[HN Gopher] John A Phillips
___________________________________________________________________
John A Phillips
Author : barry-cotter
Score : 155 points
Date : 2022-09-02 07:38 UTC (15 hours ago)
(HTM) web link (nuclearprinceton.princeton.edu)
(TXT) w3m dump (nuclearprinceton.princeton.edu)
| ackbar03 wrote:
| What a badass. He even has Aristotle as his middle name and his
| company's name
| jiggywiggy wrote:
| Just shame he ends up dedicating his time to data
| jamesrom wrote:
| ... instead of nuclear bombs?
| jiggywiggy wrote:
| We have so many data companies. He clearly show ability to
| build some "real" world applications.
| capableweb wrote:
| Instead of safety devices ("slowly moved away from creating
| nuclear things and invented a motorcycle air bag").
|
| Surely that would have a better impact on the world instead
| of aiding political campaigns with machine learning, ads
| and data.
|
| Edit: Yeah, reading his Wikipedia page, I'm 100% sure he
| could have spent his time better.
|
| > The experience he had gained during his campaigns
| obtaining the voter list from the state and using it for
| campaign purposes led him [...] to found Aristotle, Inc.
| [...] a consulting firm for political campaigns [...] It
| specializes in combining voter lists with personal data
| from other sources (such as income, gun ownership or church
| attendance) and data-mining, to assist with micro-targeting
| of specific voter groups; as of 2007, its database
| contained detailed information about ca. 175 million U.S.
| voters and it had about 100 employees.
| danbruc wrote:
| ... if you happen to have a critical mass of enriched Uranium [1]
| laying around in your garage.
|
| [1] Preferably not in a single lump.
| m_mueller wrote:
| isn't getting the weapons grade Uranium (or Plutonium) what is
| most difficult about making a bomb anyways? My assumption is,
| once a terrorist group has achieved that, and has transported /
| smuggled it to their target, it's game over anyways. Harbor
| towns must be particularly vulnerable to this, considering the
| amount of shipping containers going through there...
| tsimionescu wrote:
| No, making a true atomic bomb is extremely difficult science
| and engineering.
|
| Now, a dirty bomb, which is just a conventional explosive
| together with radioactive material - designed to spread
| radioactive material instead of releasing the fission energy
| into one giant explosion - is easy to create, but not that
| much more effective than just a conventional bomb. It would
| trigger a massive cleanup effort, and it would surely give
| some people cancer later down the line, but it wouldn't be
| that spectacular.
| danbruc wrote:
| No, it is not that difficult, at least if you are fine with
| not having the most efficient weapon. You take a metal
| pipe, put a lump of Uranium and some explosive at each end
| and to a first approximation you are done. The USA did not
| even test their gun type design before dropping it onto
| Hiroshima because it was so simple that they were confident
| that it will just work.
| danbruc wrote:
| For a simple bomb you want Uranium, Plutonium emits too many
| neutrons which are likely to cause a small chain reaction
| while your critical mass is in the process of forming and
| this predetonation can then blow everything apart before a
| proper critical mass has been formed. A gun type design where
| you just smash two subcritical lumps of metal into each other
| is, as I remember, nearly impossible to achieve with
| Plutonium you can realistically produce.
|
| EDIT: Interestingly another commenter says that this actually
| was a Plutonium design.
| gonzo41 wrote:
| Extracting u238 from 235 is a hard process. Using flourine
| gas, it requires you to turn an ore, to a metal, then to gas
| and then back to metal. If terrorists can get that done they
| should quit terrorism and just open a chemical plant
| GTP wrote:
| But they would not, as terrorism isn't about making money.
| SideburnsOfDoom wrote:
| Terrorism isn't about solving extremely hard chemical
| engineering scaled process problem either.
| throwaway0a5e wrote:
| It's not about becoming a commercial pilot or truck
| driver either but those are a means to an end.
| SideburnsOfDoom wrote:
| I'm not aware of any terrorist who actually became a
| commercial pilot, merely those who took a few lessons
| (1). And I think that's at the upper end of the lengths
| that terrorists will go to: Past a certain point the low-
| tech approaches are just way more "bang for the buck", so
| to speak. And past a certain specialisation of skills,
| it's way more effective to get that high-paying job and
| donate to political causes.
|
| 1) https://www.sandiegouniontribune.com/lifestyle/people/
| sdut-g...
| ddalex wrote:
| I feel(*) it's not about the critical mass, but the critical
| density - that's why you need strong compression (either
| chemical explosives, or xrays from a smaller nuclear bomb) to
| trigger the explosion (exponential runoff chain reaction).
|
| So this guy figured out how to create the critical density for
| 2k USD worth of components, which is actually the "hard" part
| of building a bomb.
|
| (*) not a nuclear physicist
| nine_k wrote:
| You need to compress not the solid chunks of metal, but the
| gaseous / plasmatic plutonium after a few microseconds past
| the critical point. The problem is that it emits neutrons too
| quickly, and the thermal runaway of the critical mass happens
| too quickly. If you do not hold the plutonium together, it
| will just fly in all directions before enough of it has
| reacted.
|
| No static casing us string enough; a dynamic caring made of
| highly compressed results of a conventional explosion works.
| danbruc wrote:
| You don't have to compress the material if you have enough
| but if you can compress it, then you can achieve detonation
| with less material.
| thombat wrote:
| But it's a plutonium design, which according to common
| wisdom is too fissile for slow assembly but needs both
| compression and enough inertia to stop it from exploding
| with a very low yield.
| danbruc wrote:
| I meant in general, for Plutonium you realistically need
| an implosion type design, but I think theoretically you
| could even have a gun type Plutonium bomb, just making
| clean enough Plutonium is totally uneconomical.
| consp wrote:
| And you still need a looooong barrel and a fast moving
| plutonium part (see the thin man design on wikipedia and
| then extrapolate from there) even creating near close
| enough pure plutonium since economically you won't have
| pure.
| bayouborne wrote:
| "Parsons' first order of business was the plutonium gun.
| Because it needed a muzzle velocity of at least 3,000
| feet per second it would have to be 17 feet long. It
| should weigh no more than a ton, a fifth of the usual
| weight of a gun that size, which meant it would have to
| be machined from strong high-alloy steel. It would not
| require rifling but needed three independently operated
| primers to make sure it fired. Parsons arranged for the
| Navy's gun-design section to engineer it."
|
| - Richard Rhodes - The Making of the Atomic Bomb
| wnkrshm wrote:
| Can you rotate a plutonium "carousel" fast enough and
| then make all the pieces crash into a wall, onto each
| other...
|
| Edit: Idk, something about flywheels, they can store a
| huge amount of energy and release it very quickly.
| danbruc wrote:
| Probably not, we are talking really short timescales
| here. The nuclear explosion is over before you can even
| see the first crack in the housing of your bomb.
| [deleted]
| [deleted]
| adastra22 wrote:
| It's not hard to get uranium. You can buy it on Amazon. It is
| enriched uranium that is hard to come by. I'm guessing the low
| cost for this project is that he found a way for low enriched
| uranium to go supercritical.
| danbruc wrote:
| Enriched Uranium was of course implied but I edited the
| comment now. Another commenter mentioned that it was a
| Plutonium design, in which case the Plutonium was almost
| certainly not part of the bill.
| thombat wrote:
| Apparently it's a plutonium design, which is interesting
| because if it's using implosion then the detonation timing and
| quality of the explosives is commonly thought to be critical
| (notably the "Fat Man" plutonium bomb was tested before being
| dropped on Hiroshima, whereas the uranium bomb design wasn't
| all-up tested before Nagasaki as it was held to be obviously
| reliable)
| mjfl wrote:
| I mean if you are starting from plutonium and assuming it's
| gonna cost $2k you are lying to yourself. I can only
| imagine... "Step 1. buy 5 kg of plutonium for $1k".... I
| think plutonium is 4 mil per kilogram according to google.
| narag wrote:
| It seems you have the names and cities reversed.
| danbruc wrote:
| Hiroshima / 1945-08-06 / Little Boy / gun type Uranium /
| untested
|
| Nagasaki / 1945-08-09 / Fat Man / implosion type Plutonium
| / tested with Trinity 1945-07-16
| dilyevsky wrote:
| which means that's even harder to come by bc unlike uranium
| there's no naturally occurring plutonium on Earth
| topynate wrote:
| I imagine that between the '40s and '70s many of the really
| hard problems became a lot easier. E.g. using solid-state
| electronics for the timing, modelling shaped charges as a
| textbook exercise rather than a research problem, etc. What
| surprises me is that he managed to get a dirt-cheap
| initiator.
| alfiedotwtf wrote:
| > using solid-state electronics for the timing
|
| Curious... is timing actually that big of a deal when
| you've already got critical mass? What would happen if you
| just dropped one half critical mass from 1m above to the
| other half?
| MertsA wrote:
| With an implosion type bomb you need to make sure that
| the shockwave from the explosives hits the plutonium pit
| all around it almost simultaneously. If there was a
| portion where the explosive shockwave was delayed then
| the forces on the rest of the pit are going to tend to
| "squish" it out towards the portion where the explosion
| hasn't hit it yet. This asymmetrical compression means
| now you don't get the ideal compressed sphere so now
| while it's still going to reach criticality, it's going
| to be blasted apart with much less of the fissile
| material being fissioned. A great real world example of
| why timing is so critical is the first North Korean
| nuclear bomb test.
|
| https://en.wikipedia.org/wiki/2006_North_Korean_nuclear_t
| est...
|
| They had a yield of less than a kiloton. Obviously way
| greater than conventional explosives but it should have
| been an order of magnitude more powerful.
|
| In order for the explosives to form that crucial
| explosive lense you need detonation across numerous
| points on the outside simultaneously so you need a
| detonator that's extremely consistent on timing so a
| simple resistive detonator with some primary explosives
| packed around a filament is not going to be effective.
| The method of choice is an exploding bridgewire design.
| Basically you have a thin wire and you pass enough
| current through it to vaporize the wire so quickly that
| the wire itself generates the initial shockwave as it
| gets turned into plasma. The rest of the explosive lense
| is just two different types of explosive with different
| propagation velocities. The two are combined with a
| parabolic (or hyperbolic, I forget off the top of my
| head) face between the two layers so that the explosion
| that started from a single point goes from convex to
| concave so it hits the outside of the pit all at the same
| time.
|
| If you simply dropped a half-critical mass onto another
| and it was prompt critical then yes, it would explode,
| but with not nearly as much energy being released as a
| proper nuclear weapon.
| smilespray wrote:
| It would preignite and fizzle. No nuclear yield, but a
| pile of radioactive stuff.
| alfiedotwtf wrote:
| ah, ok thanks for that.
|
| Even though OP had their research taken away, I wonder
| how long it will be before you could simply ask GPT-3 how
| to make a nuke for under $2k
| manholio wrote:
| Maybe he designed a geometry that can achieve the required
| implosion speeds with slow, easily available explosives ex.
| AN, KN, AP etc. The size of the device (a container) seems
| to suggest this.
|
| The actual initiation is the easy part and would have been
| easy in the 70s, exploding wires that are subjected to a
| number of kilo Ameperes by some kind of avalanche, solid
| state switch.
| topynate wrote:
| I meant a modulated neutron initiator, not the explosive
| detonator. India was still using vapour deposition of
| polonium to make theirs, around the same time. I'm no
| engineer but that sounds like it costs a lot more than
| $2000.
| Xx25 wrote:
| HN never ceases to surprise! I am really curious how you
| happen to know such details about India's nuclear bomb.
| danbruc wrote:
| The internet probably. [1]
|
| [1]
| https://nuclearweaponarchive.org/India/IndiaSmiling.html
| baybal2 wrote:
| [deleted]
| atemerev wrote:
| The cheap initiator is a solved problem since 1989.
| topynate wrote:
| Yeah, we've got better at making neutrons since 1970.
| Mostly this is a good thing!
| thombat wrote:
| Since his design dates from 1976, you reckon it would be
| cheaper now?
| madaxe_again wrote:
| Or you can just buy a (literal) boatload of smoke detectors
| (americium) and medical waste (curium) and make an americium
| bomb - or use a neutron gun to transmute your americium into
| plutonium via curium.
| danbruc wrote:
| The last time someone was going down that road it did not end
| too well.
| oxfordmale wrote:
| ....and you don't mind being lifted out of bed at 3am by the
| security services in your country, face a lengthy interrogation
| and a potential prison sentence.
| bluelightning2k wrote:
| We need ctrl+Z for inventions.
| m_mueller wrote:
| Consider the potential unintended consequences of de-inventing
| the bomb. The cold war would probably have been hot in this
| case.
| hackerlight wrote:
| Missing the point. If lone wolf terrorists have access to
| engineered viruses or atomic bombs, that's bad in a unique
| way, because there's probably going to be >= 1 unhinged
| people who will use it, and all you need is 1.
|
| If we're dealing with a world where only _states_ can access
| the tech, the probability that >= 1 state will be
| sufficiently unhinged to use it is far lower.
|
| We will eventually need a metaphorical CTRL+Z on tech,
| probably through government power and maybe world government.
| The fragility of us as organisms is about constant, but tech
| is going to keep getting better and cheaper.
| schiffern wrote:
| Lone wolf terrorists wouldn't result in annihilating ~every
| city on Earth, but state actors might.
|
| One nuclear bombing is bad. 1,000 nuclear bombings is
| worse. Risk = probability x outcome.
|
| It's not a choice between only state actors having access
| vs only lone wolf terrorists. The issue of nuclear
| disarmament is choosing between states + terrorists (the
| status quo) vs only terrorists.
| hackerlight wrote:
| Correct when it comes to present day nukes, maybe not if
| we're talking engineered viruses or some as yet
| undiscovered weapon. Anyway, I think the point stands
| that there's significant novel risks posed if individuals
| of the future are capable of destroying cities if they
| feel like it, and there will unfortunately need to be a
| paradigm shift around privacy and government involvement
| if that day comes.
| schiffern wrote:
| Perhaps the Great Filter is, "are you smart enough, _as a
| species_ , to put the (various) genies back in the
| (various) bottles?"
|
| Different genies call for different bottles, naturally.
| nine_k wrote:
| We don't have a Ctrl-Z, but we have a sort of a pause
| button. Non-proliferation agreements, IEAE inspections,
| bans on selling certain products that are key enablers of
| production of atomic weapons.
|
| With viruses, it's a bit harder, medical work us hard to
| distinguish from weapons work.
| hackerlight wrote:
| This is again referring to the current state of affairs
| and therefore misses the point. These controls work for
| now because such tech is expensive and difficult. A
| future where that's not the case isn't so unlikely.
| amelius wrote:
| It's either that or ctrl+Z for humanity.
| LargoLasskhyfv wrote:
| https://en.wikipedia.org/wiki/Invention_Secrecy_Act
|
| https://en.wikipedia.org/wiki/Born_secret
| quickthrower2 wrote:
| Well
|
| > Phillip's work was confiscated by the FBI
|
| But that is probably more of a ctrl+Z in the sense of "pause
| process"
| NavinF wrote:
| >Phillip's professor has said that the design would likely work,
| but his design was not actually built
|
| Ok so it's not really $2k nor is it an atom bomb.
| highwaylights wrote:
| err... good?
| imdsm wrote:
| I'm not sure if I follow. It was a design for an A bomb that
| would cost $2k, ergo, a $2k A bomb. Obviously have to adjust
| for time and inflation.
| thombat wrote:
| It's like a $5 meal kit for a "BBQ meat feast" that has the
| recipe, spices, but doesn't include the meat. So once you've
| visited the specialist butcher and spent a lot more money,
| now you have the $5 feast.
| blackoil wrote:
| The research was not sold for 2k. It was expected BOM for
| ingredients listed in the recipe.
| thombat wrote:
| If this paper (that none of us can ever see) really
| included the plutonium in that BOM then it would be
| interesting to know how he derived a price for it, since
| it's not really a openly traded commodity.
| topynate wrote:
| Funny enough, Pu-238 was on the market at one point (with
| plenty of restrictions). It was used to power pacemakers.
| It's still used for spacecraft.
|
| I'm not sure how expensive it was in the '70s but it is
| very expensive now. American production is supposed to be
| scaling up, but only to about 1.5 kg a year.
| bookofjoe wrote:
| https://osrp.lanl.gov/pacemakers.shtml
| thombat wrote:
| But Pu-239 is presumably the stuff for this hobby
| project? The one-click price for that is hard to find,
| even if you bring your own take-out container.
| topynate wrote:
| Yes, I was looking for a point of comparison. Pu-239 is
| probably also quite expensive, as both isotopes are
| prepared by using a reactor to irradiate stuff. Only way
| I can see a "$2k" cost as relevant is if it's the cost to
| someone who's already acquired the nuclear material.
| arethuza wrote:
| I'd love to see the BOM for that.
| LightG wrote:
| Badam tsk.
| LightG wrote:
| So I can cosplay as Raven out of Snowcrash ... for real!?
| deepstack wrote:
| The real question is every human being have ability to have
| create these kind of bomb, I can see civilisation can be wiped
| out in an instance at our current level of
| mental/psychological/spiritual maturity.
| atemerev wrote:
| Nuclear simulations are my hobby, and I have a few pet projects
| in the area. It is impossible to build a bona fide nuclear device
| for $2k (it is possible to build a dirty bomb with this budget,
| but it is not interesting in any way).
|
| To achieve sustainable prompt criticality, you need high-quality
| starting material with low spontaneous fission, and a fast
| assembly (microseconds). "Gun-type" assembly is not used anymore
| even by new nuclear programs, as it is very inefficient (and
| still requires quite a lot of precision engineering). With
| implosion assembly, you need to learn quite a lot about shock
| compression, numerical simulations of detonations, and again it
| requires some precise engineering. "A nuclear bomb is like a
| half-ton Swiss watch", as somebody have said.
|
| I believe it is possible to build a nuclear device from scratch,
| but you need a few years, explosion testing rigs and radiography
| equipment, a team of engineers and physicists, and a few millions
| budget. If you don't have starting material, it will be much more
| expensive.
| varjag wrote:
| $2k in 1978 money. More like 15k now!
| floodle wrote:
| I get $9,088.22 on an online inflation calculator. Although I
| do wonder whether uranium is included in the consumer price
| inflation index!
| varjag wrote:
| I prefer to compare it to other industrial products.
|
| _1973 Ford F-100 (Sixth Generation): $2,889 - $17,387.85_
|
| https://www.thedrive.com/news/34333/heres-how-much-the-
| ford-...
|
| Tho of course the end of decade added up to the inflation..
| the_gipsy wrote:
| So would we also get an H-bomb then? Because a 2022 car
| is much, much more technologically advanced than a 1973
| one.
| atemerev wrote:
| Thermonuclear devices require complicated X-ray
| reflection modeling, ablation modeling, and some other
| very specialized stuff which barely even have open source
| libraries for this. There are some, still.
| Nokinside wrote:
| The only step that takes time and space is creating enough
| highly enriched uranium for the bomb. You need few hundred or
| thousand centrifuges running a some time.
|
| I have a friend who is nuclear physicist working for the
| nuclear proliferation issues in international organization.
| According to him, every country would do modern boosted fission
| weapon as their first nuke, and it can take less than year when
| you have easy access to experts and modern machines. Few
| subcritical tests (easy to hide) are needed to verify that
| everything works, numerical simulations do the rest.
|
| Boosted fission weapon is still considered a fission weapon,
| but it uses fusion to boost the yield. You need a breeder
| reactor or small particle accelerator to make the necessary
| tritium but basically anyone can do it. Including North Korea.
| atemerev wrote:
| More like a few tens of thousands (if not hundreds of
| thousands) centrifuges. Anyway, states like Iran go for the
| uranium way only because enrichment plants can be hidden and
| work underground, unlike plutonium production facilities
| which require open space and a lot of running water.
| dTal wrote:
| >"Gun-type" assembly is not used anymore even by new nuclear
| programs
|
| How can you assert this with such confidence?
| atemerev wrote:
| Because A.Q. Khan and other practitioners have shown that
| even if you have weapon-grade enriched uranium, it is better
| to work out a (relatively) crude implosion device, and it
| will still work better than gun-type.
| boomboomsubban wrote:
| From Wikipedia
|
| >There are currently no known gun-type weapons in service:
| advanced nuclear weapon states tended to abandon the design
| in favor of the implosion-type weapons, boosted fission
| weapons, and thermonuclear weapons
|
| https://en.wikipedia.org/wiki/Gun-type_fission_weapon
|
| It seems like clearly the inferior method, the USSR never
| even bothered with them.
| smilespray wrote:
| Not OP. Gun-type assemblies use uranium and are very wasteful
| in terms of fissile material. State-run nuclear programs have
| all gone for implosion designs, even North Korea.
| rawoke083600 wrote:
| Somewhere / everywhere in the basements of governments, there are
| a lot of "topic/word filters" alarms going off :D
| eterevsky wrote:
| Is it actually possible to buy or produce enough fissile material
| with just $2k? What would it be? Uranium-235?
| etiam wrote:
| I've been trying occasionally for years to recover a piece of
| interview where the interviewee was musing on the consequences
| and handling of someone inventing an atomic bomb well within
| reach of possession for common citizens.
|
| The comment was roughly that it would be an outstanding technical
| achievement and probably worthy of major awards, but of course
| that's not what we'd do. More likely we'd burn the designs, lock
| the inventor up and throw away the key.
|
| It seems, given this post, that it was not literally accurate,
| but I still find it a wonderful illustration of how much
| technology is _not_ morally neutral and can lend itself more or
| less readily to constructive or destructive purposes.
|
| Really wish I could find it again, or at least attribute
| properly.
| swarnie wrote:
| > More likely we'd burn the designs, lock the inventor up and
| throw away the key.
|
| Which is depressing since nuclear armed nations dont get
| invaded or subjugated. Arguably the inventor should be given
| the noble peace prize every year going forwards.
| etiam wrote:
| Well, some sort of Nobel prize may have been mentioned in the
| awards reasoning, but the premise in this case is more in the
| spirit of '640 kilotons ought to be enough for anybody'...
|
| Nuclear armed private citizens may not get invaded or
| subjugated either, yet it's hard to see that the home atomics
| revolution would make us collectively safer on the whole.
| midoridensha wrote:
| >but of course that's not what we'd do. More likely we'd burn
| the designs, lock the inventor up and throw away the key.
|
| Which is exactly what we _should_ do (in fact, the inventor
| shouldn 't be locked up, he should be "disappeared"), if we
| want to avoid horrible destruction.
|
| I really think this kind of thing might be the answer to the
| Fermi Paradox: Just imagine if any idiot could easily construct
| not just any bomb, but a doomsday bomb that destroys the whole
| planet. The planet wouldn't last long, because sooner or later
| some mentally ill person is going to build one and set it off.
| checkyoursudo wrote:
| You could just offer (with the alternatives maybe making it a
| "can't refuse") to put the inventor to work doing something
| more benign and pay them for their skills. You could even let
| them do side projects like these at the lab so they get to
| scratch that itch.
|
| Not everyone needs to be disappeared.
| sawyna wrote:
| If we carefully think about it, someone is going to do it
| judging from the fact that the person did it purely from
| textbook based information. I'd rather think it's better to
| identify ways to build such things and prevent wide scale
| adoption in a reasonable way. Locking up people and burying
| the evidence is a short term solution. Building ways of
| resilience and to be able to thwart or diffuse such bombs or
| to make laws which make it harder to extract raw materials
| seems a good long term solution to think about.
| midoridensha wrote:
| >I'd rather think it's better to identify ways to build
| such things and prevent wide scale adoption in a reasonable
| way.
|
| But how do you do that? Suppose some new physics are
| discovered, and this makes it trivially easy to build a
| doomsday bomb using readily-available materials that simply
| can't be restricted.
|
| >Locking up people and burying the evidence is a short term
| solution.
|
| Unfortunately, yes: if it gets to my scenario above, it's
| probably just a matter of time.
|
| >Building ways of resilience and to be able to thwart or
| diffuse such bombs or to make laws which make it harder to
| extract raw materials seems a good long term solution to
| think about.
|
| Again, in my scenario, anyone with half a brain can easily
| build the doomsday bomb using stuff from the grocery store.
| We're not talking about plutonium here, we're talking about
| very common materials. How do you stop the world from being
| destroyed?
| 0x_rs wrote:
| You could deal with them that way, sure. But every other
| person after them will learn not to divulge it and take the
| best offer from other countries (submission mentions offers
| from France and Pakistan for Phillips) and give it to them,
| because you're not going to reach a worldwide consensus on
| "let's get rid of every person that develops X theoretical
| doomsday device" and others will want that edge. This seems
| so shortsighted it'd do well together with the vitrum flexile
| story. Just like engineers after WWII, during and after the
| Cold War, you'd want to give them a comfortable position
| using their talent for something more productive than
| developing military-purposes missiles. I'd be more worried
| about biochemical warfare anyway, I'm surprised there hasn't
| been any major attack with water supply as a vector.
| Xx25 wrote:
| Why bother with water supply when you can use the air flow
| :(
| danbruc wrote:
| I think I also remember that interview or maybe a YouTube video
| about it. Something like what would we do if someone discovered
| that you can put sand and magnets into a microwave with the
| plate rotating counterclockwise and it goes gigantic boom. Have
| a look at the Veritasium YouTube channel, I have very vague
| memories that it might have been there. Or maybe Vsouce or
| Kurzgesagt.
|
| EDIT: The Vulnerable World Hypothesis [1] with the Easy Nukes
| thought experiment. And this a TED talk with the author [2] and
| probably what I watched.
|
| [1] https://nickbostrom.com/papers/vulnerable.pdf
|
| [2] https://m.youtube.com/watch?v=JrjjOGI6YB4
| bmacho wrote:
| I am afraid that current AI models _are_ the black balls. For
| example it is now close to impossible to verify anything,
| even that whether the Russians nuked half of the country or
| not. (It is somehow doable with trusted chains, but can you
| _really_ trust them?)
|
| Also I suspect that hacking AI will be much more powerful
| than any hacking with hand soon.
| bob1029 wrote:
| I wouldn't argue the _current_ models are, but we are
| definitely up to our elbow in cookie jar at the moment.
| nathias wrote:
| too bad, he could have build one for himself and drive it around
| on a motorcycle and become a sovereign individual
| temptemptemp111 wrote:
| thomasjudge wrote:
| I remember reading his book when I was a kid. Amusing read, but
| he & his roomie/coauthor come across a little tech-bro-y
|
| https://www.amazon.com/Mushroom-bomb-John-Aristotle-Phillips...
| throwaway81523 wrote:
| I also read that book and thought it was pretty good (a few
| small parts were cringy). Tech bros weren't really a thing
| then, or at any rate I didn't mind it at the time. The linked
| page, which I hadn't seen before and is about what he is doing
| now: well THAT seems bro-y. Oh well.
| klabb3 wrote:
| > Phillip's work was confiscated by the FBI
|
| Typical government overreach. If you live in a rural area you
| can't rely on the government for nuclear defense. How are they
| supposed to defend themselves without nukes of their own?
| philshem wrote:
| I get it. Thank you.
| janmo wrote:
| The real nuclear terrorist threat comes from nuclear power
| plants, they are way less secure than governments want you to
| believe they are.
|
| As we now know that they go boom once there is no more cooling,
| which occurs if there is a power outage (with failure of the
| backup diesel generators) or if there is a leak in the
| waterpipes.
| junon wrote:
| This is a complete oversimplification and dismissal of the feat
| of engineering that goes into nuclear power plants.
| titoCA321 wrote:
| These plants also have armed security and other physical and
| electronic deterrents along with engineering personnel to
| respond to different crisis.
| agmz wrote:
| Another example indicating that The Great Filter is likely
| technological - I reckon most species have the technological
| capability for a few rogue individual to wipe them out completely
| before they have the capability to become truly multiplanetary,
| and therefore hedged
| bjarneh wrote:
| > and was even approached by both France and Pakistan making
| offers to buy his research
|
| Probably quite a few others as well...
| thombat wrote:
| Those were the countries offering to buy. In his position I'd
| be fearing offers of "non-financial inducements"
| tsimionescu wrote:
| Given the topic, you could almost call it "payment in
| kind"...
| alkonaut wrote:
| If you just want a bad atomic bomb, isn't it enough to put 2
| chunks of fissile (enough) material at either end of a very thick
| steel tube and shoot them together using explosives? The question
| is how you use $2k to buy or produce the fissile material,
| because if the BOM was really $2k including "weapons grade"
| fissile material then the interesting question is how to get the
| fissile material that cheaply.
|
| If the BOM is $2k _excluding_ the fissile material then... is
| that really surprising? I thought crude bomb designs were pretty
| easy to create if you have no interest in maximizing yield or
| minimizing how dirty the bomb gets?
| rich_sasha wrote:
| No expert here; apparently this requires more / more enriched
| uranium. Since enriching uranium seems to be the bottleneck,
| this is suboptimal. This is why the Hiroshima bomb worked like
| this, but the second one, in Nagasaki, worked by compressing
| plutonium with explosives instead.
|
| There's also the question of "compactness". If you want to
| carry the bomb by plane, say, it has to be light-ish and
| compact-ish, which this design lends itself less to. If you
| want to shoot it up in a rocket, this is even more important.
| hackernewds wrote:
| The article states it was the size of a U-Haul. Nothing
| flight-worthy
| ascar wrote:
| No it mentions "the actual bomb would fit in the size of a
| U-haul trailer".
| ok_dad wrote:
| Fat Man was 20k pounds, and about the size of a large
| automobile.
| HeyLaughingBoy wrote:
| Depends on the airplane you drive it into.
| mikkom wrote:
| Note that the paper is from 1976. $2000 at 1976 is totally
| different in value than it's today.
| Bakary wrote:
| I've noticed that HN is very critical of young prodigies. It's
| hilarious that we are doing something similar here but this
| time with nuclear weapons insteasd of regular science fair
| fare.
| mannykannot wrote:
| This would not work with plutonium, which is what Philip's
| "Nagasaki-like" (Wikipedia) design apparently used. The gun
| design does not create the critical configuration fast enough
| to prevent it 'fizzling' - the assembly blowing itself apart
| before the chain reaction has progressed far enough for a
| nuclear-scale explosion. Instead, you need an implosion device.
| This is much more challenging, requiring explosive lenses
| (precisely-shaped charges), multiple precisely-timed
| detonators, and an initiator that will produce a burst of
| neutrons just as the explosive's shock waves reach the center
| of the fissile assembly.
|
| I am sure you are right, though, that the bill of materials did
| not include the fissile material.
|
| Anyone surprised by Phillip's result was perhaps assuming that
| it would take something like the Manhattan Project to
| independently design a bomb.
| xhkkffbf wrote:
| >> perhaps assuming that it would take something like the
| Manhattan Project to independently design a bomb.
|
| It's always easier to replicate someone else's work,
| especially when no one knew if it could be done in the first
| place.
| dynm wrote:
| Yeah, probably the most difficult part of the entire process of
| making a bomb is enrichment. The uranium in uranium ore is
| 99.3% (useless) U-238 and only 0.7% (useful) U-235. These are
| chemically identical, so the only thing you have to go on is
| the slight difference in weight, thus the _extremely_ difficult
| methods like centrifuges. (You need to build a giant "cascade"
| of them refining at different levels.) I'd say it's basically
| impossible that he figured out a way to refine uranium for
| $2000.
| throwaway0a5e wrote:
| > I'd say it's basically impossible that he figured out a way
| to refine uranium for $2000.
|
| I'm sure you could get the cost way down if you traded
| throughput/time. Tub grinder vs homeowner wood chipper.
| randcraw wrote:
| According to Phillips' book, his main innovation was designing
| the shaped charges that brought the halves of uranium/plutonium
| together at the right rate.
|
| This he achieved by calling around at Dupont (IIRC) until he
| found someone with the knowledge, which was willingly shared.
| (Presumably this critical info was made inaccessible after the
| paper was graded.)
|
| Freeman Dyson (who worked on the Manhattan Project and later at
| at IAS Princeton) reviewed Phillips' design, confiding to the
| course's professor, "Yes, this should work." Phillips' term
| paper was promptly classified. His only other feedback was to
| receive an A in the course.
| lr1970 wrote:
| > If you just want a bad atomic bomb, isn't it enough to put 2
| chunks of fissile (enough) material at either end of a very
| thick steel tube and shoot them together using explosives?
|
| Linear (gun-type) fission design was tried at Los Alamos in
| early days of Manhattan project and was abandoned in favor of
| spherical implosion device [0].
|
| [0]
| https://en.wikipedia.org/wiki/Nuclear_weapon#Fission_weapons
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