I am happy to inform you that my blog has now gone critical. Yeh.
Going critical is a term that is used in the nuclear power industry, to mean initiating a controlled, self-sustaining chain reaction.
When a neutron is made to hit a Uranium-235 atom, the atom splits into two lighter elements, Barium and Krypton, and gives off three neutrons, which in turn zoom off every which way they can. They might hit the reactor wall and just get absorbed by it or they might hit some other part of the reactor machinery and the same thing happens.
But if those three neutrons happen to hit three more Uranium atoms instead, then they end up releasing nine new neutrons. As this goes on and more and more neutrons keep hitting more and more Uranium atoms, at a certain point the process goes out of control and releases a humongous explosion. All this takes just nanoseconds actually and the process is called uncontrolled nuclear fission.
The good thing is that this runaway reaction can’t happen unless the Uranium has a minimum critical mass that would ensure that enough neutrons hit enough U-235 atoms. The critical mass depends upon the purity and shape of the radioactive material and in the case of U-235, it would be a 99.9% pure sphere of roughly 52 kgs weight. If you happen to be holding a 52 kg pure U-235 ball in your hand, you are likely to be vaporized in the next picosecond.
By the same argument, if the U-235 has a mass below critical mass, or if there is a way by which you can slow down the neutrons, the lump will simply glow hot and remain that way for a long long time, the heat so intense that it can boil tons and tons of water and produce steam that will then run a steam turbine and generate electricity. This process is a self-sustaining chain reaction that has been artificially harnessed for peaceful purposes.
My blog now resembles a nuclear reactor that has gone critical. Whether I write any new posts or not, my blog gets hits. I haven’t written anything for days but still there are good, honest, God-fearing folk the world over, who are visiting my blog and reading my posts. Thank you for sustaining this fission reaction.
The first examples of unsustained nuclear fission reaction were actually an experiment and the only ones carried out deliberately on live civilian targets – the bombing of Hiroshima and Nagasaki.
Here was a new weapon that had the potential to kill hundreds of thousands but it’s destructive effect was as yet untested. And there was a pretext – Pearl Harbor and the decades of atrocities on the Chinese, the Koreans and the Philipinos. One thing was certain – no one would be sorry. If 68 civilians were killed at Pearl Harbor, then of course 68000 civilians must die at Hiroshima – that was the simple logic. (Actually 166,000 were killed at Hiroshima – now we know how much of an over-achiever America really is).
Japan meanwhile was teetering on the brink of collapse, gravely wounded, stripped of munitions and supplies, it’s air forces and navy decimated and it’s citizens virtually starving from the blockades, Japan was a pathetic caricature of it’s former imperial grandeur. It’s only ally, Nazi Germany, had already capitulated and it’s surrender had been accepted hurriedly and ceremoniously. At a schoolhouse in Reims, the wine flowed as the ‘instrument’ of surrender was signed in all civility over toasts and cheeses, with Nazi Generaloberst Alfred Jodl made to feel as more like a dinner guest than a murderer being brought to justice. All goody goody and nice.
The Japanese did not have the same skin pigmentation as the Germans and the Americans unfortunately. The end came quite differently for them. Japan knew that the game was up. It was desperate to make peace in a way that would let it retain a vestige of honor. Japan was under siege on all sides. Japan was screaming to surrender.
But alas, Japan had already been chosen as the lab and the experiments had to be carried out. Bombing Hiroshima and Nagasaki was a perfect set-up. It was the only time in history when the wholesale slaughter of innocent men, women and children was dressed up to feel and seem good and holy. A similar set-up had been available in Nazi Germany and the very same bombings could as well have been carried out on Germany but remember the skin color thingy? Can you imagine a white guy vaporizing another white guy? I can’t.
In the context of Hiroshima and Nagasaki, the targets had been carefully chosen. A number of American experts in various fields assisted in the study. These included mathematicians, theoretical physicists, experts on the blast effects of bombs and meteorologists. The considerations included the range of the aircraft which would carry the bombs, weather conditions, terrain, etc.
Even if one concedes that maybe they were justified, the nicknames that the Americans had given to the two bombs – Little Boy (for Hiroshima) and Fat Man (for Nagasaki), conveyed the flagrant frivolity with which the Americans viewed the mass slaughter of innocent men, women and children, folk who just happened to be at the wrong place at the wrong time. Little Boy, Fat Man – names that would make an obese American gorging on a double mac in a McDonalds titter in amusement.
In the planning of the Hiroshima and Nagasaki bombings, one primary and two secondary targets were chosen. These six cities had certain attributes in common between them – All were mid-sized cities with populations in several hundreds of thousands and built-up downtown cores that were at least 4 sq. kms in radius. They all had large reinforced concrete constructions that were designed to withstand earthquakes of up to 7.5 in the Richter Scale. The weather around them was known to be reasonably stable and predictable. They were all situated on flat terrains devoid of major hills or mountain ranges and therefore the blast and the shock waves as well as the radioactive fallout would not get boxed in but spread unimpeded, causing the maximum damage.
Except for Hiroshima, none of the others were militarily strategic. The aim was not to disable the Japanese military apparatus. The once formidable Japanese military machine was already finished. Chronic fuel shortage and saturation bombing had rendered their air force and airfields almost useless. By the spring of 1945, all that was left was fanatical nationalism that spurred the Japanese ground forces to keep fighting till the bitter end.
The goal of the Americans was to terrorize and demoralize. The knowledge that your enemy has the power to annihilate you and you can do nothing to stop him, can sap the will to go on fighting. You might have hundreds of suicidal kamikaze loonies and scores of stoic infantry soldier who are ready to fall under a hail of bullets in the name of honor, but not all your other compatriots wish to die for their country needlessly.
Once they were selected as possible targets back in 1942 both, Hiroshima and Nagasaki were left untouched by the allies as conventional bombing targets, so that the damage caused solely due Little Boy and Fat Man could be assessed accurately and the data analyzed for future weapons development. So, both cities were largely intact, bustling with activity, when the bombs exploded 1800 feet above the ground.
Little Boy had an yield of 15 Kilotons and Fat Man – 21 Kilotons.
The two B61s that were enroute to Byblos on the Aida, each had the power to produce 170 Kilotons. If air-burst denoted simultaneously over the right targets, Israel could cease to exist.