Harold Agnew carrying the plutonium core of the Nagasaki Fat Man bomb, 1945

Somewhat strange picture and not very exciting unless you are aware of the details. Harold Agnew's smile leaves the audience disconnected from the reality of the situation. That box is the direct cause of the deaths of about 70,000 people. That little box will change the course of history, and he's holding it like it's his lunch.

The weirdest thing here is that a whole bunch of scientists had pictures of themselves posing with the plutonium core. He was proud of his invention, and the fact that he was making history. For a lot of reasons, they had no second thoughts about what they were planning to do.

Harold Agnew watched the atomic bomb be completed from start to finish. As a member of Enrico Fermi's research team at the University of Chicago in 1942, Agnew witnessed the first sustained nuclear chain reaction, Chicago Pile-1. He worked in the Department of Experimental Physics at Los Alamos from 1943 to 1945.

When the Trinity test was being conducted, Agnew was already en route to Tinian Island in the Pacific as part of Project Alberta, the group responsible for the final bomb assembly.

He flew as a scientific observer on a B-29 bomber for the Hiroshima bombing mission, which measures the size of the shock wave to determine the bomb's power. He also filmed the explosion with a movie camera.

The plutonium core (box) in Fat Man weighed 6.2 kg, or about 14 lb, with the crater 9 cm (4 in) across. And only a fifth of it, a little over 1 kg (2 lb), undergoes a fission reaction. And of that only one gram (1/30th of an ounce) is converted into explosive energy equivalent to 21,000 tons of TNT.

Fat Man was the codename for the type of atomic bomb that was detonated by the United States on the Japanese city of Nagasaki on August 9, 1945. It was the second of only two nuclear weapons used in war, the first being Little Boy, and its explosion marked the third man-made nuclear explosion in history.

But what if he accidentally drops it?

In order to explode, the core has to reach critical mass. In a uranium bomb, the fragments are kept separate to remain "subcritical", so that each piece cannot individually initiate a chain reaction. The explosion begins with a bullet fired at the bottom of a gun barrel like a bullet.

The same style of box was used for the first three cores: Trinity Corps, Fat Man Corps and Demon Corps. It was made of magnesium to dissipate heat and not reflect neutrons. The box was safe to drop; It would have just bounced (and yes, they tested it!)

The photo above was kept by Harold Agnew as a souvenir, but the FBI had a problem with it. As Agnew later told the story: "I was in post-war Chicago in 1946. The FBI came and said they believed I had some secret photos. They looked through my photos and found nothing. Then I said like a fool: Maybe it's secret. They wanted to know what that thing was. I told them and they said it must be secret and wanted the picture. I wanted the picture so they agreed if I'd thing' so I could keep the slide".

If Japan had not surrendered unconditionally, their war with the Soviet Union could have been much bloodier than before. The US in Japan at the end of the war. Their presence may have been the only thing that saved them from the invasion of the Soviet Union. America had three options:

Drop the bomb and wait for the unconditional surrender.

Accept a conditional surrender and let Japan fight the Soviet Union (a certain defeat that would have resulted in more power for the Soviet Union).

Invade mainland Japan and force an unconditional surrender at the cost of 1,000,000+ casualties per side.

There are many theories, many of which are advanced by American opponents, as to why the US dropped the bomb other than a "quick end to the war" or that the Japanese surrendered for any reason but the bombs were dropped.

The truth is complicated. The Soviet Union, by treaty, declared war on Japan and began invading the occupied territories on 9 August, following Hiroshima and before Nagasaki.

In July 1945, less than a month after the atomic bomb was dropped, the U.S. The U.S. stopped internal Japanese communications (from Foreign Minister Togo), stating that Japan would never accept an unconditional surrender and would instead fight to the bitter end.

Further confusing matters, the Japanese published two justifications for surrender, one saying bombs, the other claiming Soviet declarations. If anything, it is an indicator that both were the cause. The truth is that the US most likely dropped the bombs as part of a desire to end the war with Japan. Any message for the Soviet Union could be seen as a bonus.

In the words of Dwight Eisenhower:

War Secretary Stimson, visiting my headquarters in Germany, informed me that our government was preparing to drop an atomic bomb on Japan. I was one of those who felt that there were many solid reasons to question the wisdom of such an act...

During his recitation of the relevant facts, I was conscious of a sense of depression and so I voiced him for my grave apprehensions, based first on my belief that Japan was already defeated and that the bombings were completely unnecessary, And second because I thought that our country should avoid shocking world opinion by the use of a weapon whose employment, I thought, is no longer mandatory as a measure to save American lives. It was my belief that Japan, at that very moment, was looking for some way to surrender with minimal loss of 'face'.