6 ms·

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 w

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.

ggm 1y ago
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.
- anonymars 1y ago
  Today's word of the day for me https://en.wikipedia.org/wiki/Camouflet https://en.wikipedia.org/wiki/Camouflet > 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]
jandrewrogers 1y ago
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.
- hooo 1y ago
  What’s the core technology that enables them? It is crazy how deep the GBU-57 can get before detonating
  - giantg2 1y ago
    It's not that crazy. It's simple physics. Drop a 15 ton metal lawn dart from 50,000 feet and it has a lot of energy.
  - ggm 1y ago
    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)
    - giantg2 1y ago
      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.
  - kragen 1y ago
    According to public information, Eglin steel. 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?
    - barrkel 1y ago
      How much does refinements of shape, terminal velocity, target characteristics change the calculation?
klipt 1y ago
> an entire home grown nuclear program 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...
giraffe_lady 1y ago
[flagged]
- ggm 1y ago
  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.
  - yencabulator 1y ago
    > Australian legal opinion says it's unlikely a credible defence in international law exists for this attack. The international community has known for a while that USA and Israel are both belligerent nations. https://en.wikipedia.org/wiki/International_Criminal_Court#United_States https://en.wikipedia.org/wiki/International_Criminal_Court#U...
the__alchemist 1y ago
- 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.
_heimdall 1y ago
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.
testrun 1y ago
It seems that they have help from the Russians. Putin last week mentioned that there are quite a few Russian nuclear scientists in Iran.
- econ 1y ago
  200+

ggm 1y ago

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.

anonymars 1y ago
Today's word of the day for me https://en.wikipedia.org/wiki/Camouflet https://en.wikipedia.org/wiki/Camouflet > 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]

jandrewrogers 1y ago

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.

hooo 1y ago
What’s the core technology that enables them? It is crazy how deep the GBU-57 can get before detonating
- giantg2 1y ago
  It's not that crazy. It's simple physics. Drop a 15 ton metal lawn dart from 50,000 feet and it has a lot of energy.
- ggm 1y ago
  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)
  - giantg2 1y ago
    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.
- kragen 1y ago
  According to public information, Eglin steel. 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?
  - barrkel 1y ago
    How much does refinements of shape, terminal velocity, target characteristics change the calculation?

klipt 1y ago

> an entire home grown nuclear program 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...

giraffe_lady 1y ago

[flagged]

ggm 1y ago
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.
- yencabulator 1y ago
  > Australian legal opinion says it's unlikely a credible defence in international law exists for this attack. The international community has known for a while that USA and Israel are both belligerent nations. https://en.wikipedia.org/wiki/International_Criminal_Court#United_States https://en.wikipedia.org/wiki/International_Criminal_Court#U...

the__alchemist 1y ago

- 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.

_heimdall 1y ago

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.

testrun 1y ago

It seems that they have help from the Russians. Putin last week mentioned that there are quite a few Russian nuclear scientists in Iran.

econ 1y ago
200+