Eliminate, Exterminate & Eradicate

Eliminate (pronounced ih-lim-uh-neyt)

(1) To remove or get rid of, especially as being in some way undesirable.

(2) To omit, especially as being unimportant or irrelevant; leave out.

(3) To remove from further consideration or competition, especially by defeating in sport or other competitive contest.

(4) To eradicate or kill.

(5) In physiology, to void or expel from an organism.

(6) In mathematics, to remove (a quantity) from an equation by elimination.

(7) In sport, as elimination & eliminator (drag racing): category classifications. 

1560–70: From the Latin ēlīminātus (thrust out of the doors; expel), past participle of ēlīmināre, the construct being ē- (out) + līmin- (stem of līmen (threshold)) + -ātus (the Latin first/second-declension suffix (feminine -āta, neuter -ātum)).  The most commonly used form in Latin appears to have been ex limine (off the threshold).  Used literally at first, the sense of "exclude" was first attested in 1714; the now obsolete sense of "expel waste from the body" emerged circa 1795 although the general sense of an "expulsion of waste matter" is from 1855.  Eliminate is a verb, if used with an object, the verbs are eliminated & eliminating, eliminability, eliminant & eliminability are nouns and eliminable, eliminative and eliminatory are adjectives.

Exterminate (pronounced ik-stur-muh-neyt)

Totally to destroy (living things, especially pests or vermin); annihilate; extirpate.

1535–1545: From the Latin exterminātus, past participle of extermināre (to drive away (from terminus boundary)), perfect passive participle of exterminō, the construct being ex- + terminō (I finish, close, end), from terminus (limit, end).  In Late Latin there was also the sense "destroy" from the phrase ex termine (beyond the boundary), ablative of termen (boundary, limit, end).  The meaning "utterly to destroy" appeared in English only by the 1640s, a sense found earlier in equivalent words in French and in the Vulgate; earlier in this sense was the mid-fifteenth century extermine.  Exterminator actually came earlier: as early as circa 1400, the Late Latin exterminator (from past participle stem of exterminare) had the sense of "an angel who expells (people from a country) and, by 1848, as a “substance for ridding a place of rats etc) and by 1938 this was applied to a person whose job it was.  Exterminate is a verb, used with an object the verbs are exterminated & exterminating, exterminable, exterminative & exterminatory are adjectives and extermination & exterminator are nouns.

Eradicate (pronounced ih-rad-i-keyt)

(1) To remove or destroy utterly; extirpate.

(2) To erase by rubbing or by means of a chemical solvent or other agent.

(3) Of plants, to pull up by the roots.

1555–1565: From the Latin ērādīcātus (usually translated as “destroy utterly”; literally “pull up by the roots”), past participle of ērādīcāre (root out, extirpate, annihilate), the construct being ē- (out) + rādīc- (stem of rādīx (root) (genitive radicis)) + -ātus (the Latin first/second-declension suffix (feminine -āta, neuter -ātum)).  The assimilated form of ērādīcāre is derived from the primitive Indo-European wrād (branch, root) and from the same source, the native form of the same idea existed in mid-fifteenth century Middle English as outrōten (to root (something) out; eradicate).  A surprisingly recent creation in 1794 was ineradicable and within a few years, ineradicably.  Eradicate is a verb, eradicant is an adjective and noun, eradicated & eradicating are verbs (used with object), eradicable & eradicative are adjectives, eradicably is an adverb, eradication & eradicator are nouns.

Eliminate, exterminate and eradicate in the age of pandemics

In Modern English usage, eliminate, exterminate and eradicate are often used interchangeably despite differences in nuance.  This means also the wealth of synonyms the three enjoy are sometimes haphazardly used although some overlap does exist, the synonyms including: annihilate, expunge, abolish, erase, uproot, extinguish, efface, demolish, total, abate, liquidate, obliterate, trash, squash, purge, extirpate, scratch, slaughter, decimate, execute, massacre, abolish, erase, extirpate, destroy, oust, waive, ignore, defeat, cancel, exclude, disqualify, invalidate, drop, eject, expel, liquidate, omit, terminate, slay, discard & disregard.

In the (relatively) happy times before the emergence of SARS-Cov2's Delta variant, the New Zealand prime minister declared COVID-19 “eradicated but not eliminated” which did sound given that, regarding disease, the words have specific, technical meanings.  In the context of disease, eradication refers to the complete and permanent worldwide reduction to zero new cases through deliberate effort.  Elimination refers to the reduction to zero (or a very low defined target rate) of new cases in a defined geographical area, which can be any size, a province, country, continent or hemisphere.  As used by virologists and epidemiologists therefore, eradication is used in its normal conversational sense but elimination is applied with a specific technical meaning.  There is a quirk to this. The World Health Organization (WHO) certified the global eradication of smallpox in 1980 although small cultures remain in US and Russian research laboratories.  If these residual stocks are ever destroyed, the WHO may adopt some new term to distinguish between eradication in the wild and an absolute extermination from the planet.  Nobody seems now to believe COVID-19 will ever be eliminated, exterminated or eradicated.  It seems here to stay.

Defendants in the dock, International Military Tribunal (IMT, the main Nuremberg trial (1945-1946)). 

The meanings of eliminate, exterminate & eradicate, both in their English senses and in translation from German have been debated before.  Although not defined in law until the 1948 Convention on the Prevention and Punishment of the Crime of Genocide (CPPCG), the newly (1944) created word genocide appeared in the indictments served at the main Nuremberg trial (1945-1946) upon those accused under count IV, crimes against humanity.  This attracted the interest of lawyers who noted the words exterminate and eliminate appear both in the academic and legal discussions about the novel concept of genocide and in translations of many documents from the Third Reich which related to the Jews.  Defense counsel probed what was meant by these words and whether, in original or translation, their actual meaning in the context of their use was in accord with what was meant when applied to genocide.  The etymological excursion didn’t much help the defendants, most of whom were hanged.  Hermann Göring also raised an objection to a translation from the German being rendered as "final solution to the Jewish problem" rather than "total solution" which, he argued, should compel the court to draw a different inference.  In both discussions, the judges concluded what was being discussed was mass-murder and the relative degree of applicability between synonyms was not a substantive point.  Actually the word used by Göring in the first paragraph of the letter which ultimately authorized the holocaust was Gesamtloesung (complete solution) while in the final paragraph he use Endloesung (final solution).  This was the document which SS-Obergruppenführer (Lieutenant-General) Reinhard Heydrich (1904–1942; head of the Reich Security Main Office 1939-1942) revealed at the infamous Wannsee Conference (20 January 1942). 

Professionals in the field of pest control actually stick more closely to classic etymology in their technical distinction between the two central words: extermination and eradication.  Extermination (from the Latin, exterminare meaning “out of the boundary” and related to the deity Terminus who presided over boundaries) means to drive the pests beyond the boundaries of the building.  It doesn’t of necessity mean the pests are all dead, just that they are no longer in the building.  Eradicate (from the Latin eradicare meaning to root out) refers to the processes leading to extermination, to bring to light the breeding spots, the places where the infestation has, so to speak, taken root.

Dolichocephalic

Dolichocephalic (pronounced dol-i-koh-suh-fal-ik)

(1) The state of having a head much longer than it is broad, especially one with a cephalic index under 75.

(2) Any creature with such a head.

(3) A creature thought to have a disproportionately long head.

1852: The construct was dolicho + cephalic.  From New Latin dolichocephalus (long-headed) derived from the Greek dolichos (long) + kephalos (head); original form of kephalos was kephalē.  Used mostly in zoology and anthropology, forms include dolichocephaly (noun), hyperdolichocephalic  (adjective), hyperdolichocephaly (noun), subdolichocephalic (adjective), subdolichocephalism (noun), subdolichocephalous (adjective) and subdolichocephaly (noun).

Zoanthropic NFT: Lindsay Lohan's Furry canine (some suggested it was wolf-like) was rendered in dolichocephalic form.  The Lohanic fursona was first mentioned in September 2021 but not minted until October.

The cephalic index or cranial index is the ratio of the maximum width of the head of a creature multiplied by 100 divided by its maximum length.  The index is important to dog and cat breeders who seek mating pairs with an index number as close as possible to the defined ideal for a particular breed.  In general zoology, skull are classified into three types,  Those with ratios below seventy-five indicates skulls that are long and narrow, (dolichocephalic); those between seventy-five and eighty are slightly broader (mesocephalic); those with ratios above eighty are rounder (brachycephalic).

Armageddon

Armageddon (pronounced ahr-muh-ged-n)

(1) The place where the final battle will be fought between the forces of good and evil.

(2) The last and completely destructive battle; the scene of a decisive conflict on a great scale; any great and crucial conflict. 

(3) A catastrophic and extremely destructive conflict.

(4) In chess, as "armageddon round", an arrangement in some competitions used when a match would otherwise end in a draw, the rules being (1) black wins drawn games and (2) white is granted more time in compensation.

From the biblical Book of Revelation (New Testament 16:16) and the familiar modern use in the figurative sense of a final conflict apparently dates only from 1811.  The actual word was from the Late Latin Armagedōn, from the Ancient Greek Ἁρμαγεδών (Harmagedōn)), from the Hebrew הר מגידו or ‎הַר‎ מְגִדּוֹ‎ (har megiddo) (Mount of Megiddo), the mountain district of Megiddo, in northern Palestine, site of a number of battles mentioned in the Old Testament, most notably that associated with the Last Judgment.

The Last Judgment (circa 1488), triptych by Hieronymus Bosch (circa 1450–1516).

In the Book of Revelation, Armageddon is the prophesied location of a gathering of armies for a battle at the end of times.  Theologically, the western consensus is to interpret this as the battle between good and evil, often expressed as between God and the Kings on earth (Revelation, 16:14).  However, most biblical scholars regard the text as highly symbolic (even cryptic), regarding Mount Armageddon as an idealized location, concluding the final battle between good and evil, while inevitable, may well take place in some other location.  Others are more specific, a sect called the Dispensationalists suggests Armageddon will be a campaign (sometimes dramatically styled as the war of a thousand years) and not a specific battle.  All however agree it will be fought in and for the lands we call the Middle East.

Also disclosed in Revelation is the number of the Beast (Revelation 13:15–18).  In most English translations the number of the beast is 666 (although some early Greek translations prefer 616).

Then I saw another beast coming up out of the earth, and he had two horns like a lamb and spoke like a dragon. And he exercises all the authority of the first beast in his presence, and causes the earth and those who dwell in it to worship the first beast, whose deadly wound was healed.  He performs great signs, so that he even makes fire come down from heaven on the earth in the sight of men.

And he deceives those who dwell on the earth by those signs which he was granted to do in the sight of the beast, telling those who dwell on the earth to make an image to the beast who was wounded by the sword and lived.  He was granted power to give breath to the image of the beast, that the image of the beast should both speak and cause as many as would not worship the image of the beast to be killed.

He causes all, both small and great, rich and poor, free and slave, to receive a mark on their right hand or on their foreheads and that no one may buy or sell except one who has the mark or the name of the beast, or the number of his name.

Here is wisdom. Let him who has understanding calculate the number of the beast, for it is the number of a man: His number is 666.

The unfortunate condition Hexakosioihexekontahexaphobia is the fear of the number 666.  It's said to be rare.

Sarcophagus

Sarcophagus (pronounced sahr-kof-uh-guhs)

(1) A stone coffin, especially one bearing sculpture, inscriptions, etc, often displayed as a monument.

(2) In Ancient Greece, a kind of limestone thought to consume the flesh of corpses, used for coffins.

(3) In contemporary use, any (usually large) structure used to encase something.

(4) A form of wine cooler used in the eighteenth century.

1595-1605: From the French sarcophage, from the Latin sarcophagus, from the Ancient Greek σαρκοφάγος (sarkophágos) (coffin of limestone), noun use of the adjective sarcophagous.  The original in Ancient Greek was so named because of the limestone’s supposed property of consuming the flesh of corpses laid in it: σαρκοφάγος (sarkophágos) (flesh-eating, carnivorous), from the genitive σαρκός (sarkós) of σάρξ (sárx) (flesh; meat) + -φάγος (-phágos) (from ἔφαγον (éphagon), past of φάγω (phágō) (eat), the root of phagein (to eat) being the primitive Indo-European bhag- (to share out, apportion; to get a share).  The preferred plural remains sarcophagi although all dictionaries list the unpalatable sarcophaguses as an alternative.

In English, the sense "stone" was the earliest, the meaning "stone coffin, often with inscriptions or decorative carvings" didn’t emerge until 1705. The Classical Latin was shortened in Vulgar Latin to sarcus, source of the French cercueil (coffin, casket), the German Sarg (coffin) and the Dutch zerk (tombstone).  The reputation of lime as a means of causing the rapid putrefaction of corpses persisted well into the twentieth century and was the downfall of some murderers subsequently surprised to learn it acted instead as a preservative on the bodies they had buried.

The Chernobyl incident

Before incident

The incident at the Chernobyl power-plant on 26 April 1986 was trigged by an uncontrolled nuclear chain reaction which happened because of a series of events over two days, ironically during was supposed to be a test of safety systems.   After several explosions, during which quantities of radioactive material were released and spread widely over Europe, the core of reactor number four melted down.  Despite this, other reactors continued to operate and the Chernobyl power plant wasn’t finally decommissioned until December 2000.  The surrounding area is now an exclusion zone and will not be habitable for at least twenty-thousand years with the highly contaminated reactor number four encased in what was intended to be only a temporary concrete sarcophagus (the original Russian name was Объект Укрытие (Obyekt Ukrytiye) which translates as sheltering or covering); it’s since been covered with a metal enclosure.

After incident

The contaminated ruins of reactor number four were so dangerous that work on a sarcophagus began within a month of the meltdown, construction of the reinforced concrete structure substantially complete by November 1986.  However, the building had become so radioactive it became impossible for workers to approach close enough to finish the work and the robots used instead were not able completely to seal the sarcophagus.

Sarcophagus

Envisaged by engineers to have a life of thirty years, the sarcophagus deteriorated more quickly than had been expected and in 1997 an international project was formed to design and build something more durable.  Known as New Safe Confinement, it is a metal arch some 344 feet (105 metres) high and spanning 843 feet (257 metres), prefabricated and moved on rail lines, sliding over the existing sarcophagus.  The project team noted the adoption of the word confinement, rather than containment, commonly used in nuclear facility architecture.  The distinction is the difference between a reactor containment building which designed to contain radioactive gases and a structure built for the confinement of solid radioactive waste.

New Safe Confinement

Construction was completed in late 2018, after which trials and tests of the internal systems were run.  Unlike the sarcophagus, New Safe Confinement is designed to permit, using robotic devices, the remains of reactor number four safely to be dismantled and removed.  This is of course a man-made structure and like them all, nothing lasts forever and there is still no agreement between engineers about when a replacement layer will have to be added although all agree the new sarcophagus should adequately serve for decades; the discussion is about how many.

Nefarious

Nefarious (pronounced ni-fair-ee-uhs)

Extremely evil, wicked or villainous; iniquitous; sinful.

1595–1605: From the Latin nefārius (wicked, vile; execrable; abominable), the construct being nefās (something contrary to divine law, an impious deed, sin, crime) + -ius or –ious (the suffix from the Old Latin -ios, from the primitive Indo-European –yós and used to form adjectives from nouns.  The Middle English suffix –ous was borrowed from the Old French -ous & -eux, from the Latin -ōsus (full, full of); a doublet of -ose in the unstressed position).  The construct of nefās was ne- (the negative prefix) + fās (law, right).  Nefarious is an adjective, nefariously is an adverb and nefariousness is a noun.

Crooked Hillary Clinton & Harvey Weinstein, Lincoln Centre, New York, April 2012.

Neophyte

Neophyte (pronounced nee-uh-fahyt)

(1) A beginner or novice at something;  person who is new to a subject, skill, or belief.

(2) In the Roman Catholic Church, a novice in a religious order; a new convert or proselyte; a new monk.

(3) A person newly converted to a belief, as a heathen, heretic, or nonbeliever; proselyte.

(4) In Christianity, a name given by the early Christians (and still by the Roman Catholics), to those who have recently embraced the Christian faith, and been admitted to baptism, especially those converts from heathenism or Judaism (in most of the primitive Church, a person newly baptized).

(5) In botany, a plant species recently introduced to an area (in contrast to archaeophyte, a long-established introduced species).

1550-1460:  From the Ecclesiastical Latin neophytus (newly planted), from the Ancient Greek νεόφυτος (neóphutos) (newly planted), the construct of which was νέος (néos) (new) + φυτόν (phutón) (plant, child), the origin of which was a verbal adjective of phyein (cause to grow, beget, plant).  In the Greek used in the New Testament, the spelling was neophutos.  Neophyte is a noun & adjective, neophytic & neophytish are adjectives and neophytism is a noun; the noun plural is neophytes.

Churches and cults

In both the biblical sense of "a young scholar" and the general sense of "someone new to something", Cady Heron in Mean Girls (2004) was a neophyte.

Despite the lineage, use in English was rare prior to the nineteenth century.  The technical sense of ecclesiastical use is from I Timothy iii:6 and the general sense of "one who is new to any subject" was first recorded in the 1590s.  In early translations of the Bible, the neophyte was “a young scholar”, the implication being an “old scholar” could not be a neophyte by deferring his baptism or by long delaying his conversion to God which he had long before learned to be necessary.  As Christianity became increasingly corporatized in the search for bums on pews, view became less rigorous.  The word is also a favorite among cults.  In the symbolism of Freemasonry, the north refers to the outer or profane world and the east the inner world of Masonry; hence the cornerstones of Masonic Lodges are laid always in the south-east corner and the initiations of neophytes is always undertaken with them facing the north-east, symbolic of the position of neophytes, partly in the darkness of the former, partly in the light of the latter.

Cornerstone of a Masonic Lodge.

One of history's better known Masonic plots involves the White House's missing its cornerstone.  In October 1792, a group of freemasons assembled at a Georgetown tavern and paraded to the proposed site of the president’s mansion where they conducted certain rituals.  In one ceremony, they placed an inscribed cornerstone and then repaired to the inn to toast the event.  According to Masonic legend, some sixteen toasts were made, one consequence of which was they neglected to document the cornerstone's location.  Subsequent searches never located the stone and even when the White House underwent extensive renovations between 1948-1952 (engineers in 1948 threatened to condemn the building such was the state of structural decay) it wasn't discovered.  The post popular theory is it sits embedded between two stone walls near the Rose Garden.

Photon

Photon (pronounced foh-ton)

The subatomic particle that carries the electromagnetic force and is the quantum of electromagnetic radiation; has a rest mass of zero, but has measurable momentum, exhibits deflection by a gravitational field, and can exert a force.  It has no electric charge, has an indefinitely long lifetime, and is its own antiparticle.  It is the quantum (a bundle of energy) in which light and other forms of electromagnetic radiation are emitted.

1916: A compound word phot(o)- +‎ -on.  Photo is from the Ancient Greek combining form φωτω- (phōtō-) from φῶς (phôs) (light).  The –on suffix is used often in science, in physics (eg electron) and in chemistry (eg carbon) and is from the Ancient Greek -ον (-on), used when ending neuter nouns and adjectives.  In physics, mathematics and biology, it forms nouns denoting subatomic particles (proton), quanta (photon), molecular units (codon), or substances (interferon).  In biology and genetics, it’s applied to form names of stuff considered basic or fundamental units such as codon.  In chemistry, it’s used to form names of noble gases and certain nonmetal elements such as boron or silicon.  Photon was coined in 1916 by US physicist Leonard Troland (1889-1932) as a unit of light hitting the retina but the word was little used until the 1920s when a number of scientific papers were published.  Although the findings of some of the early experiments were later disproved, the word was soon adopted by most physicists.  Photon is a noun and photonic an adjective; the noun plural is photons.  

The light quantum

The photon is also called the light quantum.  The Latin word quanta (how much; the singular form is quantum) was used in the nineteenth century to mean particles or as a measure of quantity, the latter meaning persisting in general use.  What light was actually made from was, until the early twentieth century, one of the fundamental arguments in physics; the dispute essentially whether light was a wave or a particle.  Albert Einstein (1879-1955) published his theory in a 1905 paper which described electromagnetic waves as “…spatially localized, discrete wave-packets” which he labeled das lichtquant (the light quantum).  Light has special characteristics: apart from being creation’s universal speed limit, photons have a unique property in that they are both a particle and a wave, almost certainly have no mass and carry no charge.

JPL (NASA's Jet Propulsion Laboratory) used the properties of the photon to illustrate the weird world of quantum theory.

Photons underlie Einstein’s theory of relativity.  Travelling at the speed of light (and light can be slowed-down or stopped), if a photon could visualize, the entire universe would appear as a two-dimensional timeless plane which is completely still.  However, a photon can’t visualize or even experience anything because, for a proton, time doesn't pass, physicists labeling such things null geodesics.  A photon moves from its start to its end: An interaction creates (or emits) it until another interaction destroys (or absorbs) it.  These two things, creation and destruction, are all that can happen to a photon and neither can be experienced because there’s no time; what photons do can be measured but the frame of reference is wholly external.  In an inertial reference frame, there are physical laws which don't depend on the motion of anything external to the system yet for a photon, the physical rules it obeys depend exclusively on everything which happens external to it.

Weirder still, because protons lack mass, a photon cannot visualize the rest of the universe because seeing requires interacting with other particles, antiparticles, or photons, and, once such an interaction occurs, that photon's journey is over, its destruction as instantaneous as its creation.  Thus the fundamental importance of time to the existence of three-dimensional space; were there no time, everything would happen at once.

Neutrino

Neutrino (pronounced noo-tree-noh, nyoo-tree-noh)

In physics, a stable elementary particle, classified as a lepton which has an extremely small (but nonzero) mass and no electric charge. Travelling at the speed of light, it interacts with the surroundings only via the weak force or gravitation, making it very difficult to detect.  Three types exist, associated with the electron, the muon, and the tau particle.  The neutrino symbol is a V.

1932: Coined by Italian physicist Enrico Fermi (1901-1954), the construct being neutr(on) + -ino.  Neutron was a formation of neutral +‎ -on (the suffix forming nouns denoting subatomic particles (proton), quanta (photon), molecular units (codon), or substances (interferon).  It was coined by Scottish-Australian physicist William Sutherland in 1899 in a paper in the Philosophical Magazine. Subsequent usage was sporadic and theoretical, sometimes referring to neutrinos rather than neutrons, and the modern sense was reintroduced by New Zealand physicist Ernest Rutherford (1871-1937) in 1920.  The Italian diminutive suffix –ino (plural -ini, feminine -ina) is from the Latin -īnus, from the primitive Indo-European –iHnos (and is most comparable with the English suffix –ine).  It’s (1) an alterative suffix used to form diminutives, (2) a derivational suffix used to form adjectives or nouns, (3) used to indicate an ethnic or geographical origin, (4) used to indicate tools or instruments and (5) used to derive adjectives denoting composition, colour or other qualities.  In Italian, neutrino means “little neutron”.  Neutrino is a noun; the noun plural is neutrinos 

They're everywhere

Although not observed until 1955, Austrian-Swiss physicist Wolfgang Ernst Pauli (1900-1958) created a theoretical model in 1930 of what he called the neutron, the word modelled on electron.  He speculated his new particle was emitted from the nucleus together with the electron or beta particle in the process of decay.  The word neutrino entered the scientific lexicon after Italian–American physicist Enrico Fermi used it at a Paris conference in 1932.  Neutrinos are among the most abundant particles in the universe, billions of which produced by nuclear reactions in the sun pass through every human body on earth every second without disturbing any atoms.  An incalculable number were created fractions of a second after the Big Bang and new ones are constantly being generated, in the nuclear hearts of stars, in particle accelerators and atomic reactors on Earth, during the explosive collapse of supernovas and when radioactive elements decay. Physicists estimate, at any given point in time or space, there are a billion times more neutrinos than protons in the universe.

A perfect gift for nerds, neutrino T-shirts are available in designer colors. 

Despite their ubiquity, neutrinos remain mysterious, streaming through most matter as if they were light rays going through a transparent window, scarcely interacting with everything else in existence.  They made the headlines in 2011 when researchers in Italy suggested they had detected neutrinos traveling faster than the speed of light, hitherto thought impossible.  Technical faults in the measurement were later detected and neutrinos resumed their place as cosmically law-abiding particles.  Later reports from the US indicate the possibility a fourth type (the so-called sterile neutrino) might exist; if detected, known laws of physics would have to be amended because sterile neutrinos don't fit into what's known as the Standard Model, a framework that explains almost all known particles and forces except gravity.  A new analytical framework would be required.

Parsec

Parsec (pronounced pahr-sek)

A unit of astronomical length, based on the distance from Earth at which a star would have a parallax of one second of arc which is equivalent to 206,265 times the distance from the earth to the sun or 3.26 light-years.  Its lineal equivalent is about 19.1 trillion miles (30.8 trillion km).

1913: The construct was par + sec, derived from parallax + second.  Parallax is from the Middle French parallaxe, from the Ancient Greek παράλλαξις (parállaxis) (alteration) from παραλλάσσω (parallássō) (to cause to alternate) from ἀλλάσσω (allássō) (to alter) from ἄλλος (állos) (other).  Second, in the sense of time, is from the Middle English secunde & seconde, borrowed from the Old French seconde, from the Medieval Latin secunda, short for secunda pars minuta (second diminished part (of the hour)). Parsec is a noun; the noun plural is parsecs.

Distance in space

The parsec (pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System.  A parsec is defined as the distance at which one astronomical unit subtends an angle of one arc second, which corresponds to 648000 astronomical units.  The nearest star to Earth, Proxima Centauri, is about 1.3 parsecs (4.2 light-years) from the Sun.

The parsec unit appears first to have been suggested in 1913 by the English astronomer Professor Herbert Hall Turner (1861-1930).  It was invented to permit calculations of astronomical distances using only raw observational data and is thus the default unit of measure in astronomy and astrophysics although the more-easily understood light-year is preferred by lay-persons.  While useful to describe the comparatively short distances within the Milky Way, multiples of parsecs are needed to map the wider universe including kiloparsecs (kpc) for objects immediately beyond the Milky Way and megaparsecs (Mpc) for more distant galaxies.  Gigaparsecs (Gpc) are used to measure the quasars and galaxies which exist at the extreme edge of the known universe; the particle horizon (the boundary of the observable universe) has a radius of about 14.0 Gpc (46 billion light-years).

Although in use for more than a century, the parsec wasn’t formally defined until August 2015 when the International Astronomical Union (IAU) which, as part of the definition of a standardized absolute and apparent bolometric magnitude scale, noted the existing explicit definition of the parsec as exactly 648000 astronomical units, or approximately 3.08567758149137×10¹⁶ metres.

Hubble telescope image of star-forming region in the Carina Nebula.  As photographed, the gas and dust cluster is about .889 of a parsec (2.9 light-years) tall.

Stratosphere

Stratosphere (pronounced strat-uh-sfeer)

(1) The region of the upper atmosphere extending between the tropopause and mesosphere to about 30 miles (50 kilometers) above the earth, characterized by little vertical change in temperature.

(2) In historic documents, all of the earth's atmosphere lying outside the troposphere (obsolete).

(3) Any great height or degree of anything, as the highest point of a graded scale.

(4) In geology, collectively, those layers of the Earth’s crust which primarily comprise stratified deposits (obsolete).

1908: From the French stratosphère, the construct being strato + sphère (literally "sphere of layers").  It was coined by French meteorologist Léon-Philippe Teisserenc de Bort (1855-1913).  Strato was an inflected form of strātus (a spreading out), the perfect passive participle of sternō (spread) and past participle stem of sternere (to spread out) from the primitive Indo-European root stere- (to spread).  Sphere was from the Middle English spere, from the Old French sphere, from the Medieval Latin sphēra, from the Classical Latin sphaera (ball, globe, celestial sphere), from the Ancient Greek σφαῖρα (sphaîra) (ball, globe) of unknown origin and despite the apparent similarity, not related to the Persian سپهر‎ (sepehr) (sky).  The earlier use of the word, attested in English 1908 and coined in German 1901, was a geological term for part of the Earth's crust and has long been wholly obsolete.  The second major layer of Earth's atmosphere, the stratosphere sits above the troposphere and below the mesosphere.  Itself stratified, the stratosphere’s cooler layers are closest to the Earth’s surface, the higher layers warmed by the absorption of the Sun's ultraviolet radiation in the ozone layer, a reversal of the process in the troposphere where temperature decreases with altitude.  Stratosphere is a noun, and stratospheric & stratospherical are adjectives; the noun plural is stratospheres.

Layers

It was once thought the first living things to enter the stratosphere were some fruit flies, sent there by the US Air Force aboard one of the V-2 rockets seized from the German's wartime missile programme.  Launched in February 1947 from the White Sands Missile Range in New Mexico, the purpose of the flight was to explore the effects of radiation exposure at these then novel high altitudes; the V2 attained a height of 68 miles (109 kilometres) and all fruit flies survived the trip.  It was soon appreciated however that some bacteria or viruses must have been present in or on the V2s launched by the Germans between 1944-1945 and many of these would, at least briefly, have entered the stratosphere but even these appear not to have been the first living (and viruses are in some sense “alive”) things there.

Although the tropopause (the uppermost layer of the troposphere) is thought a barrier to the upward movement of particles, volcanoes are an obvious means by which this could occur although such eruptions are rare.  Bacterial life does however survive in the stratosphere, making it technically, part of the biosphere and, in 2001, dust was collected at a height of 25 miles (41 kilometres) which, upon analysis, was found to contain bacteria of surprisingly large size.  The discovery excited speculation that such large bacterial masses may be incoming to Earth, the suggestion being that (1) the bacteria may have arrived in the stratosphere from space and (2) the possibility that the transfer of bacteria from the Earth to the highly mutagenic stratosphere may have played a role in bacterial evolution.  Among the scientific community, enthusiasm for these theories was restrained.