I wonder if the bunker buster was used. It has a somewhat indirect lineage to the ww2 grand slam designed by Barnes Wallis.
Iran has massive earthquake risks. For reasons unassociated with nuclear bunkers they do a lot of research into (fibre, and other) strengthened cement construction. With obvious applications to their nuclear industry of course.
Another unrelated point, a significant number of Iranian civil engineering graduates are women. A somewhat dichotomous economy, when you consider the theocratic restrictions on costume and behaviour.
> Another unrelated point, a significant number of Iranian civil engineering graduates are women. A somewhat dichotomous economy, when you consider the theocratic restrictions on costume and behaviour.
Iran does not have the same degree of sexist restrictions as eg Saudi Arabia. It's a very different climate from places where salafism is more common. Female education in particular is highly supported eg: https://x.com/khamenei_ir/status/1869369086142296490
> Another unrelated point, a significant number of Iranian civil engineering graduates are women. A somewhat dichotomous economy, when you consider the theocratic restrictions on costume and behaviour.
I thought it was generally known that richer societies with me equal treatment - where people are generally more able to choose jobs they like rather than needing to take whatever's a ticket to a decent life - are the places with higher disparities in well-paying occupations?
I doubt that the intersection of IRGC volunteers and potential university students is too big.
The gender ratio is similar in other Middle Eastern countries. Once women in the Islamic world get the legal right to educate themselves, they tend to make use of it much more than men do. It is a pathway towards personal independence.
As I understand it enrichment is by gas centrifuge or thermal diffusion. An earthquake bomb would disrupt both. You wouldn't be starting the feed cycle up rapidly, but since we're told Iran has stockpiles, this goes to sustainable delivery of materials more than specific short term risk.
As a strategy, I see this as flawed. A dirty bomb remains viable with partially enriched materials.
(This does not mean to imply I support either bombing or production of weapons grade materiel. It's a comment to outcome, not wisdom)
> A dirty bomb remains viable with partially enriched materials.
A dirty bomb is basically Hollywood nonsense, and wouldn't use uranium to begin with because it isn't very radioactive.
The premise is that you put radioactive materials into a conventional explosive to spread it around. But spreading a kilogram of something over a small area is boring because you can fully vaporize a small area using conventional explosives, spreading a kilogram of something over a large area is useless because you'd be diluting it so much it wouldn't matter, and spreading several tons of something over a large area is back to "you could do more damage by just using several tons of far cheaper conventional explosives".
Also anything that is dangerous enough to actually be scary in dirty bomb form, like Cobalt-60, would be impossible to handle without providing a lethal dose of radiation to anyone working with he material within minutes if not seconds (presumably a reasonablely large & dangerous amount of this material is involved). At least, not without incredibly expensive equipment. And by the time you factor in those prerequisites it's just not worth it.
And has the same issue with dilution, and is even more boring because there are much cheaper things with more chemical toxicity than uranium too, like lead.
Uranium, especially highly enriched uranium, is not very radioactive. That's one of the reasons its useful for weapons. UF6 is chemically really nasty, but it's heavy and also you have criticality issues that limit how much you can pack into a confined space before it explosively disassembles. That is to say, it would make an extremely poor dirty bomb that would do very little. It'd scare people of course but there are far easier things they could use to achieve that.
Far more concerning is the possibility that they give it away to someone else. Enrichment is nonlinear, going from 60% to the 90% needed for weapons is a fairly trivial amount of work.
> It'd scare people of course but there are far easier things they could use to achieve that.
I wouldn't discount it, though. Remember, feelings matter more than facts. Magnitudes more people die on the road than in the air, but we know how well that translates to fear and action.
I mean heck, how about 9/11 compared to COVID? Wearing a mask for a while: heinous assault on freedom, Apple pie, and the American way. Meanwhile, the post-9/11 security and surveillance apparatus: totally justified to keep America safe
Yeah, my point is there are much better options that would also induce fear and actually be effective. Fentanyl strapped to an explosive, or any of a ton of other chemical agents. Iran would do far more damage -- and create a deep source of fear that would likely have lingering consequences for decades -- by giving their HEU away rather than making an ineffective dirty bomb. There is no way anybody who knows what they had would use it that way. Even the most fanatical member of the Iranian regime understands what to do with the material better than that.
While true, the problem is it wouldn't meaningfully change the security situation for Iran.
Deliverable nuclear weapons make you invasion proof - nobody wants to risk it. A "dirty bomb" isn't something that can come flying in on an ICBM and eliminate large chunks of your nation - the threat of it is more likely to enhance aggression rather then deter it.
I'd say the same could be said for 9/11, which didn't really achieve anything positive for anyone but did make for a large bit of "The US hurt itself in its confusion"
Can anyone explain the science behind this statement? To be clear: I believe it, and I have seen multiple reputable sources say that Iran can enrich to 90% within a few months. I was surprised that it is so quick.
You start with natural uranium, which has .72% U-235. Getting from that to 20% is _hard_. You need large cascades of centrifuges to do this because it's only .72%, so each stage gets you just a wee bit more enriched. You do this over and over and over again until you get to higher enrichment. Once you have HEU enriching further is very easy for the same reason that it was hard when it was unenriched: now the stuff you don't want (U-238) is much less. To get from 80% HEU to 96% is trivial using the same centrifuge cascades, and how long it takes really depends on a) how much 80% HEU you have, and b) how much 96% HEU you want. If you have 100lbs of 80% HEU then to get to 10lbs of 96% HEU might really only take weeks if not less when it might have taken years to get from .72% to 80%.
Yep, https://web.mit.edu/22.812j/www/enrichment.pdf is a good starting point if anybody wants to learn more about the economics/logistics of enrichment. Though, it's a notoriously confusing topic so it could take some reading.
Tl;dr is that the amount of energy required to separate a mixture of gasses (U238 waste and U235 product) is roughly proportional to the logarithm of the ratio of the U238 percentage and the U235 percentage. So as your feed stream becomes more enriched in U235, it becomes much easier to do subsequent separations. This log relationship is an approximation, but arises out of the statistical mechanics of separating two mixed gasses and the resulting decrease in entropy.
Edit: a key point most people I'm guessing aren't aware of: centrifuges don't really care what you feed them, whether the feed is natural or 20% or 89% enriched, they just get increasingly more efficient so that a single "pass" through them produces a greater amount of separation as the feed stock becomes more enriched. They do a fixed amount of "separative work" each pass. The same machines can be used to enrich from natural to 20% as 20%-90% (with some relatively minor caveats), and in fact it takes far fewer machines to do the 20-90 step at the same rate as natural-20.
You know how Shannon entropy works in CS, compression and stuff? Atoms work the same way: their mixing entropy is that same x*ln(x) sum which is an extremely steep function near its boundaries. That's your non-linearity. That statistical entropy corresponds to macroscopic thermodynamic properties, enthalpy and work. The starting uranium atom ratios, 0.7%/99.3%, are a very unbalanced mixture deep into that non-linearity side.
(The other half of it is that, as you progressively enrich, you start to discard the "depleted" part of the mass flow, and work only with the, gradually smaller, "enriched" mass flow).
China is estimated to have approximately 600 nuclear warheads. China is rapidly expanding and modernizing its nuclear arsenal and is projected to reach at least 1,000 operational warheads by 2030.
Israel is widely believed to possess around 90 nuclear warheads.
Israel never acknowledged that. It is claimed that the US president at the time demanded that Israel kept this a secret to avoid embarrassment to the US.
Iran repeatedly calls for death to Israel and the USA. Israel never did that.
they're saying in fewer words "watch what leaders say, not what they do"
iran might be saying a lot, but if it wanted war, it would have been attacking, the same way that israel is attacking gaza, not threatening gaza.
even now when iran has responded to israel's attacks, you still seem to care more about iran's threats than iran's missiles.
-----
on your very long aside, you are mislabelling the positive sum behaviour as zero-sum.
you might see the point in putting at least equal blame between israel and hamas for the conflict with the positive sum descriptor. israel is in a mutually beneficial escalation and continuation of violence with hamas. an extreme right wing populace in israel is a win both for hamas and for israel. neither care about the palestinians, nor the israelis.
> they're saying in fewer words "watch what leaders say, not what they do"
Didn't you reverse it? Didn't you mean to say what they do not what they say?
Iran conducted a terrorist network against Israel for decades. It's behind Lebanon, Syria etc. They also called for death to Israel and countless other examples. It's pretty clear what they want to do.
Would they use nuclear weapons against Israel?
No idea. Don't want to know. Just like I'm glad I don't know what Saddam or Assad would have done with their nuclear weapons (had Israel not bombed them away).
> even now when iran has responded to israel's attacks, you still seem to care more about iran's threats than iran's missiles.
Right now Iran doesn't have nuclear weapons. They were able to kill quite a few Israelis (thankfully not as much because the strikes took down a lot of their launchers/missile caches). I'm concerned about what they say because I know where they are headed if they do somehow gain the weapons to kill everyone.
When someone says they want to kill you and your family: believe them.
> on your very long aside, you are mislabelling the positive sum behaviour as zero-sum.
Nope. Death to Israel is very much zero-sum.
The reason for your confusion is that Iran didn't attack Israel directly and mostly through proxy. That doesn't mean they aren't trying to destroy Israel, they are just cautious about it. Their goal is still the same.
> you might see the point in putting at least equal blame between israel and hamas
Nope. Israel tried to have peace with the Palestinians. Hamas blew up that peace by blowing up busses and coffee shops in the middle of Tel Aviv until that collapsed. They are a zero-sum player who won't settle for peace.
Israel built defense systems and shelters for its people. It ignored Hamas built rockets launched constantly at its cities and tried to "let them be". But they miscalculated. They saw Israeli tolerance as a weakness and assumed Israel doesn't have the stomach for a painful war. They are 100% at fault here and brought about the whole thing.
The fact that this is Hamas's fault doesn't absolve Israel of the brutality of this war and some of the awful things it did. It's just context.
> israel is in a mutually beneficial escalation and continuation of violence with hamas.
It's pretty bad that you lump all of Israel together but make the distinction for Hamas. Hamas made a choice to open a can of worms when Israel had one of the worst governments in its history.
> an extreme right wing populace in israel is a win both for hamas and for israel. neither care about the palestinians, nor the israelis.
I mostly agree, but it will be far worse for the Palestinians. Israel will survive regardless of the outcome. Palestinians don't have that privilege. As such Hamas is far worse, it is a suicide cult.
So based on your logic we should just let them gain that ability and see what happens?
> It is similar to swearing at someone "Fuck you". It doesn't mean you're actually able and willing to.
Since they conducted decades of terrorism against Israel the USA and our allies a more apt example would be a person who repeatedly stabbed our friends is trying to get a bomb that could kill us all.
It's amazing to me how people are willing to give the benefit of the doubt to people who literally led terrorist attacks against their country. To people who would stone gay people and punish women for the crime of rape. But won't give a similar benefit of doubt to the people opposing them. Who won't consider that, maybe, just maybe, the stuff you read on the internet isn't the whole truth.
> Since they conducted decades of terrorism against Israel the USA and our allies a more apt example would be a person who repeatedly stabbed our friends is trying to get a bomb that could kill us all.
I'm going to play a childish game with you: who started it first?
> Who won't consider that, maybe, just maybe, the stuff you read on the internet isn't the whole truth.
Iran is prone to earthquakes, would an earthquake bomb do more damage than that?
Even if it just damages the centrifuges, as far as I see it, it would just delay their enrichment process, severely less than total destruction of their underground base.
Yes that's basically my point. They recalibrate, tighten the pipes, and flush the contamination back out of the chain. 6 to 8 weeks/days/whatever later it's back in cycle.
> As I understand it enrichment is by gas centrifuge or thermal diffusion.
Centrifuges. They got them via the A. Q. Khan network. We learned about if circa 2005 from Qaddaffi who gave up his to secure peace and his safety (and it didn't turn out well for him because Obama did not respect the gentleman's deal Qaddaffi had with Bush).
Whatever about bombing Iran with conventional weapons, being the first president since Truman to nuke another country would split Trumps support base, and also legitimize using nuclear weapons in regional conflicts which would be extremely bad news for Ukraine
The kinetics matter here. The B2 flies much higher than the C-130 which would aid the GBU-57 MOP (almost certainly used here) in it's ability to penetrate to maximum depth. 80% of the 15 ton weight of that bomb is just heavy metal to give it maximum energy as it borrows into the ground.
Also, each B2 can carry 2 MOPs making it a better platform than a C-130, and that isn't even taking the stealth of the platform into account
Don't think the C-130s can fly high enough with a single 30,000lb bomb. The graphic at bbc site show it would be dropped from about 12km (~40,000 ft) in order to gain the speed needed to drive it some 60m underground.
The MOP isn't particularly 'advanced', it's basically refined version of the Korean-vintage Tarzon guided earthquake bombs. It's just too heavy for most military aircraft to carry.
The IDF has the F-15I which has a centerline hard point rated for 5,000lb load. That's immense for a fighter but a magnitude too low for the MOP.
There are a variety of smaller US penetrating bombs that the F-15 can handle, but they don't have the mass and structure to penetrate as deeply.
According to Israel they fly freely in West/central Iran and use all the plains including F15/16. Initially they relied on the F-35's stealth but as of last week they claim air superiority.
You are correct but although the B52 can technically carry the GBU-57 MOP, but it was only done that way during the initial testing of the weapon. The B2 is the only aircraft the USAF actually uses for that munition in combat scenarios.
Also the B2 is better suited for extreme endurance missions like this where the plane is in flight for >36 hours. It has a toilet, microwave and a cot for the pilots to use during the more mundane parts of the mission.
they might be right, but that's why the attack failed and why there's a risk what I said might still come true
i was listening to Al Jazeera, one of the DC flaks they interviewed gave an upper estimate of the facility depth as 1000 ft. The conventional device can go to something like 60m or 200 ft. 6 devices were dropped, they would have to have everything, including geology with repeated strikes on the same point, be perfect to get past 1000 feet, and then they probably would not destroy the whole facility. As far as I know, they don't even have a good map of the layout.
hence, the only real option is a nuclear weapon. this is absolutely being considered inside the pentagon. our government is psychotic. a 1 kt nuclear weapon (laughably small, hiroshima was 15 kt) is 73x more powerful than a 30,000 lb bomb. they would be like, well, it's an underground explosion! The world will forgive us. it's so crafty and smart to use a nuke to stop a nuke (that doesn't exist).
"The effectiveness of GBU-57s has been a topic of deep contention at the Pentagon since the start of Trump’s term, according to two defense officials who were briefed that perhaps only a tactical nuclear weapon could be capable of destroying Fordow because of how deeply it is located."
Ok, I see the logic, but nuclear weapon use is the brightest red line in the world. If there's anything a government wouldn't be forgiven for, it's that. I can't imagine how the calculus for the US would work out in favor given the risk. (Of course that assumes rationality, which one could certainly argue is lacking, but even still.)
Also 1000ft is an upper estimate, right? It's certainly possible the MOPs were sufficient.
It’s possible the MOP was sufficient but I suspect not. Probably parts of the facility are shallower and others are deeper, such is the topology of a mountain.
If you ever engage with what Daniel Ellsberg said, or US plans in north korea or vietnam, you’d know just how close the US comes to actual use in war. It’s never off the table. They are currently concerned with peer competition with China. There is likely a faction that would propose to attempt to show american strength on an unarmed target just like we did with Japan.
However at this juncture i’m starting to think this is all a show and they only care about the optics. Iran has already moved its equipment out of Fordow. However if the Iran war continues, expect things to get increasingly ugly.
Bunker buster is not necessarily a solution for this. It was created for normal bunkers, WW2 style of construction. What they have in Iran are construction sites very deep in the mountains. I wouldn't be surprised if this type of bombs can't do more than superficial damage to the sites.
GBU-57 reaches 200ft depth, Fordow is 300ft. The seismic wave of explosion at 200ft of several tons of TNT would reach 300ft with pretty damaging energy.
And, if it weren't enough, you can always put a second bomb into the hole made by the first one.
To the commenters below:
- nobody would let Iran to come even close to remilitarizing again. No centrifuges, and no placing them or anything similar under ground, etc.
- I do think that US may get involved in enforcement of no-fly zone over Iran. The no-fly is necessary, and Israel just doesn't have enough resources. The further scenario that i see is https://news.ycombinator.com/item?id=44343063
- jugding by, for example, the precise drone strikes on the top military commanders, Israel has had very good intelligence from Iran, so i'm pretty sure that general parameters like the depth were well known to them (the public statement of 300ft may be a lie, yet the point is that US and Israel know the depth and thus weapons to use)
The equipment in the facility isn't bolted into the limestone though. The facility is inside ultra high performance concrete and if the Iranian engineers had two braincells, dampening layers. They were building it for this moment after all.
> - nobody would let Iran to come even close to remilitarizing again. No centrifuges, and no placing them or anything similar under ground, etc.
How would they enforce that? It is underground, they can't exactly monitor what is down there with satellite photos. There'd need to be something like a blanket ban on underground mining across the whole of Iran and probably a country-wide occupation to enforce the ban. Otherwise it seems quite difficult to identify where the hypothetical centrifuges are.
Supposedly we dropped six, but I'm interested in any information that comes out about the final damage to see if this was sufficient. Ideally this would be the beginning and end of our direct engagements in this conflict.
EDIT: I kind of wish you had broken your "commenters below" piece into separate replies, but I assume this one was directed at me:
> - I do think that US may get involved in enforcement of no-fly zone over Iran. The no-fly is necessary, and Israel just doesn't have enough resources. The further scenario that i see is https://news.ycombinator.com/item?id=44343063
I didn't even consider a no-fly zone, and perhaps. I mean at this point, the current Iranian regime is in the most precarious situation it has ever been in whether they go for the kill against Ali Khamenei or just keep picking out the people below him and the IRGC's ability to fight. But if we do this, then we, and I guess I mean we now that we've actually bombed them, then we're committing to more than just taking out their nuclear capabilities, but we're committing to seeing a full regime change come to fruition.
To be blunt, given our most recent history in Iraq and Afghanistan, I'm still very much of the opinion that the least amount of American involvement, the better. If our bombs help curtail Iran's nuclear weapon R&D and we didn't lose a single B-2 in the process, then great, we've done some good for the world[1], but our track record on seeing regime changes through to the end has been less than fabulous.
[1] Still waiting to see how successful the mission was towards this goal by the way.
> you can always put a second bomb into the hole made by the first one
This is tremendously difficult. There is nothing unclassified to suggest we can do this. (There is also no evidence it didn’t occur. Just clarifying the borders of the fog of war here.)
"At 04:30 on the morning of 13 February, two F-117 stealth bombers each dropped a 910 kilograms (2,000 lb) GBU-27 laser-guided bomb on the shelter. The first bomb cut through 3 metres (10 ft) of reinforced concrete before a time-delayed fuse exploded. Minutes later, the second bomb followed the path cut by the first bomb."
> nobody would let Iran to come even close to remilitarizing again. No centrifuges, and no placing them or anything similar under ground, etc.
Well given that we've been trying to stop that for many years, I doubt its within the US's gift to change that.
Also what has iran got to loose now? like its already being bombed to shit. It's lost a generation to the iran/iraq war, why not another one where they take the USA, israel and saudis with them?
> I do think that US may get involved in enforcement of no-fly zone over Iran.
that sounds like a forever war. Moreover trump doesn't have the attention span to deploy a nofly zone for any length of time.
also, have you see the size of iran?
> Israel has had very good intelligence from Iran, so i'm pretty sure that general parameters like the depth were well known to them
yup, but the performance of munitions is unknown. Moreover they are not actually going to tell anyone the real results of the strike. Can you imagine generals telling Hegseth that his plan idea has failed because the clearly articulated unknowns came to pass. let alone trump?
They had pinpoint accurate information about a lot of senior leaders, that seems a lot harder to know than a stationary facility's location and layout.
Tracking a person actually seems pretty easy to do. Hack their phone, launch ze missiles. Obviously not trivial, but it is pretty easy to imagine a chain of events involving a little social engineering and a little spycraft involving the major tech companies. The Iranians thought they were mid-negotiations and assassinating their leadership seems counterproductive even in hindsight, I doubt they were using heightened opsec.
Getting the layout of an underground facility, on the other hand, is quite hard to do even on purpose. They'd really want the engineering plans I suppose - which should be quite secure even on a bad day. I wouldn't assume it was secure but it'd be harder than finding senior leadership who often go out in public or to their kids school plays in a regular year.
So facts are thin on the ground currently. More will become clear in the coming days. I've heard different accounts all the way from 12 bunker busters were used on Fordo to none were used and the entrance was bombed after Iran was warne, kinda like a warning shot, to say "we can get you".
What Iran does next depends on the extent of the damage. It could be nothing. It could be a token response. It could be escalation.
But so far Iran has been the only rational actor in this region. Iran has been attacked with justification. Anytime someone says "preemptive strike" they mean "attack without justification". Their responses have been measured, rational, justified and proportionate.
When Israel tried to previously escalate the conflict with Iran and drag the US into war with Iran, Iran just didn't take the bait. And this is despite Israel assassinating government officials, bombing Iranian embassies and bombing Iran for absolutely no reason.
> But so far Iran has been the only rational actor in this region. Iran has been attacked with justification. Anytime someone says "preemptive strike" they mean "attack without justification". Their responses have been measured, rational, justified and proportionate.
Either I'm misunderstanding (or misreading) something, or at least one of these sentences accidentallied a negation.
Thanks for trying to make this into a technical discussion.
I just realised that this bomb is not the same as the so called Mother of all bombs, which by the way has so far only been used once also by trump. That's the gbu 43. Why did they find
it necessary to build an even bigger bomb? I wonder if they anticipated strikes on the me.
As to your other point iran seems to have a decent level of education. Building an entire home grown nuclear program under sanctions is impressive.
The MOP is meant for a different use than the MOAB, it isn't about size. The MOAB is meant for surface destruction, the MOP is a penetrating ordinance meant to go deep through rock before eventually exploding.
Different outcomes. Moab is fuel air explosion and causes massive pressure wave disruption, it's usable against tunnels but operates on a different principle. Bunker buster is an earth penetration weapon to make a camouflet happen and destroy structural integrity.
> A camouflet, in military science, is an artificial cavern created by an explosion; if the resulting structure is open to the surface it is called a crater.[1]
The GBU-57 used here is an outgrowth of the demonstrated inadequacy of traditional bunker busters bombs used in the Middle East after 9/11. They needed something more specialized for deep penetration than the old bunker busters. This was kind of a stopgap weapon that works pretty well but the size limits the practicality.
US is developing a new generation of purpose-built deep penetration bombs that are a fraction of the size of the GBU-57.
Case hardening. Making something which if propelled fast enough (secondary issue) and with a G force resisting detonator (secondary issue) which has sufficient integrity and inertia to penetrate as deeply as possible before exploding. Materials science in making aerodynamic rigid, shock tolerant materials to fling at the ground.
I am sure the materials science aspects have come along since ww2, as has delivery technology, but I'd say how it goes fast, hits accurately and explodes is secondary to making a case survive impact and penetrate.
I would posit shaped charges could be amazing in this, if you could make big ones to send very high energy plasma out. I'm less sure depleted uranium would bring much to the table.
(Not in weapons engineering, happy to be corrected)
I'm not sure you would want a shaped charge unless you guarantee it was pointing in the right directionatthe right time. Modern bunker design usually includes deflection tactics.
I was guessing either tungsten or depleted uranium, as for APDS, but the bomb's average density is only about 5 g/cc (14 tonnes in 3.1 m³). Length of 6.2 m times 5 tonnes per cubic meter gives a sectional density of 31 tonnes per square meter, which is about 15 meters of dirt. So Newton's impact depth approximation would predict a penetration depth one fourth of the reported 60-meter depth.
I don't know how to resolve the discrepancy. The plane wouldn't fly if the bomb weighed four times as much. Maybe most of the bomb's mass is in a small, dense shaft in the middle of the bomb, which detaches on impact?
> Length of 6.2 m times 5 tonnes per cubic meter gives a sectional density of 31 tonnes per square meter, which is about 15 meters of dirt. So Newton's impact depth approximation would predict a penetration depth one fourth of the reported 60-meter depth.
This seems to assume that the weapon would penetrate until it displaced an equal amount of dirt by mass, which seems like nonsense. Why would that be the case?
A system described in the 2003 United States Air Force report called Hypervelocity Rod Bundles[10] was that of 20-foot-long (6.1 m), 1-foot-diameter (0.30 m) tungsten rods that are satellite-controlled and have global strike capability, with impact speeds of Mach 10.[11][12][13]
The bomb would naturally contain large kinetic energy because it moves at orbital velocities, around 8 kilometres per second (26,000 ft/s; Mach 24) in orbit and 3 kilometres per second (9,800 ft/s; Mach 8.8) at impact. As the rod reenters Earth's atmosphere, it would lose most of its velocity, but the remaining energy would cause considerable damage. Some systems are quoted as having the yield of a small tactical nuclear bomb.[13] These designs are envisioned as a bunker buster.[12][14] As the name suggests, the 'bunker buster' is powerful enough to destroy a nuclear bunker.
Shape can change it to be arbitrarily bad; 14 tonnes of 5-micron-thick Eglin steel foil spread over a ten-block area wouldn't penetrate anything, just gently waft down, although it could give you some paper cuts. I suspect it can't make it much better, except in the sense of increasing sectional density by making the bomb longer and thinner, which we already know the results of.
Velocity doesn't enter into Newton's impact depth approximation at all. It does affect things in real life, but you can see from meteor craters that it, too, has its limits.
Target characteristics, no idea, but in a fast enough impact, everything acts like a gas. It's only at near-subsonic time scales that condensed-matter phenomena like elasticity come into play. Even at longer time scales the impact can melt things. This of course comes into conflict with the design objective of the bomb acting solid, so that it penetrates the soil instead of just mixing into it, and can still detonate when it comes to rest. I feel like buried plates of the same metal would have to be able to deflect it? And there are plenty of other high-strength alloys.
I did some quick calculations: The energy of the impact from the stored kinetic energy gained by falling fro 15,000m is about the same as half a kiloton of TNT going off. That's focused into a circle just 80cm in diameter.
Your calculations appear to be off by a factor of ~1000. Not half a kiloton, but half a ton (~500kg), assuming fall in a vacuum (upper bound on impact energy):
Python 3.10.12 (main, May 27 2025, 17:12:29) [GCC 11.4.0] on linux
Type "help", "copyright", "credits" or "license()" for more information.
MOP_potential_energy = 13607*9.8*15000 # E = m*g*h
MOP_potential_energy
2000229000.0
TNT_specific_energy = 4.184e9/1000 # joule/kg
TNT_specific_energy
4184000.0
MOP_potential_energy/TNT_specific_energy
478.0662045889101
Yet setting off half a tonne of TNT on the ground, or even just under it, won't penetrate 60 meters deep, or even 15; it will just blast open a shallow crater. A shaped charge will do only a little better.
No real secret sauce, the weapon weighs almost 30,000lbs and most of it is just hardened metal to make it heavy. The warhead is only ~5,300lbs of explosive
It's not entirely home grown if they were part of the NPT is it? Signing the NPT (a pinky promise not to develop weapons) means other countries then help you develop nuclear energy, which of course has a lot of overlap to weapons tech...
- MOP: High penetration; most of its payload is not explosive. (Something heavy). Designed so its body, fuse, explosives etc remain intact after penetrating deep.
- MOAB: Fuel air explosive for massive blast effect.
I doubt anyone here works in defence materials sciences and like the rest of the world would be 49/51 regarding voting intention. I've never voted for a pro war party fwiw but if I'd been of an age, I would have called ww2 a just cause war.
This isn't a just cause and it's not even a war. It's state sanctioned terror. I don't know it has ism in it.
Australian legal opinion says it's unlikely a credible defence in international law exists for this attack. It may redefine the norms for (un)lawful acts by the state, other states, weak and powerful will undoubtedly reflect on this.
It's also being claimed a success. Words like "obliterated" used. Time tends to tell a story there. I think it's a little too soon to say how successful these strikes were, tactically or strategically.
Yes, bunker buster was used. Per a different source:
> It included a strike on the heavily-fortified Fordo nuclear site, according to Trump, which is located roughly 300 feet under a mountain about 100 miles south of Tehran. It's a move that Israel has been lobbying the U.S. to carry out, given that only the U.S. has the kind of powerful "bunker buster" bomb capable of reaching the site. Known as the GBU-57 MOP (Massive Ordnance Penetrator), the bomb can only be transported by one specific U.S. warplane, the B-2 stealth bomber, due to its immense 30,000 pound weight.
I read the article in full. There is no confirmation of using GBU-57 in the strike. Re-read your quoted section.
The English is a bit convoluted, but does do not confirm usage.
Tin foil hat engaged: For all we know special forces detonated plastic explosives deep on site after doors were blown off.
More seriously: Nothing has been confirmed except a Truth Social post.
Can I say again how deeply silly this munition is? What's special about a GBU-57 isn't its explosive force. It's that the bomb casing is made out of special high-density ultra-heavy steel; it's deliberately just a super heavy bomb with a delayed fuse. It is literally like them dropping cartoon anvils out of the sky.
From what I've read, the idea is that they keep dropping bombs into the same bomb-hole that previous sorties left, each round of bombs drilling deeper into the structure.
>Can I say again how deeply silly this munition is?
If it is silly and it works, then it is not silly. If I remember correctly you have good cryptography skills. Rectothermal/rubber hose cryptoanalysis is quite silly too, but breaks AES,RSA,ECC and post quantum crypto schemes in 30 seconds.
> Can I say again how deeply silly this munition is?
Honestly, I'd rather you not. For those who are more personally familiar with warfare and combat operations, consistently describing any sort of bomb as "silly" is childish and inaccurate to the point of making me wonder if there's an ulterior motive with your description.
The typical person compartmentalizes between a weapon's use in military operations and its engineering. You see similar dynamics with things like military aircraft at air shows. Where kids and adults alike enjoy the demonstrative operation of the machines without ruminating on how many human souls were negatively affected by them.
Compartmentalization is a coping mechanism. That children are exposed to similar military engineering in such a way to make it enjoyable does not negate the nature of a bomb, tank, or machine gun.
So many armchair quarterbacks in this thread. You haven’t defined how silly this is beyond your feelings. Are you a munition expert? If you were an AF general given this order, what tactic would you choose excluding a nuke?
The same bomb hole tactic is an untested theory (which may be ineffective but not silly) but we’ll know more later this week once MAXAR surveillance and other independent or IAEA analysis rolls in.
I'm not an expert. I just think dropping giant anvils from the sky is Loony Toons tactics. Maybe it works great! I don't know! But it's worth knowing how these things work, and how they work is: they're just super super heavy.
If the weather is good and no jamming of gps it’s very practical. The bunker buster is basically a very large jdam and their precision is around 5 meters iirc.
When I was doing a postdoc in Germany I shared an office with a woman from Morocco so my office was a meeting point for many islamic woman including one from Iran who complained bitterly about how women were treated in her country but who did get the opportunity to get an advanced education.
The parent post was about Iranian women jobs getting jobs in engineering. Whatever restrictions are on them, they don't seem to have trouble getting STEM education.
I took the contradiction as the point: that they are oppressed and yet, surprisingly, not with respect to educational opportunity
> including one from Iran who complained bitterly about how women were treated in her country but who did get the opportunity to get an advanced education
Iran has massive earthquake risks. For reasons unassociated with nuclear bunkers they do a lot of research into (fibre, and other) strengthened cement construction. With obvious applications to their nuclear industry of course.
Another unrelated point, a significant number of Iranian civil engineering graduates are women. A somewhat dichotomous economy, when you consider the theocratic restrictions on costume and behaviour.