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Talk:Boosted fission weapon

Use in Implosion Weapons
As I understand it, the usual configuration of a tritium boosted weapon is that deuterium (D) and tritium (T) are placed in the centre of the pit (ie the core of plutonium or highly enriched unranium) of an implosion-type weapon. The shockwave of the implosion passes into the pit and produces a very high temperature in the centre sufficient to ignite thermonuclear fusion in the DT mix. The fusion reactions give off a burst of neutrons which initiate the fission chain reaction more quickly than would spontaneous fission alone. This increases the amount of fission that can occur in the brief time before the pit blows itself apart. The thermonuclear yield is insignificant, but the yield of the fission reaction is greatly increased.Man with two legs 14:12, 11 October 2005 (UTC)

I believe it takes not just the implosion energy from conventional explosives, but fission energy from the early stages of the fission chain reaction, to start fusion. After this, both fission and fusion proceed, the fission assisting the fusion by continuing heating and compression, and the fusion assisting the fission by radiating fast neutrons. As the fission fuel depletes and also explodes outward, it falls below the density needed to stay critical by itself, but the fusion neutrons keep fission going for longer than it would otherwise.

Besides increased yield (for the same amount of fission fuel with vs. without boosting) and the possibility of variable yield (by varying the amount of fusion fuel), possibly even more important advantages are allowing the weapon (or primary of a weapon) to have a smaller amount of fission fuel (reducing the risk of predetonation) and more relaxed requirements for implosion.

Also, I believe all boosting of primaries is done with gas, not 6LiD, probably because the latter is not a net producer of neutrons, and would not provide the quick neutron boost that DT fusion does. --JWB (talk) 07:19, 22 November 2007 (UTC)

 * Both have been used. See Operation Grapple.  I'll expand on this when I have time.Man with two legs (talk) 09:21, 22 November 2007 (UTC)

 * It's been used in tests, but did it ever make it to production weapons?--JWB (talk) 04:26, 24 November 2007 (UTC)
 * Dunno. But if you look here:  you will see a diagram of the American mk28 H-bomb which crops up on the internet from time to time.  It is not at all certain that the details are right, but you can see it uses both kinds of fusion boosting.  Why this design also uses an external neutron generator is something I have not made sense of (though remember this drawing is not reliable).

 * My guess is that tritium gas is used to initiate the explosion by giving a burst of neutrons when the imploding shock wave reaches the centre, and Li-6/D is used to improve immunity because it is a neutron absorber when cold and a way of turning neutrons into high energy neutrons when hot. I have never seen a source for this, which is why I did not put that in the article.  It occurs to me that tritium gas could work in both modes.

 * Rather frustratingly, I cannot find my source for the bit about shock waves. I remember that it pointed out that a converging shockwave produces a theoretically infinite temperature.  In practice, you merely get a very high temperature but because at any time some atoms have more than the average energy, a small proportion (a few million) can fuse.  Of course, that source might have been wrong.  I also remember seeing a description of this reaction: T+T -- > He-4 + 2n suggesting that pure tritium can be used and not a DT mix.

 * In Britain and the H-bomb around p.189 there is mention of tritium and no mention of deuterium use in the Burgee shot. In Dark Sun p.501-3 it describes putting tritium (it loudly does not say D-T) in the sparkplug of Ivy Mike. These two support the use of pure tritium.  The use of 'a very small amount' in Mike (where an awful lot of other fusion was about to happen and weight was not an issue) suggest to me that the shockwave bit is correct because the neutron contribution from the tritium would be insignificant by the time the sparkplug had become hot enough to cause fusion.
 * Man with two legs (talk) 12:01, 24 November 2007 (UTC)
 * Boosting is explained quantitatively on page 563 of A Technical History of America's Nuclear Weapons by Dr Peter Goetz. His example uses 12 grams of a 3:2 D+T mixture biased in favor of Tritium, which kindles after 0.1 kT to 0.3 kT of fission yield.

 * The boost gas cannot kindle from chemical implosion alone, which typically compresses the gas to "50 to 100 times the density of solid DT", or roughly 11 to 22 g/cm3. The example in the book has the DT gas starting in a high-pressure canister at 5000 bar, which is a density of roughly 1 g/cm3, so that's maybe 20:1 compression. Or even if the gas expands 5:1 during injection, it's still only 100:1 compression. This is a large compression ratio compared to the, at most, 2.5:1 compression of the Plutonium, but is orders of magnitude insufficient to reach the 20,000,000K needed to kindle rapid fusion. Adiabatic compression puts the DT gas in the ballpark of only 1000K; the initial temp may be higher, and there may be shock heating and other effects, but none of these could plausibly close such a large gap. Another argument is that were it possible for chemical explosives alone to trigger fusion, then pure-fusion bombs would be possible, and being desirable, would certainly have been developed, yet despite the best efforts of many weapons labs, none have ever achieved fusion w/o the aid of fission (or building-sized banks of lasers). In fact, avoiding early heating of the DT gas is actually desirable, as it allows for a higher final density. Final density is limited by implosive pressure, which is on the order of 50 GPa (500,000 bar).

 * The boost gas compresses faster than Rayleigh-taylor instability can mix the DT gas with the Plutonium. On page 564, the boost estimates that R-T instability takes ~100 nanoseconds, versus only a few nanoseconds for kindling fusion, although this estimate seems to exclude the fractional microsecond taken for implosive compression.

 * Once the boost gas kindles, the fusion rate accelerates catastrophically, and the entire burn finishes within "a few nanoseconds", which is less than one neutron generation. One intuition for this is that the DT gas was already being heated to fusion temperature by the fission process, which is only accelerating, and thus, any additional heating provided from the fusion reactions would tend to further elevate the temperature, vastly increasing the reaction rate (temperature dependence is highly non-linear). The book provides an example of 12 grams of DT gas, producing enough 14.1 MeV neutrons to fission 576 grams of Pu239 (~10 kT). Then, due to the higher speed of the fusion neutrons, the number of neutrons released per fission event jumps from 2.9 to 4.6, providing enough neutrons to fission 2649 grams of Plutonium in the next generation. It further states that real-world yields of 80% to 90% efficiency are possible from a boosted ~3 kg Plutonium pit. The fusion reaction takes "a few nanoseconds", the fast neutron generation takes <10 ns, and the subsequent generation takes ~10 ns, so this suggests that boosting can drive the fission reaction from <0.5% (<0.3 kT) to >80% (>48 kT) in barely more than 20 ns. For comparison, neutron doubling in even an infinitely supercritical compressed mass of Pu239 could only grow by 2.9X per ~10 ns neutron generation, requiring ~50ns for 200:1 scaling. The book cites "40 to 50 nanoseconds" as the interval between the onset of expansion and the core becoming subcritical. In an unboosted core, the maximum efficiency is limited by the exhaustion of fissile material and the creation of neutron absorbing fission products, both of which reduce criticality, slowing reaction growth, and also by the expansion of the core outpacing the slower reaction growth. The book cites 35% as typical yield for a well-designed unboosted core, and 50% as the ceiling available for heroic efforts such as the Ivy King shot. Versus 80% to 90% for a smaller 3kg core with less compression, but with boosting. Such a core might only produce 0.3 to 1 kT w/o boost-gas insertion, as is demonstrated by many dial-a-yield designs, implying an unboosted yield of only a few percent efficiency. In such a precisely engineered "barely sufficient" design, insertion of the boost gas is an order-of-magnitude yield increase. Alternatively, boosting provided roughly 2X yield increases over contemporary unboosted designs that were intended to be as efficient as feasible.

 * The book I am citing provides good insights, but must be taken with a grain of salt as it clearly contains a few unit conversion errors, and possibly other more serious inaccuracies. For example, on pg 564, the book implausibly quotes the DT gas as being compressed to 7 kg/m3, which is only 0.007 g/cm3, substantially less than its original density at 5000 bar! I believe this to be a mistake of using the wrong units (perhaps 7 g/cm3 was intended?) as the following sentence says "50 to 100 times the density of solid DT", and solid DT has a density of 0.21 g/cm3. A similar mistake of units happens on page 28, where the book says that implosion reaches "500,000 kilobars, or 500,000 times the pressure at [E]arth's surface". Clearly, the book meant 500 kilobars, not 500,000, as that's 50 GPa, which is comparable to both explosive pressures and the bulk modulus of Plutonium; the larger figure is vastly too optimistic. My confidence in the rough accuracy of the figures that I'm quoting comes from extensively comparing figures from different chapters with each other, and sanity checking them in the equations.

 * [User: DDopson] — Preceding unsigned comment added by Ddopson (talk • contribs) 18:56, 8 November 2023 (UTC)

The Nuclear Weapons Archive you gave discusses fusion via chemical explosive implosion farther down the page and says it's not practical.
 * You haven't got it: the amount of fusion I am talking about from the dead centre of the shock wave is tiny and is for initiating the fission reaction. Not at all the same thing as the hypothetical fission free bomb. Man with two legs (talk) 10:59, 25 November 2007 (UTC)

The external neutron generator is the initiator.
 * I know. The thing that puzzles me is the need for one of those and tritium gas at the same time because I have reason to believe that the gas itself can be used as the initiator, which is the main point that needs nailing down here. Man with two legs (talk) 10:59, 25 November 2007 (UTC)
 * The presence of an external initiator strongly suggests that the boosting gas at the center is not acting as the initiator. I've seen somewhere saying that it doesn't work, but don't have the reference handy at the moment. --JWB (talk) 16:56, 25 November 2007 (UTC)
 * I agree that is evidence against the shockwave thing. I finally found a reference for it at nuclearweaponarchive.org (in a section which is puzzlingly hard to find on Google) where it says:

A somewhat similar approach is to use the implosion to initiate a neutron generating fusion reactions with tritium and deuterium (described in Section 2.2 below). It may seem surprising that this can be made to work, given the well known fact that fission explosions are required to produce the temperatures that fusion reactions normally need. Three considerations overcome this obstacle. First, an exceedingly low rate of fusion is actually required. One neutron (and thus one fusion) every 10 nanoseconds is sufficient, a rate that is only some 10^-24 as fast as an actual fusion explosion would need. Second, implosions focus energy and can reach very high temperatures near the center. Theoretically the temperature at the center is infinitely high, but lack of perfect symmetry reduces this. Even so, a high precision implosion can reach temperatures of several hundred thousand degrees C. Third, the velocity of atoms in a gas or plasma is a statistical (Maxwellian) distribution. A very small portion of the atoms can greatly exceed the average energy. Thus enough atoms in the D-T mixture near the center can reach fusion energies to produce the required rate of neutron production. This type of implosion initiator is even more difficult to engineer than the Be/Po-210 type since the very high precision implosion is required to achieve the required symmetry. The major advantage is that the short half-life Po-210 is not needed.
 * However, that seems to contradict other things in the same (reasonably reliable) site. Also, Georgewilliamherbert says below that he has not heard of this working, and the signs are that he has looked into this quite a lot.  By the way, according to Dark Sun only about six neutrons were produced by the urchin in the primary of Ivy Mike so a tiny number of fusions really would be enough: 3g of tritium is 6E23 atoms so a 1 in 1E23 rate of fusion would be enough to match the urchin.
 * Most telling is that every modern weapon design we have component details on includes some sort of neutron generator, in all the recent ones an external pulse neutron generator tube array. Georgewilliamherbert (talk) 00:56, 29 November 2007 (UTC)
 * With the implosion fusion method, initiation would be very sensitive to the schedule (is peak energy in the boost gas at exactly the same time as maximum density of the fissile material?) and symmetry of the implosion, and it would be difficult to control timing precisely and reliably. The pulse tube seems to offer precise timing control. Also, the NWA quote doesn't actually say implosion fusion initiation was used in any bomb tests. And, even if it were used in a test, it might be hard to tell if it worked or not, given that Pu-240 has a high spontaneous fission rate. --JWB (talk) 08:38, 29 November 2007 (UTC)

T-T fusion is listed at Nuclear fusion. It produces less total energy (11.3 MeV) than D-T fusion (17.6 MeV), and the energy is split between one alpha particle and two neutrons. D-T fusion has only two products, and conservation of momentum forces the neutron to exit at 4 times the speed that the alpha does, I think 17% of speed of light, which makes the neutron carry 4/5 of the fusion energy. These extremely fast and energetic neutrons spread the fission chain reaction faster, and produce fissions that themselves release larger number of neutrons. T-T fusion will produce less energetic neutrons. The initiation temperature or temperature-reaction curve for T-T is not given but may be higher than D-T. Given that deuterium is much cheaper, and can be handled in the same way as tritium, there is little reason not to include deuterium with tritium.
 * Thanks for that detail of the reaction.
 * My point was that both sources strongly suggest tritium was being used alone. Man with two legs (talk) 10:59, 25 November 2007 (UTC)
 * I have a hard time believing tritium would be used alone in any actual weapon (as opposed to physics measurements in a test device) and hope you will include the actual quotes for readers to evaluate. In a discussion of tritium vs. lithium boosting, it's possible the deuterium was not mentioned because it's present in both boosting methods and therefore not an issue worth mentioning each time. --JWB (talk) 16:56, 25 November 2007 (UTC)

Ivy Mike's secondary was mostly deuterium, so there was certainly deuterium present. It is hard to say what the tritium was intended for with out more information. The tritium would reach higher thermal velocities than uranium or fission products because it is lighter, so some may have been ejected into the surrounding deuterium at high speed, where it might fuse and supply heat and neutrons. Or, since the test was an experiment, it may have been included simply to facilitate some measurements. Anyway, a secondary is a very different case than a primary, and is not what is meant by "boosted fission weapon".
 * The tritium was a "quite a small amount" (Dark Sun, p. 501) inside the spark plug (the fission component in the centre of the deuterium container) where its only possible purpose would have been to boost the fission therein. There is no chance it could have got near the deuterium (if they had wanted them to mix, they would simply have put them in the same place).  It was certainly some kind of fusion boosting of fission in the spark plug, but we are back to the same question: was it the high temperature of the fission reaction or the high temperature in the centre of the converging shockwave that initiated fusion in that tritium? In short, we need a source. Man with two legs (talk) 10:59, 25 November 2007 (UTC)
 * Was it in a separate compartment inside the sparkplug, or diffused in as hydride? I'm not sure how much this has to do with the boosted fission weapon (the title of this article) case. Implosion of a primary fission pit is carefully engineered to make the most of the relatively weak chemical implosion, while radiation implosion is much more powerful. And in the secondary case, there are already lots of neutrons floating around from the primary explosion, so initiation is not a question. --JWB (talk) 16:56, 25 November 2007 (UTC)
 * It was in a cavity in the sparkplug. "To make things more certain, push them further in a favorable direction" so it looks likely that the bomb would have worked without it.  Just why the zillions of thermalised neutrons from the primary were not considered enough is not clear.  But it is also true that making an H-bomb work is very hard to do, presumably for reasons that are not publicly known. Man with two legs (talk) 23:14, 28 November 2007 (UTC)
 * This was the very first thermonuclear test, so they were not even sure what was needed to make an H-bomb work! If the tritium was contributing anything in particular, its contribution was more likely to be adding to the sparkplug's heating at the right time, than initiation neutrons. --JWB (talk) 08:45, 29 November 2007 (UTC)

Also, the radiation implosion of the secondary is supposed to avoid heating the fusion fuel too much, because that would interfere with the goal of maximum compression. Once maximum compression is reached, then you want to quickly raise the temperature to initiate fusion.
 * Not clear what point you are making. BTW, I did know that. Man with two legs (talk) 10:59, 25 November 2007 (UTC)

Too much neutron-absorbing 6Li in the center of a primary would raise the critical mass of plutonium needed for criticality, which would detract from boosting's reduction of the plutonium requirement to reduce predetonation insensitivity. --JWB (talk) 04:13, 25 November 2007 (UTC)
 * Reducing plutonium is not a way to create radiological immunity, although it does seem to help. Immunity was a problem with the British 1/2 megaton atom bombs which seem to have used no plutonium at all.  I am certain that fusion boosting was the cure for this problem because that is specifially stated in Britain and the H-Bomb p. 177 on, but I have no source for the mechanism (that book is reliable but it concentrates on the tests rather than technical details). Man with two legs (talk) 10:59, 25 November 2007 (UTC)
 * Sorry, I meant reducing the weight of fissile material in the pit, whether that is Pu or enriched uranium. The huge fission bomb had something like 4 critical masses, so reducing the fissile material below 1 critical mass by boosting was not an option. And looking at p. 177 on Google Books, I see no mention of the huge fission bomb; it only says that plutonium cores are more susceptible, and at the bottom of the page, that reducing the quantity of fissile is the way that boosting helps. Could you give a more specific reference for boosting of the 1/2 megaton bomb itself? --JWB (talk) 16:56, 25 November 2007 (UTC)
 * If you re-read it you will see it doesn't quite say those things. That is a problem with that book: you have to read it like a lawyer to extract the technical information from the story.
 * The big A-bombs (later estimated at only 0.4MT) were not boosted and not immune. They just used large amounts of uranium and nobody told the Russians they were vulnerable.  They were also staggeringly unsafe. Man with two legs (talk) 23:14, 28 November 2007 (UTC)

This discussion is wandering around too much. Here some facts I have nailed down with 99%-100% certainty:
 * 1) Both tritium gas and solid LiD fusion boosting have been demonstrated
 * 2) Fusion boosting is essential for radiological immunity in efficient fission bombs
 * 3) Tritium (not D-T) fusion boosting was used in the secondary of Ivy Mike separately from the large scale fusion of deuterium
 * 4) The amounts of tritium used in fusion boosting are of the order a few grams

One that is taken seriously but may be wrong:
 * 1) The mk28 H-bomb used both kinds of boosting

And here is one I did not make up but which needs sourcing or rebutting:
 * 1) The converging shockwave of an implosion device creates a high enough temperature in the exact centre to cause a very small amount of fusion in pure tritium

An example of converging waves producing remarkably high temperatures appears in Sonoluminescence.

Man with two legs (talk) 10:59, 25 November 2007 (UTC)

I have posted a question on this at User_talk:Georgewilliamherbert. He knows something about this and may be able to shed light on it. Man with two legs (talk) 16:09, 25 November 2007 (UTC)

 * I would like the article not just to try to document all techniques that have ever been used, but to state which are used in modern weapon designs. Designs like Ivy Mike were only used a couple of times, were obsolete within the same month, and are nothing like the tens of thousands of weapons that have been in service starting in the '60s. They are of purely historical interest. --JWB (talk) 16:56, 25 November 2007 (UTC)
 * I suggest putting in details about the mk28 with a caveat that the drawing is not necessarily correct. It might be worth saying something to the effect "both have been tested" and that "gas boosting appears to be more common" though that statement would need a citation or three. Man with two legs (talk) 23:14, 28 November 2007 (UTC)

I will post some more intelligent replies later, but...

Solid Li-D fission stage boosting has been demonstrated - it's known as "pill boosting". It's described as "much harder" than gas boosting and modern warhead designs generally include features which are presumed to be part of gas boosting systems. How prevalent it was in any generation of deployed weapons is currently hard to guess based on purely public information.

Fusion boosting is more important to avoid predetonation than to make weapons immune to high radiation environments, though both are advantages.

Don't take the warhead diagrams and Mark-28 internal details too literally. The drawings are oversimplified and slightly wrong.

In terms of whether you'd boost a secondary's sparkplug with pure T or D-T mix, it's the same logic that applies to primaries. Modern weapons probably use D-T for both.

As far as I know, nobody has used shockwave imploding the gas to start any useful fusion reaction in a test or deployed nuclear weapon. Under ideal conditions it may be possible; the inside of a realistic bomb is likely not ideal enough.

Anyways, just a few comments off the top of my head. Back to the grindstone. Georgewilliamherbert (talk) 00:31, 27 November 2007 (UTC)
 * Thanks! Man with two legs (talk) 23:14, 28 November 2007 (UTC)

Rewrite
I have rewritten most of it. Positive criticism welcome. Man with two legs 22:43, 25 May 2007 (UTC)

Alarm clock/layer cake doesn't belong here
Apparently inclusion in this article was motivated by a final comment at the FAS site:

"'This design should probably be considered distinct from other classes of nuclear weapons. This design is something of a hybrid and could be considered either a type of boosted fission device, or a one-stage type of fission-fusion-fission bomb.'"

In actual usage "boosted fission weapon" always refers to a normal fission bomb with a small amount of fusion boosting at the center.

Boosting is used in all modern nuclear weapons, while Alarm Clock/Sloika designs are only of historical interest and were deployed briefly if at all.

The "one-state fission-fusion-fission bomb" is somewhat more accurate. The secondary of a radiation implosion weapon uses the same arrangement.

On the other hand if Alarm Clock can be considered a boosted fission device, so can staged thermonuclear weapons, which usually also derive most of their yield from fission.

I am going to remove the section from the article. --JWB (talk) 01:30, 1 January 2008 (UTC)
 * That is wrong, it certainly was not derived from the FAS site. I rewrote the article from my own knowledge.  If you look up Boosting in the index of Lorna Arnold's book, you get references to both Alarm clock and Joe 4 so the term is used in both contexts. Man with two legs (talk) 12:02, 6 January 2008 (UTC)
 * On p.86-87 she uses the terms "core boosting" and "tamper boosting" to distinguish the two, and that is something that is worth putting in the article. Man with two legs (talk) 12:58, 6 January 2008 (UTC)
 * I also think there is a fundamental difference between a bomb that uses the Li-6 D / U-238 cycle with little compression, and one that achieves D-D fusion by colossal compression. Man with two legs (talk) 12:10, 6 January 2008 (UTC)

Li-D requires similar compression to D-D; in fact according to NWFAQ 4.4.5.3.2.1 Li-D relies on D-D for its initial neutrons (so requires the same temperature and compression) and fission neutrons do not play a significant role. So there is little difference.
 * That is not correct: Joe-4 was a single stage weapon and could not possibly have had a high level of compression. The comment in the nuclear weapons archive is presumably correct when the fission spark-plug in the secondary is small and D-D fusion is able to happen for other reasons (ie high compression). Both Joe-4 and the early British H-bombs were certainly using fision neutrons to create tritium from Li-6.  At that stage, they had not realised that D-D fusion was possible at a fast enough rate. Man with two legs (talk) 13:56, 6 January 2008 (UTC)
 * That is true of Joe-4 (when you said Li-6 D / U-238 cycle it sounded like you meant radiation implosion weapons), however NWFAQ never refers to the Alarm Clock/Sloika design as "boosted" or "boost"ing, and neither have any other sources I have seen except for that one book on the British program. --JWB (talk) 16:38, 6 January 2008 (UTC)
 * In fact the top of NWFAQ 4.3 specifically contrasts fusion boosting (small amount of gas in core) with Alarm Clock/Layer Cake as two different kinds of designs, making clear it is not applying the term boosting to the latter. This is normal usage and there is no reason to suppress it in the article. --JWB (talk) 16:58, 6 January 2008 (UTC)

Arnold pp. 86-87 is quoting British scientist Keith Roberts speculating in 1955 without full knowledge of the American program. As Arnold notes on p. xiii, the British at the time were confused and inconsistent in their use of nuclear weapon terminology. And on p. 223 she defines boosted bombs in a way that would include most later thermonuclear weapons.
 * Correction: it is page 233. That definition fits both core and tamper boosting, but would not fit any bomb with a high fusion yield. Man with two legs (talk) 14:07, 6 January 2008 (UTC)
 * Most later weapons derived a majority of yield from the final fission stage. The Mk-21 is the only deployed weapon I've confirmed to not have the final fission stage. --JWB (talk) 14:31, 6 January 2008 (UTC)
 * There is clearly a fundamental difference between a weapon that could have a high fusion yield if the designers felt like it, and one that could not. And there is a clear difference in the reactions going on. Man with two legs (talk) 15:03, 6 January 2008 (UTC)
 * The fundamental difference is staging and radiation implosion. Other than that, the secondary of a Teller-Ulam weapon is similar to the Alarm Clock/Sloika design. There is no difference in the reactions going on, unless you are thinking of Ivy Mike, which was apparently the only non-lithium thermonuclear bomb ever tested. --JWB (talk) 16:22, 6 January 2008 (UTC)
 * You could not be more wrong. You do not get significant D-D fusion in single stage thermonuclear weapons and you do get it in two-stage weapons. Man with two legs (talk) 17:19, 6 January 2008 (UTC)

In the weapons designs the US standardized on by the 1960s and deployed in the tens of thousands to the exclusion of anything else, "boosted fission weapon" always refers to small amounts of fusion fuel inside the primary's pit. In contrast the British experiments were a short-lived dead end, abandoned after the US agreed to share its technology.

I think it is fair to say that while "boosting" may have been used early on to refer to various uses of fusion to supply neutrons for fission, "boosted (fission) weapon" and "boosting" have more specific connotations in the context of the actual US nuclear arsenal and program, as it stabilized after the experiments of the first few years. --JWB (talk) 13:30, 6 January 2008 (UTC)
 * As I see it, the fact that the term "boosting" has been used in both contexts is reason to include both in the article. It is entirely appropriate that the fact that tamper boosting is obsolete and that boosting now almost always means core boosting should be clearly stated, and that is not far off the current state of the article. Man with two legs (talk) 14:03, 6 January 2008 (UTC)

US centric view not appropriate

 * Incidentally, there is no case for making this article US-centric. The Russians and British certainly developed successful h-bombs before it was known how the US did it, and I guess the French and the Chinese did the same. Man with two legs (talk) 14:14, 6 January 2008 (UTC)

 * I don't know of any evidence that the Russians used the word "boosted" or equivalent, or categorized the Sloika design as similar to fission bombs with tiny amounts of gas boosting rather than similar to Teller-Ulam designs. The French, Chinese and later nuclear powers went straight to Teller-Ulam designs as by then this was known to be the way to go, and again we don't have any evidence on their usage of "boost" or equivalent words. The point is not that Alarm Clock/Sloika designs should not be documented, but that they primarily belong in the articles on the history of nuclear weapons in general or at least thermonuclear weapons, not in a much more specific article answering the question of what "boosted fission weapon" normally means. --JWB (talk) 14:31, 6 January 2008 (UTC)
 * The fact that the term "boosting" has been officially used in both contexts is all the reason needed to include both in this article. Man with two legs (talk)
 * Officially by who? There is even less case for making the article UK-centric. --JWB (talk) 16:18, 6 January 2008 (UTC)
 * By the Ministry of Defence (United Kingdom) who own the copyright on Arnold's book. And I am not suggesting making the article anything but English-language-centric.  Now stop wasting my time. Man with two legs (talk) 17:07, 6 January 2008 (UTC)
 * Now that we know where and when "boosting" was used to describe one-stage layer cake weapons, those specifics can be added to the article. --JWB (talk) 01:24, 7 January 2008 (UTC)

 * BTW, what other countries have Teller-Ulam weapons? Man with two legs (talk) 14:46, 6 January 2008 (UTC)
 * Teller-Ulam design says right at the top that France and China have them. --JWB (talk) 16:18, 6 January 2008 (UTC)
 * I was referring to the "later nuclear powers" you alluded to above. Man with two legs (talk) 17:07, 6 January 2008 (UTC)
 * Israel is suggested in the Teller-Ulam article. Many sources say Israel has thermonuclear weapons including neutron bombs, which can only be done as a radiation implosion design. states that all later nations have used the Teller-Ulam design. --JWB (talk) 01:24, 7 January 2008 (UTC)

Questioning the need for this article
1. This article has been rated Start-Class and has a warning about lack of sources.

2. The bulk of this information has been incorporated into Nuclear weapon design where the reader can see it in a useful broader context.

3. Instead of fixing it and bringing it up to acceptable quality, should it be simply eliminated?

HowardMorland (talk) 12:28, 8 May 2008 (UTC)

 * 1) Sources have in fact been added since the lack of sources tag, which is now incorrect. The Start-Class tag also dates back some time.
 * 2) I think this article does in fact have more detail and can be considered a subarticle. Nuclear weapon design is already longer than policy suggests; when you edit it, you get a warning This page is 84 kilobytes long. It may be appropriate to split this article into smaller, more specific articles. See Article size. Given this, it will have to summarize and send more detailed coverage to subarticles soon, if not already.
 * 3) What fixes do you think are necessary?

Teller-Ulam design, on the other hand, is closer to a duplicate article on the whole topic, though it still has some difference in emphasis.

One split that has occurred to me as reasonable is an article on History of nuclear weapons vs. a Nuclear weapon design that concentrates on modern designs. --18:01, 8 May 2008 (UTC)

Last section still problematic
Early thermonuclear weapon designs such as the Joe-4, the Soviet "Layer Cake", used large amounts of fusion to induce fission in the uranium-238 atoms that make up depleted uranium.
 * What is a "large amount"? It is not large compared with the amount of fusion in a Teller-Ulam (two-stage) design.
 * Also, why only list depleted uranium and exclude natural and enriched uranium?

These weapons had a fissile core surrounded by a layer of lithium-6 deuteride, in turn surrounded by a layer of depleted uranium. Some designs (including the layer cake) had several alternate layers of these materials.
 * Why not just say they had multiple layers then? Alarm Clock also had multiple layers.

The Soviet Layer Cake was similar to the American Alarm Clock, which was never built, and the British Green Bamboo, which was built but never tested.

When this type of bomb explodes, the fission of the highly enriched uranium or plutonium core creates neutrons, some of which escape and strike atoms of lithium-6, creating tritium.
 * Fissile should not be described as "core" if much of the fusion fuel is inside some fissile layers.

At the temperature created by fission in the core, tritium and deuterium can undergo thermonuclear fusion without a high level of compression. The fusion of tritium and deuterium produces a neutron with an energy of 14 MeV—a much higher energy than the 1 MeV of the neutron that began the reaction. This creation of high-energy neutrons, rather than energy yield, is the main purpose of fusion in this kind of weapon.
 * It is the main purpose of fusion in almost all staged thermonuclear weapons too, so this sentence is misleading.

This 14 MeV neutron then strikes an atom of uranium-238, causing fission: without this fusion stage, the original 1 MeV neutron hitting an atom of uranium-238 would probably have just been absorbed. This fission then releases energy and also neutrons, which then create more tritium from the remaining lithium-6, and so on, in a continuous cycle. Energy from fission of uranium-238 is useful in weapons: both because depleted uranium is very much cheaper than highly enriched uranium and because it cannot go critical and is therefore less likely to be involved in a catastrophic accident.
 * Decreased criticality is true not only of depleted and natural uranium, but also low-enriched uranium and even uranium with U-235 content slightly greater than 20%, the definition of HEU.

This kind of thermonuclear weapon can produce up to 20% of its yield from fusion, with the rest coming from fission and is limited in yield to less than one megaton of TNT (4 PJ) equivalent. Joe-4 yielded 400 kilotons of TNT (1.7 PJ). In comparison, a true hydrogen bomb produces typically 50% of its yield from fusion, with 97% having been achieved, and there is no upper limit to its explosive yield.
 * Estimates of 75% or more are what I've been hearing.

4 grams per warhead needed?
There is a source and some usable content at Tritium that could be moved or copied here. The source by Hisham Zerriffi says "the estimated quantity needed is 4 grams per warhead." -- Petri Krohn (talk) 13:52, 21 November 2010 (UTC)

That photo
This article is not about multi-stage weapons, and yet it has a photo of one being tested (Ivy Mike). 180.200.183.94 (talk) 11:19, 27 February 2015 (UTC)

External links modified
Hello fellow Wikipedians,

I have just added archive links to 1 one external link on Boosted fission weapon. Please take a moment to review my edit. If necessary, add after the link to keep me from modifying it. Alternatively, you can add to keep me off the page altogether. I made the following changes:
 * Added archive https://web.archive.org/20080708193625/http://www.isanw.org/facts/weapons.html to http://www.isanw.org/facts/weapons.html#node8

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Link to German Wikipedia Article
There is no link to a German article, and I do not know how to edit links, so maybe somebody can help? Deutsch https://de.wikipedia.org/wiki/Kernwaffentechnik#Geboostete_Spaltbomben

The German article is organized in a different manner. Boosted weapons is a section of "nuclear weapon technology". The link I'm giving is to the appropriate section.

76.254.31.171 (talk) 06:33, 17 January 2017 (UTC)

Bad section
Some of this article is very misguided. The problems seem so consistently wrong in the following quote that it is hard to imagine it is not intentionally wrong: . '....Deuterium-tritium fusion neutrons are extremely energetic, seven times more energetic than an average fission neutron, which makes them much more likely to be captured in the fissile material and lead to fission. This is due to several reasons: Their high velocity creates the opposite of time absorption: time magnification. When these energetic neutrons strike a fissile nucleus, a much larger number of secondary neutrons are released by the fission (e.g. 4.6 vs 2.9 for Pu-239). The fission cross section is larger both in absolute terms, and in proportion to the scattering and capture cross section...' . Not one of those supposed reasons is without serious problems.

The first reason, 'time magnification' is a made-up techno-sounding term. Note there is no link to any such buzz word in wikipedia. Note there is no footnote number for a supporting link for this or any of the claims in this section. Perhaps the author was dreaming about the relativistic effect known as 'time dilation'. If that was it, correcting the name won't help. Time dilation would delay the beta decay of free neutrons, but the halflife of that is many orders of magnitude higher than the processes discussed here and does not have any meaningful effect for nuclear weapons. . The second supposed reason fails because it is not related causally to the question it is supposed to answer, namely, why the more energetic d-t fusions neutrons might be more likely to be captured in fissile matetial and result in fission. The additional fission neutrons produced by d-t fusion neutrons is a result and not a cause of absorption. . The third supposed reason is just flat wrong. With the possible exception of u238 over very specific ranges, the absorption and fission crosssections are smaller at higher energies over an range of significance. . . Please review and delete this section. You can try to find support for those claims in question, but you will be looking a long time, so better to take out the offending inaccuracies in the interim. . 98.183.55.219 (talk) 18:19, 17 March 2017 (UTC)BGriffin

 * So... This came from: Carey Sublette's NW FAQ sec 4.3.1 and the original source says:
 * 4.3.1 Fusion Boosted Fission Weapons
 * Fusion boosting is a technique for increasing the efficiency of a small light weight fission bomb by introducing a modest amount of deuterium- tritium mixture (typically containing 2-3 g of tritium) inside the fission core. As the fission chain reaction proceeds and the core temperature rises at some point the fusion reaction begins to occur at a significant rate. This reaction injects fusion neutrons into the core, causing the neutron population to rise faster than it would from fission alone (that is, the effective value of alpha increases).
 * The fusion neutrons are extremely energetic, seven times more energetic than an average fission neutron, which causes them to boost the overall alpha far out of proportion to their numbers. Is this due to several reasons:
 * 1. Their high velocity creates the opposite of time absorption - time magnification.
 * 2. When these energetic neutrons strike a fissile nucleus a much larger number of secondary neutrons are released (e.g. 4.6 vs 2.9 for Pu-239).
 * 3. The fission cross section is larger in both absolute terms, and in proportion to scattering and capture cross sections.
 * Taking these factors into account, the maximum alpha value for plutonium (density 19.8) is some 8 times higher than for an average fission neutron (2.5x10^9 vs 3x10^8).
 * Obviously someone has subsequently attempted to simplify and mangled some of the technical details. Losing the "boost the alpha" bit is a key tech detail whoever edited it lost / did not understand.  Obviously not a bomb designer there, but no Wikipedia expectations that editors are experts.
 * It's not a good idea to yank it all out. Fixing the goofs in "improvements" would be a good idea.  And it should be a cited quote as it's lifted from an external source (I expect / hope Carey wouldn't mind but it needs to credit it appropriately, and despite knowing him I can't speak for him or his intellectual property rights). Georgewilliamherbert (talk) 00:48, 18 March 2017 (UTC)
 * Taking these factors into account, the maximum alpha value for plutonium (density 19.8) is some 8 times higher than for an average fission neutron (2.5x10^9 vs 3x10^8).
 * Obviously someone has subsequently attempted to simplify and mangled some of the technical details. Losing the "boost the alpha" bit is a key tech detail whoever edited it lost / did not understand.  Obviously not a bomb designer there, but no Wikipedia expectations that editors are experts.
 * It's not a good idea to yank it all out. Fixing the goofs in "improvements" would be a good idea.  And it should be a cited quote as it's lifted from an external source (I expect / hope Carey wouldn't mind but it needs to credit it appropriately, and despite knowing him I can't speak for him or his intellectual property rights). Georgewilliamherbert (talk) 00:48, 18 March 2017 (UTC)

Literature
I believe this is the technique used in the Tom Clancy book, The Sum Of All Fears. In the book, they discuss recovering a plutonium ingot from a Mark 12 bomb "lost" in the Yom Kippur war. The bulk of the story is about a former Soviet nuclear scientist and his protege that use metallurgical methods to reshape the ingot to produce a high yield weapon for some terrorists. At one point, they obtain some boosting fuel (it's been a while, could have been Lithium) that adds significant neutrons in order to make the explosion go from a 10Kt yield to a 400Kt yield. I read the Sum Of All Fears Wikipedia article just now, and it omits these details. Anyway, my point is, you might consider adding an "in the literature" section to call out to this. Maybe someone with more recent knowledge of the book can shore up my description. — Preceding unsigned comment added by 96.255.18.130 (talk) 11:18, 3 April 2017 (UTC)

Fusion? Not.
Lithium7, Deuterium, and Tritium participate in (n,2n) neutron doubling reactions. Deuterium splits circa 2MeV into proton and neutron. Beryllium9 generates neutrons from high MeV alpha emission in Polonium210/Beryllium neutron sources. Nazi Germany sought to enhance natural Uranium by adding “light metals” to increase Uranium neutron flux. Shjacks45 (talk) 00:03, 16 November 2019 (UTC)

title: Talk:Boosted fission weapon


text:
Gun Alley Murder

The Gun Alley Murder was the rape and murder of 12-year-old Alma Tirtschke in Melbourne, Australia, in 1921. She was a schoolgirl who attended Hawthorn West High School and had last been seen alive close to a drinking establishment, the Australian Wine Saloon; under these circumstances her murder caused a sensation.

More recently, the case has become well known as a miscarriage of justice. 29-year old Colin Campbell Ross was convicted and executed for Tirtschke's murder, but professed his innocence until his death. When the case was re-examined decades later, DNA evidence confirmed Ross's innocence, and in 2008 he was granted a posthumous pardon. Since Ross's arrest, Tirtschke's family believed that Ross was innocent and that the wrong man had been convicted for Tirtschke's murder.

Victim
Nell Alma Tirtschke, known as Alma, was born on 14 March 1909 at a remote mining settlement in Western Australia, the first child of Charles Tirtschke and Nell Alger. In 1911, Charles Tirtschke accepted a position with a mining company in Rhodesia (now Zimbabwe) and the family moved there, where Nell gave birth to a second daughter, Viola, in 1912. The family was returning to Australia in December 1914 when Nell died of complications relating to a third pregnancy and was buried at sea. After arriving in Melbourne, Charles was unable to care for the children and returned to Western Australia to work in the goldfields. Alma and Viola were cared for by their grandparents, Henry and Elizabeth Tirschke, who were assisted by their five adult daughters.

By 1921, Henry Tirschke had died and the grandmother assumed all parental duties. She was remembered by Viola as a strict disciplinarian who kept a close watch on both daughters. Alma was studious and well behaved, and excelled in her studies at the Hawthorn West Central School. However, her grandmother greatly restricted her from social activities with other students and she became very shy. An uncle, John Murdoch, said of Alma: "Though of a bright disposition, she was somewhat reserved, and did not make friends readily like some girls. She lacked the vivacious manner that encourages chance acquaintance". Her sister Viola described her as being "soft in speech and soft in manner".

Murder
Tirtschke's task that day had been to go from her grandmother's house in Jolimont to the butchers Bennet and Woolcock Pty. Ltd. on Swanston Street, collect a parcel of meat, drop it at an aunt's Collins Street home and return to Jolimont.

It was uncharacteristic for Tirtschke to take so long on her errands. A witness said he saw a man following Tirtschke. Reliable witnesses who had nothing to lose or gain by telling police what they knew said Tirtschke was dawdling, apprehensive and obviously afraid.

Just a few metres away from the Australian Wine Saloon in the Eastern Arcade, between Bourke and Little Collins Streets, where Alfred Place runs off Little Collins Street (next to present day 120 Collins St), Tirtschke was last seen about 3 pm on 30 December 1921. Her naked body was found early the next morning in a lane running east off Gun Alley, not far from Alfred Place.

Investigation
Following the discovery of the body, the owner of the Australian Wine Saloon, Colin Campbell Ross, was charged with her rape and murder. The case against him was based on the evidence of two witnesses, plus some strands of red hair, apparently from Tirtschke's head, which provided a vital connection between Ross and the murder. Ross protested his innocence but was hanged on 24 April 1922 at Melbourne Gaol.

Ross's lawyer Thomas Brennan was convinced of his client's innocence and tried in vain to have the case appealed all the way to the Privy Council. Brennan would later go on to become an Australian senator.

The two witnesses, Ivy Matthews and the fortune teller Julia Gibson, were later considered by many to be unreliable, both having had a motive to lie. The saloon had recently sacked Matthews from her position as a barmaid, and Gibson was boarding with Matthews at the time. The only credible piece of evidence was the red hair that connected Ross to the case. Ross could also account for his movements at the time Tirtschke disappeared, and later that night, when her body was dumped in Gun Alley. With nothing to hide, Ross had told detectives who interviewed him that a little girl matching Tirtschke's description had passed his saloon, but that this was his only connection with the victim.

Pardon
More reliable forensic examinations in the 1990s disproved the red hair connection and showed that Ross was innocent. After an enquiry by three judges in 2006, Ross was subsequently granted a pardon on 22 May 2008, the date on which the Victorian governor, as the Queen's representative, signed it. The pardon was announced publicly on 27 May 2008. It is the first – and to date only – pardon for a judicially executed person in Australia. In the book which led to Ross's pardon, author Kevin Morgan revealed for the first time the evidence missed by the police in their original investigation and identified by name Tirtschke's probable killer: a man mistrusted by Alma and Viola – George Murphy – a returned soldier who had paedophilic tendencies and who was married to their cousin.

In popular culture
The Gun Alley Murder is depicted in 1982's Squizzy Taylor, a film about the eponymous Melbourne gangster. The film portrays Taylor (David Atkins) assisting the authorities with the case by intimidating supposed witnesses into revealing what they know about Ross.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Gun Alley Murder


text:
Grind (2003 film)

Grind is a 2003 American skateboarding comedy film directed by Casey La Scala, and written by record producer Ralph Sall, who also composed the score. The film stars Mike Vogel, Vince Vieluf, Adam Brody and Joey Kern as four teenage aspiring amateur skaters trying to make it in the world of pro skateboarding by pulling insane stunts in front of their pro skater idol. It was critically panned and flopped at the box office.

Plot
Following high school graduation, skateboarder Eric Rivers and his best friends, goal-oriented workaholic Dustin Knight and misfit slacker Matt Jensen, have one last summer road trip together to follow their dream of getting noticed by the pro skater world — and getting paid to skate. When the legendary Jimmy Wilson's demo tour comes through, the boys figure that as soon as he sees their fierce tricks, he'll sign them up for his renowned team immediately, right? Unfortunately, the guys are intercepted by Wilson's road manager and can't get their foot in the door, much less their boards. Following their dream — and Wilson's national tour — the trio start their own skate team, reluctantly sponsored by Dustin and his college fund.

After recruiting laid-back ladies man "Sweet" Lou Singer to join their crew and provide the van for their tour, team Super Duper launches the ride of their lives in an outrageous road trip from Chicago to Santa Monica. The professional scene doesn't exactly welcome nobody, but these outsiders stick together through extreme misadventures. In their quest to go pro, they meet professional vert skating champions Bucky Lasek, Bob Burnquist and Pierre Luc Gagnon, skate pro Bam Margera and his crew Preston Lacy, Ehren Danger McGhehey and Jason Wee Man Acuña, as well as sexy skate chick Jamie as they grind handrails across America and force the skateboarding world to give 'em a piece of the action.

Soundtrack
A soundtrack consisting of a blend of rock, hip hop and reggae music was released on August 12, 2003, by Atlantic Records.

Critical response
The film received generally negative reviews from critics. Review aggregator Rotten Tomatoes gives the film an 8% based on 74 reviews, with an average score of 3.1/10. The site's consensus states: "Mediocre skateboard stunts are padded by a half-baked plot and one-dimensional characters." Metacritic gave it an average score of 30 out of 100 based on reviews from 24 critics, indicating "generally unfavorable reviews".

Joe Laydon, of Variety called the "Skating scenes ... unremarkable and repetitious," concluding that the film was less than good.

Keith Phipps, for The A.V. Club, said "The film ... will gleam the cube only of viewers with an unusually high tolerance for porta-toilet and Dutch-oven gags."

title: Grind (2003 film)


text:
Wikipedia:Articles for deletion/Rumored Singles, Ace of Base

 * The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or on a Votes for Undeletion nomination).  No further edits should be made to this page.

The result of the debate was DELETE. — J I P | Talk 16:01, 18 October 2005 (UTC)

Rumored Singles, Ace of Base
IMO, this doesn't deserve its own article. I'm not even convinced that it should be merged into the Ace of Base article, as it's mostly built on rumour and suposition, and thus unverifiable. Hence, delete CLW 14:16, 11 October 2005 (UTC)
 * Delete. Wikipedia is not a crystal ball. / Peter Isotalo 15:36, 11 October 2005 (UTC)
 * Delete as per above. -- Rune Welsh | ταλκ | Esperanza  18:10, 11 October 2005 (UTC)
 * Delete per above. Andrew pmk | Talk 01:03, 12 October 2005 (UTC)
 * Delete. --badlydrawnjeff 13:37, 12 October 2005 (UTC)
 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in an undeletion request). No further edits should be made to this page.


text:
Imilac

Imilac is a pallasite meteorite found in the Atacama Desert of Northern Chile in 1822.

Classification
Imilac is classified as a stony–iron pallasite. Imilac specimens are highly prized by meteorite collectors due to its high concentration of beautiful olivine grains.

Strewn field
Numerous masses were found in a valley to the SW of Imilac. The total weight of the Imilac fall is estimated to be around 1000 kg. The primary strewn field is long about 8 km.

Specimens
Due to weathering, intact olivine grains are present only on large specimens (over 1 kg). Smaller samples contain darker altered olivine crystals. On the market there are also a lot of very small (few grams) Imilac individuals called metal skeletons: they are severely weathered and lack olivine grains.

title: Imilac


text:
Sukumar Azhikode

Koloth Thattarath Sukumaran, popularly known as Sukumar Azhikode (26 May 1926 – 24 January 2012) was an Indian academic, orator, critic and writer of Malayalam literature, known for his contributions to Malayalam language and insights on Indian philosophy. He was a scholar in Sanskrit, Malayalam, and English languages and his work, Tatvamasi, published in 1984, is a notable work for its detailed interpretation of Indian philosophy, Vedas and Upanishads. He was a recipient of several honours including Sahitya Akademi Award, Kerala Sahithya Akademi Award, Vayalar Award, Vallathol Award and Ezhuthachan Puraskaram, the highest literary award of the Government of Kerala. The Government of India awarded him the fourth highest civilian honour of the Padma Shri in 2007, which he refused citing the award was a discrimination.

Biography
Sukumar Azhikode, was born on May 12, 1926, at Azhikode, a coastal village in Kannur district of the south Indian state of Kerala to Vidwan Panankavil Damodharan, a teacher, and his wife, Koloth Thattarathu Madhaviyamma, as the fourth of their six children. His early schooling was at Azhikode South Elementary School and he passed intermediate examination from Rajas High School Chirakkal in 1941 before studying ayurveda at Kottakkal Arya Vaidya Patasala for one year. Subsequently, he joined St. Aloysius College, Mangalore from where he graduated in commerce in 1943. He started his career as a clerk at the Kannur branch of Indian Overseas Bank but soon quit the job to pursue a teaching career for which he completed the teachers' training course from Government College of Teacher Education, Kozhikode (GCTE) and joined his alma mater, Rajas High School, Chirakkal, as a teacher in 1948. While serving as a teacher, he continued his studies through distance education and earned master's degrees in Sanskrit and Malayalam languages. He followed it up with a bachelor's degree in education from GCTE in 1952. During the next three and a half decades, he worked at various institutions, starting with St. Joseph's College, Devagiri and St. Aloysius College, Mangalore as a lecturer, as the principal at SNM Training College, Moothakunnam, before joining the University of Calicut as the founder head and professor of the department of Malayalam. In between, he secured a PhD in Malayalam literature in 1981, for his thesis, Western Influence in Malayalam Literary Criticism. Later, he served as the pro vice chancellor and acting vice chancellor of the university.

Sukumar Azhikode lived a bachelor throughout his life; his relationship with Vilasini teacher, to whom he had proposed, did not result in a marriage. He lived in Eravimangalam near Thrissur, towards the later part of his life and died on 24 January 24, 2012, at Amala Institute of Medical Sciences. He was 85 years old and was suffering from bone cancer for which he had been hospitalized since 7 December 2011.

Anecdote: Azhikode had an accident in the early 2000s when he was returning to his Thrissur home after a speech. He had caught an auto from Thrissur railway station but had an accident resulting in wound to head. Since this happened in the early hours of the morning, the auto driver drove him to some of the private hospitals in Thrissur. Unfortunately since this was an accident case and Azhikode had blood over his white kurtha, he was refused treatment. The staff that refused him treatment did not realise his identity in the early morning hours. After a few failed attempts, Azhikode himself requested the auto driver to drive him to his friends house at Punkunnam. This friend was Dr TI Radhakrishnan, a renowned physician and neurologist. This is the same Doctor who had looked after some of the other literary and cultural giants such as Vailopilli, G Kumarapillai, MK Menon Vilasini, Krishnankutty Poduval of Kathakali etc. Azhikode was provided with all necessary care including Dr Nalini Radhakrishnan suturing his forehead wound. Azhikode stayed at his friend Dr Radhakrishnan’s clinic for few weeks before going home. They remained very close friends until his death.

Literary career
Sukumar Azhikode, considered by many as the leading Malayalam literary critic after the era of Joseph Mundassery, M. P. Paul and Kuttikrishna Marar and one of the greatest Malayalam orators, wrote a number of books on literary criticism, philosophy and social issues,  including Thatvamasi, a treatise on Indian philosophy, Vedas and Upanishads which received 12 awards; the book also paved way for another book, Thathwamasi Prabhashanangal, a compilation of four speeches made by Azhikode on the book. Six of his books are on Malayalam literature,; Malayala Sahityavimarsanam (Criticism of Malayalam Literature) and Malayala Sahitya Patanangal (Studies on Malayalam Literature) are general studies, two others, Shankarakkuruppu Vimarshikkappedunnu (Sankara Kurup Critiqued) and Mahakavi Ulloor (The Great Poet Ulloor) are studies of the works of G. Sankara Kurup and Ulloor S. Parameswara Iyer while the remaining two, Aasaante Seethaakaavyam (Asan's Seetha Kavyam) and Ramananum Malayalakavitayum (Ramanan and Malayalam Poetry) are critical analysis of two classic poems, Chinthavishtayaya Seetha of Kumaran Asan and Ramanan of Changampuzha Krishna Pillai. Besides several studies on various topics, he also published a book compiling some of his orations under the title, Azhikodinte Prabhashanangal(Orations of Azhikode) and Azhikodinte Phalithangal (Jokes of Azhikode) which narrates his jokes and their situations. He also translated Mark Twain's The Adventures of Huckleberry Finn into Malayalam under the title, Huckleberry Finninte Vikramangal.

Social activism and controversies
Sukumar Azhikode was an active commentator on the changes in the society and his speeches on the demolition of the Babri Masjid were reported to have been notable; his speeches regularly featured comments on historical figures such as Buddha, Jesus Christ, Muhammad, Gandhiji and Ram Manohar Lohia. He was also vocal on contemporaries including V. S. Achuthanandan, G. Sankara Kurup and K. Karunakaran, among others. His war of words with Mohanlal, the Malayalam film actor, drew public interest, and led to Azhikode serving a legal notice on the actor. He was also involved in public exchanges of differences with Vellapally Natesan, the general secretary of Sree Narayana Trust and Innocent, the film actor and contested an election to the Lok Sabha, unsuccessfully, the only time he was involved in active politics.

Awards and honours
Sukumar Azhikode received the Kerala Sahitya Akademi Award for literary criticism in 1984 for his work, Malayala Sahitya Vimarshanam; a year later, Akademi honoured him again with their award for miscellaneous works; Thatvamasi earning him the award. Thatvamasi received another honour the next year in the form of 1985 Sahitya Akademi Award, followed by yet another award, Vayalar Award in 1989. He was the recipient of the 1997 DALA Award of the Dubai Art Lovers Association. The Government of Kerala awarded him for their highest literary honour, the Ezhuthachan Puraskaram, in 2004 and the Government of India selected him for the fourth highest civilian award of the Padma Shri in 2007. However, Azhikode refused the award, citing that the gradation of civilian honours were a form of discrimination. He was also a recipient of the Vallathol Award which he received in 2007 and the Rajaji Award. The Government of Kerala acquired the property of Sukumar Azhikode in 2013 and set up a memorial for him. The memorial holds a museum where his books and personal belongings are on display. Another memorial for the writer has been set up at Payyambalam Beach by Sukumar Azhikode Cultural Center and a Kannur-based cultural association has instituted an annual award, Sukumar Azhikode Memorial Award; M. Mukundan, K. Jayakumar and Sreekumaran Thampi are some of the recipients of the award.

title: Sukumar Azhikode


text:
Category talk:Redirects from other capitalisations

Is there any value
Seems a good idea - but these are automagically recognisable by any software producing a printed copy, so is there any other value? Rich Farmbrough 14:17, 11 October 2005 (UTC)

What was the original intention
Hmm. My comment is one year and one month and one day after yours. Anyways, I'm wondering if these are meant for redirects with lowercase last names, such as Bill clinton and Derek jeter. If the category and template were taken literally, tens of thousands of not currently tagged redirects would belong in here. However, scanning the entries, there don't seem to be many redirects of that sort. Does anyone know what the original intention was? Picaroon9288 17:56, 12 November 2006 (UTC)

Fixing double redirects bots
When a bot fixs a double redirect may broke the sense of the template. Solution? --Emijrp (talk) 18:17, 25 November 2007 (UTC)
 * Ask the bot operator to stop it while the bot vandalizes. There is something on the page which the bot doesn't understand, if the operator can't be bothered to use his/her/its time to look at the page, s/h/it should not let the bot vandalize the page. Erik Warmelink (talk) 22:56, 6 January 2009 (UTC)

Question
I thought that title searching wasn't case sensitive. That is, if someone linked on or searched for an article title with an alternative capitalization, then the user would be taken directly to the correct page. Am I mistaken? If I'm not mistaken, then why go to all the trouble of creating a redirjbhhjhgh khghg khghg jkhgf tuirtrf iy iuyt ect page for something that happens automatically? Rklawton 16:11, 30 November 2007 (UTC)
 * There are two cases:
 * 1) If you write "albert einstein" on search box, you will be redirected to Albert Einstein, because all first-word-letters are capitals. Then, Albert einstein redirect ins't useful for search purposes.
 * 2) If you write "vincent van gogh" on search box, you won't be redirected to Vincent van Gogh unless a redirect as vincent van gogh or Vincent Van Gogh exists. These redirects are useful for search purposes. --Emijrp 18:10, 30 November 2007 (UTC)
 * I wasn't aware of the latter case; thanks, I'm suitably enlightened.  However, the majority of these would seem to in the former category.  They don't help with search, and arguably, worsen matters slightly by resulting in an essentially spurious "redirected from" message.  They shouldn't be linked to, either, since that would be introducing a capitalisation error into another article, and makes correction of same less likely, due to the spuriously-blue link.  If at all possible, we should prevail on people not to bother creating these, and maybe even start to think about deleting some of them.  Alai (talk) 04:06, 10 December 2007 (UTC)

Shortening category blurb
13-Feb-2008: The intro blurb for the category filled my screen, so I shortened that intro text by 12 lines. Perhaps it should say, "Refer to doc page for further explanation" of the category. I cut 12 output lines by:
 * removed redundant words when the meaning appeared obvious;
 * omitted prefix "Template:" to list 7 names on 2 lines (not 4);
 * removed ruler lines and blank lines;
 * used some small-font (not "<big>") to compress page length;
 * converted "See-also" header/section break to one-line "Also see".

Everything was very wordy: I would have called the template "Redirectcaps" as just 12 letters with one spelling, not 8 templates with 30-letter names. When I first saw the template name, I couldn't understand what "R from" even meant, but now I understand a desperation to abbreviate redirect as "R". It is easy to see why U.S. Gov't manuals are written about "standards for naming" to generate a simple name such as "Redirectcaps" before 8 rambling names get concocted. The category is more evidence of how many thousands of rambling names are getting crammed into Wikipedia, in the manner of an ageing bureaucracy. -Wikid77 (talk) 10:37, 13 February 2008 (UTC)

I don't get it
I totally understand the point of capitalization-related redirects. I don't get why this category exists. What's the deal? -Rrius (talk) 02:57, 11 December 2008 (UTC)

 * dunno about you but I rarely use the search box, it's usually much quicker to just type www.wikipedia.org/wiki/whatever in the address bar.. firefox even easier because it fills most of it in so you just ctrl+shift+leftarrow then type the title :) but sometimes stuff is missing and then you have to mess around searching --Kittins floating in the sky yay (talk) 14:55, 21 March 2009 (UTC)

Nominated for deletion
I've nominated this category for deletion here. --MZMcBride (talk) 06:14, 4 May 2009 (UTC)
 * "The result of the discussion was a clear swing towards keep" at Templates for deletion/Log/2009 May 4. See there for the arguments-- basically it was because 1/ these redirects are useful for linking, tho they may not be needed for searching and 2/ that it is necessary in order to establish these as  Unprintworthy redirects.  DGG ( talk ) 19:53, 5 September 2009 (UTC)

Creating redirects with bot
Please, check this Bots/Requests for approval/BOTijo 2 (again). emijrp (talk) 15:46, 25 June 2009 (UTC)

Unprintworthy
I've put this category in the larger cat Category:Unprintworthy redirects as I think none but one form of capitalisation is ever likely to be used in print. Please let me know if I've erred in this. Declan Clam (talk) 17:58, 27 October 2009 (UTC)

Is something wrong?
Not sure, but something seems to be wrong with the Category page. It freezes up my browser, so I have to "hard-exit". Then I have to login and start all over again. I come across many cat pages, and this one is the first and only one to freeze up my IE8. It's as if there's far too much code on this page. Also, I installed R from other capitalisation on this Redirect, but it does not appear after saving. Has somebody hidden it? Is something wrong?

—  Paine Ellsworth  (  CLIMAX  )  09:08, 26 December 2010 (UTC)

Hello? Anybody home? —  Paine Ellsworth  (  CLIMAX  )  09:42, 6 January 2011 (UTC)

Okay, I did the things the MS engineers suggest, and they helped, but there still appears to be something wrong with the delayed loading of this page. It obviously has something to do with the Category template it calls, because that template behaves the same way. So I replaced it with the normally used Template:Category TOC, and everything works fine. I'm going to continue an investigation into what is wrong with tl| Large category TOC.

—  Paine Ellsworth  (  CLIMAX  )  19:09, 12 January 2011 (UTC)

 * PS. At least temporarily, I went with LargeCategoryTOC2. Revert if you must, however there is still something wrong with tl| Large category TOC.

 * PPS. I had a problem with another cat, Category:WikiProject Biography articles, and when I did as the MS engineers suggested, which was to >start >Run >regsvr32actxprxy.dll in the field, run it and wait for the Success box, then restart computer, it helped a little on that cat. However, even after I did this, and even when I ran IE8 without add-ons, this cat still loads extremely slowly, although a little faster than before, but not much. (Note:  That applies only to when Large category TOC is used on these cat pages.  When LargeCategoryTOC2 is used, the pages load without any delay.)

Figured it out. The problem ultimately lies with Large category TOC/a-z. While that subpage template appears innocuous, it gets called for each letter of the alphabet in Template:Large category TOC, and thereby slows the load time tremendously of any other entity that calls the Large category template, such as this category. One has to ask oneself, "Why should all those calls be necessary? How many pages will begin with 'Bq' or 'Pz'?" The work-around is to switch to the usage of LargeCategoryTOC2, which calls the subpage "/aejot" instead of "/a-z". This gives five (sensible) choices for each start-letter rather than twenty-six (most of which are never used), and it takes way less time to load. So I have converted this cat to the TOC2 template call. End of problem, I sincerely hope.

—  Paine Ellsworth  (  CLIMAX  )  05:15, 14 January 2011 (UTC)
 * PS. And yes, I figured out the one about the cat not showing up on the Redirect. The main other template has been installed on the Rcat, so it will only categorize redirects in the Main namespace.  Since the Rcat has its own /doc page, I have noted this on that doc so that future editors won't waste a lot of time wondering why the cat doesn't show up on their newly edited redirect.

Since repeated attempts have shown no difference in load time for me and I will not go one page at a time to get to where the non-standard characters may be, I changed it back to TOC. JimCubb (talk) 20:41, 8 February 2011 (UTC)


text:
Talk:Electrical resistivity and conductivity

Mistaken postulate in Definition section?
Just a quick question. Unless I misunderstand something, under the heading "definition", it seems like the discussion about the definition of resticivity mistakenly reverses the point. Resticivity is defined as R=V/I, which is an intrinsic property of materials, while p=R*A/l specifies, as I read it, the resistance of an OBJECT, which varies with its geometry and is thus determined by its geometry and the intrinsic property, R, of its substance. But the article states the opposite. Or what? I know nothing about the subject, so might just be misreading it. I.e. it says:

"The reason resistivity is defined this way is that it makes resistivity an intrinsic property, unlike resistance.", but the rest of the content indicates that the words have just been swapped by mistake. I will not correct it, since I am no expert, but I urge someone to correct it if it is a mistake.

 * You say "V/I is an intrinsic property of materials" but that's not true. A long thin copper wire has a different V/I from a short thick copper wire, even though both are copper. --Steve (talk) 12:06, 16 May 2016 (UTC)

 * Don't think there's anything mistaken here. As Steve stated, V/I or resistance isn't a property of materials. You seem to have mixed the two up. A piece of a substance has a certain resistance but a substance itself has a certain resistivity rho. An analogue that might be familiar to you is mass vs density. Density is defined as mass per unit volume, making it an intrinsic property of a substance itself. Similarly with resistivity, we are looking at resistance per unit length of wire, adjusted for the cross sectional area of the wire. If you measure the resistivity or density of a substance, it will always come out the same regardless of the sample or the size. 67.188.175.172 (talk) 10:56, 9 January 2018 (UTC)James

Dubious phrase

 * There is a hypothesis that electron pairing in high-temperature superconductors is mediated by short-range spin waves known as paramagnons

This phrase caught my eye because of new term I made redlinked. I did some reading and found  this text saying that paramagnons are in fact suppress superconductivity. So, how they can "mediate"? Does somebody have access to the footnoting article to verify what it actually says? Staszek Lem (talk) 20:22, 5 August 2016 (UTC)

 * There are different kinds of superconducting states. If I am not mistaken, the text you refer to talks about conventional s-wave superconductivity. The high-Tc state is usually assumed to be d-wave, and the shape of the Fermi-surface also plays a role, so that the effect can be different. This is a complicated subject which I do not claim to understand, but I see no contradiction here. The reference in the article [D. Pines (2002)] is also of high quality and supports this claim, although it talks of spin fluctuations instead of paramagnons, but these are more or less synonymous. Jähmefyysikko (talk) 18:48, 26 December 2021 (UTC)

Resistivity of Deionized Water?
Appears to be wrong: low by 100X. The ref is behind a paywall. Can someone with access verify it? The usual value for well-deionized water is 18e7 ohm-cm, not 18e5 71.37.36.149 (talk) 02:50, 6 March 2017 (UTC)

 * There is another source here, which does indeed give 18 MΩ·cm = 0.18×106 Ωm = 1.8×105 Ωm – the figure given in our article (as well as in purified water). You might have been confused by the choice of units – this article uses Ωm rather than Ω·cm. No such user (talk) 13:22, 6 March 2017 (UTC)

I was just looking at this table and noticed the same. DI water should be 1.8e7. — Preceding unsigned comment added by 67.159.168.22 (talk) 23:26, 3 June 2019 (UTC)

Disregard. I made the last comment, then attempted to update and was successful. — Preceding unsigned comment added by 67.159.168.22 (talk) 23:28, 3 June 2019 (UTC)

I noticed that the resistivity value was still incorrect (1.8e7 Ohm.m) in the table (but conductivity value was correct, hence the table was inconsistent). I have now updated the table to the correct resistivity value of 1.8e5 Ohm.m, which is the same as 18 MOhm.cm. EV1TE (talk) 14:03, 5 November 2019 (UTC)

Conductivity of air versus absolute or relative humidity
It is well known that experiments on static electricity work better under dry than humid conditions. The usual reason given is that humid air conducts electricity better than dry air, but if so does that depend chiefly on relative or absolute humidity? I would guess absolute, since that's what corresponds to the actual ratio of water molecules to air molecules. Another way of asking this question would be to ask, at a given absolute humidity, does the conductivity of air vary with temperature (which would change the relative humidity). I could not find tables of the conductivity or resistivity of air versus humidity in a cursory Web search, so I'm beginning to suspect that the answer may be more complicated, e.g. in addition to an effect on the conductivity of air, humid conditions (especially high relative humidity) may moisten the surfaces of otherwise insulating solid materials, making them more conductive, and thereby hastening the dissipation of charge otherwise than by actual conduction through the air. In any case, since the effect of humidity on conductivity of air is of great interest and practical importance, there should be a section on it, hopefully with a table or graph of reliable values, and/or an explanation of more complicated aspects such as those I conjecture here.CharlesHBennett (talk)

The conductivity of air (or any other gas) depends on a lot of factors. One very dominant factor is the background radiation as this is one of the major sources of free electrons in gases, which is also the dominant component for conductivity. Temperature, pressure, etc. affects free electron life-time and radiation absorption etc. Humidity affects surface resistivity of nearby insulating materials, which affects static electricicty measurements etc. Hence I do not think it is relevant to try and list precise values for conductivity for air or other gases, however some generic value +- 10x or so might be nice just for reference. EV1TE (talk) 14:14, 5 November 2019 (UTC)

de:Elektrische Leitfähigkeit
Why is there one page for two terms? that causes problems wit the interwiki links. --Manorainjan (talk) 16:24, 20 July 2017 (UTC)
 * Electrical conductivity de:Elektrische Leitfähigkeit
 * Electrical resistivity -> de:Spezifischer Widerstand

 * As explained at Wikipedia is not a dictionary, an article is about a concept or topic, not a word, so it is common for multiple very-closely-related terms to be defined in the same article. In many cases, it is not obvious whether articles should be merged or split, and there are debates / discussions about what to do. But each language's wikipedia is entitled to make its own independent decisions about which articles exist and what their scope is. If you think that the article should be split in two, you can propose that and make arguments for it, but if "German wiki did it differently" is your only argument, I think that's a very weak argument. Maybe this article should stay the same and German wiki should merge them! Or maybe different ways of organizing the information make sense in the different contexts, and problematic interwiki links are just an inevitable problem we'll have to accept. :-D --Steve (talk) 01:39, 21 July 2017 (UTC)

conductivity of graphene
Currently, graphene is listed as the material with the highest overall conductivity. Independent of whether this is correct or not, it is not supported by the cited press release. Actually, one of the scientists involved in the work, states in another news piece: "Other extrinsic sources in today's fairly dirty graphene samples add some extra resistivity to graphene, so the overall resistivity isn't quite as low as copper's at room temperature yet. However, graphene has far fewer electrons than copper, so in graphene the electrical current is carried by only a few electrons moving much faster than the electrons in copper."

In general, I would vote to remove graphene from this list as it is clearly an outlier. Comparing the properties of a (nearly perfect) single sheet of atoms against "real materials" with defects doesn't seem fair. --Leoteo87 (talk) 18:03, 20 November 2017 (UTC)

 * I agree, the 1e-8Ω·m =1μΩ·cm figure mentioned in the press release is described as a theoretical value of one contribution to resistivity by itself, not an all-things-considered prediction let alone a measurement. I would be happiest if it were deleted altogether, although I'm OK with it being replaced with a measured value.

 * I prefer deletion to fixing because it's a single-layer material by definition -- if you fill up a 3D volume with it then it stops being "graphene" -- and therefore is most usefully described by a sheet resistance not resistivity. Also, the resistivity varies dramatically with gate / doping (like other semiconductors / semi-metals). --Steve (talk) 22:22, 20 November 2017 (UTC)

Sodium
Hi, I see there is one table with Sodium and Lithium and their resistivity and res - volume products. But the Sodium is not present in the main table. I cannot find the main source for the sodium conductivity either or its dependence on temperature. 81.6.34.246 (talk) 17:55, 14 July 2018 (UTC)

"Conductor cross-section/volume ratio, at same conductance as copper" column
I deleted the rightmost column of the Resistivity density products table with the comment

 * delete rightmost column, i.e. conductivity vs copper, which is confusingly worded, redundant with the conductivity column, and somewhat off-topic for that section

Then put it back in with the comment "restored arbitrarily removed column".

I re-deleted again just now, but anyway I'm happy to discuss. Again, see my comment copied above for why I think it should be deleted. --Steve (talk) 16:48, 31 July 2018 (UTC)
 * Why does it hurt you to have related information there instead of emptyness? It's a factor that significant when you select better materials for resistivity density. Because as a side affect you get an increase in conductor cross section (so also volume). Besides it's calculated from and is a consequence of the same material properties resistivity density is calculated from. Also: if you don't like the wording, improve it (but I believe I've done so already). Dqeswn (talk) 17:03, 31 July 2018 (UTC)
 * Well, it hurts, being just arbitrary data that does not bring any new information to the reader. Next thing you know, we can add the value relative to aluminium, water or steel. Relative densities are pretty obvious from the next-to-last column, in the same order of magnitude. No such user (talk) 18:05, 31 July 2018 (UTC)

 * Emptyness is not always a bad thing. Textishardertoreadifyouleaveouttheemptyspacesbetweenwords, right? The limited resource is not space, but rather readers' time and attention span. A table with five columns is by default slightly easier to read and understand than a table with six columns, simply because there's less text to parse and digest. So that's the price we pay in adding a column. Do we get a benefit commensurate with that price? In this case, I say no.

 * This is the section on the resistivity × density product, which is relevant for people trying to minimize weight per conductance. So we can have columns saying the name of the material, the resistivity × density in SI units, the resistivity × density in easier-to-parse units, and the resistivity and density that allow readers to understand why the resistivity × density values are what they are. All those columns make sense, and are very valuable for the customers of that particular section, i.e. the people interested in how to minimize weight per conductance. Is it possible that some readers are interested in minimizing volume per conductance rather than weight per conductance? Sure, that's entirely possible. But they shouldn't be reading the resistivity × density section in the first place, they should be up looking at the main resistivity table, the one without density in it.

 * In reality, if I were personally building a mains electricity transmission line, I would be interested in (1) resistivity, (2) density, (3) price, (4) strength, (5) longevity, (6) availability, (7) lead time, (8) CTE, and dozens of other factors. It's not like adding your proposed column makes the difference between "having all relevant information necessary to build a mains electricity transmission line" and "not having all relevant information". It's just adding one more little bit of information out of the giant pool of relevant information. And the one bit it does add happens to be one that's already on the table! (in an only-slightly-harder-to-read form.) Do you think we should add dozens more columns to the table with all those other factors I mentioned? If not, why not? --Steve (talk) 18:12, 31 July 2018 (UTC)
 * It shows the fallout (in volume/cross section) from moving from standard copper to materials with better resistivity density. It's very relevant information.Dqeswn (talk) 13:27, 12 August 2018 (UTC)

Too technical
And since the first idea most people have access to is conductivity, rename to electrical conductivity and resistivity. -Inowen (nlfte) 02:57, 1 September 2018 (UTC)

 * We're all volunteers here. If you want the article to get better, you should try to help! :-D Writing the two words "too technical" and putting on the template is not quite completely useless, but it is very far from being as helpful as you could be. When I look at the article, as an expert, I see room for improvement (as always), but nothing jumps out at me as especially technical, i.e. far beyond what's necessary for talking about a technical topic, or far beyond what's typical for other wikipedia articles of this type. But I wouldn't know, would I? In fact it's almost impossible for an expert like me to create pedagogical material without very specific feedback from people trying to learn. Exactly which parts of which sections are too technical, and why? Did you find jargon-y words, and if so, which words, and can you try to find an easier-to-understand synonym? What exactly were you trying to learn that you couldn't learn, and what is your background? Did you look elsewhere for an explanation you could understand better, and if you found one, what was it?

 * I don't have a strong opinion about "electrical conductivity and resistivity" vs "electrical resistivity and conductivity". I personally learned about resistivity before conductivity, Inowen says they learned it the other way around, and I don't have any basis for guessing which of those is more common in the world. --Steve (talk) 20:40, 1 September 2018 (UTC)

Impedivity or impeditivity
This article uses a word (impeditivity) in the "Complex resistivity and conductivity" section. The word does not appear to be in use elsewhere (bar one or two links). Impedivity seems to be the term used in the links to academic publications. Wiktionary also has an entry for impedivity and admittivity. Neither appear in mainstream dictionaries, although you can find the word impeditive. Maybe that's why "impeditivity" was used in this article, for the sake of some kind of grammatical consistency. — Preceding unsigned comment added by 2001:BB6:7011:BB58:CC6C:940F:7C15:1528 (talk) 06:47, 15 October 2018 (UTC)

 * Thanks, I fixed it. It was probably just a simple mistake. --Steve (talk) 12:43, 15 October 2018 (UTC)

"Electrical conductivity or specific conductance is the reciprocal of electrical resistivity," but graphite is the most conductive while silver is the least resistive.
I'm just going to put this out here. If you sort the table by least resistivity you get different results than if you sort by highest conductivity. This conflicts the idea of them being inversely proportional. — Preceding unsigned comment added by 67.82.58.216 (talk) 01:26, 5 November 2018 (UTC)
 * Fixed talk2siNkarma86—Expert Sectioneer of Wikipedia 23:59, 5 November 2018 (UTC)

Inconsistency in values
In the table of resistivities and conductivities, the values for hard rubber and diamond (and possibly others) are inconsistent. Resistivity is the inverse of conductivity, but in both of those there's a factor of ten difference between their stated conductivity and their stated resistivity. Could someone verify which value is correct and fix the table? 104.167.148.149 (talk) 16:04, 5 July 2019 (UTC)

 * I agree, many values are inconsistent. It would be a quick fix to just open the values in excel and calculate one from the other, the issue is that one does not know which is correct and which is incorrect. Some values also seem to be confused with the older CGS-units Ohm.cm, but this article uses SI-units in Ohm.m. EV1TE (talk) 13:36, 5 November 2019 (UTC)

Actual testing
For your information, many years ago testing the VR on chlorinated paraffin and PVC was a common part of my role. The testing on PVC compounds in the form of a sheet about 4" x 4" was done using mercury. I am sure it's not done like that now! — Preceding unsigned comment added by 86.188.183.86 (talk) 14:51, 6 July 2020 (UTC)

GaAs has huge range for conductivity and resistivity
GaAs has huge range for conductivity and resistivity here (10^11) - presumably between intrinsic and doped, but Si and Ge only give one value so we should/could perhaps note its intrinsic (undoped) conductivity & resistivity ? GaAs says " high resistivity of 107–109 Ω·cm ....[9]" ie 105–107 Ω·m ? - Rod57 (talk) 12:40, 25 October 2021 (UTC)

Glass has wide range for conductivity and resistivity
Can we separate types of glass near the extremes of the 1:10,000 range given ? soda glass ? borosilicate glass ? lead 'crystal' ? - Rod57 (talk) 19:14, 25 October 2021 (UTC)

§ In metals: Distracting Newton's cradle GIF
Is it really necessary? I can't, for one, focus on reading the text with that so entertaining/distracting never-ending GIF. --TwainNeverSaidThat 15:58, 20 March 2022 (UTC)
 * I was the one who originally added it to the article, but I see (and empathize with) your point. I think it's a useful illustration of a mechanical analogy. Should we perhaps replace it with a proper video, such as the one to the right? No such user (talk) 16:19, 20 March 2022 (UTC)

 * I didn't want the illustration removed, if you were thinking that. Yes, replacing it with a video sounds good. Thank you. --TwainNeverSaidThat 13:25, 21 March 2022 (UTC)

Article issues and classification
The article has a multitude of sourcing issues. The criteria #1 states; The article is suitably referenced, with inline citations. It has reliable sources, and any important or controversial material which is likely to be challenged is cited. #4 states, The article is reasonably well-written. Articles tagged as "needing clarification (October 2021) and "disputed statements" (October 2021) are not indicative of being "well written". Reassess article to C-class. --  Otr500 (talk) 02:49, 1 March 2023 (UTC)

I think we need a section dedicated to materials and their conductance. — Preceding unsigned comment added by Clepenji1150 (talk • contribs) 16:28, 20 March 2023 (UTC)

kappa is never used as a conductivity symbol?
The current version says kappa is used in EE for electrical conductivity. In my 30y career (not in EE but in physics/MSE and working closely with electrical engineers) I never witnessed that. I just googled EE textbooks and out of the 6 I looked at, 4 use the usual sigma and the other two never introduce a symbol for conductivity. On the other hand, kappa is routinely used to denote either thermal conductivity or relative dielectric constant (and for the latter, the usage is indeed common in EE and MSE, whereas in Physics epsilon might be more common). In the absence of specific references, I would argue using kappa instead of sigma may be so rare that it does not deserve being mentioned in wiki. (Of course, any property can be denoted by any letter in someone's work, that the author's choice and if it passes by a referee it does not automatically turn such a notation into a convention!) On the other hand, given the similarity of the names "(electrical) conductivity" and "thermal conductivity" and the widespread use of kappa for the latter, even suggesting to use kappa to denote the former is worrisome. Definitely there is no justification that the current version has "kappa=1/rho" instead of "sigma=1/rho" in the heading section, that is bordering vandalism. 157.93.254.201 (talk) 03:50, 30 April 2024 (UTC)
 * That you have made an effort to verify the claim about the use of kappa, and not met with success, surely justifies slapping a citation needed tag on the claim. I have reverted the change of sigma to kappa in the info-box. catslash (talk) 21:40, 4 May 2024 (UTC)