Declassified effects of nuclear weapons and other threats: minimizing weapons effects on civilians

Can Britain and America prevail over an alliance of Russia, China, Iran and North Korea in WWIII? American sanctions on Japan in 1940 led to Pearl Harbor on 7 December 1941, so beware of the lessons of history Mr President, and get civil defense

Friday, April 07, 2006

Ignition of fires by thermal radiation exposure



The 1950 U. S. Department of Defense book The Effects of Atomic Weapons stated on page 212: “It has been estimated ... that the physical damage to buildings, etc., equivalent to that at Hiroshima could be produced by approximately 325 tons of high explosive and about 1,000 tons of incendiary bombs.”


J. Bracciaventi and F. DeBold, Critical Radiant Exposures for Persistent Ignition of Cellulosic Target Complex Materials, Naval Material Lab., Brooklyn, report AD-249476, DASA-1194, July 1960:

"Winds up to 10 mph caused differences in radiant exposures for ignition up to 50%, and conditioning at relative humidities from 20 to 100% changed ignition exposures by 70%."


“Measurements were made to determine the irradiance and time necessary to produce glow and flaming ignition in ponderosa pine, Douglas fir, and maple. ... It was concluded that for sound solid woods of a normal moisture content, it is almost impossible to start continued ignition with nuclear weapons of a size less than about 100 Mt at a distance where blast damage would not be severe.”

- F. W. Brown, III, Ignition of Thick Wood Specimens by High-Temperature Thermal Radiation, Naval Civil Engineering Laboratory, California, 1965, AD0475535.


The 1957 U. S. Department of Defense book The Effects of Nuclear Weapons stated on page 307 that only 2 and 4 cal/cm2 were required by 20 kt and 10 Mt nuclear weapons, respectively, to ignite shredded newspaper, and on page 308 it stated that only 4 and 9 cal/cm2 were required by 20 kt and 10 Mt nuclear weapons, respectively, to ignite dry rotted wood. However, on pages 322-3 it stated: “Definite evidence was obtained from Japanese observers that the thermal radiation caused thin, dark cotton cloth, such as the black-out curtains that were in common use during the war [to stop enemy bombers from easily identifying cities by their illumination], thin paper, and dry, rotted wood to catch fire at distances up to 3,500 feet (0.66 mile) from ground zero (about 35 calories per square centimetre).”

In fact, the never-published secret source document for this statement, the U. S. Strategic Bombing Survey report number 92, The Effects of the Atomic Bomb on Hiroshima, Japan, May 1947 (not to be confused with the well-known deceptive unclassified propaganda report on both cities that they published in 1946), actually states on pages 4-6: “Six persons who had been in reinforced-concrete buildings within 3,200 feet [975 m] of air zero [i.e., (9752 - 6002)1/2 = 770 m ground range] stated that black cotton black-out curtains were ignited by flash heat... A large proportion of over 1,000 persons questioned was, however, in agreement that a great majority of the original fires were started by debris falling on kitchen charcoal fires....” The range of 770 metres is just 2,500 feet, not the 3,500 feet stated by Glasstone, 1957 (Glasstone misinterpreted the slant distance from air zero for the ground range).

So Glasstone 1957 on pages 307-8 stated that ignition of the most easily ignitable kindling materials, namely newspaper and dry rotted wood, from a 20 kt explosion occurs at 2-4 cal/cm2, while on pages 322-3 he stated that such ignitions required about 35 cal/cm2 for the nuclear explosions in Japan, an order of magnitude more energy! Part of this confusion was due to the effect of air humidity on water content of fine kindling, which - as everyone knows who as a kid has tried to light a fire using for kindling damp leaves or damp paper - is one key factor that increases the activation energy needed to start a fire. It also slows down fire spread, as at Hiroshima, where the fires had to drive out moisture from damp wooden houses, creating the black sooty rainfall when the moist sooty air condensed in the cool air high over the city. Like Hiroshima and Nagasaki, major strategic cities like New York, Los Angeles and London are either on the coast or on large river estuaries, which keeps the ground level humidity much higher than at the dry Nevada desert where most early ignition tests were made. Unlike Hiroshima and Nagasaki in 1945, no modern Western cities are built out of wood with easily flammable black colored wartime blackout curtains in the windows, which lowers the fire risk.

The same book points out on page 319 that in the dry air of the Nevada desert, only 12 cal/cm2 was needed at the 1953 Encore nuclear test to ignite houses made of rotted wood or surrounded by a trash filled yard and wooden fence (the whitewashed wooden house with a clear yard survived). Two wooden houses were also constructed for that test, exposing 4 x 6 foot windows with a line-of-sight exposure to ground zero. Both were subjected to the same 17 cal/cm2 thermal flash from the Encore nuclear test, and the one full of inflammables ignited with immediate flash-over to the entire room, while the one with modern fire-resistant furnishings survived with just minor smouldering which was extinguished by the recovery party when they entered the house an hour after the test.



A controversy over the 1957 Effects of Nuclear Weapons data flared up with the publication of J. Bracciaventi and F. DeBold, Critical Radiant Exposures for Persistent Ignition of Cellulosic Target Complex Materials, Naval Material Lab., Brooklyn, report AD-249476, DASA-1194, July 1960, which found that at 42% humidity newsprint needs at least 16 cal/cm2 for ignition. Glasstone wanted a check to be done before including the new data in The Effects of Nuclear Weapons, so the 1962 edition was published with the old false data, and the U. S. Naval Radiological Defense Laboratory and Naval Research Laboratory studied the problem, reporting in 1963 (e.g., S. Martin and A. Broido, Thermal Radiation and Fire Effects of Nuclear Detonations, 10 may 1963, AD042241, and S. Martin, Ignition of Cellulosic Kindling Fuels by Very Brief Radiant Pulses, USNRDL-TR-660, AD414174, 15 July 1963), which led to Glasstone’s February 1964 reprint of The Effects of Nuclear Weapons with corrected thermal ignition data, which is also used in the 1977 edition. One continuing problem with those simplified data tables is that they still do not state the humidity they actually apply to, and more importantly they ignore the effects of humidity on the inflammable thick-fuel materials that the easily-ignited fine tinder materials must ignite to cause persistent ignition:



Above: the three stages are usually required to start a persistent fire. Although the thermal radiation pulse can often both dry out and ignite fine kindling from a nuclear explosion with only a moderate increase in the required thermal energy as the humidity level rises, the effect of rising humidity on the ability of the ignited fine tinder to spread fire to thicker damp materials like kindling and wood, is disproportionate, so you get temporary ignition of fine tinder which then fails to cause a persistent fire. The reason is that damp thick-fuel materials like wood are disproportionately harder to ignite than thin damp materials like paper. The thermal pulse can dry out and then ignite paper because it is thin. The thermal pulse cannot dry out thick damp wood.

Glasstone and Dolan fail to take account of this problem in The Effects of Nuclear Weapons and Capabilities of Nuclear Weapons. This conceptual error in the analysis used for the effects of humidity in these manuals dates right back to 1952 Nevada nuclear test experiments in a dry desert, which just focussed on the moisture content of the tinder material and ignored the difficulty in starting a fire in a thick-fuel at the same humidity level using ignited fine tinder materials. Although fairly dry tree rotted tree punk could be ignited and sustain ignition, in reality it did not automatically cause a threat of igniting damp trees.

See the extensive summary of nuclear test data on ignition of kindling in H. D. Bruce and W. L. Fons, Effect of Moisture Content on the Critical Ignition Energies of Some Combustible Materials, Forest products Laboratory, Madison, Wi., report AD0153166, AFSWP-794, Secret - Formerly Restricted Data (original classification due to the summary of nuclear weapons test data on thermal ignition energies), October 1957 (notice the tardy date of publication, after Glasstone's June 1957 Effects of Nuclear Weapons and the November 1957 Capabilities of Atomic Weapons), which concludes on page 8:

“The thinner the material, the less the effect moisture content has on the critical ignition energy.”


Keith Arnold, Operation Snapper, Project 8.1, Effects of Atomic Explosions on Forest Fuels, U. S. Forest Service, Washington, D. C., AD0648231, WT-506, 1952: “Project 8.1 was designed to determine minimum thermal energies required to ignite common forest fuels, to determine blast-wave effect on persistence of ignition, and to provide field data against which laboratory source tests could be scaled. Prepared fuel beds of conifer needles, hardwood leaves, grasses, and rotten wood were exposed in Operation Snapper to total energies varying from 1 to 22 cal/sq cm. Thickness and density of fuel particles were determined prior to the test. Fuel moisture at shot time was measured in duplicate fuel beds, similarly located but outside the test area. Post-test fuel examinations showed that punky materials and fine grasses ignited and continued to burn at distances from ground zero where total thermal energy was approximately 3 cal/sq cm. Following Shots 3 and 4 punky materials were still burning upon recovery at H+2 hours.” [Although dry fine tinder materials ignited and continued to burn in the dry Nevada desert, they didn't constitute a threat of spreading fire to damp thick wood, which the thermal pulse could not dry out, as proved by Pacific nuclear test data we will review later in this post.]

“Sections simulating four types of frame building structures were exposed to Tumbler Shots 3 and 4. The four types were: (1) cubicle room with furnishings, (2) wall-corner, (3) cornice-corner, and (4) roof. Sections 2 and 3 were exposed with and without a fine flash fuel. Douglas-fir springwood was charred at least slightly out to about 13,000 feet (radiant exposure 5.1 cal/cm2) by Shot 4. Sustained burning, either as glowing or flaming, took place only in fine fuels. It was concluded that the flash of radiant energy from an atomic explosion; will set sustained primary fire in fine fuel, but in general not in more massive fuels such as lumber and plywood.”

- H. D. Bruce, Operation Snapper, Nevada Proving Grounds. Project 8.5. Incendiary Effects of Atomic Bomb Tests on Building Sections at Yucca Flat, Forest Products Lab., Madison, Wi., ADA995247, October 1952.




Above: the reported data in Glasstone and Dolan's Effects of Nuclear Weapons for thermal flash burns to skin is misleading since such burns would be prevented by normal clothing, as demonstrated from these Operation Cue photographs of dummies located at 1.3 mile (7,000 feet) from ground zero of the 29 kiloton Teapot-Apple II nuclear test, Nevada, May 5, 1955. Notice that the clothing failed to ignite and burn, despite being dark in colour, although it was bleached slightly in colour, and dark patterns in a light dress produced scorching to the underwear. Data on the protection against thermal radiation by clothing is given in the originally Confidential-classified 1957 Capabilities of Atomic Weapons, Table 6-2, page 6-4 (up to 120 cal/cm2 are required for skin blistering under clothing for large weapon yields, a large protection factor, since even if clothing does ignite the thermal radiation is directional so a person can roll over to extinguish the flames as the thermal pulse subsides; thermal radiation pulses are not like being doused with burning gasoline, contrary to anti-civil defense propaganda which in the 1980s ignored all the facts about actual thermal radiation pulse exposure and instead quoted the "example" of a man with 85% body area third-degree burns from being doused in burning gasoline, who died 33 days later at Massachusetts General Hospital after being given 501 blood transfusions including 281 units of plasma, 147 units of red cells, 37 units of platelets and 36 units of albumin, plus 6 operations and 4,900 medical personnel hours at a cost of $3,500 a day: all this proves is that being doused in burning gasoline has nothing to do with thermal radiation induced clothing ignitions). This data is omitted from unclassified books by Glasstone and Dolan.

U. S. Strategic Bombing Survey, The Effects of the Atomic Bombs on Hiroshima and Nagasaki, 19 June 1946:



Page 5: “In Hiroshima (and in Nagasaki also) the dwellings were of wood construction; about one-half were one story and the remainder either one and one-half or two stories. ... The type of construction, coupled with antiquated fire-fighting equipment [stored in wooden sheds] and inadequately trained personnel, afforded even in peacetime a high possibility of conflagration. Many wood framed industrial buildings were of poor construction by American standards. The principal points of weakness were the extremely small tenons, the inadequate tension joints, and the inadequate or poorly designed lateral bracings.”

Page 17: “Because of the brief duration of the flash wave and the shielding effects of almost any objects – leaves and clothing as well as buildings – there were many interesting cases of protection. ... The most striking instance was that of a man writing before a window. His hands were seriously burned but his exposed face and neck suffered only slight burns due to the angle of entry of the radiant heat through the window.”

Page 18: “... the thicker the clothing the more likely it was to give complete protection against flash burns. ... skin was burned beneath tightly fitting clothing but was unburned beneath loosely fitting portions. ... dark-colored clothing were most likely to be burned. ...”

Page 19: “A few burns resulted from clothing set afire by the flash wave, but in most cases people were able to beat out such fires without serious injury to the skin.”

Page 32: “Clothing ignited, though it could be quickly beaten out, telephone poles charred, thatched roofs of houses caught fire. In Hiroshima, the explosion started hundreds of fires almost simultaneously, the most distant of which was found 13,700 feet from ground zero; this, however, probably started when a building with a thatched roof collapsed on to a hot charcoal fire. Fires were started directly by flash heat in such easily ignitable substances as dark cloth, paper, or dry-rotted wood, within about 3,500 feet of ground zero; white-painted, concrete-faced or cement-stuccoed structures reflected the heat and did not ignite. ... The majority of the initial fires in buildings, however, were started by secondary sources (kitchen charcoal fires, electric short circuits, industrial process fires, etc.). ... Clothing as well as buildings afforded considerable protection against the flash. Even a clump of grass or tree leaf was on occasion adequate.”



Above: film of the Effects of Nuclear Weapons, including Encore nuclear test thermal ignition experiments on countermeasures against fire.




Above: thermal ignition nuclear test pages from Glasstone, 1964. Normal white-washed wood can't be ignited readily by yields below about 100 megatons unless it has paper trash piled around it or is decayed, because the thermal pulse is so short that a cloud of black smoke forms by ablation of less than 1 mm thickness of the wood. The smoke screens the underlying wood, preventing ignition as will be demonstrated.

"THERMAL IGNITION OF FRAMEHOUSES", testimony by Dr Frank H. Shelton (Technical Director of the U.S. Armed Forces Special Weapons Project), on page 28 of the U.S Congressional Joint Committee on Atomic Energy, Special Subcommittee on Radiation, Hearings entitled The Biological and Environmental Effects of War, June 22-26, 1959

Dr Shelton was asked to resolve the uncertainty as to whether persistent ignition can occur to a wooden house in a nuclear attack (in Hiroshima and Nagasaki, no houses were ignited by direct thermal radiation on the wood; instead the blast wave overturned charcoal cooking braziers used at breakfast time 8:15 am in Hiroshima and for preparing lunch at 12:01 pm in Nagasaki, although a few fires were ignited as we shall see in black-colored air raid "black out" curtains in windows - which are no longer used, modern light-colored curtains requiring far larger ignition energies). Shelton responded by assembling extracts from four paragraphs (7.62, 7.93, 7.82 and 7.38)
of Glasstone's June 1957 Effects of Nuclear Weapons as follows:

"7.62 Wood is charred by exposure to thermal radiation, the depth of the char being closely proportional to the energy received. For sufficiently large amounts of energy, wood in some massive forms may exhibit transient flaming, but persistent ignition is improbable under the conditions of a nuclear explosion. However, the transitory flame may ignite adjacent combustible material which is not directy exposed to the radiation. ...

"7.93 From the evidence of charred wood found at both Hiroshima and Nagasaki, it was originally concluded that such wood had actually been ignited by thermal radiation and that the flames were subsequently extinguished by the blast. But it now seems more probable that, apart from some exceptional instances, such as [the ignition of adjacent combustible trash by the transient flames], there was no actual ignition of the wood. The absorption of the thermal radiation caused charring in sound wood but the temperatures were generally not high enough for ignition to occur. Rotted and checked wood and excelsior, however, have been known to bur completely, and the flame is not greatly affected by the blast wave.

"7.82 The fact that accumulations of ignitable trash close to a wooden structure represent a real fire hazard was demonstrated at the nuclear tests carried out in Nevada in 1953. In these tests, three miniature wooden houses, each having a yard enclosed with a wooden fence, were exposed to 12 calories per square centimeter of thermal radiation. One house, at the left, had weathered siding showing considerable decay, but the yard was free from trash. The next house also had a clean yard; and, further, the exterior siding was well maintained and painted. In the third house, at the right, the siding which was poorly maintained, was weathered, and the yard was littered with trash.

"7.38 The state of the three houses after the explosion was as follows: the third house, at the right, soon burst into flame and was burned to the ground. The first house, on the left, did ignite but it did not burst into flame for 15 minutes. The well-maintained house in the center with a clean yard suffered scorching only."





Above: people escaping the firestorm in the bamboo furnishings and paper screen filled wooden houses at Hiroshima, where thermal ignition was due to black coloured air-raid "blackout" curtains (which ignite easily, unlike light colours), and the overturning of thousands of household charcoal cooking braziers used during the breakfast-time attack in Hiroshima (the Nagasaki attack occurred when lunch was being prepared). The firestorm did not develop instantly, and lying propaganda is debunked by the facts:

‘The evidence from Hiroshima indicates that blast survivors, both injured and uninjured, in buildings later consumed by fire [caused by the blast overturning charcoal braziers used for breakfast in inflammable wooden houses filled with easily ignitable bamboo furnishings and paper screens] were generally able to move to safe areas following the explosion. Of 130 major buildings studied by the U.S. Strategic Bombing Survey ... 107 were ultimately burned out ... Of those suffering fire, about 20 percent were burning after the first half hour. The remainder were consumed by fire spread, some as late as 15 hours after the blast. This situation is not unlike the one our computer-based fire spread model described for Detroit.’

- Defense Civil Preparedness Agency, U.S. Department of Defense, DCPA Attack Environment Manual, Chapter 3: What the Planner Needs to Know About Fire Ignition and Spread, report CPG 2-1A3, June 1973, Panel 27.

The originally ‘secret’ May 1947 U.S. Strategic Bombing Survey report on Nagasaki states (vol. 1, p. 10):

‘... the raid alarm was not given ... until 7 minutes after the atomic bomb had exploded ... less than 400 persons were in the tunnel shelters which had capacities totalling approximately 70,000.’

This situation, of most people watching lone B-29 bombers, led to the severe burns by radiation and flying debris injuries in Hiroshima and Nagasaki. The originally ‘secret’ May 1947 U.S. Strategic Bombing Survey report on Hiroshima, pp. 4-6:

‘Six persons who had been in reinforced-concrete buildings within 3,200 feet [975 m] of air zero stated that black cotton black-out curtains were ignited by flash heat... A large proportion of over 1,000 persons questioned was, however, in agreement that a great majority of the original fires were started by debris falling on kitchen charcoal fires... There had been practically no rain in the city for about 3 weeks. The velocity of the wind ... was not more than 5 miles [8 km] per hour....

‘The fire wind, which blew always toward the burning area, reached a maximum velocity of 30 to 40 miles [48-64 km] per hour 2 to 3 hours after the explosion ... Hundreds of fires were reported to have started in the centre of the city within 10 minutes after the explosion... almost no effort was made to fight this conflagration within the outer perimeter which finally encompassed 4.4 square miles [11 square km]. Most of the fire had burned itself out or had been extinguished on the fringe by early evening ... There were no automatic sprinkler systems in building...’

The vital six secret volumes of the U.S. Strategic Bombing Survey consist of three volumes on Hiroshima dated May 1947 and three on Nagasaki dated June 1947. (These are completely separate from the brief unclassified summary on the effects published by the U.S. Strategic Bombing Survey in 1946.) These secret volumes were finally declassified in 1972 and may be inspected at the British National Archives, as documents AIR 48/160, AIR 48/161, AIR 48/162, AIR 48/163, AIR 48/164, and AIR 48/165.

Dr Ashley Oughterson and Dr Shields Warren noted a fire risk in Medical Effects of the Atomic Bomb in Japan (McGraw-Hill, New York, 1956, p. 17):

‘Conditions in Hiroshima were ideal for a conflagration. Thousands of wooden dwellings and shops were crowded together along narrow streets and were filled with combustible material.’



Above: seasoned ponderosa pine and douglas fir wood was just surface-charred to less than 1 mm depth (regardless of intensity), and not ignited, by a 30 kiloton TEAPOT Nevada test in 1955. The depth of charring shown in the curves are experimentally accurate to within +/- 10 % and apply to normal incidence (face-on exposure). (If the wood is exposed at angle A to the direction of the fireball, the radiant exposure needed for the same depth of charring is increased by the factor 1/cosine A.) Source: Kyle P. Laughlin, Thermal Ignition and Response of Materials, Report to the Test Director, Operation TEAPOT, Nevada Test Site, February-May 1955, Office of Civil and Defense Mobilization, weapon test report WT-1198, December 1957 (declassified in July 1960), AD0611227. Laughlin exposed many inflammable materials to 30 kt Nevada nuclear weapons tests at Operation TEAPOT in 1955, discovering that thermal ignition to cause fires required thin kindling fuels (particularly newspaper litter, straw or sawdust), while thick inflammable materials such as plywood just undergo thermal ablation, i.e. the emission of smoke due to the vaporization of a fraction of a millimetre of the surface layer (e.g., the outer paint layer). The smoke produced in this way by the first part of the thermal radiation then shields and protects the underlying wood from reaching ignition temperature! Laughlin concludes his report as follows:

"Timber impregnated with flammable preservative oils, when painted with a white-pigmented fire-retarded coating composition [i.e. simply white-wash] whose chemical and physical characteristics fulfil requirements as specified by the Engineering Division of the Association of American Railroads, should be capable of resisting the thermal effects of atomic devices if the structure survives physically the effects of the blast wave. [For higher yield devices, even more thermal radiation exposure is required for the same effect, because the longer duration of the thermal pulse for bigger weapons produces a smaller temperature rise in any given material.]"

This had been known since the very first nuclear test, TRINITY (July, 16 1945):

‘The measured total radiation at [9.1-km] from the centre was 0.29 calories/cm2 ... Examination of the specimen exposed at [975 m] shows ... the charred layer does not appear to be thicker than 1/10 millimetre.... scorching of the fir lumber used to support signal wires extended out to about [1.9 km] ... the risk of fire due to the radiation ... is likely to be much less than the risk of fire from causes existing in the buildings at the time of explosion.’ – W. G. Marley and F. Reines, July 16th Nuclear Explosion [TRINITY, 1945]: Incendiary Effects of Radiation, Los Alamos report LA-364, October 1945, originally Secret, pp. 5-6.

“... the flow of heat [even within the fireball] into a massive object, such as a shot tower, shield, or coral rock, will be comparatively slow [in comparison to the brief duration of high fireball temperatures] even with a high temperature gradient. Consequently, the interior portions of large structures in the neighborhood [of the fireball] may not receive enough heat to evaporate ...”

- S. L. Whitcher, et al., Operation HARDTACK, Project 2.8, U.S. Naval Radiological Defense laboratory, weapon test report WT-1625 (1961), p. 12.

“The fact that only a thin layer of sand was actually either vaporized or melted, even though in contact with the fireball ... indicates that the thermal effects penetrate only superficially into solid material during the short duration of the very high temperatures. By computing the energy required to heat, decarbonate, and melt 264 tons of coral sand and to heat, melt and vaporize 165 tons of iron ... 8.5% of the available radiant energy [i.e., 3% of the 15.2 kt yield of the 61-m high tower REDWING-INCA test, because the radiant energy was 35% of the total energy of the explosion] was utilised for heating the tower and soil material.”

- Charles E. Adams and J. D. O’Connor, U.S. Naval Radiological Defense Laboratory, report USNRDL-TR-208, 1957, p. 13.

"An investigation was undertaken to determine the probability of ignition of thick woods by thermal radiation. ... Measurements were made to determine the irradiance and time necessary to produce glow and flaming ignition in ponderosa pine, Douglas fir, and maple. ... It was concluded that for sound solid woods of a normal moisture content, it is almost impossible to start continued ignition with nuclear weapons of a size less than about 100 Mt at a distance where blast damage would not be severe." [Emphasis added.]

- F. W. Brown, III, Ignition of Thick Wood Specimens by High-Temperature Thermal Radiation, Naval Civil Engineering Lab., California, 1965, report AD0475535.

"The radiant exposure to ignite tinder materials for thermal radiation from nuclear weapons was measured. The experiments involved 41 materials commonly encountered in urban areas and are to provide basic data of direct use in the determination of fires caused by nuclear weapons and to provide basic information for ignition prediction models. The radiant exposures for ignition of the most susceptible common material, newspaper (dark picture) ranged from 5.1 cal/cm2 to 31 cal/cm2 for bursts of 20 kt to 100 Mt respectively. Black roll roofing, a common material representing an important but less susceptible fuel, ignited at 38 cal/cm2 for a 1 MT pulse and 45 cal/cm2 for a 10 Mt pulse. Other thin fuels ignited at various intermediate or higher exposures."

- John Bracciaventi, R. Heilferty, and Willard L. Derksen, Radiant Exposures for Ignition of Tinder by Thermal Radiation from Nuclear Weapons, Naval Applied Science Lab., Brooklyn, 1966, report AD0640595.

ABOVE: U.S. Army photo showing how a mere leaf of Fatsia japonica attenuated the heat flash enough to prevent scorching to the bitumen on an electric pole near the Meiji Bridge, 1.3 km range, Hiroshima. It didn't even vaporize the leaf before the pulse ended, let alone did it somehow ignite the wooden pole (most photos claiming to show thermal flash radiation effects in Hiroshima and Nagasaki purely show effects from the fires set off by the blast wave overturning cooking stoves, which developed 30 minutes to 2 hours later).

'Even blades of grass cast permanent shadows on otherwise badly scorched wood. The [Hiroshima nuclear bomb heat] flash lasted less time than it took the grass to shrivel.' - Chapman Pincher, Into the Atomic Age, Hutchinson and Co., London, 1950, p. 50.

ABOVE: the heat flash radiation which causes the scorching is so unscattered or unidirectional that any shading from the fireball source stops it even if you are exposed to the scattered radiation from the rest of the sky: shadows still present in October 1945 in the bitumen road surface of Yorozuyo Bridge, 805 m SSW of ground zero, Hiroshima, pointed where the bomb detonated (U.S. Army photo).

“The foliage making up the crowns [upper branches and leaves] of the trees, while it has a high probability of being exposed to the full free-field radiation environment from air bursts... may, however, materially reduce the exposure of the forest floor by generating quantities of smoke and steam, as well as by direct shading.” - Philip J. Dolan, Capabilities of Nuclear Weapons, U.S. Defense Nuclear Agency, 1978 revision, Secret – Restricted Data, Chapter 15, "Damage to Forest Stands", paragraph 15-9.

"Green leaves and needles on tree crowns smoke and char but do not ordinarily sustain ignition. This smoke production materially reduces the radiant exposure of the ground surface." - Capabilities of Atomic Weapons, U.S. Department of Defense, TM 23-200, Confidential, 1960, page 11-2.

“Fuels seldom burn vigorously, regardless of the wind conditions, when fuel moisture content exceeds about 16 percent. This corresponds to an equilibrium moisture content for a condition of 80 percent relative humidity. Rainfall of only a fraction of an inch will render most fuels temporarily nonflammable and may extinguish fires in thin fuels... Surface fuels in the interior of timber stands are exposed to reduced wind velocities; generally, these fuels retain their moisture as a result of shielding from the wind and shading from sunlight by the canopy.” - Philip J. Dolan, Capabilities of Nuclear Weapons, U.S. Defense Nuclear Agency, 1978 revision, Secret – Restricted Data, Chapter 15, "Damage to Forest Stands", page 15-60. (This material can also be found in the U.S. Department of Defense's Capabilities of Atomic Weapons, TM-23-200, Confidential, 1960, p. 11-3.)



Above: Figure 6.24a of the 1957 Effects of Nuclear Weapons showing effect of a nuclear explosion giving a peak overpressure of 3.8 psi to a natural Pisonia dominated forest stand (similar to American beech forests) with a mean tree height of 50 feet and a mean diameter at the stem base of 2 feet (note that the test report WT-921 states that at 8,800 feet where the peak overpressure was 4.2 psi some 58% of trees were snapped so the figure of 90% given by Glasstone 1957 is not justified; about 50% of the trees were broken by 3.8 psi not 90%); this photo is identified as Bikini Atoll's Eniirikku (codenamed Uncle by America) Island, at a position just 9,300 feet from the 110 kt CASTLE-KOON nuclear surface burst test of 1954 in Figure 3.8 on page 38 of the originally Secret - Restricted Data report on forest stands exposed at Operation Castle, WT-921. Notice that the forest was not ignited; it did not burn contrary to anti-civil defense lies which are popularized by propaganda (which we will discuss in detail later).



Above: Fig 6.24b in the 1957 Effects of Nuclear Weapons: 175 trees/acre natural Pisona tree stand on Rukoji (codenamed Victor by America) Island of Bikini Atoll, subjected to 2.4 psi peak overpressure at 62,500 ft or about 12 miles from CASTLE-BRAVO 14.8 Mt surface burst ground zero, Bikini Atoll, 1954. This photo is identified for distance and nuclear test at 33 minutes and 17-22 seconds time in the declassified film Military Effects Studies on Operation Castle, below. Pisona is a beech-like broadleaf tree and those in this forest stand has an average height of 80 feet with an average stem diameter at its base of 3 feet. Where 30% of the trees are blown down by the blast wind pressure, the overall effect is similar to the much longer-lasting 95 miles/hour winds of a natural hurricane. Notice that neither natural forest stand at Bikini Atoll was incinerated by fire!

According to Glasstone 1957, this forest stand suffered 30% tree stem breakage, but report WT-921 page 43 states that 65% of the tree stems in this stand were snapped. Glasstone 1957 just used the photographs to illustrate its predictive system which is based on 30% and 90% tree breakage, instead of reporting the actual percentage damage reported in WT-921. The CASTLE-BRAVO shot also produced light tree damage (no stem breakage, just 30% branch breakage) to a Pisonia forest on Eniirikku (codenamed Uncle by America) Island, 75,400 feet or about 14 miles from ground zero, where the peak overpressure was 1.7 psi, according to page 28 of W. L. Fons and Theodore G. Storey, Operation Castle, Project 3.3, Blast Effects on Tree Stand, U.S. Department of Agriculture, Forest Service, Division of Fire Research, Secret - Restricted Data, report WT-921, March 1955.

“Measurements to determine critical ignition energies for various materials and depth of char in wood were made during Shot Cherokee [3.8 Mt air burst at 4,350 ft altitude, 21 May 1956] from stations on Sites Dog [Yurochi Island in the Bikini Atoll, 8.0 km from ground zero, 74 cal/cm2 measured] and George [Aomoen Island in the Bikini Atoll, 12 km from ground zero, 21 cal/cm2 measured]. In addition, various natural kindling fuels on several Islands were studied prior to and after the detonation. ... Some of the specimens of black and gray alpha-cellulose papers, newspapers, and pine needles were ignited ... None of the grass, cotton denim, rayon cloth, or white alpha-cellulose papers were ignited. Corrugated fiberboard was burned on Site Dog by the radiation.”

- Operation Redwing, Technical Summary of Military Effects, Programs 1-9, nuclear weapon tests report WT-1344, ADA995132, 1961, p 219.


Other reports on Nevada effects on trees and forest stands are Operation Tumbler-Snapper report WT-509, 1953, and Operation Upshot-Knothole report WT-731, 1954. The Upshot-Knothole experiment exposed a coniferous tree stand of 145 ponderosa pine trees 51 feet in average height to 4.5 psi peak overpressure. The forest stand smoked during the thermal pulse, but did not ignite. Hence, both in Pacific and Nevada tests, trees did not burn even relatively close to ground zero. E. H. Engquist C. W. Forsthoff of Chemical and Radiological Labs., Maryland, reported in Operation Upshot-Knothole, Project 8.4-2, Evaluation of a Thermal Absorbing Carbon Smoke Screen, WT-769, February 1954, that a smoke screen similar in height to that produced by thermal radiation on a forest canopy, 80-90 feet above the ground, produced by burning about 275 gallons of carbon containing material per square mile, absorbed 78-90% of the thermal radiation on the ground.



These photos were both published in the 1957 edition of The Effects of Nuclear Weapons, but they were deleted from all subsequent editions of that unclassified book: they appeared ultimately in the highly classified (Secret - Restricted Data) film of the military effects of the test series and the locations are also identified in the report Operation Castle, Project 3.3, Blast Effects on the Tree Stand, weapon test report WT-921, U.S. Forest Service, W. L. Fons (Project Officer). The lack of thermal ignition of forests even using very high yield nuclear weapons was deemed secret. This hindered civil defense, by obfuscating the facts. Flawed thermal ignition tests and a thermal radiation transmission theory which grossly exaggerated the thermal effects both combined to exaggerate effects and make civil defense appear useless. (The nuclear test data was secret, with limited print runs that nobody in a position to repudiate anti-civil defense propaganda had proper access to - or if they did have access to it - they were prevented from publishing it by the severe penalties laid down in laws such as the Atomic Energy Act of 1954.)



Above: a page from the 1957 Effects of Nuclear Weapons indicating the reason why the trees didn't burn is the same as the reason why this wooden house didn't burn: the thermal pulse from a nuclear weapon is too brief to do more than ablate a thin surface layer of the material, literally creating a smoke screen which immediately protects the underlying material from ignition. Dolan explains this in the 1,651 pages long 1972 Secret - Restricted Data U.S. Department of Defense Capabilities of Nuclear Weapons but - although he and Glasstone explained it clearly in the 1977 Effects of Nuclear Weapons - the point was not widely grasped. There were relatively few fires in nuclear tests, compared to what propaganda forecasts by the use of totally naive assumptions concerning thermal radiation transmission through the atmosphere, and the energy needed to ignite materials. Hiroshima and Nagasaki were burned entirely by means of the blast wave overturning charcoal cooking braziers in thousands of homes at the breakfast and lunch times of the bombings, as was revealed in polls of survivors when the secret volumes of the U.S. Strategic Bombing Survey were eventually declassified.



As discussed in a previous post about blast caused fires in Hiroshima and Nagasaki, nuclear tests were conducted in 1953 and 1955 to see if white-washing wooden houses would reflect the heat flash and prevent ignition: it worked! Various types of full scale houses were exposed on March 17, 1953 to 16-kiloton Annie and on May 5, 1955 to 29-kiloton Apple-2 in Nevada. The front of the houses was charred during the intense radiant heat flash, but none of them ignited, even where the blast was severe enough to physically demolish the house. Fences and huts exposed at the 27 kiloton 8 May 1953 test, Encore, had to be covered in rubbish to ignite: see this film.

‘Dense smoke, and even jets of flame, may be emitted [by wood], but the material does not sustain ignition [directly by heat flash] ... smoke formed in the early stages will partially shield the underlying material from subsequent radiation. This behaviour is illustrated in the photographs taken of one of the wood-frame houses exposed in the 1953 Nevada tests... the house front became covered with a thick black smoke... within less than 2 seconds from the explosion, the smoke ceased... Ignition of the wood did not occur... The thermal energy incident upon the material was apparently dissipated in the kinetic energy of the "exploding" surface molecules before the radiation could penetrate into the depth of the material.’

Dr Samuel Glasstone and Philip J. Dolan, editors, The Effects of Nuclear Weapons, U.S. Department of Defence, 1977, pp. 285-6.

Physically, wood and also skin are poor heat conductors. The top tenth of a millimetre can reach high surface temperatures briefly if exposed directly to a large thermal energy exposure from the fireball, but that doesn't mean they conduct heat effectively into the depth of material within the time available. House tiles at ground zero in Japan received around 100 cal/cm^2 or so and this blistered the surface, but only the very surface! You can briefly open and look into a conventional oven without being heated up vaporization point by the 250 C or whatever temperature of the food inside, because you take time to heat up. The heat flash from a nuclear detonation is not microwaves. It is just plain old fashioned infra-red, which gets stopped easily. Things which are good conductors of the heat flash also tend to reflect it and dissipate it. Metal for instance doesn't respond to the heat flash unless it is in an extremely thin foil. (There were some problems with U.S. aircraft flying near high-yield nuclear test explosions, when very thin alloy foil covering the wings and tail exposed to the fireball were weakened by the heat flash, just prior to the arrival of the blast wave, which was then able to bend or buckle the surface.)

'Walking across burning coals is no big deal ... just a matter of freshman physics: the coal simply does not have good enough heat conduction properties to transfer enough energy to your foot to burn it as you walk across.'

'When you are next baking some potatoes or a pie, open the oven. Everything in there is at the same really high temperature. You can touch (for a short time) the potatoes and the pie quite comfortably. But you would never touch the metal parts of the oven, right?'


Nevada, 8 May 1953. Wooden sheds resisted direct ignition by a thermal flash of 12 calories per square cm at ground range of 7,700 ft from the Encore nuclear test (27 kt air drop with detonation at 2,423 feet altitude), despite ‘smoking’ during exposure. But a badly decayed dark wooden fence and piles of old leaves and newspaper trash set their adjacent sheds on fire within 15 minutes. The light-painted shed with a tidy yard survived. These 'house in the middle' thermal ignition tests were documented and illustrated in Glasstone's Effects of Nuclear Weapons 1962-4 (page 343 for example), but the data were removed from the 1977 edition, along with the entire civil defence chapter, to make way for a new chapter on EMP damage.

The toroidal red (nitrogen dioxide colored) fireball seen from an aircraft casts a shadow on Nevada: 1953. The fireball does not last long near ground zero, because hot air rises.
The house on the left has a dark-coloured, unpainted, badly decayed fence; the house on the right has loads of rubbish (old newspapers, straw, etc.) piled against the fence. The house in the middle is clean and painted white.

The 12 cal./sq. cm light and thermal radiation hits the houses. The rubbish around the house on the right is already ignited.
The 3.5 psi peak overpressure blast wave arrives, with the wind pressure blowing up a dust cloud.
The decayed fence and the rubbish cause fires which spread to the adjacent houses.
Only the house in the middle survives, albeit scorched and battered from the heat and blast.
Notice scorching of white paint on fence and house. Blast partly demolished the door and fence.
Close up of rubbish of the house on the right igniting during radiant exposure of 12 cal./sq. cm.

Close up of 3.5 psi peak overpressure blast hitting the house, blowing flaming rubbish about and ripping off roof covering.

Wooden house is ignited by the resulting external fire within 15 minutes of detonation.
Remains look like Hiroshima.
Interior ignition tests: piles of inflammable newspaper trash indoors will set the house on the right on fire due to thermal radiation entering the large window and igniting newspapers and other kindering scattered around indoors, but the identical house beside it on the left will survive because inflammable trash has been removed.Page 343 of the 1962 edition of The Effects of Nuclear Weapons:

‘The value of fire-resistive furnishings in decreasing the number of ignition points was also demonstrated ... where the thermal radiation exposure was 17 calories per square cm... draperies were of vinyl plastic, and rugs and clothing were made of wool ... the recovery party, entering an hour after the explosion, was able to extinguish the fires [in the tidy house].’


The blast tears off part of the roof of each house.
Notice charring of the front of each house. But only the house on the right is ignited, due to heat flash entering through the window which has a clear line-of-sight view of the fireball, and igniting kindering (rubbish like old newspapers which was left scattered around).

The house on the left was did not burn (one chair was partly burned, but it was only smouldering at 1 hour after burst when the recovery party arrived, and they easily extinguished it). The other house (on the right) burned down completely; there is nothing but ash left.

Dr Ashley Oughterson and Dr Shields Warren noted a fire risk in Medical Effects of the Atomic Bomb in Japan (McGraw-Hill, New York, 1956, p. 17):

‘Conditions in Hiroshima were ideal for a conflagration. Thousands of wooden dwellings and shops were crowded together along narrow streets and were filled with combustible material.’

I've already quoted Stanbury's rebuttal of television propaganda about thermal effects from nuclear weapons on this blog:

Here is a taste of how Stanbury, who attended the October 1952 Hurricane 25 kt British test to measure the effects, reacted to senile physicists' propaganda:

‘We have often been accused of underestimating the fire situation... we are unrepentant in spite of the television utterances of renowned academic scientists... Air cannot get into a pile of rubble 80% of which is incombustible anyway. This ... is the result of a very complete study of some 1,600 flying bomb incidents... Secondly, there is a considerable degree of shielding of one building by another... Thirdly, even when the windows of a building can "see" the fireball, and something inside is ignited... even with the incendiary bomb the chance of a continuing fire developing in a small room is only 1 in 5 ...’

– George R. Stanbury, ‘The Fire Hazard from Nuclear Weapons’, Fission Fragments, Scientific Civil Defence Magazine, No. 3, August 1962, pp. 22-6, British Home Office, Scientific Adviser’s Branch, originally classified 'Restricted'.

FURTHER INFORMATION:

How Hiroshima and Nagasaki were ignited (mainly by blast overturning cooking stoves at 8.15 am - Breakfast time - and 12.01 pm - lunch time): http://glasstone.blogspot.com/2006/03/fires-from-nuclear-explosions.html

Thermal ignition is not a problem from bursts at high altitude or in space: http://glasstone.blogspot.com/2006/03/checkmate-detonation-as-seen-from.html



UPDATE ON THERMAL IGNITION ANALYSIS (20 May 2009):








Above: because it didn't contain charcoal cooking stoves surrounded by paper screens and bamboo furnishings, this American two-story wood frame house survived unburned 25 cal/cm2 thermal radiation with just white-washed paint (which was quickly charred off) before the house was blown up by 5 psi (35 kPa) peak overpressure at 3,500 feet from 16 kt UPSHOT KNOTHOLE-ANNIE on 17 March 1953, Nevada Test Site; anti-civil defense propaganda in 2004 Cornell-published book by Lynn Eden Whole World on Fire while quoting in detail Dr Glasstone's 1957 Effects of Nuclear Weapons statement that the house had whitewash on it (just like most wooden houses) completely ignores the fact that Dr Glasstone states in paragraph 7.30 on page 292 of the 1957 Effects of Nuclear Weapons: 'a material which blackens (or chars) readily in the early stages of exposure to thermal radiation behaves essentially as black, i.e., as a strong absorber irrespective of its original color. [Emphasis added.] On the other hand, if smoke is formed [by dark coloured wood] it will partially shield the underlying material from the subsequent radiation.' Lynn Eden also ignores the facts that:

(1) the ordinary white-washed (quite normal) house did not ignite or burn despite being charred by the thermal flash and covered in black smoke due to thermal radiation. Lynn falsely claims that the whitewash was a 'heroic' precaution to avoid ignition. But it was burned off. Even unpainted poles in Hiroshima didn't catch fire, they just charred. Window blinds were blown in by the blast. So these things which Lynn biasedly sees as bad didn't prevent fire, because as other tests like ENCORE (which we will discuss below in detail) proved it takes more than a brief pulse of heat to set thick wood on fire. Anyway, the safeguards aren't 'bad' but are actually good benefits which would help survival by minimising glass fragments and flash burns. Contrary to the totally false and civil defence demeaning impression given by Lynn Eden's prejudiced, partial quotations from Dr Glasstone's 1957 edition, rooms don't need metal window blinds: in an attack warning you can instantly protect rooms containing beds or upholstered furniture and a window which would potentially let in thermal radiation by simply drawing curtain, or by simply taping sheets of white paper over the inside of the window glass - which will protect against thermal radiation for the crucial interval of time until the delayed arrival of the blast wave!

(2) the basement survived, and

(3) the house was not knocked over by the blast overpressure; the front was cracked by the reflected overpressure and the roof was peeled off by the blast winds, but then the house exploded due to the low pressure (suction) phase of the blast occurring while there was still overpressure trapped inside the house (which had entered through the windows but could not escape as fast as the external pressure dropped). This is vital because it shows that most of the debris (with the exception of window glass) was blown outwards from the exploding house, not inwards against the occupants. Although debris landed on the family car and dented the roof, it could still be driven away after the explosion, illustrating that the debris load from the collapse of a house is not always the end of the universe as portrayed by evil propaganda. (More about building collapse and blast effects on survival can be found in the blog post linked here.)



Above: Mannequins at 2.1 km ground range from the 29-kt TEAPOT-APPLE 2 Nevada 500 ft altitude tower test on 5 May 1955. Clothes did not ignite, but the exposed colour of a dark suit faded while a dark pattern on a dress was burned on to the underwear. Clothing protects skin.



Above: UPSHOT KNOTHOLE-ENCORE 27 kt air burst at 2,423 feet altitude at the Nevada nuclear test, 8 May 1953. Wooden houses, black and white, resisted ignition by a thermal flash of 12 calories/cm2, despite ‘smoking’ during exposure. But a badly decayed dark wooden fence and piles of old leaves and newspaper trash set their adjacent houses on fire within 15 minutes. The light-painted house with a tidy yard survived. Far right: two wooden houses 10-by-12 feet in size with large windows facing ground zero were exposed to 17 calories/cm2 from ENCORE. In one house piles of inflammable newspaper trash indoors set a house on fire due to thermal radiation from ENCORE entering the large window, but an identical house beside it survived because inflammable trash had been removed! Page 343 of the 1962 edition of The Effects of Nuclear Weapons explains the significance of this ENCORE test:

‘The value of fire-resistive furnishings in decreasing the number of ignition points was also demonstrated ... where the thermal radiation exposure was 17 calories/cm2 ... draperies were of vinyl plastic, and rugs and clothing were made of wool ... the recovery party, entering an hour after the explosion, was able to extinguish the fires.’

Note that the house which did burn which was loaded with trash with a large window facing the fireball and underwent immediate room 'flashover' with no delay because all the easily ignited trash in it simultaneously burst into flames. Lynn Eden falsely makes a great issue out this fact in her 2004 book Whole World on Fire: Organizations, Knowledge, and Nuclear Weapons Devastation, on pages 256-7, where she simply ignores the vitally important civil defence fact that the identical house with the trash like old newspapers and highly inflammable old type furniture removed did not undergo instant flashover!

The immediate flashover effect was confirmed at the 1 kt high explosive test DIRECT COURSE in New Mexico, October 1983. There was no surprise there: light tinder filled rooms facing the fireball and irradiated with 17 cal/cm2 instantly burst into flame, but clean tidy rooms without trash don’t, even if they face the fireball. This is what ENCORE proved!

ENCORE nuclear test report on thermal ignition of wooden houses

H. D. Bruce, Incendiary Effects on Building and Interior Kindling Fuels, Project 8.11a, US Forest Service, Forest Products Laboratory. Albuquerque, NM.: Field Command, AFSWP, weapons test report WT-774 (AD0460272), December 1953. Abstract:

“This investigation was part of an overall thermal radiation program of the Armed Forces Special Weapons Project conducted to ascertain the thermal effects of atomic weapons. The purpose of this investigation was to obtain sufficient information on those factors which affect the initiation of primary fires to aid in the prediction of probability of primary fires being ignited in urban target areas by atomic weapons. The immediate objective of the combined laboratory and field program ... was to develop a method by which predictions could be made of the number and distribution of primary fires which may be expected from an atomic bomb detonation over any urban area. This program began with a survey of several selected cities to establish the frequency of occurrence of possible fuels and to develop survey techniques. This phase was followed by a laboratory program in which the more abundant external and internal kindling fuels, as well as selected building materials, were tested for their flammability as indicated by critical ignition energy values. The effect of blast in extinguishing flame was also considered. Field tests served to amplify and corroborate laboratory results.”



Thomas Goodale's report Effects of Air Blast on Urban Fires, URS Research Company, California, report URS 7009-14, also AD723429, December 1970, showed that where thermal radiation from a simulated 1 megaton burst ignites curtains and papers, the blast wave arrived and blew fires out. At 1 psi, 50% of burning curtains are extinguished by the blast wave, burning fragments from the remainder can be blown into the room by a peak overpressure of 1 psi. But in all case above 2.5 psi peak overpressure, 100% of incipient fires were extinguished by the blast wave, unless the whole room was filled with tindering like newspaper trash and directly facing the fireball so as to suffer immediate 'flashover' like the trash filled room exposed to ENCORE.

Blast winds displace flames and cool the burning material to temperatures below those needed for ignition, thus extinguishing fires. Burning beds, all curtains and upholstered furniture are only extinguished by peak overpressures of 2.5 psi and higher. The beds and upholstered furniture may then continue to smoulder, and can rekindle into fires after 15 minutes or more. During this time it is very easy to stamp out the potential fires.

Lynn Eden falsely comments on Goodale's research in her 2004 book Whole World on Fire: Organizations, Knowledge, and Nuclear Weapons Devastation, where she writes on page 218 that:

'The next year [1971] Goodale conducted more experiments ... One experiment examined the effects of blast overpressures of up to 9 psi on the smoulder that remained after the flames had been blown out. These findings, however, were not conclusive: "The higher overpressures did not produce a smoulder-extinction counterpart to the blowout of flames. No trend was evident".'

This statement about the trend in smoulder extinction with increasing peak overpressure, has nothing to do with the fact that blast waves do extinguish 100% of solid fuel (not burning liquid fuel pans or burning papers and trash such as in the ENCORE room) of incipient fires above 2.5 psi, even if some are left in a smouldering condition at high overpressures and can re-ignite if not dowsed with water or stamped out.

Lynn Eden continues:

'Another experiment showed a very different outcome in which low blast pressure could increase fire spread. In this study, Goodale subjected burning curtains to blast overpressures of 1 psi "only to discover that transport of burning curtain fragments may become a considerable hazard under suitable conditions".'

Ignition of curtains depends on the curtain colour (curtains with common white linings are resistant to ignition by thermal radiation), but if they are ignited it is true that when blasted into a room they can cause fires under some conditions. yet this does not discredit the finding that other internal room fires are blown out by the blast wave. Burning curtain fragments are easy to deal with, by stamping out. It is not an immediate flashover mechanism, like the trash filled ENCORE room.

Even where rooms are ignited by thermal radiation, this does not instantly spread burn the house down, unless the room is filled with fine tindering such as trash newspapers, magazines, etc., as in the ENCORE room which burned rapidly by immediate flashover (contrasted to the identical room without trash which did not undergo immediate flashover and was extinguished an hour later by the recovery party). It takes 17 minutes for 50% of normal living room fires to 'flashover' so that the whole room bursts into flame, and 8 minutes for 50% of bedroom bed ignitions to flashover to the rest of the room. (F. J. Vodvarka and T. E. Waterman, Fire Behavior, Ignition to Flashover, IIT Research Institute, Chicago, report AD618414, June 1965.) Until flashover occurs, it remains possible to extinguish the fire with water, sand, or by beating it out with wet blankets.

Collaborated evidence from observers at Hiroshima shows that the ignition of dark air raid blackout curtains occurred at up to 1.1 km from ground zero, whereas the more likely blast ignition due to overturned charcoal cooking stoves caused a firestorm to burn everything within an average radius of 1.9 km. Curtain ignition was limited to rooms facing the explosion with uninterrupted line-of-sight to the fireball. Now that upholstery fabrics are fire retardant by law, research has been done into the risk of internal house fires being started by bits of ignited window curtains being thrown into rooms. The main risk occurs if there are piles of old newspapers in the rooms which can act as tinder, because the wood used in flooring and furniture is too thick to be ignited before curtain fragments burn out. (Thomas Goodale, The Ignition Hazard to Urban Interiors During Nuclear Attack due to Burning Curtain Fragments Transported by Blast, URS Research Corp., San Mateo, California, report URS-7030-5, 1971.)

There are lots of simple countermeasures against thermal ignition in the threat of a nuclear attack. For rooms containing ignitable items like beds, upholstered furniture, or rugs: choose light-coloured curtains, paint a mixture of flour and water on to the inside of windows with a potential view of the fireball, or even better simply tape sheets of aluminium cooking foil over those particular windows. For other rooms and offices: dispose of loose combustible materials like newspapers, magazines and trash, and place in the rooms buckets filled with water or sand to use to extinguish fires before they can spread. Blankets soaked with water are useful to beat out tindering fires before they spread.

Lynn Eden goes on (pages 218-9):

'Many studies followed, but the results were inconclusive. One experiment undertaken in the spring of 1973 ... subjected twenty pans of burning fuel to blast ... "no fire at any of the three stations was extinguished by the shock wave". ... Some experiments ... appeared to bear out Goodale's findings, others did not.'

This is dishonest because burning liquid in pans involves the circulation of hot convection currents of liquid with a much higher specific heat capacity (heat retaining ability) than air. Solid fuels only circulate hot gases, which have a low specific heat capacity and so are easily blown out by a blast of relatively cool air. But burning liquid is totally different and can be much harder to extinguish once the liquid is heated to ignition temperature by convection currents within it. This has nothing to to with the extinguishing nature of the blast wave on burning solid fuels: it is patiently and fundamentally dishonest to compare experiments on dissimilar phenomena and then claim that they are contradictory so that those which support civil defence can be ignored as 'inconclusive'. That is just fact ignoring pseudoscience, a political dodge with no place in fact-based science.

Lynn Eden states on page 219:

'... In the "doughnut hole", the area immediately surrounding the detonation, collapsed strustures would prevent fires from burning or would extinguish incipient fires; farther away, fires would burn vigorously. ... at Hiroshima ... there was no "hole" near the detonation, nor was there evidence of such a hole at Nagasaki.'

This is a dishonest 'comparison' because Hiroshima and Nagasaki were wood frame cities, not brick and concrete. The few brick and concrete buildings survived in each city, often with minor damage. It is dishonest for Lynn Eden and her sources like Postol and Brode to ignore the fact that brick and concrete can't burn but wood can burn. The May 1947 U.S. Strategic Bombing Survey report on Hiroshima, pp. 4-6:

‘Six persons who had been in reinforced-concrete buildings within 3,200 feet [975 m] of air zero stated that black cotton black-out curtains were ignited by flash heat... A large proportion of over 1,000 persons questioned was, however, in agreement that a great majority of the original fires were started by debris falling on kitchen charcoal fires... There had been practically no rain in the city for about 3 weeks. The velocity of the wind ... was not more than 5 miles [8 km] per hour....

‘The fire wind, which blew always toward the burning area, reached a maximum velocity of 30 to 40 miles [48-64 km] per hour 2 to 3 hours after the explosion ... Hundreds of fires were reported to have started in the centre of the city within 10 minutes after the explosion... almost no effort was made to fight this conflagration within the outer perimeter which finally encompassed 4.4 square miles [11 square km]. Most of the fire had burned itself out or had been extinguished on the fringe by early evening ... There were no automatic sprinkler systems in building...’

The British Home Office Manual of Civil Defence, Vol. 1, Pamphlet No. 1, Nuclear Weapons, 2nd edition, 1959, states that the 'main fire zone' in a British brick built city will not exist within the radius of peak overpressure 11 psi because the rubble will exclude air and prevent significant fires within that radius. It specified four damage zones:

A - 11 psi (75 kPa) peak overpressure: complete destruction of ordinary houses, so brick rubble extinguishes fires.

B - 6 psi (40 kPa) peak overpressure: brick walls cracked or demolished, houses irreparably damaged, streets blocked with debris until cleared with mechanical aids.

C - 1.5 psi (10 kPa) peak overpressure: doors and roofs smashed in addition to broken windows and tiles blown off roofs.

D - 0.75 psi (5 kPa) peak overpressure: light damage, just glass and tiles.

Russian nuclear test based civil defence data indicated that brick houses do not burn at overpressures above 7 psi because the rubble prevents fires, as quoted Cresson H. Kearny, Nuclear War Survival Skills, Updated and Expanded 1987 Edition, Oak Ridge National Laboratory/Oregon Institute of Science and Medicine, 1987, Chapter 1:

'Soviet propagandists promptly exploited belief in unsurvivable "nuclear winter" to ... demoralize their enemies. Because raging city firestorms are needed to inject huge amounts of smoke into the stratosphere and thus, according to one discredited theory, prevent almost all solar heat from reaching the ground, the Soviets changed their descriptions of how a modern city will burn if blasted by a nuclear explosion. ... [before nuclear winter hype in 1983] Russian scientists and civil defense officials realistically described ... the burning of a city hit by a nuclear weapon. Buildings in the blasted area for miles around ground zero will be reduced to scattered rubble - mostly of concrete, steel, and other nonflammable materials - that will not burn in blazing fires. Thus in the Oak Ridge National Laboratory translation (ORNL-TR-2793) of Civil Defense, Second Edition (500,000 copies), Moscow, 1970, by Egorov, Shlyakhov, and Alabin, we read: "Fires do not occur in zones of complete destruction . . . that are characterized by an overpressure exceeding 0.5 kg/cm2 [7 psi peak overpressure], because rubble is scattered and covers the burning structures. As a result the rubble only smolders, and fires as such do not occur." ... No firestorm has ever injected smoke into the stratosphere, or caused appreciable cooling below its smoke cloud.

'The theory that smoke from burning cities and forests and dust from nuclear explosions would cause worldwide freezing temperatures was conceived in 1982 by the German atmospheric chemist and environmentalist Paul Crutzen, and continues to be promoted by a worldwide propaganda campaign. This well funded campaign began in 1983 with televised scientific-political meetings in Cambridge and Washington featuring American and Russian scientists. A barrage of newspaper and magazine articles followed, including a scaremongering article by Carl Sagan in the October 30, 1983 issue of Parade, the Sunday tabloid read by millions. The most influential article was featured in the December 23,1983 issue of Science (the weekly magazine of the American Association for the Advancement of Science): "Nuclear winter, global consequences of multiple nuclear explosions," by five scientists, R. P. Turco, O. B. Toon, T. P. Ackerman, J. B. Pollack, and C. Sagan. Significantly, these activists listed their names to spell TTAPS, pronounced "taps," the bugle call proclaiming "lights out" or the end of a military funeral.

'Until 1985, non-propagandizing scientists did not begin to effectively refute the numerous errors .... A principal reason is that government organizations, private corporations, and most scientists generally avoid getting involved in political controversies ... Stephen Schneider has been called a fascist by some disarmament supporters for having written "Nuclear Winter Reappraised," according to the Rocky Mountain News of July 6, 1986. Three days later, this paper, that until recently featured accounts of unsurvivable "nuclear winter," criticized Carl Sagan and defended Thompson and Schneider in its lead editorial, "In Study of Nuclear Winter, Let Scientists Be Scientists." In a free country, truth will out - although sometimes too late to effectively counter fast-hitting propaganda.'

DPA Attack Environment Manual: Chapter 3, What the Planner Needs to Know about Fire Ignition and Spread, U.S. Department of Defense, report CPG 2-1A3, June 1973, Panels 3 and 5:

'Of course, hardly anyone lives in an area where they would be certainly exposed to thermal radiation ... There would be buildings, trees, hills ... Virtually any opaque material will serve to shield against the thermal pulse. ... nearly all of the radiation would be shielded out by objects before they are damaged or moved by the blast wave. ... tinder fuels do not usually contain sufficient energy by themselves to cause a sustained fire. What is needed is a "fuel array" containing both tinder and other burnables. ... Hardly anyone puts black curtains at their windows. In the thousands of sites that have been surveyed, none have been found. Crumpled newspaper and dry leaves are found in urban areas but, like people in the streets, they are very often not in a position to "see" the fireball and rarely are they located with other burnables to form a sufficient fuel array to cause a building fire. ... Some fire analysts consider only upholstered furniture and beds as the fuel arrays of significance. About 35 to 40 calories per square centimetre are required for ignition by a 5-Mt weapon.'

Curtains and drapes should be closed across windows in an impending nuclear attack, to shield beds and upholstered furniture from thermal radiation. Ignition of curtain fragments are easily stamped or doused out. This occurred at Hiroshima, where the main source of fires was the overturning of charcoal braziers in wooden houses by the blast wave.

John McAuliffe and Kendall Moll studied the blast wave role in starting fires in their 224 pages long report, Secondary Ignitions from Nuclear Attack, Stanford Research Institute, California, report AD625173, July 1965. They found that flying debris and building collapse data on fire ignition was available from the Hiroshima and Nagasaki nuclear bombings, high explosive disasters such as the massive Texas City ship explosion in 1947, World War II bombings, earthquakes and tornadoes. They concluded that for American cities (which don't use Japanese charcoal cooking braziers in indoors in homes filled with paper screens and bamboo furnishings), there are only 0.006 fires ignited by the blast wave per 1,000 square feet of floor area damaged by peak overpressures of 2 psi or more. This is approximately 1% ignition of typical American homes, one fire in every three blocks, or 80 fires per square mile in an area which is 25% builtup with 2-story buildings. Electrical wiring and gas piping were considered equally vulnerable. (Actually, this will be an overestimate because the source-region cable pick up of light-speed EMP current surges will automatically shut down transformers within a few microseconds of a surface burst or low air burst on a city; power stations and substations may be ignited by the EMP, but it will prevent secondary ignitions of electrical fires by blast wave debris in homes.)

A theoretical study of the combined effects of both primary thermal ignition of American homes by thermal radiation and also blast wave effects in extinguishing most of those fires but causing some secondary fires by damaging electrical and gas installations (they ignored the role of EMP) is the 97 pages long report by R. K. Miller et al., Analysis of Four Models of the Nuclear-Caused Ignitions and Early Fires in Urban Areas, the Dirkwood Corporation, New Mexico, report AD 716807, August 1970. This report used a combination of computer models to show that a 5 megaton surface burst on Detroit would ignite 2% of buildings at 8 miles from ground zero where the peak overpressure was 2 psi, rising linearly to a maximum of 10% of buildings at 5 miles (and within 5 miles) where the peak overpressure was 5 psi or more.

The poorly researched 1979 U.S. Congressional Office of Technology Assessment report The Effects of Nuclear War ignorantly used these figures of 2% ignition at 2 psi and 10% at 5 psi without understanding that they include thermal radiation effects and therefore do not scale with peak overpressure!

Another study of fires ignited in Detroit by a 5 Mt burst is Arthur N. Takata and Frederick Salzberg, Development and Application of a Complete Fire-Spread Model: Volume II, IIT research Institute, Chicago, report AD684874, June 1968, found that 3.8% of all buildings could be ignited initially, but that firespread could burn down many more if initial ignitions were not stamped out. Radiation from a burning wooden building emits about 4 cal/cm2/sec, and it takes only 0.4 cal/cm2/sec to ignite wood, so whenever another wooden house occupies more than 10% of the field of view of a burning house, it will be ignited. (Takata and Salzburg note that in the Darmstadt fire of 11 September 1944, where firebrands were negligible, thermal radiation from burning wooden houses caused a 72% probability of igniting immediately adjacent houses, a 50% probability of igniting houses 8 metres away, and a 10% probability of igniting houses 12 metres away.)

This short-ranged radiation firespread mechanism could nearly double the number of house ignitions in Detroit over the first hour, from 3.8% to 6.5% of houses burning at one hour post attack. After an hour, firebrands from burning houses would start to seriously contribute to the ignition of fires at much greater distances than the heat radiation from burning wooden buildings, so by 3 hours 18% of buildings in Detroit could be burnt out, and by 28 hours the figure could rise to 50%. Unlike a firestorm, this would be a very slow process, like the Great Fire of London in 1666 where only 8 people were killed when 32,000 homes were burned over 1.8 km2, because the fire spread very slowly over 4 days; and the Chicago Fire of 1871 where only 50 people were killed when 17,500 homes burned over an area of 8.6 km2 over a period of 3 days. (Wind carried burning firebrands from the Great Baltimore Fire of 1904 caused fires to wooden houses at distances of up to 800 metres downwind. Landing on wooden roofs, they are very difficult to deal with when the fire brigade is preoccupied with the existing fire zone.)

In Hiroshima, the secret May 1947 report of the U.S. Strategic Bombing Survey (Fig 5-IX) found that for wooden houses, the probability of one burning house igniting another by firebrands is 50% for a separation distance of 26 m, and shows (Fig 4-IX) that the risk of fire spread is 50% where 21% of the ground area is covered by wooden houses or 32% of the ground area is covered by industrial buildings.

‘Considerable war-time experience in the UK established beyond doubt that the chance of a continuing fire in an ordinary British house spreading and involving another house is less than 40%.’ – George R. Stanbury, The number of fires caused by nuclear attack, British Home Office, Scientific Adviser’s Branch, report SA/PR 90, 1965.

Many American buildings are wood-frame. For the brick and concrete type buildings that prevail in Britain, the Home Office Scientific Advisory Branch Scientific Advisers' Operational Handbook, Scottish Home and Health Department, H. M. Stationery Office, Edinburgh, 1979, states on page 39:

'The density of initial ignitions in the main fire zone, for UK houses, is likely to be very roughly one house in thirty, with a fire-spread factor of about 2 [i.e., each initial ignition will on average ignite one other building by thermal radiation, wind blown convection flames, and hot burning firebrands]. About one house in fifteen is expected to become burnt out. This situation would not constitute a "firestorm" or "mass fire", and the number of fire casualties should be small.'

Firestorms have always required at least 50% of buildings to be ignited. A 71 pages long report by Robert M. Rodden, Floyd I. John, and Richard Laurino, Exploratory Analysis of Fire Storms, Stanford Research Institute, California, report AD616638, May 1965, identified the following parameters required by all firestorms:

(1) More than 8 pounds of fuel per square foot (40 kg per square metre) of ground area. Hence firestorms occurred in wooden buildings, like Hiroshima or the medieval part of Hamburg. The combustible fuel load in London is just 24 kg/m2, whereas in the firestorm area of Hamburg in 1943 it was 156 kg/m2. The real reason for all the historical fire conflagrations was only exposed in 1989 by the analysis of L. E. Frost and E.L. Jones, ‘The Fire Gap and the Greater Durability of Nineteenth-Century Cities’ (Planning Perspectives, vol. 4, pp. 333-47). Each medieval city was built cheaply from inflammable ‘tinderbox’ wooden houses, using trees from the surrounding countryside. By 1800, Britain had cut down most of its forests to build wood houses and to burn for heating, so the price of wood rapidly increased (due to the expense of transporting trees long distances), until it finally exceeded the originally higher price of brick and stone; so from then on all new buildings were built of brick when wooden ones decayed. This rapidly reduced the fire risk. Also, in 1932, British Standard 476 was issued, which specified the fire resistance of building materials. In addition, new cities were built with wider streets and rubbish disposal to prevent tinder accumulation in alleys, which created more effective fire breaks.

(2) More than 50% of structures ignited initially.

(3) Initial surface winds of less than 8 miles per hour.

(4) Initial ignition area exceeding 0.5 square mile.

The fuel loading per unit ground area is equal to fuel loading per unit area of a building, multiplied by the builtupness fraction of the area. E.g., Hamburg had a 45% builtupness (45% of the ground area was actually covered by buildings), and the buildings were multistorey medieval wooden constructions containing 70 pounds of fuel per square foot. Hence, in Hamburg the fuel loading of ground area was 0.45*70 = 32 pounds per square foot, which was enough for a firestorm.

By contrast, modern cities have a builtupness of only 10-25% in most residential areas and 40% in commercial and downtown areas. Modern wooden American houses have a fuel loading of 20 pounds per square foot of building area with a builtupness below 25%, so the fuel loading per square foot of ground is below 20*0.25 = 5 pounds per square foot, and would not produce a firestorm. Brick and concrete buildings contain on the average about 3.5 pounds per square foot of floor area, so they can't produce firestorms either, even if they are all ignited.

On the night of 9-10 March 1945, 334 B-29 aircraft dropped 1,667 tons of high explosives (to open up buildings to allow incendiary bombs inside) and incendiaries on Tokyo, creating a firestorm which burned down 41 km2 or 15.8 square miles, killing more people than at Hiroshima (where only 4.7 square miles was burned down) or Nagasaki (where the valley geography meant that only 1.8 square miles burned down). These data come from the U.S. Strategic Bombing Survey report, The Effects of Atomic Bombs at Hiroshima and Nagasaki, 1946.

THE BOMBING OF HAMBURG AND HOW THE FIRESTORM WAS PRODUCED

London was bombed in 1940 by about 200 aircraft for 61 consecutive nights. Prime Minister Winston Churchill wrote in September 1940 that ‘The bombers alone will provide the means of victory’, but in August 1941 an analysis of British night-time bombing raids showed that only 10-33 % of British bombers dropped their bombs within 8 km of their targets, the lower (10 %) figure being due to heavy anti-aircraft artillery in Ruhr. In conclusion, it was decided that precision attacks on small targets by bombers were a waste of time, and cities would be targeted instead. Arthur Harris became chief of bomber command on 25 February 1942 and wanted to accumulate a vast number of aircraft and to pound Germany’s capital city, Berlin, into submission. In a filmed statement, Harris said: ‘There are a lot of people who say that bombing can never win a war. My answer to that is: it has never been tried yet, and we shall see.’

However, Churchill rejected Harris’ demand to concentrate on Berlin. Churchill then nick-named Harris ‘Bomber’ (Arthur ‘Bomber’ Harris) and personally instructed him to bomb other German cities, such as Dresden, to support the Russian attack on Germany. On 14 February 1942, bomber command had received a directive stating: ‘the primary object of your operations should now be focussed on the morale of the enemy civil population and in particular, of the industrial workers.’

George R. Stanbury, the Home Office scientist who conducted Civil Defence research int fallout protection at Monte Bello for Operation HURRICANE, Britain’s first nuclear test in 1952, explains in detail how the Hamburg firestorm was produced in his classified article, ‘The Fire Hazard from Nuclear Weapons’, Fission Fragments, Scientific Civil Defence Magazine, Home Office, London, No. 3, August 1962, pp. 22-6, British Home Office, Scientific Adviser’s Branch, originally classified Restricted:


Above: effect of the Hamburg firestorm.

'We have often been accused of underestimating the fire situation ... we are unrepentant in spite of the television utterances of renowned academic scientists who know little about fire. ... Firstly ... the collapse of buildings would snuff out any incipient fires. Air cannot get into a pile of rubble, 80% of which is incombustible anyway. This is not just guesswork; it is the result of a very complete study of some 1,600 flying bomb [V1 cruise missile] incidents in London supported by a wealth of experience gained generally in the last war. Secondly, there is a considerable degree of shielding of one building by another in general. Thirdly, even when the windows of a building can "see" the fireball, and something inside is ignited, it by no means follows that a continuing and destructive fire will develop. ... A window of two square metres would let in about 105 calories at the 5 cal/cm2 range. The heat liberated by one magnesium incendiary bomb is 30 times this and even with the incendiary bomb the chance of a continuing fire developing in a small room is only 1 in 5; in a large room it is very much less. Thus even if thermal radiation does fall on easily inflammable material which ignites, the chance of a continuing fire developing is still quite small. In the Birmingham and Liverpool studies, where the most generous values of fire-starting chances were used, the fraction of buildings set on fire was rarely higher than 1 in 20.



ABOVE: the heat flash radiation which causes the scorching is so unscattered or unidirectional that any shading from the fireball source stops it even if you are exposed to the scattered radiation from the rest of the sky: shadows still present in October 1945 in the bitumen road surface of Yorozuyo Bridge, 805 m SSW of ground zero, Hiroshima, pointed where the bomb detonated (U.S. Army photo).

'And this is the basis of the assertion that we do not think that fire storms are likely to be started in British cities by nuclear explosions, because in each of the five raids in which fire storms occurred (four on Germany - Hamburg, Darmstadt, Kassel, Wuppertal and a "possible" in Dresden, plus Hiroshima in Japan - it may be significant that all these towns had a period of hot dry weather before the raid) the initial fire density was much nearer 1 in 2. Take Hamburg for example:

'On the night of 27/28th July 1943, by some extraordinary chance, 190 tons of bombs were dropped into one square mile of Hamburg. This square mile contained 6,000 buildings, many of which were [multistorey wooden] medieval.

'A density of greater than 70 tons/sq. mile had not been achieved before even in some of the major fire raids, and was only exceeded on a few occasions subsequently. The effect of these bombs is best shown in the following diagram, each step of which is based on sound trials and operational experience of the weapons concerned.

'102 tons of high explosive bombs dropped -> 100 fires
'88 tons of incendiary bombs dropped, of which:
'48 tons of 4 pound magnesium bombs = 27,000 bombs -> 8,000 hit buildings -> 1,600 fires
'40 tons of 30 pound gel bombs = 3,000 bombs -> 900 hit buildings -> 800 fires
'Total = 2,500 fires


'Thus almost every other building [1 in 2 buildings] was set on fire during the raid itself, and when this happens it seems that nothing can prevent the fires from joining together, engulfing the whole area and producing a fire storm (over Hamburg the column of smoke, observed from aircraft, was 1.5 miles in diameter at its base and 13,000 feet high; eyewitnesses on the ground reported that trees were uprooted by the inrushing air).

'When the density was 70 tons/square mile or less the proportion of buildings fired during the raid was about 1 in 8 or less and under these circumstances, although extensive areas were burned out, the situation was controlled, escape routes were kept open and there was no fire storm.'

Often people point to bits of glass melted by the firestorm in Hiroshima, and ignorantly claim it was a special effect of nuclear weapons. Alas, such melted glass occurred in the GreatFire of London, 1666, and it didn’t need a nuclear explosion:

‘Having stayed, and in an hour’s time seen the fire rage every way, and nobody, to my sight, endeavouring to quench it, but to remove their goods, and leave all to the fire; and, having seen it get as far as the Steelyard, and the wind mighty high, and driving it into the City; and everything, after so long a drought, proving combustible... So near the fire as we could for smoke; and all over the Thames, with one’s face in the wind, you were almost burned with a shower of fire-drops... took up, which I keep by me, a piece of glass of Mercers’ chapel in the street, where much more was, so melted and buckled with the heat of the fire like parchment.’ – Samuel Pepys (1633-1703), Great Fire of London, Diary, September 1666.

The Hamburg air raid be compared directly to the eventual policy of the U.S.A.F. bombers that were attacking Japan. The man who would pilot the nuclear bomber to Hiroshima, Paul Tibbets, who had been in Europe, advised General C. E. LeMay ‘many Japanese buildings were constructed of flammable material. Paper houses, we called them. “All you need to do is ‘area bomb’ these cities [using incendiaries],” I said.’ [P. W. Tibbets, The Tibbets Story, Stein & Day, 1978.]

LeMay took Tibbet’s advice and in his 1965 book (Mission with LeMay, Doublesday) explained why this was acceptable in World War II: ‘It was their system of dispersal of industry. All you had to do was visit one of those targets after we’d roasted it, and see the ruins of a multitude of tiny houses, with a drill press sticking up through the wreckage of every home. The entire population got into the act and worked to make those airplanes or munitions of war ... men, women, children.’

After the single Tokyo air raid killed 83,600 people on 10 March 1945, Dr Robert Oppenheimer predicted that a nuclear air raid at night (people indoors) would kill 20,000 people. Oppenheimer wanted the attack done at night to prevent women and children receiving flash burns in the daytime. He received a very cold reception from people like LeMay, owing to the insignificance relative to conventional air raids. Oppenheimer then began to sell the nuclear bomb as a thermal and nuclear radiation killer, instead of a blast device to be used at night.

Colonel Paul Tibbets was instructed by LeMay to ignore Oppenheimer’s wish and only to drop the bombs in the daytime visually to prevent the risk of a serious radar aiming error. He maximised casualties by minimising warning (although this was done for the deliberate purpose of minimising the risk of serious anti-aircraft gun attacks on the bombing aircraft): for weeks before dropping the bombs, the cities that had been carefully spared incendiaries were daily flown over by weather and photographic aircraft. This was to prevent surprise when the plane carrying the bomb appeared. Tibbets recorded in his autobiography that this ‘would accustom the Japanese to seeing daytime flights of two or three bombers over their target ... we hoped they would be lulled into ignoring us, when we came to deliver the real thing ... air raid sirens would sound when we came overhead.’

This ‘lulling’ meant that many people outside would merely watch the planes without taking shelter, and receive serious facial burns and direct exposure to other effects. Nobody was vaporised; the skin burns were deep enough near ground zero to be lethal in combination with the nuclear radiation exposure. In the case of Hiroshima, the weather survey aircraft caused a night time air raid, and a final weather aircraft ahead of the nuclear bomber set off air raid alarms at 7:30 am (cancelled by an all clear at 8 am), before the nuclear armed bomber arrived at 8:15 am. Mrs Nakamuru, a widow with three children had only just arrived back home after the ‘all clear’ from the weather aircraft-caused alarm, as described by John Hersey in his 1946 book Hiroshima:

‘They reached home a little after 2:30 am and she immediately turned on the radio, which, to her distress, was just then broadcasting a fresh warning. When she looked at the children and saw how tired they were, and she thought of the number of trips they had made in the past weeks, all to no purpose, she decided that inspite of the instructions on the radio, she simply could not face starting out all over again.’ When the all clear sounded at 8 am, she lit her stove and started cooking rice. She was in a wood frame house 1,230 metres from ground zero: ‘everything flashed whiter than any white she had ever seen. She had taken a single step when something picked her up and she seemed to fly into the next room over the raised sleeping platform, pursued by parts of her house ...’ Others were burned when they looked up at the B-29 and received facial flash burns, some behind windows which resulted in glass fragment lacerations in addition.

Tibbets remarked in his autobiography, The Tibbets Story: ‘Of course, one hopes that civilians will have the good sense to seek protection in bomb shelters.’ If so, there would have been far fewer casualties, and less impact, and Tibbets admitted: ‘In the case of Hiroshima, I was to learn later that Eatherly’s weather plane ... had set off air raid sirens but, when nothing happened, ours were ignored.’ The Joint Commission for the Investigation of the Effects of the Atomic Bomb in Japan, Medical Effects of the Atomic Bomb in Japan (Oughterson and Warren, editors, McGraw-Hill, New York, 1956), found ‘there only about 400 people in the tunnel shelters [Nagasaki] which had a capacity of 70,000’ and that such people survived ‘even directly below the bomb.’ Describing the situation in Hiroshima, it stated:

‘Most of the people were at home preparing breakfast; consequently thousands of fires were burning in charcoal braziers. Only a few people were in modern buildings.’

DR HAROLD L. BRODE AND FIRESTORM ERRORS IN LYNN EDEN'S BOOK, 'WHOLE WORLD ON FIRE'

'At a range of more than 1 nautical mile [= 6,076 feet = 1,851 m = 1.15 statute mile], more than half the buildings [in Hiroshima] were gutted by fire. At that point, the peak overpressure of the nuclear blast wave was about 3 psi, and the fireball heat or thermal fluence was about 8 or 9 cal/cm2.'

- Dr Harold L. Brode and Dr R. D. Small, A Review of the Physics of Large Urban Fires, in The Medical Implications of Nuclear War, U.S. National Academy Press, 1986, page 79.

This correlation of thermal radiation to the firestorm radius is totally bogus, because no fires at that radius were ignited by thermal radiation! Some 100% of house fires at that radius were ignited by the blast wave overturning charcoal cooking braziers inside wooden houses filled with paper screens and bamboo furnishings. Dr Brode and Dr Small might as well have correlated the radius of the firestorm to the EMP field or to the mushroom cloud radius, for all the relation that there was between thermal radiation and the firestorm radius in Hiroshima. They neglected the physical mechanism entirely, and practised the worst form of pseudoscience.

Brode on page 84 states that 'Threshold ignition levels ... for common susceptible materials in an urban environment increase with yield roughly as ... 3.5Wkt0.113 cal/cm2. This gives 9 cal/cm2 for 5 Mt, when as we have seen it actually takes four times more energy to ignite beds and upholstry in a sustained way which won't be blown out by the blast or die out without spreading to the rest of the room, even when the window can 'see' the fireball:

'About 35 to 40 calories per square centimetre are required for ignition by a 5-Mt weapon.' - DPA Attack Environment Manual: Chapter 3, What the Planner Needs to Know about Fire Ignition and Spread, U.S. Department of Defense, report CPG 2-1A3, June 1973, Panels 3 and 5.

Lynn Eden, who had numerous interviews and discussions with Dr Brode since the late 1980s, is also duped entirely by this outrageous anti-civil defence lie in her 2004 book Whole World on Fire: Organizations, Knowledge, and Nuclear Weapons Devastation, where she writes on page 120:

'At Hiroshima, the perimeter of mass fire ... occurred about one mile from the detonation ... at this distance, the thermal fluence deposited was estimated at 10 cal/cm2 ... The deposition of thermal fluence of 10 cal/cm2 is the basic measure used in much of Theodore Poston's published work on fire damage ...'

Theodore Poston in his ignorant paper 'Possible Fatalities from Superfires following Nuclear Attacks in or Near Urban Areas', in the 1986 U.S. National Academy of Sciences book The Medical Implications of Nuclear War, assumes falsely that brick and concrete cities can burn like the small areas of medieval German cities and like Brode and Small, he simply ignores the mechanism for the firestorm in Hiroshima which had nothing to do with thermal radiation but was just due to overturned breakfast charcoal braziers. Theodore Poston also falsely complains that wooden houses exposed to nuclear tests didn't burn because they had white paint on them and shutters over the windows. That discredits Theodore Poston's whole anti-civil defence countermeasure tirade by actually PROVING the value of simple civil defense; but actually if you open your eyes, you find that most wooden houses are painted white, and in a real city - unlike the empty Nevada desert - few windows will have a line of sight to the fireball anyway!

The pseudoscientific fanatical thuggery against civil defence countermeasures to nuclear terrorism must be deplored. (Another basic scientific error Lynn makes is trying to use firestorm data from incendiary phosphorus bombing in humid weather to discredit the fact that thermal ignition depends on humidity! Unlike nuclear weapons thermal radiation which demands dry tindering to cause ignition, phosphorus is actually ignited by water! You must never pour water on a phosphorus bomb, or it will flare up. Ignorance of such basic chemistry is lethal.)

Brode and Small make the worst error of all when they state on page 94: 'Despite a well-organized German civil defense, firefighting, rescue operations, and emergency medical aid were severely limited in many of the fires and totally ineffective in the intense fire storms.'

They incorrectly ignores all the evidence that the civil defence operations were hampered by the extended period of air raid bombing, which did not occur at Hiroshima or Nagasaki where only a single bomb was dropped. They ignorantly take no account or make any mention whatsoever of all the studies done on the efficient, extremely easy and effective firefighting that readily saved buildings near Hiroshima's ground zero, well within the firestorm area, reported by the U.S. Strategic Bombing Survey. For example, the Bank of Japan, Hiroshima branch, was a 3-story reinforced concrete frame building at just 400 m from ground zero. There were no initial ignitions at all by either blast or thermal radiation. However, 1.5 hours afterwards a a firebrand started a fire in a room on the second floor. The survivors in the building simply extinguished the fire with buckets of water! Duh! Hiroshima in the very middle of the intense fire storm?! Buckets of water? Yes. They simply put the fire out. Later another firebrand ignited the third floor, and the survivors this time ran out of water and just shut the doors and allowed it to burn out. The fire did not spread to the lower floors.

This incident is explained in panel 26 of the DPA Attack Environment Manual: Chapter 3, What the Planner Needs to Know about Fire Ignition and Spread, U.S. Department of Defense, report CPG 2-1A3, June 1973, which adds that the Geibi Bank Company in the firestorm area of Hiroshima also survived the bomb with no thermal or blast ignitions: 'However, at about 10:30 A.M., over 2 hours after the detonation, firebrands from the south exposure ignited a few pieces of furniture and curtains on the first and third stories. The fires were extinguished with water buckets by the building occupants. Negligible fire damage resulted.'

It is either incompetent or else dishonest of Dr Harold L. Brode and Dr R. D. Small to try to discredit civil defense countermeasures against firestorms in nuclear attack by giving the false example of German bombing raids and totally ignoring the experiences of the Hiroshima firestorm to nuclear warfare (below).



Cover-up of the Hiroshima firestorm mechanism by suppression of the 1947 secret six volumes U.S. Strategic Bombing Survey report, which gives statistical evidence on the cause of the fire ignitions, contradicting the deceptions in the 1946 unclassified single volume U.S. Strategic Bombing Survey report on Hiroshima and Nagasaki, and The Effects of Nuclear Weapons

“The report summarizes the results of a detailed data reduction and casualty study made on over 35,000 persons who were subjected to the nuclear attack on Hiroshima and Nagasaki, Japan, in 1945. Both graphical and tabular presentations are made of pertinent data to show that an excellent base exists for more reliable conclusions of a wider variety than have heretofore been available. Total mortality and total injury curves are given as well as injury curves by type (blast, thermal, and initial nuclear) for thirteen shielding categories ...” - L. Wayne Davis, William L. Baker and Donald L. Summers, Analysis of Japanese Nuclear Casualty Data, Dirkwood Corporation Albuquerque DC-FR-1045 (1966), Abstract.

As we have explained before, the American Government has never published the originally secret 1947 six volumes of its Strategic Bombing Surveys of the nuclear bombed cities, Hiroshima and Nagasaki. The report on Hiroshima includes surveys of survivors (50% of people on the ground floors of concrete buildings at 0.12 mile, and a similar proportion of people outside and standing facing the aircraft at 1.3 mile range) which prove that the source of the firestorm wasn't thermal radiation (which only started a few fires in black coloured air raid “black-out curtains”, used to screen home lights from being seen by bombers above the cities), but the blast wave overturning thousands of paper screens and charcoal cooking braziers in wood frame dwelling homes.

Did Samuel Glasstone, Philip J. Dolan, and Harold L. Brode (the main compilers of the official American publications on nuclear weapons effects and capabilities, all of whom had security clearance) know this? Why didn’t they include this fact, which has massive implications not just for firestorms but also for “nuclear winter” (scare stories of climatic effects which were circulated by the friends of the Soviet Union in 1980s against President Reagan’s civil defense policies), which rely on thermal ignition over wide areas to cause fires?

TAPPS 1990 OIL REFINERY TARGETTING ASSUMPTION OF CONVENIENCE

President Reagan in 1982 was talking about civil defense for bolstering U. S. deterrence of 40,000 Soviet main battle tanks (ready to invade the West, take over the resources, and thus shore up the impending economic implosion of communism for another few decades), and that “survival talk” was what led Dr Carl Sagan and others to suggest everyone would be frozen by a nuclear winter in 1983. Then the fake “better red than dead” assumptions of the 1983 calculations were revealed. In 1985, Dr R. D. Small and Dr B. W. Bush of Pacific-Sierra Research Corp assessed the smoke from 4,100 megatons distributed as 2 warheads per target on 3,459 counter-force targets in forests and grassland areas (Science, v229, p465). They found the smoke output was 300,000 tons for a January attack and 3,000,000 tons for an August attack. These figures are 100-1,000 times lower than the guesses made by the “nuclear winter” hype of 1982-3, because the smoke is only 3% of the mass of vegetation burned (the rest is CO2 gas and cinders): “The amount varies seasonally and at its peak is less by an order of magnitude than the estimated threshold level necessary for a major attenuation of solar radiation.”

One of the original errors was overestimating the soot production by fire. The fraction of the mass burned that becomes smoke is only 1% for wood, 3% for vegetation, 6% for oil and 8% for plastic. So after some negative publicity about the “errors” in the “nuclear winter” hype, TTAPS (Turco, Toon, Ackerman, Pollack and Sagan) public relations experts in 1990 (Science, v247, p166) changed their targeting assumptions to make use of the figure of 6% soot emission by burning oil, by now assuming that 50% of primary petroleum stocks would be targets. I.e., they assumed that in a nuclear war, both sides would deliberately use nuclear weapons to create as much soot as possible by targeting oil refineries. This allowed them to go on with the hype. They simply ignored the lesson of Hiroshima, that firestorm soot is hydroscopic, absorbs moisture from the air, condenses in the cool air at high altitude, and falls back as rain within a few hours. But then, they ignored all of the civil defense lessons from Hiroshima, so why not also ignore the fate of the soot from fires after a nuclear explosion over an inflammable wood built city? They certainly were consistent in ignoring all of the effects of nuclear explosions in their political spin.

The basic equation for the fraction of sunlight absorbed during x metres of passage through a soot cloud containing s grams of soot per cubic metre is e-7xs. However, smoke is rapidly dispersed and removed by the atmospheric weather systems, wind and rain, as occurred at Hiroshima.

There has always been a “have your cake and eat it” approach to Hiroshima data by the anti-civil defense pro-terrorism lobby, which includes big name “physicists” who have political peace agendas similar to the 1930s peace agenda of Prime Minister Chamberlain towards Hitler (the myth that loving the dictator is a “more peaceful” policy than standing up to the dictator, which just convinces the dictator that you're unprepared to defend yourself and thus are offering yourself as a carpet to be trampled over). The situation is much as it was in 1954, when popular nuclear weapons lying propaganda designed to promote unilateral disarmament and surrender of Europe to communists led to an ill-informed belief that civil defence was no use, as the following quotation shows.




Fred N. Severud and Anthony F. Merrill, The Bomb, Survival, and You: Protection for People, Buildings, Equipment, Reinhold Publishing Corp., New York, 1954 (256 pp), pages 12, 29, 68, 69, 70, 88, 89, 90:

“This book was written in the face of a general apathy toward civil defense. We think that apathy is attributable to one of two things: either people are too overwhelmed by the size of the bomb to feel capable of coping with it, or they have been so frightened by it, subconsciously, that they are afraid to look civil defense and its implications full in the eye. ...

“Make what you will of our technical suggestions, but come away from this book understanding the real threat and the real effect potentialities of atomic warfare, not the stuff that is so luridly treated in the popularizations which have been frightening the public for the last eight years. We want the reader to be able, calmly and coolly, to appraise the atomic explosion just as he would any other abnormal structural loading.

“... it is only recently that the two three-volume reports of the United States Strategic Bombing Survey on Hiroshima and Nagasaki have been removed from the ‘Secret’ classification. These two reports, prepared by the Survey’s physical damage division, contain so much of interest to the structural specialist that we feel that even at this late date they are invaluable reference works. Unfortunately, publication of these originally ‘Secret’ documents in 1947 was limited to only a few hundred issues. They are so rare that they will never be available to the average engineer unless he has access to one of the very few archives which have these reports on file. To the ordinary technician these declassified reports will remain, to all intents and purposes, ‘Secret.’ ...

“We only wish we could present a thorough digest of the reports – 2,100 pages of text, charts, plans and excellent photographs of structural details. ...

“The morning of August 6, 1945, was a fine clear one in Hiroshima, a major Japanese city lying flat around the many-fingered Osa River delta. In the early hours there had been an air-raid alert, but by 7:30 the all-clear had sounded and the three B-29’s boring high over the city some 45 minutes later gave no one cause for alarm. They were assumed to be en route to some other destination. But at 8:15 one of them dropped an atomic bomb. ...

“Three days later, August 9, found a fine clear midsummer day bright over Nagasaki, a large industrial city whose topography differs considerably from Hiroshima in that the city lies principally along two river valleys which are separated from each other by a relatively high ridge. Early in the morning there had been an air raid alert which had been cancelled by 8:30. No all-clear was given, but less than 400 persons chose to remain in the tunnel shelters, which could accommodate 70,000. At 11:00 a.m. one of the two B-29’s dropped an atomic bomb over one of the city’s main valleys. ... no actual fire storm resulted and the irregular terrain provided shielding for many areas ...

Chapter V. Fire. Among the ashes and ruins of Hiroshima and Nagasaki the physical damage teams of the Strategic Bombing Survey found ample evidence upon which to predicate a whole set of fire protection fundamentals for urban areas vulnerable to atomic attack. Hiroshima, especially, provided what the Survey described as: ‘an excellent test target for the atomic bomb from a fire standpoint.’

“Everything about Hiroshima on August 6 seemed to contribute to the ideal conditions under which the fires caused by the bomb were able to develop … Here, on a flat plain, a densely built-up area of extremely combustible buildings … For three weeks there had been no rain. When the bomb went off, the blast damage immobilized most of the meagre fire department ...

How the fires started. A popular misconception is that the heat flash from the bomb did the trick, and this has led to the fanciful and blood-curdling illustrations of whole American cities wrapped in flame before the characteristic mushroom of the atomic blast has even begun to dissipate. This thriller approach is neither realistic nor intelligent. ...

“... In Hiroshima, the majority of fires were started by the secondary effect of the blast which collapsed upon city charcoal fires in dwellings and restaurants, caused short circuits, and brought down flammable debris upon fires already being used ...

“The Survey team questioned over a thousand persons in Hiroshima on how fires started. No more than a handful could point definitely to heat flash as a cause. One group of witnesses said that black cotton [air-raid “black-out”] curtains burst into flame at 3,200 feet from air zero (about 2,000 feet from ground zero). ... In another instance a piece of rice paper caught fire on a desk but failed to ignite heavier paper under it.”



The Media and the Firestorm “Nuclear Winter” Soot Propaganda

One of the Scientific American’s Cold War publishers, Gerard Piel, had a long history of lying and publishing lies about fires from nuclear weapons to attack civil defense readiness, just as his predecessors did in Britain during the 1930s (which made the Prime Minister appease Hitler, encouraging him to start WWII). Typical example:

“A heading in one recent report concerned with effects of nuclear detonations reads, ‘Megatons Mean Fire Storms,’ and the report predicts that a 20-megaton nuclear burst is sure to produce a 300-square mile fire storm. [Reference: Gerard Piel (then the anti-civil defense publisher of the Scientific American), ‘The Illusion of Civil Defense,’ published in the Bulletin of the Atomic Scientists, February 1962, pp. 2-8.] The report further states that blastproof bomb shelters afforded no protection in World War II fire storms, and the reader is left to conclude that vast fire storm areas in which there will be no survivors are an assured consequence of future nuclear attacks. ... the 40,000-50,000 persons killed by the fire storm at Hamburg constituted only 14 to 18 percent of the people in the fire storm area and 3 to 4 percent of Hamburg's total population at the time of the attack. ... Two of three buildings in a 4.5 square mile area were burning 20 minutes after the incendiary attack began at Hamburg, and similar figures were reported for other German fire storm cities.”


- Robert M. Rodden, Floyd I. John, and Richard Laurino, Exploratory Analysis of Fire Storms, Stanford Research Institute, AD616638, 1965, pages 1, 5.

Media lying about the thermal ignitions (leading to lies about firestorms and nuclear winter caused by the soot of such fires blocking sunlight) can be traced back to the secret classification of the full three-volume 1947 report on Hiroshima by the Strategic Bombing Survey, which was edited out of the brief single volume "summary" that the openly published a year earlier, 1946. Here is the key revelation (originally ‘secret’ May 1947 U.S. Strategic Bombing Survey report on Hiroshima, pp. 4-6):

‘Six persons who had been in reinforced-concrete buildings within 3,200 feet [975 m] of air zero stated that black cotton black-out curtains were ignited by flash heat... A large proportion of over 1,000 persons questioned was, however, in agreement that a great majority of the original fires were started by debris falling on kitchen charcoal fires ...There had been practically no rain in the city for about 3 weeks. The velocity of the wind ... was not more than 5 miles [8 km] per hour.... Hundreds of fires were reported to have started in the centre of the city within 10 minutes after the explosion... almost no effort was made to fight this conflagration ... There were no automatic sprinkler systems in building...’ [Emphasis added.]


What modern city is today built out of 1945 Hiroshima style wood frame houses with charcoal stoves amid bamboo furnishings and paper screens? Even Hiroshima is no longer built like that, it's a modern steel, concrete, and brick city and would not suffer a firestorm if a bomb dropped on it again. By the way, the "nuclear winter" from the Hiroshima fire storm blocked out the sun for 25 minutes (from burst time at 8:15 am until 8:40) in Hiroshima as shown by the meteorological sunshine records printed in Figure 6 (3H) of Drs. Ashley W. Oughterson, Henry L. Barnett, George V. LeRoy, Jack D. Rosenbaum, Averill A. Liebow, B. Aubrey Schneider, and E. Cuyler Hammond, Medical Effects of Atomic Bombs: The Report of the Joint Commission for the Investigation of the Effects of the Atomic Bomb in Japan, Volume 1, Office of the Air Surgeon, report NP-3036, April 19, 1951, U.S. Atomic Energy Commission (linked here). There were no reported casualties due to 25 minutes of sunlight deprivation.

So even where city firestorms have actually occurred, there was not a nuclear winter. What about the theoretical predictions that a nuclear attack on oil supplies will cause a nuclear winter, made by the founder of nuclear winter hype, Paul Crutzen? Saddam Hussein’s Iraqi army invaded Kuwait and set all of its oil wells on fire as it was driven back into Iraq by America in 1991.

Peter Aldhous, ‘Oil-well climate catastrophe?’, Nature, vol. 349 (1991), p. 96:

‘The fears expressed last week centred around the cloud of soot that would result if Kuwait’s oil wells were set alight by Iraqi forces ... with effects similar to those of the “nuclear winter” ... Paul Crutzen, from the Max Planck Institute for Chemistry in Mainz, has produced some rough calculations which predict a cloud of soot covering half of the Northern Hemisphere within 100 days. Crutzen ... estimates that temperatures beneath such a cloud could be reduced by 5-10 degrees C ...’


Dr Richard D. Small of Pacific-Sierra Research Corporation, California, responded in Nature, vol. 350 (1991), pp. 11-12, that 16,000 metric tons of actual soot is produced from 220,000 metric tons of oil burned every day, and anyway:

‘My estimates of the smoke produced by destruction of Kuwait’s oil wells and refineries and the smoke stabilization altitude do not support any of the purported impacts. The smoke is not injected high enough to spread over large areas of the Northern Hemisphere, nor is enough produced to cause a measurable temperature change or failure of the monsoons.’


It turned out that the nuclear winter hype was false, because even if you do somehow manage to start a firestorm in the modern world (the wooden medieval areas of Hamburg and Dresden weren't rebuilt with wood after they burned in firestorms), it simply doesn't produce a stable layer of soot in the stratosphere like the computer simulation. At Hiroshima the soot returned to the ground promptly because it is hydroscopic: it forms water droplets, rain. (It wasn't fallout: the firestorm took over 20 minutes to get doing, by which time the radioactive mushroom cloud had been blown miles downwind.) The most basic and direct rebuttal to firestorm extinction and nuclear winter is from the sunlight recorder and the factually undisputed evidence for the 100,000,000 megatons of TNT-equivalent 10-km diameter K-T impact event of 65 million years ago, where you had a comet impact explosion with with an energy 6,250,000,000 times greater than Hiroshima, creating a 180 kilometres diameter crater at Chicxulub on the coast of Yucatan, Mexico, burning rainforests and creating a smoke and dust-induced winter which killed off enormous cold-blooded dinosaurs but not warm-blooded mammals or many plants. End of doomsday propaganda!

JANE M. ORIENT, M.D., “Disaster Preparedness, An International Perspective”, Annals of Internal Medicine, v103 (1985), 937-940:

“If the amount of smoke assumed in the “nuclear winter” report (Science, v222, 1983, pp1283-92) were decreased by a factor of 2.5, the climatic effect would probably be trivial. In considering the actual terrain that surrounds most likely targets, the probable type of explosions (ground bursts against hardened military facilities), the overlapping of targets, and conditions that could reduce the incendiary potential of the thermal pulse, critics of the report believe that the quantity of smoke from nonurban fires has probably been overestimated by at least a factor of ten (Cresson Kearny, Fire Emissions and Some of Their Uncertainties, Presented at the Fourth International Seminar on Nuclear War, Erice, Sicily, August 19-24, 1984). Rathjens and Siegel (Issues in Science and Technology, v1, 1985, pp123-8) believe there would likely be four times less smoke and eight times less soot from cities than estimated in the National Research Council study.”


Professor Brian Martin, “Nuclear winter: science and politics,” Science and Public Policy, Vol. 15, No. 5, October 1988, pp. 321-334:

Politics enters science

“More than ‘pure science’ is involved when a researcher decides that a particular area is ‘scientifically interesting’. Many features of wider society influence the process of choice of research, including the availability of funding, possible applications, technological infrastructure, ideas prevalent in society and the social position of scientists. Each of these factors played a role in turning nuclear winter into a priority research area in the 1980s. The resurgence of the peace movement in the early 1980s provided fertile ground ... the editors of the environmental journal Ambio, published by the Swedish Academy of Sciences, planned a special issue in 1982 to cover the effects of nuclear war. Paul Crutzen was asked to deal with the effects of nuclear war on the atmosphere for this issue. Crutzen in his Ph.D. did pioneering work in showing the important effect of nitrogen oxides in regulating the amount of ozone in the stratosphere. ... In 1981 journalist Jonathan Schell wrote a series of articles in the New Yorker arguing that nuclear war could cause extinction of human life, principally through destruction of stratospheric ozone. Schell's articles, made into a book, were inspired by the burgeoning peace movement and in turn were widely taken up by it. Yet by the time he made his argument, the basis for massive ozone destruction by nuclear weapons had largely evaporated. This is what Crutzen and his collaborator John Birks found in 1982 as they ran their computer models dealing with stratospheric ozone to determine the effects of a nuclear war. Because the large multimegatonne nuclear bombs deployed in the 1950s were being replaced by larger numbers of smaller warheads, not as much nitrogen oxides would be lofted far up into the stratosphere. Crutzen and Birks’ model did not predict a significant reduction in stratospheric ozone using the Ambio reference scenario.

“Crutzen and Birks each over the years had examined a wide range of physical and chemical processes which could affect the dynamics of the atmosphere. As they dealt with the problem of the effects of nuclear war on the atmosphere, they happened to think about the smoke released by fires caused by nuclear attacks. Quick calculations showed that the smoke could absorb a large fraction of sunlight, leading to “twilight at noon”. In short order they included this in their now-famous paper for Ambio. The Crutzen-Birks paper was immediately taken up as heralding an important and hitherto unrecognised effect of nuclear war. The next step, to nuclear winter, was taken by Richard Turco, Owen Toon, Thomas Ackerman, James Pollack and Carl Sagan, the so-called TTAPS group. Taking the Crutzen-Birks idea that smoke and dust from a nuclear war would block out sunlight, they calculated that this would lead to massive cooling at the earth's surface ... The nuclear winter idea was spread to a highly receptive audience, including the peace movement, the mass media and much of the general population. ...

“Turning now to the actual research: does the science of nuclear winter embody in any way assumptions about politics? ... Targeting. The TTAPS paper uses a baseline case of 5000 megatonnes (MT), supplemented by a wide range of other scenarios which also lead to nuclear winter effects. Though in general terms some of the scenarios appear reasonable, no detailed strategic rationale is offered for any of them. A cynic might say that the key characteristic of the scenarios is that they produce sufficient smoke or dust to produce nuclear winter. ... Extinction. Ehrlich et al. itemise all sorts of disasters from nuclear war. For example, they raise the issue of decreases in stratospheric ozone and resulting increases in ultraviolet (after the smoke and dust clears), not noting that changes in the size of warheads have made this threat much less serious. They add up a set of hazards to conclude that human extinction may occur, without explaining precisely how everyone could die.

“While listing many dangers from nuclear war, they do not mention factors which might ameliorate the problems. For example, food shortages due to crop failures are highlighted, plus difficulties in transporting stored food to population centres. For the rich countries, there is no mention of changing from a meat diet to a grain diet or of reducing caloric intake, which together would extend food reserves by a large factor. For Third World countries, they emphasise dependence on imports of food from rich countries. They do not mention the exports of food to rich countries, nor the high level of cash cropping for export to industrialised countries, which could be replaced by food crops for local consumption. The suggestion that extinction of human life could occur is made without considering any counterexamples. For example, consider Tasmania. As an island in the southern hemisphere, nuclear winter effects would be minimised. It has large hydropower capacity for providing heat and power, and the large sheep population could help tide the modest human population through a failed harvest. Such examples are not addressed by Ehrlich et al. The possibility of extinction is not even discussed in the text of Ehrlich et al.’s paper. It is only raised in the summary and conclusion. The combination of these assumptions leads to concentration on worst cases. The selection of results for key diagrams and abstracts makes the drawing of certain policy implications much easier. In other words, the TTAPS and Ehrlich et al. papers are not “value-neutral” pieces of research, but “push” certain conclusions on readers through technical assumptions in model construction, selection of evidence and highlighting of results ... the models have been criticised for not adequately taking account of the coagulation of soot, the raining out of soot and dust, and gaps in soot clouds in the first few weeks after fires. ...

“In the debate over nuclear power, there were few scientist critics, at least in early years. The proponents claimed sole authority on nuclear issues, and dismissed critics as incompetents and malcontents. The anti-nuclear movement was seen as lacking any technical credibility. ... In the nuclear winter controversy, the best example of this dynamic is seen in the response to criticisms by Russell Seitz. Seitz is an Associate of the Harvard University Center for International Affairs where earlier he was a Visiting Scholar. While he has presented technical criticisms of nuclear winter on several occasions, he really raised the hackles of nuclear winter scientists with an article in The National Interest entitled “In from the cold: ‘nuclear winter’ melts down”. In this article he not only criticises the scientific basis for nuclear winter, but also systematically argues that the whole nuclear winter argument was politically motivated: “a politicization of science sufficient to result in the advertising of mere conjecture as hard fact”. Seitz points out the role of the peace movement in triggering consideration of nuclear winter. He argues that the TTAPS model is filled with assumptions which give results which the researchers wanted to achieve: “worst-case analysis run amok”. ... After a discussion of the media promotion of nuclear winter, Seitz turns to the substantive scientific criticisms, such as Schneider and Thompson's reevaluation that the effect would better be called “nuclear autumn”. Seitz ... suggests that nuclear winter is virtually a conspiracy by supporters of Western peace movements ...

“... to even raise the issue of political factors influencing nuclear winter research would be damaging to the scientific objectivity claimed for the work. It is therefore not surprising that the nuclear winter proponents have not presented their own version of the interplay between science and politics.”


Update: for a full account of the 1960s origins of "nuclear winter" myth see later blog post linked here, which explains that Dr Tom Stonier published a book called Nuclear Disaster in America in 1963, predicting a nuclear winter "ice age" in chapter 12, "Ecological Upsets: Climate and Erosion." He claimed: "If the detonation of a large number of surface bursts should lead to an ice age, then the distortion of nature would last for millennia." A watered-down version of this propaganda was simply restated with similarly false targetting assumptions (ignoring the terrorist threats from single nuclear explosions, judged more probable than an all-out nuclear war by the U. S. Army field manuals) plus expensive media hype by the public relations company TAPPS used in 1983 to attract the media to attend their lavish "Conference on the Long—Term Worldwide Biological Consequences of Nuclear War", in Washington, D.C. The editor of Nature, Dr John Maddox, in his editorial in 1983 (vol. 312, p. 593) called the ‘nuclear winter’ scandal from TAPPS ‘hype’ because they got publicity by means of handing over $50,000 to a public relations company (the funding came from the Kendall Foundation). This is how political pseudo-science is marketed via media hype, caveat emptor! Lacking this "public relations" funding, Stonier went unheard twenty years earlier. When the buildings of Hiroshima burned, and when forests burn, moisture is carried up in the atmosphere along with the soot. When the column of dusty, hot, humid air reaches cold air at high altitudes, the moisture condenses on to the soot, and you get black rain out. This occurred at Hiroshima: it wasn't contaminated with significant radioactivity because the firestorm only began 30 minutes after the explosion, by which time the airborne radioactive mushroom cloud had been blown many miles downwind from the firestorm area.

Vaporizing myths: J. E. Kester and R. B. Ferguson, Operation Teapot, Project 5.4, Evaluation of Fireball Lethality Using Basic Missile Structures

“Observations of the remains of towers and shielding material after detonation at several ground zeros indicate that large masses of material are not vaporized. Observations of the residue of the Smoky tower [44 kt bomb atop a 700 foot high steel tower] indicated that a very significant portion of that tower remained, including the upper 200 feet of steel. Another example similar to Shot Smoky was Shot Apple II [29 kt atop a 500 ft steel tower], Teapot Series. Even though the total yield of Shot Apple II was about [29 kt], the floor of the cab [housing the nuclear bomb itself, at the top of the tower] and the main tower support columns remained intact. The results of the Shot Fizeau [11 kt atop a 500 ft steel tower] tower melt studies (W. K. Dolen and A. D. Thornborough, Fitzeau Tower Melt Studies, Sandia report SC-4185, 1958, Secret) show that about 85 percent of tower material was accounted for after the detonation and that only the upper 50 feet of tower was vaporized. No melting occurred beyond 175 feet from the top of the tower although the fireball theoretically engulfed more than 400 feet of the tower.”

- Dr Kermit H. Larson, et al., Distribution, Characteristics, and Biotic Availability of Fallout, Operation Plumbbob, weapon test report WT-1488, ADA077509, July 1966, page 59.


J. E. Kester and R. B. Ferguson report in Operation Teapot, Project 5.4, Evaluation of Fireball Lethality Using Basic Missile Structures, WT-1134 (originally Secret – Restricted Data), AD0340137, that within the 23 kt Teapot-Met (Nevada, 15 April 1955, 400 ft steel bomb tower) although the bomb test steel tower was blown down, it was not vaporized and much survived despite having been engulfed by the fireball itself, as stated on page 30:

“... nearly 225 feet of the main support members of the shot tower were still intact and laid out radially from their original position.”


Page 116 of WT-1134 states that after the 2 kt Moth shot atop a 300 foot triangular tower on 22 February 1955: “The three tower legs were laid out approximately radially from their pre-shot positions. The longest tower leg found was about 200 ft long. The other two legs appeared to be about 150 ft long. All three guy cables were still attached ... A few large pieces of the tower, about 20 to 30-ft long, were strewn to ranges of about 200 feet.” It adds that after the 7 kt Tesla shot atop a 300 ft square tower on 1 March 1955: “the four tower legs ... were laid out radially from their original position ... The tower legs remained intact to lengths of about 125 feet. All four guy cables were still attached ...” The 43 kt Turk nuclear test was fired atop a 500 ft square tower, leaving 100 ft lengths of tower lengths on the ground (page 118). The 8 kt Bee shot atop a 500 ft tower failed to even knock down most of the tower (pages 120-1): “A large portion of this tower was still standing after the shot. ... It is estimated that at least 150 feet of the tower was essentially undamaged and standing erect with an additional 50 to 75 feet of the tower slightly melted and drooped over at the top.” The 14 kt Apple 1 shot atop a 500 ft square tower results (page 121): “The main support members of the shot tower still remained to lengths of about 150 feet with the top 25 to 50 feet being crushed and split ... Some of the legs remained attached to the base.” The 23 kt Met shot was atop a 400 ft square tower (pages 123-4): “About 225 feet of the tower legs were still intact with the top 25 to 50 feet being crushed, split and slightly melted ....”






Above: color photo shows the lower 200 feet surviving from the 300 ft steel tower of the 0.2 kt Ruth nuclear test in Nevada on 31 March 1953. The black and white photographs are from the 23 kt Teapot-Met nuclear explosion (Nevada, 15 April 1955) ablation tests by J. E. Kester and R. B. Ferguson, Operation Teapot, Project 5.4, Evaluation of Fireball Lethality Using Basic Missile Structures, WT-1134 (Secret – Restricted Data), AD0340137, which showed that at just 80 feet only the outer 0.4 inch of steel balls was ablated by the fireball.

The error in the popular myth that everything is vaporized in the fireball is that the cooling rate of the fireball is so great that there is literally not enough time for the heat to penetrate more than a thin surface layer before the temperature drops below melting point. Good heat conductors like steel are protected by ablation. A very thin surface layer of the material is vaporized, protecting the underlying material, just as occurs with thermal radiation striking wooden houses (Glasstone and Dolan, The Effects of Nuclear Weapons):





Above: beer bottles fused in the firestorm in Hiroshima, 2-3 hours after the explosion. Similar fused glass was found by Samuel Pepys after the Great Fire of London, when the wood-frame buildings burned down. At Hiroshima, the thermal pulse had no significant effect on transparent materials like glass, and it has no significant effect on wood, brick, concrete or steel. The firestorm occurred later, when fires combined after the overturning of charcoal cooking braziers and the ignition of black colored blackout curtains in wooden houses, neither of which is possible in modern cities. Unlike the 9/11 fires in the World Trade Centre buildings, nuclear bombs don't inject burning aviation fuel into buildings: the big buildings at Hiroshima and Nagasaki did not contain any fire sprinkler systems like modern city buildings.

The fireball vaporization myth and civil defense



The anti-civil defense league throughout the Cold War promoted the lie that Hiroshima and Nagasaki were "vaporized", that people who shadowed wooden panels or paint from scorching were "vaporized", and that in the event of a nuclear attack, everything will be "vaporized", so that duck and cover precautions are useless. This myth needs to be refuted in scientific detail before civil defense will be taken seriously.

Above: line-of-sight shadowing in Hiroshima (Glasstone and Dolan, 1977). What really angers people who are against terrorism is the the fact that the anti-civil defence lobby uses this evidence for pseudo-scientific purposes, claiming falsely that anything in Hiroshima and Nagasaki which cast a burns shadow was 'vaporized'. People who cast 'shadows' on otherwise burned materials were not vaporized, they were painfully burned, and if they had ducked and covered behind anything opaque, they wouldn't have been.

‘A soldier on picket duty at Nagasaki was vaporised by the explosion even though he was 3.5 km from the centre of the blast.’

- Myth promoted by physics Professors Tony Hey and Patrick Walters, The Quantum Universe, Cambridge University Press, 1989, p. 69.


The soldier was only subject to skin reddening because of the brief pulse, which even a leaf or a sheet of paper stopped. The wooden panel behind the person was slightly scorched where shielded by the person. Hey and Walters’ are unaware that it takes more energy to evaporate water (people are 70% water) than to burn dry wood! If the flash had been sufficient to ‘vaporise’ anyone, the wooden panel would have burned first, being less than 70% water! However, some physics professors are proud to promote pseudo-science like non-relativistic (first-quantization) quantum mechanics in preference to relativistic second quantization, just like the myth that a bomb can vaporize 70% water people and merely leave scorch marks on a wooden fence!

ABOVE: U.S. Army photo showing how a mere leaf of Fatsia japonica attenuated the heat flash enough to prevent scorching to the bitumen on an electric pole near the Meiji Bridge, 1.3 km range, Hiroshima. It didn't even vaporize the leaf before the pulse ended, let alone did it somehow ignite the wooden pole (most photos claiming to show thermal flash radiation effects in Hiroshima and Nagasaki purely show effects from the fires set off by the blast wave overturning cooking stoves, which developed 30 minutes to 2 hours later).

'Even blades of grass cast permanent shadows on otherwise badly scorched wood. The [Hiroshima nuclear bomb heat] flash lasted less time than it took the grass to shrivel.' - Chapman Pincher, Into the Atomic Age, Hutchinson and Co., London, 1950, p. 50.



Above: people in Hiroshima mainly died from combined flash burns and radiation exposure (data from: Dr Ashley Oughterson and Dr Shields Warren, Medical Effects of the Atomic Bomb in Japan, McGraw-Hill, New York, 1956). The graph shows the impact of any kind of light shadow (not nuclear radiation shielding) from the line of sight of the fireball to the person, on survival probability. Nuclear radiation interfered with burn recovery, turning mild superficial burns into a lethal source of infection when the white blood cell count was depressed during the recovery phase by the fact that the burns were accompanied by concurrent nuclear radiation exposure. Hiroshima’s wood-frame houses shielded the heat flash, as did vehicles, trees, hills, bridges, tunnels and clothing, and by removing thermal burns, nuclear radiation became survivable. Glass/debris impacts are also avoided by ducking down since the blast is delayed like thunder after lightning. Notice that ‘duck and cover’ action would have increased survival probability at 1.75-2.5 km by a factor of 5.8-5.9.

'Don't stand behind windows in an attack. First you will get burned and then you will have fine glass splinters driven into you very deeply within distances like 7 miles from a 1-megaton burst. ... Glass in any disaster like the Texas City disaster is one of the primary materials found in the normal home which can result in blinding and all other types of effects due to the flying small splinters of glass.'

- Dr Frank H. Shelton, Technical Director of U.S. Armed Forces Special Weapons Project, testimony to U.S. Congressional Hearings on the Biological and Environmental Effects of Nuclear War, 22-26 June 1959, page 41.

Although windows are just broken by the peak overpressure out to 25 miles from a 1 Mt surface burst, the hazard from the blast wind pressure accelerating the glass fragments into a missile threat only extends to 7 miles
. E.g., many windows were broken in Las Vegas after Nevada tests due to the refraction of blast waves, but the glass fell vertically to the ground without hurting anybody. Note in particular that the blast winds which accelerate the glass from windows blow radially outwards from the bomb, so only windows facing the explosion become a source of fast flying glass fragments. Windows side-on to the blast and on the back of houses can be smashed by the overpressure, but those glass fragments are not accelerated into horizontally flying high-speed missiles. Windows side-on and on the rear of houses are also less likely to break because they are subjected to less than the reflected peak overpressure that the front face of a building receives. For example, rear windows on the houses exposed to the Nevada Apple-2 nuclear test survived where the incident peak overpressure was 1.7 psi, which was enough to break all windows facing the explosion.

Nuclear radiation by itself was an extremely survivable effect, but in combination with thermal flash burns and blast debris injuries, there was a synergism which decreased the LD50 dramatically. Burns wounds which would not be fatal in the absence of simultaneous radiation exposure proved lethal even where the amount of nuclear radiation was not by itself lethal. The mechanism is that the moderate doses of nuclear radiation depressed the white blood cell count for several weeks after exposure, which proved lethal when the patient also had infected burns wounds, because of the absence of enough white blood cells to combat the infection during this crucial time.

A month before nuclear weapons were exploded at Hiroshima and Nagasaki on 6 and 9 of August 1945, weather aircraft were sent over the cities daily to ‘accustom the Japanese to seeing daytime flights of two or three bombers’ (autobiography of 509th bombing group commander and Hiroshima pilot, Colonel Paul Tibbets). B-29 weather aircraft preceded the nuclear B-29 bomber, giving a false sense of security. In Hiroshima the air-raid warning sounded at 7 am, and the all-clear at 7:30 am, but the bomb was dropped at 8:09 am. People cooked breakfasts with charcoal braziers in inflammable wood homes, with paper screens and bamboo furniture. Blasted red-hot charcoal and screens in the wooden houses started fires. In Nagasaki, the air-raid siren sounded at 7:50 am but was cleared before the bomb fell at 11 am.


Above: photo of the tunnel shelters in the hillside near ground zero, Nagasaki. According to both the originally secret U.S. Strategic Bombing Survey 1947 detailed report on Nagasaki and also the openly-published 1956 book The Medical Effects of the Atomic Bomb in Japan, these tunnel shelters had places for 70,000 people but fewer than 400 were in them when the bomb dropped, because the small number of American aircraft passing daily over the cities for weeks beforehand (to build up weather data and target surveillance, as well as to get the anti-aircraft gunnery crews complacent so that the nuclear bomb aircraft would not be shot down before dropping the bomb) without attacking the cities, had gradually worn down the civil defence response to small groups of aircraft passing overhead. People in the shelters survived all the effects intact, as they provided adequate shielding. If the people had taken used the shelters, they would have survived. This photo is Figure 12.52a on page 389 of Glasstone's The Effects of Atomic Weapons, U.S. Department of Defense, 1950.

The originally ‘secret’ May 1947 U.S. Strategic Bombing Survey report on Nagasaki states (Nagasaki, vol. 1, p. 10): ‘... the raid alarm was not given ... until 7 minutes after the atomic bomb had exploded ... less than 400 persons were in the tunnel shelters which had capacities totalling approximately 70,000.’ (National Archives document AIR 48/163). This situation, of most people watching lone B-29 bombers, led to the severe burns by radiation and flying debris injuries in Hiroshima and Nagasaki.

Dr Ashley Oughterson and Dr Shields Warren noted a fire risk in Medical Effects of the Atomic Bomb in Japan (McGraw-Hill, New York, 1956, p. 17):

‘Conditions in Hiroshima were ideal for a conflagration. Thousands of wooden dwellings and shops were crowded together along narrow streets and were filled with combustible material.’

The British Mission to Japan also analysed the damage and casualties in 1945, and comprised of 10 Home Office scientists who had been studying effects of conventional bombing on Britain, and 6 military scientists. Some of these Home Office scientists, particularly Frank H. Pavry (principal scientific officer for civil defence at the Home Office from 1948–76), continued to work on nuclear weapons effects at the Home Office throughout the 1950s, and accompanied by George R. Stanbury (who set up Home Office experiments at the first British nuclear test, Hurricane, 1952) and others, worked out civil defence countermeasures.


Above: photos of crude earth covered wood-frame shelters that survived at 90 metres from ground zero in Nagasaki and 274 metres from ground zero in Hiroshima, amidst the debris from blast and fire effects on the surrounding wooden houses. These photos were first published as photographs 17 and 18 in the 1946 H.M. Stationery Office publication of the report of the British Mission to Japan, The Effects of the Atomic Bombs at Hiroshima and Nagasaki. They then appeared in the June 1950 published British Home Office Civil Defence Manual, Atomic Warfare. They next appeared in a 1963 article by F. X. Lynch entitld 'Adequate Shelters and Quick Reactions to Warning: A key to Civil Defense', published in Science, vol. 142, pp. 665-7, and finally in Cresson H. Kearny's 1979 Oak Ridge National Laboratory publication, Nuclear War Survival Skills. The Japanese wooden frames (they were very short of steel, due to the war effort using up steel to produce aircraft, ships, etc.) were far less protective than the corrugated steel arches of British Anderson shelters, which survived even better when exposed to measured air blast at the Operation HURRICANE nuclear bomb test in 1952. But the basic principle of earth arching worked even with the wooden frame of the Hiroshima shelter, as Kearny's 1979 book explained : 'It's narrow room and a 3-foot-thick earth cover brought about effective earth arching; this kept its yielding wooden frame from being broken.' Earth arching makes the force from the applied air blast loading conduct through the compressed soil, diffracting around the wood or steel frame instead of being passed on to the frame. This arch arching mechanism was a late discovery in the nuclear testing programme, but it was extensively investigated in nuclear tests from 1957 onwards.

The 1946 British Mission to Japan report on Hiroshima and Nagasaki debunks myths about people being vaporised where shadows were cast on flash-burned material: ‘There were cases where a clump of grass or the leaf of a tree has cast a sharp shadow on otherwise scorched wood. Therefore the most intense flash from the ball of fire had ended in a time less than that required to shrivel vegetation.’ It also notes that: ‘even the thin clothing protected from flash burn.’

Equally important, it debunks some of the horror rumours which were spread: ‘a rumour was current which age has made almost respectable, for it appeared in the London Blitz and before that in Barcelona during the Spanish Civil War. This was that large numbers of people had been ripped open by the blast, and their entrails exposed; their eyes and tongues were said also to have hung out. Experience in this country [Britain] has shown that blast pressure alone does not in fact cause these sensational effects ... two Nagasaki survivors who had spoken of seeing hundreds or thousands of such bodies on examination reduced their claim to one or two. Flying debris would be expected to produce a few such injuries.’ (Report of the British Mission to Japan, The Effects of the Atomic Bombs at Hiroshima and Nagasaki, H.M. Stationery Office, London, 1946, pp. 17-18.)

According to the 1979 U.S. Office of Technology Assessment report The Effects of Nuclear War, p. 31: ‘... on a winter night less than 1 percent of the population might be exposed to direct thermal radiation, while on a clear summer weekend afternoon more than 25 percent might be exposed (that is, have no structure between the fireball and the person).’

The secret 1981 U.S. Department of Defence Capabilities of Nuclear Weapons (c. 10, p. 10) states that pain produced by intense thermal radiation provides ‘a useful tool in warning an individual to evade the thermal pulse.’

R. A. Langevin and others in 1958 compared the ability of trained troops and the untrained civilian population to duck and turn away, covering exposed skin (Operations Research, vol. 6, p. 710). Trained troops duck and cover in 0.75 second when a very bright flash occurs. The untrained civilians fared less well: 2% protected themselves within 1 second, 15% by 2 seconds, 50% by 3 seconds, 70% by 4 seconds, 80% by 5 seconds, 90% by 7 seconds, but 7.5% are still fully exposed at 10 seconds after detonation. The young and the old react most slowly if they lack clear simple knowledge of the dangers. Langevin shows that even this untrained protective reaction increases the amount of energy required to cause burns to an exposed population, especially in the case of high-yield weapons which expose the most people.

Dr Samuel Glasstone and Philip J. Dolan stated in the 1977 edition of The Effects of Nuclear Weapons (U.S. Department of Defence, p. 561):

‘Persons exposed to nuclear explosions of low or intermediate yield may sustain very severe burns... These burns may cause severe superficial damage similar to a third-degree burn, but the deeper layers of the skin may be uninjured. Such burns would heal rapidly, like mild second-degree burns.’

At Hiroshima and Nagasaki, high mortality from superficial burns occurred despite the slight depth of charred skin, because of synergistic interaction between nuclear and thermal radiation exposure. This was discovered by Dr James W. Brooks et al. in 1952, and published in their paper ‘The Influence of External Body Radiation on Mortality from Thermal Burns’ (Annals of Surgery, vol. 136, p. 533). Although superficial third-degree burns from the brief thermal pulse of a nuclear explosion are easily survived, a concurrent nuclear radiation exposure of 100 r interferes with recovery by suppressing the white blood cell count, allowing otherwise minor infections to become lethal.

Contrary to antinuclear propaganda claims that people were ‘vaporised’ in Japanese photographs of human ‘shadows’ left behind on otherwise melted asphalt paint and road surfaces, the fact that these shadows exist proves that people blocked the thermal radiation without disappearing. The peak skin temperature is reached when the rate of absorption of energy equals the rate of dissipation of energy by re-emission, blood circulation, and air-cooling. The human body (mainly water) could not be vaporised by the thermal exposures present at ground zero, even if the energy could have somehow diffused throughout a person within the time available. Skin has a thermal conductance of 8 kg.cal/m2/hour/C. Another recurring myth are spectacular keloids (overgrowths of scar tissue) misrepresented as ‘nuclear bomb’ burns: ‘The degree of the keloid formation was undoubtedly influenced by secondary infections, that complicated healing of the burns, and by malnutrition, but more important is the known tendency for keloid formation to occur among the Japanese, as a racial characteristic. Thus, many spectacular keloids were formed after the healing of burns produced in the fire raids on Tokyo.’ (Dr Samuel Glasstone, editor, The Effects of Atomic Weapons, U.S. Department of Defence, September 1950, p. 337.)

In a controlled sample of 36,500 survivors, 89 people got leukemia over a 40 year period, above the number in the unexposed control group. (Data: Radiation Research, volume 146, 1996, pages 1-27.) Over 40 years, in 36,500 survivors monitored, there were 176 leukemia deaths which is 89 more than the control (unexposed) group got naturally. There were 4,687 other cancer deaths, but that was merely 339 above the number in the control (unexposed) group, so this is statistically a much smaller rise than the leukemia result. Natural leukemia rates, which are very low in any case, were increased by 51% in the irradiated survivors, but other cancers were merely increased by just 7%. Adding all the cancers together, the total was 4,863 cancers (virtually all natural cancer, nothing whatsoever to do with radiation), which is just 428 more than the unexposed control group. Hence, the total increase over the natural cancer rate due to bomb exposure was only 9%, spread over a period of 40 years. There was no increase whatsoever in genetic malformations.

Contrast these hard facts to the propaganda first spread by Dr Harold Jacobson, a nuclear effects ignorant Manhattan Project physicist at Los Alamos, who claimed to the International News Service that Hiroshima will be uninhabitable for 75 years, and then falsely added: ‘Any Japanese who try to ascertain the extent of the damage caused by the atomic bomb are committing suicide.’

Examine the post-attack recovery rate in Hiroshima before any significant outside help arrived:


7 August (Day 2): Survivors open bridges and roads to pedestrian traffic, clearing away debris: “The [Hiroshima] prefectural governor issued a proclamation on 7 August, calling for ‘a rehabilitation of the stricken city and an aroused fighting spirit ...’. To prevent the spread of rumors and brace morale, 210,000 out-of-town newspapers were brought in daily to replace the destroyed local paper.” (Source: U. S. Strategic Bombing Survey, The Effects of the Atomic Bombs on Hiroshima and Nagasaki, 19 June 1946, page 9.)

8 August (Day 3): Rail tracks cleared and trains to Hiroshima resumed.

9 August (Day 4): Street trolley bus (electric tram) lines return to service.

1 November (Day 86): “the population of Hiroshima is back to 137,000. ... The official Japanese figures summed up the building destruction at 62,000 out of a total of 90,000 buildings in the urban area, or 69%. An additional 6,000 or 6.6% were severely damaged, and most of the others showed glass breakage or disturbance of roof tile. These figures show the magnitude of the problem facing the survivors. ... In view of the lack of medical facilities, supplies and personnel, and the disruption of the sanitary system, the escape from epidemics may seem surprising. The experience of other bombed cities in Germany and Japan shows that this is not an isolated case. A possible explanation may lie in the disinfecting action of the extensive fires. In later weeks, disease rates rose, but not sharply.” (Source: U. S. Strategic Bombing Survey, The Effects of the Atomic Bombs on Hiroshima and Nagasaki, 19 June 1946, page 9.)


Next, consider what civil defence did during the post-attack recovery process to help aid survivors in Nagasaki, subjected to a nuclear explosion just 3 days after Hiroshima:

9 August (Day 1): Emergency rations are brought in to feed 25,000 survivors (though less than the required amount, due to bureaucratic confusion). The survivors lived in the air-raid shelters, which had survived.

10 August (Day 2): Emergency rations are brought in to feed 67,000 survivors: “this represents a remarkable feat of organisation that illustrates the great possibilities of mass feeding.” (Source: Fred C. Ikle, The Social Impact of Bomb Destruction, University of Oklahoma Press, 1958, p. 147.) “On the morning of 10 August [in Nagasaki], police rescue units and workers from the Kawami-nami shipbuilding works began the imperative task of clearing the Omura-Nagasaki pike, which was impassable for 8,000 feet. A path 6 ½ feet wide was cleared despite the intense heat from smouldering fires, and by August 15 had been widened to permit two-way traffic. No trucks, only rakes and shovels, were available for clearing the streets, which were filled with tile, bricks, stone, corrugated iron, machinery, plaster, and stucco. Street areas affected by blast and not by fire were littered with wood. Throughout the devastated area, all wounded had to be carried by stretcher, since no motor vehicles were able to proceed through the cluttered streets for several days. The plan for debris removal required clearance of a few streets leading to the main highway; but there were frequent delays caused by the heat of smouldering fires and by calls for relief work. The debris was simply raked and shoveled off the streets. By 20 August the job was considered complete. The streets were not materially damaged by the bomb nor were the surface or the abutments of the concrete bridges, but many of the wooden bridges were totally or partially destroyed by fire. ... Despite the absence of sanitary measures, no epidemics broke out here. The dysentery rate rose from 25/100,000 to 125/100,000. A census taken on 1 November 1945 found a population of 142,700 in the city [Nagasaki]. ... Of the 52,000 residential units in the city [of Nagasaki] on 1 August, 14,146 or 27.2 percent were completely destroyed (by Japanese count) (11,494 of these were burned); 5,441 or 10.5 percent were half-burned or destroyed; many of the remaining units suffered superficial or minor damage.” (Source: U. S. Strategic Bombing Survey, The Effects of the Atomic Bombs on Hiroshima and Nagasaki, 19 June 1946, pages 12-13.)

7 October (Day 60): The first green shoots of recovery appeared on an irradiated and firestorm-burned chestnut tree, photographed by U.S. Air Force observers, and published in the U.S. Congress book, The Effects of Nuclear War, 1979:


Above: the U.S. Office of Technology Assessment published a very poorly researched book in May 1979 (full of popular lies about ozone layer damage, and so on) called The Effects of Nuclear War in which the one useful disclosure (on page 114) was this U.S. Air Force photo of the leaves and new shoots appearing on a chestnut tree in Nagasaki 2 months after being irradiated with gamma rays and neutrons and then charred and burned in the fires which followed. Predictably, this one piece of honesty is omitted from the online PDF version of that book by the Federation of American Scientists here (which is so poorly scanned for page 114 that not even a single word of the photo caption is readable), and also hosted by Princeton University here. Robert Jungk, Children of the Ashes (Heinemann, London, 1961): 'one morning in April 1946, the Vice-Mayor [of Hiroshima] gazed for a long time. For what met his eyes was a sight he had scarcely hoped ever to see again ... The blackness of the branches was dappled with the brilliant white of cherry buds opening into blossom.'

Robert Jungk carefully investigated the history of the recovery in Hiroshima by interviewing the people involved and collecting first hand reports, and gives further interesting details in his book Children of the Ashes (Heinemann, London, 1961):

1. On 31 August 1945: 'the first locally produced and locally printed post-war edition of the Chugoku Shimbun was on sale in the streets of Hiroshima ... 'Our darkroom was an air-raid shelter dug into the hillside [which survived of course]', one of the editors remembers, 'but our type had to be cast in the open air, under the sunny sky.'

2. On 7 September 1945, the Chugoku Shimbun reported that Hiroshima then had a population estimated to be 130,000.

3. On 10 September 1945, electricity was reconnected to some parts of Hiroshima: 'huts made of planks quickly knocked together ... already had electric light.'

4. On 5 November 1945, the Chugoku Shimbun reported that - despite inertia and delays due to 'the rigidity of bureaucratic procedure' which was hindering the recovery rate - a lot of progress was being made:

'Housing. The building of houses is to be systematically begun on 15 November. ...

'Tramways. At present, ten trams are in commission on the main route, eight on the Miyajima route and five muncipal buses. These twenty-three vehicles must cater for an average of 42,000 persons daily.'

Some 70% of the destroyed buildings of Hiroshima had been reconstructed by mid-1949. (Ref.: Research Department, Hiroshima Municipal Office, as cited in Hiroshima, Hiroshima Publishing, 1949. Other recovery data are given in U.S. Strategic Bombing Survey, The Effects of Atomic Bombs on Hiroshima and Nagasaki, Washington, D.C., 1946, p. 8.)


Above: the Chugoku newspaper building 870 m east of GZ Hiroshima, gutted by fire. Unlike the CND 'survivors would envy the dead' propaganda of big name 'journalists' (anti-civil defense propagandarists) of today, those journalists at Hiroshima didn't let a nuclear attack deflect them from their duty of reporting news truthfully. They go on with the task of helping to keep morale up, and assisting the flow of information needed to rebuild Hiroshima. They rolled their sleeves up, and got to work, setting type outdoors, processing photographic prints in an old air raid shelter! These journalists are a model for civil defense!



'I must confess that as an expert, my original view, and the view I held during the time I was on the SALT delegation, was that there was no defense against nuclear war and that there was no realistic recovery from it. ... [However, upon checking the actual facts... ] The day after the blast, bridges in downtown Hiroshima were open to traffic. Two days later, the trains started to run again, and three days later, some of the streetcar lines were back in operation.'

- Thomas K. Jones, Program and Product Evaluation Manager, Boeing Aerospace Company, Testimony the Hearings before the Joint Committee on Defense Production, U.S. Congress, 17 November 1976.


Nuclear winter and related lies debunked by actual firestorm data

Of thousands of nuclear test explosions, the one “nuclear winter” from the Hiroshima fire storm blocked out the sun for 25 minutes (from burst time at 8:15 am until 8:40) in Hiroshima as shown by the meteorological sunshine records printed in Figure 6 (3H) of Drs. Ashley W. Oughterson, Henry L. Barnett, George V. LeRoy, Jack D. Rosenbaum, Averill A. Liebow, B. Aubrey Schneider, and E. Cuyler Hammond, Medical Effects of Atomic Bombs: The Report of the Joint Commission for the Investigation of the Effects of the Atomic Bomb in Japan, Volume 1, Office of the Air Surgeon, report NP-3036, April 19, 1951, U.S. Atomic Energy Commission. Nobody is recorded as being a casualty from the 25 minutes of sunlight deprivation!

The reason? The soot is hydroscopic. It absorbs water and falls out in black rain. The firestorm took 30 minutes to start and was at peak intensity 2-3 hours later, so radioactive mushroom cloud been blown many miles downwind before the black rain occurred over Hiroshima, contrary to ignorant lies about “fallout radiation”. The soot doesn’t freeze the planet. The soot was instead rapidly precipitated in a self-induced rainout as was pointed out back in 1983 by J. B. Knox in Lawrence Livermore National Laboratory report UCRL-89907, which nuclear propaganda ignored. No other nuclear explosion ever created a firestorm. Even those near naturally forested Pacific islands failed to ignite the vegetation by thermal radiation.

Targeting oil wells instead of cities reduces the moisture effect, but the soot doesn't rise high enough from burning oil wells, as proved when Saddam set fire to all of Kuwait’s oil fields. This has all been intensively researched and documented. Regarding the non-soot dust injected into the stratosphere, unlike soot it’s not a strong absorber of sunlight and weather records were intensively studied for signs of both nuclear winter and ozone depletion during hundreds of megatons of atmospheric 1945-62 nuclear tests, with failure.

The initial gamma radiation from a nuclear explosion produces more ozone than it destroys. Gamma radiation produces large amounts of ozone from atmospheric oxygen regardless of the burst altitude, but ozone-destroying nitrogen oxides are only produced by the high-density air blast of low-altitude nuclear explosions. Those nitrogen oxides then combine with water vapour in the turbulent toroidal circulation of the mushroom cloud to form nitric acid, which does not destroy ozone but simply gets deposited, very diluted, in rain. This was proved in the 1970s when aircraft were flown through mushroom clouds from Chinese nuclear tests. In high altitude nuclear explosions, there is no compressed blast wave that forms nitrogen oxides, so you actually get a boost to the ozone layer since the explosion produces vast amounts of ozone due to the gamma radiation.

Even the “nuclear winter” from mass fires, dust, and other effects from the well-established 100 million megatons K-T explosion 65 million years ago failed to wipe out plants and mammals. Instead, it made extinct the dangerous cold-blooded reptiles that were preventing freedom for peaceful mammal evolution. The idea that there is no protection and no possibility of surviving against a big explosion is false. Claiming that nuclear wars cannot be won if you lie and exaggerate the effects of nuclear weapons and the effects of nuclear war while downplaying countermeasures, is exactly what encouraged the terrorists to exploit the most feared weapons in the 1930s while peace-loving nations disarmed and thus effectively signed the death warrant for six million Jews on “peace treaties” with liars.

One of the Scientific American’s Cold War publishers, Gerard Piel, had a long history of lying and publishing lies about fires from nuclear weapons to attack civil defense readiness, just as his predecessors did in Britain during the 1930s (which made the Prime Minister appease Hitler, encouraging him to start WWII). Typical example of lie:

“A heading in one recent report concerned with effects of nuclear detonations reads, ‘Megatons Mean Fire Storms,’ and the report predicts that a 20-megaton nuclear burst is sure to produce a 300-square mile fire storm. [Reference: Gerard Piel (then the anti-civil defense publisher of the Scientific American), ‘The Illusion of Civil Defense,’ published in the Bulletin of the Atomic Scientists, February 1962, pp. 2-8.] The report further states that blastproof bomb shelters afforded no protection in World War II fire storms, and the reader is left to conclude that vast fire storm areas in which there will be no survivors are an assured consequence of future nuclear attacks. ... the 40,000-50,000 persons killed by the fire storm at Hamburg constituted only 14 to 18 percent of the people in the fire storm area and 3 to 4 percent of Hamburg’s total population at the time of the attack. ... Two of three buildings in a 4.5 square mile area were burning 20 minutes after the incendiary attack began at Hamburg, and similar figures were reported for other German fire storm cities.”

- Robert M. Rodden, Floyd I. John, and Richard Laurino, Exploratory Analysis of Fire Storms, Stanford Research Institute, AD616638, 1965, pages 1, 5.

Media lying about the thermal ignitions (leading to lies about firestorms and nuclear winter caused by the soot of such fires blocking sunlight) can be traced back to the secret classification of the full three-volume 1947 report on Hiroshima by the Strategic Bombing Survey, which was edited out of the brief single volume “summary” that the openly published a year earlier, 1946. Here is the key revelation (originally ‘secret’ May 1947 U.S. Strategic Bombing Survey report on Hiroshima, pp. 4-6):

‘Six persons who had been in reinforced-concrete buildings within 3,200 feet [975 m] of air zero stated that black cotton black-out curtains were ignited by flash heat… A large proportion of over 1,000 persons questioned was, however, in agreement that a great majority of the original fires were started by debris falling on kitchen charcoal fires ... There had been practically no rain in the city for about 3 weeks. The velocity of the wind ... was not more than 5 miles [8 km] per hour.... Hundreds of fires were reported to have started in the centre of the city within 10 minutes after the explosion... almost no effort was made to fight this conflagration ... There were no automatic sprinkler systems in building...’ [Emphasis added.]


No modern city today is built out of 1945 Hiroshima style wood frame houses with charcoal stoves amid bamboo furnishings and paper screens. Even Hiroshima is no longer built like that, it’s a modern steel, concrete, and brick city and would not suffer a firestorm if a bomb dropped on it again.

Even where city firestorms have actually occurred in obsolete wooden city areas of Japan and Europe, there was not a nuclear winter. What about the theoretical predictions that a nuclear attack on oil supplies will cause a nuclear winter, made by the founder of nuclear winter hype, Paul Crutzen? Saddam Hussein’s Iraqi army invaded Kuwait and set all of its oil wells on fire as it was driven back into Iraq by America in 1991.

Peter Aldhous, ‘Oil-well climate catastrophe?’, Nature, vol. 349 (1991), p. 96:

“The fears expressed last week centred around the cloud of soot that would result if Kuwait’s oil wells were set alight by Iraqi forces ... with effects similar to those of the ‘nuclear winter’ ... Paul Crutzen, from the Max Planck Institute for Chemistry in Mainz, has produced some rough calculations which predict a cloud of soot covering half of the Northern Hemisphere within 100 days. Crutzen ... estimates that temperatures beneath such a cloud could be reduced by 5-10 degrees C ...”

Dr Richard D. Small of Pacific-Sierra Research Corporation, California, responded in Nature, vol. 350 (1991), pp. 11-12, that 16,000 metric tons of actual soot is produced from 220,000 metric tons of oil burned every day, and anyway:

“My estimates of the smoke produced by destruction of Kuwait’s oil wells and refineries and the smoke stabilization altitude do not support any of the purported impacts. The smoke is not injected high enough to spread over large areas of the Northern Hemisphere, nor is enough produced to cause a measurable temperature change or failure of the monsoons.”

It turned out that the nuclear winter hype was false, because even if you do somehow manage to start a firestorm in the modern world (the overcrowded fire-hazard wooden medieval areas of Hamburg, Dresden, and Hiroshima weren’t rebuilt with wood after they burned in firestorms), it simply doesn’t produce a stable layer of soot in the stratosphere like the computer simulation. At Hiroshima the soot returned to the ground promptly because it is hydroscopic: it forms water droplets, rain. (It wasn’t fallout: the firestorm took over 20 minutes to get doing, by which time the radioactive mushroom cloud had been blown miles downwind.)

8 Comments:

At 10:10 am, Blogger nige said...

Nuclear winter has quite an interesting history. It started off with the comet impact that wiped out the dinosaurs. The comet forms a fireball when it collides with the atmosphere, and the thermal radiation is supposed to ignite enough tropical vegetation to produce a thick smoke cloud, freezing the ground and killing off many species.

The best soot to absorb solar radiation is that from burning oil, and Saddam tested this by igniting all of Kuwait's oil wells after the first Gulf War. Massive clouds of soot were produced, but the temperature drop was far less than "nuclear winter" calculations predicted occurred in the affected areas: http://en.wikipedia.org/wiki/Nuclear_winter#Kuwait_wells_in_the_first_Gulf_War

The idea that a dark smoke layer will stop heat energy reaching the ground is naive because by conservation of energy, the dark smoke must heat up when it absorbs sunlight, and since it is dark in colour it is as good at radiating heat as absorbing it. So it passes the heat energy downwards as the whole cloud heats up, and when the bottom of the cloud has reached a temperature equilibrium with the top, it radiates heat down to the ground, preventing the dramatic sustained cooling.

Although there is a small drop in temperature at first, as when clouds obscure the sun, all the soot cloud will do in the long run is to reduce the daily temperature variation of the air from day to night, so that the temperature all day and all night will be fairly steady and close to the average of the normal daytime and nighttime temperatures.

The dinosaur extinction evidence, http://en.wikipedia.org/wiki/Chicxulub_Crater, might be better explained by the direct effects of the comet impact: the air blast wave and thermal radiation effects on dinosaurs, and the kilometers-high tsunami. At the time the comet struck Chicxulub in Mexico with 100 TT (100,000,000 megatons or 100 million million tons) energy 65 million years ago, the continents were all located in the same area, see the map at http://www.dinotreker.com/cretaceousearth.html and would all have suffered severe damage from the size of the explosion. Most dinosaur fossils found are relatively close to the impact site on the world map 65 million years ago.

Another issue is that some proportion of the rock in the crater was calcium carbonate, which releases CO2 when heated in a fireball. If there was enough of it, the climatic effects would have been due to excessive heating, not cooling.

The "nuclear winter" idea relies on soot, not dust such as fallout (which is only about 1% of the crater mass, the remainder being fallback of rock and crater ejecta which lands within a few minutes). So it is basically an extension of the massive firestorms theory, which has many issues because modern cities don't contain enough flammable material per square kilometre to start a firestorm even when using thousands of incendiaries. In cases such as Hiroshima, the heavy fuel loading of the target area created a smoke cloud which carried up a lot of moisture that condensed in the cool air at high altitudes, bringing the soot back promptly to earth as a black rain.

Because this kind of thing is completely ignored by "nuclear winter" calculations, the whole "nuclear winter" physics looks artificial to me. In 1990, after several studies showed that TTAPS (Sagan et al.) had exaggerated the problem massively by their assumptions of a 1-dimensional model and so on, TTAPS wrote another paper in Science, where they sneakily modified the baseline nuclear targetting assumptions so that virtually all the targets were oil refineries. This enabled them to claim that a moderate cooling was still credible. However, the Kuwait burning oil wells experience a few years later did nothing to substantiate their ideas. Sagan did eventually concede there were faulty assumptions in the "nuclear winter" model, although some of his collaborators continue to write about it.

 
At 2:12 pm, Anonymous Anonymous said...

For Chicxulub impactor 100TT value is very consevative,real value ~700TT,and recent research indicated that this impact not kill dinosaurs.Killer was asteroid that produced the Shiva crater 40-45km in diameter .

 
At 2:20 pm, Anonymous Anonymous said...

Shiva impact conservative estimation-3.46*10^9 megatons.

 
At 1:02 pm, Anonymous Anonymous said...

What about effects of very very high-yield very high altitude detonations?
Consider a 30 gigaton nuclear explosion at 400km altitude what would be effects?

 
At 1:18 pm, Blogger nige said...

Hi Anonymous,

There is extensive data on this from computer fireball simulations of comet impacts, which has been checked against the effects of immense explosions resulting from the July 1994 impacts on Jupiter which were filmed and photographed by the Hubble space telescope and many earth-based telescopes.

Above 1 Gigaton yield (which I must stress is such a big heavy warhead that it cannot conceivably be a terrorist or enemy threat in the foreseeable future), the thermal and fire effects on forests are generally severe, because the duration of the thermal pulse tail end lasts a long time, and thus it can dry out the vegetation (turning it into tinder or kindling) and then ignite it before the thermal pulse has ended.

Obviously for a burst at 400 km altitude, you need a very high yield to make the "X-ray pancake" fireball radiate enough energy to the ground to start fires.

There is a discussion of the X-ray re-radiation (transfer) calculations in the thermal radiation effects chapter of Glasstone and Dolan, The Effects of Nuclear Weapons, 3rd ed., 1977 and in Brode's 1968 paper in the Annual Review of Nuclear Science vo. 18, pp. 153-202, and also in Bridgman's 2001 DTRA book Introduction to the Physics of Nuclear Weapons Effects, but they don't go up to 1 Gt yield. You would need to do calculations, preferably using the Los Alamos fireball computer simulation software they verified against the 1994 Jupiter impacts fireball luminosity, to get exact answers.

A very crude calculation is to scale up data from the 9 July 1962 Starfish Prime 1.4 Mt nuclear test at 400 km to the yield of 1 Gt. This may not be accurate, because the X-ray pancake properties will not scale up linearly but will qualitatively change as the energy deposition increases.

E.g., for very high yields at 400 km, the top of the atmosphere (below the fireball) will get very hot and may tend to rise ballistically, instead of staying in the same place (as occurs with lower yields detonated at the same altitude). So you need to take that extra physical dynamic into account to reliably predict the thermal exposure on the ground. If the hot X-ray pancake fireball rises fast for big bomb yields, then it reduces the predicted thermal exposure of the ground due to the inverse-square law between the source of the thermal radiation (the height of the X-ray pancake fireball) and the target.

 
At 10:22 pm, Anonymous Anonymous said...

How could he said that a human body would not vaporize at the ground zero of an atomic explosion? Can anyone give a more detailed answer regarding this? So if even a nuclear explosion can't vaporize a human being, so what kind of explosion that can vaporize humans instantly? I think he's gonna say that human body will never be vaporize at any ground zero of a nuclear explosion. He is nonsense.

 
At 12:16 am, Blogger nige said...

Hiroshima's ground zero was 600 metres under explosion because it was an AIR BURST at 600 metres height, not a surface burst.

People in the open at ground zero received surface burns on the side facing ground zero: the thermal exposure at ground zero (600 metres) from a 16 kt Hiroshima detonation with 1/3rd thermal radiation yield (ignoring atmospheric attenuation) by the inverse square law is equal to {16 (1/3) x 10^12 calories}/(4*Pi*600^2) = 1.28 x 10^6 calories/m^2 or 118 cal/cm^2.

Now, 1 cal is the temperature needed to raise the temperature of 1 gram (1 cm^3) of water (humans are 70% water) by 1 degree centigrade or 1 K, from 15 to 16 C. For humans, to reach vaporization you need to go from 37 to 100 C. If 118 cal/cm^2 is distributed in the top 1 cm thickness of flesh (with no loss due to heat reflection, ablation of the top 1 mm layer, and other damage-limiting processes) then that top 1 cm layer could potentially gain about 118 C in temperature, reaching 155 C (37 C body temperature + 118 C = 115 C), IGNORING the change of state from water to steam when 100 C is passed.

However, you need a massive amount of energy (enthalpy of vaporization, see http://en.wikipedia.org/wiki/Enthalpy_of_vaporization ) to drive water from 99 C to 100 C, because water molecules have strong bonds between them which need to be broken when water turns to steam.

"... the molecules in liquid water are held together by relatively strong hydrogen bonds, and its enthalpy of vaporization, 40.65 kJ/mol [note that 1 cal = 4.186 J, while 1 mole consists of 6.022 x 10^23 molecules of water per 18 grams of water], is more than five times the energy required to heat the same quantity of water from 0 °C to 100 °C."

- http://en.wikipedia.org/wiki/Enthalpy_of_vaporization

So the Hiroshima bomb did NOT deliver enough heat flash energy at GROUND ZERO to even vaporize a layer of water 1 cm thick. If you look at the data on the scorching depths of wood by the thermal flash at the 1955 Operation Teapot tests (Kyle P. Laughlin, Thermal Ignition and Response of Materials, Report to the Test Director, Operation TEAPOT, Nevada Test Site, February-May 1955, Office of Civil and Defense Mobilization, weapon test report WT-1198, December 1957, AD0611227), less than 1 mm of the surface of the wood was removed even by 50 cal/cm^2 or more: additional energy did not increase the depth of charring (the extra energy just went into ablating the top 1 mm more forcefully into a smoke cloud, which then absorbed the remainder of the heat flash and kept the heat absorbed well away from the underlying wood). The same applies at Hiroshima, where the moisture content of skin was 70% (much higher than wood, which was easier to heat, due to less water content; WATER HAS THE HIGHEST SPECIFIC HEAT CAPACITY OF ANY COMMON MATERIAL ON THE PLANET).

The only reason that the top 0.1 mm of roof tile surfaces bubbled at ground zero in Hiroshima was the failure of the 118 cal/cm^2 to penetrate more deeply than 0.1 mm. The tiny depth of the surface which absorbed the energy ensured that the temperature rise was massive, over 2000 C in that tiny 0.1 mm tile surface. Nobody was instantly killed by thermal radiation outside; the nuclear radiation was lethal.

 
At 12:17 am, Blogger nige said...

The "nonsense" comes from the liars who sell lies to the public to make them give up on civil defence so they can concentrate solely on provable failures like lying for disarmament and claiming this will solve human problems; despite the fact that it actually ENCOURAGED thugs to exploit the lies in the 1930s.

LYING SOLVES NOTHING. Democracy requires FACTS. The moment we give up searching for facts and surrender to fashionable delusion, we will be like Russia 1917, Germany 1933, or Japan 1941. MAD. We need to permit critical scientific appraisal of FACTS, not suppress them. People need to know what they the effects of nuclear weapons really are, not lies for political "solutions" which so far have never prevented wars from occurring, and have often encouraged aggression by leading to appeasement through helpless vulnerability to terrorism and coercion.

 

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