Letter from a Crank(y) Physicist
Reclassification of Plutonium as a Dwarf Element
Department of Physics
Loyola University Chicago
October 4, 2006
The recent reclassification of Pluto as a dwarf planet by the International Astronomical Union1 has raised the issue that other namesakes of the god of the underworld may have been similarly misclassified. Plutonism, the geologic theory that volcanic activity was the source of rocks on the surface of the Earth, has proved to be only partially true. (Its competitor, neptunism theory, that rocks had originated from a great flood and were basically sedimentary in origin, has suffered a similar fate.) Today, rocks and minerals are considered to be of both igneous and sedimentary, as well as metamorphic origin2 (hereby dubbed proteanism). At best then, plutonism is a dwarf theory of geology.
II. Characteristics of plutonium
It is thus important to re-examine the element plutonium, and ascertain whether it merits the status thus far ascribed to it. "Plutonium is a radioactive, metallic chemical element....It can be made from natural uranium and is fissile....All isotopes and compounds of plutonium are toxic..."3. Let us consider these characteristics, and compare them with those of more well-established elements.
1. Plutonium is radioactive. Its most stable isotope has a half-life of only 8.0 x 107 years, while the most stable isotope of uranium (a mere two atomic numbers below it), 238U has a half-life of 4.5 x 109 years: over fifty times longer. The plutonium isotope which is important for nuclear power production, 239Pu, lives for a mere 2.4 x 104 years while uranium's important nuclear power isotope, 235U, has a half-life of 7 x 108 years, nearly thirty thousand times longer. Thus, plutonium in both its most stable and its most important forms is hardly around long enough to be of any utility.
2. Plutonium is metallic. This is a formally correct statement; viz., the ground state of neutral plutonium has an open shell that is less than half-filled with electrons. However, metallic behavior generally comprises additional characteristics: malleability, ductility, and high thermal and electrical conductivity. Many much less exotic elements such as copper, silver, and iron easily meet some or all of these criteria. An extensive search of the literature and the houses of neighbors has failed to unearth any plutonium wiring whatsoever. Even if some were to be fabricated, the minuscule half-life of the isotope would lead to innumerable short circuits and perhaps even electrical fires.
3. Plutonium is made from natural uranium and is fissile. In this, it is like several other transuranic elements; namely, dependent on the presence of lower atomic number elements for its very existence. (Not surprisingly, its nearest partner is the similarly ephemeral neptunium.) Once produced, plutonium is extremely fissile, either naturally decaying as noted above, or simply coming apart with the slightest nudge from even such small particles as neutrons. In weapons applications, plutonium needs to be alloyed with another metal (i.e., one that behaves like a real metal) for stability. Thus, plutonium owes its very existence to a parasitic relationship with other elements.
4. All isotopes and compounds of plutonium are toxic. While this characteristic might provide plutonium with enough cachet to rank as a real element, closer examination reveals that even in toxicity it falls far short of expectations. "As of 2006, there has yet to be a single human death officially attributed to exposure to plutonium itself. Naturally-occurring radium is about 200 times more radiotoxic than plutonium.....Botulin toxin has a lethal dose...far less than...plutonium....[C]arbon-14 and potassium-40 in nearly all food...can cause cancer on casual contact, which...plutonium cannot....[P]lutonium is less poisonous...than ...caffeine, acetaminophen, some vitamins, pseudoephedrine, and any number of plants and fungi. It is perhaps somewhat more poisonous than pure ethanol, but less so than tobacco and many illegal drugs."3 This assessment is hardly a testimonial to plutonium's eligibility for the toxicity elite.
An objective assessment of plutonium's characteristics therefore leads inexorably to the conclusion that it fails to meet virtually all of the requirements for full inclusion in the periodic table of the chemical elements, or the table of nuclides, or the list of poisons. It is therefore proposed that plutonium be removed from those compendia and reclassified as a "dwarf element." While this may lead to the demotion of a number of its transuranic neighbors, that is the price that must be paid for scientific integrity.
Acknowledgments: I am grateful to Professor Steven Lubet for pointing out that plutocracy (although deriving from ploutus: wealth, rather than the god) is a stunted form of government, and to Dottore Alberto Rapp for suggesting that the Disney dog is, without his makeup, a chihuahua.