bomb, "Fat Man" (Little Boy was considered a simple enough design to not need a test firing, but the gadget and Fat Man were more complicated.)

Hiroshima and Nagasaki Atomic Bombings
Atomic Bombs

When did America drop the atomic bombs on Japan?

The first atomic bomb was dropped on August 6, 1945 at Hiroshima. Three days later, the second atomic bomb was dropped on August 9, 1945 at Nagasaki.

US in WW2
Atomic Bombs

What was the atomic bomb capable of doing?

Destroying an entire city in seconds

World War 2
Japan in WW2
US in WW2
Atomic Bombs

Did the atomic bomb start an arms race?

yes everyone wanted a stronger bomb so they could threaten their enemies.

World War 2
Japan in WW2
US in WW2
Atomic Bombs

Why are Modern thermonuclear weapons are different from the atomic bombs used in World War 2?

Modern thermonuclear weapons ("Hydrogen bombs") use multiple stages to create their destructive power. It is known that most modern weapons use a fission trigger (basically a small atomic bomb) to create the energy to initiate fusion in the second stage of the weapon (the fusion stage -- the exact mechanism is classified but it could have something to do with ablation of the secondary tamper and radiation implosion) and thereby create a very large and potentially much more destructive explosion.

The two atomic bombs used by the US against Japan were single-stage weapons, but the technology used between the two was different. The yields of those weapons were in the 11 - 15 kiloton range. Modern thermonuclear weapons have higher yields in the hundreds of kilotons.

Additionally, the weapons used against Japan were very large by today's standard (especially for the small yield they had). Modern 150 kiloton thermonuclear warheads can be as small as around three feet long by maybe a 18 inches wide (these are only estimates in size) including the reentry vehicle.

Besides the technical differences outlined above, there is another, more important difference: scale.

The atomic bombs used on Japan had a yield of less than 25kT. Modern thermonuclear weapons generally start at around 350kT, and many are in the 1MT range. Additionally, thermonuclear weapons have very little upper limit: it's actually possible to build a thermonuclear device with a yield over 100MT, though they're impractical as a weapon.

Relative destructive power of a nuclear weapon is measured in Equivalent Megatons (EMT), as yield does not linearly increase destruction. The 2/3rds root of a weapon's yield (as expressed in MT) gives the EMT. I.e. EMT = MT2/3 Thus, a 1MT weapon has 1EMT of damage. A 27MT weapon is 9 EMT. And a 0.25MT (250kt) weapon does 0.4 EMT.

What all this math means is that modern thermonuclear weapons of around 1MT are roughly 12 times as destructive as those dropped on Hiroshima and Nagasaki. They also produce radically higher secondary effects, such as massive firestorms in the surrounding forests, far higher dust injection into the stratosphere, and a whole host of environmental effects that were minimally felt from the low-yield WW2 weapons.

Put it another way: the WW2 bombs were like being run over by a car at 40mph. They could cause horrific damage, but highly localized, and, ultimately, rather survivable for a country and total population. Thermonuclear weapons are like having your neighborhood crashed into by a 747 at 500mph - vastly larger effects, including large-scale environmental effects far outside the immediate target area.

WW2-size atomic weapon threatens cities with destruction. An equivalent number of thermonuclear weapons threaten entire countries with destruction, including those far outside areas actually hit with the weapons.

Albert Einstein
Atomic Bombs

Why did albert einstein help invent the atomic bomb?

No, he was a pacifist and worked on no war projects. His only involvement with the atomic bomb was to sign a letter to FDR that Leo Szilard had written, warning that the Nazis might make one first.

The atomic bomb was not invented in the US or by Einstein, it was invented in London, England in 1933 by one of Einstein's friends - Leo Szilard while crossing a street and patented by him in 1934. What Szilard wanted when he invented the atomic bomb was only to provide a better way to transmute elements than was then available, but at the same time he did recognize its potential for a large energy release which might make it useful as a weapon.

However it took 12 more years, many scientists & engineers & technicians, and an enormous investment in new industrial infrastructure before the first atomic bombs could be built.

World War 2
Hiroshima and Nagasaki Atomic Bombings
Atomic Bombs

How did the use of atomic bombs impact the outcome of World War 2?

They impacted the war by making the Japanese surrender almost immediately after they were dropped on Hiroshima and Nagasaki.

Nuclear Weapons
Atomic Bombs

What is an atomic bomb?

There are two basic types of nuclear weapons: those that get most of their energy from nuclear fissionreactions alone, and those that use fission reactions to begin nuclear fusion reactions that produce a huge explosive output.

The fission type bombs are called atomic bombs or atom bombs (abbreviated as A-bombs).

In fission weapons, a mass enriched uranium or plutonium is brought to a supercritical mass (the
amount of material needed to start a nuclear chain reaction) either by shooting one piece
of sub-critical material into another (the "gun" method) or by squeezing together sub-critical spheres
by using chemical explosives (the "implosion" method).

The fission way can be only be used if the fissile material is plutonium.

A major challenge in all nuclear weapon designs is to make sure that a very large fraction of the fuel is consumed before the weapon destroys itself.

The amount of energy released by fission bombs can range from the equivalent of just under
a ton of TNT, to upwards of 500,000 tons (500 kilotons) of TNT.

All fission reactions produce radioactive remains. Many fission products are either highly radioactive (but short-lived) or moderately radioactive (but long-lived). That makes them a form of radioactive contamination if not fully contained.

Fission products are the principal radioactive component of nuclear fallout.

The most commonly used fissile materials for nuclear weapons have been uranium-235 and plutonium-239. Less commonly used has been uranium-233. Neptunium-237 and some isotopes of americium may be usable.

Albert Einstein
Atomic Bombs

How did albert einstein make the atomic bomb?

No, he was a pacifist and worked on no war projects. His only involvement with the atomic bomb was to sign a letter to FDR that Leo Szilard had written, warning that the Nazis might make one first.

The atomic bomb was not invented in the US, it was invented in London, England in 1933 by Leo Szilard while crossing a street and patented by him in 1934. However it took 12 more years, many scientists & engineers & technicians, and an enormous investment in new industrial infrastructure before the first atomic bombs could be built.


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