Talk:Cobalt bomb

Censorship?

That an article violates copyright is not a reason to delete the article entirely, but to FIX IT.

It's my experience that editors who just delete wholesale swaths of information on some technical wiki complaint oftentimes aren't so much worried about the technicality, but just don't want the information available at all. Kaz 21:47, 19 September 2005 (UTC)

• Actually, if an article is a copyright violation it is a reason to delete it. --Fastfission 14:05, 24 October 2005 (UTC)

• • I would suggest fix over delete. Deletion should be only the most extreme solution. --Shaddack 12:00, 27 November 2005 (UTC)

language

"it could wipe out millions of people" The term "wipe out" probably wouldn't be found in an encyclopedia. Perhaps "kill" or something similar would be better?

• Replaced with 'slaughter'. Justification:

slaugh·ter (slô'ter) n. 1.The killing of animals especially for food. 2.The killing of a large number of people; a massacre: “I could not give my name to aid the slaughter in this war, fought on both sides for grossly material ends” (Sylvia Pankhurst). DV8 2XL 11:48, 27 November 2005 (UTC)

• • You may maybe consider trying "eliminate". It is less bloody and more Strangelovish. --Shaddack 12:00, 27 November 2005 (UTC)

I picked the term 'slaughter' on purpose. While I am not in any way anti-nuclear in any sense of the word, I won't whitewash the fact that nuclear weapons (particularly of the enhanced radiation sort) are designed to kill as many people as possible in the target area. DV8 2XL 12:06, 27 November 2005 (UTC)

I don't think slaughter is appropriate for killing by radiation. Although it is not defined by that dictionary the implicit meaning is the killing in a violent way, in a bloody way.

Doomsday effect

~~MV~~

In order to make the article better, you could perhaps mention that cobalt bombs would be an extra and lingering danger in the area where they explode, but that however, the amount of cobalt required to cause the effect that Szilard described is enormous and not practical.

+besieged

"originally proposed by physicist Leó Szilárd, who suggested that it would be capable of destroying all life on Earth," is totally without reference (not to mention the idea is preposterous anyway). —Preceding unsigned comment added by Besieged (talk • contribs) 13:29, 1 March 2009 (UTC)

Accuracy

My physics teacher described a Cobalt bomb to us one day. What he describes was not a "dirty bomb" at all but the use of consecutive shells of elements ending in Cobalt. All of these shells would be wrapped around a standard hydrogen bomb. The basic idea is that energy release from one shell would be enough to start fusion in the next element, all the way to Cobalt. I forget the exact amount of energy released, but it would be enough to destroy the Earth.

Nah-- either you misunderstood or your prof is out to lunch. Fusion is hard to produce, and early bombs "coated" even with shells of fusionables, even easy ones like deuterium, didn't fuse it very well (the shell configuration works in supernovas, but you need a star's gravity to help you with the shell compression, so it's not the same thing!). In either stars or bombs, for good fusion you need compression. This is a key idea.

Almost all of the energy available for fusion is already available when making helium, a fact due to the unusually low energy of helium. There's absolutely no point in making a bomb which has higher elements to get energy from fusion, even if they were set up with compression to do it, because burning light deuterium and tritium provides more energy PER GRAM than any other fuel.Sbharris 20:03, 30 May 2006 (UTC)

There actually IS a point to fusion of SOME heavier elements. The boron-11 + proton reaction, while less energetic per gram than thermonuclear fusion, can actually proceed under inertial electrostatic confinement, using equipment orders of magnitude cheaper than thermonuclear fusion. This reaction also has the advantage of not emitting neutrons, so that neutron embrittlement of steel and other reactor structural materials is not the factor it would be in a thermonuclear fusion reactor. Proof of concept has already been furnished in the 1990s by Dr. Robert W. Bussard in the 1990s - a prototype inertial electrostatic confinement reactor small enough to fit on a desktop produced more power than it consumed (something that big-iron thermonuclear fusion reactors have yet to achieve). And finally, boron-11 plus proton emits electrons which can be recovered through the coils of the confinement grid and used as electrical power. I'd say this alone was the "point" in pursuing fusion of elements heavier than hydrogen isotopes.

However, you're right on your refutation of the "physics teacher's" explanation of concentric shells of elements around a thermonuclear device creating subsequent fusion reactions. That's utter nonsense. Intense flux of x-rays or other photons (as in the lasers used in inertially confined thermonuclear fusion reactors) and the presence of a superheated plasma (from the heating of an aerogel foam called FOGBANK around the fusion fuel) trigger nuclear fusion in thermonuclear weapons. These conditions are NOT available outside the nuclear weapon casing loupgarous (talk) 23:19, 15 May 2011 (UTC)

---
'Critics of the cobalt bomb concept point out that the mass needed would still be unreasonably large: 1 gram of 60Co per square kilometer of Earth's surface is 510 tonnes, and fallout does not reach all areas in equal proportions and dispersement (winds, etc.) [2]. While the sheer size and cost of such a weapon makes it unlikely to be built, it is technically possible because there is no maximum size limit for a thermonuclear bomb. However, the effects of nuclear weapons, including blast, physical damage and fallout, do not scale up linearly with weapon size or yield; the magnitude of these effects increases more gradually than the energy released by the nuclear detonation.'

Surely then if you get more bang relatively speaking from a smaller bomb, would making several smaller Cobalt bombs result in needing a smaller overall total mass of bomb? If so, what's the optimal mass for one? You could also reduce the effects of dispersion if you had lots of smaller explosions rather than relying on one big one to explode evenly across the globe.

I don't advocate anyone tries this of course, but surely it's the more logical approach. Arbitrary Logic (talk) 12:04, 3 July 2009 (UTC)

Answering your question, Glasstone and Dolan, in "The Effects of Nuclear Weapons," devote an entire chapter to the deposition of nuclear fallout in which they show that fallout tends to "clump up," not fall uniformly over the area downwind from the blast. Back during the days of frequent atmospheric nuclear testing in the Nevada Test Site, this meant that fallout would often be deposited quite far away from the site of an explosion; the area around New Orleans, Louisiana was one example of a place where fallout tended to concentrate because of the high rainfall there compared to other areas between there and Nevada.

My point is that the 510 tonnes figure is not a maximum amount, but a MINIMUM amount of cobalt required to blanket the Earth with fallout. It assumes perfect dispersion of the Cobalt-60 from the weapon to every corner of the Earth (something highly unlikely in real terms). If one were to use several smaller cobalt bombs as opposed to one huge one (the "one big bomb" concept goes back to before the Teller-Ulam and Sahkarov thermonuclear weapon designs made it possible to have a thermonuclear weapon that was deliverable by aircraft or missiles), one would actually need MORE cobalt to assure that every human habitation on Earth got its share of deadly radiation, because the plumes from the smaller thermonuclear devices would necessarily be narrower, more concentrated and disperse over a smaller area.

By the way, I agree with you that this is NOT something desirable in real terms (world nuclear powers, PLEASE don't try this at home), but logically, if the idea is to deter aggression by holding the human race hostage, one needs to do a complete job of it. That requires MORE cobalt than the floor figure of 510 tonnes - multiples of that figure, I would think.

The scary thing is that a millenialist like Ahmadinejihad or one of his colleagues might seriously seek to hasten the end of days by constructing a cobalt-jacketed nuclear device and detonating it - to threaten to use it in order to beat political concessions out of the rest of the world. The game analogy for nuclear strategy has changed from poker, to the chess of the late Cold War, and may degenerate to a grim variation on "tag" with the accession of Pakistan, North Korea, Iran, Syria and (if intelligence reports are at all accurate) Myanmar and Bangladesh to nuclear weapon power status.loupgarous (talk) 21:16, 14 May 2011 (UTC)

Appearance of cobalt after going through a nuke fireball?

Article states: The fallout of other nuclear weapons has the appearance of sand or ground pumice, which falls back to the ground in short time, and can be filtered by even a handkerchief, unlike cobalt-60 COMMENT: This badly needs needs a ref. How do YOU know what cobalt metal processed through a nuclear fireball would come out physically? A similar oxidized particulate to what the rest of fallout is described as, is MY guess. Sbharris 20:03, 30 May 2006 (UTC)

Chapter IX of The Effects of Nuclear Weapons, "Residual Nuclear Radiation and Fallout," actually does address this issue directly. In the section "Radioactive Contamination from Nuclear Explosion, Land Surface and Subsurface Bursts (9.50)," this chapter describes what fallout looks like: "As the height of burst decreases, earth, dust, and other debris from the earth's surface are taken up into the fireball; an increasing proportion of the fission (and other radioactive) products of the nuclear explosion then condense onto particles of appreciable size. These contaminated particles range in diameter from less than 1 micron to several millimeters; the larger ones begin to fall back to earth even before the radioactive cloud has attained its maximum height, whereas the very smallest ones may remain suspended in the atmosphere for long periods."

There are also photographs and autoradiographs of fallout particles (Figures 9.50 a through 9.50d) in this chapter. So really, the citation already exists in the reference section. All that is required is an appropriate footnote.loupgarous (talk) 15:42, 5 April 2012 (UTC)

Apparently you didn't read my note very well. Just because we know what fallout looks like from a ground burst (silica and various silicate minerals processed through a close-nuclear fireball at millions of degrees) does not mean in the least that we know what cobalt metal looks like after being heated to those temperatures in a fireball. It's not obvious, and the experiment has never been done. Whether it could, or could, not be dealt with in the same manner as silica/silicate-based-fallout I do not believe is known. That is why the statement The fallout of other nuclear weapons has the appearance of sand or ground pumice, which falls back to the ground in short time, and can be filtered by even a handkerchief, unlike cobalt-60 needs a reference. "Unlike cobalt-60" is what needs reference. Cobalt-60 in what form?? We don't know what cobalt metal heated to thermonuclear temperatures looks like. As I said, my guess is aggregate particles of various cobalt oxides, much like you'd get in a lab bottle of one of the cobalt oxides (which I have seen-- the cobalt(II) oxide is green, and the higher oxides like cobalt(III) oxide are black). These are powders than can be an fineness you like; it's not at all obvious that these could not be filtered out like any other oxide powder. In a ground burst the cobalt oxides might be adsorbed and mixed with the silicate oxides and be mixed with them after melting, like silicate-based lava (or pumice) containing oxidized metals. I don't know the answer, but at least I know what I don't know. You don't seem to know what you don't know. SBHarris 17:19, 5 April 2012 (UTC)

You have a good point. Obviously, there aren't going to be any new atmospheric nuclear tests by any of the major nuclear powers; even India, Pakistan and North Korea have been circumspect about containing the fallout from their weapons tests in recent years. What we're considering is something no one's really done - trying purposefully to make as much atmospheric fallout and of as deadly a set of isotopes as possible. We have to proceed from what we know about refractory metallurgy. 500 tonnes of cobalt would be somewhat of a heatsink, so that not all of it would be vaporized to micron-size particles in the fallout from a Szilard-type cobalt device; some of it would fallout as millimeter or larger particles, which (incidentally) would make the cobalt not spread as uniformly or cover as much territory as DevSolar apparently thinks it must. You're absolutely right that we don't really know what the cobalt would fallout as (how much of it would be micron-sized, how much millimeter-sized), and I can't think of any way short of an actual test to find out. I do, in that sense, "know what I don't know." I'm pretty sure NO ONE knows the answer to your question, because the fallout from a test like that would be prolific and people would not only have noticed, but the fatalities from radiation from such a test would have made headlines.

Since we can't cite a reference to the passage you refer to, it ought to be redacted to a statement that CAN be supported by published sources. In fact, that passage no longer exists in the article. I didn't remove it. Did you?loupgarous (talk) 19:01, 5 April 2012 (UTC)

Not that I remember. May be been somebody else who read this discussion 6 years ago. But I cannot remember many of my edits from 6 years ago, so no guarantees. SBHarris 21:12, 5 April 2012 (UTC)

Merge to Salted Bomb

I think that this article should be merged with the Salted bomb article. This is on a subset of that article, and doesn't really need its own page. --Apyule 14:56, 19 June 2006 (UTC)

Use In Science Fiction - The second Planet Of The Apes Film featured a doomsday weapon that was said to have a Cobolt caseing.

Merged?

It appears that Salted bomb article doesn't exist anymore. Just wonderful. All info about non-cobalt (gold, zinc) bombs is deleted... —The preceding unsigned comment was added by 195.212.29.187 (talk) 10:59, 6 February 2007 (UTC).

This page should have been merged into the Salted Bomb article rather than vice versa. 131.111.103.224

I respectfully disagree. Most people enter memes as search terms. "Cobalt bomb" is a much more prevalent such meme than "Salted bomb." So from a viewpoint of "what serves most Wikipedia users best," I submit more of them will be searching for the term "Cobalt bomb" than "Salted bomb," since there is practically no popular literature reference to "salted bombs" by that name. Herman Kahn and Leo Szilard, among others, made "cobalt bomb" a very well-recognized concept and our users will encounter it in movies, television (for example, one episode of Star Trek: the original series makes direct reference to it), novels and other literature. It only makes sense to give them what they'll likely be looking for.loupgarous (talk) 03:26, 7 November 2011 (UTC)

some version saved @: http://web.archive.org/web/*/http://en.wikipedia.org/wiki/Salted_bomb 74.12.96.200 06:53, 27 July 2007 (UTC)

Thanks for giving us that link.loupgarous (talk) 03:26, 7 November 2011 (UTC)

Undefined

Exactly how much is an "exceedingly large and impractical" amount? -- Noclevername 23:50, 20 February 2007 (UTC)

510 tonnes of cobalt (the amount calculated to be required to make one gram of cobalt-60 and its decay daughters available on the average for every square kilometer of the Earth's surface) is one-tenth the current annual production of that element in the Russian Federation (as an example). Diversion of that much cobalt for use in a single weapon would be economically crippling to any major commercial producer of the metal. So, to answer your question, the amount of cobalt calculated to be required to produce an actual "Doomsday device" in the form of a cobalt-jacketed thermonuclear weapon is also "an exceedingly large and impractical amount."

The problem is compounded by the irregular nature of nuclear fallout deposition; one cobalt bomb would, in practice, not suffice to sterilize the Earth of human life because its fallout would not reliably reach every corner of the Earth. Kahn and other theorists had proposed that a nation in deadly earnest (no pun intended) to use the cobalt bomb as a deterrent would be constrained to build several such devices, placing some of them in ocean-going freighters in order to have world-wide coverage of the Earth's surface with deadly radioactivity.loupgarous (talk) 20:49, 14 May 2011 (UTC)

Salted Bomb ?

What is a salted bomb ? It's not explained here. —The preceding unsigned comment was added by 87.65.138.108 (talk) 20:00, 5 May 2007 (UTC).

It's the general type of bomb where elements are added to contribute to the fallout. Cobalt bombs are but one example; other examples would be zinc, gold, or tantalum bombs. Unfortunately, salted bomb redirects to cobalt bomb, which doesn't make this clear. Xihr 20:04, 5 May 2007 (UTC)

Revert merge ?

I think the merge needs to be reverted (is this possible, I cant find much information on reverting merges) and the cobalt bomb article made a part of the salted bomb article as was stated earlier. Edd17 20:32, 29 June 2007 (UTC)

Or the salted bomb article could be recreated and then this article could be merged into it. Edd17 20:45, 29 June 2007 (UTC)

The most sensible solution would be to rename Cobalt bomb to Salted bomb, keeping the #REDIRECT there. Cobalt bomb is the most commonly discussed type of salted bomb, so it should also mention the other commonly-discussed types of salted bombs (e.g., zinc, gold). The general concept is of a salted bomb; a cobalt bomb is just one instance. Xihr 01:46, 1 July 2007 (UTC)

So this article would be named Salted Bomb and Cobalt Bomb would redirect here? some of the text would need to be altered and the information on other types of bomb found as well (particularly the table). Edd17 20:14, 1 July 2007 (UTC)

Salted bomb and Cobalt bomb, yes. The bomb word shouldn't be capitalized, since it's not a proper name. Xihr 20:27, 1 July 2007 (UTC)

Citation Needed

It appears that the statement mentioned here needs a fact check:

http://en.wikipedia.org/enwiki/w/index.php?title=Cobalt_bomb&diff=250458634&oldid=250274935

I'm not sure about it. Perhaps somebody knowledgeable about the topic and having lots of sources can go at it? Cornince (talk) 02:09, 9 November 2008 (UTC)

Australian peace activist and atmospheric scientist Brian Martin, in "The global health effects of nuclear war," Current Affairs Bulletin, Vol. 59, No. 7, December 1982, pp. 14-26. http://www.uow.edu.au/arts/sts/bmartin/pubs/82cab/#n1 has covered this issue indirectly in the section of his paper "Overkill," in which he describes the fallacy of linear extrapolation of nuclear weapons effects to the world population at large succinctly. Earlier in the paper (the section "Fallout") Dr. Martin distinguishes between the sorts of fallout produced by differing sorts of nuclear detonations in terms of the dose of fallout delivered to nearby and worldwide populations.

The matter is covered in much more detail, but with similar conclusions to Dr. Martin's, in The Effects of Nuclear Weapons, Samuel Glasstone and Philip J. Dolan (editors), United States Department of Defense and Department of Energy, Washington, D.C., http://www.fourmilab.ch/etexts/www/effects/, considered the definitive technical work on the subject of nuclear weapons effects.

Their chapter on nuclear fallout http://www.alternatewars.com/WW3/WW3_Documents/Weapon_Effects/Effects_1977_09.pdf discusses in great detail the highly irregular deposition of fallout on the surface of the Earth after nuclear detonations. --vfrickey (talk) 05:43, 30 November 2008 (UTC)

I have placed citations supporting these criticisms of the "overkill" and "doomsday machine" concepts in the text of the article. loupgarous 19:51, 5 April 2009 (UTC)

The effects9.pdf is offline, we should replace it with another web links. `a5b (talk) 21:54, 26 May 2011 (UTC)

sorry it took me so long to get back on this, I did find an alternate link for Chapter 9 of Glasstone and Dolan, "The Effects of Nuclear Weapons" and have altered the text.loupgarous (talk) 23:05, 6 November 2011 (UTC)

Cobalt bomb test

"The British did test a bomb that incorporated cobalt as an experimental radiochemical tracer (Antler/Round 1, 14 September 1957). This 1 kt device was exploded at the Tadje site, Maralinga range, Australia. The experiment was regarded as a failure and not repeated." http://nuclearweaponarchive.org/Nwfaq/Nfaq1.html#nfaq1.6 —Preceding unsigned comment added by 212.76.37.154 (talk) 01:08, 25 February 2009 (UTC)

This heading's potentially misleading. Antler/Round 1 was not a test of a "Cobalt bomb" as we have defined it in our discussion.

According to the Nuclear Weapons Archive [1], Antler/Round 1 was a "Test of Pixie, a lightweight small diameter implosion system with a plutonium core. This test later became notorious because of the experimental use of cobalt metal pellets as a test diagnostic for measuring yield (presumably by estimating the neutron flux from the degree of activation of the target pellet). Discovery of (mildly) radioactive cobalt pellets around the test site later gave rise to rumors that the British had been developing a "cobalt bomb" radiological weapon."

The Pixie system was a pure fission device and not even close to the sort of intense neutron source required to transmute significant quantities of cobalt-59 into the intensely radioactive cobalt-60. It does not qualify remotely as a "cobalt bomb" for our purposes - it just had cobalt pellets in it to allow scientists to measure how much of the cobalt in them had been neutron-activated, thus giving an indirect indication of neutron flux from the detonation of the weapon and some indication of how efficient the implosion system was in 'burning' the plutonium core of the weapon loupgarous (talk) 03:42, 7 November 2011 (UTC)

"critics" of the bomb?

"Critics" of the bomb say it won't destroy all life on the planet? Seriously? Do they see the destruction of all life as a desirable goal? Serendi^podous 09:18, 31 July 2010 (UTC)

Changed it. Serendi^podous 09:21, 31 July 2010 (UTC)

Brian Martin

present version cites Brian Martin. It seems to me though that the Martin article does not discuss the cobalt bomb, only "ordinary" nuclear bombs. — fnielsen (talk) 22:19, 30 January 2011 (UTC)

There is no difference in the behavior of particulate matter from the fallout plume of a cobalt bomb compared to that from a more conventional nuclear weapon. If your grounds for removing my reference to Dr. Martin's paper were his failure to mention salted nuclear weapons specifically, than you have made a destructive change to the article by removing reference to a major flaw of the cobalt bomb concept, the fact that nuclear fallout does not fall uniformly, but according to how the particles in the fallout are deposited by precipitation and other climate factors. As Dr. Martin is a climatologist, he was speaking from expertise in his own field.loupgarous (talk) 11:12, 14 May 2011 (UTC)

Gold-197

The article cites the radioactive nuclide present in gold bombs as ¹⁹⁷Au, which in fact is the only stable isotope of gold (curiously nobody discovered that mistake over so many years). It seems to me that ¹⁹⁵Au with a half-life of 186 days is probably what the original author meant. Zhieaanm (talk) 12:13, 16 February 2011 (UTC)

Gold-198, not gold-197, is mentioned in the article as the end-product of a hypothetical "gold bomb." In the chapter of the High Energy Weapons Archive cited in the references, Carey Sublette specifically mentions that gold-197, which is the 100% naturally-abundant stable isotope of gold, would be transmuted into gold-198 (t 1/2=2.697 days) by the capture of a neutron from the nuclear device in a hypothetical "gold bomb."

Consulting the Chart of the Nuclides, there's no stable or even acceptably long-lived precursor to gold-195 which could be used to jacket a nuclear device. Gold-195 is the decay chain daughter of mercury-195, which has a half-life of 9.9 hours; the decay chain precursors of mercury-195 are even shorter-lived, as far back as you care to go. There's no way to get gold-195 out of a salted nuclear weapon.loupgarous (talk) 12:05, 14 May 2011 (UTC)

Possible source=

I recommend this (pages 290-292) as the source for the article- it's evaluation of Szilard claims....

http://books.google.pl/books?id=_Q0AAAAAMBAJ&pg=PA290&lpg=PA290&dq=Hydrogen-Cobalt+Bomb+in+bullletin+arnold&source=bl&ots=_W7CkxJQRk&sig=MWKbUTyq3tOIbM7H5kaVcBsEMBU&hl=pl&ei=ofG5TbG_C4ODOruypP0O&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBkQ6AEwAA#v=onepage&q&f=false —Preceding unsigned comment added by 193.25.0.13 (talk) 11:19, 29 April 2011 (UTC)

Isn't this 510-ton number a bit ridiculous?

I don't really understand why people keep coming back to this "510 tons" number. That's a mind experiment only: "How much cobalt would I need to bring 1 gram of cobalt to every square km of earth's surface?". What Szilárd was talking about when he thought up the cobalt bomb is that it would also kill the people in the target area who survived the initial blast. From a human standpoint, you only "need" to irradiate the arable land, which is only a fraction of the 30% of earth's surface that actually are land. And suddenly, you'll see that the ability to destroy all human life on earth is within the reach of an "arsenal of cobalt bombs".

Not that we need cobalt bombs (or any other "big bang" stuff) for that. We're doing a fine job exhausting natural resources and poisoning the ground just by negligence. To quote T.S. Eliot, the world will end with a whimper, not a bang. -- DevSolar (talk) 09:23, 10 June 2011 (UTC)

The figure is preceded by the phrase, "To provide a point of reference," so it's clear that the figure quoted is not intended to be taken literally, but rather as a measure of scale.

As for your other comments, Wikipedia talk pages are for the discussion of improvement of the actual article, not political soapboxes that have nothing to do with the subject of the article.  Xihr  03:24, 13 June 2011 (UTC)

OK, scrap that personal comment of mine, that indeed was unnecessary. But I feel that this "point of reference" is an attempt to ridicule the whole concept of a "salted bomb", which is IMHO not NPOV. -- DevSolar (talk) 06:59, 20 June 2011 (UTC)

The 510 tonne number came to Szilard before the Teller-Ulam design made thermonuclear weapons deliverable. The first thermonuclear device was not only not deliverable, it pretty much filled a building at the test site. So Szilard was thinking in terms of militarizing the new weapon SOMEHOW. And at the time, what amounts to global radiological blackmail was the only option - the one thing the huge, undeliverable weapon COULD do is make neutrons, so Szilard came up with a way to make it a game-changer - by making enough Cobalt-60 to sterilize the Earth of human life.

However, to hit the all the arable land with a single Cobalt Bomb, you HAVE to cover the rest of the globe, too - you just have the one weapon and need to blanket the globe with it. However, 510 tonnes is still a reasonable aggregate number for the amount of cobalt-59 required to jacket either a single massive thermonuclear weapon with a yield in the multiple hundred-megaton range, or many smaller weapons - EACH of which must still be jacketed by enough cobalt (many tonnes) to cover their assigned downwind regions - that deployment by freighter seems the practical method of placing them where they must be in order to kill their assigned populations. You're still talking about a tenth of the annual production of cobalt of the Russian Federation. A megalomaniac, or perhaps a Millenialist like Ahmadinejihad who is presumably seeking to hasten the End of Days by mass destruction might still pursue such a course with one or more cobalt bombs, each filling a freighter, detonated off the US West Coast where prevailing winds would carry the cobalt over the continental US.

It would make more sense, though, to just blanket North America with EMP from one or more nuclear weapons detonated in the ionosphere in such a way that the pulse propagates through our electrical grid and destroys every semiconductor in the US and Canada. That alone would irreparably destroy our national infrastructure and cause massive economic and social chaos, and according to some calculations, the deaths of two-thirds of the US populace from starvation, disease and civil violence. And it would be incomparably cheaper to do this than to attempt the Cobalt Bomb.loupgarous (talk) 01:19, 7 November 2011 (UTC)

I don't understand, really, why people keep coming up with strange examples, but don't add up the number and spread this BS about bombs "filling a freighter"...? Again, let's start at the 510-ton-for-the-whole-earth. OK, so that's 1/10 of the annual production of Russia. Unlikely, I grant you that, but nowhere near impossible. But you don't need 510 tons of cobalt to build one bad sucker of a salted bomb! Basic math. Area of the U.S.A.? 9.8 million square kilometers. That's less than 1/50th of the earth surface. 1/50th of 510 tons is around 10 tons, or 1/500th of the anual production of Russia. That fits on a lorry trailer, for sterilizing all of the U.S.A.. You'd need much less than that to irradiate the whole Boston-New York-Washington area - a bomb that fits on a pickup. At that scale, the whole bla-bla about unequal distribution of the fallout or nonlinear scaling of effect is debunked for what it is: Completely missing the point. Building a cobalt bomb is not about "sterilizing the earth", it's about giving a comparatively small nuclear weapon very severe and long-lasting effects far exceeding the actual yield. -- DevSolar (talk) 12:37, 16 December 2011 (UTC)

You've never seen a fallout plume map, have you, DevSolar? I have. The Effects of Nuclear Weapons (the pertinent chapter, "Residual Nuclear Radiation and Fallout," is accessible as a .pdf in the reference list in this article) shows that fallout is not deposited evenly downwind from a nuclear weapons. So my point remains valid - if the point of the exercise is Szilard's original thesis - a weapons system which is capable of destroying all life on the planet Earth (which I agree with previous posters is a "thought experiment" more than a valid specification for a weapons system), then you have to make enough cobalt-60 to cover the habitable Earth (not just the "arable Earth," as you say). Many smaller cobalt bombs would use roughly the same amount of cobalt as the one large weapon. In terms of a practical weapons system, the multi-megaton weapons the Soviets (and their Russian successors) developed to destroy ICBMs in their silos did much of what you posit smaller cobalt bombs would have done as radiological weapons, for they would have landed in the midwest regions of the US with massive ground bursts, creating huge swaths of radioactivity downwind and killing thousands and hundreds of thousands in unprotected areas. The difference would be that this radioactivity is sufficiently short-lived that persons behind thick enough walls for a period between two weeks to a month would be able to step back out into survivably low radiation fields. But I concede your point - partly- a semi-trailer could, conceivably, carry a thermonuclear device jacketed with enough cobalt to create a plume of cobalt-60 downwind and make some of the area downwind pretty much permanently lethal. But as a close reading of the chapter of The Effects of Nuclear Weapons we've cited as a reference in this article shows, the area contaminated would not be uniformly contaminated - not a big continuous block of contaminated land, but a blotchy stretch of land with many areas free of contamination or lightly contaminated. To completely depopulate even the metropolitan areas you mention would require MANY, MANY smaller cobalt bombs with overlapping fallout plumes. To systematically depopulate the Earth WOULD require an aggregate amount of cobalt for weapon jackets not much less than Szilard's estimate. Perhaps more.loupgarous (talk) 15:10, 5 April 2012 (UTC)

510 tons, revisited.

Consider: "Leó Szilárd [...] suggested that an arsenal of cobalt bombs would be capable of destroying all human life on Earth." (Emphasis mine to point out plural.) The next two paragraphs go on blurbing about a single (singular) bomb, about how the effects wouldn't "scale".

I repeat my accusation: That's not "providing a point of reference", that's smoke and mirrors. I suggest removing the two paragraphs in question, and - if necessary or desirable - replace it with some technical information on how much irradiation would result from a bomb of so-and-so much yield and so-and-so much cobalt and what the effects would be. But this "510 tons" blurb is simply misleading. -- DevSolar (talk) 11:45, 16 February 2012 (UTC)

That's why we have cited The Effects of Nuclear Weapons, chapter IX, "Residual Nuclear Radiation and Fallout," in the references section - it contains the necessary conceptual information to allow readers to estimate the requirements for blanketing the inhabitable Earth with nuclear radiation. I recommend you read the chapter in its entirety before persisting in your objections to the 510-ton figure for the amount of cobalt needed to do that job. Otherwise, you're overlooking facts and holding fast to your own opinions on this issue.loupgarous (talk) 15:15, 5 April 2012 (UTC)

Blissfully ignoring the whole previous section. The "510 ton" number was calculated from the assumption that one would have to blanket the entire planet with fallout from a single bomb. I don't even challenge the calculation, but the number it results in is not about the subject of the article, nor what Szilárd talked about. "Cobalt bomb" != "doomsday device". That number is a fallacy, and does nothing for the article. -- DevSolar (talk) 13:06, 25 May 2012 (UTC)

H-bomb times 1000 !?

I've once red that a hydrogen bomb covered with a cobalt shield would make the bomb up to a 1000 times more powerful, but not more radioactive thow. I think the source was "Guiness World Records" (swedish edition) 1974 or 1975. Boeing720 (talk) 19:24, 5 July 2012 (UTC)

I think the article and the cited references make it quite clear that you either misunderstood, or simply reinforcing that "Guiness World Records" might not be the best source for physics. -- DevSolar (talk) 12:18, 31 July 2012 (UTC)