EDIT: I was absolutely missing a few things: the rod was uranium, not steel, and rings could be removed from the assemby.

Using the dimensions provided by Carey Sublette, and taking into account both the steel "can" of uranium, I arrived at the following masses:

Projectile: 42.06kg (62.15% of the total mass)

Insert: 25.61kg (37.85% of the total mass)

Total: 67.67kg

which is a hair over the oft-quoted 64.15kg. Is there something I'm missing? I'm not above making a schoolboy error or three. Unfortunately I don't have my copy of Atom Bombs immediately to hand so I can't compare Coster-Mullen's dimensions with NWFAQ at the moment.

It seems that HMX is very very slightly more dense than TNAZ however, the most dense form of TNAZ from what I saw appears to be about 400 m/s faster than the top velocity of HMX. Also, though HMX appears to be more stable, they both seem quite stable inside of a protective steel shell, so there isn’t much difference there. Last of all, HMX from what I read has 3 GPa more of blast pressure than TNAZ’s 36.4 GPa. Would it be fair to say that TNAZ makes a good substitute?

Glasstone and Dolan contains an extensive treatment of the development of the fireball in an airburst, but is very light on its development in underwater or underground bursts, besides mentioning that unless it breaks through the surface, the thermal emission is essentially totally absorbed by the surrounding media.

Some things I can derive myself from my knowledge of physics: The rate at which the isothermal sphere grows, and its ultimate radius, will likely be on order of a factor of 10 smaller than in an airburst, as water or soil are on an order of a factor of 1000 denser than air. In fact, in an underground burst that may be an even larger factor, as rocks and soil are composed of higher-Z elements than air or water that should take more energy to heat to the point of soft x-ray transparency.

But do you people know about any concrete numbers or equations that have been published?

Key Points

• France fired its M51.3 nuclear-capable ballistic missile from the submarine Le Vigilant for the first time on Oct. 6, without a warhead.
• The test certified Le Vigilant to carry the M51 after a major overhaul, and President Emmanuel Macron watched from the frigate Auvergne.

"France test-fired its newest submarine-launched nuclear missile, the M51.3, from a ballistic missile submarine for the first time on Oct. 6, with President Emmanuel Macron watching from a French Navy frigate off the coast of Brittany. ... The launch had a practical purpose. Le Vigilant recently completed a long maintenance and modernization overhaul, and the test certified that the submarine can once again carry and fire the M51, the ministry said. French ballistic missile submarines go through a similar firing after each major refit; Le Terrible did so in April 2023. ... France does not disclose its range, but public estimates for the M51 family generally put it at around 9,000 km (5,600 miles) or more, and French officials have said the new version flies farther. ... The missile’s first flight test took place in November 2023, when the DGA fired an unarmed M51.3 from its land-based Biscarrosse test site in southwestern France. The M51.3 entered operational service in October 2025. ... Macron said ... France’s next-generation ballistic missile submarines are under construction and that a program for hypersonic, maneuvering strategic missiles for the airborne leg of the deterrent was launched this year."

Generally it is estimated that Iran, with its current stockpile of 60% enriched uranium, could build around 10 nuclear warheads. First, what would be the estimated yield of such weapons? I've seen 10kt mentioned a couple of times, but not enough to be confident in it. Second, would it be possible for Iran to decrease the yield of weapons in order to have more of them? Say go from 10 warheads at 10kt to 25 at 2kt? Is there any document on the subject?

I'm curious to hear what some of your favorite nuclear and/or thermonuclear tests are? Which test is a favorite of yours and why? Theres no right answer, only personal preference. Feel free to include whatever tests you may like, small/big, doesn't matter. Try to limit it to surface and air blasts. Altho if you have an awesome underground one, feel free to tell.

Basically any test that you maybe just like the looks of or find intriguing, or feel a connection to because of its history, significance etc.

Here's some of mine;

Atomic bombs;

My all time favorite atomic bomb test must be "Ivy King", with an impressive yield of 500 kilotons, and often considered the largest pure fission test at its time in 1952. In other words a non boosted fission bomb, without any fusion fuel to boost yield. I enjoy its "classic" mushroom cloud, more than the actual yield. I also like the trinity test at 24kt (Often cited wrong at only 21kt until 2022 when los alamos upgraded it to 24 kilotons). It's just iconic and the footage is one that practically everyone has seen.

I also find the british test, "Orange Herald" very fascinating, as it was the largest atomic bomb test to attempt fusion-boosted fission, with a yield of 720kt. The fusion boosting component failed tho so it couldve had a much larger yield if it actually worked according to plan. As the fusion boosting failed, it therefor beats "Ivy King" as the bigger pure fission atomic bomb. Altho its debatable as it did attempt boosted fission. In any case it was so close to achieving megaton level yields, that it was actually mistaken as a H-bomb by the US back in 1957! Overall it was considered a failure for the british and a massive waste of nuclear material (117kgs of uranium-235).

Hydrogen bombs:

I have always loved "the super" aka Hydrogen bomb "Ivy Mike". I consider it the most stunning tests of all. The enormous fireball look incredible and terrifying at the same time. The size of the fireball grows immensely fast, expanding for miles while simultaneous nuclear explosion induced lightning (NEIL) in all sorts of brilliant colors. I think it's one of the most badass H-bombs. With a total yield of 10.4 megatons as surface blast, it wiped out the whole island it was built and detonated on. It was so powerful it terrified the people who witnessed it on ships. According to some navy personell who witnessed it from their ship, it was the most spectacular thing to see, yet it got frightening real fast as they felt the heat just get warmer and warmer and it never seemed to stop. Most took cover and went under deck after a short while because it got that unbearable. When the blast wave reached them it knocked most of them off their feet as well. I dont remember how many miles out the ship was.

Another H-bomb test I like is the Soviet Unions "RDS-37/Joe-19", which was their first two-stage Thermonuclear device after their "layer cake" design. Rds-37 had a yield of 1.6mt (scaled down from 3mt). It killed a few ppl and injured a dozen more in the nearest town. Not by radiation fallout but by the actual blast wave, which shouldve been prevented. The actual test looked great on camera and just always been a fan of it as you can see it's shape develop very well. Just an awesome sight.

The photos attached include; "Ivy Mike" before & after pics of the island it wiped out. And "Ivy King", Then "RDS-37S/Joe-19", and "Orange Herald".

Note: Goes without saying that I am not glorifying anything. I know how awful and destructive these things are. Just fascinated by it and interested in all the science behind and judging them solely as science experiments/tests. I am fully aware, as I hope everyone is, of how utterly terrifying and destructive nuclear weapons can be. It's therefor important to separate tests from when actually used in war against ppl.

Also I apologize in advance if this is "TLDR" lol!

For the first time in history, go inside the nuclear deterrence mission like never before. Premiering on select IMAX screens and streaming this November, THE WATCH: America’s Nuclear Mission offers extraordinary access to the most important global security mission in history. Meet the men and women who have kept the world safe from nuclear conflict since 1945. No CGI. No AI. Ever.

I found it among photos I had saved from the web—basically while digging through the "dump" folders on my hard drive. The file creation date is December 2019. On the left is an enlarged, enhanced, and slightly colorized version of the black-and-white original shown on the right (which was a very small image). I ran a Google image search but found no matches (even though I obviously got it from somewhere online, possibly a Russian forum dedicated to nuclear weapons). AI initially identified it as the "Gemini" module for the Titan II, and then—after I enhanced and colorized the image—as the XMGM-134A Midgetman (though I checked, and the size is completely wrong for that).

What really floored me about this photo just now? It turns out I didn't just save this blurry image back then (I don't recall when or how); I actually labeled it: "Mk.6 warhead section for the Titan II missile, with a yield of 10 to 15 Mt." Wow! I have absolutely no memory of where or when I got it or why I labeled it that way! It might have been before I knew for a fact that the Titan II never carried anything more powerful than the 9 Mt W-53 warhead. I likely didn't connect the photo at the time to McNamara's 1962 statement about a super-powerful 30 Mt warhead for the Titan II—a connection people make now in light of plans to develop RIPPLE technology (articles on RIPPLE only started appearing in 2020). Otherwise, I would have remembered it! The photo does indeed look like an Mk.6-type warhead, but it’s clearly larger (or so it seems to me). So, what is it? Could it be what I suspect—work related to RIPPLR? Though that seems highly unlikely. Still, I decided to share it here and ask, just in case.

No new information, but a classic old British COI film. Hurricane was quite a feat in conducting what combined a very comprehensive effects test with the first proof of a UK plutonium implosion device in a remote and difficult location.

"he U.S. government set off conventional explosives inside a tunnel deep in the Nevada desert this week in a test designed to replicate a so-called “decoupled” nuclear detonation. Data collected is now being used to help improve methods for detecting this kind of nuclear testing. Just earlier this year, American authorities accused China of using decoupling to conceal new nuclear tests despite the country’s stated moratorium on such activities.

The test, which involved the use of chemical high-explosives and radiotracers, was conducted yesterday inside P Tunnel in Area 12 of the Nevada National Security Site (NNSA), according to a press release from the National Nuclear Security Administration (NNSA)"

I've been updating the shaders in my browser-based Blastmap project. This comparison shows 15, 100, 1,200, and 15,000 kt from the same viewpoint over NYC, all at a 550 m burst height.

The focus is the evolving fireball, Wilson condensation cloud, lighting, and ground dust. The clips run in increasing yield order and retain their original playback speed; the larger yields have longer clips to show more of the cloud development.

It's a work-in-progress visualization, with NYC serving as a common scale reference. Feedback on the cloud behavior and rendering is welcome.

New here so sorry for my lack of technical understanding. I’ve heard that tsar bomba was a three stage design but often it is portrayed as 2 fission primaries and a fusion secondary.

As to my understanding this portrayal is not a true 3 stage design as that would be fission>fusion>fusion not two fissions for one big fusion.

Also if it did use two primaries and was three stage would it be two thermonuclear devices with a third fusion stage between the two? As far as I know X-ray implosion can be done with a fusion or fission reaction. So was the two primaries a function of making the device more “bomb” shaped instead of a triangle or something else.

Using just one primary and having the secondary light the tertiary seems far more reasonable to me then trying to perfectly sync two primaries (also I’m sure there was some variance in the yield of the two primaries) to converge in the center even more so if it was two primaries and secondaries.

Keep in mind I’m a layman with an AA degree when I know this is a PHD topic so forgive me. Im sure my description of a three stage device’s physics package as a “triangle” is going to make some people cringe just is the simplest way in my head it’d look like.

As the titel suggested! Do you think it would even be possible?

Watched the whole thing, she goes into some detail on the WWII German nuclear program, quite a bit of stuff I haven’t heard of or read before.

Interesting article on the last German reactor during WWII and if it could produce fissile material for a bomb.

(https://academic.oup.com/pnasnexus/article/5/9/pgag282/8836799?login=false)