Development of gravitational theory.

Something like the equivalence principle emerged in the early 17th century, when Galileo expressed experimentally that the acceleration of a test mass due to gravitation is independent of the amount of mass being accelerated.  Kepler, using Galileo's discoveries, showed knowledge of the equivalence principle by accurately describing what would occur if the moon were stopped in its orbit and dropped towards Earth. This can be deduced without knowing if or in what manner gravity decreases with distance, but requires assuming the equivalency between gravity and inertia.  The 1/54 ratio is Kepler's estimate of the Moon–Earth mass ratio, based on their diameters. The accuracy of his statement can be deduced by using Newton's inertia law F=ma and Galileo's gravitational observation that distance formula_1. Setting these accelerations equal for a mass is the equivalence principle. Noting the time to collision for each mass is the same gives Kepler's statement that D/D=M/M, without knowing the time to collision or how or if the acceleration force from gravity is a function of distance.  Newton's gravitational theory simplified and formalized Galileo's and Kepler's ideas by recognizing Kepler's "animal force or some other equivalent" beyond gravity and inertia were not needed, deducing from Kepler's planetary laws how gravity reduces with distance.  The equivalence principle was properly introduced by Albert Einstein in 1907, when he observed that the acceleration of bodies towards the center of the Earth at a rate of 1""g"" ("g" = 9.81 m/s being a standard reference of gravitational acceleration at the Earth's surface) is equivalent to the acceleration of an inertially moving body that would be observed on a rocket in free space being accelerated at a rate of 1"g". Einstein stated it thus:  That is, being on the surface of the Earth is equivalent to being inside a spaceship (far from any sources of gravity) that is being accelerated by its engines. The direction or vector of acceleration equivalence on the surface of the earth is "up" or directly opposite the center of the planet while the vector of acceleration in a spaceship is directly opposite from the mass ejected by its thrusters. From this principle, Einstein deduced that free-fall is inertial motion. Objects in free-fall do not experience being accelerated downward (e.g. toward the earth or other massive body) but rather weightlessness and no acceleration. In an inertial frame of reference bodies (and photons, or light) obey Newton's first law, moving at constant velocity in straight lines. Analogously, in a curved spacetime the world line of an inertial particle or pulse of light is "as straight as possible" (in space "and" time). Such a world line is called a geodesic and from the point of view of the inertial frame is a straight line. This is why an accelerometer in free-fall doesn't register any acceleration; there isn't any between the internal test mass and the accelerometer's body.  As an example: an inertial body moving along a geodesic through space can be trapped into an orbit around a large gravitational mass without ever experiencing acceleration. This is possible because spacetime is radically curved in close vicinity to a large gravitational mass. In such a situation the geodesic lines bend inward around the center of the mass and a free-floating (weightless) inertial body will simply follow those curved geodesics into an elliptical orbit. An accelerometer on-board would never record any acceleration.  By contrast, in Newtonian mechanics, gravity is assumed to be a force. This force draws objects having mass towards the center of any massive body. At the Earth's surface, the force of gravity is counteracted by the mechanical (physical) resistance of the Earth's surface. So in Newtonian physics, a person at rest on the surface of a (non-rotating) massive object is in an inertial frame of reference. These considerations suggest the following corollary to the equivalence principle, which Einstein formulated precisely in 1911:  Einstein also referred to two reference frames, K and K'. K is a uniform gravitational field, whereas K' has no gravitational field but is uniformly accelerated such that objects in the two frames experience identical forces:  This observation was the start of a process that culminated in general relativity. Einstein suggested that it should be elevated to the status of a general principle, which he called the "principle of equivalence" when constructing his theory of relativity:  Einstein combined (postulated) the equivalence principle with special relativity to predict that clocks run at different rates in a gravitational potential, and light rays bend in a gravitational field, even before he developed the concept of curved spacetime.  So the original equivalence principle, as described by Einstein, concluded that free-fall and inertial motion were physically equivalent. This form of the equivalence principle can be stated as follows. An observer in a windowless room cannot distinguish between being on the surface of the Earth, and being in a spaceship in deep space accelerating at 1g. This is not strictly true, because massive bodies give rise to tidal effects (caused by variations in the strength and direction of the gravitational field) which are absent from an accelerating spaceship in deep space. The room, therefore, should be small enough that tidal effects can be neglected.  Although the equivalence principle guided the development of general relativity, it is not a founding principle of relativity but rather a simple consequence of the "geometrical" nature of the theory. In general relativity, objects in free-fall follow geodesics of spacetime, and what we perceive as the force of gravity is instead a result of our being unable to follow those geodesics of spacetime, because the mechanical resistance of matter prevents us from doing so.  Since Einstein developed general relativity, there was a need to develop a framework to test the theory against other possible theories of gravity compatible with special relativity. This was developed by Robert Dicke as part of his program to test general relativity. Two new principles were suggested, the so-called Einstein equivalence principle and the strong equivalence principle, each of which assumes the weak equivalence principle as a starting point. They only differ in whether or not they apply to gravitational experiments.  Another clarification needed is that the equivalence principle assumes a constant acceleration of 1g without considering the mechanics of generating 1g. If we do consider the mechanics of it, then we must assume the aforementioned windowless room has a fixed mass. Accelerating it at 1g means there is a constant force being applied, which = m*g where m is the mass of the windowless room along with its contents (including the observer). Now, if the observer jumps inside the room, an object lying freely on the floor will decrease in weight momentarily because the acceleration is going to decrease momentarily due to the observer pushing back against the floor in order to jump. The object will then gain weight while the observer is in the air and the resulting decreased mass of the windowless room allows greater acceleration; it will lose weight again when the observer lands and pushes once more against the floor; and it will finally return to its initial weight afterwards. To make all these effects equal those we would measure on a planet producing 1g, the windowless room must be assumed to have the same mass as that planet. Additionally, the windowless room must not cause its own gravity, otherwise the scenario changes even further. These are technicalities, clearly, but practical ones if we wish the experiment to demonstrate more or less precisely the equivalence of 1g gravity and 1g acceleration.

Modern usage.

Three forms of the equivalence principle are in current use: weak (Galilean), Einsteinian, and strong.

The weak equivalence principle.

The weak equivalence principle, also known as the universality of free fall or the Galilean equivalence principle can be stated in many ways. The strong EP includes (astronomic) bodies with gravitational binding energy (e.g., 1.74 solar-mass pulsar PSR J1903+0327, 15.3% of whose separated mass is absent as gravitational binding energy). The weak EP assumes falling bodies are bound by non-gravitational forces only. Either way:  Locality eliminates measurable tidal forces originating from a radial divergent gravitational field (e.g., the Earth) upon finite sized physical bodies. The "falling" equivalence principle embraces Galileo's, Newton's, and Einstein's conceptualization. The equivalence principle does not deny the existence of measurable effects caused by a "rotating" gravitating mass (frame dragging), or bear on the measurements of light deflection and gravitational time delay made by non-local observers.

Active, passive, and inertial masses.

By definition of active and passive gravitational mass, the force on formula_2 due to the gravitational field of formula_3 is:  Likewise the force on a second object of arbitrary mass due to the gravitational field of mass is:  By definition of inertial mass:  If formula_7 and formula_8 are the same distance formula_9 from formula_10 then, by the weak equivalence principle, they fall at the same rate (i.e. their accelerations are the same)  Hence:  Therefore:  In other words, passive gravitational mass must be proportional to inertial mass for all objects.  Furthermore, by Newton's third law of motion:  must be equal and opposite to  It follows that:  In other words, passive gravitational mass must be proportional to active gravitational mass for all objects.  The dimensionless Eötvös-parameter formula_17 is the difference of the ratios of gravitational and inertial masses divided by their average for the two sets of test masses "A" and "B."

Tests of the weak equivalence principle.

Tests of the weak equivalence principle are those that verify the equivalence of gravitational mass and inertial mass. An obvious test is dropping different objects, ideally in a vacuum environment, e.g., inside the Fallturm Bremen drop tower.  See:  Experiments are still being performed at the University of Washington which have placed limits on the differential acceleration of objects towards the Earth, the Sun and towards dark matter in the galactic center. Future satellite experiments – STEP (Satellite Test of the Equivalence Principle), Galileo Galilei, and MICROSCOPE (MICROSatellite à traînée Compensée pour l'Observation du Principe d'Équivalence) – will test the weak equivalence principle in space, to much higher accuracy.  With the first successful production of antimatter, in particular anti-hydrogen, a new approach to test the weak equivalence principle has been proposed. Experiments to compare the gravitational behavior of matter and antimatter are currently being developed.  Proposals that may lead to a quantum theory of gravity such as string theory and loop quantum gravity predict violations of the weak equivalence principle because they contain many light scalar fields with long Compton wavelengths, which should generate fifth forces and variation of the fundamental constants. Heuristic arguments suggest that the magnitude of these equivalence principle violations could be in the 10 to 10 range. Currently envisioned tests of the weak equivalence principle are approaching a degree of sensitivity such that "non-discovery" of a violation would be just as profound a result as discovery of a violation. Non-discovery of equivalence principle violation in this range would suggest that gravity is so fundamentally different from other forces as to require a major reevaluation of current attempts to unify gravity with the other forces of nature. A positive detection, on the other hand, would provide a major guidepost towards unification.

The Einstein equivalence principle.

What is now called the "Einstein equivalence principle" states that the weak equivalence principle holds, and that: Here "local" has a very special meaning: not only must the experiment not look outside the laboratory, but it must also be small compared to variations in the gravitational field, tidal forces, so that the entire laboratory is freely falling. It also implies the absence of interactions with "external" fields "other than the gravitational field".  The principle of relativity implies that the outcome of local experiments must be independent of the velocity of the apparatus, so the most important consequence of this principle is the Copernican idea that dimensionless physical values such as the fine-structure constant and electron-to-proton mass ratio must not depend on where in space or time we measure them. Many physicists believe that any Lorentz invariant theory that satisfies the weak equivalence principle also satisfies the Einstein equivalence principle.  "Schiff's conjecture" suggests that the weak equivalence principle implies the Einstein equivalence principle, but it has not been proven. Nonetheless, the two principles are tested with very different kinds of experiments. The Einstein equivalence principle has been criticized as imprecise, because there is no universally accepted way to distinguish gravitational from non-gravitational experiments (see for instance Hadley and Durand).

Tests of the Einstein equivalence principle.

In addition to the tests of the weak equivalence principle, the Einstein equivalence principle can be tested by searching for variation of dimensionless constants and mass ratios. The present best limits on the variation of the fundamental constants have mainly been set by studying the naturally occurring Oklo natural nuclear fission reactor, where nuclear reactions similar to ones we observe today have been shown to have occurred underground approximately two billion years ago. These reactions are extremely sensitive to the values of the fundamental constants.  There have been a number of controversial attempts to constrain the variation of the strong interaction constant. There have been several suggestions that "constants" do vary on cosmological scales. The best known is the reported detection of variation (at the 10 level) of the fine-structure constant from measurements of distant quasars, see Webb et al. Other researchers dispute these findings. Other tests of the Einstein equivalence principle are gravitational redshift experiments, such as the Pound–Rebka experiment which test the position independence of experiments.

The strong equivalence principle.

The strong equivalence principle suggests the laws of gravitation are independent of velocity and location. In particular, and The first part is a version of the weak equivalence principle that applies to objects that exert a gravitational force on themselves, such as stars, planets, black holes or Cavendish experiments. The second part is the Einstein equivalence principle (with the same definition of "local"), restated to allow gravitational experiments and self-gravitating bodies. The freely-falling object or laboratory, however, must still be small, so that tidal forces may be neglected (hence "local experiment").  This is the only form of the equivalence principle that applies to self-gravitating objects (such as stars), which have substantial internal gravitational interactions. It requires that the gravitational constant be the same everywhere in the universe and is incompatible with a fifth force. It is much more restrictive than the Einstein equivalence principle.  The strong equivalence principle suggests that gravity is entirely geometrical by nature (that is, the metric alone determines the effect of gravity) and does not have any extra fields associated with it. If an observer measures a patch of space to be flat, then the strong equivalence principle suggests that it is absolutely equivalent to any other patch of flat space elsewhere in the universe. Einstein's theory of general relativity (including the cosmological constant) is thought to be the only theory of gravity that satisfies the strong equivalence principle. A number of alternative theories, such as Brans–Dicke theory, satisfy only the Einstein equivalence principle.

Tests of the strong equivalence principle.

The strong equivalence principle can be tested by searching for a variation of Newton's gravitational constant "G" over the life of the universe, or equivalently, variation in the masses of the fundamental particles. A number of independent constraints, from orbits in the solar system and studies of Big Bang nucleosynthesis have shown that "G" cannot have varied by more than 10%.  Thus, the strong equivalence principle can be tested by searching for fifth forces (deviations from the gravitational force-law predicted by general relativity). These experiments typically look for failures of the inverse-square law (specifically Yukawa forces or failures of Birkhoff's theorem) behavior of gravity in the laboratory. The most accurate tests over short distances have been performed by the Eöt–Wash group. A future satellite experiment, SEE (Satellite Energy Exchange), will search for fifth forces in space and should be able to further constrain violations of the strong equivalence principle. Other limits, looking for much longer-range forces, have been placed by searching for the Nordtvedt effect, a "polarization" of solar system orbits that would be caused by gravitational self-energy accelerating at a different rate from normal matter. This effect has been sensitively tested by the Lunar Laser Ranging Experiment. Other tests include studying the deflection of radiation from distant radio sources by the sun, which can be accurately measured by very long baseline interferometry. Another sensitive test comes from measurements of the frequency shift of signals to and from the Cassini spacecraft. Together, these measurements have put tight limits on Brans–Dicke theory and other alternative theories of gravity.  In 2014, astronomers discovered a stellar triple system including a millisecond pulsar PSR J0337+1715 and two white dwarfs orbiting it. The system provided them a chance to test the strong equivalence principle in a strong gravitational field with high accuracy.

Challenges.

One challenge to the equivalence principle is the Brans–Dicke theory. Self-creation cosmology is a modification of the Brans–Dicke theory. The Fredkin Finite Nature Hypothesis is an even more radical challenge to the equivalence principle and has even fewer supporters.  In August 2010, researchers from the University of New South Wales, Swinburne University of Technology, and Cambridge University published a paper titled "Evidence for spatial variation of the fine structure constant", whose tentative conclusion is that, "qualitatively, [the] results suggest a violation of the Einstein Equivalence Principle, and could infer a very large or infinite universe, within which our 'local' Hubble volume represents a tiny fraction."

Explanations.

Dutch physicist and string theorist Erik Verlinde has generated a self-contained, logical derivation of the equivalence principle based on the starting assumption of a holographic universe. Given this situation, gravity would not be a true fundamental force as is currently thought but instead an "emergent property" related to entropy. Verlinde's entropic gravity theory apparently leads naturally to the correct observed strength of dark energy; previous failures to explain its incredibly small magnitude have been called by such people as cosmologist Michael Turner (who is credited as having coined the term "dark energy") as "the greatest embarrassment in the history of theoretical physics". These ideas are far from settled and still very controversial.

In the theory of general relativity, the equivalence principle is the equivalence of gravitational and inertial mass, and Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is the same as the "pseudo-force" experienced by an observer in a non-inertial (accelerated) frame of reference.

Das Äquivalenzprinzip der Physik drückt aus, dass die schwere und die träge Masse eines Körpers zwei äquivalente Größen sind. Diese Formulierung gibt in moderner Ausdrucksweise die frühen Feststellungen von Galileo Galilei und Isaac Newton wieder, dass beim freien Fall alle Körper gleich beschleunigt werden bzw. dass alle Gravitationswirkungen proportional zur Masse der beteiligten Körper sind. Albert Einstein erkannte ab 1907 hierin ein mögliches Grundprinzip einer Theorie der Gravitation, das ihn schließlich zur allgemeinen Relativitätstheorie leitete.


Composition history.

Sources.

The libretto of "Tannhäuser" combines mythological elements characteristic of German "Romantische Oper" (Romantic opera) and the medieval setting typical of many French Grand Operas. Wagner brings these two together by constructing a plot involving the 14th-century Minnesingers and the myth of Venus and her subterranean realm of Venusberg. Both the historical and the mythological are united in Tannhäuser's personality; although he is a historical poet composer, little is known about him other than myths that surround him.  Wagner wove a variety of sources into the opera narrative. According to his autobiography, he was inspired by finding the story in "a "Volksbuch" (popular book) about the Venusberg", which he claimed "fell into his hands", although he admits knowing of the story from the "Phantasus" of Ludwig Tieck and E. T. A. Hoffmann's story, "Der Kampf der Sänger" (The Singers' Contest). Tieck's tale, which names the hero "Tannenhäuser", tells of the minnesinger-knight's amorous adventures in the Venusberg, his travels to Rome as a Pilgrim, and his repudiation by the pope. To this Wagner added material from Hoffmann's story, from "Serapions-Brüder" (1819), describing a song contest at the Wartburg castle, a castle which featured prominently in Thuringian history. Heinrich Heine had provided Wagner with the inspiration for "Der fliegende Holländer" and Wagner again drew on Heine for Tannhäuser. In Heine's sardonic essay "Elementargeister" (Elemental spirits), there appears a poem about Tannhäuser and the lure of the grotto of Venus, published in 1837 in the third volume of "Der Salon". Other possible sources include Friedrich de la Motte Fouqué's play "Der Sängerkrieg auf der Wartburg" and Eichendorff's "Das Marmorbild" (The Marble Statue, 1819).  The legend of Tannhäuser, the amorous crusading Franconian knight, and that of the song contest on the Wartburg (which did not involve Tannhäuser, but the semi-mythical minnesinger Heinrich von Ofterdingen), came from quite separate traditions. Ludwig Bechstein wove together the two legends in the first volume of his collection of Thuringian legends, "Der Sagenschatz und die Sagenkreise des Thüringerlandes" (A treasury of the tales of Thuringian legends and legend cycles, 1835), which was probably the "Volksbuch" to which Wagner refers to in his autobiography. Wagner also knew of the work of another contemporary, Christian Theodor Ludwig Lucas, whose "Über den Krieg von Wartburg" of 1838 also conflated the two legends. This confusion (which explains why Tannhäuser is referred to as 'Heinrich' in the opera) does not fit with the historical timeline of the events in the opera, since the Singers' Contest involving von Ofterdingen is said to have taken place around 1207, while Tannhäuser's poetry appeared much later (1245–1265). The sources used by Wagner therefore reflected a nineteenth century romantic view of the medieval period, with concerns about artistic freedom and the constraints of organised religion typical of the period of Romanticism.  During Wagner's first stay in Paris (1839–1842) he read a paper by Ludwig Lucas on the "Sängerkrieg" which sparked his imagination, and encouraged him to return to Germany, which he reached on 7 April 1842. Having crossed the Rhine, the Wagners drove towards Thuringia, and saw the early rays of sun striking the Wartburg; Wagner immediately began to sketch the scenery that would become the stage sets. Wagner wrote the prose draft of "Tannhäuser" between June and July 1842 and the libretto in April 1843.

Composition.

Wagner began composing the music during a vacation in Teplitz in the summer of 1843 and completed the full score on 13 April 1845; the opera's famous overture, often played separately as a concert piece, was written last. While composing the music for the Venusberg grotto, Wagner grew so impassioned that he made himself ill; in his autobiography, he wrote, "With much pain and toil I sketched the first outlines of my music for the "Venusberg"... Meanwhile I was very much troubled by excitability and rushes of blood to the brain. I imagined I was ill and lay for whole days in bed..." The instrumentation also shows signs of borrowing from French operatic style. The score includes parts for on-stage brass; however, rather than using French brass instruments, Wagner uses twelve German waldhorns. Wagner also makes use of the harp, another commonplace of French opera. Wagner made a number of revisions of the opera throughout his life, and was still unsatisfied with its format when he died. The most significant revision was made for the opera's premiere in Paris in 1861.

Performance history.

Dresden version (1845).

The first performance was given in the "Königliches Hoftheater" (Royal Theater) in Dresden on 19 October 1845. The composer Ferdinand Hiller, at that time a friend of the composer, assisted in the musical preparations for the production. The part of Elisabeth was sung by Wagner's niece Johanna Wagner. Wagner had intended to premiere the opera on 13 October, Johanna's 19th birthday, but she was ill, so it was postponed by six days. Venus was created by Wilhelmine Schröder-Devrient, and the title role was taken by Josef Tichatschek. The performance was conducted by the composer. "Tannhäuser" was not the success that "Rienzi" had been, and Wagner almost immediately set to modifying the ending, adjusting the score through 1846 and 1847. For the first Dresden revival (1847) he clarified the representation of Venus's temptation of Tannhäuser in the final act, and adding vocal presentation of the pilgrim's chorus in this act (where it had previously been represented by orchestra alone). This version of the opera, as revised for publication in 1860, is generally known as the "Dresden" version. After Franz Liszt produced the opera at Weimar Court Theatre in 1849, there were further performances between 1852 and 1856 in (amongst other locations) Schwerin, Kassel, Posen, Wiesbaden, Hanover, Munich and Berlin.  The Dresden version was also used for initial productions outside Germany, notably at Riga on 18 January 1853; at Tallinn on 10 January 1854; at Prague on 25 November 1854 at Theatre of the Estates; at New York City on 4 April 1859 at the Stadt Theatre; and in London on 6 May 1876 at the Royal Opera House, Covent Garden (when it was sung in Italian).

Paris version (1861).

Wagner substantially amended the opera for a special 1861 performance by the Paris Opéra. This had been requested by Emperor Napoleon III at the suggestion of Princess Pauline von Metternich, wife of the Austrian ambassador to France. This revision forms the basis of what is now known as the "Paris version" of "Tannhäuser". The venue meant that the composer had to insert a ballet into the score, according to the traditions of the house. Wagner agreed to this condition since he believed that a success at the Opéra represented his most significant opportunity to re-establish himself following his exile from Germany. However, rather than put the ballet in its traditional place in Act II, he chose to place it in Act I, in the form of a bacchanale, where it could make dramatic sense by representing the sensual world of Venus's realm. There were further extensive changes. The text was translated into French (by Charles-Louis-Etienne Nuitter and others). Venus, a role that in the Dresden version was considered a soprano, was rewritten as for mezzo-soprano. Venus' aria "Geliebter, komm!" was transposed down by a semitone, and its latter part was completely rewritten. A solo for Walther was removed from Act 2. Extra lines for Venus following Tannhäuser's "Hymn to Love" were added. The orchestral introduction to Act 3 was shortened. The end of the opera was reworked to include Venus on stage, where before the audience only heard the Venus motif, in an attempt to clarify the action.  "Tannhäuser"s first performance in Paris was given on 13 March 1861 at the Salle Le Peletier of the Paris Opéra. The composer had been closely involved in its preparation and there had been 164 rehearsals. The costumes were designed by Alfred Albert, the sets by Charles-Antoine Cambon and Joseph Thierry (Act I, scene 1), Édouard Desplechin (Act I, scene 2 and Act III), and Joseph Nolau and Auguste Alfred Rubé (Act II).  At the first performance the opera was initially well-received, with disturbances including whistling and cat-calls beginning to appear in Act II, and becoming prominent by the end of the third act. For the second performance much of the new ballet music was removed, together with some actions that had specifically provoked mockery, such as the piping of the shepherd in Act I. At this performance however the audience disturbances were increased. This was partly due to members of the wealthy and aristocratic Jockey Club, who objected to the ballet coming in Act I, since this meant they would have to be present from the beginning of the performance (disrupting their dining schedule). It was alleged that they distributed whistles to the audience. A further incentive to disruption was the unpopularity of Princess von Metternich and of her native country of Austria. At the third performance on 24 March (which Wagner did not attend) uproar caused several interruptions of up to fifteen minutes at a time. As a consequence, Wagner withdrew the opera after the third performance. This marked the end to Wagner's hopes of establishing himself in Paris.  The first performance outside France of the "Paris" version was given in Bologna on 7 November 1872 at the Teatro Comunale, (the first performance of the opera in Italy). The American and British premieres of this version were respectively in New York at the Metropolitan Opera on 30 January 1889, and at London's Royal Opera House on 15 July 1895.

Vienna version (1875).

A few further changes to "Tannhäuser" were made for an 1875 performance of the opera in Vienna, the last production carried out under Wagner's own supervision. These included linking the end of the overture to the start of the opera proper. The 1875 Vienna version is that normally used in modern productions of the "Paris" version, often with the reinstatement of Walther's Act 2 solo. Wagner remained unsatisfied with the opera. His wife Cosima noted in her diary on 23 January 1883 (three weeks before he died) "He says he still owes the world "Tannhäuser"."

Roles.

Although the libretto and the score always use the single name "Tannhäuser" in stage directions involving the title character or in indicating which passages are sung by him, that name never appears as part of the lyrics. Rather, each character who addresses Tannhäuser by name uses his given name "Heinrich" (Heinrich von Ofterdingen).  The distinct character Heinrich der Schreiber sings many melodies distinct from all other named characters, and occasionally unique lyrics. However, in the libretto he finds individual mention only in the list of characters, with the ensemble numbers that include him being labelled for the "Ritter" (i.e., "knights", referring to the "Minnesinger", who all share knightly rank). The score in the Schirmer edition labels his melody line simply "Schreiber".

Instrumentation.

"Tannhäuser" is scored for the following instruments:  "on-stage"

Synopsis.

Background.

In Eisenach, Germany, in the early 13th century, the landgraves of the Thuringian Valley ruled the area of Germany around the Wartburg. They were great patrons of the arts, particularly music and poetry, holding contests between the minnesingers at the Wartburg. Across the valley towered the Venusberg, in whose interior, according to legend, dwelt Holda, the Goddess of Spring. In time, Holda became identified with Venus, the pagan Goddess of Love, whose grotto was the home of sirens and nymphs. It was said that the Goddess would lure the Wartburg minnesinger-knights to her lair where her beauty would captivate them. The minnesinger-knight Heinrich von Ofterdingen, known as Tannhäuser, left the court of the Landgrave of Thuringia a year ago after a disagreement with his fellow knights. Since then he has been held as a willing captive through his love for Venus, in her grotto in the Venusberg.

Overture.

The substantial overture commences with the theme of the 'Pilgrim's Chorus' from Act 3, Scene 1, and also includes elements of the 'Venusberg' music from Act 1, Scene 1. The overture is frequently performed as a separate item in orchestral concerts, the first such performance having been given by Felix Mendelssohn conducting the Leipzig Gewandhaus Orchestra in February 1846. Wagner later gave the opinion that perhaps it would be better to cut the overture at opera performances to the Pilgrim's Chorus alone – "the remainder – in the fortunate event of its being understood – is, as a prelude to the drama, too much; in the opposite event, too little." In the original, "Dresden" version, the overture comes to a traditional concert close (the version heard in concert performances). For the "Paris" version the music leads directly into the first scene, without pausing.

Act 1.

"The Venusberg, (the Hörselberg of "Frau Holda" in Thuringia, in the vicinity of Eisenach)", and a valley between the Venusberg and Wartburg  Scene 1. Wagner's stage directions state: "The stage represents the interior of the Venusberg...In the distant background is a bluish lake; in it one sees the bathing figures of naiads; on its elevated banks are sirens. In the extreme left foreground lies Venus bearing the head of the half kneeling Tannhäuser in her lap. The whole cave is illuminated by rosy light. – A group of dancing nymphs appears, joined gradually by members of loving couples from the cave. – A train of Bacchantes comes from the background in wild dance... – The ever-wilder dance answers as in echo the Chorus of Sirens": "Naht euch dem Strande" (Come to the shore). In the "Paris" version this orgiastic ballet is greatly extended.  Scene 2. Following the orgy of the ballet, Tannhäuser's desires are finally satiated, and he longs for freedom, spring and the sound of church bells. He takes up his harp and pays homage to the goddess in a passionate love song, "Dir töne Lob!" (Let your praises be heard), which he ends with an earnest plea to be allowed to depart, "Aus deinem Reiche, muss ich fliehn! O Königin! Göttin! Lass mich ziehn!" (From your kingdom must I flee! O Queen! O Goddess, set me free). Surprised, Venus offers him further charms, but eventually his repeated pleas arouse her fury and she curses his desire for salvation. (In the "Paris" version Venus's inveighing against Tannhäuser is significantly expanded). Eventually Tannhäuser declares: "Mein Heil ruht in Maria" (My salvation rests in Mary). These words break the unholy spell. Venus and the Venusberg disappear.  Scene 3. According to Wagner's stage directions, "Tannhäuser...finds himself a beautiful valley... To the left one sees the Hörselberg. To the right...a mountain path from the direction of the Wartburg...; in the foreground, led to by a low promontory, an image of the Virgin Mary – From above left one hears the ringing of herder’s bells; on a high projection sits a young shepherd with pipes facing the valley". It is May. The shepherd sings an ode to the pagan goddess Holda, "Frau Holda kam aus dem Berg hervor" (Lady Holda, come forth from the hill). A hymn "Zu dir wall ich, mein Jesus Christ" (To thee I turn, my Jesus Christ) can be heard, as Pilgrims are seen approaching from the Wartburg, and the shepherd stops playing. The pilgrims pass Tannhäuser as he stands motionless, and then, praising God, ("Allmächt'ger, dir sei Preis!" (Almighty God, to you be praise!)) he sinks to his knees, overcome with gratitude. At that moment the sound of hunting-horns can be heard, drawing ever nearer.  Scene 4. The Landgrave's hunting party appears. The minnesingers (Wolfram, Walther, Biterolf, Reinmar, and Heinrich) recognise Tannhäuser, still deep in prayer, and greet him ("Heinrich! Heinrich! Seh ich recht?" (Heinrich! Heinrich! Do I see right?)) cautiously, recalling past feuds. They question him about his recent whereabouts, to which he gives vague answers. The minnesingers urge Tannhäuser to rejoin them, which he declines until Wolfram mentions Elisabeth, the Landgrave's niece, "Bleib bei Elisabeth!" (Stay, for Elisabeth!). Tannhäuser is visibly moved, "Elisabeth! O Macht des Himmels, rufst du den süsssen Namen mir?" (Elisabeth! O might of heaven, is it you that wakes me with that sweet name?). The minnesingers explain to Tannhäuser how he had enchanted Elisabeth, but when he had left she withdrew from their company and lost interest in music, expressing the hope that his return will also bring her back, "Auf's Neue leuchte uns ihr Stern!" (Let her star once more shine upon us). Tannhäuser begs them to lead him to her, "Zu ihr! Zu ihr!" (To her! To her!). The rest of the hunting party gathers, blowing horns.

Act 2.

"The minnesingers' hall in the Wartburg castle"  Introduction – Scene 1. Elisabeth enters, joyfully. She sings, to the hall, of how she has been beset by sadness since Tannhäuser's departure but now lives in hope that his songs will revive both of them, "Dich, teure Halle, grüss ich wieder" (Dear hall, I greet thee once again). Wolfram leads Tannhäuser into the hall.  Scene 2. Tannhäuser flings himself at Elisabeth's feet. He exclaims "O Fürstin!" (O Princess!). At first, seemingly confused, she questions him about where he has been, which he avoids answering. She then greets him joyfully ("Ich preise dieses Wunder aus meines Herzens Tiefe!" (I praise this miracle from my heart's depths!)), and they join in a duet, "Gepriesen sei die Stunde" (Praise be to this hour). Tannhäuser then leaves with Wolfram.  Scene 3. The Landgrave enters, and he and Elisabeth embrace. The Landgrave sings of his joy, "Dich treff ich hier in dieser Halle" (Do I find you in this hall) at her recovery and announces the upcoming song contest, at which she will preside, "dass du des Festes Fürstin seist" (that you will be the Princess of the Festival).  Scene 4 and "Sängerkrieg" (Song Contest). Elisabeth and the Landgrave watch the guests arrive. The guests assemble greeting the Landgrave and singing "Freudig begrüssen wir edle Halle" (With joy we greet the noble hall), take their places in a semicircle, with Elisabeth and the Landgrave in the seats of honour in the foreground. The Landgrave announces the contest and the theme, which shall be "Könnt ihr der Liebe Wesen mir ergründen?" (Can you explain the nature of Love?), and that the prize will be whatever the winner asks of Elisabeth. The knights place their names in a cup from which Elisabeth draws the first singer, Wolfram. Wolfram sings a trite song of courtly love and is applauded, but Tannhäuser chides him for his lack of passion. There is consternation, and once again Elisabeth appears confused, torn between rapture and anxiety. Biterolf accuses him of blasphemy and speaks of "Frauenehr und hohe Tugend" (women's virtue and honour). The knights draw their swords as Tannhäuser mocks Biterolf, but the Landgrave intervenes to restore order. However, Tannhäuser, as if in a trance, rises to his feet and sings a song of ecstatic love to Venus, "Dir Göttin der Liebe, soll mein Lied ertönen" (To thee, Goddess of Love, will my song be raised). There is general horror as it is realised he has been in the Venusberg; the women, apart from Elisabeth, flee. She appears pale and shocked, while the knights and the Landgrave gather together and condemn Tannhäuser to death. Only Elisabeth, shielding him with her body, saves him, "Haltet ein!" (Stop!). She states that God's will is that a sinner shall achieve salvation through atonement. Tannhäuser collapses as all hail Elisabeth as an angel, "Ein Engel stieg aus lichtem Äther" (An angel comes to us from the realm of light). He promises to seek atonement, the Landgrave exiles him and orders him to join another younger band of pilgrims then assembling. All depart, crying "Nach Rom!" (To Rome!).  In the "Paris" version, the song contest is somewhat shortened, possibly because of the lack of suitable soloists for the Paris production.

Act 3.

"The valley of the Wartburg, in autumn. Elisabeth is kneeling, praying before the Virgin as Wolfram comes down the path and notices her"  Scene 1. Orchestral music describes the pilgrimage of Tannhäuser. It is evening. Wolfram muses on Elisabeth's sorrow during Tannhäuser's second absence, "Wohl wusst' ich hier sie im Gebet zu finden" (I knew well I might find her here in prayer) and her longing for the return of the pilgrims, and expresses concerns that he may not have been absolved. As he does so he hears a pilgrims' prayer in the distance, "Beglückt darf nun dich, O Heimat, ich schauen" (Joyfully now my homeland I behold). Elisabeth rises and she and Wolfram listen to the hymn, watching the pilgrims approach and pass by. She anxiously searches the procession, but in vain, realising sorrowfully he is not amongst them, "Er kehret nicht züruck!" (He has not returned). She again kneels with a prayer to the Virgin that appears to foretell her death, "Allmächt'ge Jungfrau! Hör mein Flehen" (Almighty Virgin, hear my plea!). On rising she sees Wolfram but motions him not to speak. He offers to escort her back to the Wartburg, but she again motions him to be still, and gestures that she is grateful for his devotion but her path leads to heaven. She slowly makes her way up the path alone.  Scene 2. Wolfram, left alone as darkness draws on and the stars appear, begins to play and sings a hymn to the evening star that also hints at Elisabeth's approaching death, "Wie Todesahnung Dämmrung deckt die Lande...O du mein holder Abendstern" (Like a premonition of death the twilight shrouds the earth... O thou my fair evening star).  Scene 3. It is now night. Tannhäuser appears, ragged, pale and haggard, walking feebly leaning on his staff. Wolfram suddenly recognises Tannhäuser, and startled challenges him, since he is exiled. To Wolfram's horror, Tannhäuser explains he is once again seeking the company of Venus. Wolfram tries to restrain him, at the same time expressing compassion and begging him to tell the story of his pilgrimage. Tannhäuser urges Wolfram to listen to his story, "Nun denn, hör an! Du, Wolfram, du sollst es erfahren" (Now then, listen! You, Wolfram, shall learn all that has passed). Tannhäuser sings of his penitence and suffering, all the time thinking of Elisabeth's gesture and pain, "Inbrunst im Herzen, wie kein Büsser noch" (With a flame in my heart, such as no penitent has known). He explains how he reached Rome, and the "Heiligtumes Schwelle" (Holy shrine), and witnessed thousands of pilgrims being absolved. Finally he approaches "ihn, durch den sich Gott verkündigt'" (he, through whom God speaks) and tells his story. However, rather than finding absolution, he is cursed, "bist nun ewig du verdammt!" (you are forever damned!), and is told by the pope that "Wie dieser Stab in meiner Hand, nie mehr sich schmückt mit frischem Grün, kann aus der Hölle heissem Brand, Erlösung nimmer dir erblühn!" (As this staff in my hand, no more shall bear fresh leaves, from the hot fires of hell, salvation never shall bloom for thee). Whereupon, absolutely crushed, he fled, seeking his former source of bliss.  Having completed his tale, Tannhäuser calls out to Venus to take him back, "Zu dir, Frau Venus, kehr ich wieder" (To you, Lady Venus, I return). The two men struggle as a faint image of dancing becomes apparent. As Tannhäuser repeatedly calls on Venus, she suddenly appears and welcomes him back, "Willkommen, ungetreuer Mann!" (Welcome, faithless man!). As Venus continues to beckon, "Zu mir! Zu mir!" (To me!, To me!), in desperation, Wolfram suddenly remembers there is one word that can change Tannhäuser's heart, and exclaims "Elisabeth!" Tannhäuser, as if frozen in time, repeats the name. As he does so, torches are seen, and a funeral hymn is heard approaching, "Der Seele Heil, die nun entflohn" (Hail, the soul that now is flown). Wolfram realises it must be Elisabeth's body that is being borne, and that in her death lies Tannhäuser's redemption, "Heinrich, du bist erlöst!" (Heinrich, you are saved). Venus cries out, "Weh! Mir verloren" (Alas! Lost to me!) and vanishes with her kingdom. As dawn breaks the procession appears bearing Elisabeth's body on a bier. Wolfram beckons to them to set it down, and as Tannhäuser bends over the body uttering, "Heilige Elisabeth, bitte für mich!" (Holy Elisabeth!, pray for me!) he dies. As the growing light bathes the scene the younger pilgrims arrive bearing the pope's staff sprouting new leaves, and proclaiming a miracle, "Heil! Heil! Der Gnade Wunder Heil!" (Hail!, Hail! To this miracle of grace, Hail!). All then sing "Der Gnade Heil ist dem Büsser beschieden, er geht nun ein in der Seligen Frieden!" (The Holy Grace of God is to the penitent given, who now enters into the joy of Heaven!).

After Wagner.

Productions.

Wagner died in 1883. The first production of the opera at Wagner's Bayreuth Festspielhaus (originally constructed for the performance of his Ring Cycle), was undertaken under the supervision of Cosima in 1891, and adhered closely to the 'Vienna' version. Later performances at Bayreuth included one conducted by Richard Strauss (1894), and one where the Bacchanal was choreographed by Isadora Duncan (1904). Duncan envisaged the Bacchanal as a fantasy of Tannhäuser's fevered brain, as Wagner had written to Mathilde Wesendonck in 1860. Arturo Toscanini conducted the opera at Bayreuth in the 1930/31 season.  In the words of the Wagner scholar Thomas S. Grey, "The Bacchanal remained a defining focus of many...productions, as a proving ground for changing conceptions of the psychosexual symbolism of the Venusberg." Productions including those of Götz Friedrich at Bayreuth (1972) and Otto Schenk at the Metropolitan Opera, New York, (1977) "routinely offer quantities of simulated copulation and post-coital langour, for which the Paris score offers ample encouragement". A Munich production (1994) included as part of Tannhäuser's fantasies "creatures out of Hieronymus Bosch crawl[ing] around the oblivious protagonist".  The Operabase website indicates that in the two calendar years 2014/2015, there were 163 performances of 41 productions of "Tannhäuser" in 30 cities throughout the world.

Literature.

Many scholars and writers on opera have advanced theories to explain the motives and behaviour of the characters, including Jungian psychoanalysis, in particular as regards Tannhäuser's apparently self-destructive behaviour. In 2014 an analysis suggested that his apparently inconsistent behaviour, when analysed by game theory, is actually consistent with a redemption strategy. Only by public disclosure can Tannhäuser force a resolution of his inner conflict.

References.

Citations Sources

Tannhäuser (; full title Tannhäuser und der Sängerkrieg auf Wartburg, "Tannhäuser and the Minnesingers' Contest at Wartburg") is an 1845 opera in three acts, music and text by Richard Wagner, (WWV 70 in the catalogue of the composer's works) based on two German legends: Tannhäuser, the mythologized medieval German Minnesänger and poet, and the tale of the Wartburg Song Contest. The story centers on the struggle between sacred and profane love, and redemption through love, a theme running through much of Wagner's mature work.

Tannhäuser und der Sängerkrieg auf Wartburg ist eine romantische Oper in drei Akten von Richard Wagner, welche auf der traditionellen Volksballade "Tannhauser" und dem Sängerkrieg auf der Wartburg aufbaut. Die Oper thematisiert den Zwiespalt zwischen heiliger und profaner Liebe und die Erlösung durch Liebe – ein Leitthema, welches sich auch durch viele von Wagners späten Werken zieht.


Steps.

Elisabeth Kübler-Ross has developed a well known model, not yet scientifically proven, the subject of many highly contested transpositions and adaptations. It is a theoretical cycle consisting of five steps:  The above five phases can be linear but often a mourner can flip back before starting to move forward. A good way to pass through grief is to understand what has happened and share the feelings and emotions with relatives or people who also are grieving. These steps do not necessarily follow each other. It is not an inevitable process.  Mourning is a personal and collective response which can vary depending on feelings and contexts. It starts with denial and ends with acceptance.  Grief can be defined as the period following the death of someone close. This is both psychological and social:  Death can be a release in the case of a tyrannical person or when death terminates a long, painful illness. However, this release may add remorse and guilt for the mourner.

Social customs and dress.

Africa.

Ethiopia.

In Ethiopia, an "Edir" (var. "eddir", "idir") is a traditional community organization whose members assist each other during the mourning process. Members make monthly financial contributions forming the Edir's fund. They are entitled to receive a certain sum of money from this fund to help cover funeral and other expenses associated with deaths. Additionally, Edir members comfort the mourners: female members take turns doing housework, such as preparing food for the mourning family, while male members usually take the responsibility to arrange the funeral and erect a temporary tent to shelter guests who come to visit the mourning family. Edir members are required to stay with the mourning family and comfort them for three full days.

Asia.

East Asia.

White is the traditional color of mourning in Chinese culture, with white clothes and hats formerly having been associated with death. In imperial China, Confucian mourning obligations required even the emperor to retire from public affairs upon the death of a parent. The traditional period of mourning was nominally 3 years, but usually 25–27 lunar months in practice and even shorter in the case of necessary officers. (The emperor, for example, typically remained in seclusion only 27 days.)  The Japanese term for mourning dress is "mofuku" (喪服). The term refers to either primarily black Western-style formal wear or to black traditional Japanese clothing worn at funerals and Buddhist memorial services. Other colors, particularly reds and bright shades, are considered inappropriate for mourning dress. If wearing Western clothes, women may wear a single strand of white pearls. Japanese-style mourning dress for women consists of a five-crested plain black silk kimono, black obi and black accessories worn over white undergarments, black sandals and white split-toe socks. Men's mourning dress consists of clothing worn on extremely formal occasions: a plain black silk five-crested kimono and black and white or gray and white striped hakama trousers over white undergarments, black crested haori jacket with a white closure, white or black zori and white tabi. It is customary for Japanese-style mourning dress to be worn only by the immediate family and very close friends of the deceased; other attendees wear Western-style mourning dress or subdued Western or Japanese formal clothes.  In Thailand people will wear black when attending a funeral. Black is considered the mourning color, although historically it was white. Widows may wear purple when mourning the death of their spouse.  The Filipino practices for mourning have influences from Chinese, Japanese and folk Catholic beliefs. People may wear white or black. The color red is frowned upon in the time of mourning, as it is believed that those who wear red within 9–40 days will die or suffer illness. The consumption of chicken during the wake and funeral is believed to bring death among the relatives. There is an initial nine-day mourning practice called "Pasiyam" when a novena is to be prayed by those who are mourning. During those days the spirit of the deceased is believed to be roaming. 40 days is a Catholic practice of commemorating the dead after 40 days from their death date. A Mass and a small feast are held to commemorate the dead during the 40-day period, with the 40th day as their judgment day. The immediate family wear black. The first anniversary of the death is celebrated by a feast, which signals the end of the mourning period.

West Asia.

In the Assyrian tradition, just after a person passes way, the mourning family host guests in an open house style. Only bitter coffee and tea are served, showcasing the sorrowful state of the family. On the funeral day, a memorial mass is held in the church. At the graveyard, the people gather and burn incense around the grave as clergy chant hymns in the Syriac language. The closest female relatives traditionally bewail or lament in a public display of grief as the casket descends. A few others may sing a dirge or a sentimental threnody. During all these occasions, everyone is expected to dress completely in black. Following the burial, everyone returns to the church hall for afternoon lunch and eulogy. At the hall, the closest relatives sit on a long table facing the guests as many people walk by and offer their condolences. On the third day, mourners customarily visit the grave site with a pastor to burn incense, symbolising Jesus’ triumph over death on the third day. This is also done 40 days after the funeral (representing Jesus ascending to heaven), and one year later to conclude the mourning period. Mourners wear only black until the 40 day mark and typically do not dance or celebrate any major events for one year.

Europe.

Continental Europe.

The custom of wearing unadorned black clothing for mourning dates back at least to the Roman Empire, when the "toga pulla", made of dark-colored wool, was worn during mourning.  Through the Middle Ages and Renaissance, distinctive mourning was worn for general as well as personal loss; after the St. Bartholomew's Day Massacre of Huguenots in France, Elizabeth I of England and her court are said to have dressed in full mourning to receive the French Ambassador.  Women in mourning and widows wore distinctive black caps and veils, generally in a conservative version of the current fashion.  In areas of Russia, the Czech Republic, Slovakia, Greece, Mexico, Portugal, and Spain, widows wear black for the rest of their lives. The immediate family members of the deceased wear black for an extended time. Since the 1870s, mourning practices for some cultures, even those who have emigrated to the United States, are to wear black for at least two years, though lifelong black for widows remains in Europe.  In Belgium the Court went in public mourning after publication in the Moniteur Belge. In 1924 the court went in mourning after the death of Marie-Adélaïde, Grand Duchess of Luxembourg, (10 days); The duke of Montpensier (5 days) and a full month for the death of Princess Louise of Belgium.

White mourning.

The color of deepest mourning among medieval European queens was white. In 1393, Parisians were treated to the unusual spectacle of a royal funeral carried out in white, for Leo V, King of Armenia, who died in exile. This royal tradition survived in Spain until the end of the 15th century. In 1934, Queen Wilhelmina of the Netherlands reintroduced white mourning after the death of her husband Prince Henry. It has remained a tradition in the Dutch royal family. In 2004, the four daughters of Queen Juliana of the Netherlands all wore white to their mother's funeral. In 1993, the Spanish-born Queen Fabiola introduced it in Belgium for the funeral of her husband, King Baudouin of Belgium. The custom for the Queens of France to wear [white mourning] was the origin of the White Wardrobe created in 1938 by Norman Hartnell for Queen Elizabeth (later called Queen Mother). She was required to make a State visit to France while in mourning for her mother.

United Kingdom.

Today, no special dress or behaviour is obligatory for those in mourning in the general population, although ethnic and religious faiths have specific rituals, and black is typically worn at funerals. Traditionally, however, there were strict social rules to be observed.

Georgian and Victorian Eras.

By the 19th century, mourning behaviour in England had developed into a complex set of rules, particularly among the upper classes. For women, the customs involved wearing heavy, concealing, black clothing, and the use of heavy veils of black crêpe. The entire ensemble was colloquially known as "widow's weeds" (from the Old English, meaning "garment"). Special caps and bonnets, usually in black or other dark colours, went with these ensembles. There was mourning jewellery, often made of jet. Jewellery was also occasionally made from the hair of the deceased. The wealthy would wear cameos or lockets designed to hold a lock of the deceased's hair or some similar relic.  Widows were expected to wear special clothes to indicate that they were in mourning for up to four years after the death, although a widow could choose to wear such attire for the rest of her life. To change the costume earlier was considered disrespectful to the deceased and, if the widow was still young and attractive, suggestive of potential sexual promiscuity. Those subject to the rules were slowly allowed to re-introduce conventional clothing at specific times; such stages were known by such terms as "full mourning", "half mourning", and similar descriptions. For half mourning, muted colours such as lilac, grey and lavender could be introduced.  Friends, acquaintances, and employees wore mourning to a greater or lesser degree depending on their relationship to the deceased. Mourning was worn for six months for a sibling. Parents would wear mourning for a child for "as long as they feel so disposed". A widow was supposed to wear mourning for two years and was not supposed to enter society for twelve months. No lady or gentleman in mourning was supposed to attend social events while in deep mourning. In general, servants wore black armbands when there had been a death in the household. However, amongst polite company the wearing of a simple black armband was seen as appropriate only for military men, or others compelled to wear uniform in the course of their duties—a black arm band instead of proper mourning clothes was seen as a degradation of proper etiquette and to be avoided. In general, men were expected to wear mourning suits (not to be confused with morning suits) of black frock coats with matching trousers and waistcoats. In the later interbellum period between World War I and World War II, as the frock coat became increasingly rare, the mourning suit consisted of a black morning coat with black trousers and waistcoat, essentially a black version of the morning suit worn to weddings and other occasions, which would normally include coloured waistcoats and striped or checked trousers.  Formal mourning culminated during the reign of Queen Victoria, whose long and conspicuous grief over the death of her husband, Prince Albert, may have had much to do with it. Although fashions began to be more functional and less restrictive for the succeeding Edwardians, appropriate dress for men and women—including that for the period of mourning—was still strictly prescribed and rigidly adhered to. In 2014, The Metropolitan Museum of Modern Art mounted an exhibition of women's mourning attire from the nineteenth century entitled "".  The customs were not universally supported, with Charles Voysey writing that it "adds needlessly to the gloom and dejection of really afflicted relatives must be apparent to all who have ever taken part in these miserable rites.".  The rules were gradually relaxed, and it became acceptable practise for both sexes to dress in dark colours for up to a year after a death in the family. By the late 20th century, this no longer applied, and black had been widely adopted by women in cities as a fashionable colour.

North America.

United States.

Mourning generally followed English forms into the 20th century. Black dress is still considered proper etiquette for attendance at funerals, but extended periods of wearing black dress are no longer expected. However, attendance at social functions such as weddings when a family is in deep mourning is frowned upon. Men who share their father's given name and use a suffix such as "Junior" retain the suffix at least until the father's funeral is complete.  In the antebellum South, with social mores that imitated those of England, mourning was just as strictly observed by the upper classes.  In the 19th century, mourning could be quite expensive, as it required a whole new set of clothes and accessories or, at the very least, overdying existing garments and taking them out of daily use. For a poorer family, this was a strain on their resources.  At the end of "The Wonderful Wizard of Oz", Dorothy explains to Glinda that she must return home because her aunt and uncle cannot afford to go into mourning for her because it was too expensive.  A late-20th and early-21st century North American mourning phenomenon is the "rear window memorial decal." This is a vinyl window-cling decal memorializing a deceased loved one that is large and is prominently displayed in the rear windows of cars and trucks belonging to close family members and sometimes friends. It often contains birth and death dates, although some contain sentimental phrases or designs as well.

The Pacific.

Tonga.

In Tonga, family members of deceased persons wear black for an extended time, with large plain Taʻovala. Often, black bunting is hung from homes and buildings. In the case of the death of royalty, the entire country adopts mourning dress and black and purple bunting is displayed from most buildings.

State and official mourning.

State mourning or, in the case of a monarchy, court mourning refers to displays of mourning behavior on the death of a public figure or member of a royal family.  The degree and duration of public mourning is generally decreed by a protocol officer. It was not unusual for the British court to declare that all citizens should wear full mourning for a specified period after the death of the monarch or that the members of the court should wear full- or half-mourning for an extended time. On the death of Queen Victoria (January 22, 1901), the "Canada Gazette" published an "extra" edition announcing that court mourning would continue until January 24, 1902. It directed the public to wear deep mourning until March 6, 1901 and half-mourning until April 17, 1901.  The black-and-white costumes designed by Cecil Beaton for the Royal Ascot sequence in "My Fair Lady" were inspired by the "Black Ascot" of 1910, when the court was in mourning for Victoria's son, Edward VII.  All over the world, states usually declare a period of 'official mourning' after the death of a Head of State. The signs may vary but usually include the lowering or posting half-mast of flags on public buildings. (In contrast, the Royal Standard of the United Kingdom is not flown at half-mast, because there is always a monarch on the throne.)  In January 2006, on the death of Jaber Al-Ahmad Al-Jaber Al-Sabah, the Emir of Kuwait, a mourning period of 40 days was declared. In Tonga, the official mourning lasts for a year; only afterwards is the royal heir crowned the new king.  On the other hand, the principle of continuity of the State must be respected. The principle is reflected in the French saying ""Le Roi est mort, vive le Roi!"" [The king is dead, long live the king!]. Regardless of the formalities of mourning, power must be handed on; if the succession is uncontested, that is best done immediately. Yet, a short interruption of work in the civil service may result from one or more days of closing the offices, especially on the day of the State funeral.

Religions and customs.

Confucianism.

There are five grades of mourning obligations in the Confucian Code. A man is expected to honor most of those descended from his great-great-grandfather, and most of their wives. One's father (and mother) would merit 27 months. One's grandfather on the male side, as well as one's wife, would be grade two, or twelve months of austerities. A paternal uncle is grade three at nine months. Grade four is reserved for one's father's first cousin, maternal grandparents, siblings and sister's children (five months). First cousins once removed, second cousins and a man's wife's parents were to get grade five (three months).

Christianity.

Eastern Christianity.

Orthodox Christians usually hold the funeral either the day after death or on the third day, and always during the daytime. In traditional Orthodox communities the body of the departed would be washed and prepared for burial by family or friends, and then placed in the coffin in the home. A house in mourning would be recognizable by the lid of the coffin, with a cross on it, and often adorned with flowers, set on the porch by the front door.  Special prayers are held on the third, seventh or ninth (number varies in different national churches), and 40th days after death; the third, sixth and ninth or twelfth month; and annually thereafter in a memorial service, for up to three generations. Kolyva is ceremoniously used to honor the dead.  Sometimes men in mourning will not shave for the 40 days. In Greece and other Orthodox countries, it is not uncommon for widows to remain in mourning dress for the rest of their lives.  When an Orthodox bishop dies, a successor is not elected until after the 40 days of mourning are completed, during which period his diocese is said to be "widowed".  The 40th day has great significance in Orthodox religion. That is the period during which soul of deceased wanders on earth. On the 40th day ascension of his soul occurs. Therefore, it's the most important day in mourning period, when special prayers should be held on grave site of deceased.  As in the Roman Catholic rites, there can be symbolic mourning. During Holy Week, some temples in the Church of Cyprus draw black curtains across the icons. The services of Good Friday and Holy Saturday morning are patterned in part on the Orthodox Christian burial service, and funeral lamentations.

Western Christianity.

The European social forms are, in general, forms of Christian religious expression transferred to the greater community.  In the Roman Catholic Church, the Mass of Paul VI, adopted in 1969, allows several options for the liturgical color used in Masses for the Dead. Before the liturgical reform, black was the ordinary color for funeral Masses; in the revised use, several options are available, though black is the norm. According to the General Instruction of the Roman Missal (§346d-e), black vestments is to be worn at Offices and Masses for the dead; an indult was given for several countries to use violet or white vestments, and in some of those nations those colours have largely supplanted the use of black vestments.  Christian churches often go into mourning symbolically during the period of Lent to commemorate the sacrifice and death of Jesus. Customs vary among the denominations and include the covering or removal of statuary, icons and paintings, and use of special liturgical colors, such as violet/purple, during Lent and Holy Week.  In more formal congregations, parishioners also dress according to specific forms during Holy Week, particularly on Maundy Thursday and Good Friday, when it is common to wear black or sombre dress or, as mentioned, the liturgical color purple.

Hinduism.

Death is not seen as the final "end", but is seen as a turning point in the seemingly endless journey of the indestructible "atman" or soul through innumerable bodies of animals and people. Hence, Hinduism prohibits excessive mourning or lamentation upon death, as this can hinder the passage of the departed soul towards its journey ahead: "As mourners will not help the dead in this world, therefore (the relatives) should not weep, but perform the obsequies to the best of their power."  Hindu mourning is described in dharma shastras. It begins immediately after the cremation of the body and ends on the morning of the thirteenth day. Traditionally the body is cremated within 24 hours after death; however, cremations are not held after sunset or before sunrise. Immediately after the death, an oil lamp is lit near the deceased, and this lamp is kept burning for three days.  Hinduism associates death with ritual impurity for the immediate blood family of the deceased, hence during these mourning days, the immediate family must not perform any religious ceremonies (except funerals), must not visit temples or other sacred places, must not serve the sages (holy men), must not give alms, must not read or recite from the sacred scriptures, nor can they attend social functions such as marriages, parties, etc. The family of the deceased is not expected to serve any visiting guests food or drink. It is customary that the visiting guests do not eat or drink in the house where the death has occurred. The family in mourning are required to bathe twice a day, eat a single simple vegetarian meal, and try to cope with their loss.  On the day on which the death has occurred, the family do not cook; hence usually close family and friends will provide food for the mourning family. White clothing (the color of purity) is the color of mourning, and many will wear white during the mourning period.  The male members of the family do not cut their hair or shave, and the female members of the family do not wash their hair until the 10th day after the death. If the deceased was young and unmarried, the "Narayan Bali" is performed by the Pandits. The Mantras of "Bhairon Paath" are recited. This ritual is performed through the person who has given the Mukhagni (Ritual of giving fire to the dead body).  On the morning of the 13th day, a Śrāddha ceremony is performed. The main ceremony involves a fire sacrifice, in which offerings are given to the ancestors and to gods, to ensure the deceased has a peaceful afterlife. Pind Sammelan is performed to ensure the involvement of the departed soul with that of God. Typically after the ceremony, the family cleans and washes all the idols in the family shrine; and flowers, fruits, water and purified food are offered to the gods. Then, the family is ready to break the period of mourning and return to daily life.

Islam.

In Shi’ah Islam, examples of mourning practices are held annually in the month of Muharram, i.e. the first month of Islamic Lunar calendar. This mourning is held in the commemoration of Imam Al Husayn ibn Ali, who was martyred along with his 72 companions by Yazid bin Muawiyah. Shi’ah Muslims wear black clothes and take out processions on road to mourn on the tragedy of Karbala.  Shi’ah Muslims also mourn the death of Fatima (the only daughter of Muhammad) and the Shi’ah Imams.  Mourning is observed in Islam by increased devotion, receiving visitors and condolences, and avoiding decorative clothing and jewelry.  Loved ones and relatives are to observe a three-day mourning period. Widows observe an extended mourning period (Iddah), four months and ten days long, in accordance with the Qur'an 2:234. During this time, she is not to remarry, move from her home, or wear decorative clothing or jewelry.  Grief at the death of a beloved person is normal, and weeping for the dead is allowed in Islam. What is prohibited is to express grief by wailing ("bewailing" refers to mourning in a loud voice), shrieking, tearing hair or clothes, breaking things, scratching faces, or uttering phrases that make a Muslim lose faith.

Directives for widows.

The Qur'an prohibits widows from engaging themselves for four lunar months and ten days after the death of their husbands. According to Qur'an: Islamic scholars consider this directive a balance between mourning a husband's death and protection of the widow from censure that she became interested in remarrying too soon after her husband’s death. This is also to ascertain whether or not she is pregnant.

Judaism.

Judaism looks upon mourning as a process by which the stricken can re-enter into society, and so provides a series of customs that make this process gradual. The first stage, observed as all the stages are by immediate relatives (parents, spouse, siblings and children) is the Shiva (literally meaning seven), which consists of the first seven days after the funeral. The second stage is the Shloshim (thirty), referring to the thirty days following the death. The period of mourning after the death of a parent lasts one year. Each stage places lighter demands and restrictions than the previous one in order to reintegrate the bereaved into normal life.  The most known and central stage is Shiva, which is a Jewish mourning practice in which people adjust their behaviour as an expression of their bereavement for the week immediately after the burial. In the West, typically, mirrors are covered and a small tear is made in an item of clothing to indicate a lack of interest in personal vanity. The bereaved dress simply and sit on the floor, short stools or boxes rather than chairs when receiving the condolences of visitors. In some cases relatives or friends take care of the bereaved's house chores, as cooking and cleaning. English speakers use the expression "to sit shiva".  During the Shloshim the mourners are no longer expected to sit on the floor or be taken care of (cooking/cleaning). However, some customs still apply. There is a prohibition on getting married or attending any sort of celebrations and men refrain from shaving or cutting their hair.  Restrictions during the year of mourning include not wearing new clothes, not listening to music and not attending celebrations. In addition, the sons of the deceased recite the Kaddish prayer for the first eleven months of the year.

Mourning is, in the simplest sense, grief over someone's death. The word is also used to describe a cultural complex of behaviours in which the bereaved participate or are expected to participate. Customs vary between cultures and evolve over time, though many core behaviors remain constant.

Trauer ist eine durch einen schwerwiegenden Verlust verursachte Gemütsstimmung, die etwa durch den Verlust einer geliebten oder verehrten Person, durch einen ideellen Verlust oder die Erinnerung an solche Verluste hervorgerufen wird.


Origin and development.

Unicode has the explicit aim of transcending the limitations of traditional character encodings, such as those defined by the ISO/IEC 8859 standard, which find wide usage in various countries of the world but remain largely incompatible with each other. Many traditional character encodings share a common problem in that they allow bilingual computer processing (usually using Latin characters and the local script), but not multilingual computer processing (computer processing of arbitrary scripts mixed with each other).  Unicode, in intent, encodes the underlying characters—graphemes and grapheme-like units—rather than the variant glyphs (renderings) for such characters. In the case of Chinese characters, this sometimes leads to controversies over distinguishing the underlying character from its variant glyphs (see Han unification).  In text processing, Unicode takes the role of providing a unique "code point"—a number, not a glyph—for each character. In other words, Unicode represents a character in an abstract way and leaves the visual rendering (size, shape, font, or style) to other software, such as a web browser or word processor. This simple aim becomes complicated, however, because of concessions made by Unicode's designers in the hope of encouraging a more rapid adoption of Unicode.  The first 256 code points were made identical to the content of ISO/IEC 8859-1 so as to make it trivial to convert existing western text. Many essentially identical characters were encoded multiple times at different code points to preserve distinctions used by legacy encodings and therefore, allow conversion from those encodings to Unicode (and back) without losing any information. For example, the "fullwidth forms" section of code points encompasses a full duplicate of the Latin alphabet because Chinese, Japanese, and Korean (CJK) fonts contain two versions of these letters, "fullwidth" matching the width of the CJK characters, and normal width. For other examples, see duplicate characters in Unicode.

History.

Based on experiences with the Xerox Character Code Standard (XCCS) since 1980, the origins of Unicode date to 1987, when Joe Becker from Xerox with Lee Collins and Mark Davis from Apple, started investigating the practicalities of creating a universal character set. With additional input from Peter Fenwick and Dave Opstad, Joe Becker published a draft proposal for an "international/multilingual text character encoding system in August 1988, tentatively called Unicode". He explained that "[t]he name 'Unicode' is intended to suggest a unique, unified, universal encoding".  In this document, entitled "Unicode 88", Becker outlined a 16-bit character model: Unicode is intended to address the need for a workable, reliable world text encoding. Unicode could be roughly described as "wide-body ASCII" that has been stretched to 16 bits to encompass the characters of all the world's living languages. In a properly engineered design, 16 bits per character are more than sufficient for this purpose. His original 16-bit design was based on the assumption that only those scripts and characters in modern use would need to be encoded: Unicode gives higher priority to ensuring utility for the future than to preserving past antiquities. Unicode aims in the first instance at the

Unicode Consortium.

The Unicode Consortium is a nonprofit organization that coordinates Unicode's development. Full members include most of the main computer software and hardware companies with any interest in text-processing standards, including Adobe, Apple, Google, IBM, Microsoft, and Oracle Corporation.  Over the years several countries or

Scripts covered.

Unicode covers almost all scripts (writing systems) in current use today.  A total of 154 scripts are included in the latest version of Unicode (covering alphabets, abugidas and syllabaries), although there are still scripts that are not yet encoded, particularly those mainly used in historical, liturgical, and academic contexts. Further additions of characters to the already encoded scripts, as well as symbols, in particular for mathematics and music (in the form of notes and rhythmic symbols), also occur.  The Unicode Roadmap Committee (Michael Everson, Rick McGowan, Ken Whistler, V.S. Umamaheswaran) maintain the list of scripts that are candidates or potential candidates for encoding and their tentative code block assignments on the Unicode Roadmap page of the Unicode Consortium Web site.

Versions.

Unicode is developed in conjunction with the International Organization for Standardization and shares the character repertoire with ISO/IEC 10646: the Universal Character Set. Unicode and ISO/IEC 10646 function equivalently as character encodings, but "The Unicode Standard" contains much more information for implementers, covering—in depth—topics such as bitwise encoding, collation and rendering. The Unicode Standard enumerates a multitude of character properties, including those needed for supporting bidirectional text. The two standards do use slightly different terminology.  The Unicode Consortium first published "The Unicode Standard" in 1991 (version 1.0), and has published new versions on a regular basis since then. The latest version of the Unicode Standard,

Architecture and terminology.

The Unicode Standard defines a "codespace" of numerical values ranging from 0 through 10FFFF, called "code points" and denoted as U+0000 through U+10FFFF ("U+" plus the code point value in hexadecimal, prepended with leading zeros as necessary to result in a minimum of four digits, "e. g.", U+00F7 for the division sign, ÷, versus U+13254 for the Egyptian hieroglyph designating a reed shelter or a ), respectively. Out of these 2 + 2 defined code points, the code points from U+D800 through U+DFFF, which are used to encode surrogate pairs in UTF-16, are reserved by the Standard and may not be used to encode valid characters, resulting in a net total of 2 − 2 + 2 = 1,112,064 possible code points corresponding to valid Unicode characters. Not all of these code points necessarily correspond to visible characters; several, for example, are assigned to control codes such as carriage return.

Code point planes and blocks.

The Unicode codespace is divided into seventeen "planes", numbered 0 to 16:  All code points in the BMP are accessed as a single code unit in UTF-16 encoding and can be encoded in one, two or three bytes in UTF-8. Code points in Planes 1

General Category property.

Each code point has a single General Category property. The major categories are denoted: Letter, Mark, Number, Punctuation, Symbol, Separator and Other. Within these categories, there are subdivisions. In most cases other properties must be used to sufficiently specify the characteristics of a code point. The possible General Categories are:  Code points in the range U+D800–U+DBFF (1,024 code points) are known as high-surrogate code points, and code points in the range U+DC00–U+DFFF (1,024 code points) are known as low-surrogate code points. A high-surrogate code point followed by a low-surrogate code point form a surrogate pair in UTF-16 to represent code points greater than U+FFFF. These code points otherwise cannot be used (this rule is ignored often in practice especially when not using UTF-16).  A small set of code points are guaranteed never to be used for encoding characters, although applications may make use of these code points internally if they wish. There are sixty-six of these noncharacters: U+FDD0–U+FDEF and any code point ending in the value FFFE or FFFF (i.e., U+FFFE, U+FFFF, U+1FFFE, U+1FFFF,... U+10FFFE, U+10FFFF). The set of noncharacters is stable, and no new noncharacters will ever be

Abstract characters.

The set of graphic and format characters defined by Unicode does not correspond directly to the repertoire of "abstract characters" that is representable under Unicode. Unicode encodes characters by associating an abstract character with a particular code point. However, not all abstract characters are encoded as a single Unicode character, and some abstract characters may be represented in Unicode by a sequence of two or more characters. For example, a Latin small letter "i" with an ogonek, a dot above, and

Ready-made versus composite characters.

Unicode includes a mechanism for modifying characters that greatly extends the supported glyph repertoire. This covers the use of combining diacritical marks that may be added after the base character by the user. Multiple combining diacritics may be simultaneously applied to the same character. Unicode also contains precomposed versions of most letter/diacritic combinations in normal use. These make conversion to and from legacy encodings simpler, and allow applications to use Unicode as an internal text format without having to implement combining characters. For example, "é" can be represented in Unicode as U+0065 () followed by U+0301 (), but it can also be represented as the precomposed character U+00E9 (). Thus, in many cases, users have multiple ways of encoding the same character. To deal with this, Unicode provides the mechanism of canonical equivalence.  An

Ligatures.

Many scripts, including Arabic and Devanāgarī, have special orthographic rules that require certain combinations of letterforms to be combined into special ligature forms. The rules governing ligature formation can be quite complex, requiring special script-shaping technologies such as ACE (Arabic Calligraphic Engine by DecoType in the 1980s and used to generate all the Arabic examples in the printed editions of the Unicode Standard), which became the proof of concept for OpenType (by Adobe and Microsoft), Graphite (by SIL International), or AAT (by Apple).  Instructions are also embedded in fonts to tell the operating system how

Standardized subsets.

Several subsets of Unicode are standardized: Microsoft Windows since Windows NT 4.0 supports WGL-4 with 656 characters, which is considered to support all contemporary European languages using the Latin, Greek, or Cyrillic script. Other standardized subsets of Unicode include the Multilingual European Subsets:  MES-1 (Latin scripts only, 335 characters), MES-2 (Latin, Greek and Cyrillic 1062 characters) and MES-3A & MES-3B (two

Mapping and encodings.

Several mechanisms have been specified for storing a series of code points as a series of bytes. Unicode defines two mapping methods: the "Unicode Transformation Format" (UTF) encodings, and the "Universal Coded Character Set" (UCS) encodings. An encoding maps (possibly a subset of) the range of Unicode "code points" to sequences of values in some fixed-size range, termed "code units". All UTF encodings map code points to a unique sequence of bytes. The numbers in the names of the encodings indicate the number of bits per code unit (for UTF encodings) or the number of bytes per code unit (for UCS encodings and UTF-1).

Adoption.

Operating systems.

Unicode has become the dominant scheme for internal processing and storage of text. Although a great deal of text is still stored in legacy encodings, Unicode is used almost exclusively for building new information processing systems. Early adopters tended to use UCS-2 (the fixed-width two-byte precursor to UTF-16) and later moved to UTF-16 (the variable-width current standard), as this was the least disruptive way to add support for non-BMP characters. The best known such system is Windows NT (and its descendants, Windows 2000, Windows XP, Windows Vista,

Input methods.

Because keyboard layouts cannot have simple key combinations for all characters, several operating systems provide alternative input methods that allow access to the entire repertoire.  ISO/IEC 14755, which standardises methods for entering Unicode characters from their code points, specifies several methods. There is the "Basic method", where a "beginning sequence" is followed by the hexadecimal representation of the code point and the "ending sequence".

Email.

MIME defines two different mechanisms for encoding non-ASCII characters in email, depending on whether the characters are in email headers (such as the "Subject:"), or in the text body of the message; in both cases, the original character set is identified as well as a transfer encoding. For email transmission of Unicode, the UTF-8 character set and the Base64 or the Quoted-printable

Web.

All W3C recommendations have used Unicode as their "document character set" since HTML 4.0. Web browsers have supported Unicode, especially UTF-8, for many years. There used to be display problems resulting primarily from font related issues; e.g. v 6 and older of Microsoft Internet Explorer did not render many code points unless explicitly told to use a font that contains them.  Although syntax rules may affect the order in which characters are allowed to

Fonts.

Unicode is not in principle concerned with fonts "per se", seeing them as implementation choices. Any given character may have many allographs, from the more common bold, italic and base letterforms to complex decorative styles. A font is "Unicode compliant" if the glyphs in the font can be accessed using code points defined in the Unicode standard. The standard does not specify a minimum number of characters that must be included in the font; some fonts have quite a small repertoire.  Free and retail fonts based on Unicode are widely available, since TrueType and OpenType support

Newlines.

Unicode partially addresses the newline problem that occurs when trying to read a text file on different platforms. Unicode defines a large number of characters that conforming applications should recognize as line terminators.  In terms of the newline, Unicode introduced and. This was an attempt to provide a Unicode solution to encoding paragraphs and lines semantically, potentially replacing all of the various platform solutions. In doing so, Unicode does provide a

Issues.

Philosophical and completeness criticisms.

Han unification (the identification of forms in the East Asian languages which one can treat as stylistic variations of the same historical character) has become one of the most controversial aspects of Unicode, despite the presence of a majority of experts from all three regions in the Ideographic Research Group (IRG), which advises the Consortium and ISO on additions to the repertoire and on Han unification.  Unicode has been criticized for failing to separately encode older and alternative forms of kanji which, critics argue, complicates the processing of ancient Japanese and uncommon Japanese names. This is often due to the fact that Unicode encodes characters rather than glyphs (the visual representations of the basic character that often vary from one language to another). Unification of glyphs leads to the perception that the languages themselves, not just the basic character representation, are being merged. There have been several attempts to create alternative encodings that preserve the

Mapping to legacy character sets.

Unicode was designed to provide code-point-by-code-point round-trip format conversion to and from any preexisting character encodings, so that text files in older character sets can be converted to Unicode and then back and get back the same file, without employing context-dependent interpretation. That has meant that inconsistent legacy architectures, such as combining diacritics and precomposed characters, both exist in Unicode, giving more than one method of representing some text. This is most pronounced in the three different encoding forms for Korean Hangul. Since version 3.0, any precomposed characters that can be represented by a combining sequence of already existing characters can no longer be

Indic scripts.

Indic scripts such as Tamil and Devanagari are each allocated only 128 code points, matching the ISCII standard. The correct rendering of Unicode Indic text requires transforming the stored logical order characters into visual order and the forming of ligatures (aka conjuncts) out of components. Some local scholars argued in favor of assignments of Unicode code points to these ligatures, going against the practice for other writing systems, though Unicode contains some Arabic and other ligatures for backward compatibility purposes only. Encoding of any new ligatures in Unicode will not happen, in part because the set of ligatures is font-dependent, and Unicode is an encoding independent of font variations. The same kind of issue arose for the Tibetan script in 2003 when the Standardization

Combining characters.

Characters with diacritical marks can generally be represented either as a single precomposed character or as a decomposed sequence of a base letter plus one or more non-spacing marks. For example, ḗ (precomposed e with macron and acute above) and ē (e followed by the combining macron above and combining acute above) should be rendered identically, both appearing as an e with

Anomalies.

The Unicode standard has imposed rules intended to guarantee stability. Depending on the strictness of a rule, a change can be prohibited or allowed. For example, a "name" given to a code point cannot and will not change. But a "script" property is more flexible, by Unicode's own rules. In version 2.0, Unicode changed many code point "names" from version

Unicode is an information technology (IT) standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard is maintained by the Unicode Consortium, and, there is a repertoire of (these characters consist of 143,696 graphic characters and 163 format characters) covering 154 modern and historic scripts, as well as multiple symbol sets and emoji. The character repertoire of the Unicode Standard is synchronized with ISO/IEC 10646, and both are code-for-code identical.

Unicode (Aussprachen: am. Englisch [], brit. Englisch []; dt. []) ist ein internationaler Standard, in dem langfristig für jedes sinnvolle Schriftzeichen oder Textelement aller bekannten Schriftkulturen und Zeichensysteme ein digitaler Code festgelegt wird. Ziel ist es, die Verwendung unterschiedlicher und inkompatibler Kodierungen in verschiedenen Ländern oder Kulturkreisen zu beseitigen. Unicode wird ständig um Zeichen weiterer Schriftsysteme ergänzt.