Concord & Concorde

Concord or Concorde (pronounced kon-kawrd)

(1) Agreement between persons, groups, nations, etc.; concurrence in attitudes, feelings, etc; unanimity; accord; agreement between things; mutual fitness; harmony.

(2) In formal grammar, a technical rule about the agreement of words with one another (case, gender, number or person).

(3) A treaty; compact; covenant.

(4) In music, a stable, harmonious combination of tones; a chord requiring no resolution.

(5) As concordat, under Roman-Catholic canon law, a convention between the Holy See and a sovereign state that defines the relationship between the Church and the state in matters that concern both.

(6) In law, an agreement between the parties regarding land title in reference to the manner in which it should pass, being an acknowledgment that the land in question belonged to the complainant (obsolete).

(7) A popular name for locality, commercial operations and products such as ships, cars etc.

(8) In horticulture, a variety of sweet American grape, named circa 1853 after Concord, Massachusetts, where the variety was developed.

1250-1300: From the Middle English and twelfth century Old French concorde (harmony, agreement, treaty) & concorder, from the Latin concordare & concordia, (harmonious), from concors (of the same mine; being in agreement with) (genitive concordis (of the same mind, literally “hearts together”)).  The construct was an assimilated form of com (con-) (with; together) + cor (genitive cordis (heart) from the primitive Indo-European root kerd (heart)).  The "a compact or agreement" in the sense of something formal (usually in writing) dates from the late fifteenth century, an extension of use from the late fourteenth century transitive verb which carried the sense "reconcile, bring into harmony".  From circa 1400 it had been understood to mean "agree, cooperate, thus a transfer of sense from the Old French & Latin forms.  Concorde was the French spelling which eventually was adopted also by the British for the supersonic airliner after some years of linguistic squabble.  Concord is a noun & verb, concordance & concordat are nouns, concorded & concording are verbs and concordial & concordant are adjectives; the noun plural is concords.

The Concorde and other SSTs

Promotional rendering of Concorde in British Overseas Airways Corporation (BOAC) livery.  BOAC was the UK's national carrier between 1940-1974 when merged with British European Airways (BEA) to form British Airways (BA).

Concorde was an Anglo-French supersonic airliner that first flew in 1969 and operated commercially between 1976-2003.  It had a maximum speed over twice the speed of sound (Mach 2.04; 1,354 mph (2,180 km/h)) and seated 92-128 passengers.  Man breaking the sound barrier actually wasn’t modern; the cracking of a whip, known for thousands of years, is the tip passing through the sound barrier and engineers were well aware of the problems caused by propellers travelling that fast but it wasn’t until 1947 that a manned aircraft exceeded Mach 1 in controlled flight (although it had been achieved in deep dives though not without structural damage).  The military were of course immediately interested but so were those who built commercial airliners, intrigued at the notion of transporting passengers at supersonic speed, effectively shrinking the planet.  By the late 1950s, still recovering from the damage and costs of two world wars, France and the UK were never going to be in a position to be major players in the space-race which would play-out between the US and USSR but civil aviation did offer possibilities for both nations to return to the forefront of the industry.  France, in the early days of flight had been the preeminent power (a legacy of that being words like fuselage and aileron) and UK almost gained an early lead in passenger jets but the debacle of the de Havilland Comet (1949) had seen the Boeing 707 (1957) assume dominance.  The supersonic race was thought to be the next horizon and the UK’s Supersonic Transport Aircraft Committee (STAC) was in 1956 commissioned with the development of a Supersonic Transport (SST) for commercial use.

Concordes exist in a number of flight simulator programs; this is Colimata's Concorde v1.10 in BA livery.

The committee’s early research soon established it was going to be an expensive undertaking so the UK sought partners; the US declined but in 1962 the UK and France signed the Anglo-French Concorde agreement, a framework for cooperation in the building of the one SST.  The choice of name actually came some months after the engineering concord was signed, the manufacturers submitting to the UK cabinet the names Concord and Concorde, it being thought desirable to have something which sounded and meant the same in both languages (the French had already agreed it shouldn’t be called the Super-Caravelle the project name for a smaller SST on which some work had been done in 1960).  The other suggestions put to cabinet were Alliance or Europa.  In the cabinet discussions in London, Alliance was thought to be "too military" and Europa offended those Tories who still hankered for the "splendid isolation" which had been the British view on European matters in the previous century.  Even in the nineteenth century age of Pax Britannica splendid isolation had been somewhat illusory but in the Tory Party the words still exerted a powerful pull.  

The French-built Concorde 001's roll-out, Toulouse Blagnac airport, 11 December 1967.

There is some dispute about whether the cabinet ever formally agreed to use the French spelling but, like much in English-French relations over the centuries, the entente proved not always cordial and the name was officially changed to Concord by UK Prime Minister Harold Macmillan (later First Earl Stockton, 1894–1986; UK prime-minister 1957-1963) in response to him feeling slighted by Charles de Gaulle (1890-1970; President of France 1958-1969) when Le President vetoed the UK’s application to join the European Economic Community (the EEC which evolved into the present Day EU of which the UK was a member between 1973-2020).  However, the Labour party won office in the 1964 general election and by the time of the roll-out in Toulouse in 1967, the UK’s Minister for Technology, Tony Benn (Anthony Wedgwood Benn, 1925–2014, formerly the second Viscount Stansgate) announced he was changing the spelling back to Concorde.  There were not many eurosceptics in the (old) Labour Party back then.

Concorde taking off, 1973 Paris Air Show, the doomed Tupolev Tu-144 in the foreground.

The engineering challenges were overcome and in 1969, some months before the moon landing, Concorde made its maiden flight and, in 1973, a successful demonstration flight was performed at the same Paris air show at which its Soviet competitor Tupolev Tu-144 crashed.  Impressed, more than a dozen airlines placed orders but within months of the Paris show, the first oil shock hit and the world entered a severe recession; the long post-war boom was over.  A quadrupling in the oil price was quite a blow for a machine which burned 20% more fuel per mile than a Boeing 747 yet typically carried only a hundred passengers whereas the Jumbo could be configured for between four and five hundred.  That might still have been viable had have oil prices remained low and a mass-market existed of people willing to pay a premium but with jet fuel suddenly expensive and the world in recession, doubts existed and most orders were immediately cancelled.

Concorde 002 on public display at BAC's (British Aircraft Corporation) airfield, Filton, Bristol, site of its construction.

Eventually, only twenty were built, operated only by BOAC (BEA/BA) and Air France, early hopes of mass-production never materialized; while orders were taken for over a hundred with dozens more optioned, the contracts were soon cancelled.  By 1976 only four nations remained as prospective buyers: Britain, France, China, and Iran; the latter two never took up their orders and by the time Concorde entered service, the US had cancelled their supersonic project and the Soviet programme was soon to follow.  Even without the oil shocks of the 1970s and the more compelling economics of wide-bodied airliners like the Boeing 747, there were problems, the noise of the sonic boom as the speed of sound was exceeded meaning it was impossible to secure agreement for it to operate over land at supersonic speed.  Accordingly, most of its time was spent overflying the Atlantic and Pacific and BA and Air France sometimes made profit from Concorde only because the British and French governments wrote off the development costs.  Concorde was an extraordinary technical achievement but existed only because the post-war years in the UK and France were characterised by national projects undertaken by nationalised industries.  Under orthodox modern (post Reagan cum Thatcher) economics, such a thing could never happen. 

Concorde F-BTSC (Air France Flight 4590), Charles de Gaulle Airport, Paris, France, 25 July 2000.

On 25 July 2000, Air France Flight 4590, bound for New York, crashed on take-off out of Paris, killing all 109 on board and a further four on the ground. It was the only fatal accident involving Concorde, the cause determined to be debris on the runway which entered an engine, causing catastrophic damage.  In April 2003, both Air France and British Airways announced that they would retire Concorde later that year citing low passenger numbers following the crash, the slump in air travel following the 9/11 attacks and rising maintenance costs.

Lindsay Lohan in The Parent Trap (1998)

Fictional works are usually constructed cognizant of physical reality and technological innovations have always influenced what's possible in plot-lines.  The cell phone for example offered many possibilities but also rendered some situations either impossible or improbable (although Hollywood has sometimes found either of those no obstacle in a screenplay).  The retirement of Concorde also had to be noted.  Not only had it long been used as a symbol of wealth but there was also the speed so plot-lines which included the relativities of the duration of commercial supersonic versus subsonic trans-Atlantic travel were suddenly no loner possible.  Lindsay Lohan's line in The Parent Trap (1998) since 2003 (and for the foreseeable future) is a "stranded relic" of the Concorde era.     

Tupolev Tu-144 (NATO reporting name: Charger).

The Tu-144 was the USSR’s SST and it was the first to fly, its maiden flight in 1968 some months before Concorde and sixteen were built.  It was also usually ahead of the Anglo-French development, attaining supersonic speed twelve weeks earlier and entering commercial service in 1975 but safety and reliability concerns doomed the project and its reputation never recovered from the 1973 crash.  The Soviet carrier Aeroflot introduced a regular Moscow-Almaty service but only a few dozen flights were ever completed, the Tu-144 withdrawn after a second crash in 1978 after which it was used only for cargo until 1983 when the remaining fleet was grounded.  It was later used to train Soviet cosmonauts and had a curious post-cold war career when chartered by NASA for high-altitude research.  The final flight was in 1999.

Boeing 2707.

While perfecting supersonic military aircraft during the early 1950s, Americans had explored the idea of SSTs as passenger aircraft and had concluded that while it was technically possible, in economic terms such a thing could never be made to work and that four-engined jets like the Boeing 707 and Douglas DC8 were the future of commercial aviation.  However, the announcement of the development of Concorde and the Soviet SST stirred the Kennedy White House into funding what was essentially a vanity project proving the technical superiority of US science and engineering.  Boeing won the competition to design an SST and, despite also working on the 747 and the space programme, it gained a high priority and the 2707 was projected to be the biggest, fastest and most advanced of all the SSTs, seating up to three-hundred, cruising at Mach 3 and configured with a swing-wing.  Cost, complexity and weight doomed that last feature and the design was revised to use a conventional delta shape.  But, however advanced US engineering and science might have been, US accountancy was better still and what was clearly an financially unviable programme was in 1971 cancelled even before the two prototypes had been completed.

Lockheed L-2000.

Lockheed also entered the government-funded competition to design a US SST.  Similar to the Boeing concept in size, speed and duration, it eschewed the swing-wing because, despite the aerodynamic advantages, the engineers concluded what Boeing would eventually admit: that the weight, cost and complexity acceptable in military airframes, couldn’t be justified in a civilian aircraft.  As the military-industrial complex well knew, the Pentagon was always more sanguine about spending other people's money (OPM) than those people were about parting with their own.  Lockheed instead used a slightly different compromise: the compound delta.  After the competition, Boeing and Lockheed were both selected to continue to the prototype stage but in 1966 Boeing’s swing-wing design was preferred because its performance was in most aspects superior and it was quieter; that it was going to be more expensive to produce wasn’t enough to sway the government, things being different in the 1960s.  Reality finally bit in 1971.

Depiction of a Boom Overture in United Airlines livery.

In mid-2021 US carrier United Airlines (UA) announced plans to acquire a fleet of fifteen new supersonic airliners which they expected to be in service by 2029.  It wasn’t clear from the press release what was the most ambitious aspect of the programme: (1) that Colorado-based Boom (which at the time had not achieved supersonic flight), would be able by 2029 to produce even one machine certified by regulatory authorities for use in commercial aviation, (2) that the aircraft would be delivered at close to the budgeted US$200 million unit cost, (3) that what United describe as “improvements in aircraft design since Concorde” will eliminate, reduce or mitigate (all three have at various times been suggested) the effects of the sonic boom, (4) that it won’t be “any louder than other modern passenger jets while taking off, flying over land and landing”, (5) that sufficient passengers will be prepared to pay a premium to fly at Mach 1.7 in a new and unproven airframe built by a company with no record in the industry or that (6) Greta Thunberg (b 2003) will believe Boom which says Overture will operate as a "net-zero carbon aircraft".

Looking sceptical: Greta Thunberg.

The suggestion was the Overture will run on "posh biodiesel", made from anything from waste cooking fat to specially grown high-energy crops although whether this industry can by 2029 be scaled-up to produce what will be required to service enough of the aviation industry to make either project viable isn’t known.  Still, if not, Boom claimed "power-to-liquid" processes by which renewable energy such as solar or wind power is used to produce liquid fuel will make up any shortfall.  Boom does seem a heroic operation: they expect the Overture to be profitable for airlines even if tickets are sold for the same price as a standard business-class ticket.  One way or another, the flight-path (figuratively and literally) of the Boom Overture follows is going to become a standard case-study in university departments although whether that's in marketing, engineering or accountancy might depend matters beyond Boom's control.

Boom XB-1 in subsonic flight.

Boom’s progress can’t however be denied because on 10 February, 2025, its XB-1 “proof of concept” test platform accomplished what orthodox physics once deemed impossible.  On that day if flew over California’s Mojave Desert at speeds beyond the sound barrier without generating a sonic boom, the announcement surprising some sceptics but doing little to quell the doubts among analysts unable to build models which show a sustained profitable life for the project.  What Boom did with the XB-1 was use an implementation of “Mach cut-off” technology which exploits atmospheric conditions by manipulation, redirecting shock waves upward rather than toward the ground.  This is achieved by operating the airframe in a certain four-dimensional envelope (a window created by specific atmospheric conditions within a certain height range up to a certain speed).  Flying within these parameters, the airframe minimizes the unwanted effects of pressure waves, dispersing them without forming the concentrated pressure front that creates the dreaded sonic booms.  Whatever the sceptical economic modelers may conclude, it was an impressive display of Boom’s technology and engineering with the ground-level impact eliminated, at least in the ideal, controlled conditions of a test flight.

Scripps Climate Physics explains Mach Cut-Off.

What the economists noted was the XB-1 was able to achieve the much vaunted “silent-supersonic” at around 1,200 km/h (750 mph) and the math indicates the means to implement Mach cut-off when travelling faster (certainly the 2,100 km/h (1300 mph; Mach 1.7) which apparently remains Boom’s target) doesn’t yet exist, even at the level of theory.  On land, sea or air, for centuries what has determined commercial viability is the speed-cost trade-off and notional profitability was for at least some of Concorde’s years of operation achieved because it offered a quicker trans-Atlantic flight-time (typically the Concorde at Mach 2.04 (1,350 mph, 2,180 km/h) would take 3 hours 30 minutes while at Mach 0.85 (565 mph, 910 km/h), a Boeing 747 would need 7-8 hours).  In truth that profitability was a fudge subsidized by taxpayers (a remarkably common phenomenon in modern capitalism) because the French & British governments “wrote off” the development costs (some Stg £1.3 billion by the late 1970s at a time when a billion pounds was still a lot of money and even that may have been a deliberate under-estimate to conceal the true cost which has been estimated (in 2023 Sterling value terms) as high as Stg£21 billion).

Boom XB-1 taking off.

Rich customers or those with tickets paid for by OPM (other people’s money) were prepared to pay the significant premium charged for a seat on Concorde just to avoid sitting an additional 4-5 hours on a wide-bodied subsonic aircraft and that’s the market Boom is interested in for a trans-continental (New York City (NYC) to Los Angeles (LA)) US service.  Subsonic flight times on the NYC-LA route are typically 5-6 hours while Boom will be able to achieve that in under two hours if their silent subsonic plans can be realized; that would mean the road transport components of a trip elements to and from the NYC & LA airports could be longer than the time in the air.  If able to offer a 3-4 hour reduction in NYC-LA travel time, genuinely that’s a marketing advantage but one which can be leveraged only if there are enough customers willing (with the required frequency) to spend somebody’s money to fill the seats of UA’s 15 silentsonics.  If, as Boom once indicated to venture capitalists (VC) and others (JAL (Japan Airlines has reportedly invested US$10 million), the tickets on the NYC-LA route would retail at around the subsonic business-class level, then few doubt their model will work but it remains to be seen whether what’s necessary can be achieved (1) by 2029 or (2) ever.  Hopefully, Boom does succeed so delta-winged supersonics can make a (quieter) return to the skies though it’ll be a shame if the marketing department insisted on changing the corporate name to something like “Boomless”, “No Boom”, “Boom-Free” or whatever.  “Boom” is a really good name for an aviation outfit has some history in the field, “Boom” the nickname of Marshal of the Royal Air Force Hugh Trenchard (First Viscount Trenchard, 1873–1956) who was instrumental in the formation of Britain’s RAF (Royal Air Force) although he gained the moniker because of the tone of his voice rather than anything to do with fluid dynamics.

Snoot

Snoot (pronounced snoot)

(1) In slang, the nose (of humans, animals, geological formations, distant galaxies and anything else with a feature even vaguely “nose-like”).

(2) In slang, an alcoholic drink.

(3) In slang, a police officer (especially a plain-clothed detective, the use explained by the notion of police “sticking their noses into” things).

(4) In clothing, the peak of a cap.

(5) In photography and film production, a cylindrical or conical e-shaped fitment on a studio light to control the scene area illuminated by restricting spill light.

(6) In informal use, a snob; an elitist individual; one who looks down upon those “not of the better classes”.

(7) In linguistics, a language pedant or snob; one who practices linguistic elitism (and distinct from a “grammar Nazi”).

(8) In engineering, as “droop snoot”, a design in which the nose of a machine is lowered (temporarily or permanently) for reasons of visibility or to optimize aerodynamics.

(9) To behave disdainfully toward; to condescend to (usually as “snooty”).

(10) To apply a snoot attachment to a light.

1861: From the Scots snoot (a variation of snout (nose or projecting feature of an animal), from the Middle English snowte, from the Middle Dutch snute, ultimately from the Proto-West Germanic snūt, from the Proto-Germanic snūtaz, source also of the German Schnauze (the basis of schnauzer, a name for a type of dog) and it’s presumed the slang schnoz (a nose, especially if large) is probably related.  Snoot is a noun & verb, snootiness, snooter & snootful are nouns, snooting & snooted are verbs, snooty, snootier & snootiest are adjectives and snootily is an adverb; the noun plural is snoots.

Lindsay Lohan's snoot.

The noun snootful dates from 1885 and was a synonym of skinful (to have imbibed as much liquor as one could manage).  It was based on the use of snout to mean “an an alcoholic drink” whereas skinful was an allusion to the time when wine was transported in containers made from animal skin (ie in original use skinful meant “the container is full”).  The adjective snooty (proud, arrogant) was first noted as university student slang in 1918 and presumably was in some way related to the earlier snouty (insolent, overbearing) which was in use by at least 1857, doubtlessly on the basis of “looking down one's nose at someone or something”.  In dialectal or slang use a snout (in the sense of “nose” is not of necessity derogatory and in fields like engineering, cosmology, geography, geology, cosmology or zoology, it is merely descriptive.  However, when used as a slang term for a snob (a snooty person), the sense is almost always negative although there are some elitists who are proud of their snootiness.  Those who don’t approve of barbarisms such as country & western music sometimes make sure their snootiness is obvious but as a general principle it’s usually better just to ignore such things.  The adjective snooty is in much more common use than the noun snoot and it appears often with a modifier such as “a bit snooty”.  That may seem strange because one is either snooty about someone or something or one isn’t but there are degrees of severity with which one can allow ones snootiness to manifest (the comparative “snootier”, the superlative “snootiest”.

In engineering, “droop snout” is used to describe a design in which the nose of a machine is lowered (temporarily or permanently) for reasons of visibility or to optimize aerodynamics.  The term was apparently first used between engineers in the late 1950s while working on the first conceptual plans for the Anglo-French supersonic airliner which became the Concorde although the first known use in print dates from 1963 (“droop nose” appearing in the same era).  The idea wasn’t developed for use on the Concorde.  An experimental British supersonic test-bed with a droop-nose had flown as early 1954 and proved the utility of the concept by being the first jet aircraft to exceed 1000 mph (1600 km/h) in level flight, later raising the world speed record of to 1132 mph (1822 km/h), exceeding the previous mark by an impressive 310 mph (500 km/h).  In aviation, the basic idea of a sloping nose had been around for decades and one of the reasons some World War II (1939-1945) Allied fighter pilots found targeting easier in the Hawker Hurricane than the Supermarine Spitfire was the nose of the former noticeably tapered towards the front, greatly enhancing forward visibility.

How the Concorde's droop snoot was used.

On the Concorde, the droop snoot wasn’t a mere convenience.  The combination of the engineers slide-rules and wind tunnel testing had proved what the shape had to be to achieve the combination of speed and fuel economy (the latter an under-estimated aspect of the development process) but that shape also meant the pilots’ view was so obstructed during take-offs, landings and taxiing that safety was compromised.  The solution was the “droop nose” mechanism which included a moving transparent visor which retracted into the nose prior to being lowered.  At supersonic speeds, the temperatures are high and so are the stresses so much attention was devoted to “fail-safe” systems including the droop snoot because a structural failure at Mach 2 would potentially be catastrophic for the entire airframe (and obviously every soul on board).  Thus, the hydraulic systems controling the droop snoot’s movement was duplicated and, as a last resort, the pilots had access to a simple mechanical lever which would disengage the pins holding the structure in place, the apparatus afterwards gracefully (hopefully) descending into its lowered position by the simple operation of gravity.  Droop snoots appeared also on Soviet supersonic aircraft including the short-lived Tupolev Tu-144 (visually close to a Concorde clone) and the Sukhoi T-4 strategic bomber which never entered production.  Interestingly, the USAF’s (US Air Force) North American XB-70 Valkyrie (a Mach 3 experimental bomber) didn’t use a droop snoot because it was developed exclusively for high-altitude, high-speed strategic bombing missions and, being a military airplane, would only ever operate from large, controlled airbases where additional ground support systems (monitoring and guidance) negated the need for the mechanism.

1955 Ford Customline (left) and the 1967 “droop snoot” “Custaxie” (right), the construct being Cust(omline) + (Gal)axie, the unusual hybrid created by merging (some of) a 1955 Customline with a 427 cubic inch (7.0 litre) Ford Galaxie V8.  The bizarre machine won the 1967 New Zealand Allcomers (a wonderful concept) saloon car championship, the modifications to the nose reckoned to be the equivalent of an additional 40-50 horsepower.

At sub-supersonic speeds, throughout the 1960s race-cars proved the virtue of the droop snoot (though a fixed rather than a moveable structure.  While sometimes weight-reduction was also attained, overwhelmingly the advantage was in aerodynamics and the idea began to spread to road cars although it would be decades before the concept would no longer be visually too radical for general market acceptance.

1972 Vauxhall Firenza coupé promotional material for the Canadian launch, a market in which the car was a disaster (left) and 1975 High Performance (HP) Firenza "dropsnoot".  GM in South Africa actually made a good car out of the Firenza coupé, building 100 (for homologation purposes) with the 302 cubic inch (4.9 litre) V8 used in the original Z/28 Chevrolet Camaro.  In South Africa, they were sold as the "Chevrolet Firenza".  

In 1973, officially, Vauxhall called their new version of the Firenza coupé the “High Performance (HP) Firenza” but quickly the press, noting the Concorde (then still three years from entering commercial service), dubbed it the “droopsnoot”, the reference obviously to the distinctive nosecone designed for aerodynamic advantage.  The advantages were real in terms of performance and fuel consumption but Vauxhall had the misfortune to introduce the model just as the first oil crisis began which stunted demand for high-performance cars (BMW’s 2002 Turbo another victim) and triggered a sharp recession which was a prelude to that decade’s stagflation.  Vauxhall had planned a build of some 10,000 a year but in the difficult environment, a paltry 204 were built.

A Ford Escort Mark 2 in the 1977 Rally of Finland (left) and a 1976 Escort RS2000  with the droop snoot (right).

In 1976, Ford launched their own take on the droop snoot, the Mark 2 Escort RS2000 featuring a similar mechanical specification to that of the Mark 1 but with a distinctive nosecone.  Ford claimed there was an aerodynamic benefit in the new nose but it was really a styling exercise designed to stimulate interest because the Escort was the corporation’s platform for rallying rather than something used on high-speed circuits and it certainly achieved the desired results, the model proving popular.  Ford Australia even offered it with four doors as well as two although emission regulations meant the additional horsepower on offer in Europe was denied to those down under.  Interestingly, although the range’s high-performance flagship, the factory rally team didn’t use the droop snoot version, those in competition using the standard, square-fronted body.

Godox Pro Snoot S-Type Mount SN-05

Ogee

Ogee (pronounced oh-jee)

(1) A double curve, resembling the letter S, consisting of two arcs that curve in opposite directions so that the ends are parallel.   An ogee is a kind of sigmoid curve, technically formed by the union of a concave and a convex line.

(2) In architecture, a molding with such a curve for a profile; cyma, also called gula or talon.

(3) In fluid mechanics, a specific aerodynamic profile.

(4) In mathematics, an inflection point.

(5) In cosmetic surgery, a desired shape for the curve of the malar or cheekbone prominence transitioning into the mid-cheek hollow.

(6) In distillation, the bubble-shaped chamber of a pot still connecting the swan neck to the pot which allows distillate to expand, condense and fall back into the pot.

1275-1325: From the Middle English ogeus (plural oggez), ogeve, egeve & egeove, variants by assimilation from the French oggif (diagonal rib of a vault) from the Old French œgive, ogival, ogive & augive, from the Late Latin augiva of uncertain origin.  In the Late Latin there was ogis (a support, prop), thought derived from the Classical Latin augeō (to increase, strengthen) from which Spanish gained auge (highest point of power or fortune; apogee); a doublet of ogive.  The use in architecture to describe regular & irregular S-shaped moldings began in the 1670s, supplanting the earlier augive, from the Late Latin augiva of uncertain origin but perhaps related to the Latin via (way; road).  In the Middle English, the late thirteenth century ogif was "a stone for the diagonal rib of a vault", derived from the French and the Medieval Latin ogiva.

An Ogee arch.

An ogee is a curved shape vaguely like an “S”, consisting of two arcs that curve in opposite senses, so that the ends are tangential.  In architecture, it’s used to describe a molding with a profile made by a lower concave arc flowing into a convex arc.  Used first in Persian and Greek architecture from Antiquity, it’s most familiar now as a part of the Gothic style.  Because the upper curves of the ogee arch are reversed, it’s not suitable where the load-bearing rates are high and it’s thus used mostly in self-supporting structures exposed to their own weight and not subject to high external forces.

An inflection point.

In mathematics, an ogee is an inflection point, a point on a curve at which the sign of the curvature (ie the concavity) changes; inflection points may be stationary but are neither local maxima nor local minima.  Inflection Points merely mark the point on the curve where it changes from concave upward to concave downward (or vice versa), it is not a directional measure.  Calculus is needed to find where a curve goes from concave upward to concave downward and for this mathematicians use derivatives, one which determines the slope and a second which defines whether the slope increases or decreases.

The cosmetic surgeon's template.

When cosmetic surgeons speak of the ogee curve, they’re referring to the elongated S curve which, when looking at a patient’s face at a three-quarter aspect, describes the curve from the eye through the cheek down to below the cheek (technically the malar or cheekbone prominence transitioning into the mid-cheek hollow).  As people age, the face loses volume in our face and the ogee curve flattens out. With facelifts and related procedures, the cosmetic surgeon aims to create an ogee curve, restoring the chiseled refinement of youth.

Lindsay Lohan, Cosmopolitan, October 2022 edition (photographs by Ellen Von Unwerth (b 1954)).  The photographs illustrate the ideal ogee curve in the facial structure and Ms Lohan shows how a model's pout can be used to optimize the effect.  The car is a second generation AMC Javelin (1971-1974).

Shapes derived from the ogee curve are popular design motifs used for just about everything where they can be applied but it's most associated with large, flat surfaces because it's in such spaces the geometric repetition can be most effective, thus the prevalence in fabrics, wallpaper and floor-coverings.  The mind visualizes the shape as something like a two-headed onion and it's probably the association with the architectural style so often seen on mosques or other structures in the Arab world that in there's presumed to be some Islamic influence but ogee long pre-dates Islam.  There are few conventions of use except that the designs tend to be displayed in either a horizontal or vertical aspect; diagonal deployment is rare.

In fluid mechanics, the ogee describes the shape used to create certain aerodynamic profiles, the classic example being the delta wing of the Concorde airplane.  The ogee-type wing used on the Concorde one flavor of the compound delta (sometimes called double delta or cranked arrow) where the leading edge is not straight.  Typically the inboard section has increased sweepback, creating a controlled high-lift vortex without the need for a foreplane and the shape of the sweepback is defined by the parameters of the ogee.  On the Concorde, the two sections and cropped wingtip merge into a smooth ogee curve.

Delta

Delta (pronounced del-tuh)

(1) The fourth letter of the Modern Greek alphabet (Δ, δ).

(2) The consonant sound represented by this letter.

(3) The fourth in a series of items.

(4) Anything triangular, an allusion to the Greek capital delta (Δ).

(5) In mathematics, an incremental change in a variable, as Δ or δ.

(6) A nearly flat plain of alluvial deposit between diverging branches of the mouth of a river, often, though not necessarily, triangular.

(7) A word used in communications to represent the letter D (usually initial capital letter); Used in the ICAO (International Civil Aviation Organization) radiotelephony spelling alphabet (usually known as the NATO phonetic alphabet).

(8) In astronomy, a star that is usually the fourth brightest of a constellation (initial capital letter).

(9) In computing, a small but noticeable effect or the set of differences between two versions of a file; in informal use, a small but noticeable effect.

(10) In surveying, the angle subtended at the centre of a circular arc.

(11) A type of cargo bike that has one wheel in front and two in back.

(12) In electrical engineering (often attributive), the closed figure produced by connecting three coils or circuits successively, end for end, especially in a three-phase system.

(13) In finance, the rate of change in an option value with respect to the underlying asset's price.

(14) In chemistry, a value in delta notation indicating the relative abundances of isotopes or relating to or characterizing a polypeptide chain that is one of five types of heavy chains present in immunoglobins.

(15) In aerodynamics, a type of wing.

(16) The NATO code name for a class of Soviet nuclear-powered ballistic missile submarine armed with sixteen multi-warhead missiles.

(17) In physics, of or characterizing the atom or radical group that is fourth in position from the functional group of atoms in an organic molecule.

(18) In US Space Force use, a unit, nominally headed by a colonel, equivalent to a USAF operations wing, or an army regiment.

(19)   In electrical engineering, the closed figure produced by connecting three coils or circuits successively, end for end, especially in a three-phase system.

Circa 1200: From the Middle English deltha from the Latin delta from the Ancient Greek δέλτα (délta), from the Phoenician dalet & daleth (tent door).  It was akin to the Hebrew dāleth.  It was the fourth letter of the Greek alphabet (equivalent to the Modern English D) and was shaped like a triangle (Δ).  The sense of a delta being a "triangular island or alluvial tract between the diverging branches of the mouth of a great river" is because the Ancient Greek writer Herodotus (circa 484–circa 425 BC) used it to describe the mouth of the Nile River (now known as the Nile Delta).  That was picked up in English during the 1550s and applied to other river mouths (often of quite different shapes) by 1790.  The related forms are deltaic and deltification.  In pre-modern medicine, the deltoid muscle (the large muscle of the shoulder; triangular, resembling the Greek letter delta) was described in 1758, the name from the Ancient Greek deltoeides (triangular, literally "shaped like the letter delta).  In modern use, the "deltoid muscle" gained the short-form “delts” in 1977.  The related form is deltoidal.

The delta-wing

Gloster Javelin (1951-1967).  The first twin-engined delta-wing in service, the Javelin was the UK’s long-term solution to its need for an all-weather interceptor, the post-war technology gap until then filled by the stop-gap Gloster Meteor and that most improbable cold-war fighter, the de Havilland Mosquito.  The Javelin was the last aircraft to bear the Gloster name, the company absorbed into the morass created by the mergers, acquisitions and nationalization that befell British industry between Attlee and Thatcher. 

In aviation, the delta shape pre-dated aircraft by centuries, triangular stabilizing fins for rockets described in the sixteenth and seventeenth centuries and the first lifting wing in delta form patented in 1867 for use by a dart-shaped, rocket-propelled airplane.  However, although there were prototypes and much theoretical work was done during the first half of the twentieth century, it wasn’t until the late-1940s when jet propulsion made possible high-speed subsonic and supersonic flight that it was possible to build airframes which could take advantages of the delta-wing’s unique properties.

Lockheed SR-71 Blackbird (1963-1999).  A product of Lockheed’s Skunk Works, although in development as a high-altitude interceptor since 1959, the US government didn’t admit the SR-71 existed until 1964 and decided ultimately to use it for reconnaissance and research into supersonic flight.  The SR-71 in 1976 set the world record for the fastest flight by an air-breathing manned aircraft and the mark still stands.

The delta form offers structural advantages and aerodynamic characteristics suited to the fluid dynamics of airflow in supersonic conditions.  To suit different applications, design variations have evolved, with and without additional stabilizing surfaces.  The long root chord of the delta wing and minimal structure outboard is inherently structurally efficient, able to be built stronger and stiffer yet lighter than a swept wing of equivalent lifting capability.  It’s thus simple and relatively inexpensive to build.

Avro Vulcan (1956-1984).

Until the UK adopted the submarine-launched Polaris missile system, the Vulcan was the platform for the UK’s independent nuclear deterrent and it remained in service long enough to be deployed for its only combat mission, a flight of five aircraft used for (conventional bombing) missions during the 1982 Falklands War.  Each aircraft flew almost 4000 miles  (6,500 km) from Ascension Island, Victor tankers used for the air-to-air refueling, almost 1.1 million gallons (5 million litres ) of fuel burned each mission.

The long root chord also allows a deeper structure for a given aerofoil section, providing more internal volume for fuel and other storage without a significant increase in drag although, on supersonic designs, designers often take the opportunity to use a thinner aerofoil instead, thereby further reducing drag.  Usefully, the large root chord also provides a large surface area which assists in reducing the minimum speed; a low landing speed being a design objective in most military and civil applications.  Delta wings can be designed to induce vortex lift, so flow separation can be turned into a means of increasing lift and the whole structure is naturally stable in pitch, therefore not requiring a separate tail surface.

Aérospatiale/BAC Concorde (1969-2003).

The Anglo-French supersonic passenger jet operated commercially between 1976-2003.  Flying at twice the speed of sound and carrying up to 128 passengers, it was the longest lasting of its time, the Soviet Tupolev Tu-144 in passenger service only for a few years during the 1970s after which it operated both as a freighter and a research platform and the American SST never progressed beyond engineering mock-ups.  The Americans worked out the economics were never going to make sense; the Soviets had a different relationship to money and the Concorde lasted as long as it did only because the French & British governments wrote-off the development costs.

There are drawbacks.  The large wing area creates more viscous drag for the same amount of lift compared to a high aspect ratio wing; swept wings have a better lift-to-drag ratio than deltas.  Also, high-lift devices like fowler flaps are hard to integrate into delta wings with the rearward location of the trailing edge producing intolerable pitching moments when such flaps would be deflected.  In short, delta wings are superior only in supersonic flight; their best known design probably the Anglo-French Concorde.

Lindsay Lohan in delta skirts.

A delta skirt is characterized by its triangular shape, an allusion to the Greek letter delta (Δ); almost always, a delta skirt is fitted at the waist, flaring out towards the hem, creating the triangular silhouette.  The concept is adaptable and can be made from just about any fabric, the most popular including cotton, taffeta, silk and a variety of other synthetics.  Delta skirts tend to be shorter because to produce the triangular effect as length increases either some sort of internal structure is required or additional material needs to be used, increasing bulk and weight.  Although most associated with younger women, they have been adopted by a number sub-sets from the anime aesthetic, Goths and bohemians to hippies.