Pile

Pile (pronounced pahyl)

(1) An assemblage of things laid or lying one upon the other.

(2) Slang for a large number, quantity, or amount of anything.

(3) A heap of wood on which a dead body, a living person, or a sacrifice is burned; pyre the more common form.

(4) Slang term for a lofty or large building or group of buildings.

(5) In metallurgy, a bundle of pieces of iron ready to be welded and drawn out into bars; fagot.

(6) In electricity, slang for a voltaic pile.

(7) To gather, accumulate, or rise in a pile or piles (often followed by up).

(8) In construction, a long column of timber, concrete, or steel that is driven into the ground to provide a foundation for a vertical load (a bearing pile) or a group of such columns to resist a horizontal load from earth or water pressure (a sheet pile)

(9) In heraldry, an ordinary in the form of a wedge or triangle coming from one edge of the escutcheon, from the chief unless otherwise specified.

(10) In archery, the sharp head or striking end of an arrow, usually of metal and of the form of a wedge or conical nub.

(11) A fabric with a surface of upright yarns, cut or looped, as corduroy, Turkish toweling, velvet, and velveteen.

(12) In nuclear physics, a structure of uranium and a moderator used for producing atomic energy; nuclear reactor.

Pre 1000: Middle English pile from Old English pīl (shaft) derived from the Latin pīlum (javelin) and pīla (pillar or mole of stone).  Variations emerged in Late Middle English, pyles from 1375–1425 was a plural of the Latin pilae (literally, balls) and from 1300–50 piles (hair, plumage) from the Latin pilus (hair), the -i- short in Latin but long in Anglicized school pronunciation.  The Middle English pyl (reverse of a coin) was a special use of the Medieval Latin pīla.  Word actually passed to English from the Old French pyle. 

The meaning "mass or heap" was universal by the early fifteenth century, originally "pillar, pier of a bridge," from Middle French pile and directly from Latin pila "stone barrier, pillar, pier"; the development in Latin from "pier, harbor wall of stones," to "something heaped up" and the meaning "large building", common by the fourteenth century is probably the same word.  The "heavy pointed beam" is from the Old English pil (stake), as "arrow" is from the Latin pilum (heavy javelin of the Roman foot soldier, literally pestle), source of the Old Norse pila, the Old High German pfil, and the German pfeil (arrow).  Of all these, origin is uncertain.  The meanings as applied to fabrics and downy plumage are from the Anglo-French pyle or the Middle Dutch pijl, both from Latin pilus (a hair), source of the Italian pelo and Old French pel.  Phonological evidence rules out transmission of the English word via the Old French cognate peil and poil; meaning "nap upon cloth" emerged in the 1560s.  The most familiar modern meeting (to heap up) is from the mid fourteenth century while the figurative verbal expression “pile on” (attack vigorously, attack en masse) is an Americanism from 1894.

Chicago Pile-1

The atomic pile was the original name for a nuclear reactor, a device used to initiate and control a self-sustained nuclear chain reaction.  Chicago Pile-1 (CP-1) was the world's first nuclear reactor and on 2 December 1942, the first human-made self-sustaining nuclear chain reaction was initiated.

Chicago Pile-1, 1942                          

CP-1 was built with 45,000 graphite blocks weighing 360 tons used as neutron moderators, fueled by 5 tons of uranium metal and 45 tons of uranium oxide which, despite the bulk, produced only a tiny amount of power, about one-half watt. The original design intended the shape to be spherical but, during construction, it was calculated the critical mass required for a chain-reaction could be achieved with a smaller pile.  Disassembled in 1943, CP-1 was reconfigured to become Chicago Pile-2 (CP-2) and it operated in that form until 1954 when it was dismantled and buried.

A pile of granite blocks (left) and Lindsay Lohan with several stacks of pregnancy books (right), out-take from Labor Pains (2009).

The term "atomic pile" is a historic artefact from the early years of the science but essentially they were the first nuclear reactors, the term derived from what the physicists at the time visualized as a "pile" of the graphite blocks used to moderate the nuclear reaction.  Why the word "pile" was chosen as a descriptor doesn't seem to have been recorded but it must at the time have seen an obvious choice although, the convention in English would have been to use "stack" because although "pile" and "stack" both refer to agglomerations of objects (although can figuratively also be used of the non-physical), the two have slightly different connotations.  A pile tends to be an unordered heap of items, placed without much care to produce a random or shape ("pile of clothes on the floor", "pile of leaves in the yard" etc).  By contrast, a stack is a more orderly arrangement of items placed atop each other ("stack of books on a table", "stack of plates in a cupboard" etc), suggesting something and structured (although the stuff in the stack could in some ways be quite haphazard (ie not in alphabetical order etc).   So, a pile tends to appear to be disordered or unstructured, while a stack suggest some sense of deliberate organization.  None of that suggest the early, pioneering theorists and researchers were wrong in their choice of word.  The first nuclear reactors were called a pile to reflect the basic, rather unrefined way the components were "piled together"; these really were scientific experiments and not without risk, a number of scientists and engineers who worked in close proximity to Chicago Pile-1 dying prematurely from internal cancers, including Italian-American physicist Enrico Fermi (1901–1954), the device's designer & builder.