# Were people really vapourised at Hiroshima/Nagasaki? **URL:** \ **Category:** Factual Questions\ **Created:** [August 18, 2016, 4:11pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179 "2016-08-18T16:11:08Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [August 19, 2016, 5:19pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/41 "2016-08-19T17:19:56Z")
> [@TriPolar](#): > > All the water in your body would vaporize, and that would blow every part of you that didn’t vaporize into smithereens. What do you base this on? I assume you don’t have personal experience of this phenomenon, so where did you read this? –Mark ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [August 19, 2016, 5:49pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/42 "2016-08-19T17:49:41Z")
> [@markn\_1](#): > > What do you base this on? I assume you don’t have personal experience of this phenomenon, so where did you read this? > > –Mark Sorry, I thought I had quoted something above and following up on that. \*If \*all of the water in your body turned to steam _I think_ you would turned to smithereens. ---
**Author:** ![Chimera](https://avatars.discourse-cdn.com/v4/letter/c/8e8cbc/32.png) [@Chimera](https://boards.straightdope.com/u/Chimera)\ **Post date:** [August 19, 2016, 5:56pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/43 "2016-08-19T17:56:51Z")
Eh, the temperature alone isn’t the issue. The BLAST itself has a rather large pressure wave. ---
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [August 19, 2016, 6:03pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/44 "2016-08-19T18:03:08Z")
> [@Magiver](#): > > The first wave hit the nearby Herculaneum with temperatures as high as 500 degrees Celsius. The searing heat was enough to boil the brains and instantly vaporise the flesh of its victims so that only blackened skeletons remained. Am I correct in that an oven set to 250 Celsius will still take several minutes to reduce a steak to blackened stuff? Why would 500 degrees Celsius “instantly” vaporize flesh? ---
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [August 19, 2016, 6:03pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/45 "2016-08-19T18:03:25Z")
From what I understand, the shadows were the result of the initial flash of the explosion, not the subsequent effects like the fireball or blast wave. The people who left those shadows may not have been atomized or even killed by that flash. The flash created all the shadows in that one instant and then it’s possible that the various people were then incinerated in the heat and/or destroyed by the blast wave, depending on the distance from the hypocenter or other local conditions like intervening materials. There are anecdotes of people having one side of their body charred by the flash but otherwise surviving the bomb. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [August 19, 2016, 6:28pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/46 "2016-08-19T18:28:49Z")
> [@HMS\_Irruncible](#): > > The weapon detonated at 1,870 feet, the fireball is documented as being 1,200 feet wide, and at about 6000C degrees at its surface. So it makes sense for the air temperature at the hypocenter to be about 3000C. But that’s like a 3000C oven. But air transfers heat slowly, so that wouldn’t cause vaporization. The thermal effects are mainly going to come from the radiation pulse. That is significant, but the concept doesn’t transfer directly to the gas torches that you want to compare them to. The initial burst is 100 million degrees. It is literally the sun at 1/3 of a mile away. It’s enough energy to flatten a city to nothing. It vaporized the roof on the exhibition building. Why you think 3000C from a nuclear device is somehow different than 3000C from the tip of a torch is something that needs to be explained. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [August 19, 2016, 6:48pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/47 "2016-08-19T18:48:53Z")
Let’s step through this. > [@Magiver](#): > > The initial burst is 100 million degrees. Not relevant. All that energy dissipates quickly, most of it X-rays heating the surrounding air into an incandescent fireball. > [@](#): > > It is literally the sun at 1/3 of a mile away. Just a few milliseconds, though. > [@](#): > > It’s enough energy to flatten a city to nothing. Little Boy flattened a few blocks of the city. Most of the city was destroyed by the ensuing fire. > [@](#): > > It vaporized the roof on the exhibition building. Overpressure effects. > [@](#): > > Why you think 3000C from a nuclear device is somehow different than 3000C from the tip of a torch is something that needs to be explained. Because a 3000C oven transfers heat differently than a blowtorch. I know this because I’ve processed samples in a muffle furnace, but you can demonstrate it yourself at home. And even a blowtorch isn’t the holy finger of God. Hit some spare ribs with the hottest torch you can find for 1 second, and see what happens. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [August 19, 2016, 7:00pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/48 "2016-08-19T19:00:57Z")
> [@HMS\_Irruncible](#): > > Because a 3000C oven transfers heat differently than a blowtorch. I know this because I’ve processed samples in a muffle furnace, but you can demonstrate it yourself at home. And even a blowtorch isn’t the holy finger of God. Hit some spare ribs with the hottest torch you can find for 1 second, and see what happens. ^This. Temperature alone isn’t a good metric for estimating thermal effects. Put your hand in a 400 F oven for 5 seconds and it will feel warm. Put your hand in a 212 F pot of boiling water for 5 seconds and you’ll have third degree burns. –Mark ---
**Author:** ![Malthus](https://avatars.discourse-cdn.com/v4/letter/m/85f322/32.png) [@Malthus](https://boards.straightdope.com/u/Malthus)\ **Post date:** [August 19, 2016, 7:02pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/49 "2016-08-19T19:02:53Z")
It’s an interesting question. This very issue was tackled by a newpaper published by Japanese teenagers: [http://www.hiroshimapeacemedia.jp/hiroshima-koku/en/exploration/index\_20090309.html](http://www.hiroshimapeacemedia.jp/hiroshima-koku/en/exploration/index_20090309.html) The consensus: no “vaporization” of bodies; but they may have been “carbonized” to burn bones & gristle and then the remains blasted away by the shock wave, leading to the notion that they had simply “vanished”. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [August 19, 2016, 8:04pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/50 "2016-08-19T20:04:01Z")
> [@HMS\_Irruncible](#): > > Overpressure effects. The people who were not made of metal also disappeared. > [@HMS\_Irruncible](#): > > Because a 3000C oven transfers heat differently than a blowtorch. I know this because I’ve processed samples in a muffle furnace, but you can demonstrate it yourself at home. And even a blowtorch isn’t the holy finger of God. Hit some spare ribs with the hottest torch you can find for 1 second, and see what happens. Hit some spare ribs with an acetylene torch the size of the ribs and see what happens. Aluminum melts at 993k. that’s a third of the temperature people were exposed to. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [August 19, 2016, 8:32pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/51 "2016-08-19T20:32:02Z")
> [@Hypno-Toad](#): > > From what I understand, the shadows were the result of the initial flash of the explosion, not the subsequent effects like the fireball or blast wave. The people who left those shadows may not have been atomized or even killed by that flash. The flash created all the shadows in that one instant and then it’s possible that the various people were then incinerated in the heat and/or destroyed by the blast wave, depending on the distance from the hypocenter or other local conditions like intervening materials. There are anecdotes of people having one side of their body charred by the flash but otherwise surviving the bomb. This. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [August 19, 2016, 8:41pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/52 "2016-08-19T20:41:24Z")
> [@Magiver](#): > > The people who were not made of metal also disappeared. Not sure what point this supports, but again, blast effects. > [@](#): > > Hit some spare ribs with an acetylene torch the size of the ribs and see what happens. The same thing will happen. A bigger flame doesn’t mean heat gets transferred faster. > [@](#): > > Aluminum melts at 993k. that’s a third of the temperature people were exposed to. Just because you a block of aluminum in an oven at 993K doesn’t mean it’s instantly going to melt, and it’s certainly not going to vaporize. Again we’re talking about heat transfer in air. Air is not a good thermal conductor. That’s why you can safely put your hand in a 500F oven to pull out the ribs, but you wouldn’t want to touch a 500F piece of metal or water at the boiling point. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [August 19, 2016, 8:42pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/53 "2016-08-19T20:42:40Z")
> [@Magiver](#): > > Hit some spare ribs with an acetylene torch the size of the ribs and see what happens. What are you claiming would happen, that the meat would instantly vaporize? If that were true, then hitting the ribs with an ordinary acetylene torch would instantly vaporize the part of the ribs directly touched by the torch. > [@Magiver](#): > > Aluminum melts at 993k. that’s a third of the temperature people were exposed to. That’s a good point, which refutes your argument. Aluminum melts at 993 K. Steel melts at about 1650 K, both much lower than the temperatures reached at the bomb site. Yet there are pieces of steel still sitting there, not reduced to molten puddles. Why? Because the heat didn’t last long enough to melt them, just as it didn’t last long enough to reduce the bodies to ash. –Mark ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [August 19, 2016, 9:29pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/54 "2016-08-19T21:29:17Z")
There was a flash _and_ a fireball. The fireball doesn’t last milliseconds. [Here](http://www.newyorker.com/magazine/1946/08/31/hiroshima) is John Hersey’s original New Yorker article. (Some changes were made for the book. Alas it is not available as an ebook.) “Others found that mica, of which the melting point is 900° C., had fused on granite gravestones three hundred and eighty yards from the center; that telephone poles of Cryptomeria japonica, whose carbonization temperature is 240° C., had been charred at forty-four hundred yards from the center; and that the surface of gray clay tiles of the type used in Hiroshima, whose melting point is 1,300° C., had dissolved at six hundred yards; and, after examining other significant ashes and melted bits, they concluded that the bomb’s heat on the ground at the center must have been 6,000° C.” If you were unsheltered very near ground zero, there was nothing left but ash. But the heat dropped off quite rapidly with distance. The surfaces of clay tiles exposed to 1,300C temp for milliseconds wouldn’t have dissolved. If it’s any consolation to most vaporized victims, they would have been immediately blasted with a shock wave that would have killed them just as well. ---
**Author:** ![Simple\_Mind](https://avatars.discourse-cdn.com/v4/letter/s/7cd45c/32.png) [@Simple\_Mind](https://boards.straightdope.com/u/Simple_Mind)\ **Post date:** [August 20, 2016, 12:21am UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/55 "2016-08-20T00:21:41Z")
I am quite amazed that this morbid thread is still on, I am also wondering what would be the result if one would translate all of it into Japanese and have it posted on a Japanese site… Remember, NO Americans got “vaporized”… Peace ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [August 20, 2016, 12:30am UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/56 "2016-08-20T00:30:42Z")
> [@Simple\_Mind](#): > > I am quite amazed that this morbid thread is still on, I am also wondering what would be the result if one would translate all of it into Japanese and have it posted on a Japanese site… > Remember, NO Americans got “vaporized”… > > Peace There were 20 Dutch, British and American POW’s that died from the bombings. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [August 20, 2016, 12:47am UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/57 "2016-08-20T00:47:48Z")
> [@Simple\_Mind](#): > > NO Americans got “vaporized”… > > Peace Some POWs [got et](http://www.telegraph.co.uk/news/worldnews/asia/japan/1445167/George-Bushs-comrades-eaten-by-their-Japanese-PoW-guards.html). Peace ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [August 20, 2016, 3:32am UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/58 "2016-08-20T03:32:29Z")
I wonder how much x-ray energy was converted to heat inside the bodies of victims right at ground zero. ---
**Author:** ![Atomic\_Alex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atomic_alex/32/175_2.png) [@Atomic\_Alex](https://boards.straightdope.com/u/Atomic_Alex)\ **Post date:** [August 20, 2016, 7:48am UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/59 "2016-08-20T07:48:55Z")
> [@Simple\_Mind](#): > > I am quite amazed that this morbid thread is still on, I am also wondering what would be the result if one would translate all of it into Japanese and have it posted on a Japanese site… > Remember, NO Americans got “vaporized”… > > Peace And yet. > [@Malthus](#): > > This very issue was tackled by a newpaper published by Japanese teenagers: > > [Peace Newspaper produced by Japanese teenagers: Peace Seeds:Q & A about Hiroshima/the atomic-bomb [Is it true that human beings vanished in the bomb's heat?]](http://www.hiroshimapeacemedia.jp/hiroshima-koku/en/exploration/index_20090309.html) > > The consensus: no “vaporization” of bodies; but they may have been “carbonized” to burn bones & gristle and then the remains blasted away by the shock wave, leading to the notion that they had simply “vanished”. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [August 20, 2016, 3:40pm UTC](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179/60 "2016-08-20T15:40:39Z")
> [@beowulff](#): > > I wonder how much x-ray energy was converted to heat inside the bodies of victims right at ground zero. If you look at[videos of structures](https://www.youtube.com/watch?v=RqyBzXYZPoM)used at test sites the wooden ones begin smoking before the shockwave hits them and blows them apart. It’s s not just X-rays. There is a substantial release of infrared heat released. [Previous page](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179.md?page=2) [Next page](https://boards.straightdope.com/t/were-people-really-vapourised-at-hiroshima-nagasaki/763179.md?page=4)