H h

Following common practice in thermodynamics, the upper-case letter H represents the extensive quantity (enthalpy) and the lower-case letter h is used to represent one or another intensive quantity (a ``specific'' enthalpy: the enthalpy per particle or unit mass, say, in units of calories per mole or per gram, or whatever else is needed or convenient).

The enthalpy of any homogeneous system of energy E and volume V at pressure p is given by

Enthalpy is a useful quantity to define theoretically, and one that can be measured rather directly in experiments, for processes that occur in constant-pressure environments, if and pretty much only if mechanical work by volume change is the only kind of work performed on or by a system. In this case, the differential of energy can be written (with T and S the temperature and entropy) as

Note therefore that since volume is positive, increasing pressure under adiabatic conditions increases enthalpy. The exact differential for enthalpy yields some obvious identities in the usual way. (In particular, the equality of the two cross-partials is called a Maxwell relation.)

For systems in which other kinds of work W can be done, it is generally possible to represent dW by a sum of products of the form FdQ, where each F is a generalized force and each Q its conjugate (generalized) coordinate or displacement. (It is true that these may refer at the microscopic level to mathematical objects that are not ``real-valued'' in the relevant sense, but thermodynamics is about macroscopic variables, and them's real, so get a life.) One can thus define a generalized enthalpy by adding a product FQ for each force. This isn't a very common practice, but the obvious applications are magnetic and dielectric systems, and elastic systems under some constant nonisotropic stress.

Chemists now represent energy fairly uniformly by E, but physicists often use U. That is a helpful hint that you should be watching out for a different H, the Hamiltonian, described in an entry close below. If you see it, you are in the realm of statistical mechanics, which is basically the concrete microscopic foundation of thermodynamics. Another symbol-table conflict between thermodynamics and statistical mechanics is at p. This is less of a problem because stat. mech. p is the length of a vector p, and vectors have a distinctive font style, but nevertheless it is often convenient to represent pressure in stat. mech. by a capital P. (Just don't mistake it for the magnitude of the dielectric polarization vector, okay?) In statistical mechanics, the thermodynamic quantities one evaluates most directly are free energies. Moreover, constant-volume calculations are usually more convenient than constant-pressure. Hence, enthalpy and Hamiltonian symbols don't bump into each other very much, even though they describe the same physical systems.

What, you want to know more?! Look, it's been a long day. Why don't you see if you can figure something out from the FGR, cumulant expansion, Liouville, and RMT entries?

You could try just saying ``aitch.'' It's different from the names of all the other letters.

Harlan Ellison has observed that the two most abundant things in the universe are hydrogen and stupidity.

The consensus of sources, once corrected for numerical typos, appears to be that the Aurelian walls of Rome had a length of 18,837 m (or km, if you insist on reading the comma European style) and enclosed an area of 1373 ha (3393 acres).

See also the Hardwood Manufacturers Association (HMA).

Just the other day I was hanging out at Dee'S Donut Shop with my pals on the acronym police. Pops (a veteran on the force since the days of cast-iron punctuation) was lamenting bitterly: ``I can never get over how some people are always getting in trouble when it's really so easy to stay on the right side of the law! Sometimes all it takes is an And or a little rewording. Failure to obey sound acronym construction rules is so rationally inexplicable that it can only be a disease. Somebody ought to study that biobehaviorally.'' The bad guys think they're clever, but nothing gets past the men in pencil blue. ``Information Transfer'' for a newsletter? Who do these people think they're fooling? It's got recherché backronym written all over it.

A completely distinct Spanish hacha, now regional and rare, means `torch.' This word, like the Galician-Portuguese facha or facho, is thought to be derived from a variant form, probably fascula, of the Latin facula, `small torch,' diminutive of fax, `torch.' (It is less probable that the hard cee of facula would have evolved into a ch, though there are other possibilities.) The idea is that the -sc- in the presumed fascula would have arisen from confusion of Latin fax with fascis, `bundle,' since torches often consisted of bundles lit together at one end. (A similar conflation, or simply combination of meanings, occurs with the English term for a bundle of twigs or branches normally intended for fuel: faggot.)

That word fascis, in the sense of bundle, has another association with axes. In ancient Rome, the power of punishment was symbolized by a bunch of sticks of uniform length, bundled to form a cylinder surrounding an axe, with part of the blade protruding. Ceremonially, lictors carried these before superior magistrates as symbols of the magistrates' power. (In this context the word usually occurred in the plural, which is fasces in the nominative case.) The symbol was originally used by the Etruscans, and the Latin Romans kept the symbol after they booted their Etruscan rulers.

The Latin word fascis gave rise to the word fascio (plural fasci) in Italian, still in the sense of a bundle of rods or sticks. The fascio was again (but without the axe) adopted as a political symbol in late-nineteenth-century Italy, on the strength of the metaphorical notion that though individual sticks are weak, there is strength in unity. From the symbol, the political groups themselves came to be called fasci. The term was eventually monopolized by the party created by Benito Mussolini during and after WWI. For this rightist party, which drew some authority from the notion that it continued or restored ancient Roman tradition, the association with the ceremonial Fascis of Rome was also valued.

I should probably say something about the word axis, since that word was used by Germany and Italy to describe their political (from 1936) and military alliance (from 1939 and the start of WWII). The idea was that the alliance was a metaphorical common pivot or fulcrum, not that you could connect the two countries by a straight line. Later, Imperial Japan was added to the axis, geometry be damned. It turns out that just as Spanish has two kinds of hacha, with the sense of axe or hatchet prevailing, so English has had two words axe (also spelled ax), the same sense now prevailing. The other sense of ax was of axle or axis, derived from a common Germanic root (cf. modern German Achse) related through Indo-European to Greek áxôn and Latin axis.

(That Erétria was an Ionian colony on the Aegean island of Euboea, near the Attic coast. There is also a nearby modern town of a few thousands by the same name, and another modern Eretria on the Greek mainland, in western Magnesia. The similarity of the name Eretria to that of the country of Eritrea is very probably coincidental. The latter is derived from the Latin name of the body of water it has a coast on: Mare erythraeum, literally `Red Sea.')

But to get back to silver, that English-v/German-b correspondence works reasonably well for noninitial consonants, incidentally. In addition to silver/Silber, one can adduce carve/kerben, cleave/klieben, fever/Feber, give/geben, have/haben, heave/heben, knave/Knabe, live/leben, love/lieben, over/über, seven/sieben, and starve/sterben [follow link for discussion of a semantic shift here], etc.

Typically, this works for cognates going back to proto-Germanic. In many cases one can no longer make the correspondence because a necessary cognate is missing on one side or the other. For example, leave had cognates in High Germanic dialects at least up to 1000 AD (some may yet survive in local dialects), but apparently no straightforward reflex of these survived into Modern German. A cognate verb bleiben (`stay, remain, be left') did survive. This is a contracted (``syncopated'') form of a compound that would otherwise be written beleiben. English had cognates belive and beleave, but they petered out of use in the fifteenth century.

The same correspondence holds for loans from a third language, if they occurred early enough. The only such example above is fever, from the Latin febris.

Sometimes there is only a one-kanji difference, but one is still suspicious. For example, there is a two-kanji word fujin that means `woman, lady.' With a different first kanji that also happens to be pronounced fu, one gets a different word fujin that means `wife.' (The common final element -jin means `person,' as in gaijin.) If the second word fujin corresponded closely in meaning to the English word wife, then a famous punchline would go something like ``that was no fujin, that was my fujin! As it happens, this wouldn't work because fujin only refers to the wife of the speaker or the writer. The wife of the speaker is referred to by a sort of first-person version of the word: kanai. This is not the only instance in Japanese where the choice of noun carries the sort of person information that pronouns and verbs carry in European and Semitic languages. Japanese verbs are not conjugated for person or number, and Japanese personal pronouns are often omitted. (Also, it is perfectly acceptable in Japanese conversation to use one's own name instead of a personal pronoun equivalent to I or me [typically watashi].)

Often you have to suspect neologistic malice. It strikes me as needlessly inconvenient that the word for comet and the name of the planet Mercury are both suisei -- a coincidence because the sui morphemes arise from two unrelated kanji. I suspect that a certain element of mischievous choice is involved. It's hard not to suspect that there isn't some coy significance in the fact that fusai is the pronunciation of totally unrelated words meaning `married couple' and `debt.'

When you go beyond exact homophones to approximate homophones and similar words, the list of suspicious coincidences grows. Shujin, for example, has the meanings of `owner, master [or mistress, as the female form of master], husband.' Don't think too hard about that, but consider that with a different initial kanji one has shûjin means `prisoner.'

If HAI is pronounced as ``high'' then it is a homophone of a Hebrew word meaning `life.' (That word is typically transliterated chai, but in European languages one usually does not distinguish phonemically among different aitch sounds.) Hai is also the standard transliteration of a Japanese word that means `yes.' (A lot of the time it really just means `I'm listening' -- sort of like ``yes, dear'' but for use in all social situations.) A more informal version is ihai. And be careful how you answer a question, if the question states a negative proposition.

``Rational'' is a loaded word pointed at pharmaceutical companies, not doctors. ``HAI promotes the rational use of medicines: that all medicines marketed should meet real medical needs; have therapeutic advantages; be acceptably safe and offer value for money.''

HAI Europe is part of something called HAI, but there's no website for HAI, q.v.

Although both /g/ and /k/ sounds occur in Korean, the distinction is not phonemic. That is, they are allophones. The emic perspective is probably best understood in terms of Hangul, the featural script of Korean -- the standard script. Hangul is written in blocks designed to resemble Chinese Han characters (logographs), but each such syllable block can be analyzed in terms of component characters called jama, which may be deformed somewhat to fit the block. (I could have just called the jama ``letters'' and let it go at that, but I figured I'd make trouble instead.)

The system is called featural because the forms of the jama illustrate schematically (or at least try to) major features in the articulation of the sounds they represent. Thus, the symbol for g/k is shaped like a capital Greek gamma (but facing left) not for sentimental xenophilic reasons, but to represent the shape that the tongue makes, viewed from the side, in the articulation of a velar consonant. An extra line is added to this symbol to indicate aspiration and represent the related affricate /k^h/, and a doubled form is used for a tensed or faucal version of the sound.

The velar stop takes voicing by assimilation, and so its sound in hagwon is indeed /g/. There are a variety of different Romanizations of Korean, with varying degrees and domains of acceptance de jure or de facto. Some use g to indicate voicing of the k/g character. Some use g preferentially for the k/g, even in cases where it is unvoiced, in order to save k (possibly with kk) for the other velars. In the latter case, hakwon is the appropriate Romanization.

In the movie, as HAL is being decommissioned by surviving crewman Dave Bowman, it says

I'm afraid. I'm afraid, Dave. Dave, my mind is going. I can feel it. I can feel it. My mind is going. There is no question about it. [Here HAL sounds a bit like George H.W. Bush.] I can feel it. I can feel it. I can feel it. I'm a...fraid. Good afternoon, gentlemen. I am a HAL 9000 computer. I became operational at the H.A.L. plant in Urbana, Illinois on the 12th of January 1992...

There's a pentium version of the story as well.

The Halaka language has virtually no productive inflections. Although its phonology suggests a Slavic influence, Halaka is not an Indo-European (IE) language. Thus, the resemblance of its name to the Hindi word halka, (`lightweight') is probably accidental. [Note, however, that the first alphabetic writing system for Sanskrit, believed to have arisen from an Aramaic alphabet, was almost a syllabary, with the default that all consonants were followed by a vowel a : halka --> halaka (a common current pronunciation in the southern, Dravidian-speaking regions of India). Hindi is in the Sanskrit subfamily of IE languages.] There is also no apparent relation with the Hebrew halakha, `the path,' which conventionally refers to the totality of oral and written Jewish law. As the only extant member of its language family (Obnac), Halaka may in fact be called a language isolate.

Today, among an estimated -34 million speakers worldwide (1990), there is already 85% literacy in the romanized (i.e., latin-character-based) orthography. A valuable and comprehensive Halaka <--> English translation dictionary was once available online, but Scott Bordelon has apparently decided that the joke was getting old. Yahoo, of course, has yet to notice that anything is amiss.

I can't take it anymore! I confess! It's lies, all lies!

There, I feel much better now. Please resume your suspension of disbelief.

You know, the path thing is a widespread pretense of religions. Just as in Judaism the law is called the way (halakha), so Christianity has John 14:6 (``I am the way, the truth, and the life''). Path imagery has been popular in Christianity, hence special use of words meaning traveler. (See, for one example, the book Pilgrim's Progress described at the V.F. entry.) Various actual pilgrimages are optional elements of Christian devotion, and in Islam a pilgrimage to Mecca is the obligation of every Muslim who can afford it. The English word Taoism comes from tao or dao, meaning `way,' which stands for the basic, eternal principle of the universe that transcends reality and is the source of being, non-being, and change. That would appear to about cover it. Buddhism has two major schools; the extant one is called Mahayana, Sanskrit for `great vehicle.' Followers of Mahayana dubbed the other school Hinayana, `lesser vehicle.'

Half an odd integer. A physicists' term for the quantum numbers of various angular-momentum-like observables. Obviously, half an even integer is also an integer. The point is to distinguish the numbers that are half-integers but not integers. (These are associated with fermions, q.v.)

There are a number of important angular-momentum-like observables, to be discussed below roughly in order of increasing abstraction. This material is normally covered at various different stages in a physics curriculum, so many readers will find that the going gets unfamiliar or tough rather quickly.

A system with a well-defined angular momentum or algebraically similar observable will have a ``good quantum number'' describing it. The most commonly discussed observables of this kind (with the usual variable designation in parenthesis) are

orbital angular momentum (L)

This is the ordinary angular momentum defined analogously with classical angular momentum in terms of position and momentum operators. The classical angular momentum vector L for a rigid body points along the instantaneous axis of rotation (direction according to right-hand rule). The rotation degree of freedom is bounded (I mean -- what goes around comes around) and, more or less as a consequence, the associated observables are discretely quantized. (I.e. the quantum-mechanical eigenstates of the operator do not take a continuum of eigenvalues. In fact, the spectrum (the set of eigenvalues) has a simple form: the possible eigenvalues of L² are L(L+1) in the natural units (aitch-bar squared), where L is a positive integer. (Please attend this fact: boldface L here represents a vector. In classical mechanics, italic L its scalar magnitude. In the same way, p is ordinary momentum and p is its magnitude. In going from classical to quantum mechanics, one takes the vectors p and L into vector operators. Because it is an observable, it is certainly possible to discuss its magnitude -- we effectively just did so in the sentence preceding this parenthetical. However, it is inconvenient to use L in the classical way, because of confusion with the quantum number L. (In atomic physics, it is often written with a lower-case l.)

The vector components of L are noncommuting: rotation about one axis followed by rotation about a different axis is not equivalent to the same operations taken in the reverse order. Noncommuting variables cannot be in simultaneous eigenstates, ... you know, I think I may be losing the people who forgot what they learned in Quantum 101, sorry ... so angular momentum eigenstates are further classified by only a single component, usually chosen as along the z axis. In natural units, the allowed values of this angular momentum component (typically labeled l_z or m_l) are the integers between -L and +L inclusive (loosely: -L, -L+1, ..., L-1, L). Hence, for an orbital angular-momentum quantum number L, there are 2L+1 states.

This is a good point to return to the idea of ``good'' quantum numbers. Obviously this is a quantum notion, but it is related to symmetry, and symmetry is a more general notion. We say that a system is spherically symmetric if the equations that describe it look the same in any direction. A spherically symmetric mechanical system can rotate in any direction. Nothing can slow or speed such a rotation, since that force would require a description that was not spherically symmetric. (Believe me, this is a lot easier to say with equations than words.) Intuitively, something that rotates faster has more energy. In fact, for simple mechanical systems, [okay, looks like this part wasn't finished]

intrinsic spin (S)

This is always well-defined for any elementary particle. The original proposal of intrinsic spin was made by two graduate students, Goudsmit and Uhlenbeck, who proposed that an internal spin variable for the electron would explain some degeneracy anomalies (i.e., there seemed to be twice as many single-electron states as one would expect; kinda important if you want chemistry to work out). In order for this idea to work, there would have to be only two intrinsic-spin states. You can see (correctly) using the formula for orbital angular momentum that 2-fold degeneracy requires 2 = 2S+1 or S = 1/2. There is no way to derive a half-integer value from an angular momentum that generalizes classical angular momentum (as above).

Goudsmit and Uhlenbeck went back to their advisor and said they had second thoughts about their idea and preferred not to publish. He told them it was too late, he'd already sent their manuscript off. In those days, journal reviewers were not so nitpicky either, and the paper went to press. Their advisor (I forget who) consoled them: they were young -- they had the right to publish something crazy. As soon as the paper appeared, H. A. Lorentz pointed out that given the known bounds on the radius of the electron, the proposed value of spin represented an angular momentum so high that the surface of the electron would have to be moving faster than the speed of light (an obvious no-no).

There are other classical-picture objections, and the basic answer to them all today is: spin is an intrinsically quantum-mechanical quantity that happens to share numerous properties (including its general algebraic structure and a proportionality to magnetic moment) with orbital angular momentum, but does not arise from particle motion that has a classical analogue. It is handy to visualize it as the spin of a particle, but strictly speaking elementary particles have no geometric extent and don't spin. (I mean: in the underlying description, elementary particles are points. The real particles they describe, of course, cannot be perfectly localized -- this follows from the uncertainty relations. The picture gets trickier with string theory. String theories are formulated in more than the usual three space dimensions, but the excess dimensions are curled up very tight -- the distance that anything can move in those other directions is preposterously short, and when you move that far, you've just circled back to where you started. Anyway, in these theories fundamental particles are described by strings -- closed loops, in fact. The particles still have at least a codimensionality of three in the higher-dimensional space, so on any human scale it is reasonable to call them point-like.)

There are now many particles (fermions) known with spins (S values) of 3/2, 5/2, and higher. However, so far these are all composite particles or excited states of other lower-mass, more stable particles that have spin 1/2. Spin-S particles have states of well-defined z-component spin (labeled s_z or m_s) with spin angular momentum values from -S to +S. (I.e., -1/2 and +1/2 for spin-1/2; -3/2, -1/2, +1/2, +3/2 for spin-3/2, etc.) [I ought to talk here about Regge analysis, a great fad around 1960. On second thought: no I shouldn't.] The term half-integer normally modifies spin, which is to say total spin quantum-number rather than a component (``ess-sub-zee''). Therefore, in practice, the half-odd integer it refers to is positive.

Isospin (I)

Contracted from the older name for this concept: isotopic spin. As an aside here, I should mention that isospin, like angular momentum and all the rest

In outline, the idea behind this is simple: protons and neutrons are particles with similar mass, and since mass is energy, they have the same energy. Now as noted above, rotation symmetries yield finite numbers of degenerate states, corresponding to distinct values of the z component of angular momentum. Introducing a completely inventing a new spin-like algebras yield finite numbers of degenerate The idea had been around even before relativity, that particles are, as we would say now, ``excitations of the vacuum.'' rotational symmetry in three dimensions have

There's more (intrinsic spin of a collection of particles, total angular momentum, etc.), but that's for another day.

The trivial nuclear example is deuterium, which can be regarded as a proton nucleus with a neutron halo (D = ²H = ¹H + n). This sounds silly on its face: you'd figure that the neutron-proton separation would determine the only sensible definition of what is `inside' the nucleus, so that neither nucleon could be outside of it, on average. However, the rms internucleon distance is an astounding 4.4 fm, so most of the time the nucleons are outside the range of their interaction. Effectively, one should regard halo nuclei as those with some nucleons that spend much of their time more than about a fermi (fm) away from any other nucleons. The large average separation is a natural consequence of the just-bound nature of the deuteron. [The scattering-length concept makes this extremely explicit.]

A more intuitive example is ¹¹Li, which looks like ⁹Li + 2n. [The numbers preceding `Li' should be superscripted. Upgrade your browser if they're not. The number in this position next to the chemical symbol for an element represents a nucleus of that atom with the given number of nucleons.] The core ⁹Li has its four protons and five neutrons in a radius of 2.5 fm. The two-neutron cloud in ¹¹Li has a radius of 7 fm.

I think that ¹¹Li marked the ``modern discovery'' of halo nuclei by B. M. Young, et al., reported in Phys. Rev. Lett. vol. 71. Afterwards, it became clear that the surprisingly large branching ratio for E1 decay of ¹¹Be, reported by D. J. Millener, et al. Phys. Rev. C 28, 497 (1983), could be explained simply in terms of a neutron halo.

The key salt in old black-and-white film was silver iodide, and so one film manufacturer in Rochester called itself Haloid. It later became Xerox.

Yes, yes, the city of Halle in Germany got its name from salt mines there.

As is common in many element groups, the lightest element is a bit of an outlier. Hydrofluoric acid, although it is extremely dangerous and corrosive, is not the strong acid that hydrochloric and hydrobromic acids are at the same concentrations.

Sometimes hydrogen is given two locations on the periodic table: its usual place at the beginning (upper left corner) and also the spot just left of helium, which is to say just above fluorine in the column of halogens. This makes an obvious sort of ``electronic'' [atomic-level] sense: there is a single unoccupied state in the highest (and only) occupied level (1s). It also makes a bit of chemical sense, as there are hydrides -- simple compounds in which hydrogen has valence -1 like a halogen. Just don't call it a halogen. (And normally, expect it to have valence +1.)

Halogen lamps are incandescent lamps that use a halogen fill gas, usually iodine or bromine, and (as is essentially universal for incandescent lamps) tungsten filaments. Tungsten atoms evaporated from the filament react with the fill gas to form tungsten halide (i.e., tungsten iodide, tungsten bromide, etc.). This compound does not stick well to glass, but tungsten halide molecules adsorbed on tungsten metal react to deposit tungsten and evolve halogen gas. These facts result in the capture and eventual redeposition of tungsten on the filament. This is called the halogen cycle, and by reducing the effective rate of metal evaporation, it reduces the principal mechanism of lamp aging. (When a halogen lamp is operated at low power, tungsten halide accumulates on the bulb surface. Operation at full power re-evaporates the condensate, clearing the glass and regenerating the filament.)

During operation, the density of the vapor must be high enough to assure that the mean free path of a tungsten atom is much less than the distance between filament and bulb. This can require fill gas that is close to atmospheric pressure. At atmospheric pressure, the boiling point of bromine is 58.8°C, so bromine fill gas condenses as a fluid when the lamp is cold. (The Br melting point is -7.27°C.) Iodine has boiling and melting points of 184.35°C and 113.5°C. In a small quartz lamp I used to have, a thin brownish film and a hardened droplet or two would be left on the inside surface of the lamp after it cooled, and would slowly vaporize as it heated.

(Normally, incandescent bulbs have nitrogen, argon, or a mix as fill gas, at a low pressure that rises to about one atmosphere at normal operating temperature. Lamps of less than 40 watts typically are just evacuated.)

A little point that was elided above is that while tungsten halides do not react and bond to glass, they may simply condense. Hence, halogen lamps must be operated with the interior of the bulb at 500 degrees C or above. (This is just one very good reason to avoid touching a halogen lamp with your bare fingers.) For a long time, halogen lamps used quartz bulbs because quartz glass was the only kind that had the necessary high-temperature strength. (Nowadays there are some alternate glasses in use.)

At the high temperatures reached by quartz bulbs, some skin oils can penetrate and degrade the glass, making it porous, admitting air, and resulting in early failure. Don't let this happen. If you touch the quartz when it is cold, then before turning it on, clean it with a solvent such as lighter fluid. (I love this recommendation. Be sure to dry it off and put anything flammable away before you turn the lamp back on.) If you touch the quartz when it is hot, just scream.

Hamas was founded in 1987, at the beginning of the first intifada or `uprising' against Israel. Hamas vows never (see jamás) to accept the existence of a Jewish state in the Middle East, and engages in terrorism against Israelis essentially anywhere. It won a majority of seats in the January 2005 elections for the Palestinian Authority parliament.

Similarly, she condemns bracketing case changes. But when I quote her writing ``bracketing such changes looks not punctilious but weird,'' you know that this is only part of a sentence. Had it been the entire sentence my quotation of it should have begun ``[b]racketing such changes....''

She concludes, ``[p]roceed blithely.'' Don't.

You know that count of entries at the thumbtabs page, that stands at about 16000 as of this writing? Well, even stupid entries like this one count toward that number.

Two out of three of us who discussed it at lunch a couple of years ago believed that the elastics on Hanes briefs had gotten weaker in recent years. (That's not a survey but an exact count.)

Here's another interesting thing about that thumbtabs page: we get dozens of visitors to that page every day who were looking for rock music guitar tabs.

1. A Dictionary of Surnames, published 1988. (Special consultant for Jewish names: David L. Gold.)
2. A Dictionary of First Names, published 1990.

Both are very useful books, but it pays to check them where possible, since a few entries, if not demonstrably wrong, can sometimes mislead. See, for examples, the pardo entry (for the Spanish and Portuguese surname Pardo) and the discussion of Hermann towards the end of the SN entry.

For other similar works, see Familienname and Reaney and Wilson.

Excellent sites to learn more: WebElements and Chemicool.

In origin, however, the word (heardlice in Old English) meant `harshly' or `bravely.' That is, it meant `in a hard manner' with an older sense of hard: `bold' or `forceful.' (The modern word hard may be said to preserve the ``passive'' senses of its etymon.) Use of the original sense of the adverb has been in a long-term decline; a more common expression of the idea is ``with difficulty.'' This sense still took pride of place in the hardly entries of Noah Webster's American Dictionary of the English Language (1828) and of Webster's Revised Unabridged Dictionary (G & C. Merriam Co., 1913, edited by Noah Porter).

The `with difficulty' sense of hardly is hardly common at all. In fact, it's not hardly common: it's just plain rare. But it's not unknown, though I'm not sure if it's hardly unknown. Anyway, here's part of a paragraph that uses hardly in two different senses. In the second instance the different senses of the word are almost opposite, and the context is needed to make clear which sense makes sense.

... In the last quarter of the seventeenth century Cartesian science was indeed expounded in some of the colleges of France, and less widely elsewhere, but dissemination of the thought of Galileo, of Bacon, and of the exponents of the mechanical philosophy owed little to university courses. Occasional examples of a university teacher having a decided influence upon a circle of pupils--as was the case with John Wilkins at Wadham College, Oxford, and Isaac Barrow at Trinity, Cambridge--hardly vitiate the general conclusion that the activities of various societies, books, and journals were far more potent vehicles of proselytization, which is supported by many personal biographies. However stimulating the exceptional teacher, formal courses were commonly conservative and pedestrian: it is curious to note that the two greatest scientists of the age who were also professors, Galileo and Newton, seem to hav been singularly unremarkable in their public instruction. If the universities could produce scholars, they were ill-adapted to turning out scientists; the scientist had to train himself. Many who accomplished this transition regarded it, indeed, as a revulsion from the ordinary conception of scholarship. The learning they genuinely prized, in their own scientific disciplines, they had hardly won for themselves. It would surely be absurd to argue that Newton was less a self-made scientist than Huyghens, or Malpighi than Leeuwenhoek, because the former had attended a university and the latter had not.

(There's also a relatively small concentration of dissolved CO₃⁼ ion. I actually had a student ask me once what the superscripted equals sign meant. It's a doubled negative sign. I might have written CO₃^2- equivalently.)

Detergent and soap molecules all have basically the same structure: NaR, where R is a long-chain organic molecule. In traditional soap, the long chain is a fatty acid. (Explanation at the saponification entry. Detergent is usually sodium lauryl sulfate, where lauryl- is a twelve-carbon carbon chain extracted from plants, and the sulfate group on the end of the chain bonds to the sodium.

In the presence of nonpolar dirt, the nonpolar end of a soap molecule buries itself in the dirt and the polar Na⁺ sticks out where it can dissolve in water. In soapy water, microscopic droplets of dirt accumulate a highly polar surface this way, enabling them to dissolve in water and rinse down the drain.

Calcium ion interferes with this process through the following competing reaction:

Ca²⁺ + 2NaR --> 2Na⁺ + CaR₂ .

1. Sterically, the carbon chains tend to surround the calcium with nonpolar dirt in such a way that it has less exposure to the water it's supposed to dissolve in.
2. In any case, calcium ion is less soluble in water.

Another effect of hard water is to prevent lathering. Lathering is simply the formation of small soap bubbles, and ``soap bubbles'' are really just water bubbles. The role of soap is only to reduce the surface tension of water so the water can form the stable thin-film surface of the bubble. Soap converted by reaction with calcium just doesn't have the same surfactant effect.

Hard water arises because water supplies often come from underground water sources -- aquifers. An extremely common aquifer material is limestone, which consists mostly of calcium carbonate. That's the reason hard water comes not only with high calcium concentration but high carbonate concentration. That carbonate is associated with another hard-water problem: precipitation of calcium carbonate. Nowadays, people notice this first in their teapots: over time, carbonate rings form around the level where the water boils. It's not bad for you and you can't taste it (although you can certainly imagine that you can). It does look bad, though, and many people throw away perfectly good teapots just because they've accumulated an unsightly ring.

DON'T THROW IT AWAY, YOU IDIOT!!!

What you do is, fill the teapot with water above the ring level, and add lemon juice or vinegar or some other acid. (I suppose any cola would do too. Those are acidified by phosphoric acid, but the sour taste of the acid is entirely masked by the sweetness.) Cook it a little bit and the acid will dissolve out the carbonate. Throw out that water now and you have a clean teapot. For a bit more on acid and scale build-up, see the L.I. entry.

The Passover seder is somewhat technically demanding and confusing. A frequent error is confusing haroset with hreyn (Russian name, adopted in Yiddish, for horseradish, ``bitter herbs'').

Now I finally have the appropriate entry for Craig's ``symbolic disputation'' joke. Later.

HARPS ``is dedicated to the discovery of extrasolar planets,'' and it has discovered most of the smallest ones. It first went into operation in February 2003.

Part of the reason for using Harvard architectures is to avoid the endless loops, file corrupts and other dangers that occur when instructions can modify themselves. There is a common notion that the von Neumann machine is somehow more powerful or capable of more general tasks than a Harvard machine. This is not true, since within any Harvard machine it is always possible to simulate a von Neumann machine which uses only the data memory. (Of course, it is also possible to simulate a Harvard architecture within a von Neumann machine.)

This entry is a mess because really, when one is talking Harvard or von Neumann architectures, one is usually discussing abstract machines, Kolmogorov entropy, and all that effete stuff about computability. So really the comments about implementation are otiose. I ought to go back and fix the entry, but I'm lazy.

When (and where) I was in grad school, people going for a Ph.D. in the Computer Science Department were really just doing an oddball sort of abstract mathematics. The joke went that the first time they ever used a computer was to word-process their dissertations. (This was before email.)

In the top tier are old private liberal arts colleges that

1. are known nationally although
2. they do not have an NCAA division I football team, and
3. are known to be ``known as `the Harvard of the South' '' by at least one dozen (12) people outside the South who are not either alumni of that school or their close relatives. (These people believe that this is the only school bearing that epithet.)

Strictly speaking, the first tier comprises only Duke and Vanderbilt, but considering that (a) they don't even have a decent basketball team and (b) my pal Marvin went there, I also include Rice University in the first tier. I further include the University of Virginia, so that if anybody tries to thin the ranks of the first tier, there will be another school that goes before Rice. To be fair, because of Rice's location (Houston) it is less well-known than Vandy (in Nashville, Tennessee) or UVA. If one were to judge by how freely and unapologetically the alumni use the epithet, then Rice would rival Duke.

The University of Virginia, the only public university in the top HotS tier, was Thomas Jefferson's last hurrah. Joseph C. Cabell (1778-1856) was Jefferson's principal strategist and assistant in founding the university. In a letter of January 22, 1820, to J.C. Cabell, Jefferson worried that Virginians educated at Harvard would turn into ``fanatics & tories.''

In the second tier are schools with only a regional HotS reputation: Emory (discussed at the S.P.D. entry) heads this list, followed by Tulane and Ole Miss (University of Mississippi).

Schools of the third tier have a qualified HotS reputation. These are schools about which it is said that ``it is said that some people call it the `Harvard of the South'.'' The epithet is usually deployed ironically or in a way that can be defended as facetious if challenged. This group is rather ill-defined; since virtually no one is willing to claim baldly that one of these schools is the HotS, the entire charade is based on rumors of mis-overheard jokes. Most of these schools have to be identified as Foo College in Bar City, State_Name_Here. Many of the third-tiers are members of the Associated Colleges of the South (ACS), particularly Centre, Millsap, Morehouse, and Sewanee (``University of the South''), and many of the remaining ACS schools qualify marginally (Davidson, Furman, Hendrix, Rollins, Trinity (TX)). Non-ACS third-tier HotS schools are Fisk, Hampton University (Hampton, Va.), Livingstone College of Salisbury, N. Car. (main claim to fame: ``W.E.B. DuBois once referred to Livingstone as the `Harvard of the South' ''), Wofford College (in Spartanburg, South Carolina) and SMU. (Also one McNeese State University -- sports reporting, you know.)

The fourth and lowest tier of schools have bureaucratically mandated HotS ``reputations.'' For example, according to this linked news item, ``UF [University of Florida, Gainesville] administrators have designated the school the `Harvard of the South'.'' I must have missed the announcement. UT Austin has also been called a HotS. Whether this was pursuant to an administrative order I do not know, but (a) I do know that they have tried to buy a reputation by recruiting top scholars (nothing wrong with that) and (b) I have been in Austin, and it does not feel even remotely like Cambridge.

To summarize: one way or another there are two dozen Harvards of the South distributed among the states that seceded to form the Confederacy. Of those eleven states, only Alabama does not claim to have a single HotS. If you enjoy devil-may-care honesty (and I sincerely hope you do) then you'll want to read this 1996 interview of Auburn University history professor J. Wayne Flynt. My man Flynt! He delivers a coruscating jeremiad that includes this:

I think the popular culture in Alabama has a perception of a limited future. In fact, recent polls indicate when Alabamians were asked "what do you envision for your children?" in terms of their future occupations, the single largest category of response was to be in fast food. The level of local support for education is so poor that (the population perceives) there is no future in this community; there is going to be a steady collapse of community to the point where it may be too late. This brings the question can it be collectively too late for a state, and I think the answer is yes.

Then the interviewer had the gonads to ask (reading from a list, I suppose), ``Who is responsible for the success of education in Alabama?'' His answer appears to be cut off, but it begins ``That's sort of like asking who's to blame for the problems.'' I think Neil Young was on to something.

Also deserving of mention: Baylor (at Waco, Texas), the ``Harvard of Southern Baptists.'' The riffs on this idea are endless. Your next stop on the tour of these riffs is the S.P.D. entry.

J. E. Gunn, S. K. Malik, and P. M. Mazumdar: ``Highly Accelerated Temperature and Humidity Stress Test Techniques (HAST),'' 19th Annual Proceedings International Reliability Physics Symposium pp. 48-51 (IEEE, 1981).

Regarding chromosomes: ordinary human cells have 23 pairs of them. Human germ cells, as they used to be called, or gametic cells (sperm and egg cells), are haploid: they have half the usual complement of chromosomes. Cells undergoing mitosis have double the usual complement just before fission, and red blood cells have no nuclei. (Although paired chromosomes are pretty common in the somatic cells of eukaryotes, there are various organisms which exhibit haploidiploidy: males develop from unfertilized eggs and have haploid somatic cells. You think that's weird, just be glad I don't define haploidization. Haploidiploidy happens with honeybees, but not with chickens. So the egg you had for breakfast was never going to hatch into a bird, since it wasn't fertilized.)

There are a number of genetic abnormalities in humans that involve unusual numbers of chromosomes (``aneuploidy''), and a few of these are not immediately fatal. The best known is Down syndrome (an extra copy, ``trisomy,'' of chromosome 21), which modern treatment has made quite survivable. (Strictly speaking, this only accounts for about 95% of Down cases. In the translocation type of Down syndrome, extra chromosome-21 genes are inherited via DNA that has translocated onto another chromosome.)

A number of aneuploidies involve the sex chromosomes. This page lists a bunch.

Read it here now. Eventually I'll scatter this stuff to more appropriate entries.

The Mickey Mouse ears atop the "Earffel Tower" (a water tower in the Disney-MGM Studios addition to Walt Disney World, created by Caldwell Tanks, Inc.) correspond to a hat size of 342 3/8!

``Hat size'' is also a ready euphemism for intelligence. (E.g., ``they don't publish chemistry textbooks in your hat size.'')

A Hauptbahnhof is the `principal train station' of a city. Amsterdam Hauptbahnhof is `Amsterdam Central.' In June 2005 I was able to google all of three instances of Penn Hauptbahnhof, all serving as translations to German of `Penn Central Station.' Journalists, sensibly, generally avoid attempting a direct translation. Penn Central Station is the name given in various cities to the train station where the old Penn Central Railroad stopped.

The headword of an entry, in general, is das Stichwort. Der Stich is a cognate of `the stitch,' but is used for a wide variety of related penetrations -- `stab, dig, sting, pinprick.' You can think of Stichwort as `incised word.' German also has die Rubrik, and `unter der Rubrik ...' does still mean `under the rubric [of] ...,' but the word's meaning has drifted more decisively in German than in English, and now Rubrik itself primarily means `category' (figurative sense of rubric) and `[newspaper] column.' You could use s.v.

A headword, in the technical linguistic sense of a word that may be modified by an adjunct, is simply called a Nukleus in German.

The HAV nots are better off, and it is not good to give or to receive.

To purchase another of our fine products, insert more money.

There was a popular BBC program (or programme, anyway) on the English language, and I think it was in a companion paperback called The Story of the English Language or something that I read the claim that the use of ``have got to'' began in Britain and was brought back to the US by American soldiers after one or another World War. This has the following plausibility: one might expect a verb following have in a compound construction to be in the past participle form. American English preserves a few older distinctions between past and past-participle forms, among them between got (past) and gotten (past participle), that have largely disappeared in British English. Hence ``have got'' in the sense of ``have received'' is common in Britain and rare in the US. Then again, ``I've got'' in the loose but common sense of ``have'' is common in the US, so this isn't very strong evidence. (Because of the difference in participles, ambiguities differ. For example, in Yellow Submarine, the Beatles escape the Sea of Green, I think it was, when Ringo makes a discovery: ``I've got a hole in me pocket!'' In principle, if one wanted to tease apart the semantic mille-feuille, one could distinguish two main possibilities here: either he suddenly remembered a hole that was already in his pocket, or he suddenly discovered that a hole had entered into, become present in his pocket. In American English, the second sense would require gotten.)

In fact, however, the have-got-to modal was in common use in the US at least as early as shortly after the Civil War, while it was apparently not in common use in Britain as late as 1909. My evidence for both claims is in Sir William Butler: An Autobiography, which Lieut.-General the Rt. Hon. Sir W. F. Butler, G.C.B. wrote in the year before he died on June 7, 1910. The times he spent in North America included a period in 1866 when he joined the buffalo hunt in the Nebraska Territory. He describes this toward the end of chapter 6, and digresses thus:

    What impressed me most strangely about the men I now came in contact with was the uniformity of the type which America was producing--northern, southern, eastern, western, miner, hotel-keeper, steamboat-man, railroad-man, soldier, officer, general,--the mould was the same. `There has got to be' seemed to be the favourite formula of speech among them all, whether it was the setting up of a saloon, the bridging of a river, or the creation of a new State. `There has got to be' this railway, this drinking bar, this city, this State of the Union. Nobody dreamt, except when he slept; everybody acted while he was awake. They drank a good deal, but you seldom saw a man drunk, and you never saw anybody dead drunk. They sometimes shot each other, they never abused each other; they were generous, open-hearted, full of a dry humour, as manly as men could be; rough, but not rude; civil, but never servile; proud of their country and boastful of it and of themselves. That day and evening, and all the other days and evenings I spent at Fort Kearney, were the same--good fellowship, good stories round the festive board at night, hard riding and hunting all day over the glorious prairies.

It's probably worth noting that there is a certain celebratory tone in much of Butler's writing (particularly in his biography of General Napier), but he is not uniformly laudatory. The business about story-telling reminds me of some observations Gertrude Stein had in Wars I Have Seen (pp. 248-9). This is also an autobiography, like pretty much all of her books, and it was written after the liberation of France, and so also in the year or two before she died.

Gradually as the joy and excitement of really having Americans here really have them here began to settle a little I began to realise that Americans converse much more than they did, American men in those other days, the days before these days did not converse. How well I remember in the last war seeing four or five of them at a table in a hotel and one man would sort of drone along monologuing about what he had or had not done and the others solemnly and quietly eating and drinking and never saying a word. And seeing the soldiers stand at a corner or be seated somewhere and there they were and minutes hours passed and they never said a word, and then one would get up and leave and the others got up and left and that was that. No this army was not like that, this army conversed, it talked it listened, and each one of them had something to say no this army was not like that army. People do not change, no they don't, when I was in America after almost thirty years of absence they asked me if I did not find Americans changed and I said no what could they change to except to be Americans and anyway I could have gone to school with any of them they were just like the ones I went to school with and now they are still Americans but they can converse and they are interesting when they talk. The older Americans always told stories that was about all there was to their talking but these don't tell stories they converse and what they say is interesting and what they hear interests them and that does make them different not really different God bless them but just the same they are not quite the same.

For more on Stein on Americans telling stories in France, and an indication of how all her books are autobiographies, sometimes in two different senses, see the S.O.S. entry. The issue of American cultural homogeneity is touched upon at the 5-2 defense entry, in a quote from Everybody's Autobiography (by and about Gertie, of course).

William Butler's use of the word mold is reminiscent of ``the melting-pot'' metaphor of America, popularized by Israel Zangwill's play of that name. (In Act I: ``A fig for your feuds and vendettas! Germans and Frenchmen, Irishmen and Englishmen, Jews and Russians--into the Crucible with you all! God is making the American.'') Zangwill's play was the hit of 1908, the year before Butler wrote. (The metaphor was used by others, such as Ralph Waldo Emerson, in earlier but much less well-known instances.)

The Chemical Transportation Emergency Center (ChemTREC) emergency number is 1-800-424-9300.

See the Hgb entry for a thought on the construction of this abbreviation.

The Commonwealth spelling of (Amer.) hemoglobin is haemoglobin.

The state of Bremen comprises two urban areas -- Bremen and its seaport city Bremerhaven. (The aitch might refer to Haven, `port' or to Bremen's history as a Hanseatic city; I don't know. The German word for port is Hafen, which would be pronounced the same if it were spelled Haven, and which is of course a cognate of the English word haven. Bremerhaven was founded very recently by European standards -- 1827, but spelling evolves.)

Bremerhaven is on the North Sea coast, Bremen is thirty-plus kilometers up the Weser River. All the land borders of the two cities are with the surrounding state of Lower Saxony (NI).

All together Bremen is the smallest Land, both in terms of area (404 sq. km.) and population (660,000 in the national census of 1987; 677,800 in the a local census for Dec. 31. 1996). Bremen was part of the old West Germany, and is Germany's second largest port after Hamburg (see HH).

In the same book he also explains that when pencils as we know them were first invented, they used unprocessed, natural graphite -- and the only known source of this with decent quality was a single mine at Borrowdale, near Keswick, England. This monopoly lasted for over 100 years.

I recommend using an alphabetic character from Maltese (U+0127; the letter name is ħe). Barring that, if you'll pardon the expression, there are other alphabetic characters. The version of Cyrillic alphabet used in Serbian has a small letter tshe (U+045B) that is similar. Both of these symbols have the form of a lower-case Roman letter aitch with horizontal bar through the upper half of the letter, and both are widely available in italic variants. When italicized, both would pass for ordinary hbar glyphs but for the fact that bar in hbar is a slanted stroke (upper right to lower left). Another option is Ogham letter ruis. This is less similar and less common, which is just as well: it's supposed to be at U+168F, and apparently is there on Mac fonts, but the Microsoft fonts I've checked have a grave-accented W there. Another approach is to use strike-through, but that generally puts a horizontal bar below the middle of the character line, so it looks pretty bad. Here are the approaches described:

• &#x210F;: ℏ
• <i>&#x0127;</i>: ħ
• <i>&#x045B;</i>: ћ
• <i>&#x168F;</i>: ᚏ
• <i><del>h</del></i>: h

(I use <del> because <strike> and <s> are deprecated.)

Another approach is to create the page in LaTeX (where one has \hbar) and use one of the standard conversions that generates gifs for all the formulae.

Vide AC.

``Please be aware that our mailings are scheduled well in advance. Although your name will be removed from our list immediately, there may be one more solicitation which is already on its way to you.'' [In microelectronic hardware, this sort of practice is called vectorization or pipelining.]

Morehead and Spellman, in Atlanta, are two HBCU's that are part of the Associated Colleges of the South. There's some history of Dillard University, an HBCU in New Orleans, at this AMA entry.

Ohhh -- I get it. It's the hard-to-get gambit, not-sentimental variation.

There ought to be an episode where Robin says ``Holy Bible, Batman!'' The defect of having an abbreviation HBRV is that it's bound to be misconstrued as standing for ``HeBRew Version'' sometimes.

This page is about HBT's on Silicon (Si).

``Centers.'' I'm sure there was a very good reason to use this word.

In 1992, the Greenville (S. Car.) Department of Social Services sent a termination notice to a former beneficiary. This stated in part:

Your food stamps will be stopped effective March, 1992, because we received notice that you passed away. May God bless you. You may reapply if there is a change in your circumstances.

Under proposed welfare reforms now being considered in the House of Representatives under the Republican regime, the letter would have read ``Your food stamps have been stopped effective March, 1991, because we figure you'll be dead soon anyway. May the Market have mercy on your estate. If there is a change in your circumstances, we'll call you.''

Under terms of the 1988 Democratic Party platform (by all accounts, year of the last admittedly liberal US presidential campaign), the letter would have read ``Your food stamp allocation will be increased effective March, 1993, because you haven't been eating well. May a superior rational being, if you choose to acknowledge one, empower you emotionally. If you have any material desires, please allow us to fulfil them.''

The strongest acid that any ancient civilization knew about was acetic acid -- the chemical which, as its name suggests, makes vinegar sour. (Follow the link for etymological details.) Acetic acid is not a strong acid. Over the course of centuries, mineral acids were eventually made and discovered. In 1824, the English physician William Prout demonstrated that the gastric juices of animals contain hydrochloric acid. (So much effort, and all that time the alchemists were carrying around little sacs of acid at the ends of their esophagi.) Prout's contemporaries were incredulous.

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