.pl

1. Perl script filename extension.
2. Prolog filename extension.

.pl

(Domain code for) Poland. There is a homepage written in a foreign language and also available in English. If you're interested, the English edition of a Polish electronic newsletter (DONOSY) is archived.

UB hosts a Polish Academic Information Center.

PL

PhotoLithography. Photographically exposing an image on the surface of a wafer in order to create a mask for some fabrication process (i.e., to define ``windows'' -- regions exposed to deposition, diffusion, implantation, and other fabrication processes).

Image at right is from Patricia Schank and Lawrence Rowe, U.C. Berkeley.

PL

PhotoLuminescence. Immediate emission of light induced by photoexcitation. You know it's not reflection because the luminescence has a different spectrum (lower-energy, absent some Stokes effect) than the exciting light. If there's a significant delay in some of the emission, it's called fluorescence.

Photoluminescence is a physical process, of course, and a signal that can be usefully measured. The measurement of photoluminescence, which is usually done as a spectroscopy (i.e., the signal is measured as a function of light wavelength or frequency) is usually also just called ``photoluminescence'' or PL.

PL

Physical Layer (of ATM).

PL

Piecewise-Linear.

Pl.

PLato.

Pl

PLease. Mail and email abbreviation. Also abbreviated Pls. Don't beg.

pl.

PLural. As a grammatical term, it generally applies to inflected forms distinguished from the singular (sg. or sing.) or distinguished from the singular and dual. In Indo-European (IE) languages nowadays, duals are rare, but Icelandic retains a distinction between a dual first-person pronoun (we two) and a plural (we all).

PL

Private Line.

P & L

Profit-and-Loss (statement; analysis).

PL

Programming Language.

P & L

Projects and Logistics.

PLA

People's Liberation Army. The Army of the PRC and other ``people's'' tyrannies. That's the name, anyway.

PLA

Programmable Logic Array. A proprietary name for a Programmable Logic Device.

PLA

Public Library Association. A division of the ALA.

PLA

Pulsed Laser Ablation.

placard

A word with more meanings in French and English than I care to list. The word was also borrowed from French into Dutch, and thence into German.

Spanish also borrowed it; spelled placarte, it has the relatively restricted sense of an official notice posted on walls or at streetcorners. I suppose the word was borrowed when the final d in the French word was still pronounced. The spelling placard is used in Argentine Spanish for a word pronounced placar. (This would be the natural pronunciation anyway if the word had been borrowed from English, but the pronunciation apparently follows the French.) This placard is a closet -- a wardrobe that's built into a wall. In Spain one would say un armario empotrado. The word armario, corresponding to the place or piece of furniture in which one keeps clothing (rather that wardrobe that one keeps in it), is etymologically equivalent to the English word armory: a place where one keeps one's armor. (One of the original senses of wardrobe was the same -- a place to keep one's armor. Hardwear, so to speak.)

plague, purple

1. The NCAA requirement, in effect since 1983, that the home football team wear colored jerseys, as manifested 1983-1995 at LSU.


2. Purple Loosestrife, or Lythrum salicaria a hardy and pretty weed from Europe, useful for drying up wetlands. Available from landscape supply stores, according to this source, which provides a map indicating that Louisiana is one of only nine states not suffering this plague.


3. A children's TV show about a purple dinosaur. See the PDOS entry.


4. An interconnect failure problem at interfaces of Gold (Au) and Aluminum (Al). [According to this transcript of an interview with J. Leland Atwood, the problem was first discovered during the deployment of Minuteman II ballistic missiles in the 1970's.] The gold-aluminum system makes a number of intermetallics, and the interconnect failure problem took its name from AuAl₂, which happens to be a good conductor. In fact, breakdown can occur in a couple of ways:
   1. Above 624 °C, a transformation yields Au₂Al. This is a poor conductor, but its color is tan and its presence is easily missed when the purple AuAl₂ is present. If the presence of this high-resistance intermetallic causes failure, then electrical failure can precede mechanical failure.
   2. At temperatures as low as 400-450 °C, intermetallics begin to form at the interface between aluminum and gold (the eutectic is at 370°); this progresses by interdiffusion, and a sequence of layers with different compositions forms, in order from Au-rich to Al-rich, growing at different rates. As a slower-growing layer is overtaken and consumed by a faster-growing dense layer, cavities form. This process is called Kirkendahl voiding, and leads to brittle and broken interconnects that fail electrically because they fail mechanically.
   This is an example of a problem that is so bad, it's not a problem at all: no one ever bonds gold wire to an aluminum bonding pad. At any rate no one does so and continues to be employed at that general sort of work. Infectious diseases are like that too: strains of virus that are instantly fatal to all their hosts don't have the same opportunity to propagate as less virulent strains.
   
   Intermetallic compounds grow from the interface of solid reactants in a process that is diffusion-limited, so the rate is proportional to the square root of time. Since the ionic diffusion process is activated, the thickness growth is as well.
   
   The other metals in gold's period -- copper (Cu) and silver (Ag) -- also form unwelcome intermetallics with aluminum, only not as fast as gold does. A small percentage of copper (0.5%) is included in aluminum interconnects to alleviate the problem of electromigration failure (passivation layers -- PSG and the like -- do the rest).
   
   Problems caused by Au₅Al₂ are called white plague.


5. A phrase William Blake used in his The French Revolution, to describe I'm not sure what, but it may have to do with the fact that the color purple was in medieval times reserved to royalty, so that it even took on the character of synecdoche. This probably has nothing to do with the movie, ``The Color Purple.''


6. A bug in the DynamIP, a free multi-functional internet utility, in which a window turns purple (indicating that connectivity has been lost). Sounds like a cool multidysfunctional feature to me.

plague, red

1. A rock band that broke up in 1998. It had a distinctive Canadian-content sound, hey. Manitoban sort-of-punk. Words fail me.


2. Erysipelas. In Shakespeare's ``The Tempest,'' (Act I, Sc. 2) Caliban says

   You taught me language, and my profit on't
   Is, I know how to curse. The red plague rid you
   For learning me your language.
   



3. Early 20th-c. euphemism, or maybe dysphemism, for prostitution.


4. Vibriosis ``... a systemic bacterial infection of primarily marine and estuarine fishes, caused by bacteria of the genus Vibrio (Ross et al. 1968; Ghittino et al. 1972) [cites listed as endnotes at entry]; it is a major cause of mortality in mariculture operations. It sometimes also occurs in freshwater species. ''
   
   ``Vibriosis has been known for centuries; outbreaks were recorded as early as the 1500's along the Italian coast. Terms such as "red pest," "red boil," "red plague," or "saltwater furunculosis" have been used to describe vibrio infections, but "vibriosis" is now the specific and standard name of the disease.''

plague, white

1. Gold-Aluminum intermetallic compound Au₅Al₂ and the problems it causes for gold-aluminum interconnects. Cf. purple plague supra.

2. Any epidemic disease that makes one pale, principally tuberculosis (TB) in the nineteenth and early twentieth centuries.

3. The White Plague (New York: Putnam, 1982) is a sci-fi story by Frank Herbert (better known as the author of the Dune books), in which an epidemic plague is created by a molecular biologist maddened by the IRA bombing murder of his wife and kids. A rather misogynistic plague, too: it only kills females. In J. D. Beresford's, A World of Women, 1913, the plague gets males only, but there it's the story itself that's misogynistic.

4. ``The White Plague'' is a translation of Bílá nemoc, a play about fascism by Karel Capek (see R. U. R.), adapted into a two-hour movie, directed by Hugo Haas (who cast himself in the starring rôle of altruistic slum doctor) in 1937 (!). Haas and cinematographer Otto Heller fled Czechoslovakia after the Nazi occupation (sanctioned by Neville Chamberlain at the infamous Munich capitulation). Hugo Haas went to Hollywood, Heller to Britain. Never saw it, but it sounds as pure-hearted and pitifully naïve as you like.

5. A disease of unknown cause that afflicts coral in the summer.

6. Heavy hail.
7. Inappropriate snow.

Plainville, USA

Plainville is the pseudonym used for a small Missouri farming community that was the subject of an anthropological study by Carl Withers, who lived there from June 1939 to August 1940 (and made a further visit during July and August 1941). He published the study in 1945 under the title Plainville, USA, using the pseudonym James West for himself.

Art Gallagher, Jr., went to the town in 1954 and found that the local folk remembered ``West'' and knew about the book, which they resented; they believed it showed them in a poor light and even purposely exposed them to ridicule. Nevertheless, Gallagher spent his year or so there and managed to win enough cooperation for a restudy, which he published as Plainville Fifteen Years Later in 1961. That year also, the original study was reissued with the real author's name. (This is handy to understand if you're searching a library catalogue.)

Another, better-known anthropological study of a ``modern'' (i.e. industrialized-world) community was that of Middletown, USA (Muncie, Indiana), which suffered through at least two restudies. ``Jonesville,'' Illinois was studied by a separate researcher as ``Elmtown.'' There have been dozens of such studies; I think that the best-known, if it isn't the Lynds' original study of Middletown, is that of ``Yankee City,'' Massachusetts. Of those studies I've read, the most interesting was Withers's of Plainville, perhaps because the relative backwardness allowed a look deeper into the past. This will become apparent as I start adding tidbits from the Plainville studies to other entries.

planet

I imagine you know what a planet is, so for now this entry will be about what planets were, or more precisely about the etymology of the word planet.

Until the heliocentric-universe idea started to gain traction in the seventeenth century, ``planets'' were those discrete heavenly bodies distinguished from the ``fixed stars.'' The fixed stars were the large number of bright points that maintained fixed relative positions in the sky (even as they ``turned,'' in geocentric terms). In modern terms, of course, each individual fixed star was either a star nearby within the Milky Way, or a group of stars too close to be distinguished by the naked eye. Strictly speaking, they were not exactly fixed, but their relative positions changed imperceptibly. The angular motion of celestial objects as seen from earth is called proper motion, and this was not detected until the eighteenth century.

The fixed stars were conceived to be fixed upon a distant spherical surface (the ``firmament'') that rotated around the earth once per sidereal day. Atlas wasn't imagined to hold up the Earth -- that's ridiculous! Earth was at the center of the universe and didn't need to be held up. Atlas held up the firmament.

Seven ``planets'' were known in antiquity: the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. These were the objects that, in striking contrast to the fixed stars, wandered across the sky below the firmament. The ancient terms express this idea. In Classical Latin the common term for any of these seven objects was stella errante, `wandering star.' The second Latin word is the present participle of errare, which meant to wander. (You recognize in this the origin both of the English term ``knight errant'' and words like err and error.)

The plural -- wandering stars -- was stellae errantes. The corresponding Greek plural was astéres planêtai; from this, Latin borrowed planetae, a less common word for `planets.' Since the individual planets all have particular names, a word for planet is likely to occur more frequently in the plural. That may not entirely explain the fact that the singular form planeta is not attested at all in extant Classical Latin texts, but anyway it became common in late Latin.

Planeta is the singular form of the word in modern Spanish and Portuguese (as well as Czech and, properly transliterated, Russian). In Italian, it's pianeta. The pl to pi is a regular shift, evident in piano, piattaforma, piazza, piegare (`to fold,' cogn. with Sp. plegar), piombare (`to plumb'; I hope you guessed that), appiombo (`perpendicularly'), più, and piuma. On the other hand, Italian has plenty of words with pl, many Latinate, and I'm not sure what the rule for the sound shift is, if there is one. Among the words with pl are planetario [for `planetary, planetarium, and orrery'], planetoide, planetologia, and planetologo [`planetologist'], which were, I presume, all borrowed (after the shift took place). As you realized when you learned the word chiaroscuro, the same kind of regular shift turns cl into chi.

All the languages mentioned in this entry make the word for planet female if they can (English gets a bye here) with two exceptions: Italian makes pianeta grammatically male, hence with plural pianeti. German makes Planet masculine also (plural Planeten). This reminds me of futile thoughts like the gender inversion (kinky!) of Sun and Moon (male and female in Romance languages, vice versa in German and Old English).

You know, when I started writing this entry I only planned to point out that the English word planet comes from the Ancient Greek planêtês, meaning `wanderer.' Then I was just going to say, ``You knew that, of course, but here's something interesting: The Sumerians and the Akkadians (the pre-Babylonian inhabitants of the Euphrates valley) had a cool humanizing (can I call it `anthropomorphizing'?) terminology for the planets as well. They called the stars collectively by a term that meant `heavenly flock,' and they called the seven planets something equivalent to `old-sheep stars,' reflecting the idea that old sheep may stray. (The singular old sheep was the sun.)'' Then the editor pestered me about the capitalization, and suddenly the entry ballooned astronomically. Never start something like this on a weekend when you've got time to spare.

The list of planets above was given in order of increasing distance from Earth, according to the consensus of opinion in classical antiquity. There were other canonical orders, however. (Mostly in the Near East, I think.) The days of the week are named in order after the Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn. This arose from an Egyptian practice of naming parts of the day after the planets. Because the seven parts didn't go evenly into a single day, each successive day began (and was called after) a different planet. Later I'll track down the details and move this discussion to a week entry. For now you should know that apart from the astronomically natural time units of day, month (moon), and year, other divisions of the calendar comparable to the seven-day week were used (three- and ten-day periods, that I can recall off-hand). The seven-day week apparently spread around the Mediterranean independently of Jews and Christians.

The Modern Greek word for planet is planêtês, the same as the ancient word for wanderer (except that first letter eta, transliterated ê in English texts that bother to distinguish it from epsilon, is normally written with a circumflex accent for Ancient Greek, and with the common accent, similar to an acute accent, in Modern Greek; you have no idea what problems are associated with this in Unicode).

I've been told that the Greek word in its modern sense is regarded as being reborrowed from modern French. I hope this is true, because it would be very apt for the planetarch entry. That sounds crazy, given what I wrote above about the origin of the Latin word planetae in Greek, but it might be true in the following way: although the noun planêtai might occur in the ordinary sense of `wanderers' in Ancient Greek texts, it might not occur in isolation as a noun meaning `planets.' Instead, it might only occur as the adjective `wandering' in phrases like astéres planêtai. I did a TLG search on planêtai, and my main conclusion is that the word occurs a lot. They really shouldn't let intellectual children like me play with such sophisticated tools. I checked the first couple of dozen hits, and it does seem to me (proceed with caution) that in astronomical contexts it either modifies astéres or some other astronomical term.

Just for completeness (yeah, now I'm going for completeness; brevity is out of reach), I should mention that another Greek form was plánês, occuring in the plural expression astéres plánêtes, which gave rise to the Latin planetes. Both planet and planeta are used in English for a chasuble. That's basically a round poncho or a large one. The word was medieval Latin (7th c.) for a traveler's garment (and so presumably is from the same root as the more common planet) but now is terminology for an ecclesiastical garment. In Portuguese the corresponding use of planeta is apparently not obsolete. I just had to mention that.

You know, in the werewolf scene in Satyricon, the guy who doesn't turn into a werewolf counts stars. There's more. People find this puzzling. (I'm trying to imitate the effective ``style'' of Satyricon arising from the fragmentary form in which it has reached us. Completeness is impossible.)

I hear that in 2006 we lost a planet! After astronomers worked so hard to find them! I'll get right on it.

PLANET

Probing Lensing Anomalies NETwork. A network of five (as of 2008) one-meter optical telescopes ``distributed in longitude around the southern hemisphere in order to perform quasi-continuous round-the-clock precision monitoring of Galactic bulge microlensing events.'' This microlensing collaboration has been operating since 1995. Since 2005 it has coordinated closely with RoboNet. See MicroFUN or MOA for more about microlensing and why it's interesting.

planetarch

Translation into English of planêtarchis, coined at the end of the Cold War and still appearing in Greek newspapers as recently as 2004, meaning `ruler of the planet.' It's almost an ambivalent expression; it recognizes power but is disdainfully anti-American. In the same spirit as the French hyperpuissance, usually translated `hyperpower.' My impression from the French resources in Lexis-Nexis is that it was used as a nonce word in general context until 1998 (as for example in l'hyperpuissance des médias, `hyperpower of the media'). It seems to have taken until 1998 for the term to stick to the US (musta' been the Clinton charm), but then the popularity of the phrase took off. (Useful phrase to scribble into your traveler's phrase book: L'hyperpuissance américaine ... `the American hyperpower.' While you're at it, add préservatif ... `condom.' Believe me because I write from experience: when you need this word and it's not in your pocket, uh, dictionary, extreme awkwardness happens.)

When Natan Sharansky met President George W. Bush at the White House, he told Bush ``Now you are the chief dissident of the world.'' Cf. LFW.

PLANOX

PLANar OXide.

PLAR

Private Line Automatic Ringdown (ARD).

plasma

A gas of ions and electrons, under conditions of temperature, pressure and density such that collective, long-range behavior is exhibited. Most of the matter that we can find in the universe is in the form of plasma in stars.

Also, a gas of electrons or holes or both, in a condensed system. This does not necessarily refer to an unusual state of these particles, but suggests that the speaker or writer is interested in properties of the distribution far from equilibrium.

Also (blood plasma) the liquid portion that is left when blood cells are removed from blood.

plasma reactor

An electron tube with a gas. In operation, current between anode and cathode ionizes the gas. The resulting plasma of hot ions and electrons is used in a variety of semiconductor fabrication processes. (Vide: sputtering, plasma-enhanced-whatever, RIE, dry etching.)

plastic

Plastic, in its modern usage as an uncountable (`mass') noun, refers to synthetic polymeric materials (mostly organic, but also including inorganic polymers like silicone).

Plastics Technology Center has a lot of materials, including a polymer name acronym expander and an extensive tutorial.

Polymers DotCom talks big, and they do seem to offer some service. Go direct to their content page for links to tutorial stuff.

plasticizer

A lubricant at the microscopic level for long-chain molecules, making bulk pieces, sheets or filaments of the stuff flexible or ductile. DBP (used in commercial plastics) and water (used in living tissue) are examples.

plastic surgery

Author Olivia Goldsmith's debut novel The First Wives Club was a runaway best-seller when it came out in 1992. It's about three women who band together to seek revenge after their successful husbands discard them for younger women. It was made into a hit movie in 1996, starring Goldie Hawn, Diane Keaton, and Bette Midler. The Goldie Hawn character, a celebrity of some sort (I forget exactly which) is deep into plastic surgery (okay, she's no Jacko, but fiction has to be believable).

On January 7, 2004, as she went under general anesthesia for plastic surgery (specifically, to remove loose skin from her chin), Olivia Goldsmith suffered a heart attack and went into a coma. She never regained consciousness and died on January 15.

The Writers Directory listed her as born in 1954, but she must have been born very, very early in that year, since the announcement of her death gave her age as 54.

``Olivia Goldsmith'' was her pen name. She was born Randy Goldfield and changed her legal name to Justine Rendal.

plato

Spanish, `dish.' Cognate of English plate. A flying saucer is a plato volador.

Plato

Some very old (``ancient,'' as the French would say) Greek guy who idealized his seditious teacher.

Hey, he's got a page! Or two. And now a whole site! Just like the ancient Rolling Stones! He's hip!

Among his works is a book we now call Plato's Republic. ``Plato's Republic'' was a popular name for, uh, bathhouses back before AIDS, because pederasty was legal and considered normal in Athens and many other ancient Greek city states. Those bathhouses are becoming popular again, along with unprotected sex, now that there's a cure for AIDS. What!? There isn't a cure for AIDS!? This could be a problem....

``Plato's Republic'' is the title of a comic strip series in the adventures of Modesty Blaise (more at dead man's handle).

Plato's original name was Aristocles. Platon was his nickname. The plat- stem means `wide' or `broad,' and is probably related to the English word flat through a common Indo-European root. There are a few different stories about how Plato got his nickname and what it meant. One is that his wrestling coach gave it to him for having broad shoulders (I think I remember this from Diogenes Laërtes; have to check), another is that he had a broad forehead, another is that what was behind his forehead was figuratively broad. English doesn't preserve the final en in this name (more on that at Platón).

P.L.A.T.O.

A nonprofit organization that offers to help you get various kinds of funding, especially ``private, credit-based'' P.L.A.T.O. loans. They have a website that does not expand ``P.L.A.T.O.,'' and a toll-free number. In a spasm of investigative fervor, an SBF reporter called that number, outlasted the automated call-answering service and was placed on hold twice to be told by a loan information person and her supervisor that the letters in ``P.L.A.T.O.'' don't stand for anything. The information person did not regard this, or the use of periods in the name, as bizarre. P.L.A.T.O. is a registered trademark of EduCap, Inc.

Cf. ARISTOTLE 2000.

PLATO

1. PLanetary Analysis TOols (NASA is a repeat offender; cf. ARISTOTELES.
2. Programmed { Logic | Learning } for Automated[ic] Teaching { Operations | Options }

Plato Epictetus Marcus Aurelius

The author of a handsomely bound work entitled Excerpts, published by The Harvard Classics.

platón

Spanish, `very large dish.' From plato and regular augmentative ending -on.

Platón

Spanish, `Plato.' Preserves the final en that English drops. Apollo is in the same declension. So is Gellon, relative of Archimedes and the last king of independent Syracuse before it was conquered by the Romans, but there English keeps the en. Of course. Pharaoh is faraón in Spanish.

I saw a Soviet stamp commemorating some joint Soyuz-Apollo mission or missions, and I noticed that they also preserve the final en.

Platonic Solids

No, no, not that kind of Platonic! Platonic solids are the five solids in which all faces, edges and angles are equal. They are the tetrahedron, cube, and the regular octohedron, dodecahedron and icosahedron (4, 6, 8, 12, and 20 faces, respectively).

plato volador

Spanish, `flying saucer.'

plausible

Consistent with prejudice.

Plaut.

T. Maccius Plautus, of course. Died 184 BCE, but not before he'd written and even had performed some comedies. This was apparently before the invention of the punch line.

PLB

Payload Loop-Back.

PLBC

Proclaim Liberty Bible Church. Sounds rather Baptist. In Houston, Texas. They don't have a website, but I know they've got a minivan with that initialism on it. Sore it on US-22 in New Jersey. Takin' it to the heathens, uh-guess.

We's got a rush awn, t'see if'n we-c'n reach 25000 entries bah Nyoo Yeah, so we-uh easin' the standids some foah entry.

PLC

Palestinian Legislative Council.

PLC

Planar Lightwave Circuit[s].

PLC

Platoon Leaders Class.

PLC

Polymer Liquid Crystal.

PLC

Programmable Logic Controller.

PL/C

Programming Language - { Cornell | Compiler }. That is, the PL/I compiler written at Cornell University (the ambiguity in the expansion of the C in the acronym was official).

PL/C implemented only a subset of PL/I. This was a feature. PL/I was an enormous language, and PL/C was considered useful pedagogically. The usual claims were made on its behalf: fast code, fast coding. Introduced in 1972, I think. Obsolete.

plc, Plc, PLC

Public Limited Company. A kind of corporation with publicly held ownership (stock) and liabilities limited legally. (This limit does not prevent it from going bankrupt.) Abbreviation popular in Britain.

PLCC

Plastic Leaded Chip Carrier. A (typically square) chip package with leads on all four edges. It's suface-mount technology: leads are intended to attach directly to a PC board; 64 leads is typical. (Cf. pin through a hole.)

It is easy to get confused about the L's appearing in PLCC and CLCC. In ``PLCC'' the ``L'' stands for leaded, and serves to distinguish this plastic package from some others which are similar in general outline but have pins on the bottom (pin-grid arrays). The PLCC also has J-bend leads, while the PQFP (quad flat-pack) has gull-wing leads. There are no ``plastic leadless'' packages for chips, because plastic melts or burns when you solder the contacts directly against the body of the package. In contrast, the ``L'' in CLCC stands for leadless, and since there are no leadless plastic packages this is also abbreviated ``LCC.'' The ceramic analogue of the PLCC is the Ceramic Quad J-Bend (CQJB).

National Semiconductor publishes some specs on the web. Their illustration is at right.

PLCO

Prostate, Lung, Colorectal, and Ovarian (cancer).

PLCP

Physical Layer Convergence Procedure. Mapping of cells to a specific physical transmission medium.

PLD

Programmable Logic Device. Generic term for devices like the PAL's and PLA's.

PLD

Pulsed-Laser Deposition.

PLE

PhotoLuminescence Excitation spectroscopy.

PLE

Piecewise-Linear Expression.

Please Excuse My Dear Aunt Sally

A mnemonic for a hierarchy ordering the operations in algebraic expressions: Parenthesis, Exponentiation, Multiplication, Division, Addition, and Subtraction.

Please wait.

Please wait longer than you expected.

Plexiglas

A 1935 Rohm & Haas trademark for PMMA, q.v.

PLHIV

People Living with HIV. Implicitly: asymptomatically. When they develop symptoms they become people living with AIDS.

PL/I

Programming Language One. Also written PL1 (particularly in JCL, to avoid the punctuation) back in the days when it was written at all. A high-level general-purpose programming language like Fortran, but not as popular, from IBM. If you can find someone who still programs in this language, just say ``Oh, Fortran with semicolons.'' They just love that.

The first PL/I compilers were available in around 1968. PL/I is a ``structured programming language.'' That means it's a sect of the I-hate-GOTO cult. Structured programming was hot in the seventies the way object-oriented (OO) programming was hot in the nineties. Never mind: learn what's available, use it, and don't complain. All useful programming languages suck until they become familiar, and then they become obsolete.

PLICE

Programmable Low-Impedance Circuit Element. Proprietary Actel antifuse. They've put a description on line. Here's their overall illustration.

PLIF

Planar Laser-Induced Fluorescence.

PLL

Phase-Lock[ed] Loop. Invented by Robert Dicke. Digital version is DPLL.

PLLS

Papers from the Leeds Latin Seminar.

PLMA

Private Label Manufacturers Association. Has one of those private: members only sites. According to their 1999 Private Label Yearbook, store brands account for 19.9 percent of sales in supermarkets; 13.4 percent of sales in drug stores; and 11.8 percent of sales in mass merchandisers, and are now a $43.3 billion industry. All the percentages have been climbing slowly, and these are all-time highs.

PLO

Palestinian Liberation Organization. Founded by Egyptian President Nasser in 1964. Currently the property of Yasir Arafat, trained as an engineer in Egypt, who is reported to be in poor health.

Political opinion? How is this opinion?

PLO

Permanent Latrine Orderly.

The term occurs in ``No Time for Sargeants'' (1958, based on a novel by Mac Hyman). Will Stockdale, played by Andy Griffith, is a yokel drafted into the USAF. He receives PLO punishment.

P.L.O.

Please Leave On. Instruction to janitors, written on school chalkboard. (According to one informant.)

PLOKTA, plokta

Press Lots Of Keys To Abort. Normal human reaction to program run amok.

plomb

A filigreed silver serving tray. Well, that's my best guess, anyway. I often hear of people ``carry[ing] it off with a plomb,'' though it's never very clear what ``it'' is. The plomb is never described either. But though I don't know what it is, it certainly seems to have a lot of je ne sais quoi. Great heaping helpings of je ne sais quoi, in fact, but other than that, I don't really know what.

*plonk*

To plonk someone on Usenet is disdainfully to drop the person's email address into one's killfile. That's according to the Jargon-file entry. For alternative senses, see the next entry.

plonking

Going on at stupefying and inexorable length, point by point by point, without any sense of humor or proportion, about any topic under discussion. Plonking has nothing to do with the rightness or wrongness of the arguments advanced, but refers solely to their boringly soporific effect, very often produced by the solemn and endless reiteration of the obvious. It's like plodding, but with a tinnier echo.

I having encountered the above-defined sense repeatedly in mailing list usage, and it appears to be closely related to the British slang term plonker meaning `someone who behaves stupidly,' an earlier sense attested by the Jargon-file entry. The Jargon file reports an almost opposite sense as widespread on Usenet by 1994 (see *plonk*). As the further senses listed by the OED indicate, the word has a moderately broad semantic range. I think the simplest way to cope with this word is to recognize that it is evocatively onomatopeic, suggesting the sound of something hard and something soft colliding. This goes some way to explaining more than just the variability of its meaning. It is thus also naturally associated in some way with sexual intercourse and with something inappropriately inanimate (a drunk hitting the ground, say).

The natural sound of plonking, or perhaps the resemblance to plunking, suggests the first time one hears it that one has heard it before. This may partly explain an aspect of the word's use as I have encountered it. The term generally is used in agonistic situations, of course. Almost every time, an element of the discussion is one party's accusing the other party of not understanding what ``plonking'' really means.

I'm as tired of this entry as you are.

PLOW

Punk Ladies Of Wrestling. I might pay cash to see a face-off with a Zamboni.

PLPC

Physical Layer Convergence Protocol.

PL/PD

Personal Liability / Property Damage. Insurance numbers.

PLRA

Prison Litigation Reform Act of 1996.

PLS

Partial Least Squares (method).

PLS

Physical Layer [PL of ATM] Signaling.

PLS

PLasma Subsystem. On NASA Galileo space probe.

pls.

PLeaSe. Usually the interjection or adverb is abbreviated, and not the verb.

PLS

{ Preliminary | Primary } Landing Site.

PLS

Professional Land Surveyor or Principles and Practice of Land Surveying. The latter is the name of an exam one must pass to be board-certified as the former in the US. The exam is administered by the National Council of Examiners for Engineering and Surveying (NCEES, q.v.), which administers corresponding exams in various Engineering disciplines called the PE (q.v.) on a different day. Preliminary to the PE and PLS exams are the Fundamentals of Engineering (FE) and Fundamentals of Land Surveying (FLS) exams, respectively.

See also the Land Surveyor Reference Page.

PLS

Program of Liberal Studies. A Great Books curriculum that you can take as a major at Notre Dame. The program originated in the invitation of Otto Bird, a Great Books booster, uh, scholar, to Notre Dame in 1949. Professor Bird inaugurated a General Program in Liberal Studies in 1950, a four-year program requiring study of a ``several'' languages, as they say (French and Latin). There was resistance from other departments jealous of their academic turf, and some resistance based on the fact that some of the Great Books were on the Roman Catholic Church's index of prohibited books. (Permission had to be obtained from University President John Joseph Cavanaugh. I guess the principle of subsidiarity does not extend down to the university-program level. It's a convenience in this case that lists of Great Books changes only glacially.) Against the regular departments' resistance, however, the program was strongly supported by Father Cavanaugh (who had invited Bird and other Great Bookies to Notre Dame) and by Father Theodore Hesburgh, who took over the ND presidency a couple of years later. Father Hesburgh, president for thirty-five years, is a local celebrity and the only person I know who ever had an ``AA'' parking hangtag.

In 1954, the university introduced a common set of freshman course requirements, and the PLS, like all the other majors, was reduced to three years. Because PLS is very inward-looking -- i.e., because it taught 85% of the courses it required -- PLS felt that it was especially hard-hit by this change. Then again, the talk-and-write emphasis of the first year program led more smoothly into PLS than into, say, physics. (The First Year of Studies was formalized and restructured in 1962, getting its own dean and becoming the official major of all freshmen.)

People who prefer not to acknowledge the decline of academic standards, and of plain old competence, lean heavily on the crutch of denial. Some claim that PLS is essentially unchanged since it began -- a few books gone, a few books added. Here is what Otto Bird had to say on this head in 1991:

I do not think that the program today is as good as it was in its first years. In theology and philosophy it has been watered down so that it no longer studies as intensively and extensively as it once did the writings of Plato and Aristotle, Saint Augustine and Saint Thomas. It has opened its readings to classics of the Orient, thereby further diluting its study of the Western tradition. There is also less study of logic and mathematics than there used to be and so less in the way of discipline and rigor. More attention is given to the fine arts. As a whole, the program is less "intellectualistic" than it was in the beginning.

PLSS

Portable Life-Support System.

PLT

PLaTelet. Red blood cell.

PLT

Power Line Transient.

plug

The conducting material in an integrated circuit (IC) via.

Plumbers' Poker

A flush beats a full house.

plum pudding

When the musical ``The Wizard of Oz'' opened in Chicago in June 1902, it was an instant hit. During the intermission L. Frank Baum went to producer Fred Hamlin's office and recommended that David Montgomery (Tin Woodman) and Fred Stone (Scarecrow) be signed for a five-year run. Hamlin agreed. During curtain calls there was a clamor of ``Author! Author!'' Baum came down and delivered a speech that was reported in the newspapers (and which I have cribbed from the source cited at the item linked above):

Kind friends, thank you for your enthusiasm. It is heart-warming. You have been generous enough to call for the author, but I do not need to remind you that he is only one of many whose efforts you are enjoying tonight. If you will pardon a homely comparison, our play is like a plum pudding, which combines the flavor of many ingredients. The author contributes only the flour--necessary, of course, but only to hold the other good things together.
    What would The Wizard of Oz be without the spice of Paul Tietjens' wonderful music or the brilliant scenery of Walter Burridge; the skill of that master stage chef Julian Mitchell; the golden touch of Manager Fred Hamlin, and above all, our agile comedians Dave Montgomery and Fred Stone, and the plums and peaches of our talented stage company? All of us are happy you have enjoyed the show, and we hope that you and your friends will be back for a second helping.

Here's an old-style recipe for plum pudding that uses plenty of flour. Notice the absence of plums. Plum and prune were roughly interchangeable terms in the 16th and 17th centuries, both ultimately derived from the Latin pruna -- the latter via French and the former a word already present in Old English. The change of pr to pl occurred very early in the Germanic borrowing of this word (apparently via pfr --> pfl or phr --> phl), and was adopted from English into Celtic languages. The nasal has wobbled. The Classical Greek cognate had mn, which became n apparently under Latin influence. Most Germanic languages use m, and German influence may explain the form prume found in south-east French dialects. The standard French form is prune, Portuguese has pruna and Italian prugna (gn represents, as in French, the palatalized en written ñ in Spanish). The plum tree (Prunus domestica) is prugno in Italian. I don't know if this (female fruit, male tree) is a pattern in Italian as it is in Spanish (cf. Banana).

Prunes have generally been dried plums or other fruit, but as Baum's speech suggests (see below), the separation in meanings was still not complete at the beginning of the twentieth century. Hence the expression ``dry prune'' was used. Even worse, the expression ``French plum'' has been used for prunes from France. (Because ``French prunes'' are plums?)

Plum pudding was originally made with what we'd call prunes (at least I'd call them that), though these were gradually replaced with other dried fruit: raisins (or, as in the recipe cited, currants). Maybe they switched fruit because too many people got confused and used fresh fruit when the recipe called for prunes. You really ought to read our pasa entry.

Prune is a mild laxative, but evidently some people consume prunes as food.

plural nouns in stock Spanish terms

Spanish has many idioms and compound nouns that use plural forms where not only English and German, but cognate Romance languages like French, Italian, and even Portuguese typically use singular forms. Of course, language is ultimately conventional, and broad conventions may arise from small, essentially random causes. Nevertheless, this is the sort of thing one suspects one might find a cause of, or reason for. (There: did it twice.) This plurality in Spanish is quite singular, and as Sherlock Holmes noted, singularity is almost invariably a clue.

So here is a collection of clues. In the following, the language name is underlined if its term uses a plural form. Ideally, in each cluster the terms would be semantically equivalent -- ``translations of each other.'' Since the semantic fields don't line up exactly, this is impossible. Instead, the terms are the usual translations of the term in boldface (so far that's been the English term of the cluster).

• Spanish: buenos días
  Portuguese: bom dia
  Italian: buona mattina
  French: bonjour
  English: good morning
  German: guten Morgen
  


• Spanish: buen día
  Portuguese: bom dia
  Italian: buon giorno
  French: bonjour
  English: good day
  German: guten Tag
  


• Spanish: buenas tardes
  Portuguese: boa tarde
  Italian: buon pomeriggio
  French: bonjour
  English: good afternoon
  German: guten Tag
  


• Spanish: buenas noches
  Portuguese: noite boa
  Italian: buona sera
  French: bonsoir
  English: good evening
  German: guten Abend
  


• Spanish: buenas noches
  Portuguese: noite boa
  Italian: buona notte
  French: bonne nuit
  English: good night
  German: gute Nacht
  


• Spanish: paraguas
  Portuguese: guarda-chuva
  Italian: ombrello
  French: parapluie
  English: umbrella
  German: Regenschirm
  


• Spanish: parabrisas
  Portuguese: pára-brisa
  Italian: parabrezza
  French: pare-brise
  English: windshield
  German: Windschutzscheibe
  


• Spanish: lavaplatos
  Portuguese: lava-pratos
  Italian: lavapiatti
  French: lave-vaisselle
  English: dishwasher
  German: Spülmaschine
  

We're working on, or thinking about, ``sweet dreams,'' memoirs, ``con malas ganas,'' clothesline, and some related items.

PLUS

Parent Loans for Undergraduate Students. Designed to make up the difference between the Expected Family Contribution (EFC) to the cost of a student's education, and the actually possible family contribution. [Get information from the government or from a university resource (CMU).]

plus size

Women's dress size 12 or above. According to an article on Emme Aronson in the New York Times (1997.2.12, Living Section), 60% of women in the US and 66% of women in Australia wear plus-size clothing. Emme Aronson, a 33-year-old Ford model, was at that time the world's highest-earning plus-size model, 5-foot-11, 190 pounds, dress size 14 or 16, shoe size 11. She was pushing her just-published book, True Beauty: Positive Attitudes and Practical Tips From the World's Leading Plus-Size Model. In 2004, I saw her hosting a TV show about fashion make-overs or something.

PLUTO

PipeLine[s] Under The Ocean. Not a generic acronym for any such, but the name of a project to supply motor fuel (``gasoline'' to us Yanks and ``petrol'' to the Limeys). The first ``major PLUTO'' in use was a set of four pipelines laid from the Isle of Wight to Cherbourg in Normandy, to supply gasoline to Allied forces after D-Day.

plutoid

The embarrassingly stupid name ordained by the IAU in 2008 for any dwarf planet beyond Neptune that has enough mass for its self-gravity to give it a near-spherical shape. Oh, and it also shouldn't be too dim, I hear. The satellite, that is. The IAU can be very dim. Cf. scientoid.

According to the official definition that was sprung on the scientific community on June 11, 2008, ``[p]lutoids are celestial bodies in orbit around the sun at a distance greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighborhood around their orbit.'' It's a sloppy definition, but a sloppy definition may suffice if there are no borderline cases.

It happens that as this nomenclature is being perpetrated there are two named plutoids (Pluto and Eris) and at least a couple of plutoids that are in the process of being named. With so few yet, there shouldn't be too many borderline cases... unless you count Pluto. Pluto is periodically within the orbit of Neptune. Also, Pluto should really be called a binary plutoid system, since its moon Charon is comparable to Pluto in size. Regarded as such, it's not very spherical at all. So Pluto isn't a very good example of the class of objects named after it.

They should be called erisoids; Eris was named for the Greek goddess of strife and discord. Then Pluto can be like Ceres, sui generis. (Ceres is not an asteroid because it's too big, not a plutoid because it's too close to the sun, and not a dwarf planet because that category has been eliminated -- which is just as well because other astronomical dwarf foos are foos themselves, and there's no big lobby to promote Ceres to planetary status.) There are many sensible solutions to this growing and nonexistent problem, and they are all less likely to be adopted than various unsensible solutions, one of which will probably be promulgated after another couple of years of secretive cogitation.

pluton

A region of magma injected into the crust, but not breaking the earth's surface in a volcano. Common above the edges of melting plates at subduction zones.

Why gold (Au) is often found with quartz and pyrite:

A pluton would typically have temperatures of a couple of thousand degrees C. The porosity of rock is still maybe a per cent at ten kilometers depth, maybe 5% at five kilometers, so there's a lot of water down there, and it reaches temperatures of a few hundred degrees Celsius. The water above a pluton forms convection cells: hot water directly over the pluton rises, while cooler water further away falls in the usual way and diffuses into pores nearer the pluton, where it is heated and rises. (The heating caused by the pluton fractures the area around it, increasing the porosity and thus pulling in water from around the pluton.) Before it cools, the pluton is estimated to cause the water volume to cycle a few thousand times. (One of the major unsettled questions is what fraction of the water in circulation is originally ground water, and what fraction is water from the top of the subducted plate.)

The solubility of most room-temperature solids increases with increasing temperature. This trend is quite dramatic for quartz, which is in equilibrium with silicic acid at part-per-million concentrations at room temperature, but already has a saturation concentration approaching 0.1% at a mere 300 °C. Similarly, gold and iron (as hydrosulfides and in other compounds) are dissolved in the hot water over the pluton. Near the surface, where the superheated water cools and spreads, its solutes precipitate. This includes quartz and pyrite, and gold.

Silver is found with lead ore (galena) in much the same places and for similar reasons. The main silver mines of European antiquity were at the edges of the European tectonic plate: Laurion in Greece and various places in Spain and England. Similarly, the richest gold mines were in Ireland.

Incidentally, NaCl, table salt, happens to be an exception to the solubility trend: its solubility is remarkably constant as a function of temperature.

PLV

Pitch-Line Velocity. The velocity of a gear at the radius of its pitch (its teeth). The velocity of any point on an object rotating about a fixed center equals the product of the distance to the center (the radius) times the angular velocity (inverse of the time needed for the object to rotate by an angle of one radian). Equivalently, it equals the circumference at the given radius times the circular frequency (revolutions per unit time).

PLZ

Polish (.pl) Zloty.

PLZ

PostLeitZahl. German ZIP code. Hey, that's the same abbreviation as the neighboring Poles use for their currency unit! What are they trying to say here, huh?

PLZT

Pb:La Zirconate Titanate. When not abbreviated, it's normally written ``lanthanum-modified lead zirconate titanate.'' Less often, this is called ``lanthanum-doped lead zirconate titanate.'' I suppose the ``doping'' term is avoided because a typical doping level is 10 or 17%. It's more like an alloy. PLZT is a dielectric material with a substantial electro-optic effect, proposed for various applications since the 1970's. I'm not sure about the extent of implementation or commercialization.

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