Shadow

Shadow (pronounced shad-oh)

(1) A dark figure or image cast on the ground or some surface by a body intercepting light.

(2) Shade or comparative darkness, as in an area.

(3) As “the shadows”, darkness, especially that coming after sunset.

(4) A spectre or ghost.

(5) A mere semblance of something.

(6) A reflected image, as in a mirror or in water (now rare and restricted to literary or poetic use).

(7) In painting, drawing, graphics etc, the representation of the absence of light on a form.

(8) In art, the dark part of a picture, either representing an absence of illumination or as a symbolic device.

(9) In architectural depictions & renderings (as “shades and shadows”) a dark figure or image cast by an object or part of an object upon a surface that would otherwise be illuminated by the theoretical light source.

(10) In Jungian psychology, the archetype that represents man's animal ancestors; an unconscious aspect of the personality.

(11) In pop-psychology (1) a period or instance of gloom, unhappiness, mistrust, doubt, dissension, or the like, as in friendship or one's life or (2) a dominant or pervasive threat, influence, or atmosphere, especially one causing gloom, fear, doubt, or the like (often expressed as “shadow of fear”, “shadow of doubt” et al).

(12) A person who follows another in order to keep watch upon that person (in law enforcement, espionage etc).

(13) To overspread with shadow; to shade.

(14) To cast a gloom over; to cloud.

(15) To screen or protect from light, heat, etc; to provide shade.

(16) To follow and observe (a person).

(17) To represent faintly, prophetically etc. (often followed by forth).

(18) In democratic politics, (of or pertaining to a shadow cabinet or shadow minister) a system whereby an opposing politician formally is appointed to be responsible for matters relating to a particular minister’s areas of authority.

(19) As a modifier (shadow ban, shadow ticket, shadow docket, shadow price, shadow inflation etc), something effected unofficially or without public notice; characterized by secrecy or performed in a way that is difficult to detect; a clandestine approach.

(20) In typography, the “drop shadow” effect applied to lettering.

(21) An uninvited guest accompanying one who was invited (an obsolete, Latinism).

(22) In human resource management, the practice of new appointee accompanying an incumbent during the working day, so as to learn the job.

(23) In computer programming, to make (an identifier, usually a variable) inaccessible by declaring another of the same name within the scope of the first.

(24) In computing, in the graphical Workplace Shell (the WPS, successor to the Presentation Manager (PM)) of the OS/2 operating system, an object representing another object.

Pre-900: From the Middle English noun shadwe, shadu, shadue, shadowe shadow, from the Old English sċeaduwe, sċeadwe & sceadu, the oblique case forms of sċeadu (shadow, shade; darkness; protection).  The Middle English verbs were shadwen, shadwe, shadu & shadue (to shade, provide shade, cast a shadow, protect), from the Old English sceadwian (to cover with shadow, protect) (all derivative of the nouns), from the Proto-West Germanic skadu, from the Proto-Germanic skadwaz (shade, shadow), from the primitive Indo-European skeh & ḱeh- (darkness).  Contemporary forms included the Old Saxon skadowan & skadoian and the Gothic (ufar)skadwjan (to (over)shadow).  Similar forms in other Germanic languages included the Old Saxon skado, the Middle Dutch schaeduwe, the Dutch schaduw, the Old High German scato, the German schatten and the Gothic skadus (shadow, shade).  Shadow is a noun, verb & adjective, shadower is a noun, shadowdy, shadowless & shadow-like are adjectives; the noun plural is shadows.

The shadow-box was a protective display case, usually in the form of interlocking squares and wall-mounted was first advertised in 1892.  The term shadow-figure was a synonym of silhouette, dating from 1851.  Eye-shadow was a term invented for the commercial products which came onto the market in 1918, providing a convenient packaged product to achieve the look women (and apparently not a few men) had been creating for thousands of years.  Shadow-boxing was first noted in 1906, an update of the earlier (1768) shadow-fight.  The verb foreshadow (indicate beforehand was a figurative form, the idea apparently of a shadow thrown before an advancing material object as an image of something suggestive of what is to come.  It’s familiar also in the forms foreshadowed & foreshadowing and was used as a noun since at least 1831.  Although the meanings were different, in Old English there was forescywa (shadow) & forescywung (overshadowing).  The adjective shadowy was ultimately from late fourteenth century shadwi & shadewy (full of shadows, shaded (and also “transitory, fleeting, unreal (resembling a shadow)”).  From very late in the eighteenth century it conveyed the sense of “faintly perceptible”.  In The Old English there was sceadwig (shady) and the modern alternative is shadowiness but unfortunately, the marvelously tempting shadowous never caught on.  The noun shadowland came from a work of fiction in 1821 and meant “an abode of ghosts and spirits”, adopted from the early 1920s to mean an indeterminate or unhappy place”.  The noun shadowless was from the 1630s and meant literally “no shadow” the implication being of things ungodly or supernatural.

In idiomatic use shadow often appears.  To be a shadow of one's self is to have suffered some trauma meaning one is a lesser person than before.  One afraid of one’s own shadow is one of a skittish, nervous disposition.  If something is beyond a shadow of a doubt it is something certain.  The old expression sanctuary in the shadow of the church was not exactly literal: to seek sanctuary from the agents of the state by entering a church meant one had to pass through the door.  It referred to the noting that church soil in England was under the authority of the pope in Rome, not the King.  To throw (or cast) a shadow over someone is to seek to deny them visibility; to keep them out of the limelight.

1969 Rolls-Royce Silver Shadow.

In continuous production until 1980, the Rolls-Royce Silver Shadow was introduced in 1965 and with over 30,000 (including the less common but substantially identical Bentley T2 variant) built, it remains the Rolls-Royce made in the greatest volume.  Although there was little about the model which was cutting-edge, it was the first truly modern Rolls-Royce, forsaking the separate chassis, drum brakes and styling which used updated motifs from the 1930s; it was the template with which the company would underpin its products for the rest of century.  Although the huge Phantom V & VI limousines would continue to use a separate chassis until 1990, their annual production was measured (usually at most) in the dozens and it was the Silver Shadow and its derivatives which were the company’s bread and butter.  The adoption of unitary construction meant the end of the line for many specialist coachbuilders and some of the relics of the industry were absorbed by the factory, the Mulliner name still used by Bentley to adorn the even more expensive “special order” vehicles the 1% need to convey the message of wealth something "off the shelf" can’t manage.

1967 Rolls-Royce Silver Shadow two-door saloon by James Young (left) and 1971 two door saloon by Mulliner Park Ward (MPW) (right).

However, on the Silver Shadow platform, James Young, one of the last surviving coachbuilders, did build 35 two-door saloons before the business was shuttered in 1968.  The quirk of the James Young Silver Shadows is truly they were just the standard car with the rear-doors removed and the front units lengthened and it suffered because the competition was the two-door designed by Mulliner Park Ward (MPW) which by then was a specialist division within the factory.  With greater resources and access to all the technical data, the MPW effort was more imaginative and judged universally to be more attractive, its “cow-hip” style (nobody ever suggested using the "cokebottle" appellation Chevrolet & Pontiac had a few years earlier made a trend) carried over when the car was in 1971 re-named Corniche and listed as a regular production model.  The Corniche proved the longest-lived of all the Silver-Shadow family, the convertible (even Rolls-Royce eventually gave up calling such things drophead coupés (DHC)) remaining available until 1996.

Applied with different colors in different ways, eye shadow can achieve various effects.  Lindsay Lohan demonstrates.

The archeological evidence suggests eye shadow is one of humanity’s oldest forms of make-up, worn (usually but not exclusively by women) for thousands of years, and the preparations have included oils and a variety of substances to create the desired colours including minerals & vegetable extracts although charcoal is thought to have been one of the most accessible and popular materials.  The usual rationale for applying eyes shadows is that it’s essentially the same technique as chiaroscuro, a trick used by painters, photographers & film-makers to use real & emulated light and dark to achieve the perception of depth.  Because shadows are inherent to the shape of the eye-socket, eye shadow can be use to accentuate or soften the effect and, if applied with expertise, can even alter perceptions of size and shape.  With a sympathetic choice of shade, the color of the eyes can also be used as a contrast, some taking advantage of colored contact lens to create a look impossible with their natural irises.  Done well, there's no other way to describe the combination of eye shadow and purple contact lens that "eye catching".  Eye shadow can draw attention to the eyes, most trying to make them appear larger, more vibrant, or more expressive.  Despite the name, eye shadow is a flexible product and often used to create a visual illusion on body parts such as the cheeks or décolletage.

Shadow Volumes

Example of shadow mapping with Python summarized by FinFET.

In computer graphics, shadow volume is a technique used to render realistic shadows in three-dimensional (3D) renderings which is employed primarily when dynamic, interactive real-time movement is needed, most obviously in gaming.  Essentially, generating shadow volumes involves determining those addresses in a scene which need to appear as shadows, then rendering them accordingly.  The technique relies on the concept of extruding the boundaries of shadow-casting objects to create a "shadow volume" that represents the space occluded by the object.  In static scenes this was always easy (if once time-consuming) to achieve but when objects nwere moving, until recent decades, the graphics capabilities of computers were insufficient for them to be rendered in anything close to being real-time.  The process essentially is:

(1) Determining shadow casters: The rendering engine identifies objects in the scene capable of casting shadows by calculating the object's position and shape and its relationship to the positions of light sources.

(2) Creating shadow volumes: For each shadow-casting object, the engine constructs a shadow volume based on extending the object's silhouette (defined by the address of the boundaries) in the direction opposite to the light source.  The silhouette is determined by the math of the boundaries viewed from the perspective of the relevant light sources.

(3) Intersecting shadow volumes: The shadow volumes are then intersected with other objects in the scene to determine which parts of those need to be inside or outside the shadow.

(4) Rendering shadows: The shadow volumes are assembled, rendered with darker hues or modified shading techniques to simulate the shadowed regions.

Shadow volumes can be implemented using more than one different algorithm, the most commonly used the z-pass and the stencil buffer.  All techniques are computationally intensive and have been made possible by the advances in the sheer power and complexity of modern graphical processing units (GPUs).

The Microsoft Volume Shadow Copy Service (VSS)

The handy Nirsoft Utilities includes a Shadow Copy viewer.

Microsoft introduced Volume Shadow Copy Service (VSS) with Windows XP (2001).  It worked in conjunction with the High Performance File System (HPFS) and allowed for the creation of point-in-time snapshots or copies of files and volumes on a disk.  What was in 2001 still something of a novelty for most users was the snapshots were taken while the files were in use, enabling access to previous versions or the restoration of files to a specific state, even if they have been been modified or deleted.  The process sequence was:

(1) Snapshot creation: VSS creates a snapshot of a volume or individual files on a disk.  This snapshot represents a "shadow" of the data at a moment in in time.

(2) Copy-on-write mechanism: As files are modified or deleted on the original volume, the VSS utilizes a copy-on-write mechanism.  It stores the original data in the snapshot, allowing users to access the unchanged version while the new changes are written to the live volume.  The lag induced by this can be measured with the appropriate but except with the largest files or on a busy network, it’s not usually something which affects the user.

(3) Shadow copy storage: The shadow copies are stored in a separate location on the disk, typically in a hidden system folder. The storage space occupied by is system-managed by the system, older copies automatically deleted as space is demanded for newer versions.

(4) User accessibility: Users can access the shadow copies through various means, most obviously the "Previous Versions" tab in file properties or the "Previous Versions" feature in Windows Explorer. These interfaces allow users to browse and restore files from a previous point in time.

Shadow copies provided one of the first forms of dynamic file backups for most users and were a convenient form of data recovery without the need of third-party software or external devices.  At scale, similar processes are used by software by companies such as StorageCraft’s ShadowProtect which system administrators can configure in a way that the potential data-losses can be minimized to windows as short as a few minutes.  Combined with off-site backups on large capacity media, it’s still a pest practice approach to data preservation.

Lindsay Lohan's strangely neglected film Among the Shadows (Momentum Pictures, 2019) was also released in some markets as The Shadow Within and it's not known what prompted the change (although there was a film in 2007 called The Shadow Within).  Given the two titles under which the film was distributed have quite different meanings, presumably either the title is incidental to the content or equally applicable.  A dark and gloomy piece about murderous werewolves and EU politicians (two quite frightening species), perhaps both work well and no reviewer appears to have commented on the matter and given the tone of the reviews, it seems unlikely there'll be a sequel to resolve things.