DOI: 10.17605/OSF.IO/FB7R6

Investigation of Metalbending in the Avatar Universe and Proposals for Its Geological, Chemical, and Material Based Mechanisms of Action

Cameron Kaminsky, University of Massachusetts at Amherst

Abstract may be directly correlated to an ion’s hydrated radius in aqueous solution. The In the universe of Avatar: The Last possibility for controlled manipulation of Airbender, the established explanation for metal oxidation state in this case is also earthbending of processed metals (so-called explored and is theorized to be possible for “metalbending”) is inconsistent with the Avatar. depictions in canon sources and does not provide a rationale that adequately describes Introduction many of the discipline’s abilities and limitations. This work endeavors to uncover In the canon of Avatar: The Last mechanisms which are consistent with Airbender and Avatar: The Legend of Korra, canon depictions and lore as well as metalbending is a sub-discipline of established scientific fact. Metalbending is earthbending developed by Toph Beifong in most likely enabled by the presence of metal 100 AG.1 For the following seventy years, oxides or other ceramic impurities either this skill, long thought to be impossible, was within a processed metal or on the surface. refined and eventually passed along by the This reasonably explains the inability for Beifong matriarch to countless students, sufficiently pure samples of precious metals where it became a—still rare—but well- to be bent, while simultaneously explaining known feat of earthbending.2 It is popularly the bendability of other metals regardless of estimated that one in 100 earthbenders are sample purity. It is also likely that sample naturally predisposed with the ability to homogeneity plays a role in the ease of metalbend.3 The canon explanation for the manipulation. As samples become more phenomenon of metalbending states that heterogenous on the macroscopic and earthbenders cannot bend pure metal and structural level they become easier for that the act of metalbending requires the earthbenders to manipulate. This assertion is sensing of impurities within the metal, consistent with observed material behaviors such as those involving metal meteorites and coal. Finally, the manipulation of chelated or 1 Spaulding and O’Bryan, “The Earth King.” aqueous metal ions is established to be 2 Di Martino, Konietzko, and Yang, The Promise, possible. The difficulty of this manipulation Part One. 3 Graham and Mattila, “Old Wounds.”

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which can themselves be bent.4 This materials. As stated above, the ability to explanation raises many questions that focus manipulate metal is possible courtesy of on the very essence and definition of impurities in solid metal, and platinum is the earthbending and, by extension, one metal continuously singled out as being metalbending. At its heart, it creates the unbendable. It is not known for certain if necessity for a geological, physical, or other precious metals like gold or silver can chemical rationale for what can and cannot be bent. There is some circumstantial be bent. evidence that bending gold may be possible; Another huge complication in the canon Kuvira is seen to crumple the Kyoshi Medal explanation arises from the fact that even the of Freedom, which appears to be made of most capable metalbenders are unable to gold.6 However, the medal may have simply bend platinum.5 Again, the canonical been a less precious core plated with gold explanation is reliant on impurities within and, as a result, this is not reliable evidence the metal being the target and active that gold can be bent. Another mention of component in the act of bending. It states possible gold bending originates in the that, in the case of platinum, these impurities teachings of Toph Beifong. During her years are not present because the metal is too pure teaching metalbending at her academy, Toph and, as a result, it cannot be bent. This on at least one occasion required students to explanation lacks supporting evidence and is practice metalbending on coins.7 Earth inconsistent with facts that can be deduced Kingdom currency is composed of copper, from canon sources. The remainder of this silver, and gold pieces, but it again seems work will endeavor to provide a series of unlikely that these coins would be pure explanations for the observations and metal. Perhaps the most significant piece of behavior of metalbending in canon sources evidence regarding gold’s bendability is not and attempt to coalesce a coherent and explicitly stated and may instead be inferred consistent mechanism for the action of from the metal’s absence. If gold were metalbending. It will present these theories unbendable—and is assumed to be more in context, establish the predictions made by abundant than platinum—surely it would be them, and discuss any limitations that the metal of choice to protect from bending currently exist in the models. for purely economical and logistical reasons. Instead, platinum is used widely for this Discussion purpose, implying that gold alone would not be sufficient to prevent bending. Again, this Assessing the Facts analysis requires many assumptions that complicate the theory. In reality, the To begin the discussion of earthbending, abundance of gold and platinum in the it is first important to assess all of the facts earth’s crust is almost identical, but gold which are presented by the canon source

6 Zwyer and Hendrick, “The Coronation.” 4 Volpe, Di Martino, and Konietzko, “The Guru.” 7 Di Martino, Konietzko, and Yang, The Promise, 5 Dos Santos and Ryu, Ki Hyun, “The Aftermath.” Part Two.

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production has historically been much The carbon found in coal is technically higher.8 Gold is also an extremely soft metal organic, and regularly takes the form of when pure, which could explain why it is large nonregular aromatic networks.13 Even not used for these purposes.9 At this point, if anthracite, the most heavily coalified form, evidence directly from the canon is the only is still considered organic. It does have a consideration, it remains unclear whether considerably reduced nitrogen, oxygen, and gold can be bent by even the most powerful hydrogen content compared to early-stage metalbenders. coalification products, and is defined by a It is widely stated that metal obtained more aromatized structure, but remains a from meteorites is much easier to bend than nonregular polymer distinct from inorganic refined metals. Suyin Beifong successfully carbon ceramics like graphite.14 Curiously, taught many students including Avatar coal bending is the only confirmed occasion Korra to metalbend by beginning with metal on which manipulation of organic carbon is meteorites.10 This is a valuable piece of observed. It is believed that in general only information due to the extensively inorganic carbon is bendable, yet for some documented composition and structure of reason, coal is an exception to this rule. metal meteorites.11 As with coal bending, crystal bending Other materials that are known to be will be pertinent to later discussion. The bendable include metallic mercury, coal, and practice of crystalbending is considerably mineral crystals.12 These all have important rarer than garden variety earthbending but is roles in defining the abilities and limitations still assumed to be significantly easier than of metalbending. As a liquid metal at room metalbending. Little is known about the temperature, mercury is unique, and crystals seen being bent, and although there knowing that it is bendable may provide appear to be at least two distinct varieties, useful insight into the mechanisms at play. It even this is unclear. The first is seen in the is unclear whether mercury is relatively Crystal Catacombs of Ba Sing Se, and there harder or easier to bend than more mundane is little information regarding its processed metals. Coal bending is composition besides apparent apparently a beginner or intermediate level phosphorescence (or luminescence) and its earthbending form that has important pale green color.15 Due to the similarity in implications considering coal’s ancient appearance (Figure 1), there is a possibility biological origin and high carbon content. that these catacomb crystals are in fact jennamite, the other mineral crystal which is observed to be bendable.16 For further 8 Haynes, CRC Handbook of Chemistry and Physics, 97th ed.; Barbalace, “Periodic Table of Elements.” EnvironmentalChemistry.Com. 9 Samsonov, “Mechanical Properties of the 13 Malvadkar, Forbes, and McGurl, “Coal Resources, Elements.” Formation Of.” 10 Graham and Mattila, “Old Wounds.” 14 Orem and Finkelman, “9.8 - Coal Formation and 11 Wasson, Meteorites. Geochemistry.” 12 Zwyer, Hendrick, and Hamilton, “Venom of the 15 Di Martino and Ehasz, “The Crossroads of Red Lotus”; Di Martino and Ehasz, “The Crossroads Destiny.” of Destiny”; Filoni and Hubbard, “Imprisioned.” 16 Di Martino, The Legend of Korra, 2018.

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speculation on the composition of jennamite, and survival since at least 310 BG.18 Desert see Additional Information. sand is primarily silicon-based as well and is composed overwhelmingly of quartz grains

Defining Earthbending with the chemical formula SiO2, silicon dioxide. Quartz is the second most abundant Before any meaningful discussion may mineral in the earth’s crust.19 This seems to be had about the intricacies of earth- and indicate that silicon-based minerals are metalbending, it is necessary to define what commonly bendable. Although this may not constitutes earthbending, and what an be a steadfast rule, it is a solid starting point. earthbender can manipulate. Using a Many metal oxides such as aluminum, geocentric definition to outline this problem calcium, magnesium, and iron oxide form a is tempting, but that line of thinking is considerable amount of the material found in recursive and flawed. As is demonstrated by the Earth’s crust as well (Figure 2).20 Of meteorite bending, a metal or mineral does these, iron oxide is particularly interesting. not necessarily have to originate on Earth to The iron oxide most often found in Earth’s be bendable. Not only does this mean that crust is in the form of ferric oxide, Fe2O3, terrestrial origin is not a factor in defining and more rarely as ferrous oxide or 21 bendability, but it implies a dependence on magnetite (FeO and Fe3O4, respectively). material identity instead of origin. This By weight, iron is the fourth most common gives hope for a definition of bendable element in the Earth’s crust.22 It seems materials which is independent of the fitting then that metal oxides in general sample’s place of origin. could be bent by earthbenders. Although While terrestrial origin of a material is abundance alone is not a valid method of not sufficient evidence to prove its justification, the chemical and structural bendability, it can be used to investigate similarities to other bendable minerals and what compounds or mixtures are likely to be oxides seem to indicate that the possibility is bendable based on their ubiquity in indeed real. commonly bent materials. Investigating These compounds, as well as the what constitutes the rocks and earth being majority of other materials observed to be bent can reveal what chemical and bent can be defined as ceramics. In the field mineralogical structures are likely to be of materials science, a ceramic is a bendable. For example, the majority of crystalline or amorphous network solid with Earth’s crust is composed of feldspars, ionic or covalent bonds that contains a metal silicon-based minerals also containing or metalloid. The properties of ceramics can aluminum and oxygen.17 In addition, it is vary greatly, but minerals, inorganic known that the discipline of sandbending 18 has traditionally been used by tribes in the Si Yee and Di Martino, Avatar, The Last Airbender. 19 Anderson and Anderson, Geomorphology. Wong Desert for transportation, defense, 20 Rudnick and Gao, “3.01 - Composition of the Continental Crust.” 21 Greenwood et al., Chemistry of the Elements. 17 Rudnick and Gao, “3.01 - Composition of the 22 Morgan and Anders, “Chemical Composition of Continental Crust.” Earth, Venus, and Mercury.”

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crystals, and metal oxides would all be alloy with a carbon content under 2%.23 classified under this umbrella. The only Bending of this alloy appears to be common earthbending material which would consistent with the canon explanation since not be defined as a ceramic is coal, due to its inorganic carbon manipulation is predicted lack of a continuous covalent network. As a to be possible, and even most—if not all— result, earthbenders can be thought of earthbenders can easily bend coal. In the generally as ceramic benders, though case of steel, the “pieces of earth” or obviously their abilities are not limited “impurities” that metalbenders feel and solely to this. Perhaps there is a component manipulate are the inorganic carbon of earthbending which involves polymers particles of the alloy. This satisfies the like coal. In beginning to think about this explanation and depiction of Toph’s first question and the goal of defining time metalbending, assuming the cage she earthbending, the complexity and difficulty bent was made of steel or another iron- in justifying and explaining metalbending carbon alloy. She was able to sense the may be perceived. In fact, it may be easier to carbon particles in the alloy, then isolate and explain the mechanism of metalbending due manipulate these (Figure 3). In sufficiently to its relatively small domain of materials impure samples of metal, microscopic compared to earthbending, which contains ceramic impurities like silicates, sulfides, much more variety and depth to its observed and phosphates would fill the role of these action. carbon particles, enabling bending as well. This could explain why the “pieces of earth” Debunking the Canon explanation became commonplace; Toph had no experience bending other metals at With most of the pertinent facts this point and, as a result, generalized her collected, the process of examining the experience with steel when describing canon explanation for metalbending can metalbending as a whole. begin. The “pieces of earth” referenced by The canon explanation quickly becomes canon sources clearly indicate that chemical nonsensical when other metals are impurities in the metal are the active examined. At its core, the reliance on component in bending. Though seemingly platinum’s purity as the standard for bending innocuous, this is a necessary term to potential is flawed. Firstly, and most explicitly define, as imperfections in the obviously, platinum is not inherently more crystal structure of a metal may also be or less pure than other processed metals, as called “impurities” in certain fields of study. its purity relies on the techniques with which The similarity between the two is purely it was produced. If purity is the sole defining colloquial; only chemical impurities are characteristic that determines the bendability referenced explicitly by the canon. of a metal, why not simply produce—for The canon explanation is adequate at example—high purity aluminum for a rationalizing the ability for steels and other iron-carbon alloys to be bent. Steel is an iron 23 “Steel: Composition, Properties, Types, Grades, & Facts.”

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fraction of the cost of platinum?24 Platinum other metals, with practically no organic, is not miraculously easier to purify than any mineralogical, or otherwise solvated other given metal. Simply asserting that if a components.28 This is categorically metal is pure it is immediately unbendable is inconsistent with the notion that purity alone inconsistent with the depiction of the determines the potential for a metal to be abilities of metalbending in the world. bent. Even if purity was a determining factor in bendability, most of the platinum Inadequacy of Existing Theories observed can be assumed to be alloyed. Pure platinum metal is fairly malleable and as When investigating the rules dictating such is unsuitable for use in supports and metalbending, there are several tempting structurally integral components.25 Most of avenues to explore which are ultimately the platinum metal seen in canon sources is flawed in their justification or reasoning. part of heavy machinery or large structures First and foremost, one may be tempted to which suggests that this platinum is alloyed suggest that the abundance of a certain with another metal, otherwise the machines material in the Earth’s crust determines its would collapse under their own weight.26 ability to be bent. While this is not a Alloying involves the combination of two provably false claim, it provides a very different metals and, while this should still geocentric definition to a question that not permit bending on its own, seems to requires a generalizable answer. It is also raise questions about the canon’s important to recall that terrestrial origin of a overreliance on the purity of a metal. The material is not required for it to be bendable. canon explanation repeatedly states that the Relying on the composition of the planet as purity of platinum is the characteristic that opposed to physical, structural, and determines its lack of bendability, so the fact chemical properties of the material makes that these presentations are not solely the notion undesirable and unscientific. platinum indicates some level of Doing so implies a philosophical reliance of inconsistency. bending capabilities on human concepts and Furthermore, if purity is the sole definitions, which is unsuitable for this defining characteristic of a metal’s potential investigation and the subject as a whole. to be bent, mercury bending would likely be Another initially attractive approach is to prohibited. Mercury is a metal that tends to investigate the crystal structure of a material be very pure once isolated since most solid and search for any trend therein. While contaminants are less dense than the metal tempting on the surface, it quickly becomes and will float to and collect on the surface.27 apparent that this strategy is not a well- Other than these, the impurities detectable suited one for a multitude of reasons. In fact, even in minute amounts in mercury are all 28 Cherrier and Nalbantoglu, “Determination of Trace 24 Lindsay, “Very High Purity Aluminum.” Impurities in Mercury and Some High Purity Acids 25 Lagowski, Chemistry. by Spark Source Mass Spectrometry”; Elliott and 26 Ian and Hendrick, “Day of the Colossus.” Wilkinson, “The Effect of Base-Metal Impurities on 27 “Mercury (Metal): ” Encyclopedia.Com. the Surface Tension of Mercury.”

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this explanation would only be adequate in When considering tensile and yield investigating bending properties of regular strengths of metals pertinent to the crystalline minerals such as jennamite or discussion, (Table 1) it is important to note quartz, as the vast majority of earth and that these strength figures are extremely metal observed to be bent are not regular in generalized and will vary greatly based on their crystalline structure. the preparation, casting, and working of the The bulk of rock is an inhomogeneous metal in question. Tensile strength is the mixture of aggregated mineral particles, and maximum tensional force a material is able even highly processed metals are not to withstand before forming permanent local uniform in their crystal structure.29 Metals deformations and is likely the less important are comprised of grains (Figure 4) which of the two for this consideration.32 Yield can vary in size from a few micrometers to strength is the point at which a material over a millimeter depending on the metal begins to exhibit plastic deformation.33 This identity, purity, and methods of preparation, is more likely than tensile strength to be casting, and annealing.30 The lack of a single important in the alterations that commonly crystalline structure in metals prohibits result from bending. As outlined in the table, examination of the crystal structure as a platinum is a fairly malleable metal, on par primary source of physical properties. Grain with cast iron and much more malleable size has a significant effect on material than steel—both of which are bent properties in refined metals and, beyond extensively. Even stronger platinum alloys this, the physical properties of a metal vary a only have yield points in the mid-200s MPa, great deal based on its environment, even if whereas properly treated steels can possess the morphology remains unchanged.31 strength figures in the 1000s of MPa.34 If Since metalbending is ultimately a tensile or yield strength were an important macroscopic physical process, perhaps factor in determining bendability, platinum investigating characteristics of a metal such should be one of the easier metals to as tensile strength and yield strength could manipulate. Thus, it can be concluded that, net useful information? Again, this is a although material strength may or may not tempting and logical idea. If bending is a play a role in the difficulty with which a mechanical act that follows the same rules material can be bent, it definitely cannot be as conventional physical processes in the the sole determining factor in a metal’s classical sense, the strength of a material ability to be bent. There is obviously a should determine—at least in part—how remaining factor or set of factors that are difficult it is to bend. much more influential in that regard.

29 Cipriani, The Encyclopedia of Rocks and Minerals. 30 E04 Committee, “ASTM E112-13, Test Methods for Determining Average Grain Size”; Res et al., 32 “Tensile Strength: Definition, Unit, & Facts.” Grain Size in Cast Gold Alloys. 33 Dieter, Mechanical Metallurgy. 31 Wright, “Materials Science and Engineering. An 34 “The PGM Database”; “Online Materials Introduction, ” 2d ed. Information Resource - MatWeb.”

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Proposal of New Theories on the order of hours to react.38 By comparison, steel and iron will both begin to I. Oxidation and the Passive Layer oxidize the moment they are exposed to Theory oxygen, even at atmospheric pressure. Even aluminum, which notably resists corrosion, To develop a new set of theories readily forms an oxide layer upon exposure regarding natural rules which regulate to the atmosphere.39 metalbending and earthbending, it is Before proceeding further, it is necessary important to search for any correlations to define the requisite vocabulary. When between observations made and existing referring to platinum, gold, and other metals data. The most important observation of and alloys, “oxidation” and “corrosion” metalbending that requires explanation is cannot be used interchangeably. Many platinum’s inability to be bent. In attempting metals and alloys such as iron and steel to define what makes platinum unique, there oxidize and corrode, while others such as is one key characteristic that immediately chromium and aluminum oxidize but are stands out: Its inertness. Platinum is a strikingly resistant to corrosion. Oxidation is remarkably unreactive metal, even relative a purely chemical transformation in which a to other precious metals such as gold. metal undergoes a chemical reaction with an Although the reactivity series of elements is oxidizing species—most commonly oxygen inconsistently defined and lacks gas in the atmosphere. Corrosion is the standardization between sources, platinum is physical weakening and change in other universally ranked as the least reactive properties which results from oxidation. metal.35 For the purposes of this paper, the Oxidation is a change at the chemical level, most important application of this whereas corrosion is a macroscopic physical information is that platinum will oxidize at a process that may or may not result from this much lower rate than even gold or silver. chemical change depending on the system in Platinum oxide does exist and is used as a question. catalyst in many hydrogenation and Corrosion prevention can commonly be dehydrogenation reactions.36 Despite this, achieved through the formation of a “passive the formation of natural platinum oxide on layer” in a process called passivation.40 The metal is more complicated, and the line formation of a passive layer is a common between bound and free oxygen molecules is technique employed in corrosion-resistant often blurry.37 It can only be formed reliably alloys. One common type of passivation on solid platinum metal under close to relies on a naturally formed surface oxide atmospheric conditions if given a timescale layer to protect the pure metal underneath

38 Fantauzzi et al., “Growth of Stable Surface Oxides on 111Pt at Near-Ambient Pressures.” 35 Greenwood et al., Chemistry of the Elements. 39 Agarwala and Fort, “Nature of the Stable Oxide 36 Nishimura, Handbook of Heterogeneous Catalytic Layer Formed on an Aluminum Surface by Work Hydrogenation for Organic Synthesis. Function Measurements.” 37 McCabe, Wong, and Woo, “The Passivating 40 “Surface Passivation - an Overview,” Oxidation of Platinum.” ScienceDirect Topics.

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from reacting with the atmosphere (Figure to its low thickness, much like platinum.45 5). For platinum and gold, this passive layer Silver oxidizes to a considerably higher is slow to form at normal atmospheric degree than either gold or platinum, and as conditions, and even then is essentially such should most likely be bendable. limited to the outer layer of atoms It may seem logical to conflate this exclusively.41 As such it is extremely thin, theory with the canon explanation criticized generally on the order of one to three previously, however, there are many key Angstroms regardless of oxygen pressure or differences. A small but meaningful temperature, and does not grow any larger distinction is that this layer of metal oxide is under extended timescales.42 This is on the outside of the metal, rather than compared to stainless steels, which almost dispersed throughout. Due to this, it does not immediately form passive layers between rely on metal purity as a defining factor in 10-30 Å, and aluminum, which will form an bendability. This is the main sticking point oxide layer of up to 50 Å.43 where the original explanation goes wrong. If metal oxides are able to be bent by According to the canon, a slightly impure metalbenders, which seems likely, then the sample of platinum would be bendable while “bending active” portion of a processed an extremely pure sample of iron would not. metal may simply be these oxides present on With this new explanation, even the purest the surface. This would explain why sample of iron or copper or aluminum platinum cannot be bent: Its passive layer of should be bendable by extremely gifted platinum oxide is simply too small or earthbenders due to its unavoidable oxide entirely nonexistent, and as such cannot be layer. This is more in line with the behavior effectively utilized to bend the bulk metal. and logic presented in canon sources. It Definitive knowledge of gold’s bendability successfully explains the phenomenon of would be useful in evaluating this theory; both pure platinum and derived alloys being gold is another remarkably unreactive metal, unbendable without relying solely on purity only marginally more reactive than as an explanation. One noteworthy platinum. Although it does form oxides, complication that arises from this theory is there is currently evidence that this only the implication of dependence on surface occurs in appreciable quantities at area to volume ratio if bending is thought to atmospheric pressure and temperature when be described by traditional mechanics. ozone is present.44 As a result, even though Without a clear sampling of the relative gold is thought to have a passive layer, the difficulties inherent in bending samples of bulk metal should most likely be unbendable differing geometries, evaluating the validity according to this Passive Layer Theory due of this prediction is impossible.

41 Cuff, “Passivation Layer on Noble Metals.” 42 Fehlner, “Low Temperature Oxidation, the Role of Vitreous Oxides.” 43 Olsson and Landolt, “Passive Films on Stainless Steels - Chemistry, Structure and Growth.” 44 Cuff, “Passivation Layer on Noble Metals.” 45 Müller and Löw, “Passivity of Gold.”

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II. Dependence on Macroscopic and metal (Figure 6). These well-defined phase Microscopic Heterogeneity boundaries in the bulk meteorite arise from the propensity for iron-nickel alloys to form One of the major shortcomings of the different mineral phases depending on Passive Layer Theory in isolation is the lack deposition conditions and cooling timescale, of an explanation for the relative ease with as well as the nickel content of the sample.47 which metal meteorites are bent. Even if The different phases are most commonly the there were high levels of silicates or other minerals kamacite and taenite, along with bendable impurities in these meteorites, that other trace minerals such as the sulfur- could not singlehandedly account for the containing schreibersite and troilite.48 These superlative ease with which metal meteorites different phases can have dimensions are able to be bent compared to steels and ranging in size from under 200 μm to over cast iron. In addition to the Passive Layer 3.3 mm.49 If sample heterogeneity is a Theory, there must be other factors parameter that affects bendability, then governing the act of metalbending. One meteorites should certainly be easier to bend theory which seems to adequately explain due to their extensive irregularity in this phenomenon while also tying into crystalline and chemical structure; in this existing knowledge about earthbending is regard, they are similar to bulk earth and that sample heterogeneity on both the atomic rocks. and macroscopic level reduces the difficulty Application of this theory may also aid of earthbending and metalbending. In other in explaining the bendability of coal. As words, material identity determines if stated previously, coal bending is the sole bending is possible, and the heterogeneity of occasion on which manipulation of organic a sample plays a role in how difficult the carbon is observed. Coal is a polymer but is bending is. This proposal not only provides nonregular in its structure due to its a rationale for the increased bendability of biological origin.50 It is possible that the metal meteorites compared to other metals, irregularity in coal’s structure explains its but is also compatible with the Passive ability to be bent; it is much less uniform Layer Theory, and the two work in than most minerals and is considered a complement to fill in gaps that exist in sedimentary rock by the ASTM.51 This isolation. nonregularity of the polymer and lack of Metal meteorites are almost exclusively structural heterogeneity could explain coal’s composed of a metal known as meteoric iron, an iron alloy which generally possesses 47 Goldstein, Scott, and Chabot, “Iron Meteorites.” a low cobalt content and a nickel content 48 Paneth, “The Discovery and Earliest Reproductions between 5% and 25% by mass.46 of the Widmanstätten Figures”; Burke, Cosmic Structurally speaking, they are extremely Debris. 49 Shirley and Fairbridge, Encyclopedia of Planetary easy to recognize and classify thanks to Sciences. distinctive Widmanstätten patterns in the 50 Chadwick, Highton, and Lindman, “6 - Coal Conversion Technologies.” 51 Malvadkar, Forbes, and McGurl, “Coal Resources, 46 Wasson, Meteorites. Formation of.”

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apparent ease of bending despite its organic mineral crystals.52 In these depictions, it nature. appears that crystalbending is not In defining this theory, it is necessary to significantly more difficult than generic also define the notion of heterogeneity. In earthbending, as Avatar Aang was able to this case, both chemical heterogeneity as manipulate crystals while still a novice well as a compositional heterogeneity on the earthbender. This is not at all consistent with macroscopic level are important. Most the predictions made by the heterogeneity generic earth and rocks as well as metal theory. Pure crystals are the ultimate meteorites would be considered standard in chemical and structural macroscopically heterogeneous since they homogeneity, and thus would be predicted are comprised of different minerals and by the heterogeneity theory to be more grains compacted together. On the other difficult to bend. If they can be manipulated hand, a material like glass would be by earthbenders who do not seem overly considered homogenous compositionally, skilled such as a novice Aang and Jargala but heterogeneous on the level of chemical Omo, then the heterogeneity theory conflicts structure. A pure sample of silica glass is a with the facts as presented.53 Currently, this silicon dioxide network solid which is not discrepancy remains unresolved. Although crystalline and has an amorphous nonregular unsatisfying, this working model is subject crystal structure. It is all the same chemical to change—as all theories are—and requires formula, SiO2, but there is no regular pattern more refining before it is consistent with all with which the structure is repeated over in the facts presented. At this point, there is 3D space. If this heterogeneity theory is simply not enough information to either correct, the bending of a sample of pure explain the counterintuitive bendability of silica glass would be expected to be easier crystals or to refine the theory to allow for than an equivalent sample of quartz even this behavior. Any number of other factors though the chemical composition is the same such as crystal composition, doping, or in both. Similar to silica glass, refined lattice structure could play a role, but metals should be mostly homogenous without concrete proof and knowledge of the compositionally but will not have an entirely crystals’ identity, these proposals will regular crystal structure. There will be remain as speculation. differences in the crystal structure and The two theories presented thus far are orientation of grains, but the metals will still by no means mutually exclusive and can be be far more regular when compared to rocks applied in tandem to describe the behavior or ores. observed and recorded regarding It is necessary to acknowledge that this metalbending. When considering the effect theory is incomplete, and in fact, seems to that heterogeneity has on bending be directly contradicted by the existence and characteristics, most of the distinctions made depictions of crystalbending. On multiple occasions, earthbenders are seen 52 Di Martino and Ehasz, “The Crossroads of manipulating what appear to be solid Destiny”; Lioi and O’Bryan, “The King of Omashu.” 53 Di Martino, The Legend of Korra, 2017.

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regarding metals and alloys already cited III. Regarding Aqueous and Chelated would be relatively unaffected by the Metal Ions: The Mercury Problem application of this new theory. Grain size in refined metals varies greatly based on small One remaining action of metalbending differences in the preparation and working which is not addressed satisfactorily by of the sample but remains more or less application of either theory presented thus consistent from metal to metal. Edge cases far is the ability for metalbenders to remove with excessively small or extremely large mercury from a person’s body. Suyin grains may—or may not—be significantly Beifong and Avatar Korra are shown affected by the application of this theory; accomplishing this feat in 171 AG and 174 without a testable hypothesis it is not AG respectively, and it has implications that possible to weight the two theories and are unexpectedly complicating.54 pinpoint an empirical point where one Unfortunately, many of the questions raised overtakes the other in importance. Even with by and regarding this feat are unable to be these small caveats and unknown quanta, it answered without the ability to collect more is expected that the heterogeneity theory information on the subject; there is simply should not play a very important role in the not enough evidence regarding this incident distinctions between metals, but will have a or the bending of mercury as a whole much more pronounced effect when presented in canon sources. As such, any considering materials whose grains are more hypotheses presented including those below distinct in composition such as meteorites, must in part be manufactured of educated or materials which are completely guesswork and will unavoidably leave gaps homogenous throughout, like crystals. in their explanation. The two models presented can and When introduced to the circulatory should be applied in a complementary system and other bodily tissues either via manner, where the impacts of passivation inhalation or absorption through the skin, and oxidation are more important when used metallic mercury is quickly oxidized to the to define refined metalbending interactions considerably more soluble Hg2+ ion by and the homogeneity proposal is more enzymatic action.55 Once dissolved within applicable to explaining specific behavior the body, the mercuric ion may be bound by observed in other materials such as any strong enough nucleophiles due to its meteorites. Although both are ideally small hydrostatic radius. One particular generalizable and should be universally interaction that is responsible for much of applicable, they are most useful when the damage associated with mercury applied in the manner described which poisoning is the affinity of the ion for thiol should adequately explain recorded groups and selenols, specifically those in the phenomena and not conflict with each other class of proteins known as thioredoxin while maintaining a simple enough model to be useful. 54 Zwyer, Hendrick, and Hamilton, “Venom of the Red Lotus”; Heck and Mattila, “The Calling.” 55 “Toxicological Profile for Mercury.”

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reductases (TrxR).56 The selenocysteine mercury administration through the skin. residue in TrxR lends the enzyme a Without any conclusive scientific data on significantly higher reactivity with its the matter, definitively predicting the preferred substrates, but also induces a behavior of the mercury is impossible; higher affinity for mercuric ions compared however, it is reasonable to assume that the to thiols alone.57 Through its binding to quantity of mercury seen introduced to these residues (Figure 7), the mercuric ion Korra’s system could not possibly be totally inhibits TrxR, which is responsible for oxidized and dissolved in a timescale under (among other things) the reduction of an hour.61 This is important to note since it antioxidant molecules back into their active means that both metallic mercury and metal forms.58 Without the continuous renewal of ions were present for Suyin’s aid. these antioxidant compounds, oxidative It is theorized that Suyin was only able damage to cells is more prevalent. This to detect this unoxidized mercury metal, not damage is particularly concentrated in the the dissolved metal ions; in fact, the only brain, where oxygen consumption is high. person ever shown capable of this latter feat The subsequent oxidative damage to the without tutoring was her mother, Toph.62 If brain causes many of the neurological the mercury which Suyin was able to symptoms associated with mercury remove in 171 AG had not yet been oxidized poisoning. Luckily for Avatar Korra, the and dissolved into Korra’s bloodstream or sheer volume of mercury administered may chelated by any biomolecules, this means have played a role in hindering its own that any and all of the dissolved metal ions absorption into the bloodstream, as a similar which had already been oxidized remained effect is known to occur when elemental in the Avatar’s body. Perplexingly, the sheer mercury is administered intravenously.59 quantity of metal which remained should This may have been a contributing factor have been effortless to detect for such a that enabled her survival for a long enough proficient metalbender even when dispersed time before emergency aid could be throughout a volume as large as a body, yet administered by Suyin. neither Suyin nor Korra could detect the Percutaneous absorption of metallic metal at any point in the next three years, mercury is normally limited to a very slow even though the Avatar’s body obviously rate.60 As such, there is little in the way of still contained several kilograms of mercury scientific literature regarding high volume ions. Thus, evidence seems to indicate that detecting—let alone bending—metal ions is 56 Carvalho et al., “Inhibition of the Human extremely difficult, even in comparison to Thioredoxin System: A Molectular Mechanism of Mercury Toxicity.” other feats in the already advanced school of 57 Gromer et al., “Active Sites of Thioredoxin metalbending. Reductases.” Avatar Korra performed her own 58 Linster and Schaftingen, “Vitamin C Biosynthesis, Recycling and Degradation in Mammals.” metalbending bioremediation in 174 AG 59 Clarkson and Magos, “The Toxicology of Mercury and Its Chemical Compounds.” 60 Hursh et al., “Percutaneous Absorption of Mercury 61 Sigel and Sigel, Metal Ions in Biological Systems. Vapor by Man.” 62 Heck and Mattila, “The Calling.”

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and, in the process, finally proved that impede or prohibit manipulation, and as a aqueous and chelated metal ions can be bent result this metalbending form may only be by sufficiently strong metalbenders. Even if possible with heavier metal ions with Suyin had left minute traces of metallic smaller hydrostatic radii which are rarely mercury behind in 171 AG it would all have present in biological systems or everyday been oxidized and dissolved within the body life. over the next 3 years, so all of the mercury It is currently unclear how exactly the removed in 174 AG certainly originated in Avatar was able to remove the mercury from the form of the mercuric ion. Though this the chelated biomolecules but it appears that manipulation of aqueous and chelated metal in the process she reduced it back to its ions is apparently extremely difficult even oxidation state of 0, as the mercury removed for very skilled metalbenders it must be from her body is clearly in its metallic possible as demonstrated in this instance. unoxidized form (Figure 8). Normally, Since Avatar Korra and Toph are the sole mercury ions can be converted back to their known practitioners, it seems that bending metallic form through oxidation-reduction metal ions in solution or in one’s body is a reactions, but it is unclear what exact technique that approaches but does not equal chemical process occurred during the or surpass the difficulty of plate tectonics mercury’s removal from the Avatar. The manipulation, which is an Avatar level feat only occasion on which any school of of earthbending.63 bending is seen to be capable of controlling The implications of this ability are electrochemical change is the firebending broad, far-reaching, and could likely fill a sub-school of lightningbending, which deals separate paper multiple times the size of this with ionization and movement of electrons one. As of right now, the focus will be on within materials to induce charge gleaning any possible facts about the separation.65 If charge manipulation is a skill technique. It is possible that a metal ion’s exclusive to firebenders, perhaps only the hydrostatic radius and the ease with which it Avatar is capable of the observed reduction is manipulated are inversely correlated. In of mercury to its metallic form because of aqueous solution, a larger hydrostatic radius their ability to manipulate metal ions as well makes ions significantly less mobile and, as as ability in firebending. Even though Korra a heavy metal, mercury ions have a much is not a lightningbender, she may still have smaller hydrostatic radius than common been able to control the charge flow due to metal ions like potassium, magnesium, and the small scale, and especially because it sodium.64 This could explain why bending was within her own body. This prediction of these common biological ions is never could be tested if Toph was seen extracting observed; their large hydrated radii may the metal from Korra’s body. However, since she never actually removed the 63 Di Martino, Konietzko, and Yang, The Promise, mercury, it cannot be determined whether Part Three; MacMullan and O’Bryan, “Avatar Day.” she was capable of this conversion back to 64 Tansel et al., “Significance of Hydrated Radius and Hydration Shells on Ionic Permeability during Nanofiltration in Dead End and Cross Flow Modes.” 65 Spaulding and Ehasz, “Bitter Work.”

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the metallic form or not. The physical and actions of small amounts of oxides or other electrochemical implications of effectively additives present. becoming a human capacitor are most Currently, there is no way to reconcile certainly outside the scope of this paper but these two theories. That is not to say that may very well hold the key to explaining one or both are wrong, there is simply such this phenomenon observed in Korra’s little information from which to draw that mercury bending, assuming finely tuned any number of factors could be responsible control of charge manipulation is attainable. for the apparent bendability of the metal If this interpretation of the mercury mercury. For instance, it could simply be remediation events in 171 and 174 AG is caused by oxidized mercury species which correct and only extremely capable are not dissolved in the blood or tissue but metalbenders can manipulate metal ions in are instead still incorporated into the liquid solution, is it consistent with the already metal. This solution has no immediate proposed theories? For the most part, the mechanism by which it may be rationalized, answer to this question is yes, but there are it is simply one of many hypotheses which some areas of doubt involved. The Passive could be posited to explain this lack of Layer Theory mainly details the necessity agreement. Forming more accurate or for a metal to be in an oxidized compound in specific justifications for the apparent order for it to be bendable, which the bendability of supposedly pure mercury already oxidized mercury in the body would would require the ability to experiment and at least be arguably consistent with. The gather new data. Perhaps liquid metal Passive Layer Theory does not make any behaves differently and is for some reason predictions on the bendability of metal ions; more bendable than solid metal, even when its only major stipulation is that a metal lacking metal oxides or other bendable must be part of an oxidized compound. In all components. This proposition may hold technicality the mercury ions are consistent slightly more proverbial water, as it could be with this description; they are simply justified using the predictions of the solvated or chelated as opposed to being heterogeneity theory on the basis that liquid confined in a solid lattice. However, the mercury lacks an ordered crystalline unoxidized metal Suyin removed initially structure due to its liquid state of matter. from Korra in 171 AG as well as the metallic mercury which Korra herself Conclusion removed in 174 AG would not be predicted to be bendable by the passive layer theory or The investigation of earthbending and its any other mechanism discussed. This sub-discipline of metalbending has revealed mercury should be elemental, and thus far it a set of theories which may be applied in has been assumed that pure metals in discussion and analysis of metalbending oxidation state 0 are themselves unbendable abilities, and which are consistent and and are only able to be manipulated by the scientific in their application. First and foremost, most of the refined metals known

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to be bendable are able to be manipulated metalbending: control of oxidation and due to the unavoidable layer of oxidation reduction of metals—at least in one’s own which forms upon exposure to the body. These theories are for the most part atmosphere. The mechanism of action for consistent and may be applied without metalbending pure metals and alloys conflicting. The few areas in which they involves the manipulation of this oxide may lack agreement stem primarily from an layer. Platinum reacts slowly if at all with absence of supporting information and oxygen under atmospheric conditions and as should not be used in isolation to justify a result is predicted by this theory to be dismissing the validity of a component. unbendable if purified or slightly alloyed. Gold is similarly unreactive in the Additional Information atmosphere and is hypothesized to be unbendable as well. Sample homogeneity The following section is a collection of also appears to play a role in the relative miscellaneous side notes and applications of difficulty with which a material may be research that do not necessarily fit in the bent. Evidence indicates that samples which scope of the main paper but are valuable to are more heterogenous on the structural and explore nonetheless. Some lack sufficient chemical level are easier for earthbenders to facts to yield any useful discussion and thus manipulate. Although it is unlikely to be a are not quite fitting for a paper of this type, major factor with regards to bending refined and others require such a degree of metals, this theory can be applied in expansion and elaboration that placing them justification of the relative ease with which in the same category as the theories which metal meteorites are observed to be acted are the main focus of the paper would upon in comparison. It is, however, notably jeopardize the scope of an already long and inconsistent with depictions of sprawling document. While sources will crystalbending, a seemingly novice-level continue to be cited, this section can be earthbending sub-discipline of a very considered an extraneous portion of the homogenous material. Finally, it appears paper which contains observations and that the manipulation of metal ions either questions which are not necessarily pertinent free in solution or chelated by ligands is to the main discussion at hand but may be possible, but only for the most advanced useful as appendices to it. metalbenders. This technique is surrounded Jennamite is described as “rock candy” by uncertainty due to the infrequency of its by King Bumi of Omashu and accordingly is use and scarcity of its practitioners but is usually inferred to be some sort of evidenced to be possible all the same, and saccharine crystal.66 Notably, it is never the ability may be inversely correlated to an described this way again despite being ion’s hydrated radius. Its application by depicted many times. Organic crystals are Avatar Korra in the removal of mercury ions neither ceramic nor polymeric and thus, if from her own body presents the discussion this “candy” description is accurate, it would of a new Avatar level application of 66 Lioi and O’Bryan, “The King of Omashu.”

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be the only occasion on which organic or other bendable contamination from the carbon is observed to be bendable outside of body they are extracted from. coal manipulation. This seems highly The mercury left in Korra’s body after improbable and raises three distinct Suyin’s initial aid would be expected to possibilities. In the unlikely case that the gradually be excreted over the next 3 years crystal really is composed of sugars, then it with a half-life of approximately 30 to 60 suggests organic compounds can be bent if days.70 Judging by these figures Korra’s in a crystalline phase. If the crystal is not body should have already remediated made of sugars, this either casts doubt on the practically 100% of the mercury that had notoriously eccentric king’s “rock candy” been dissolved as the mercuric ion in her description, or indicates that the crystal is a body. Even when assuming a half-life of 60 relatively non-toxic inorganic salt or mineral days, only 0.001% of the original ions which tastes sweet to humans.67 Beyond should remain in her body after 1000 days. these speculations, definitive elucidation of The mercury ions which were deposited in jennamite’s composition is impossible. the brain have a very different story, One note which is useful to consider however. Mercury remains in the brain for regarding mercury bending is that the much longer, with an estimated half-life of Passive Layer Theory can be applied to the up to 20 years.71 Using this figure, first time mercury is seen being bent. When approximately 91% of the mercury in Ghazan initially oversees the administration Korra’s brain would remain unremediated of mercury metal to Korra it is presented in after 1000 days. Thus, when she bent the an uncovered bowl.68 Even in dry air and at remainder of the metal out from her body in room temperature, metallic mercury will 174 AG, practically all of it should have dull as oxides are formed on its surface. This come from her brain. Judging purely by the occurs regardless of purity and the oxides volume of mercury which was removed, it concentrate on the surface of the liquid due seems impossible for this to be true. That to surface tension.69 This explanation much mercury solely in Korra’s brain would becomes more difficult to apply to all the surely be fatal. This implies that somehow other times mercury is seen being the process of mercury remediation and manipulated, as on these occasions it is excretion from the body must have been being freshly exposed to the atmosphere. In slowed. Perhaps the subsequent paralysis those cases, the oxidation implied to be which resulted from her poisoning impacted present would be required to originate from blood flow or other anatomical parameters another source such as trace mercury ions that impeded the remediation of mercury still unreduced back to their metallic state, from her body? Judging by Toph’s bending motions during her attempt to extract the mercury herself, there seems to be a high 67 Basbaum et al., The Senses. 68 Zwyer, Hendrick, and Hamilton, “Venom of the Red Lotus.” 70 Park and Zheng, “Human Exposure and Health 69 Elliott and Wilkinson, “The Effect of Base-Metal Effects of Inorganic and Elemental Mercury.” Impurities on the Surface Tension of Mercury.” 71 Ibid.

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amount of mercury remaining in Korra’s construction and would explain the city’s legs—which were paralyzed for a time. This proximity to the strait, as well as the could be interpreted to lend support to this apparent high abundance of platinum in the hypothesis. world. It is difficult to write a paper of this Finally, this paper would be incomplete nature without talking about platinum if it did not briefly mention the application abundance in some way. On the surface, of these theories to the mystery of Avatar platinum appears to be much more abundant Kyoshi and Lao Ge’s long lives. Avatar in the canon universe; Zaofu alone was Kyoshi’s extremely long lifespan of 230 protected by domes which likely contained years is noteworthy and is shrouded in more platinum than has been mined in the mystery. The sparse information regarding it history of our earth.72 Where did all this is taught to her by Lao Ge, an earthbender platinum come from? Simply stating that who served as her spiritual mentor. In his platinum is naturally more abundant in the teachings to Kyoshi, he states that: canon universe may answer the question but is a vague and impossible to support Aging is really just your body falling hypothesis. There is another, more specific apart, on the smallest, most invisible explanation that fits neatly into the history, levels, and neglecting to put itself geography, and lore of the Earth Kingdom. back together. With the right mental Zaofu is located fairly close to the Chin focus, you could take an inventory of peninsula and Kyoshi island (Figure 9). In your own body and place each little 270 BG, this was the site of Avatar Kyoshi’s piece that’s not where it should be manipulation of plate tectonics to separate back into the correct order.75 the island from the mainland.73 There is evidence that most of the large platinum This vague explanation of the aging deposits in the earth’s crust originated in the process could be interpreted as a less mantle due to platinum’s siderophilicity scientific description of the process of which caused it to “sink” in the early stages oxidative damage to the body, which is a of planetary formation.74 It the author’s common theory regarding the causes of theory that in the process of moving the aging.74 It hypothesizes that symptoms of continental plates, a large section of aging are due largely to oxidative damage to previously buried mantle was exposed in the an organism’s cells and biomolecules which Kyoshi Strait. This new mantle material—if accumulates throughout an organism’s rich in platinum—would have provided the lifetime. If this interpretation of Lao Ge’s raw material necessary for Zaofu’s wisdom is accepted, it could be construed that control of the oxidation in one’s own 72 Anderson, “How Much Platinum Is in the World?”; body as predicted from Korra’s mercury Di Martino, The Legend of Korra, 2015. 73 MacMullan and O’Bryan, “Avatar Day.” bending is responsible at least in part for 74 Richardson and Shirey, “Continental Mantle Kyoshi’s long life. While this connection is Signature of Bushveld Magmas and Coeval Diamonds”; Albarede, “Siderophile Elements”; Anderson, “Chemical Composition of the Mantle.” 75 Yee and Di Martino, Avatar, The Last Airbender.

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tempting to make, the truth is most likely Albarede, Francis. “Siderophile Elements.” significantly more complicated than that. In Encyclopedia of Astrobiology, eds. Firstly, it was hypothesized that an ability in Muriel Gargaud, Ricardo Amils, José firebending is required to achieve precise Cernicharo Quintanilla, Henderson control of the charge flow required in James Cleaves, William M. Irvine, oxidative control, and Lao Ge is an Daniele L. Pinti, and Michel Viso, 1510. earthbender. Secondly, the assertion that Berlin, Heidelberg: Springer, 2011. oxidative damage to the body’s https://doi.org/10.1007/978-3-642- macromolecules is the sole cause of age- 11274-4_1445. related physiological changes is a bold Anderson, Don L. “Chemical Composition assertion and one which is not supported by of the Mantle.” Journal of Geophysical the bulk of scientific literature. Aging is a Research 88, no. S01 (1983): B41. vastly complicated process that is nowhere https://doi.org/10.1029/JB088iS01p00B close to being fully understood. It is the 41. culmination of chemical and biological Anderson, James. “How Much Platinum Is mistakes, dysfunctions, design limitations, in the World?” SD Bullion (31 Aug. and a host of yet undiscovered root causes 2019. https://sdbullion.com/blog/how- that accumulate over the course of a much-platinum-is-in-the-world. lifetime.76 It is simply not a process which Anderson, Robert S., and Suzanne P. may be simplified to this degree. Finally, Anderson. Geomorphology: The neither Lao Ge nor Kyoshi were Mechanics and Chemistry of metalbenders, which eliminates the Landscapes. Cambridge: University possibility of controlling the metals within Press, 2010. the nervous system or in the active sites of Barbalace, Kenneth. “Periodic Table of proteins, which would presumably be an Elements. ” important part of monitoring and reversing EnvironmentalChemistry.Com, 2020. oxidative damage to the body. https://environmentalchemistry.com/yog i/periodic/. References Basbaum, Allan I., Akimichi Kaneko, Gordon G. Shepherd, and Gerald Agarwala, Vijay K., and Tomlinson Fort. Westheimer, eds. The Senses: A “Nature of the Stable Oxide Layer Comprehensive Reference. Formed on an Aluminum Surface by Amsterdam and Boston: Academic Work Function Measurements.” Surface Press, 2007. Science 54, no. 1 (1 Jan. 1976): 60–70. Burke, John G. Cosmic Debris: Meteorites https://doi.org/10.1016/0039- in History. Berkeley: University of 6028(76)90087-X. California Press, 1991. Carvalho, Cristina M. L., Eng-Hui Chew, Seyed Isaac Hashemy, Jun Lu, and Arne

76 Mc Auley et al., “Modelling the Molecular Holmgren. “Inhibition of the Human Mechanisms of Aging.”

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Thioredoxin System A Molecular Promise, Part One. Vol. 1. 3 vols. Dark Mechanism of Mercury Toxicity.” Horse Comics, 2012. Journal of Biological Chemistry 283, no. ———. The Promise, Part Three. Vol. 3. 3 18 (May 2, 2008): 11913–23. vols. Dark Horse Comics, 2012. https://doi.org/10.1074/jbc.M710133200 ———. The Promise, Part Two. Vol. 2. 3 Chadwick, M. J., N. H. Highton, and N. vols. Dark Horse Comics, 2012. Lindman, eds. “6 - Coal Conversion Dieter, George Ellwood. Mechanical Technologies.” In Environmental Metallurgy, 1986. Impacts of Coal Mining & Utilization, https://www.mheducation.com/highered/ 105–155. Amsterdam: Pergamon, 1987. product/mechanical-metallurgy- https://doi.org/10.1016/B978-0-08- dieter/9780070168930.html. 031427-3.50015-3. Di Martino, Michael Dante. The Legend of Cherrier, Claude, and Mithat Nalbantoglu. Korra: The Art of the Animated Series - “Determination of Trace Impurities in Book Four: Balance. Dark Horse Books, Mercury and Some High Purity Acids by 2015. Spark Source Mass Spectrometry.” ———. The Legend of Korra: Turf Wars, Analytical Chemistry 39, no. 13 Part One. Milwaukie, OR: Dark Horse (November 1967): 1640–1643. Books, 2017. https://doi.org/10.1021/ac50156a041. ———. The Legend of Korra: Turf Wars, Cipriani, Nicola. The Encyclopedia of Rocks Part Three. Milwaukie, OR: Dark Horse and Minerals. New York: Barnes & Books, 2018. Noble Books, 1996. Virginia.gov. “Division of Geology and Clarkson, Thomas W., and Laszlo Magos. Mineral Resources - Minerals.” “The Toxicology of Mercury and Its Accessed 20 June 2020. Chemical Compounds.” Critical Reviews https://www.dmme.virginia.gov/DGMR/ in Toxicology 36, no. 8 (1 Jan. 2006): minerals.shtml. 609–662. Dos Santos, Joaquim, and Katie Ryu, Ki https://doi.org/10.1080/10408440600845 Hyun. “The Aftermath.” TV Broadcast. 619. Avatar: The Legend of Korra. Cuff, Thomas. “Passivation Layer on Noble Nickelodeon, 19 May 2012. Metals,” 14 Mar. 2016. E04 Committee. “ASTM E112-13, Test https://doi.org/10.13140/RG.2.1.3354.28 Methods for Determining Average Grain 02. Size.” ASTM International. Accessed 9 Di Martino, Michael Dante, and Aaron July 2020. Ehasz. “The Crossroads of Destiny.” TV https://doi.org/10.1520/E0112-13. Broadcast. Avatar: The Last Airbender. Elliott, T. A, and M. C Wilkinson. “The Nickelodeon, 1 Dec. 2006. Effect of Base-Metal Impurities on the Di Martino, Michael Dante, Bryan Surface Tension of Mercury.” Journal of Konietzko, and Gene Luen Yang. The Colloid and Interface Science 40, no. 2 (1 Aug. 1972): 297–304.

The Phoenix Papers, Vol. 4, No. 2, October 2020 20

https://doi.org/10.1016/0021- Williams, R. Heiner Schirmer, and Elias 9797(72)90020-3. S. J. Arnér. “Active Sites of Thioredoxin Fantauzzi, Donato, Sandra Krick Calderón, Reductases: Why Selenoproteins?” Jonathan E. Mueller, Mathias Grabau, Proceedings of the National Academy of Christian Papp, Hans-Peter Steinrück, Sciences of the United States of America Thomas P. Senftle, Adri C. T. van Duin, 100, no. 22 (28 Oct. 2003): 12618– and Timo Jacob. “Growth of Stable 12623. Surface Oxides on 111Pt at Near-Ambient https://doi.org/10.1073/pnas.213451010 Pressures.” Angewandte Chemie 0. International Edition 56, no. 10 (2017): Haynes, William M., ed. CRC Handbook of 2594–2598. Chemistry and Physics, 97th ed. CRC https://doi.org/10.1002/anie.201609317. Press, 2016. Fehlner, F. P. “Low Temperature Oxidation, Heck, Colin, and Katie Mattila. “The the Role of Vitreous Oxides,” 1 Jan. Calling.” TV Broadcast. Avatar: The 1986. Legend of Korra. Nickelodeon, 18 July https://www.osti.gov/biblio/5328041- 2014. low-temperature-oxidation-role-vitreous- Howatson, A. M, P. G. Lund, and joint oxides. author.) Todd J. D. (Joseph Derwent. Filoni, Dave, and Matthew Hubbard. “Engineering Tables and Data.” London: “Imprisioned.” TV Broadcast. Avatar: Chapman and Hall, 1972. The Last Airbender. Nickelodeon, 25 https://trove.nla.gov.au/version/2634630 Mar. 2005. 4. Goldstein, J. I., E. R. D. Scott, and N. L. Hursh, John B., Thomas W. Clarkson Ph.D, Chabot. “Iron Meteorites: Ellen F. Miles B.Sc, and Lowell A. Crystallization, Thermal History, Parent Goldsmith M.D. “Percutaneous Bodies, and Origin.” Geochemistry 69, Absorption of Mercury Vapor by Man.” no. 4 (1 Nov. 2009): 293–325. Archives of Environmental Health: An https://doi.org/10.1016/j.chemer.2009.01 International Journal 44, no. 2 (1Apr.): .002. 120–127. Graham, Ian, and Katie Mattila. “Old https://doi.org/10.1080/00039896.1989.9 Wounds.” TV Broadcast. Avatar: The 934385. Legend of Korra. Nickelodeon, 18 July Ian, Graham, and Tim Hendrick. “Day of the 2014. Colossus.” TV Broadcast. Avatar: The Greenwood, Norman Neill, Alan Earnshaw, Legend of Korra. Nickelodeon, 19 Dec. E. Earnshaw, and Earnshaw A. 2014. Chemistry of the Elements. Oxford: Lagowski, J.J., ed. Chemistry : Foundations Butterworth-Heinemann, 1984. and Applications. New York : Gromer, Stephan, Linda Johansson, Holger Macmillan Reference USA, 2004. Bauer, L. David Arscott, Susanne http://archive.org/details/chemistryfound Rauch, David P. Ballou, Charles H. at0000unse.

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Lindsay, Stephen J. “Very High Purity https://doi.org/10.1016/0021- Aluminum: An Historical Perspective.” 9517(88)90039-5. JOM 66, no. 2 (1 Feb. 2014): 217–222. “Mercury (Metal).” Encyclopedia.Com. https://doi.org/10.1007/s11837-013- Accessed 12 June 2020. 0843-5. https://www.encyclopedia.com/science- Linster, Carole L., and Emile Van and-technology/chemistry/compounds- Schaftingen. “Vitamin C Biosynthesis, and-elements/mercury-metal. Recycling and Degradation in Morgan, John W., and Edward Anders. Mammals.” The FEBS Journal 274, no. “Chemical Composition of Earth, Venus, 1 (2007): 1–22. and Mercury.” Proceedings of the https://doi.org/10.1111/j.1742- National Academy of Sciences of the 4658.2006.05607.x. United States of America 77, no. 12 Lioi, Anthony, and John O’Bryan. “The (December 1980): 6973–6977. King of Omashu.” TV Broadcast. Müller, W. J., and E. Löw. “Passivity of Avatar: The Last Airbender. Gold.” Transactions of the Faraday Nickelodeon, 18 Mar. 2005. Society 31, no. 0 (1 Jan. 1935): 1291– MacMullan, Lauren, and John O’Bryan. 1299. “Avatar Day.” TV Broadcast. Avatar: https://doi.org/10.1039/TF9353101291. The Last Airbender. Nickelodeon, 28 Nishimura, Shigeo. Handbook of Apr. 2006. Heterogeneous Catalytic Hydrogenation Malvadkar, Shreekant B., Sarah Forbes, and for Organic Synthesis. Hoboken, NJ: Gilbert V. McGurl. “Coal Resources, Wiley, 2001. Formation Of.” In Encyclopedia of Olsson, C.O.A., and Dieter Landolt. Energy, ed. Cutler J. Cleveland, 529– “Passive Films on Stainless Steels - 550. New York: Elsevier, 2004. Chemistry, Structure and Growth.” https://doi.org/10.1016/B0-12-176480- Electrochimica Acta 48 (1 Apr. 2003): X/00281-3. 1093–1104. Mc Auley, Mark T., Alvaro Martinez https://doi.org/10.1016/S0013- Guimera, David Hodgson, Neil 4686(02)00841-1. Mcdonald, Kathleen M. Mooney, “Online Materials Information Resource - Amy E. Morgan, and Carole J. Proctor. MatWeb.” Accessed 14 June 2020. “Modelling the Molecular Mechanisms http://www.matweb.com/index.aspx. of Aging.” Bioscience Reports 37, no. 1 Orem, W. H., and R. B. Finkelman. “9.8 - (23 Feb. 2017). Coal Formation and Geochemistry.” In https://doi.org/10.1042/BSR20160177. Treatise on Geochemistry (Second McCabe, R. W., C. Wong, and H. S. Woo. Edition), eds. Heinrich D. Holland and “The Passivating Oxidation of Karl K. Turekian, 207–232. Oxford: Platinum.” Journal of Catalysis 114, no. Elsevier, 2014. 2 (1 Dec. 1988): 354–367. https://doi.org/10.1016/B978-0-08- 095975-7.00708-7.

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Paneth, F. A. “The Discovery and Earliest Samsonov, G. V. “Mechanical Properties of Reproductions of the Widmanstätten the Elements.” In Handbook of the Figures.” Geochimica et Cosmochimica Physicochemical Properties of the Acta 18, no. 3 (1 Feb 1960): 176–182. Elements, ed. G. V. Samsonov, 387–446. https://doi.org/10.1016/0016- Boston: Springer US, 1968. 7037(60)90085-5. https://doi.org/10.1007/978-1-4684- Park, Jung-Duck, and Wei Zheng. “Human 6066-7_7. Exposure and Health Effects of Sandalova, T., L. Zhong, Y. Lindqvist, A. Inorganic and Elemental Mercury.” Holmgren, and G. Schneider. “Three- Journal of Preventive Medicine and Dimensional Structure of a Mammalian Public Health 45, no. 6 (November Thioredoxin Reductase: Implications for 2012): 344–2352. Mechanism and Evolution of a https://doi.org/10.3961/jpmph.2012.45.6 Selenocysteine-Dependent Enzyme.” .344. Proceedings of the National Academy of Pleshakov, Edward. “Micrograph of a Sciences 98, no. 17 (14 Aug. 2001): Polycrystalline Metal; Grain Boundaries 9533–9538. Evidenced by Acid Etching.” Wikipedia, https://doi.org/10.1073/pnas.171178698. 14 June 2020. Shirley, J. H., and Rhodes W. Fairbridge, https://en.wikipedia.org/w/index.php?titl eds. Encyclopedia of Planetary Sciences. e=Grain_boundary&oldid=962465594. Heidelberg: Springer Netherlands, 1997. Res, J. Dent, John P. Nielsen, J. J. Tuccillo. https://www.springer.com/gp/book/9781 “Grain Size in Cast Gold Alloys.” 402045202. Journal of Dental Research 45, no. 3 Sigel, Astrid, and Helmut Sigel. Metal Ions (May 1966): 964-969. in Biological Systems: Volume 34: https://doi.org/10.1177/00220345660450 Mercury and Its Effects on Environment 037701 and Biology. Boca Raton, FL: CRC Richardson, Stephen H., and Steven B. Press, 1997. Shirey. “Continental Mantle Signature of Spaulding, Ethan, and Aaron Ehasz. “Bitter Bushveld Magmas and Coeval Work.” TV Broadcast. Avatar: The Last Diamonds.” Nature 453, no. 7197 (June Airbender. Nickelodeon, 2 June 2006. 2008): 910–913. Spaulding, Ethan, and John O’Bryan. “The https://doi.org/10.1038/nature07073. Earth King.” TV Broadcast. Avatar: The Rudnick, R. L., and S. Gao. “3.01 - Last Airbender. Nickelodeon, 17 Nov. Composition of the Continental Crust.” 2006. In Treatise on Geochemistry, eds. “Steel: Composition, Properties, Types, Heinrich D. Holland and Karl K. Grades, & Facts.” Encyclopedia Turekian, 1–64. Oxford: Pergamon, Britannica. Accessed 12 June 2020. 2003. https://doi.org/10.1016/B0-08- https://www.britannica.com/technology/ 043751-6/03016-4. steel.

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“Surface Passivation - an Overview.” Train.” reddit, 2014. ScienceDirect Topics. Accessed 14 June https://www.reddit.com/r/TheLastAirben 2020. der/comments/2juf1d/b4e1_i_attempted_ https://www.sciencedirect.com/topics/en to_make_a_semiaccurate_map_that/. gineering/surface-passivation. Volpe, Giancarlo, Michael Dante Di Tansel, Berrin, John Sager, Tony Rector, Jay Martino, and Bryan Konietzko. “The Garland, Richard F. Strayer, Lanfang Guru.” TV Broadcast. Avatar: The Last Levine, Michael Roberts, Mary Airbender. Nickelodeon, 1 Dec. 2006. Hummerick, and Jan Bauer. Walsh, Kevin. “Widmanstätten Pattern.” “Significance of Hydrated Radius and Wikipedia, 7 May 2020. Hydration Shells on Ionic Permeability https://en.wikipedia.org/w/index.php?titl during Nanofiltration in Dead End and e=Widmanst%C3%A4tten_pattern&oldi Cross Flow Modes.” Separation and d=955372056. Purification Technology 51, no. 1 (1 Wasson, J. T. Meteorites: Classification and Aug 2006): 40–47. Properties. Minerals, Rocks and https://doi.org/10.1016/j.seppur.2005.12. Mountains. Berlin Heidelberg: Springer- 020. Verlag, 1974. “Tensile Strength: Definition, Unit, & https://doi.org/10.1007/978-3-642- Facts.” Encyclopedia Britannica. 65863-1. Accessed June 13, 2020. Wright, W. W. “Materials Science and https://www.britannica.com/science/tens Engineering. An Introduction.” 2d ed. ile-strength. Polymer International 30, no. 2 (1993): “The PGM Database.” Accessed 14 June 282–283. 2020. https://doi.org/10.1002/pi.4990300228. http://www.pgmdatabase.com/jmpgm/in Yee, F. C., and Michael Dante Di Martino. dex.jsp?record=1064. Avatar, The Last Airbender: The Rise of The PyMOL Molecular Graphics System Kyoshi. New York: Harry N. Abrams, (version 1.2r3pre). Schrödinger, LLC., 2019. n.d. Zwyer, Melchior, and Tim Hendrick. “The “Toxicological Profile for Mercury.” Search Coronation.” TV Broadcast. Avatar: The Results Web Result with Site Links Legend of Korra. Nickelodeon, 17 Oct. Agency for Toxic Substances and 2014. Disease Registry, March 1999, 354–358. Zwyer, Melchior, Tim Hendrick, and Joshua u/YellowPudding. “R/TheLastAirbender - Hamilton. “Venom of the Red Lotus.” [B4E1] I Attempted to Make a Semi- TV Broadcast. Avatar: The Legend of Accurate Map That Kuvira Had on the Korra. Nickelodeon, 22 Aug. 2014.

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Figure 2: A sample of hematite, a common iron oxide mineral. Oxides of iron and other metals are extremely common constituents of minerals in all rock types.

Figure 1: Shown is the catacomb crystal armor (top) utilized by Avatar Aang in the catacombs below Ba Sing Se and the covering of jennamite (bottom) that immobilized Sokka and Katara upon meeting King Bumi.

Figure 3: When successfully metalbending for the first time, Toph was able to visualize the chemical impurities and/or carbon particles within the metal of the cage. Manipulation of these allowed her to bend the bulk metal.

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Figure 5: Diagram of the passivation process. In this case, the aluminum metal is protected from further oxidation by the Figure 4: Micrograph of a quenched barrier of aluminum oxide which forms from titanium wrought alloy after acid etching to contact with oxygen in the air. Not every accentuate grain boundaries. Clearly visible metal’s oxide layer is passivating. are the cross-sections of individual grains, each with a uniquely oriented crystal structure relative to one another.

Figure 6: Etched cross-section of a Figure 7: Section of the crystal metal meteorite found in Namibia structure for rat TrxR (PDB 1H6V) displaying a fine Widmanstätten showing one of the conserved C- pattern. In this image the average terminal Gly-Cys-SeCys-Gly phase width is 0.3 mm. sequences which are responsible for the binding of mercury. Figure generated with PyMOL.

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Figure 9: Map of the Earth Kingdom overlaid with the relative locations of Zaofu (northeast point) and the Chin Figure 8: The mercury that Korra removed peninsula (southwest point). The from her body was reduced back to its proximity of the two is apparent. elemental metallic form in the process. Original image used with permission of The volume suggests that around a Reddit u/YellowPudding. kilogram of metal was removed. This amount should be a fraction of the total that was left behind in 171 AG.

Table 1: Tensile and Yield Strengths of Relevant Metals.

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