Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: annie123 on 02/09/2015 04:49:20
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When the h bomb went off in Japan some bodies were vaporized leaving only a shadow on a wall. What happened to the molecules making the bodies? Does vaporized mean changed into water droplets as in ordinary language? or do the bodies literally disappear with nothing remaining?
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When the h bomb went off in Japan some bodies were vaporized leaving only a shadow on a wall. What happened to the molecules making the bodies? Does vaporized mean changed into water droplets as in ordinary language? or do the bodies literally disappear with nothing remaining?
The scatter into the atmosphere as a gas of atoms of a plasma of nuclei.
To vaporize an element or compound is a phase transition from the liquid phase to vapor. A vapor is a substance in the gas phase at a temperature lower than its critical point.
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They weren't H bombs. But the bodies were indeed dispersed into the atmosphere by evaporation or combustion.
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In the Nagasaki Atomic Bomb Museum, there are photographs and samples of shadows etched into concrete and wood by people, trees and bridge railings.
The initial flash was very intense; it changed the color of a stone or concrete bridge. I recall a photo of US military personnel working out the location of the fireball by looking at the angle and length of the shadows of the railing posts (it seemed to be at around 45° elevation). If this were a wooden bridge, it probably would have been incinerated by the ensuing fire.
More distant sites showed outlines of trees or fenceposts on the side of houses, at a more horizontal angle. These must have been distant enough that the building did not actually catch fire, but it was scorched by the initial heat. The fireball cools rapidly as it expands, so the initial heat does not last very long.
There was another photo of a stone step; the mark burnt into the step is thought to be from a person sitting on the step at the time of the flash.
But I do not expect that the person would have actually been evaporated. From other gruesome images, bodies quite close to the hypocentre were badly scorched, but still had flesh and bones. This is because the human body is mostly water, which has a very high specific heat.
So the outer layer of the bodies would have been carbonised (with products like carbon dioxide and steam, plus oxides of nitrogen & sulphur). But the bulk of the body would have undergone bacterial decomposition, which mostly produces CO2, but also more complex hydrocarbons.
This museum is a very sobering experience - it certainly encourages nuclear disarmament.
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Having a look on my hard disk revealed the following image (apologies for the reflections in the glass)...
In this case, a lookout 4.4km south of the hypocenter was exposed to the flash of the atomic bomb. Tar on the building exposed directly to the flash burned and disappeared, but the tar in the shadow of the soldier and his ladder remained (dark shadow).
The hot fireball rises as it cools. But it did not rise very far before it cooled, or the horizontal rungs would not have cast such a distinct shadow.
To the right of the building, it looks like a tree is still standing, with twigs but very few leaves.
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On a related topic, I just listened to a podcast from 40 years ago(!), where William Epstein of the UN spoke about the efforts up to that time by the US & Russia to limit the growth of nuclear weapons.
He commented that the best agreement they could achieve was to set targets on the number of nuclear weapons that were higher than either side held at the time.
This irresponsible attitude on both sides resulted in a spate of nuclear proliferation which today sees many countries with nuclear weapons capability. Imitation is the sincerest form of flattery.
Fortunately, some old launchers & warheads are now being recycled for more peaceful purposes (like launching space probes and fuel for commercial power reactors).
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Countries with atom bombs such as North Korea and Pakistan don't get invaded by the Americans that's why they want them.
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Countries with atom bombs such as North Korea and Pakistan don't get invaded by the Americans that's why they want them.
Peaceful countries, living in harmony with the rest of world, are not invaded by Americans..
Bomb is not needed.
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Countries with atom bombs such as North Korea and Pakistan don't get invaded by the Americans that's why they want them.
Peaceful countries, living in harmony with the rest of world, are not invaded by Americans..
Bomb is not needed.
In general that is true, but tell that to Colombia. When they denied the US permission to build a canal across their country to connect the Atlantic and Pacific, we (the US) helped a revolt take place in the Northern part of their country, and voila! Panama came to be. The Panamanians were very quick to grant permission.
https://en.wikipedia.org/wiki/History_of_the_Panama_Canal#The_United_States_and_the_canal