Illusion

Illusion (pronounced ih-loo-zhuhn)

(1) Something that deceives by producing a false or misleading impression of reality.

(2) The state or condition of being deceived; misapprehension.

(3) An instance of being deceived.

(4) In clinical psychology, a perception, as of visual stimuli (optical illusion), that represents what is perceived in a way different from reality.

(5) A very thin, delicate tulle of silk or nylon having a cobwebbed appearance, for trimmings, veils and similar designs.

(6) The act of deceiving; deception; delusion (mostly obsolete).

1340–1350: From the Middle English, from the Latin illūsiōn(em), stem of illūsiō, (irony, mocking), the construct being illūs(us), past participle of illūdere (to mock, ridicule) + lūd (play) + tus (past participle suffix) + iōn.  The suffic -ion was From the Middle English -ioun, from the Old French -ion, from the Latin -iō (genitive -iōnis).  It was appended to a perfect passive participle to form a noun of action or process, or the result of an action or process.  It was from the Latin lūd that English ultimately gained ludicrous, illudere meaning "to mock at" (literally "to play with").  The borrowing from Latin displaced the Old English dwimmer, from the Old English ġedwimor or dwimor (illusion, delusion, sleight, magic) and, as absorbed by both Medieval English & French, meaning tended towards “act of deception” rather than “mocking or irony” which was the Classical Latin form.  The English sense is reflected in the word’s use in Church Latin which is thought the source of the meaning-shift.  In modern English use, particularly since the rise of mass-market visual entertainment, to some extent the preponderant meaning has shifted back.  Illusion & illusionist are noun, illusionary, illusional and illusioned are adjectives; the noun plural is illusions.

English offers many variations on the theme; words like fantasy, hallucination and delusion all refer to false perceptions or ideas.  An illusion is either (1) a false mental image produced by misinterpretation of stuff that actually exists or (2) a deliberate creation in some form to create an impression of stuff in a way not real.  A mirage is a distortion of reality produced by reflection of light against the sky but in general use is widely deployed as a synonym for anything illusory. A hallucination is a perception of a thing or quality that is either wholly or partially unreal.  A delusion is a persistent false belief that need not have any basis.  A chimera is something which, while unreal, has many elements of the real and thus seems more plausible.  A fantasy is either (1) a fictional creation where one is aware of its untruth or (2) a fictional creation one believes.

The Illusion Panel

Used by fashion designers, the illusion panel is a visual trick which to some extent mimics the appearance of bare skin.  It’s done with flesh-colored fabric, cut to conform to the shape of wearer and the best known products are called illusion dresses although the concept can appear on other styles of garment.  Done well, the trick works, sometimes even close-up but it’s ideal for photo opportunities.  Lindsay Lohan illustrates the idea in three outfits:

Left: A gown from the Fendi Spring/Summer 2016 collection, worn at the Asian Awards, London, April 2016.  This may have been something of an "in joke" because although it looked like an illusion dress, the "cut-outs" literally were "cut out" and the skin was all Ms Lohan's own; fashion faking itself.  Reactions may have been something like on journalist’s comment to the Irish-born UK politician Brendan Bracken (1901–1958): “Everything about you is phoney. even your hair, which looks like a wig, isn’t.”  The playfulness continued above because above the modest cut at the midriff were translucent panels which created a nice effect, especially when in motion although opinion was divided on whether the geometric pattern was too busy for the concept, some suggesting a solid color or even some bold stripes might have lent better emphasis.

Centre: The Julien Macdonald (b 1971) green and blue sequin embellished mini dress with an open neckline was accented with a black hemline and came from the house's Fall 2013 collection.  Ms Lohan wore the piece at Gabrielle's Gala, Old Billingsgate Market, London, May 2014, provoking some comment about the choice not to retain the black belt with which it was paired on its catwalk debut and it's true that did work well with the hemline trim, width and shade of both matching.  However, what dominated the look was the illusion which was more a "wrap-around" than a panel and with things being that illusory, accessories really weren't demanded and probably it was more effective with neither belt nor necklace to distract.

Right: Dating from January 2013, the black Dion Lee (b 1985) cocktail dress used the technique featuring both the wearer's real skin (witness the off-the-shoulder silhouette) with illusion panels made of fabric of a matching hue; the shoes were Christian Louboutin (b 1964, he of the red soles) peep-toe booties.  It’s a classic example of why most think illusion dresses work best if tailored in solid colors with a marked contrast between material and skin tone.

Kylie Jenner (b 1997, left) in 2017 used the idea in what was (by the standards of her clan) quite subtle but trolls quickly realized the possibilities offered by digital editing (centre).  Swedish musician Tove Lo (Ebba Tove Elsa Nilsson, b 1987, right) actually enhanced the illusion with a T-shirt which included shadow effects so the look would be consistent even in settings where ambient light was unhelpful.  Pairing the T-shirt with an oversized, double-breasted teal blazer was a nice touch.

Ms Jenner’s interest in transparency is more than surface-deep.  In 2025, in response to a fan’s enquiry, she revealed (what could, in the social media age, be thought a kind of “product disclosure statement”) the technical details of her much-admired breast augmentation procedure:  Performed by plastic surgeon Dr Garth Fisher (b 1958), the silicone implants were a displacement of 445 cm3 with a “moderate profile” (a measure of “projection or fullness”), placed using the “dual plane” technique (in which the implant sits partially under the pectoral muscle and partially under the breast tissue).  According to Dr Fisher, the combination of a moderate profile and the dual plane method produces the “most natural look”.  While obviously, in a sense, an illusion, the result looked good enough to be “real” so according to theories of cognition, in another sense they are real.  Almost instantly, the combo was being spoken off as “the Kylie Special” but Dr Fisher cautioned the variables (implant construction & size, profile, installation technique etc) need to be assessed on a patient-by-patient basis because what suits one may not suit another.  Essentially, the advice was YMMV (your mileage may vary).

Model Kate Moss (b 1974) in a Stella McCartney (b 1971) illusion dress from her label’s Winter 2012 collection, London Eveningwear Presentation & Dinner, London, February 2012.

As a garment, an illusion dress is not technically difficult to cut or assemble but for its effect it relies on a close congruence between the colors of panel and the skin.  Assuming such fabrics are either available or can be dyed to suit, that’s fine for bespoke creations but in the vastly bigger prêt-à-porter (ready-to-wear) market, buyers are compelled to pick whatever is the closest match, the technique of choice being to alter the skin tone for the occasion, fake tanning product the usual choice which is fine if a darker hue is needed but when lightening that’s needed, the creams used temporarily to cover tattoos are said to work well, better even than the (now often controversial and in some cases dangerous) skin-lightening preparations popular in some markets.  On the catwalks, it's not unusual for creams and various forms of "tanners" to be used if it necessary to have skin-tone and fabric match.

Model Ashley Graham (b 1987, left) in cage bra with the focus on flesh under a "curtain reveal" and singer Ricki-Lee Coulter (b 1985 right) in a (sort of) dress with an illusion panel under the strappings.

The illusion industry variously exchanges and borrows motifs.  A cage bra is built with a harness-like structure which (vaguely) resembles a cage, encapsulating the breasts using one or more straps (which can recall the struts used in airframes or the futtocks which are part of nautical architecture.  Few actually use the straps predominately to enhance support and the effect tends to be purely aesthetic, some cage bras with minimal (or even absent) cup coverage and a thin band or multi-strap back.  Some things about cage bras can be illusory but the skin on show is usually real whereas when used over a skin-toned panel, the straps exist to enhance the illusion although, there’s no reason why they can’t also be structural, functioning effectively as an external bra.  

Illusion bra in red with flesh tone panels.

Many bras purposefully are designed to create an illusion of some sort (bigger, smaller (despite what men tend to believe the “minimizer” concept really is a thing), higher etc) but there is a class of cups which borrows its motif from the illusion dress and, like the dress, there’s an art to the illusion bra and a successful execution seems best achieved when adopting the “less is more” approach; smaller panels well-placed creating a more effective illusion than using too much surface area.  In some cases illusion bras are structurally identical to a conventional model, the only difference being the use of a flesh tone fabric in certain parts of the cup.  The most dramatic effect is achieved when built using the cage bra model but most implementations tend to be more modest.  To achieve the best match with human skin, the fabric of choice is often a de-lustred satin and given the cultural sensitivities, such things are no longer advertised with the phrase “skin-tone”.

The Great Illusion (1910) by Norman Angell (1972-1967) was first published in the United Kingdom in 1909 as Europe's Optical Illusion.  Angell’s theme was that the economies, financial systems, markets and supply chains of the world’s big industrial and military powers had become so inter-twined and inter-dependent that war had become impossible.  Angell proved that not only would war be unprofitable, in any big conflict, the victor would suffer at least as much as the vanquished so no nation would be so foolish as to start one.  Quickly, The Great Illusion was translated in eleven languages and in the optimistic world of early twentieth century Europe, it became a cult, its thesis a dogma.  The aristocrat commissioned to review the British Army after its disastrous performance in the Boer War (1899-1902) were understood instantly became an adherent to the idea that “new economic factors clearly prove the insanity of aggressive wars”, delivering lectures in which he pointed out that “a twentieth century war would be on such a scale… that its inevitable consequences of commercial disaster, financial ruin and individual suffering [would be] so pregnant with restraining influences” as to render the thought of war unthinkable.

Read even now, the wealth of examples he offered and the incontrovertibility of his argument seem convincing.  Unfortunately, Wilhelm II (1859–1941; Kaiser (Emperor) of the German Empire 1888-1918), although it’s known he received a copy of the book, was more influenced by one published in 1911 by the Prussian General Friedrich von Bernhardi (1849–1930) with the unambiguous title Deutschland und der Nächste Krieg (Germany and the Next War).  Bernhardi’s text is of great interest to students of military, diplomatic and political history but the casual reader can gain the necessary understanding merely by glancing at the table of contents, the uncompromising chapter headings including The Right to Make War, The Duty to Make War and World Power or Downfall.  In case anyone might have thought he had written a work of abstract theory, another chapter was titled Germany’s Historical Mission.   Describing war as a "divine business", his central two-pronged strategy was the one which would doom both the Second Reich and the Third: Wage wars of aggression and ignore treaties.

World War I (1914-1918) was something probably worse than even Angell had prophesized and in its aftermath the phrase “the war to end all wars” was popular although some of the delegates leaving Paris after the Treaty of Versailles (1919) weren’t so sanguine, reckoning all that had been gained was a truce with estimates of its duration ranging between 10-25 years.  Despite the cynicism however, the 1920s were the years in which the (now mostly forgotten) successes of the League of Nations (1920-1946) included the notion that war had been made not only unthinkable (both because of Angell’s analysis and the shock of what was then called "the World War") but actually unlawful.  It was a brief, shining moment and by 1933 Angell felt compelled to add to a revised edition of The Great Illusion the new theme of the need for collective defense.  Other things happened in 1933, the implications of which would mean that too would prove an illusion but that year, Angell was awarded the Nobel Peace Prize.

Illusions however seem to be something to which men can’t help but be drawn and by the late twentieth century, as globalization 2.0 accelerated, another part of Angell’s conceptual framework gained a new audience.  Angell had noted the obvious: That the imperative of modern capitalism was profit, not romantic nationalism and that there was more to be gained from peaceful trade than attempts at conquest with its unpredictable outcomes.  By the 1990s, political commentator Thomas Friedman (b 1953) had reduced this to what came to be called the Golden Arches Theory of Conflict Prevention (the idea that countries with McDonalds restaurants didn’t go to war with each other) and while that’s since been proved untrue (few rules apply in the Balkans), the point he was making was the same as Angell: That democracies run according to the rules of market capitalism don’t go to war with each other because the it’s too threatening to the hegemonic class which owns the means of production and distribution.

By the time Mr Putin (Vladimir Putin, b 1952, president or prime-minister of Russia since 1999) began his special military operation (the invasion which started the Russia-Ukraine war in 2022), it’s doubtful there were many left in Europe with illusions about the nature of man.  Unfortunately, it may be that in the Kremlin the reading of Bernhardi may not have gone beyond those first few bellicose chapters because deeper into his book, the author moved beyond the justification of “necessity” to the nuts and bolts of “method” for once one convinces one’s self one has a duty to make war, one must ensure it is waged with success.  To be successful he explained, the state must begin a war at “the most favourable moment” of its own choosing, striking “the first blow” in a manner which guarantees victory.  Mr Putin had illusions of his own, about the people of Ukraine, about the West and about the state of his own military.

In 2014, an illusion outfit attracted much comment when the Colombian women’s cycling team uniform was first seen at an event in Italy, held in honour of former Italian champion Michela Fanini (1973–1994).  Despite the appearance, it wasn’t a two-piece, the otherwise standard strip augmented by a (vaguely) flesh-coloured section across the lower torso and upper hips.  The photographs caused a stir and the unusual degree of international attention must have pleased the team’s sponsor, the city government of Colombia's capital, Bogota.  Innovations like this might be one way to redress the imbalance in the media coverage afforded to women's sport.

Entasis

Entasis (pronounced en-tuh-sis)

(1) In architecture, a slight convexity given to a column or tower, claimed to correct the optical illusion of concavity and create the perception of straight lines.

(2) In medicine and physiology, an involuntary or spasmodic muscular contraction (also called entasia (from the Greek ɛnˈteɪzɪə)).

(3) In typography & calligraphy, the thinning in the waist of a stroke, the technique used to compensate for the visual perception of a stroke with perfectly straight sides appearing slightly to bulge.

1745–55: From the Latin entasis, from the Ancient Greek ἔντασις (éntasis) (tension, straining), from εντείνω (enteínō) (to stretch or strain tight), the construct being enta, variant stem of enteínein (to stretch tight) + teínein (to stretch) + sis.  The –sis suffix was from the Ancient Greek -σις (-sis) and was attached to words in English often via Latin or French.  It was identical in meaning with the Latin –entia and the English –ing and was used (1) to form nouns of action or process (catharsis, dialysis, diagnosis, crisis etc), (2) in medicine to form nouns of condition (psoriasis, sepsis, tuberculosis, psychosis etc) and more generally (3) nouns as required (basis, oasis, thesis, stasis etc).  Entasis is a noun; the noun plural is entases.

The Entasis or Parthenon Principle

The Parthenon in Athens; it's the most celebrated use of entasis.

In modern architecture, entasis is the application of a convex curve to a surface for aesthetic purposes.  Its best-known use is in the columns from antiquity which curve slightly as their diameter is decreased from the bottom upward.  Because no relevant documents have yet been discovered, it’s not known whether the architects in antiquity applied the technique for aesthetic effect or as an engineering technique to enhance strength.  The latter is suggested by the design principle being described by Roman architect Marcus Vitruvius Pollio (circa 75 BC–circa 20 BC) using the Greek word enteino (to stretch or strain tight), suggesting some emphasis on structural strength rather than appearance.  However, until contemporary records are uncovered, their reasons for using entasis remain mysterious, hence the two-thousand odd years of conjecture.  The earliest known documented view of the matter was that written by Greek mathematician and engineer Hero of Alexandria (circa 10-circa 70), is that entasis corrects the optical illusion of concavity in the columns that the human eye would create if the correction were not made.  

Basilica's western front of the Second Temple of Hera, a Greek temple in Paestum, Campania, Italy.

The Second Temple of Hera (circa 55 BC) was built in the Doric order, just north of the first.  For the visual effect of entasis to work, the convex curve has to be so slight as to be imperceptible and it's not known why the Second Temple of Hera has an entasis so pronounced the curvature is obvious; there is illusion of straightness.  The proportions are such that historians have speculated it must have been deliberate (presumably for structural strength) but it's at least possible the architect was afflicted by the desire many of his modern contemporaries share: The wish to produce something "original" and "new", the reason why so many modern buildings are so unpleasing to the eye, architectural awards & prizes handed out not for beauty and elegance but novelty and shock.

For millennia, entasis and its place in the history of architecture has been one of the most persistent tales from Antiquity but there have long been contrarians prepared to argue the concept, while not exactly a myth, is greatly exaggerated in significance.  In September 2026, Belgian mathematician Professor Alain Goriely (b 1967; professor of mathematical modelling at the University of Oxford) published the findings of his study, challenging the belief the Parthenon’s “curves” were included to correct “optical illusions” that would have made pure straight lines appear “distorted”.  What the professor’s modelling was said to reveal was (1) the “curves” are practically imperceptible and the alleged “illusion” they were claimed to correct doesn’t exist; “the illusions are illusory”.  Deconstructing Vitruvius, the study begins with the claim the sides of the Parthenon’s stylobate (base) are not horizontal but form a very flat “V”, rising gently 60 mm (2.36 inches) towards the centre.  According to Vitruvius, this was to correct the illusion that, when viewed as a whole, the base appears to “sag in the middle”.  For centuries, the “sagging effect” was attributed to one of two “tricks of the light”: (1) That because of the way light is interpreted by the human brain, long horizontal lines “appear to slump” towards the centre or (2) That the structure’s marble columns create the illusion; this based on the “Hering illusion” (where in 2D (two dimensions) parallel lines can appear “bowed” when intersected by other lines).  Professor Goriely found nothing to support either proposition, noting the Hering illusion (discovered in 1861 by German physiologist Ewald Hering (1834--1918) is most apparent when lines intersect at acute angles and the Parthenon’s columns are anyway “too close to the vertical” to produce the illusion.  Additionally, extensive modelling produced no proof the effect would manifest on the Parthenon even in 3D (three dimensions), viewed from any angle.

The persistent claims of entasis.

Those details were really footnotes in architecture textbooks, entasis the most famous of the legends.  What that suggests is “bulges” in the Parthenon’s columns (the curvature called entasis) were included by the builders to correct an optical illusion that would make them appear “too narrow” in the middle.  Not only did Professor Goriely found no evidence the illusion exists but the columns bulge by a mere 18 mm (less than ¾ inch) which, at that scale, is simply not perceptible to the human eye at a typical viewing distance.  What he doesn’t dispute is the architects may have had some reason to include variations in the dimensions; it’s just he found no evident they were there as “optical correctives”, the slopes on the base perhaps there for a reason as mundane as preventing puddles forming after rain; as every builder knows, only a very slight incline is needed for water to flow.  The very minor increase in width in the columns’ centre sections is more mysterious and may have been something to do with what would have been a very labor-intensive production process but there seems to be no optical effect.

Beyond the math, Professor Goriely speculates the reason the myth has proved so enduring was the extraordinary level of veneration granted to the engineers, philosophers and architects of Antiquity when, in the late Medieval period and (especially) the Renaissance, so many of the texts were “re-discovered” and a the perception emerged of Ancient Greece as a supremely knowledgeable and ingenious civilisation.  For centuries, in Western Europe, the Classical World was idealized and unless explicitly disproved (as came to be done of their medicine, cosmology and such), the texts were treated with great respect, thought something of “Civilization’s gold standard”.  In the modern age, the veracity of what Vitruvius wrote tended to be reinforced by internet users repeating the tale, search engines affording a greater credibility to “facts” appearing in the greatest volume.  Now of course, AI (artificial intelligence) bots have centuries of architectural texts from which to harvest information and given what Vitruvius who wrote about the Parthenon (400 years after its construction), came to be treated as something “scriptural” (despite the loss of loss of the many Greek texts about their temple architecture he claimed to have read when preparing his own), the authority was strengthened.  Untypically for an academic paper, the professor recommends not too much dwelling on his findings but commending instead: “Trust your own eyes, question what you see and decide for yourself whether the theory of optical corrections holds up.”  Professor Goriely concluded entasis “might be the oldest myth that we have” before mischievously adding “apart from religion.”

1964 Rolls-Royce Silver Cloud III Flying Spur; coachwork by H.J. Mulliner Park Ward.

One orthodoxy to emerge in the twentieth century was the famous Rolls-Royce radiator grille owed as much to Classical architecture as to being something there to prevent stones damaging the fragile core behind; if Rolls-Royce was going to be influenced by anyone, it’d be the architects of Antiquity.  According to chapter 4 of The Lexicon of Rolls‑Royce (the company doesn’t have web pages, it has chapters), what it styles as the “Pantheon Grille” was “…inspired by Rome’s imposing Pantheon temple, the Rolls-Royce grille is iconic. The Pantheon’s majestic columns were purposefully built with wider middle sections so that the human eye perceives each long pillar to be completely straight. It’s a perfect optical illusion and a genius stroke of design.  Taking inspiration from this, the Rolls-Royce grille is tactfully arranged using wider columns at the edge and thinner columns towards the middle to create an aesthetic illusion of symmetry when admired from the front. It’s a design that appears more perfect than nature intended.”  The days are gone when Rolls-Royce’s documents were characterized by understatement (it once described its engines’ power outputs as “adequate”), the vulgar numbers revealed only when German regulators humorlessly insisted.

While Professor Goriely’s computer models could find no evidence of the effect, a century-odd earlier, Rolls-Royce’s designers were convinced by the optical tricks of the Greeks and in 1925 integrated one of their optical techniques their new grille.  Although the “squared-off” shell dates from shortly after the company’s formation in 1904, not until 1928 did the now familiar grille with its upright bars become standardized.  Prior to 1925, the radiators were fronted by horizontal “slats” best thought of as “louvers” in that they functioned like “venetian blinds” (controlled by a lever next to the driver) to enable the airflow to be controlled (thus regulating engine temperature).  By the time of the release of the model Twenty in 1928, improvements in thermal-management technology meant the slats were no longer needed so the designers could start with a “clean sheet” and, being Rolls-Royce, the went neo-classical and built their own Pantheon, refining the ideas first seem in 1925 on the “New Phantom” (known retrospectively as the “Phantom I” (1925-1931) after new generations of the model followed).  So, although Professor Goriely’s math couldn’t detect any evidence entasis produced a detectable effect for those looking at the Parthenon, what Rolls-Royce does has been modelled and although slight, the effect of their trick is real.

Lindsay Lohan in Rolls-Royce Phantom Drophead Coupé (2007-2017).  By the 1970s factory (mostly) had ceased to use the historic terms FHC (Fixed-Head coupé) and DHC (Drop-Head Coupé (DHC) and the revival in 2007 for the Phantom Drophead Coupé has proved (thus far) a nostalgic one-off.  Over the decades, the designers generally were successful in their adaptations as they were required to make the grille wider and lower but the Phantom would have benefited aesthetically if a more traditional approach had been taken with the headlamps (centre) and even hidden units (right) would have been more pleasing.  Still, twenty-first century customers seem more accommodating of stylistic innovation than earlier generations.

According to opticians, what the design does (wider bars at the edges, more slender towards the centre) is create the illusion of symmetry when viewed straight on (at even a slight angle there will be no effect).  That’s said to be because when viewing such a structure, the brain processes the image as a whole (not a sequence of individual bars) and, paradoxically, what the slight difference in width does is render an “artificial equalization”.   Because of the way the brain processes the sight of a series of “parallel bars”, were they equally-spaced and equally wide, there would be a “hollowing” effect with a “pinching” towards the centre, caused by the natural human tendency to perceive outer edges as tapering away.  The eye is an outgrowth of the brain and it’s the brain doing the processing; while “looking at a grill” might sound a simple task, in the Rolls-Royce grille there’s a lot of “information” and processing it all is an act of high-level cognition.

Hi-rise Pantheon: 1965 Rolls-Royce Phantom V.  This was about at tall as the grille got; it appeared on the Phantom V (1959-1968) & VI (1968-1990).

All else being equal, the brain tends first to focus on an image’s centre (that information sent to the fovea centralis (the part of the retina handling “sharp central vision”)) with the edges simultaneously entering the “peripheral vision” where spatial resolution decreases (the brain therefore gathering less precise detail about the outer dimensions).  All this happens in a fraction of a second but does still happen sequentially, the brain using “predictive modelling” to “fill in the blanks” and there is much to process, the grille a large, highly reflective three-dimensional object with repeating lines.  The brain’s visual cortex has much to do understand the contrasting light patterns and depth cues and that it does all this in a fraction of a second in an indication of how powerful a machine it is.  Additionally, Rolls-Royce further assists the brain in “manufacturing perfection by machining each bar with a very slight outward curve, not detectable to the naked eye.  The combination of this functionally imperceptible “width-shifting & curvature” uses the way the brain operates to induce the required corrective “shortcuts”.

The Pantheon Temple, Rome (left) and 1985 Rolls-Royce Camargue (right).

The Pantheon's Latin inscription M·AGRIPPA·L·F·COS·TERTIVM·FECIT isn't all that poetic and reads like a note the draftsman might have put on the blueprint (had there then been blueprints): it translates as "Marcus Agrippa, son of Lucius, made [this building] when consul for the third time.", crediting the Roman statesman & general, Marcus Vipsanius Agrippa (circa 63 BC–12 BC) who commissioned the construction during his third consulship in 27 BC.  The Pantheon that stands today was rebuilt by Emperor Hadrian (Publius Aelius Hadrianus, 76–138; Roman emperor 117-138) circa 126 AD after the original structure suffered severe damage in a blaze; Hadrian chose to retain Agrippa's inscription as a tribute (not all the emperors were narcissists).  Since 609 AD, the Pantheon has been a Roman-Catholic church and is known as the Basilica Santa Maria ad Martyres (Basilica of St. Mary and the Martyrs).   In 1975, when the Camargue (1975-1986) was released, the novelty of it being the first Rolls-Royce designed using exclusively metric measurements (except for the odd carry-over component) attracted little attention but there was much comment about it being the first built with anything but a perfectly vertical grille.  The Camargue's grille was slanted at a (for mid-century Rolls-Royce) rakish 7^o.

Waftability

Parthenon Grill, Murfreesboro, Tennessee.

Understandably, the malapropism “Parthenon grill” is sometimes heard (and there is a well-reviewed Greek restaurant in Murfreesboro, Tennessee of that name) and despite occasional claims, the Pantheon grille doesn't feature a classic entasis (slight swelling in the middle of a column to counteract the alleged illusion of concavity) but the slight curve of the bars is real and can be checked with equipment no more complex than a “straight-edge” (a 12 inch (300 mm)) metal ruler ideal for the purpose.  Although for much of the twentieth century Rolls-Royce was much associated with straight lines (the “knife-edge” models bodied by coach-builder Hooper between 1935-1959 the high point of the brief era of  blending of a severe rectilinearly with the flowing lines of the pre-war aesthetic although, despite the mix, the approach was not within the lineage of post-modernism) curves have often been a component and in 2009 Tom Purves (b 1949; CEO of Rolls-Royce Motor Cars 2008-2010) announced the neologism “waftability” was “the essence of the brand”.  That, he defined as “calm perfect motion and accelerating quickly without fuss”.  Back then (and 2009 seems now little less remote than the days of the Cold War (1947-1991)), the CEO was describing the relationship between the appearance of a static Rolls-Royce as something that embodied that definition, revealing the internal name for the “gentle, upswept line of the sill” on the new Ghost model was a “waftline” (actually borrowed from the fashion business), the idea being it created “a powerful, poised stance and makes the car appear to be moving when stationary.”

1988 Rolls-Royce Corniche Convertible.  Although rendered redundant by electric motors, the Pantheon Grille will endure; it will be wider and lower (as has already happened) and some functional use may even be found but as an essential element in “brand identity” it won't go away.

The significance of “waftability” was Rolls-Royce was then still in the business of making large-displacement engines running on fossil fuels sound and behave as if they were electric motors but, by 2023, the company announced the Spectre, the brand’s first purely electric car.  So it had taken a while but the interest in electric energy predated even the formation of the company in 1904.  Sir Henry Royce (1863–1933) was an engineer who had designed dynamos, electric crane motors and patented the bayonet-style light bulb fitting while Charles Rolls (1877–1910) as early as 1900 drove an electric car declaring it the almost ideal form of propulsion, observing: “The electric car is perfectly noiseless and clean. There is no smell or vibration, and they should become very useful when fixed charging stations can be arranged.  But for now, I do not anticipate that they will be very serviceable – at least for many years to come.”  So it proved.  By 2023 however, the technology was ready and so (more debatably) was the infrastructure and there is nothing better at waftability than something large, luxurious and electric, Rolls-Royce saying that some time in the next decade, their last car running on fossil fuel will leave the assembly line.  Nothing lasts forever and, having spent more than a century trying to make ICEs (internal combustion engine) as smooth and silent as electric motors, the times seem now to suit Rolls-Royce.  For others (such as Ferrari, Porsche, Dodge etc), selling to a customer base with an emotional attachment to the howl, throb & scream of gasoline (petrol) exploding in six, eight or twelve combustion chambers, the challenge is to find a way to make them content with a piped soundtrack.  Engineers have conquered matters of performance and even range but nostalgia may prove harder to package.  For Rolls-Royce however, the task is simpler because it’s purely visual: While an electric car needs no radiator and thus no protective grill, it can be guaranteed Pantheon Grilles, severely cut in stainless steel, will continue to appear.

Geodesic

Geodesic (pronounced jee-uh-des-ik or jee-uh-dee-sik)

(1) In spherical geometry, a segment of a great circle.

(2) In mathematics, a course allowing the parallel-transport of vectors along a course that causes tangent vectors to remain tangent vectors throughout that course (a straight curve, a line that is straight; the shortest line between two points on a specific surface).

1821: A back-formation from geodesy (a branch of science dealing with the measurement and representation of Earth, its gravitational field and geodynamic phenomena (polar motion, Earth tides, and crustal motion) in three-dimensional, time-varying space and with great (and "down-to-earth" as it were) practical application in surveying.  The adjectives geodesical & geodetic had first appeared in 1818 & 1819 respectively, both from geodetical which had been in use since the early seventeenth century.  All the forms are derive ultimately from the Ancient Greek γεωδαισία (geodaisía) from γῆ (geo) (earth) + δαιεῖν (daiesthai) ("to divide" or "to apportion") and the use in English was most influenced by the French géodésique, dating from 1815.  In general use, the word entered general use after 1953 when it was used of the "geodesic dome" (a structure built according to geodesic principles); despite the earlier use in wartime aircraft construction, the use there was only ever "engineer's slang".    Geodesic is a noun & adjective, geodesicity is a noun, geodesical is an adjective and geodesically is an adverb; the noun plural is geodesics.    The alternative adjectival form geodetic appeared in 1834 but fell from use by mid-century.  

Four-dimensional space-time.

Geodesic describes the curve that locally minimizes the distance between two points on any mathematically defined space, such as a curved manifold; essentially the path is the one of the most minimal curvature so, in non-curved three-dimensional space, the geodesic is a straight line.  Under Albert Einstein's (1879-1955) theory of general relativity (1915), the trajectory of a body with negligible mass on which only gravitational forces are acting (ie a free falling body), defines the geodesic in curved, four-dimensional spacetime.  Dictionaries and style guides seem to prefer “space-time” but scientists (and space nerds) like “spacetime” and because it was one of them who “invented it”, it seems polite to ignore the hyphen.  The term, a calque of the German Raumzeit (the construct in English being (obviously) space + time) first appeared in a paper by German mathematician Hermann Minkowski (1864–1909), published in the Philosophical Review.  The existence of the noun plural "spacetimes" does not imply something to do with the so-called multiverse (in cosmology, a hypothetical model in which simultaneously more than one universe exists) but rather that there are different space-times created in different places at different times.

General relativity fan girl Lindsay Lohan in optical illusion dress from the Autumn-Winter collection of interior designer Matthew Williamson (b 1971), illustrating an object causing the curvature of spacetime, Gift Global Gala, Four Seasons hotel, London, November 2014.  An “optical illusion dress” is one which uses a fabric print or other device to create the effect and differs from an “illusion dress” which is made with skin-tone fabrics placed to emulate the wearer’s own flesh.

In Einstein's theory of general relativity, gravity is treated not as a force as had been the historic understanding explained in the writings of Sir Isaac Newton (1642–1727) but rather as a curvature of spacetime caused by the presence of mass and (thus) energy.  The Sun, being a massive object, causes a (relatively) significant curvature in the surrounding spacetime and the Earth, as it moves through this curved spacetime, follows a path (a geodesic) which manifests as what appears to be an “orbit” around the Sun.  It is this curvature of spacetime that is perceived as the “gravitational pull” of the Sun on the Earth, keeping it in a (relatively) stable and predictable orbit.  Einsteinian physics supplanted Newtonian physics as the structural model of the universe and nothing has since been the same. 

Hull of Vickers R.100 Airship.

Sir Barnes Wallis (1887-1979) was an English engineer, best remembered as the inventor of the bouncing bomb used by the Royal Air Force in Operation Chastise (dubbed the "Dambusters" raid) to attack the Ruhr Valley dams during World War II and the big Tallboy (6 tonnes) and Grand Slam (10 tonnes) deep-penetration "earthquake" bombs.  Wallis had been working on the Admiralty’s R.100 airship when he visited the Blackburn aircraft factory and was surprised to find the primitive wood-and-canvas methods of the Great War era still in use, a notable contrast to the elegant and lightweight aluminum structure of airships.  He was soon recruited by Vickers to apply his knowledge to the new generation of fixed-wing aircraft which would use light alloy construction for the internal structure.  His early experience wasn’t encouraging, the first prototype torpedo bomber, which used light alloy wing spars inspired by the girder structure of R.100, breaking up mid-air during a test-flight.  Returning to the drawing board, Wallis designed a revolutionary structural system; instead of using beams supporting an external aerodynamic skin, he made the structural members form the aerodynamic shape itself.

The geodesic structure in an airframe.

The principle was that the members followed geodesic curves in the surface, the shortest distance between two points in the curved surface although he only ever referred to it in passing as geodetic; it wouldn’t be until later the label came generally to be applied to the concept.  As a piece of engineering, it worked superbly well, having the curves form two helices at right angles to one another, the geodetic members became mutually supporting, rendering the overall framework immensely strong as well as comparatively light.  Revolutionary too was the space efficiency; because the geodetic structure was all in the outer part of the airframe meant that the centre was a large empty space, ready to take payload or fuel and the inherent strength was soon proven.  While conducting the usual wing-loading stress tests to determine the breakage point, the test routine was abandoned because the wings couldn’t be broken by the test rig.

Vickers Wellseley.

The benefits inherent in the concept were soon demonstrated.  Vickers’ first geodesic aircraft, the Wellesley, entered service in 1937 and in 1938, three of them, making use of the massive fuel capacity the structure made possible, flew non-stop from Ismailia in Egypt to Darwin in Australia, setting a new world record distance of 7,158 miles (11,265 km), an absolute record which stood until broken in 1946 by a Boeing B-29 Superfortress; it remains to this day the record for a single-engined aircraft with a piston engine, and also for aircraft flying in formation.  While the Wellesleys were under construction, Wallis designed a larger twin-engined geodetic bomber which became the Vickers Wellington, the mainstay of the RAF’s Bomber Command until 1943 when the new generation of four-engined heavy bombers began to be supplied in in the volume needed to form a strategic force.  Despite that, the Wellington was still used in many roles and remained in production until after the end of hostilities.  Over eleven-thousand were built and it was the only British bomber to be in continuous production throughout the war.

Vickers Wellington fuselage internal detail.

The final aircraft of the type, with a more complex geodetic structure was a four-engined heavy bomber called the Windsor but testing established it didn’t offer significantly better performance than the heavies already in service, and the difficulties which would be caused by trying to replicate the servicing and repair infrastructure was thought too onerous so it never entered production.  Post-war, higher speeds and operating altitudes with the consequent need for pressurised cabins rendered the fabric-covered geodetics obsolete.

Aston Martin DB4 GT Zagato (one of 19 in the "Continuation Series", production of which began in 2019) during construction, an aluminium panel being attached to the superleggera frame, Aston Martin Works, Newport Pagnell, Buckinghamshire, England.

There are obvious visual similarities between the classic superleggera method and the geodesic structure used in airframes and some buildings, most famously the “geodesic dome”.  The imperatives of both were strength both aim to create strong and lightweight structures, but they differ in their specific design and application.  As used in airframes, the geodesic structure consisted of a network of intersecting diagonal braces, creating a lattice framework which distributed loads as evenly as possible while providing a high strength-to-weight ratio.  This was of great significance in military airplanes used in combat because it enhanced their ability better to withstand damage better, the stresses distributed across the structure rather than being restricted to a limited area which could create a point-of-failure.  The geodesic framework was based on geometric principles which had been developed over centuries and typically employed hexagons & triangles to render a structure which was both rigid & light.  Superleggera construction differed in that it involves the creation of a lightweight tubular frame, covered with aluminum body panels of a thinness which wouldn’t have been possible with conventional engineering.  The attraction of the superleggera technique was the (relatively) minimalistic framework supported the skin, optimizing weight reduction without compromising strength.  So, structurally, the difference was the geodesic design used a network of intersecting braces to form a lattice, while the superleggera construction used a tubular frame covered with panels.