The effects of nuclear weapons. Credible nuclear deterrence, debunking "disarm or be annihilated". Realistic effects and credible nuclear weapon capabilities for deterring or stopping aggressive invasions and attacks which could escalate into major conventional or nuclear wars.

Monday, June 12, 2006

Samuel Cohen's Neutron Bomb: Debunking Communist Cold War Propaganda

Seen in 1999, Sam Cohen holds up a peace medal given to him by Pope John Paul I. He designed the neutron bomb with just pencil, paper and a slide rule. (San Jose Mercury News)

Above: the target for Sam Cohen's neutron bomb was these T-54/55 Russian main battle tanks, which had the highest production run of any tank ever made (over 86,000 were manufactured). They were manufactured chiefly for the invasion of Western Europe, once tactical nuclear weapons had been removed by political lobbying of Western disarmament activists via the Kremlin-controlled World Peace Council based in Moscow.

“The first objection to battlefield ER weapons is that they potentially lower the nuclear threshold because of their tactical utility. In the kind of potential strategic use suggested where these warheads would be held back as an ultimate countervalue weapon only to be employed when exchange had degenerated to the general level, this argument loses its force: the threshold would long since have been crossed before use of ER weapons is even contemplated. In the strategic context, it is rather possible to argue that such weapons raise the threshold by reinforcing the awful human consequences of nuclear exchange: the hostages recognize they are still (or once again) prisoners and, thus, certain victims.”

- Dr Donald M. Snow (Associate Professor of Political Science and Director of International Studies, University of Alabama), “Strategic Implications of Enhanced Radiation Weapons”, Air University Review, July-August 1979 issue (online version linked here).

'The neutron bomb, so-called because of the deliberate effort to maximize the effectiveness of the neutrons, would necessarily be limited to rather small yields - yields at which the neutron absorption in air does not reduce the doses to a point at which blast and thermal effects are dominant. The use of small yields against large-area targets again runs into the delivery problems faced by chemical agents and explosives, and larger yields in fewer packages pose a less stringent problem for delivery systems in most applications. In the unlikely event that an enemy desired to minimize blast and thermal damage and to create little fallout but still kill the populace, it would be necessary to use large numbers of carefully placed neutron-producing weapons burst high enough to avoid blast damage on the ground [500 metres altitude for a neutron bomb of 1 kt total yield], but low enough to get the neutrons down. In this case, however, adequate radiation shielding for the people would leave the city unscathed and demonstrate the attack to be futile.'

- Dr Harold L. Brode, RAND Corporation, Blast and Other Threats, pp. 5-6 in Proceedings of the Symposium on Protective Structures for Civilian Populations, U.S. National Academy of Sciences, National Research Council, Symposium held at Washington, D.C., April 19-23, 1965.

“You published an article ‘Armour defuses the neutron bomb’ by John Harris and Andre Gsponer (13 March, p 44). To support their contention that the neutron bomb is of no military value against tanks, the authors make a number of statements about the effects of nuclear weapons. Most of these statements are false ... Do the authors not realise that at 280 metres the thermal fluence is about 20 calories per square centimetre – a level which would leave a good proportion of infantrymen, dressed for NBC conditions, fit to fight on? ... Perhaps they are unaware of the fact that a tank exposed to a nuclear burst with 30 times the blast output of their weapon, and at a range about 30 per cent greater than their 280 metres, was only moderately damaged, and was usable straight afterwards. ... we find that Harris and Gsponer’s conclusion that the ‘special effectiveness of the neutron bomb against tanks is illusory’ does not even stand up to this rather cursory scrutiny. They appear to be ignorant of the nature and effects of the blast and heat outputs of nuclear weapons, and unaware of the constraints under which the tank designer must operate.”

- C. S. Grace, Royal Military College of Science, Shrivenham, Wiltshire, New Scientist, 12 June 1986, p. 62.

Above: Lying CND propaganda postcard on the neutron bomb issued by Yorkshire Region CND (campaign for nuclear disarmament). The back of the postcard falsely claims: 'Civilians, rather than easily protected tanks, will be the main targets.' You can't easily protect a tank from hundreds of thousands of rads of extremely high energy (14.1 MeV) fusion neutrons, which is the whole point of the neutron bomb. The well-known good absorbers for low energy neutrons in a nuclear reactor (cadmium and boron) are relatively ineffective at capturing such high energy neutrons, and if you use heavy metals to scatter and slow down the high energy neutrons, like steel or depleted uranium, you get gamma rays given off when the neutrons deposit energy in the nuclei they strike. So then you have a secondary radiation hazard, not to mention the immense weight increase to the tank which would have major implications (tanks are normally extremely heavy and a massive increase in armour would have severely detrimental effects, such as bogging them down more easily, increasing fuel consumption and decreasing speed). If civilians (not in tanks) were the targets, you wouldn't need to use short-range radiation effects because you could just use blast and fallout against them, but they weren't the targets. As the lying CND propagandarists knew, the deterrent targets were the Warsaw Pact communist tanks which outnumbered those on the West by three-to-one:

Joseph C. Harsch, 'Neutron Bomb: Why It Worries The Russians', Christian Science Monitor, August 14, 1981, p. 1: "[there] are 19,500 tanks in the Soviet-controlled forces of the Warsaw Pact aimed at Western Europe. Of these, 12,500 are Soviet tanks in Soviet units. NATO has 7,000 tanks on its side facing the 19,500."

Above: Samuel Cohen's calculation of the gamma dose rate from deposited fallout formed Appendix D of Glasstone's 1950 Effects of Atomic Weapons. Cohen also contributed the analysis of dose rates to aircraft flying inside the mushroom cloud at various times after detonation. In his fallout calculations (Appendix D), Cohen ignored air scattered gamma ray contributions and just summed the direct gamma ray contributions from a smooth plane. It turned out that this approximation gave results which are accurate for typical rough ground if scattered gamma rays are included. For a smooth, infinite, uniformly contaminated surface including the contribution from air scattered gamma rays, 50% of the dose rate at 1 metre height comes from fallout within a 15 metres radius; for Cohen's approximation (ignoring air scatter) this radius is only 8 metres which is about the same as for rough terrain (where the terrain absorbs some of the radiation, particularly from great distances) where air scatter is included.

While he did not discuss Dr Samuel T. Cohen’s neutron bomb in The Effects of Nuclear Weapons, Glasstone in an article called 'Nuclear Weapons' for Microsoft's Encarta 97 critically argued that 95 % clean neutron bombs are the way forward, to totally avoid collateral damage in nuclear war (published by Microsoft Corporation in the Microsoft Encarta 97 Encyclopaedia CD-ROM, 1997):
‘If an H-bomb were made with no uranium jacket but with a fission trigger ... as little as 5 percent of the total explosive force might result from fission; the weapon would thus be 95 percent clean. The enhanced radiation fusion bomb, also called the neutron bomb, which has been tested by the United States and other nuclear powers ... is considered a tactical weapon because it can do serious damage on the battlefield [assuming a 1-kt air burst at 500 m altitude], penetrating tanks and other armoured vehicles and causing death or serious injury to exposed individuals, without producing the radioactive fallout that endangers people or structures miles away.’

Samuel Glasstone was well aware of the facts on the neutron bomb, for he had taught classified nuclear weapons design at Los Alamos until he retired and moved to Oak Ridge (Glasstone was co-author with Leslie M. Redman of the originally Secret - Restricted Data June 1972 report WASH-1038, An Introduction to Nuclear Weapons):

'When I arrived at the [Los Alamos] Lab 36+ years ago ... though I was a lowly postdoc, we took a course on nuclear physics (as did every new employee) and then a class on elements of bomb design both taught by Samuel Glasstone. This was required training. ... After that approximately 3 weeks of training, I understand what the Lab was about and why it was important to the nation. I'm certain it contributed to my wanting to stay on after my postdoc and has helped me in my work over the years. This was part of the "openness" despite the secrecy associated with the Lab. I believe we have lost this over the years ...' - Dr David Forslund

'During the Manhattan Project, classification was easy: everything in the project was classified. Then and later, information on nuclear weapons was "born classified" in the Restricted Data category. During the [Los Alamos National] Lab's orientation for new hires in the mid-1960s, Sam Glasstone, who had been a chemist in the Manhattan Project, drew one circle on the blackboard and another inside it. "Drawing concentric circles used to be classified," he joked. Fission bombs are designed in concentric circles.' - Dr Cheryl Rofer, Los Alamos National Laboratory, Part I - Historical Perspectives ['Cheryl Rofer is a chemist who worked for the Los Alamos National Laboratory for 35 years. ...'], Word Worth, September 2004, volume IV, No. 9.

Above (click on images to enlarge): the neutron bomb is included under the title 'enhanced neutron weapon' in Philip J. Dolan's originally secret manual Capabilities of Nuclear Weapons, DNA-EM-1, U.S. Department of Defense, Chapter 5, Nuclear Radiation Phenomena, August 1981 revision. According to the Medical NBC Battlebook, USACHPPM Tech Guide 244, May 2000, page 2-18, a 3 kt enhanced neutron weapon with a fission yield of 50% (i.e. 5% of yield as residual radiation, which is a trivial effect for the burst height of the neutron bomb) will release 30% of its energy as blast (trivial for the 720 metres height of burst for tactical use of a 3 kt neutron bomb), 20% as thermal radiation (again, relatively trivial even near ground zero, due to yield and burst altitude), and 45% as inital nuclear radiation. These ratios will be altered for other fission yields. At very low yields, there is a problem with using a small fission primary to ignite the fusion stage in a Teller-Ulam device because the fraction of yield released as X-rays by a very low yield fission device is small (it depends strongly on the yield to mass ratio of the primary stage), thus the fusion stage ignition-efficiency due to X-ray ablation induced recoil falls. Most of the energy from a low yield primary stage is in a relatively slow moving (compared to light-velocity X-rays) debris hydrodynamic shock wave, that delivers energy to the fusion stage slowly and without efficient focussing. Fortunately, the neutron bomb is not concerned with maximising Teller-Ulam efficiency, but with producing a small yield with a maximised neutron output!

The basic mechanism of the neutron bomb was discovered by Samuel Cohen of RAND Corporation in 1958 when studying the neutron outputs from two Lawrence Livermore National Laboratory clean (low fission) bomb designs (Dove and Starling) of low yield devices for peaceful explosive uses like excavating harbours, canals, and mountain passes, and is simply that the case thickness needed by a Teller-Ulam device to channel X-rays from primary to secondary scaled as the cube root of the total yield. Hence the casing required is 10 times thicker for 1 Mt than for 1 kt, so in a 1 kt Teller-Ulam device, most of the neutrons can escape from the thin casing, while in a 1 Mt Teller-Ulam device the neutrons are mostly absorbed because of the much thicker casing required. Thus neutron bombs have a yield range of 1-10 kilotons, with fission yield varying from 50% at 1-kiloton to 25% at 10-kilotons (all of which comes from the primary stage). The neutron output per kiloton is 10-15 times greater than for a pure fission implosion weapon.Above: neutron attenuation in air according to energy, in Philip J. Dolan's originally secret manual Capabilities of Nuclear Weapons, DNA-EM-1, U.S. Department of Defense, Chapter 5, Nuclear Radiation Phenomena, August 1981 revision (the simple geometric inverse square law of divergence of neutrons from a point source isn't included in the shielding curves above). Notice that over small distances in the air, the neutron fluence is higher than in a vacuum, because there is little attenuation by air over a short distance, but you get an additional large neutron dose from neutrons being scattered back at you which have gone past (and also through) you, and have then been scattered back at you, by large number of nuclei which are obviously located at greater distances (beyond your distance from the detonation!). This is also why tanks can't be protected with a relatively light weight shield on top of the crew compartment, as we shall see later on: it is not possible to protect tanks existing against neutron radiation without adding so much mass the turret would be retarded and the performance of the tank would be crippled. A tank designed to properly protect its crew against 14.1 MeV neutron bomb neutrons and with a big enough engine to perform reasonably well, would be so heavy it would be swallowed up by the earth and simply disappear into soft ground, being rendered useless (the shielding of 14.1 MeV neutrons has nothing to do - either in mechanism or in amount of shielding - with the easy-to-shield thermalized 0.025 eV neutrons by cadmium control rods in a nuclear reactor).
Above: neutron bomb doses compared to other weapons, in Philip J. Dolan's originally secret manual Capabilities of Nuclear Weapons, DNA-EM-1, U.S. Department of Defense, Chapter 5, Nuclear Radiation Phenomena, August 1981 revision.

The enhanced neutron weapon or ‘neutron bomb’ is just a relatively clean very low yield two stage Teller-Ulam device; the low total yield means that only a very thin steel casing is required to reflect X-rays from the fission primary on to the fusion secondary stage. The thin casing of such a weapon ensures that most of the 17.6 MeV fusion energy from deuterium and tritium fusion into helium-4 escapes as neutrons: 80% of the energy is carried by neutrons, and 20% is carried by the helium-4 nucleus or alpha particle. This suppresses the amount of energy available for producing the blast and thermal radiation effects.

The primary strategic uses of clean, low fission yield enhanced neutron warheads are:

(1) to avert EMP collateral damage (due to low fission yield and low total yield) for ABM missiles by using the neutron output to melt and destroy plutonium cores in incoming ICBMs (neutrons have a long range in space);

(2) to deter massed tank attacks in cities or close to friendly forces. The deterrent here is the fact that neutron irradiated tank crews would be disabled within minutes and dead within hours to days; and

(3) to deter warship assaults by the threat of putting them out of action without nearby collateral damage or fallout.

Steel armour is resistant to blast and heat, but provides little shielding against fast fusion neutrons. The well-known neutron absorbers used in nuclear reactor control rods are little use against neutron bomb radiation, because they are good absorbers of 0.025 eV ‘thermalized’ neutrons in a nuclear reactor with a moderator, but useless against the 14.1 MeV neutrons from neutron bomb fusion, which have 560 million times more energy than thermal neutrons. Heavier armor, like that of the M-1 tank, employs depleted uranium which (although it is not significantly fissioned by low-energy thermal neutrons) actually increases the effectiveness of neutron radiation because it undergoes fission when hit by the 14.1 MeV high energy neutrons from neutron bomb, generating additional neutrons and becoming radioactive.

Because the blast and heat are suppressed in the neutron bomb, they have a similar damaging range to the lethal neutron radiation, so there is no collateral damage outside the target area. In some cases, a few broken windows can occur at greater distances, but there is no risk of dangerous blast-wind accelerated glass fragments, because the blast winds are trivial outside the neutron irradiate area.

Provided that the weapon was not used in a thunderstorm, no fallout effects would occur from the use of a neutron bomb, as the combination of 500 m burst altitude and low yield prevents fallout in addition to significant thermal and blast effects. The reduction in damage outside the target area is a major advantage of such a weapon to deter massed tank invasions. An aggressor would thus be forced to disperse tanks, which would make them easier to destroy by simple hand-held anti-tank missile launchers.

In 1979, Samuel Cohen was in Paris helping the French build neutron bombs, when presidential candidate Ronald Reagan came through on a European tour. Cohen met with Reagan to brief him on the neutron bomb. Reagan grasped the idea of neutron weaponry immediately, and made a pledge to Cohen that he would reverse Carter administration policy by building and deploying neutron bombs.

Sam Cohen's book, The Truth About the Neutron Bomb: the Inventor of the Bomb Speaks Out, William Morrow and Co., New York, 1983, on page 48 states that he referred to the two 1958 Lawrence Livermore National Laboratory clean (low fission) enhanced neutron Plowshare (peaceful explosives) devices by their code names Dove and Starling:

'The first time I recall seeing the term "neutron bomb" was in U.S. News and World Report. This was in May 1959, when the magazine revealed that the U.S. was working on a "neutron 'death ray' bomb which would kill man with streams of poisonous radiation, while leaving machines and buildings undamaged.'

Cohen adds in a footnote on that page that the neutron bomb: 'never did catch on at RAND, which was far more of a campus department than an objective think tank. ... However, I did find out that a good-looking blonde down the hall had expressed interest in hearing my briefing. ... some months later I married her.' On page 61 he explains: 'From the very beginning of the neutron bomb saga there has been one thing that particularly impressed - better yet, depressed - me about renowned American scientists. This is their ability to be impeccably careful and responsible when working in their fields of specilization (if they're not, their colleagues will catch them and even punish them) but their sloppiness and irresponsibility when giving their scientific opinion on nuclear weapons when they have an ideological bias against them, because they know that their colleagues, who share their bias, don't give a damn when they do this.'

Above: Cohen's comparison of the destruction he saw first-hand in Korea from conventional war (1950-3), with the nuclear destruction in Hiroshima. The only difference is that Hiroshima had mainly wooden houses which were burned down, whereas Seoul had more brick and concrete buildings. The Hiroshima photo was taken on 12 October 1945 (U.S. Army Photo #SC 290666); the Seoul photo was taken on 1 November 1950 (U.S. Army Photo #SC 352260).

In 1961, Cohen briefed President Kennedy's national security advisor McGeorge Bundy on the neutron bomb (The Truth About the Neutron Bomb, 1983, pp. 72-3): 'His response was that if we had to use nuclear weapons to stop the Red Army from taking over Europe, he would favor hitting them with the biggest weapons we had. My riposte was: "On our allies' soil?" He didn't reply. ... He had gotten the point. That ended the meeting.' Consequently, President John F. Kennedy authorized the 1963 testing of the neutron bomb underground by Livermore scientists in the Nevada, which 'worked out extremely well' (page 83).

Soviet Premier Nikita Khrushchev fanatically denounced the discriminate neutron bomb in his speech to the Romanian Party Congress in Bucharest: 'More and more frequently now, we hear from statesmen and military leaders, particularly in the United States, that they are working toward the creation of a neutron bomb. ... They are acting on the principle of robbers wanting to kill a man in such a way that his suit will not be stained with blood, in order to appropriate the suit. ... the bestial ethics of the most aggressive representatives of imperialism. ... Man to them is nothing. For them the main thing is to plunder, a quest for profit which prods the imperialists to the most horrible crimes.'

Cohen prints a Dunagin's people satire from 1977, showing a politician ordering physicists to modify the neutron bomb to fit Khrushchev's alleged morality:

'There are strong moral objections to a bomb that kills but doesn't destroy buildings. Fix it so it destroys buildings, too.'

On pages 91-2, Cohen explains: 'A discriminate tactical nuclear weapon is one whose effects can be confined mainly to the military target, minimizing damage to non-combatants and their property. So neutron bombs, which are intended to kill enemy soldiers but spare civilians and their towns, are, by this definition, discriminate weapons. For example, had they been available in the Korean War [which Cohen saw first hand] for use against enemy soldiers fighting in the city of Seoul, their application would have represented a highly discriminate attack - far more so than was the attack that actually took place using conventional weapons, and which pretty well levelled the city.'

He was inspired to invent and promote the neutron bomb by the vast civilian casualties from collateral damage due to the conventional weapons he saw in Korea, and by the NATO 'Carte Blanche' exercise of 23-28 June 1955, which predicted that the 268 nuclear explosions over 3 days in Germany which would be needed to defend Western Europe from Warsaw Pact forces would kill 1,500,000 civilians, and injure a further 3,500,000. By using neutron bomb air bursts (500-1,000 m altitude for 1-10 kt yields), all of these civilian casualties could be avoided. There would be no significant fallout, and the small area of neutron induced activity at ground zero decays very rapidly, as in Hiroshima and Nagasaki. The uselessness of conventional defences to stop massed tank invasions was clearly demonstrated by the French anti-tank Maginot Line, which failed in World War II when Nazi tanks bypassed it and went through the Ardennes Forest to invade France.

On 12 July 1977, President Jimmy Carter publically announced the development of a neutron bomb to deter massed Soviet tank invasions of Western Europe because the Warsaw Pact had 25,000 tanks in Eastern Europe, ready for an invasion. Cohen on page 109 points out that President Reagan in 1981 stated that the Soviet Union responded by pumping over $100,000,000 into an anti-neutron bomb 'peace' propaganda campaign. Premier Leonid Brezhnev offered to refrain from building the neutron bomb if America agreed to do likewise! President Carter responded (Cohen, p. 111):

'The Soviets know and President Brezhnev knows that the neutron weapon is designed to be used against massive and perhaps overwhelming tank forces. ... The neutron weapons are designed to equalize that inequality. ... The Soviets have no use for a neutron weapon, so the offer by Brezhnev to refrain from building the neutron weapon has no significance in the European theatre and he knows this.'

But Carter chickened out when the Soviet anti-neutron bomb propaganda assault on the media commenced. Moscow radio was followed by 28 different European communist parties statements denouncing the neutron bomb as an immoral weapon, and the Soviet funded 'World Peace Council' (similar to Hitler's '25-year-peace plan' propaganda spin before World War II) called a week of international anti-neutron bomb action in August 1977, lying that the neutron bomb was designed to kill civilians and leave cities intact for American invasions and plunder. The pro-communist left-wing media of the West, plus the anti-nuclear biased groups, lapped it all up. Grigori Gokshin, Secretary of the 'Soviet Peace Committee' from 1973-91, conducted war on the neutron bomb through the media to protect the Soviet tank advantage in Europe!

The media pressure, including continuing bias from the BBC, which still falsely claims that horrific fallout and collateral damage was a good thing because it allegedly increased deterrence (in fact, collateral damage potential reduced deterrence by making the threat totally non-credible: as proved by the fact that the Soviets were so fearful of the neutron bomb but were undeterred by nuclear weapons which would produce collateral damage and amassed a tank superiority in the Warsaw Pact for a possible invasion of Western Europe precisely because they knew that indiscriminate American weapons could not be used without millions of casualties, so that such indiscriminate threats had zero, nil, nada, zip credibility as a deterrent to war or aggression), forced President Carter on 7 April 1978 to delay his decision to produce neutron warheads, and although he ordered the production of the fusion capsules for neutron bombs in October 1978, he continued to delay making a decision on the production of the rest of the bomb! (Cohen, page 115.) The next month, Premier Brezhnev responded to Carter's half-hearted decision by telling a group of U.S. senators visiting Moscow that 'many years ago, we tested but we never started production of that weapon'. They didn't want or need low yield anti-tank tactical weapons, because they were the ones with the 4-to-1 tank superiority in Europe! They didn't want or need low yield collateral-avoilding neutron bombs, because they didn't give a damn about civilian casualties and collateral damage. But Premier Brezhnev pretended that the reason they did not have neutron bombs was because they were morally superior!

Carter continued to postpone his decision on the neutron bomb. Undeterred, the Soviet Union in 1979 invaded Afghanistan with tanks in what many considered a forerunner to an invasion of Western Europe and the rest of the free world. President Ronald Reagan was elected, and he ordered the production of 700 neutron bombs (350 nuclear 20-cm diameter shells for howitzers, and 350 W70 warheads for tactical Lance missiles) on 8 August 1981 to help to deter an invasion from the 19,500 Warsaw Pact tanks. Responding on 8 March 1983 to the Soviet 'peace morality' propaganda, Reagan pleaded: 'I urge you to beware the temptation to label both sides "equally at fault", to ignore the facts of history and the aggressive impulses of an evil empire, to simply call the arms race a "giant misunderstanding", and thereby remove yourself from the struggle between right and wrong, and good and evil.'

The neutron bomb is efficient against massed tank invasions, thus an aggressor would be forced to disperse tanks; making them easy for troops to destroy or halt individually using simple hand-launched anti-tank rockets.

Dr Edward Teller and Dr Albert L. Latter were the first to suggest this solution on page 171 of their book Our Nuclear Future: Facts, Dangers and Opportunities, Criterion Books, New York, 1958:

'In a nuclear war it will not make sense to use massed manpower. Any such concentration will provide too good a target for atomic weapons. ...

'Any fighting unit in a nuclear war will have to be small, mobile, inconspicuous and capable of independent action. ...

'If an invader adopts extreme dispersion, it will become impossible to defeat him with atomic weapons. But a very highly dispersed army can be defeated by a determined local population [with hand-held anti-tank rockets, etc.]. Therefore the main role of nuclear weapons might well be to disperse any striking force so that the resistance of people defending their homes can become decisive. Nuclear weapons may well become the answer to massed armies and may put back the power into the hands where we believe it belongs: the hands of the people.'

On page 135 of The Truth About the Neutron Bomb, 1983, Cohen stated that the neutron bomb is inefficient against cities with civilians because: 'All they have to do is construct very simple radiation shelters and, as the eemy approaches, get into them. ... Because there is no blast to contend with ... all that is called for is piling several feet of earth over the shelter. And dirt is cheap.' Earth slows down neutrons efficiently (removing neutron energy) because it contains a lot of light elements, but the heavy iron nuclei in steel tanks don't absorb much energy when they scatter neutrons around, so tanks only have a protective factor of about 2 against neutron radiation (tanks have a protection factor of 10 against initial high energy gamma rays, which are better attenuated by scattering the many electrons in iron atoms).

This is simple physics, but chemist George Kistiakowsky falsely claimed in MIT's Technology Review that 'A 10-cm (about 4 inches) layer of a suitable hydrogenous material, say water in plastic bags over the crew compartment, followed by a thin sheet of cadmium metal, would reduce neutron radiation intensity by about a factor of 5.' A factor of 5 reduction only reduces the neutron range by 15-20% because the dose drops off sharply with distance. But the factor of 5 calculation is false anyway, as Cohen explains on page 142, because the majority of the neutron dose is not coming straight down, but is coming from all directions due to the scatter of neutrons by the air, the ground around the tank, and the remainder of the tank itself! Kistiakowsky's stupidity is like trying to shield gamma radiation from fallout by wearing lead-soled shoes, in the mistaken belief that the hazard is due to fallout under your feet:

'Shielding a tank crew against neutrons is an enormously complicated problem. It is not solved by simply placing the shield over the crew compartment. By the time the neutrons reach the tank, they are bouncing around in all directions, and to protect the crew properly, the shielding will have to be placed around the sides of the crew compartment as well. As a consequence, the shielding weight begins to pile up: to a much greater level than Kistiakowsky realizes. ... The tank's mobility would be cut appreciably, as would the ability to swing the turret around to fire at acquired targets. In fact, were the tank to be shielded to a degree where the radiation was no longer the primary threat ... the added weight would cripple the tank's combat effectiveness.'

Another wild claim against the neutron bomb, made by Dr Herbert Scoville, Jr., which Cohen debunks (page 140), is that tank crews who are lethally irradiated will fight a 'Kamikaze' attack even more efficiently that they were fighting before, despite having radiation sickness. Cohen points out that they will not know exactly what their neutron dose is in a combat situation, and in any case the symptoms of radiation sickness will prevent their efficient execution of military functions.

Cancer and genetic effects are another hoax which was levelled against the neutron bomb: lethally irradiated people don't get cancer (as we shall see, Cohen shows that the effects of radiation sickness are no worse than other lethal combat injuries in modern conventional warfare due to organ damage, burns effects, and so on). In any case, no excess of genetic effects occurred in Hiroshima and Nagasaki as compared to a matched non-exposed control group. For all types of cancers, radiation has only contributed a small fraction of the cancer in survivors, most of which is natural cancer, as shown by comparison with the matched non-exposed control group. Claims that neutron bomb radiation is 'inhumane' ignore the comparison with the organ damage consequences by conventional nuclear weapons (as well as with conventional weapons, which rip organs to pieces, burn, crush and so on), and they ignore the primary purpose of the neutron bomb is to deter an aggressor.

Cohen further points out (pages 153-5) that two radiation accident victims who survived 400-600 cGy air doses (300-450 bone marrow doses): 'were back to normal some number of weeks [discharge from hospital at 2 and 6 weeks, respectively, and full recovery of strength at 10 weeks postexposure] after their accidents. They bore no scars from their mishaps (apparently not even emotional scars) and were able to pick up where they left off when they were irradiated. As to how these aftermaths compare with those resulting from being wounded by conventional weapons, if one so desires you can find out by visiting the nearest Veterans Administration hospital.'

On 11 November 1981, the Los Angeles Times printed an article called 'Neutron Weapons: an Agonising Death (I've seen it)', by Professor J. Garrott Allen at Stanford University Medical School, falsely claiming that the death of Dr Louis Slotin 9 days after a criticality accident in May 1946 indicates the radiation effects of a neutron bomb: 'The production of neutron weapons is probably as immoral a concept as human minds have yet devised.' Cohen debunks Allen on pages 156-7: Dr Slotin was touching a plutonium bomb core with his bare hands when he made it supercritical, so he got terrible localized exposures to his hands and arms, which were way higher than the doses you can get from a neutron bomb. This is why Dr Slotin had the painful radiation burns which Allen observed in treating him. Allen was dishonest in claiming that those radiation burns were analogous to neutron bomb exposures. In any case: 'Allen never mentioned the terrible burns that can result from ... the heat from fission battlefield nuclear weapons.'

On 10 September 1981, two months before Allen's notoriously inaccurate article was published, Cohen had written to the Secretary of Energy James B. Edwards, asking:

'Why is it, Mr Secretary, that after more than four years of intense, often acrimonious and almost always highly emotional, debate over the neutron bomb, the government has never put out an official statement to dispel the distorted technical charges which have been made about the weapon's effectiveness and alleged immorality? It seems to me that had this been done at the start, today we would not have the same anti-nuclear scientists making the same distorted charges; leaving the American people as confused as ever - and probably the Europeans as well.

'I would strongly suggest that DOE and DOD get together (as they did some 30 years ago, when they first issued The Effects of Nuclear Weapons to responsibly inform the American people what nuclear weapons were all about) and provide an official document spelling out the true facts of the issue.' (As we shall see, the declassification of Capabilities of Nuclear Weapons is a step in that direction.)

Above: the 14.8 megatons Castle-Bravo nuclear surface burst on 1 March 1954 at Bikini Atoll, about 20 seconds after detonation. If the Pentagon wanted to kill civilians in a nuclear war, it would have planned to use such nuclear explosions, instead of moving downward to the deterrence of 1 kt neutron bombs burst at 500 metres over Warsaw Pact tank concentrations.

Above: damage to the personnel camp 17 miles away (on the other side of Bikini Atoll), from the 14.8 megatons Castle-Bravo test.

Above: the 3.8 megatons (50% fission) Redwing-Cherokee nuclear test air burst on 21 May 1956 at an altitude of 4,350 feet over Bikini Atoll, having been dropped from a B-52 bomber (the bomb was 34.5 inches wide, 136 inches long, and weighed 6867 lb). This is another way to produce maximum civilian casualties, in contrast to the neutron bomb.

I briefly reviewed the tremendous and excellent autobiography of Sam Cohen, Shame, earlier (click here). The Third Edition has now been released (click here for free PDF book file), with some obvious improvements. Conrad Schneiker kindly emailed the news, stating: 'The third edition features a new overview and postscript chapter by Charles Platt, plus an extremely provocative change of title. (I advised against something so outrageous, but you know how outraged Sam is about current events.)'

In my earlier review I focussed on how the Pope came around to the neutron bomb as a moral step forward in reducing collateral civilian damage in modern warfare by using nuclear weapons with suppressed blast, thermal and delayed effects, but enhanced penetrating initial radiation. The neutron bomb is like the Ark of the Covenant, with its peaceful, deterring rays. Cohen was justifiably awarded the Vatican Peace Medal for his courageous work.
I think the changes are sensible to make any impact whatsoever. There is a lot of coercion for everyone, even the most sensible people in the world - like President George W. Bush - to obey the rules of "Group-Think" (definition: click here). Hence some strong arguments are required to make headway.

What is outrageous is the widely-held belief that dirty, high yield (300-400 kt or whatever) warheads stocked today, which would have fairly massive fallout, blast and thermal implications, are more moral to stockpile as a deterrent than 1-10 kt neutron bombs which are designed for air burst detonation to avert all local fallout hazards, and which release relatively little blast and heat flash since 80% of the energy from deuterium-tritium fusion is released as neutrons.

Obviously there is some fission also involved to start off the clean fusion reaction (but that is trivial for a yield of 1-2 kt, even if burst on the surface or shallow underground to maximise fallout, click here for experimental proof from nuclear tests surface burst, and here for shallow underground test data), and there is also the issue that some soldiers massed in fortifications or fighting vehicles will be neutron targets, but that's the only way to deter them. The public don't understand the fact that the neutron bomb has no collateral damage:

Cohen points out that the neutron bomb doesn't have the collateral damage of fallout, blast and heat effects that occurred in Hiroshima, but enhanced neutron flash radiation:

'in about a thousandth of a second it will seriously irradiate enemy soldiers (in tanks, self-propelled artillery vehicles, armored personnel carriers, in field bunkers, and most other places where they may be) out to a distance of about half to three-quarters of a mile for a warhead yield of a kiloton... Roughly half will die, most rather quickly from shock to the central nervous system. ... What doesn’t it do? Well, for start-offs, when the war is over the civilian areas — villages, towns, cities — will be in just about the shape they were in before it started. There will be no lingering radioactivity [residual doses from neutron induced activity in soil are insignificant compared to the flash dose of neutrons, and it decays quickly as in Hiroshima] to prevent occupation of these areas; in fact, they can be reentered almost immediately. (Compare this with every major war we’ve fought in this century, with what I saw in Seoul that affected me so deeply.)

'As for the enemy soldiers, the bad guys, who during a war we make out to be as barbaric as the troops of Attila the Hun (they usually are), those that die are dead; but that’s always been the main objective in battlefield conflict — to kill. As to how they die, which hasn’t been of real concern in conventional war, all I can say is I doubt whether the agony an irradiated soldier goes through in the process of dying is any worse than that produced by having your body charred to a crisp by napalm, your guts being ripped apart by shrapnel, your lungs blown in by concussion weapons, and all those other sweet things that happen when conventional weapons (which are preferred and anointed by our official policy) are used.' (Shame, online edition, p. 130.) - from earlier review.

'Groupthink is a mode of thought whereby individuals intentionally conform to what they perceive to be the consensus of the group. Groupthink may cause the group (typically a committee or large organization) to make bad or irrational decisions which each member might individually consider to be unwise.

'The term was coined in 1952 by William H. Whyte in Fortune[1]:

'Groupthink ... is a rationalized conformity — an open, articulate philosophy which holds that group values are not only expedient but right and good as well. [2]

'Irving Janis, who did extensive work on the subject, defined it as:

'A mode of thinking that people engage in when they are deeply involved in a cohesive in-group, when the members' strivings for unanimity override their motivation to realistically appraise alternative courses of action. [3]

'Irving Janis originally studied how groupthink affected the Pearl Harbor bombing, the Vietnam War, and the Bay of Pigs Invasion.

'... the Bay of Pigs Invasion as the archetype of the groupthink phenomenon. ... the decision to execute this disastrous military campaign was made with almost unanimous agreement by President John F. Kennedy and his advisors. These advisors were, almost without exception, very similar in background to the President ... General David M. Shoup, Commandant of the Marine Corps at the time and not part of the privileged group, predicted failure and enormous casualties for the invasion, and practically begged the President not to undertake it. Shoup's professional advice was ignored ... with disastrous results. ... In 2004, the US Senate Intelligence Committee's Report on the U.S. Intelligence Community's Prewar Intelligence Assessments on Iraq blamed groupthink for failures to correctly interpret intelligence relating to Iraq's weapons of mass destruction capabilities ...

'Causes and symptoms of groupthink

'Janis's "antecedent conditions" likely to encourage groupthink:

High stress from external threats with low hope of a better solution than the one offered by the leader(s)

High group cohesiveness

The persuasive strength of the group's leader

'His eight symptoms indicative of groupthink:

Illusion of invulnerability

Unquestioned belief in the inherent morality of the group

Collective rationalization of group's decisions

Shared stereotypes of outgroup, particularly opponents

Self-censorship; members withhold criticisms

Illusion of unanimity (see false consensus effect)

Direct pressure on dissenters to conform

Self-appointed "mindguards" protect the group from negative information

'His seven symptoms of a decision affected by groupthink:

Incomplete survey of alternatives

Incomplete survey of objectives

Failure to examine risks of preferred choice

Failure to re-appraise initially rejected alternatives

Poor information search

Selective bias in processing information at hand (see also confirmation bias)

Failure to work out contingency plans

'Social psychologist Clark McCauley's three conditions under which groupthink occurs:

Directive leadership

Homogeneity of members' social background and ideology

Insulation of the group from outside sources of information and analysis ...

'One mechanism which management consultants recommend to avoid groupthink is to place responsibility and authority for a decision in the hands of a single person who makes the decision in private and can turn to others for advice. Others advise that a preselected individual take the role of disagreeing with any suggestion presented, thereby making other individuals more likely to present their own ideas and point out flaws in others' and reducing the stigma associated with being the first to take negative stances (see Devil's Advocate).'

Groupthink is clearly on display in the manner that string theorists operate.

Extract from a previous post on this blog:

Appendix A of the July 2004 Commission EMP report quotes from Thomas C. Schelling's Foreword to Roberta Wohlstetter's book Pearl Harbor: Warning and Decision, Stanford UniversityPress, 1962, p. vii:

'[There is] a tendency in our planning to confuse the unfamiliar with the improbable. The contingency we have not considered looks strange; what looks strange is therefore improbable; what seems improbable need not be considered seriously.'

This is true. Even when Hitler mobilized 100 divisions at the Soviet Union's border in 1941, Stalin was dismissive of all reports of preparations being made by the Nazis to invade the Soviet Union (this was because of the Nazi-Soviet peace-pact of 1939, creating a false sense of security to the USSR). Herman Kahn has explained in On Thermonuclear War (1960) how Pearl Harbor, Oahu, Hawaii (appropriately by coincidence also the centre of unpredicted EMP damage in the 1962 Starfish nuclear test) was supposedly immune from attack, because it was shallower than the textbook-stated minimum water depth for a torpedo. The Japanese simply made special torpedoes to use in the attack on the U.S. Pacific Fleet in 1941. (Even when America received advanced warning of the attack, its wishful thinking simply dismissed the warning as an error, so no warning was passed on, and the scale of the tragedy was maximised.)

From another earlier post:

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. (Published in Radiation Research volume 146:1-27, 1996.)

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 (mainly natural), which is just 428 more than the unexposed control group. Hence, the total increase over the natural cancer rate was 9 %, spread over 40 years.

(Compare these scientific facts to popular fiction in newspapers and widely published political books 'explaining' the horrific effects of nuclear weapons compared to other weapons, which claims there were 100,000 or 200,000 cancers. The real figure is 428.)

From the review of the 2nd edition of Sam Cohen's book:

More on the testing of clean tactical nuclear weapons as low air bursts here (for true air bursts there is no early fallout at all, apart from thunderstorms when it goes straight down the drain anyhow and is shielded underground - it is better to have the fallout underground than people sheltering underground!), surface bursts here, here and here, and shallow underground bursts (for earth-penetrator effects; destruction of buried targets without collateral blast and thermal radiation) see here (scroll down on to section headed 'ARE EARTH PENETRATORS A CLEAN ALTERNATIVE TO HIGH YIELD SURFACE BURST NUCLEAR WEAPONS?'). For it's inclusion by Philip J. Dolan in Capabilities of Nuclear Weapons EM-1, and by Samuel Glasstone in an article in Encarta 97, see here.

A neutron bomb with a thick lead casing will constitute a potential earth-penetrator with greatly suppressed air blast, heat flash, and fallout. The energy of the neutrons will be turned into ground shock effects as they are scattered ('thermalized' to the ambient temperature in the explosion) by the thick casing. The thick casing will pass on ground shock efficiently, using the mechanism discovered by Brode and Bjork of RAND Corp in 1960: 'the primary cause of cratering for such an explosion is not "airslap," as previously suggested, but rather the direct action of the energetic bomb vapors.'

There are therefore numerous uses for neutron bombs in deterring war without risking indiscriminate collateral destruction and the massacre of civilians in the event of an explosion. The 'alternative' is high yield stockpiled warheads!

Update: Samuel T. Cohen, inventor of the neutron bomb, has died

Seen in 1999, Sam Cohen holds up a peace medal given to him by Pope John Paul I. He designed the neutron bomb with just pencil, paper and a slide rule. (San Jose Mercury News)

By Thomas H. Maugh II, Los Angeles Times
December 2, 2010

LOS ANGELES TIMES, Samuel T. Cohen dies at 89; inventor of the neutron bomb

... President Reagan ordered 700 neutron warheads built to oppose the massive Soviet tank force that had been strategically positioned in Eastern Europe. He viewed the bomb as the only tactical weapon that could effectively stop the tanks without also destroying much of the continent. The weapons were later dismantled in the face of widespread protests and the disintegration of the Soviet Union. ...

Samuel Theodore Cohen was born in Brooklyn, New York, on Jan. 25, 1921, to Austrian Jews who migrated to the United States by way of Britain. When he was 4, the family moved to Los Angeles, where his father worked as a carpenter on movie sets. Young Samuel suffered allergies, eye problems and other ailments, and his mother put him on a rigidly controlled diet, regular purges and daily ice-water showers to toughen him up, and fed him so much carrot juice that his skin was often yellow.

A brilliant student, he studied physics at UCLA, receiving a bachelor's degree in 1943. After joining the Army, he was posted to MIT for advanced training in physics and math, then selected for work on the Manhattan Project. Although he never received a doctoral degree, he calculated neutron densities on Fat Man, the bomb that was dropped on Nagasaki, Japan.

After World War II, he joined the RAND Corp. in Santa Monica and spent most of his career there. He said the inspiration for the neutron bomb was a 1951 visit to Seoul, which had been largely destroyed in the Korean War. In his memoir, he wrote: "If we are going to go on fighting these damned fool wars in the future, shelling and bombing cities to smithereens and wrecking the lives of their inhabitants, might there be some kind of nuclear weapon that could avoid all this?"

He designed the neutron bomb using pencil, paper and a slide rule given to him by his father for his 15th birthday.

See also the New York Times,
Samuel T. Cohen, Neutron Bomb Inventor, Dies at 89
Published: December 1, 2010

Samuel T. Cohen, the physicist who invented the small tactical nuclear weapon known as the neutron bomb, a controversial device designed to kill enemy troops with subatomic particles but leave battlefields and cities relatively intact, died on Sunday at his home in Los Angeles. He was 89.

... He insisted that many critics misunderstood or purposely misrepresented his ideas for political, economic or mercenary reasons. ...

A graduate of the University of California, Los Angeles, Mr. Cohen was recruited while in the Army in World War II for the Manhattan Project, which developed the first atomic bomb at Los Alamos, N.M. After the war, he joined the RAND Corporation and in 1958 designed the neutron bomb as a way to strike a cluster of enemy forces while sparing infrastructure and distant civilian populations.

Fired via a missile or an artillery shell and detonated a quarter-mile above ground, his bomb limited death to an area less than a mile across, avoiding wider indiscriminate slaughter and destruction. ... its neutrons dissipated quickly, leaving no long-term contamination that could render entire regions uninhabitable for decades. ...

“It’s the most sane and moral weapon ever devised,” he said in September in a telephone interview for this obituary. “It’s the only nuclear weapon in history that makes sense in waging war. When the war is over, the world is still intact.”

Samuel Theodore Cohen was born in Brooklyn on Jan. 25, 1921, to Lazarus and Jenny Cohen, Austrian Jews who had migrated to the United States by way of Britain. His father was a carpenter and his mother a housewife who rigidly controlled family diets and even breathing habits (believing it unhealthy to breathe through the mouth). The boy had allergies, eye problems and other ailments, and for years was subjected to daily ice-water showers to toughen him up.

The family moved to Los Angeles when he was 4. He was a brilliant student at public schools and U.C.L.A., where he graduated in 1943 with a physics degree. He joined the wartime Army and was posted to the Massachusetts Institute of Technology for advanced training in mathematics and physics.

In 1944 he was tapped for the Manhattan Project to analyze radioactivity in nuclear fission. He worked on Fat Man, the bomb dropped on Nagasaki in 1945, days after Little Boy destroyed Hiroshima.

Mr. Cohen joined RAND in Santa Monica in 1947 and 11 years later designed the neutron bomb as a consultant to the Lawrence Livermore National Laboratory.

His books included “Tactical Nuclear Weapons: An Examination of the Issues” (1978); “The Neutron Bomb: Political, Technological and Military Issues” (1978); “Checkmate on War” (1980); “The Truth About the Neutron Bomb” (1983); “We Can Prevent World War III” (1985); and “Nuclear Weapons, Policies and the Test Ban Issue” (1987). His memoir, “Shame: Confessions of the Father of the Neutron Bomb,” was published on the Internet in 2000.


At 10:49 am, Anonymous Anonymous said...

Copies of some fast comments on Prof Lubos Motl's blog:

The Pope did help defeat communists.

Motl wouldn't be allowed to write what he wanted on his blog if it wasn't for people like the Pope fighting the commies.

The Pope supported peace and awarded the neutron bomb inventor Cohen for deterring the 3-to-1 Warsaw Pact tank superiority in England.

Dear N,

I am still grateful to John Paul II for various things, but the communism in Czechoslovakia was primarily defeated by the Czechoslovak students like me and those who followed. It is not quite clear to me what mechanism are you imagining in Pope's victory over communism, except for his prayers.

Lubos Motl | Homepage | 06.17.06 - 9:11 am | #

Dear Lubos,

The mechanism: in 1979 the communist power was at its highest, they had achieved nuclear parity with the West and they invaded Afghanistan.

The Pope - unlike predecessors - took a strong line against it. Giving Cohen a medal for peace is not the mechanism I mean. Reagan deployed the neutron bomb in Western Europe.

The Warsaw Pact was already under enormous financial burdens.

Capitalism defeated communism by outspending on arms to deter them. This required the moral backing of the Pope, who was from Poland (which is probably more grateful than Czech Republic). Reagan sparked off the need for economic reform not only with neutron bombs but by "starwars" etc.

This means that they gave up trying to win the Cold War, and Gorbachev came to power to reform the commie economy and try to make consumer goods and sort out food shortages.

As soon as Gorbachev relaxed state police power in the Warsaw Pact, communism was able to collapse.

If the background situation was not relaxed as a result of the Pope and others condemning communism and supporting the arms race against it, it could have won.

Student protests are not going to be effective unless the regime is demoralized and relaxing its iron grip first as shown by the earlier failure in Prague, Czechoslovakia in 1968 and in other states where students were simply driven over by tanks or guns. (Hungary 1956, Tiananmen Square, China 1989.)

It was only because the Pope and Reagan had used the arms race to force economic reform on Gorbachev that you Czech students did not have to face the tanks of the Red Army.


At 6:15 pm, Blogger nige said...

Copy of a comment to

Hi Kea,

Lubos Motl is right about the climate change manure because what the doom-sayers of climate change forget is that we're running out of fossile fuels anyhow!

Before the world is wrecked completely by global warming, we'll have run out of oil, coal, gas (North Sea oil is far more expensive than Arabic supplies because of the costs of oil rigs in the North Sea, and gas - "vapour" I suppose to USA readers to avoid confusion with gas(oline) - is seriously more expensive now that the market is opened up to Europe by a new gas pipeline, and if I buy a new home I'm getting all-electric heating, not the traditional piped gas heating currently used in most of the UK).

To combat global warming, go nuclear. Nuclear is clean, safe, and it is EVEN ECONOMICAL if you lower radioactive pollution horseshit propaganda and shoot crackpots who claim radiation is lethal.

Those people don't understand background radiation, or the effect of higher altitudes, air travel, etc on radiation exposure.

They think "natural" radiation is safe and "artificial" radiation from nuclear power is totally different.

The Health Physicists who work in the nuclear industry are a load of gormless, feeble, patronising fools who couldn't explain anything to anybody without making it sound like condescending pro-nuclear propaganda, which is why the situation continues.

They have no idea that physics and maths are well known, and that people can by and large understand radiation. They perpetuate the myths.

The FIRST thing physicists in the f***ing nuclear industry should put on their posters is the fact that on the Moon the natural radiation is 50 times higher than on earth, 1 mR/hr on Moon compared to 0.02 mR/hr on Earth (the earth's atomsphere shields most of the background radiation, which is 99% protons and alpha particles).

Then they should give the ACTUAL (not relative!) natural dose rates in different cities with different bedrocks and altitudes above sea level! The thorium rich beach sands of Brazil and India are more radioactive than 90% of the "nuclear waste" from the nuclear industry!

It is a wide range!!! Then, finally, they should show the lies about low level radiation by plotting the mortality in Hiroshima and Nagasaki and other long-term reliable studies as a function of dose.

It is true that massive doses severely increase leukemia rates, but it is a lie that small doese do so in proportion, or that other cancers are increases in the same way. Leukemia is a special problem, because the bone marrow is very susceptible to ionising radiation.

Particularly, high-LET (linear energy transfer) radiations like alpha and beta and also soft x-rays (which cause ionisation by the photoelectric effect) inside the body increase cancer risks, NOT low-LET radiation like gamma rays (unless the dose is really massive).

People should be aware that the more penetrating the radiation is, the less of it gets stopped by soft tissue in the body, so the LOWER the absorbed dose per unit of fluence!

The real dangers from low level radiation are from ingesting or inhaling soluble alpha and beta emitters, like radium and strontium-90 respectively, which get deposited in bone and can cause leukemia. Radon gas from the decay of radium is also a massive natural hazard, killing far more people than all the hundreds of megatons of 1950s nuclear tests or Chernobyl.

Chernobyl showed that iodine-131 causes a short term problem (half like 8 days) after an explosion, because it gets concentrated in milk and then in kid's thyroid glands and can cause lumps (mostly benign). The answer is simple: for the few weeks while milk is contaminated, either put it through an ion-exchanger to remove the iodine-131, or switch to using powdered milk or simply put the cattle in winter barns eating winter feed like hay so that they don't eat contaminated grass! Problem sorted!

See for more info on this!

Regards Hiroshima and Nagasaki long-term radiation effects cover-up, see links on

Fewer than 1% of victims died due to cancer caused by radiation!!!!!

The maximum leukemia rate occurred in 1952 and ever since has been declining. There were no genetic effects above the normal rate in offspring of even highly irradiated survivors and cancer risks were carefully studied:

'The Life Span Study (LSS) population consists of about 120,000 persons who were selected on the basis of data from the 1950 Japanese National Census. This population includes ... atomic-bomb survivors living in Hiroshima or Nagasaki and nonexposed controls. ... all persons in the Master Sample who were located less than 2,500 meters from the hypocenter ATB were included in the LSS sample, with about 28,000 persons exposed at less than 2,000 meters serving as the core. Equal numbers of persons who had been located 2,500-9,999 meters from hypocenter ... were selected to match the core group by age and sex. ... As of 1995, more than 50% of LSS cohort members are still alive. As of the end of 1990, almost 38,000 deaths have occurred in this group, including about 8,000 cancer deaths among the 87,000 survivors. Approximately 430 of these cancer deaths are estimated to be attributable to radiation.'

More here.

Sorry to go on, but all this environmental crackpottery just drives me nuts.


At 6:52 pm, Blogger nige said...

Copy of a comment

"By an amazing coincidence, the configuration resembles a peace symbol with Earth at its centre."

Yes, it's the CND symbol, invented in by Gerald Holtom for the march of the Direct Action Committee Against Nuclear War from London to Aldermaston, Easter 1958.

CND was unfortunately debunked as being largely run by Moscow-funded 'World Peace Council' Soviet communists, by Paul Mercer's book, “Peace” of the dead: The Truth Behind the Nuclear Disarmers (London, 1986). The worst thing about the Soviet/CND 'peace offensive' attacking civil defence precautions by making false claims about the effects of nuclear weapons, and also the effect it had on Samuel Cohen's invention of the neutron bomb to stop wars and to stop reliance on high yield nuclear weapons, which can cause collateral damage to civilian areas nearby.

I think it's a good thing to have peace, but there are issues about how best to get there. (Simple disarmament was tried in Britain in the 1920s and 1930s, but it just encouraged enemy aggression.)

At 6:24 pm, Blogger nige said...

Update 15 May 2007: there is an interesting interview of Samuel Cohen by the Wired journalist Charles Platt, "The Profits of Fear", where Platt admits:

"... Journalists were not much better. They could have learned the ethical basis for the neutron bomb easily enough if they cared to do so, but, they didn't care. They took the lazy way out, quoting cheap shots from peace activists' press releases, which never failed to tag the bomb as the "ultimate capitalist weapon." Cohen took grim solace when Leonid Brezhnev denounced him publicly as an "international war criminal," but the vilification he received in his own country was hard to endure.

"Confronted with bad press, venal politicians, and world leaders who still seemed hooked on the drama of weapons that would cause as much destruction as possible, Cohen concluded that neutron bombs would be built only if the United States got itself into a conventional war that imposed an intolerable financial burden while creating unacceptable casualties among American troops. As the years passed, the Vietnam War certainly began to fit this description. "We had close to a half million American casualties in Vietnam," Cohen recalls, "and by this time the Livermore laboratory had put in a proposal to Washington stating that they could manufacture a couple hundred neutron bombs. Of course, no one can predict the number of bombs that would produce any specific result, but I believe that considerably less than 200 neutron bombs could have ended that war."

"Since an outright retreat from Vietnam seemed unthinkable at this time, the situation invited a quick application of overwhelmingly superior military technology--which could now be achieved without targeting civilians or destroying the infrastructure that sustained them. Once again, however, Cohen found himself thwarted by theories and prejudices that made this unacceptable. The neutron bomb was still nuclear, the Vietnamese were Asian, yet even this wasn't the biggest issue. According to conventional wisdom, any small nuclear weapon was dangerous because the nation that used it would encourage other nations to use theirs, and a back-yard nuclear squabble would escalate to a full-scale nuclear war.

"This was like the theory that anyone who used marijuana would wind up using heroin. No evidence existed to support it. No national leader had ever threatened to respond with a big nuke if someone else launched a small one. Still, everyone was afraid that it could happen, and Cohen couldn't prove that it wouldn't."


There is a printable PDF version at

At 5:53 pm, Anonymous Anonymous said...

Is there exist limit on size of H-bomb?From Brief story of time:
Such conditions could occur in a very big hydrogen bomb: the
physicist John Wheeler once calculated that if one took all the heavy water in all the oceans of the world, one could
build a hydrogen bomb that would compress matter at the center so much that a black hole would be created. (Of
course, there would be no one left to observe it!).So what type of tamper he consider ?Mass of uranium on Earth not enough to compress ~4.8*10^13 tons of deuterium.How many stages this would be? Its evidence that multi-stage designs have far better yield-to weight ratio than smaller ones.Another side: George Dyson when he described USAF Doomsday Orion proposal in BBC doku:To mars by A-bomb says that its bomb (1650 metric tons) largest physically possible.What this mean?Probably this bomb would have largest physically possible yield-to weight ratio for tn-weapons(~100 megaton per ton)?Idea was to detonate this at very high alltitude (~400km) at Soviet Union,this would spread fires over entire hemisphere and probably destroy ozone layer.Gold is better for compression than uranium?What this fireball would be ,X-ray-fireball ?Probably fireball would be spread over entire hemisphere.

At 8:11 pm, Blogger nige said...

Yes, you can distil deuterium from sea water and in principle use it to make an arbitrarily large explosion. Regarding the problems of using a small fission bomb to compress and ignite the (extremely large) deuterium capsule in such a design, there are two obvious possibilities:

(1) You just make the deuterium capsule a very long cylinder (along its long axis), and put the small fission bomb at one end. The X-rays can't ablate and compress the entire long secondary simultaneously, but they will get the reaction started for the first few feet length near one end of the cylinder. The fusion energy released at that end will be accompanied by X-rays, which will ablate and compress the next few feet of the length of the deuterium cylinder's metal pusher, and so on, like the burning of a fuse. The efficiency will be expected to increase as more and more deuterium is fused.

(2) Another obvious possibility is a "Russian doll" design. Here you have only one fission stage, but you have lots of cases of increasing sizes with increasingly sized separate deuterium stage capsules in each case, all within one another. So you start with a normal two stage Teller-Ulam thermonuclear bomb with just a normal megaton or whatever sized fusion secondary, complete with outer casing. Then you take that entire bomb (with its case) and use the whole thing exactly like a a "primary" stage, inside another bigger bomb, which also has its own fusion secondary stage and its own outer casing. Then you take that entire "Russian doll" bomb, and use it as the primary stage for still another even bigger bomb, and so on. This way, can start with just the 2 kg or so of fissile material required for a single kiloton fission primary and work up in stages to achieve an effective "primary" as big as you want, without using any more fissile material. All of the secondary stages can just use deuterium (in an ablative casing of depleted uranium, thorium, lead, or whatever).

Herman Kahn discusses these ideas under the category "doomsday machines". However, they are undeliverably heavy, exceedingly expensive (deuterium is very expensive to distil in massive amounts, it's not as free as the sea water which contains it; sea water also contains gold but it's not worth the expense to extract it except as a byproduct of some desalination plant operations), and unpractical for military purposes. Maybe the long-line version (type 1 above) could be useful for economically digging a very long, very big, extremely deep canals, making huge tunnels through massive mountain ranges, and similar geophysical engineering, once the current nuclear hysteria in the media dies down a little. The other design could be used for really huge "orion" type nuclear explosion pulse accelerated spacecraft.

At 9:12 pm, Anonymous Anonymous said...


As for histeria-I'm completely shocked not only histeria by media,but "works" by FAS staff (Kristenson) and his comrades in NRDC.
They give initially absurdly small yields
for some US weapons(this was corrected in 2009) ,but 1.1 mt yield for mk28Y1(strategic version)was a yield of clean version,est.yield prior test was 800kt,but this is only 1/5 of full yield.Also numbers,it seems that numbers of mk39-s and mk-41-s were higher than 700 and 500 respectively.Initial plan for mk41s would be as high as number of heavy bombers*2,but in 1960 under pressure of some Joint Chiefs of Staff Eisenhower approved replacements of loadings-prior each bomber carry 2 type B ,after this was a mix of B and D (4 per bomber)+Hound Dogs were deployed ,however only 54 by end of 1960.But ,it seems that number of mk-41s was somewhat larger.

Another ,their's constant false -absurdly exaggeration of effects,totaly using Postol's falsehoods,lying about impossibility of missile defence and etc.They finally claimed that ....... 368 w-88 airbursts required to kill............25% population of China.They against any new weapons and scientific work on its and related technologies,for complete eliminations of nuclear weapons as soon as possible,this would be a mistake.I'm believe that China since 2025 would be a very big problem.

At 3:33 pm, Blogger nige said...


What annoys me about NRDL is that they got the 1992 version of Brode's "Capabilities of Nuclear Weapons" declassified under the freedom of information act, as William Arkin reported in the July 1997 Bulletin of Atomic Scientists, and now they are sitting on it, effectively keeping it secret! When will they digitalize it and put it online as a PDF file?

Also, the volume of the NRDL "Nuclear Weapons Databook" on British nuclear weapons is completely wrong. They claimed the first British thermonuclear test Short Granite was not a radiation-coupled separate stage device but a layer cake (a spherical design with lithium deuteride packed around the fission core), when in fact it was a two stage device. The failure to achieve a high yield was due to Taylor instability in the poorly designed secondary stage. This is made crystal clear in the detailed description of the device by the actual designer, reprinted as an appendix to "Britain and the H-Bomb" by the official historians, Lorna Arnold and Katherine Pyne (2001).

Britain’s first hydrogen bomb test, Short Granite, had a fusion stage physically separate from the 30-kt fission stage, but the fusion charge was a spherical layer cake; it had 14 concentric layers 0.86 mm to 2.47 cm thick, alternately lithium-6 deuteride and uranium-238. Dr William Penney designed the first version of this bomb in September 1955, as two spherical units, a fission bomb and a fusion charge, within a single cylindrical bomb casing. Penney’s design only yielded 300-kt when tested on 15 May 1957, because the 14 thin shells of uranium and lithium deuteride were too thin to allow fission and fusion reactions. Where they were mixed up by instabilities during compression, the resulting mixture prevented fusion reactions.

However, this low yield was sorted out by redesigning the spherical secondary (fusion) stage so that it contained a small U-235 core surrounded by just one thick lithium-6 deuteride layer and finished with an outer shell of U-238. This redesign was tested on 8 November containing a 45-kt fission primary with a beryllium reflector and yielded 1.8-Mt.

At 3:33 pm, Blogger nige said...

Lorna Arnold, the official historian of Britain’s nuclear tests, states in the book Britain and the H-Bomb (Palgrave, New York, 2001, p. 160) that in the fission primary the chemical explosive implosion system took 70 microseconds (from electrical detonation time) to achieve maximum compression of the plutonium core. Arnold states that the x-ray energy it released compressed the fusion stage diameter by 2.7 times, thereby increasing its density by 20 times within a time of 2 microseconds. This is to be compared to a maximum density increase of only 8 times in the much smaller fission core. It is interesting that the same bomb materials were rearranged to give another design with the fission and fusion stages placed closer together (almost touching), and this was tested with a yield of 3-Mt on 28 April 1958. This design was only 3.2 metric tons and therefore gave nearly 1-kt/kg. It was manufactured as Yellow Sun Mk1 and was stockpiled by the RAF from 1959-62.

Closer spacing of the two stages therefore increased efficiency and thus the yield of the weapon by 67 %, instead of reducing the yield by causing the shock to upset the fusion stage (as you might expect). The speed of the x-ray mechanism is so much faster than the material shock wave, that the latter can be forgotten in the design process. In the 1950s American thermonuclear weapons, the secondary charges were cylinders, not spheres as used in British weapons. The American W-28 weapon uses a tapering cylinder, which is widest near the fission bomb, but becomes narrower at greater distances to allow for the fact that the x-ray intensity falls with distances so the parts of the fusion stage further from the fission bomb get less compression force. To keep the compression factor constant, the fusion charge cylinder must become narrower with increasing distance from the x-ray source.

After the exchange of American-British research on nuclear weapons in 1959, America developed the W-50 warhead that contained a 410-kt nuclear explosive with a spherical second stage like the British devices. The W-50 nuclear component mass was 186 kg, 1.12 m long and 39 cm in diameter. It was first tested as Aztec on 27 April 1962, and was also used for the high altitude tests that same year, Kingfish and Bluegill. America also used spherical fusion stages in its most recent warheads, the W-87 and W-88 (their blueprint schematics were released after Dr Wen Ho Lee allegedly emailed them to communist China). The W-87 is very similar to the classic British thermonuclear design, with a spherical fission bomb beside a spherical fusion charge containing a U-235 core surrounded by a shell of lithium-6 deuteride, and topped off with a U-238 pusher. The W-88 is somewhat different in that it uses a prolate-spheroid shaped implosion fission bomb, and the fusion charge differs from that in the W-87 because it contains a U-235 pusher instead of U-238.

At 3:38 pm, Blogger nige said...

Sorry, I mean NRDC not NRDL in the comment above!

At 9:29 pm, Anonymous Anonymous said...

It seems fo me that Soviet tsar bomb was a not 3-stage device,but a cluster of smaller ones(probably 8*12.5Mt).
Soviet Union never considered this as weapon,one proposal was for using its as mine.They considered 30mt and 50mt for UR-500 and R-56 respectively,however later canceled this.See:Khrushchev, Sergei, Nikita Khrushchev and the Creation of a Superpower, Pennsylvania State University, 2000. I believe this book a best source on soviet weapons and plans to 1965.For later weapons, mostly ICBM warheads i believe reliable data not exist in declassified world.

At 11:53 am, Blogger nige said...


Modern compact MIRVed ICBM warheads like the W87 and W88 have to use spherical/prolate shaped secondaries as is made clear by the unclassified Cox Report on the Wen Ho Lee warhead blueprint leaks.

These spherical shaped secondary stages were first tested in the 1950s by Britain, which declassified the technical details for Arnold's published official history of British research on the H-bomb.

Therefore, there is some information available. Like Dolan's 1972 EM-1, Bridgman makes the point very clearly in his 2001 DTRA book, Introduction to the Physics of Nuclear Weapons Effects that civil defense countermeasures depend on an understanding of the general construction of different kinds of nuclear weapons (pure fission, boosted, gun assembly, and different kinds of thermonuclear weapons like neutron bombs, etc.), because the weapon design determines (1) the output of initial nuclear radiation, which is a key casualty causing agent for low yield weapons once you duck and cover from the thermal flash, blast winds, and flying bebris, (2) EMP (which depends primarily on the prompt gamma output, which depends on the inelastic neutron scatter in the bomb materials, the fission yield, and the bomb outer casing shielding factor), and (3) fallout (neutron induced activities like U237 and Np239 from neutrion capture by U238 greatly affect fallout radiation rates and gamma spectra, so the shielding protection factor during the first few weeks depends critically on bomb design, the kind of tamper or pusher, etc.). Hence the threat from fallout depend on the bomb design; early relatively clean bomb tests in 1956 (Redwing-Navajo and Redwing-Zuni) for example used lead pushers which led to neutron induced lead nuclides in the fallout, while later relatively clean bombs tested in 1958 and later used tungsten pushers, leading to important contributions to fallout radiation by tungsten nuclides due to neutron capture in the tungsten. Tungsten is preferred to lead for use as an ablative pusher because it has nearly double the density of lead and is roughly the density of uranium (specific densities for uranium and tungsten are around 19 grams per cc, compared to only about 11 for lead).

So for real appreciation of civil defense, you need an up to date understanding of bomb design implications for the INR, EMP and fallout effects.

At 8:35 pm, Anonymous Anonymous said...

Redwing-Zuni was a clean version of Bassoon device ,its full yield was a 25mt,later deployed as mk-41.

Poplar device was not related to mk-41,its was another device for class B weapon.Its full yield was 20 mt,test yield of clean version was predicted to be a 7mt,in reality-9.3mt.Probably clean version was considered as addition to mk-41,since as its clean version was only 3.5mt.However never deployed.In reality a large number of devices(both 2 and 3-stage) was studied both by LANL and LLNL for new class B warhead (20Mt,10000 pounds).But Bassoon device was a cheapest .And most probably its enlarged version was considered as basis for new Class A weapon(25000 pounds,60Mt).

At 7:41 pm, Anonymous Anonymous said...

What would be smallest possible ratio of u-238 casing mass/fusion fuel mass ?And gold as tamper is better than u-238?

At 12:59 am, Blogger nige said...

You don't need any U-238 in the casing at all. Redwing-Navajo tested at Bikini Lagoon in 1956 had a lead tamper in place of U-238. Total yield 4.5 Mt and fission fraction was 5% or 225 kt, which must have been the yield from full fission of the primary stage. It can't have contained any significant fission "spark plug" in the fusion stage. It still worked fine. Obviously, the heating of the secondary (fusion) stage is reduced by the removal of the fission of a U-238 tamper or pusher around it. So replacing U-238 with lead or tungsten must reduce the efficiency of the fusion reaction, requiring a heavier bomb for the same overall yield.

Ordinary stable gold or Au-197 has a density of 19.32 g/cc, which is similar to uranium.

The neutron capture cross-section for this stable gold Au-197 is only 0.09 barn for 1 MeV fission spectrum neutrons, but seems to drop to about 0.01 barn at 5 MeV and presumably less at higher (fusion neutron) energies, according to Fig 1 in the 1976 translated Russian report I'm not near a library that has the Chemical Rubber Company (CRC) reference work, CRC Handbook of Chemistry and Physics, which is usually the best handy compilation of nuclear data on all the different isotopes, so I can't check that or find out what the neutron inelastic scatter cross-section for gold is. Two 1956 clean (5% and 15% fission) Redwing tests both used lead tampers, while the clean American tests in 1958 and 1962 both used tungsten pushers (tungsten is better than lead, since it has a much higher density).

Gold has the obvious disadvantage of being expensive. Normal tungsten, which is mainly W-184, is much cheaper than gold. Tungsten has of course a very high melting point, 3410.0 °C which is why it is used in light bulb filaments (the melting point is much higher than ordinary silicate soil), so it's neutron capture derivatives behave as super-refractory or "enriched" nuclides in early fallout from surface bursts. However, this doesn't matter for air burst neutron bombs.

At 7:47 pm, Anonymous Anonymous said...

It seems that this device that Hawking mentioned and Wheeler studied-largest physically possible Teller-Ulam bomb.Probably Wheeler's goal was to determine upper limit of Teller-Ulam design.

It interesting to estimate its yield,since as deuterium burning would be only first stage ,later helium burning, carbon burning and etc.And other means,such as plasma would be very high-energic.and heavy.

At 8:52 am, Blogger nige said...

Hi Anonymous,

"It interesting to estimate its yield,since as deuterium burning would be only first stage ,later helium burning, carbon burning and etc.And other means,such as plasma would be very high-energic.and heavy."

Again, please use space after comma or full stop.

Regarding your joke. No, I'm not that stupid. I've read Glasstone's Controlled Thermonuclear Reaction and I know how the sun works - SLOWLY!!!!

Even under the immense compression of the sun's mass and gravity, the nuclear fusion reaction rate per particle is extremely low. This is why it lasts billions of years.

There is no way you are going to burn helium or carbon or anything heavier!

Carbon burning requires the triple alpha process: three helium-4 nuclei have to come together (fusion can't proceed effectively by purely binary processes beyond beryllium, due to a bottleneck in the chain). There is no way you can achieve any efficiency with this process over the timescale of a nuclear explosion.

You're talking about building a new star, a new sun, not a bomb.

True, old heavy stars can explode with a supernova. Betelgeuse, 640 light years away, is supposed to have gone supernova around 1370 AD and its flash is predicted to be seen this year, if they have their sums right.

However, supernovae require immense masses so that a heavy core builds up, creating very heavy elements by successive neutron captures (the R or rapid process), right up to uranium and plutonium. People are never directly going to make exploding star. Maybe eventually there will be robot spacecraft like giant dumper trucks in space that can pile together material to make stars and supernovae, but that's so far off we don't need to worry about it. No terrorist is going to do it in their back room!

At 9:00 am, Blogger nige said...

Earth 'to get second sun' as supernova turns night into day
By David Gardner
Last updated at 5:53 PM on 22nd January 2011

The Earth could soon have a second sun, at least for a week or two.

The cosmic phenomenon will happen when one of the brightest stars in the night sky explodes into a supernova.

And, according to a report yesterday, the most stunning light show in the planet’s history could happen as soon as this year.

Cosmic phenomenon: The Earth could soon see two suns - just like Luke Skywalker saw on Tatooine in the Star Wars film (pictured)

Earth will undoubtedly have a front row seat when the dying red supergiant star Betelgeuse finally blows itself into oblivion.

The explosion will be so bright that even though the star in the Orion constellation is 640 light-years away, it will still turn night into day and appear like there are two suns in the sky for a few weeks.

The only real debate is over exactly when it will happen.

In stellar terms, Betelgeuse is predicted to crash and burn in the very near future. But that doesn’t necessarily mean you have to rush out and buy sunglasses.

Brad Carter, Senior Lecturer of Physics at the University of Southern Queensland in Australia, claimed yesterday that the galactic blast could happen before 2012 – or any time over the next million years.

‘This old star is running out of fuel in its centre,’ Dr Carter told te Austalian website

‘This fuel keeps Betelgeuse shining and supported. When this fuel runs out the star will literally collapse in upon itself and it will do so very quickly.

‘This is the final hurrah for the star. It goes bang, it explodes, it lights up - we’ll have incredible brightness for a brief period of time for a couple of weeks and then over the coming months it begins to fade and then eventually it will be very hard to see at all,’ he added.

Look out: Betelgeuse, which is in the Orion constellation, is set to blow itself into oblivion - which will give the effect of two suns in the sky for us on Earth

The Internet is abuzz with doomsday theories linking the supernova to the Mayan calendar’s prediction of an Armageddon in 2012, fuelled by the association of the word ‘Betelgeuse’ with the devil.

But experts claimed that even if the big bang is looming, it will still happen way too far from Earth to do us any harm.

‘When a star goes bang, the first we will observe of it is a rain of tiny particles called nuetrinos,’ said Dr Carter.

‘They will flood through the Earth and bizarrely enough, even though the supernova we see visually will light up the night sky, 99% of the energy in the supernova is released in these particles that will come through our bodies and through the Earth with absolutely no harm whatsoever.’

When it happens, the Betelgeuse supernova will almost certainly be the most dramatic ever seen.

It is the ninth brightest star in the night sky and the second brightest in the constellation of Orion, outshining its neighbour Rigel – or Beta Orionis – only very rarely.

It’s distinct orange-red colour makes it easy to spot in the night sky.

If it was at the centre of our solar system, its surface would extend past the asteroid belt, wholly engulfing Mercury, Venus, Mars and the Earth.

At 9:12 am, Blogger nige said...

There are a couple of minor flaws in the newspaper story just quoted about the forthcoming Betelgeuse supernova. First, it's not proved exactly what the effects will be. Even very weakly interacting particles like neutrinos (misspelled in the article above) can kill you if you get a massive dose. Normally, astronomers see supernovas billions of light years away. This one will be only 640 light years away, that we know for sure. If you do the inverse square law to compare the radiation dose from a supernova 640 light years away to 1,000,000,000 light years away, (1,000,000,000/640)^2 = 2.4 * 10^12. So it's a million million times stronger. The supernova continues radiating radiation at a high rate for days, so it's not just the people on the side facing the initial flash who are exposed.

I'd like to check actual dose estimates, with error limits, before agreeing that we are safe from such a relatively nearby supernova just 640 light years away. People can be protected in principle by the earth's mass, by staying on the opposite side of the earth (in an aircraft flying against the direction of the earth's rotation).

Another thing is the date of the supernova. They can't be sure exactly when it will blow.

At 9:14 am, Blogger nige said...

Of course neutrinos can't be efficiently shielded by the earth's mass because they are so extremely penetrating, but the light velocity gamma radiation and slower moving charged particle radiation (which will take years to arrive) can be efficiently shielded this way.

At 9:22 am, Blogger nige said...

It's usually believed that a supernova would need to be within 25 light years of us to kill everyone by muon radiation, but there are various assumptions in the calculations that leave some questions unanswered. :

The red giant Betelgeuse, once so large it would reach out to Jupiter's orbit if placed in our own solar system, has shrunk by 15 percent over the past decade in a half, although it's just as bright as it's ever been.

"To see this change is very striking," said retired Berkeley physics professor Charles Townes, who won the 1964 Nobel Prize for inventing the laser. "We will be watching it carefully over the next few years to see if it will keep contracting or will go back up in size."

At 9:45 pm, Anonymous Anonymous said...

This is not joke.
In sun pressure only -2.4*10^16 Pa, density- only 150g/cc.
To reach a BH density in this bomb (assuming mass of U-238 tamper -4*10^15 tons)density must be at least ~10^40g/cc,pressure-10^53Pa,T=10^19K or 10^6Gev.Matter would be crushed to pre-quark level. Even in core of neutron star-pressure-10^33 Pa,density-10^14g/cc, T=10^12K or 100 Mev. In 25 solar mass type II supernova silicon burning occurred at density-10^8g/cc, T=2.5*10^9k,with duration of 5 days. Very large stars with mass larger than 260 solar masses directly collapse in black holes and generate 10^54 erg jets. There explosive Si and O burning and far greater pressures than in ordinary supernovas. But in this device density far larger than in above examples, far larger than it needed to burn any element. In certain conditions slow processes would be very fast.

At 5:41 pm, Anonymous Anonymous said...

"1.1 Primordial Black Holes
We now have good observational evidence for black holes from stellar masses up to
super-massive holes of 108 to 1010 solar masses and maybe even more. However,
one can also speculate on the possible existence of black holes of much lower mass.
These are the holes for which quantum effects can be important. Such holes could
not form from the collapse of normal baryonic matter because degeneracy pressure
will support white dwarfs or neutron stars below the Chandrasekhar limiting mass.
One can express this limiting mass as mPlanck(mPlanck/mbaryon)2. Its value is about a
solar mass, which might seem a coincidence, but there are good anthropic principle
reasons why stars should be just on the verge of gravitational collapse.
This limiting mass applies only to the formation of black holes through the
gravitational collapse of fermions. In the case of bosons the limiting mass is given
by mPlanck(mPlanck/mboson). To form a black hole by the gravitational collapse of
bosons, they need to have a non-zero mass and either be stable or have a fairly
long life. About the only candidate is the axion, which might have a mass of about
10−5eV. In this case the limiting mass would be about the mass of the Earth,
which is still quite high, and too large for quantum effects to be observable. To
get black holes that are significantly smaller, one could not rely on gravitational
collapse, but would have to shoot matter together with high energies. John Wheeler
once calculated that if one made a hydrogen bomb with all the deuterium from
the oceans, the centre would implode so violently that a little black hole would be
formed. Perhaps fortunately, this experiment is unlikely to be performed. Thus the
only place where tiny black holes might be formed is the early universe."
From paper:S.W.Hawking and R.Bousso,Primordial black holes :Tunneling vs.No Boundary Proposal.
at ArXiv:gr-qc/9608009
Even my estimates would be very conservative.

At 8:58 pm, Blogger nige said...

Hi Anonymous,

Hawking produces a lot rubbish based on first-quantization, such as his false claim that black holes should radiate irrespective of their charge.

Black holes are a very convenient hiding ground for egotists who don't want to understand physical mechanism.

Disproof of Hawking's general claim that black holes radiate

Schwinger in 1948 showed that pair production doesn't occur throughout the vacuum of space, but in electric fields >1.3*10^18 volts/metre. This threshold for pair-production is vital for vacuum polarization to stop varying the electronic charge below the IR cutoff in 2nd quantization (QFT), so it destroys Hawking's heuristic explanation for Hawking radiation from uncharged black holes.

The mechanism is that pair production occurs at the event horizon, with one fermion in the pair falling into the black hole, and the other escaping and eventually annihilating with an opposite charge to give a gamma ray (nobody has ever seen this alleged gamma radiation from a black hole, it's conveniently too small to observe above the gamma ray background in space from other sources!).

My argument using Schwinger's 1948 discovery in QFT black holes cannot radiate electrically neutral radiation such as gamma rays. Hawking's heuristic mechanism is false, because you need an electric field above 1.3*10^18 v/m at the event horizon, which means the black hole must be electrically charged in order to radiate anything by Hawking's heuristic mechanism. Things don't happen without a mechanism in QFT.

So uncharged black holes have 0 v/m electric field at their event horizons and emit no gamma rays (Hawking radiation), because there's no pair production there.

If we instead model a fermion as a charged tiny black hole, then it turns out that the electric field strength at its event horizon radius (2GM/c^2) is above the Schwinger's threshold for pair-production, so in this case Hawking's heuristic black hole radiation mechanism (albeit in modified form) does operate: the fermion will radiate charged virtual fermions as radiation, and these virtual fermions will have a charge the same sign as the real fermion in the core (the virtual fermions of sign opposite to thet of the real fermion core will fall into the black hole core). The interesting thing here is that two similar charged fermions travelling in opposite directions cancel one another's magnetic field vectors and thus cancel out the magnetic self-inductance that would otherwise prevent propagation. So massless off-shell (virtual) fermions can be exchanged between similarly charged particles, so that there is an equilibrium of exchange radiation. In this way, you can have charged fermions moving in opposite directions superimposing to create a composite field which is similar to a charged boson. I.e., the opposing half integer spins of each component can add to give bosonic spin.

At 3:42 pm, Anonymous Anonymous said...

Hello Nigel!

In fact there not a Brief History of Time was a first mentiotion of this Wheeler's calculation(simulation) This was a :
William J. Kaufmann, "Observing Astronomers: An Interview with Dr. Stephen W. Hawking"; Mercury 4 (November/December, 1975):13-16.

There was before Morland's case ,so he stated simply :Dr. John A. Wheeler estimates that a black hole of mass 10^9 kilograms might be generated artificially by the controlled thermonuclear fusion implosion of approximately 5 x 10^15 kg of deuterium."

Hansen stated that in USSR Teller -Ulam design was known,but this likely that among scientists,Novikov ,of course know this ( he was a Hawking's friend and Zeldovich (a Soviet Wheeler) protege) as Hawking himself.

Its most likely that this was a detailed simulation of such explosion.But mechanism would be more complicated than i'm believed .

10^9 kg-this is probably a uranium sphere in the centre of the bomb.

But what you could say about mechanism?


At 6:09 am, Anonymous Anonymous said...

Sorry,Im mean 5*10^16 kg of deuterium.

You are actually think that in the 1970-s it was impossible to simulate explosion of a such device ?

As ,for SUPER ,from Anne Fitzpatrick Teller’s Technical
nemeses: The American Hydrogen Bomb and Its Development within a Technological
Infrastructure” (TECHNE, Volume 3 No. 3, Society for Philosophy and Technology, Spring 1998),

"The idea for a thermonuclear weapon occurred in 1941 to physicist
Enrico Fermi one afternoon after lunching with Edward Teller in New York,
when the Italian physicist pondered aloud about whether or not an atomic weapon,
which was already in prospect, might be used as a trigger for a deuterium (D)
weapon. In principle, a bomb that fused hydrogen to helium was far more
economical and would produce a much greater explosion than a fission device.
Inspired by Fermi's suggestion, Teller took up the cause of exploring a fusion
weapon (see Rhodes, 1986, and Rhodes, 1995).
Igniting deuterium alone would require temperatures of hundreds of
millions of degrees, so Teller's colleague Emil Konopinski suggested that tritium
(H3) be added to the mixture to lower the ignition temperature. These ideas
became the basis of the "Super" weapon—a fusion bomb that in principle would
create an explosion on the order of megatons.The idea was exceedingly difficult to understand. During the war Teller
and his group attempted to work out the Super theory analytically (by hand), only
to find out it was more complex than anyone, even Teller, had originally
imagined. One major obstacle to the Super appeared in the form of energy
dissipation. The incredible speed of all the reactions inside the deuterium would
make it difficult to deliver the energy needed to reach the ignition point in a short
time. Furthermore, the Inverse Compton Effect would cause cooling of the
hydrogen electrons by collisions with photons coming from the fission initiator."


At 6:10 am, Anonymous Anonymous said...

Part.2. "Hydrogen bomb calculations involve charged particles in addition to
neutrons. Ignition of the Super required heating the material to a critical
temperature rather than assembly of a critical mass (see Metropolis and Nelson,
1982, p. 355). Thus, calculating whether or not the Super could be ignited was a
high hurdle; so was calculating whether or not a cylinder of deuterium, if
ignitable, would be self-propagating and burn. These two aspects constituted what
came to be known at Los Alamos as the "Super Problem."
How could the Super problem be calculated? Enter mathematician John
von Neumann, who had worked at Los Alamos during the war, and was not only
aware of but intrigued by the prospect of a fusion weapon. Von Neumann
arranged to have the Super problem run on ENIAC.
PHIL & TECH 3:3 Spring 1998 Fitzpatrick, Teller's Technical Nemeses/13
Only the first part (ignition) of the Super problem was run on the ENIAC
in 1945 and 1946. The entire calculation was meant to predict the behavior of
deuterium-tritium systems corresponding to various initial temperature
distributions and tritium concentrations. Collectively, the calculations attempted to
predict whether or not a self-sustaining nuclear reaction would occur and ignite a
cylinder of pure deuterium.
The calculations were only one-dimensional. Because of the ENIAC's
memory limits, several effects had to be left out of the problem. Though the Los
Alamos problem was the most complicated of its time, even using 95 percent of
the ENIAC’s control capacity, it did not truly answer the question of whether or
not a Super could be ignited, much less propagate (see Harlow and Metropolis,
1983). Mathematician Stanislaw Ulam once gave his opinion on this calculation:
The magnitude of the problem was staggering. In addition to all
the problems of fission . . . neutronics, thermodynamics,
hydrodynamics, new ones appeared vitally in the thermonuclear
problems: the behavior of more materials, the question of time
scales and interplay of all the geometrical and physical factors. . .
. It was apparent that numerical work had to be undertaken on a
vast scale (quoted in Aspray, 1990, p. 47).
The difficulty of the problem exceeded the technology of the time. Even
Teller, optimistic about the Super's feasibility, realized this and acknowledged
ENIAC’s limitations. Teller recommended that attention be paid to developments
in high-speed electronic calculators; thermonuclear calculations so far indicated
that the complexity of the problems required at least an instrument like the
ENIAC. In 1946, however, there simply were no other large machines available
to Los Alamos besides the ENIAC. The Super problem would have to wait.
Far from Los Alamos, construction of large computers was underway—
slowly, and most would not be ready for several years. Since other new
computers did not seem to be available quickly enough, the Los Alamos
laboratory did not want to wait and began work building its own electronic digital
computer. It was intended to be an exact copy of one that von Neumann was
building at the Institute for Advanced Study (IAS) in Princeton."


At 6:14 am, Anonymous Anonymous said...

"Teller and his colleagues had hoped that either the IAS computer or the
Los Alamos equivalent would be able to carry out a full simulation of the Super
by 1949 or 1950, but construction on both computers fell way behind schedule.
Growing impatient for any electronic machine to be ready, Ulam and University
of Wisconsin mathematician C. J. Everett attempted to solve the ignition part of
the Super problem with slide rules and hand computers, doing simplified
calculations; still, they were not certain if the device would ignite or not, even
though their results looked negative. (See Mark, 1974, and Ulam, 1976.) This
was a problem, then, that weapons scientists felt could not be solved with any
certainty analytically—at least in a reasonable amount of time. Von Neumann
once estimated that completing a hand computation of the Super problem would
require 100 hand computers and 4 years time.
Teller wrote to von Neumann in May, 1950, lamenting that the laboratory
was in a "state of phenomenal ignorance" about the Super. At this time there was
still no machine calculation which had unquestionably proven nor disproven the
feasibility of the Super, and Teller believed that this ignorance was due to the lack
of fast computers. (Personal accounts of some of these difficulties can be seen in
Bethe, 1982, and Los Alamos Historical Society, 1996.)
Teller was disillusioned and depressed by the end of 1950 because his
Super weapon was still not proven either to be workable or not. Moreover, Teller
and his colleagues were under more significant political pressure to at least test a
hydrogen weapon now that the Soviet Union had demonstrated its attainment of an
atomic weapon. At Los Alamos, Ulam produced the first breakthrough to a
workable but very different thermonuclear bomb, which he presented to Teller in
January 1951. Subsequently, Teller and a young protégé, Frederic DeHoffman,
produced a second crucial part of the new thermonuclear configuration. Teller
named this device the "Sausage"—perhaps ironically, as an easier device to
calculate than the Super configuration (see Hewlett and Duncan, 1972).
Collectively, the ideas of Ulam, Teller, and DeHoffman comprised a new
thermonuclear system that appeared viable on paper. It is also more commonly
known as the Teller-Ulam configuration. But even the Sausage would have to be
calculated and tested.
To expedite calculations and to help Los Alamos overcome its shortage of
theoretical help, Teller's friend and colleague, John Archibald Wheeler, had set
PHIL & TECH 3:3 Spring 1998 Fitzpatrick, Teller's Technical Nemeses/15
up his own group at Princeton University to calculate part of the new
thermonuclear configuration, since the laboratory needed as many available
electronic machines as it could get. Wheeler's secret project was code-named
"Matterhorn-B" (B for bomb), and that is where Sausage calculations were done,
and two-dimensional hydrodynamic problems began to indicate the feasibility of
the burning of deuterium in the Sausage.
In the spring of 1952, the Los Alamos computer—the MANIAC
(Mathematical and Numeric Integrator and Calculator; "Gamow" was its
alternative name)—was completed, and it too was instead used for cylindrical
radiation implosion calculations for the Sausage. These hinted at success for the
upcoming Ivy Mike test in November, 1952, which yielded proof of Teller's
fantasy of a multimegaton explosion.
By choosing to develop the radiation implosion Teller-Ulam
configuration, nuclear weapons scientists bypassed the Super problem. The
Teller-Ulam configuration, although itself a difficult model to calculate, was
easier to compute than the Super, a full calculation of which was not done on a
computer until the late 1960s on the Control Data Corporation's 6600 computers."


At 6:15 am, Anonymous Anonymous said...

So,she have seen a technical reports of the Wood and others on the SUPER.


At 10:01 am, Anonymous Anonymous said...

device ,tested in the Poplar was a w-41 warhead for a NAVAHO,not Mk-41.It was aimed at 9,000 pounds with a nominal yield -20mt.


At 9:24 pm, Anonymous Mabus. said...

The most important Part.3. has been missed due the worldpress


In the spring of 1952, the Los Alamos computer—the MANIAC
(Mathematical and Numeric Integrator and Calculator; "Gamow" was its
alternative name)—was completed, and it too was instead used for cylindrical
radiation implosion calculations for the Sausage. These hinted at success for the
upcoming Ivy Mike test in November, 1952, which yielded proof of Teller's
fantasy of a multimegaton explosion.
By choosing to develop the radiation implosion Teller-Ulam
configuration, nuclear weapons scientists bypassed the Super problem. The
Teller-Ulam configuration, although itself a difficult model to calculate, was
easier to compute than the Super, a full calculation of which was not done on a
computer until the late 1960s on the Control Data Corporation's 6600 computers.
Furthermore, the Teller-Ulam configuration also coincided with what Los Alamos
Theoretical Division leader T. Carson Mark called the “log-jam” in computing.
Weapons scientists were bound by the limits of technology and thus had to adjust
their research program under political pressure—with the limits of the
technological infrastructure in mind."

Original reports were :

1.LA-525 ,S. Frankel, N. Metropolis, A. Turkevich, Ignition of Deuterium-Tritium Mixtures : Numerical Calculations Using the ENIAC, March 2,1950,2, LASL.23p.-a sanitized version of this report has been released. Prima Facie Proof of the Super, April 15, 1946, LASL.58p.
Sanitized version avaible. C.J. Everett, S. Ulam,
Ignition of a Large Mass of Deuterium by a Burning Deuterium-Tritium Mixture: Problem I,
March 7, 1950, LASL.40p.Probably same situation.

4. la-1124. J. Everett, S. Ulam, ignition of a Large Mass of Deterium by a burning D-T
Mixture: Problem II, June 16, 1950, LASL.22p.

5.LA-1158,Considerations on thermonuclear reactions,36p.Ulam and Everett.

6. LA-1233,John Calkin, Cerda Evans, Foster Evans, John von Neumann, Klari von Neumann,
The Burning of D-T Mixtures in a Spherical Geometry, April 23, 1951, LASL.176p.

Wood and etc. reports unavailable,but i'm believe, that in the not so distant future they could be a subject for FOIA.

At 9:29 pm, Anonymous mabus said...

During ,a copyright program changed a letter "y" on the letter "V" please ,if you are accepet this comment correct this.


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