The figure shows three maps of three powerful city center explosions, resized to be on the same scale. On the left is the Nagasaki nuclear explosion, on the right is the Hiroshima nuclear explosion (both 10-kiloton). In the center is the 2020 explosion of 3,000 tons of ammonium nitrate in the port of Beirut, with a blast equivalent to 1 kiloton.

Looking at the Beirut explosion chronicle and the image I received, one gets the strong impression that all three explosions are remarkably similar in their blast effect. Yes, we understand that the destruction radius for 1 kt and 10 kt of the same nature will differ by only a factor of (10/1)^(1/3) = 2.15 (the inverse-cube law for any explosion on the bottom of the air ocean). Nevertheless, the feeling remains that an equivalent nuclear explosion is clearly weaker in destructive power than a conventional chemical explosive. In fact, this is noted in many sources. And there's no particular mystery here. This is due precisely to the fact that, with equal explosive energy, the momentum, or destructive impulse, of a chemical explosion is clearly greater due to the greater mass of the substance involved. An explosion with a 3-ton chemical explosive yield will rupture any explosion chamber, but for equivalent 3-ton peaceful mini-thermonuclear explosions, explosion chambers of a quite reasonable size are designed.

Let's do some quick math. The port of Beirut contained 2,750 tons of compacted ammonium nitrate, which exploded with a yield of 1.5 kilotons. The density of ammonium nitrate is 1.72 tons/m³. Therefore, the entire mass that exploded there can be represented as a solid ball of fertilizer with a diameter of 14.5 meters.

In a chemical explosion, 90% of the explosive energy is converted into the kinetic energy of gas expansion (which creates a shock wave in the atmosphere). Therefore, we can calculate the notional total, initial velocity of the explosive ammonium nitrate "piston" using the law of conservation of energy as follows: (2 * 1.5 * 4.18E + 12 * 0.9/ 2750,000) ^ (1/2) = 2026 m/s. Assuming that the entire mass of gases at the moment of explosion acquired this velocity, the momentum of the explosion is the product of the mass of the explosive and the velocity: 2,026 x 2,750,000 = 5.57E + 9 kg m/s, which ultimately translates into the motion of the crushing shock wave.

What about a similar nuclear explosion of 1.5 kt? Such an explosion essentially occurs in a pinpoint device, say, 200 kg in mass. A momentary flash of energy and X-ray radiation occurs, which is intensely absorbed in the air around the explosive device, turning the area into a fireball, and it is in this fireball that the shock wave is generated. The empirical formula for the shock wave's separation radius from the fireball (at the ground's surface) states the following:

R = 47*q^0,324

Here, q is the explosive yield in megatons, and therefore the shock wave's separation radius for a 1.5 kt air explosion is 6.52 m. This means that the diameter of the sphere from which the shock wave is generated is 13 m. The air contained in this sphere essentially acts as the piston that creates the shock wave of a nuclear explosion. With a density of 1.25 kg/m³, we obtain that the mass of the nuclear explosion "piston" (plus the mass of the charge itself) is 1.622 tons. Moreover, based on the fact that only 45% of the explosion energy is converted into shock wave motion (the rest is various types of radiation), from the law of conservation of energy, as in the previous case, we calculate the average speed of the air "piston": (2 * 1.5 * 4.18E + 12 * 0.45/1622) ^ (1/2) ~ 59,000 m/s. Hence, the total momentum (mechanical impulse) generated in the fireball of a nuclear explosion: 59,000 * 1.622 = 8.4E + 7 kg * m/s.

This momentum is 58 times less than that of a chemical explosion of saltpeter of the same energy equivalent.

Of course, my calculation is a rough, "on the napkin" estimate. Nevertheless, the fact that a nuclear airburst was clearly inferior in its destructive effect on the buildings of Hiroshima to conventional explosives was noted back in 1947 by Sir P.M.S. Blackett in his book "Fear, War and the Bomb: Military and Political Consequences of Atomic Energy." A more thorough and dispassionate analysis (the British had good statistics on the effects of conventional bombing on cities) showed that the destruction wrought by the "Little Boy" bomb in Hiroshima, using conventional chemical explosives, could have been achieved using just 2,000 one-ton high-explosive bombs (of which only one-third the mass is explosive) dropped from conventional bombers. Since the yield of the Hiroshima explosion was then officially declared to be 20 kilotons, Mr. Blackett "discovered" a "missing" order of magnitude in the destructive effectiveness of the new American weapons compared to the old ones. Of course, part of the deficiency can be attributed to the fact that a single explosion causes excessive destruction at the epicenter, while the effect drops off sharply with distance to the periphery. However, this is only part of the "missing" factor. The Beirut explosion was also a single-point explosion, and with 10 times less energy, it produced destruction comparable to the atomic bombings. The second factor is that a nuclear explosion is a pulsed release of enormous energy, which is not immediately converted (as in a chemical explosion) into the movement of matter, into a direct high-explosive shock wave impulse. The flash of light must first be absorbed by the air in the fireball, which becomes a "piston" for the shock wave, and due to the low density of air, it is a very poor "piston." Moreover, as the explosive yield increases from the nominal 20 kt (to 200, 2000 kt), the situation with the mechanical efficiency of using the explosive energy to destroy objects around it only worsens. This means that nuclear weapons, especially high-yield ones, are very ineffective weapons of destruction from a physics perspective. One suspects that this is precisely why the "paper" city of Hirashima was chosen for the demonstrative destruction of people and buildings, and its population, like ducks, was long trained not to react to the appearance of a pair of American planes in the air. The goal was to achieve a demonstratively exaggerated effect from the new weapon, one that could never be replicated. The severed head of Medusa can only work once.

Therefore, all this frightening talk about terrifying nuclear megatons hanging over the world like the Sword of Damocles, the eternal appeal to Hiroshima as a model for calculating casualties and destruction (Nagasaki, for example, is used much less frequently and only in passing, because the effect there was much more realistic) is blatant manipulation, essentially a pure lie. The military knows the truth. It was the actual, physical effectiveness of nuclear weapons, after being studied, that caused great disappointment. That's why recently there's even been talk about high-precision weapons being able to replace nuclear weapons! For real warfare, that's (almost) true. But why "disappoint" a flock of self-terrified civilians with this? They (especially the humanist physicists) so desperately wanted to invent a doomsday weapon and thus end wars on Earth once and for all! It so flatters their vanity and their humanist pride!

Like a decade ago I read that this subs missile hatches are forced-open and its warheads missing. Though the hatches could have been blown by the implosion forces, warheads should be littered all over the wreck-site. Does anybody have actual info about it, what actually happened or its current status? Did Russia go in there to retrieve them? Like Scorpion's wreckage, seems like a somewhat easy way to get a nuclear weapon provided you are a resourceful country.

In the 2010 book "РЕШАЮЩИЙ ШАГ К МИРУ ВОДОРОДНАЯ БОМБА С АТОМНЫМ ОБЖАТИЕМ РДС-37" (A DECISIVE STEP TOWARDS PEACE: THE RDS-37 ATOMIC-COMPRESSIONED HYDROGEN BOMB), among numerous excerpts from declassified documents, I came across a document that, in my opinion, has sensational content. Below I'll provide a direct link to the relevant page in this book, available from the Rosatom library, but since links to the .ru domain are unacceptable here, it's replaced with asterisks:

https://elib.biblioatom.**/text/andryushin_reshayuschiy-shag-k-miru_2010/p63/

First, I quote in Russian:

Записка В. И. Ритуса

"О некоторых возможность применения малого термоядерного заряда.

Для атомного обжатия большого количества легкого вещества, по-видимому, целесообразно использовать в качестве обжимающего изделия систем из обычного изделия и маленького термоядерного заряда, так что вся система в целом будет выглядеть, как на рис. 11. < ... >

После взрыва "1" происходит AO термоядерных зарядов "2" и "3".< ... >

Такое растущее со временем давление приводит, как известно, к значительно лучшему обжатию изделия "3", чем давление, спадающее со временем.

Ниже приводятся некоторые расчёты обжатия и КПД конкретного малого термоядерного заряда."

Следует подчеркнуть, что в 1955 г., кроме разработки РДС-37, велась масштабная работа по другим направления. План работ на 1955 г. определял разработку 5 ядерных зарядов, 8 ядерных боеприпасов.

* * *

Now the English translation:

Note by V. I. Ritus

"On some possibilities of using a small thermonuclear charge.

For the atomic compression of a large amount of light matter, it is apparently advisable to use a system consisting of a conventional charge and a small thermonuclear charge as the compression element, so that the entire system will look like Fig. 11. < ... >

After explosion "1," AO of thermonuclear charges "2" and "3" occurs. < ... >

Such increasing pressure over time, as is known, leads to significantly Better compression of the "3" product than pressure decaying over time.

Below are some calculations of the compression and efficiency of a specific small thermonuclear charge."

It should be emphasized that in 1955, in addition to the development of the RDS-37, extensive work was underway in other areas. The work plan for 1955 called for the development of five nuclear charges and eight nuclear weapons.

* * *

Of course, Figure 11 from Ritus's report is missing from the book, but it doesn't take a rocket scientist to reconstruct it with 80% certainty. I've done so on the left in the collage attached in the title.

The topmost Figure A shows the structure of the device in its original state. Within a single radiation enclosure (the hohlraum), separated by membrane partitions and neutron filters (the purpose of which is to prevent neutrons and direct rays from propagating from stage to stage), are the primary unit 1 and two secondary units: the small thermonuclear unit 2 and the large thermonuclear unit 3.

In Figure B, we see the detonation of the primary unit. The hohlraum is filled with X-rays, which causes the simultaneous compression of both thermonuclear units, the small 2 and the large 3. This is shown by the transparent red arrows.

Figure C shows that, because small fusion node 2 is smaller, it fires earlier and now, instead of being an energy consumer in the hohlraum, becomes a new, more powerful X-ray source than the primary node. Thus, the still-contracting second, larger fusion node 3 begins to contract even more, as indicated by the solid red arrows.

Figure D shows that large secondary fusion node 3 has now also exploded.

The phrasing in the original 1955 source is striking: "Such increasing pressure over time, as is known, leads to significantly better compression of the '3' product than pressure decaying over time." I mean "as is known." From the very beginning of their atomic compression research, the Russians were well aware that compression with a single shock wave was ineffective, and this solution was proposed precisely to increase compression efficiency, that is, to approximate the compression cvazi-adiabatic with two shock waves. In 1966, Zeldovich's famous book was published, clearly demonstrating and stating that three such correctly sent shock waves, one after the other, are sufficient to approximate adiabatic compression with the required degree of accuracy. I've included the relevant figure from Zeldovich's textbook in the collage, although it's already well known here.

And finally, why did the Russians so easily declassify and publish a description of this idea? Because, while fundamentally correct, it was subsequently deemed a dead end, not the best solution (it's worth revealing). A far better solution to this same problem was quickly discovered, and we see it in 1962, in the no less famous "Golden TIS" (I also include it in the collage), in which the USSR first achieved ignition of a thermonuclear stage without a spark plug. Note the three-layer outer shell made of low-, medium-, and high-Z materials. This is essentially a three-stage ablative "rocket" that sequentially creates three compression shock waves with a constant radiation source in the hohlraum. That is, unlike RIPPLE technology and Ritus' proposal, they did not control (stepwise increase) the temperature in the hohlraum using any intermediate devices. They simply deposited three layers of different Z values ​​on the secondary module. As a result, the same radiation from a single primary, with an equilibrium temperature of hohlraumet T (it's even stated to be ~1 keV), created three pressure steps:

P(i, T) =N(i, T)kT = N[Z(i),T]kT ; i =1,2,3

Therefore, for us, reconstructors of early Soviet thermonuclear bomb designs, an additional problem arises. When did the Russians begin using this more complex compression? Starting with which devices? Before Khrushchev's moratorium or after? I'm inclined to think that after the moratorium, simply because they had so many more pressing problems before the moratorium, that even with every opportunity to test the idea, they put it aside and probably thought it through thoroughly during the testing break. And then the question arises: was this multilayer compression already used in the AN-602 design, in "Kuzkina Mama"? If so, this would completely resolve the confusion surrounding how this device could have achieved 50% burnup in the final stage. Let me remind you of the crux of the matter. The dimensions of the "Главный Кенр" "main core" (jokingly nicknamed "The Death of Capitalism" back in RDS-37), a 1.7-meter-diameter sphere, when completely filled with lithium deuteride at its normal density (820 kg/m³), simply do not allow for a lower burnup percentage (given the Lidochka's calorific value of 50 kt/kg). If we don't accept the 50% burnup as fact (reducing it to the usual 25-30%), we would have to invent absolutely insane designs for this device with two or more "main components," which would completely contradict everything we've pieced together from countless Russian memoirs.

Launch Under Attack: A Sword of Damocles

Carried inside the two-component pod under B-58A Hustler. Yield in the megaton range. Photo from USAF museum in Dayton, OH.

Typo on the title. Should be Tinian.

The “Little Boy” atomic bomb in its pit on Tinian and being loaded into the bomb bay of B-29 “Enola Gay” - August 5, 1945

The fission reaction was accomplished by shooting a hollow cylinder (the "bullet") onto a solid cylinder of the same material (the "target") by means of a propellant charge. Little Boy contained 64 kilograms of highly enriched uranium.

Courtesy of World War Pictures on Facebook
NARA / US Navy / USAAF

NARA

2. The “Little Boy” atomic bomb being loaded into the bomb bay of B-29 “Enola Gay” at Tinian - August 5, 1945

NARA

3. The “Little Boy” atomic bomb is fit checked after being loaded into the bomb bay of B-29 “Enola Gay” at Tinian - August 5, 1945

NARA

A number of people dancing to this during the big '80s never noticed the lyrics?

https://youtu.be/-vMBp6iUJzk?si=uEOSvG-mDIwvoGhb

In the book "The Decisive Step Toward Peace" by Andryushin et al. (one might say the most official account of the creation of the RDS-37), published in Russia in 2010 and literally peppered with excerpts from documents, I found this seemingly unrelated, modest group photo of children. But these seemingly ordinary children, staring sternly into the photographer's lens—Pioneer Leninists, middle-school students with their teacher in the center—are not so ordinary. Their parents worked as testers at the Semipalatinsk nuclear test site, and the children lived and studied alongside them. The photograph was taken in October 1955, at the height of the testing, a couple of days after the RDS-37 explosion. These children lived where the USSR detonated its very first atomic and thermonuclear bombs. They grew up next to the mushroom cloud on the horizon. And since the closed Soviet cities of Kurchatov and even Semipalatinsk received advance warning of the explosions, the children of the testers tried by any means necessary to sneak out of classes (they were often cancelled during this time) and find a vantage point to observe the explosion. In the more distant city of Semipalatinsk, they tried to climb onto the rooftops of buildings to get a better view of the distant explosion on the horizon. Of course, they were forbidden from doing this, the rooftops were closed, but they still managed to get there.

Why are most of them already dead? It's simple. Do the math. It's 2026 now, but back then it was 1955. 2026 minus 1955 is a difference of 71 years. The children in the photo are at least 8 or 9 years old. That is, by now they would all be 79-80 years old. And the average life expectancy in Russia, according to statistics, is 73 years. For men, it's lower, 65-68 years. So, statistically speaking, half of them are guaranteed to be dead. And most likely, much more than half. I didn't lie one iota in the title of this post!

Did you think I'd tell horror stories about radiation like so many who come here? Like hell! I grew up practically on a "nuclear wasteland"—Chernobyl is 400 km away—but even here, the area around me is nothing but granite and granite quarries, "full of radon" (granite is supposedly a very low-grade uranium ore). From infancy, we knew from our own experience that the blast wave from a quarry travels through the ground much earlier than the sound of an industrial explosion through the air. And as children, we were constantly wandering around abandoned and active quarries (and when I became a tourist, we were constantly hanging out in a still-operating quarry because it had the best sport climbing wall in the area). There's a legend in town: when a Japanese delegation of specialists first came to one of the nearby quarries in the 1970s as part of a contract for the supply of raw materials, carrying their own sensitive dosimeters, they never made it to the quarry. Their dosimeters started sounding the alarm as they approached, and they demanded the bus be returned to the hotel. How did we feel about this? We laughed (it wasn't until ten years later that "green activists" arrived from the West and began to twist our common sense like they have most of you). After laughing at the cowardly Japanese, we locals then said, as the unforgettable Vovochka said in the well-known joke (about a high school student called to the board to answer a question, having just learned that his deskmate had gotten pregnant), "I wish I had your problems, Marya Ivanovna!"

I wonder how many dislikes this message will get? Shall we find out?