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Lightsaber

A lightsaber is a fictional energy sword featured throughout Star Wars. A typical lightsaber is depicted as a luminescent laser sword about 3 ft in length emitted from a metal hilt around 10.5 in in length. First introduced in the original Star Wars film, it has since appeared in most Star Wars films, with at least one lightsaber duel occurring in each installment of the "Skywalker saga". The lightsaber's distinct appearance was created using rotoscoping for the original films, and with digital effects for the prequel and sequel trilogies.

In the Star Wars universe, the lightsaber is the signature weapon of the light-side-wielding Jedi Order and the dark-side-wielding Sith Order. However, the lightsaber can also be wielded by non-Force-sensitive characters as an ordinary weapon or tool. The Jedi use different colored lightsabers. The most common lightsaber colors are blue and green, but other colors also exist, that being purple, white, black and yellow. The Sith wield exclusively red-bladed sabers to distinguish themselves from the Jedi. The color of a lightsaber's blade is given by a kyber crystal. A kyber crystal has no color until it is approached by a Jedi, it then turns into a color determined by the wielders connection to the Force. A lightsaber's hilt is built by its wielder and is, therefore, unique in design. There are several variations outside of the traditional single-bladed lightsaber, such as the double-bladed lightsaber (most famously wielded by Darth Maul), the curved-hilted lightsaber (wielded by Asajj Ventress and most famously by Count Dooku), crossguard lightsabers (used by Kylo Ren and occasionally by Jedi), and the Darksaber, forged by the Mandalorian Jedi Tarre Vizsla, but primarily wielded by the non-Force-sensitive Mandalorian rulers of Mandalore (including Pre Vizsla, Maul, Bo-Katan Kryze, Moff Gideon, and Din Djarin).

As presented in the films, a lightsaber's energy blade can cut, burn, and melt through most substances with little resistance. It leaves cauterized wounds in flesh, but can be deflected by another lightsaber blade, by energy shields, or by the metal beskar (found in Mandalorian armor) and phrik (metal used to create electrostaffs). The blade has even been used as a tool to weld metal. Other times, the lightsaber has been shown to cause bleeding wounds in the flesh, sometimes accompanied by burns. Some exotic saber-proof melee weapons have been introduced in the Expanded Universe as well as later episodic films. Lightsabers can also reflect blaster bolts, allowing a wielder with Jedi reflexes to turn an enemy's own gunfire against them. An active lightsaber gives off a distinctive hum, which rises in pitch and volume as the blade is moved rapidly through the air. Bringing the blade into contact with another lightsaber's blade produces a loud crackle.

The lightsaber has become one of the most widely recognized elements of the Star Wars franchise. In 2008, a survey of approximately 2,000 film fans found it to be the most popular weapon in film history.

Prop construction
For the original Star Wars film, the film prop hilts were constructed by John Stears from old Graflex press camera flash battery packs and other pieces of hardware. The full-sized sword props were designed to appear ignited onscreen, by later creating an "in-camera" glowing effect in post-production. The blade is a three-sided rod which was coated with a Scotchlite retroreflector array, the same sort used for highway signs. A lamp was positioned to the side of the taking camera and reflected towards the subject through 45-degree angled glass so that the sword would appear to glow from the camera's point of view.

Set decorator Roger Christian found the handles for the Graflex Flash Gun in a photography shop in Great Marlborough Street, in London's West End. He then added cabinet T-track to the handles, securely attaching them with cyanoacrylate glue. Adding a few "greebles" (surface details), Christian managed to hand-make the first prototype of a lightsaber prop for Luke before production began. George Lucas decided he wanted to add a clip to the handle, so that Luke could hang it on his belt. Once Lucas felt the handle was up to his standards, it went to John Stears to create the wooden dowel rod with front-projection paint so that the animators would have a glow of light to enhance later on in post production. Due to lack of preparation time, Christian's prototype and a second spare were used for the shooting in Tunisia, where filming on Star Wars began. It was discovered, however, that the glowing effect was greatly dependent on the rod's orientation to the camera, and during the Obi-Wan Kenobi/Darth Vader duel, they could clearly be seen as rods. Because of this, the glow would be added in post-production through rotoscoping, which also allowed for diffusion to be employed to enhance the glow.

While original trilogy hilts were typically constructed using found parts, during the prequel and sequel trilogies a different process was sometimes used. Hilts were first machined out of metal materials. Then casts would be made using the metal hilts to create resin copies that were used on screen. The resin was often molded over a metal rod that a dueling blade could be attached to for fight sequences.

Visual effects
Korean animator Nelson Shin, who was working for DePatie–Freleng Enterprises at the time, was asked by his manager if he could animate the lightsaber in the live-action scenes of a film. After Shin accepted the assignment, the live-action footage was given to him. He drew the lightsabers with a rotoscope, an animation which was superimposed onto the footage of the physical lightsaber blade prop. Shin explained to the people from Lucasfilm that since a lightsaber is made of light, the sword should look "a little shaky" like a fluorescent tube. He suggested inserting one frame that was much lighter than the others while printing the film on an optical printer, making the light seem to vibrate. Shin also recommended adding a degausser sound on top of the other sounds for the weapon since the sound would be reminiscent of a magnetic field. The whole process took one week, surprising his company. Lucasfilm showed Shin the finished product, having followed his suggestions to use an X-Acto knife to give the lightsaber a very sharp look, and to have sound accompany the weapon's movements.

Sound
The lightsaber sound effect was developed by sound designer Ben Burtt as a combination of the hum of idling interlock motors in aged movie projectors and interference caused by a television set on a shieldless microphone. Burtt discovered the latter accidentally as he was looking for a buzzing, sparking sound to add to the projector-motor hum.

The pitch changes of lightsaber movement were produced by playing the basic lightsaber tone on a loudspeaker and recording it on a moving microphone, generating Doppler shift to mimic a moving sound source.

Depiction
Lightsabers were present in the earliest drafts as mundane plasma weapons that were used alongside laser guns. The introduction of the Force in a later revision made the Jedi and the Sith supernaturally skilled; initially, they were only portrayed as swordsmen. The lightsaber became the Force-user's tool, described in A New Hope by Obi-Wan Kenobi as "not as clumsy or random as a blaster. An elegant weapon, for a more civilized age". The source of a lightsaber's power is a kyber crystal. These crystals are also the power source of the Death Star's superlaser.

In films such as Revenge of the Sith and The Last Jedi, melee weapons such as the electrostaff and plasma-lined blades deflect lightsabers.

Types
Lightsabers are depicted as hand-built as part of a Jedi's or Sith's training regimen. Each lightsaber is unique, though some may bear resemblance to others, especially if there is a connection between the builders. The hilt of most lightsabers are straight and predominantly cylindrical, though there are other lightsaber hilt types. The first film appearance of a dual-bladed lightsaber (first depicted in the comic series Tales of the Jedi) was in The Phantom Menace, wielded by Darth Maul; it consists of two regular lightsabers joined at their butt ends each producing a blade independently. Count Dooku, beginning with the character's first appearance in Attack of the Clones, is shown to have a lightsaber with a curved hilt. The video game Star Wars: The Force Unleashed introduced two other variants: a lightsaber pike (a lightsaber with a shorter blade but a long handle, resembling a spear) and a Tonfa-style lightsaber with right-angle hilt.

The Star Wars expanded universe adds several lightsaber types, including short and dual-phase (adjustable length) weapons. In Star Wars Rebels, Ezra Bridger's original lightsaber is a hybrid that features a fully functional blaster pistol built into the handle. Kylo Ren, introduced in The Force Awakens, uses a lightsaber that features two crosshilt blades, giving it the appearance of a greatsword. His blade also has an unstable, fiery appearance, explained in canon reference books as stemming from a cracked kyber crystal. The Inquisitors of the Galactic Empire are depicted as wielding a unique variation of a double-bladed saber, mounted on a rotating ring enabling the blades 360 degrees of rotation and short-term flight capability. More obscure lightsaber variations, such as the "lightwhip", an elongated flexible blade used in a matter akin to a whip, the "lightclub", an enlarged standard lightsaber, and the "shoto", a dramatically smaller variation often paired with a standard sized saber have also made appearances.

Colors
Lightsabers in the first two released films, A New Hope and The Empire Strikes Back, had blades that were either blue (for the Jedi) or red (for the Sith). Luke Skywalker's new lightsaber in Return of the Jedi was colored blue during the initial editing of the film, and appears so in both an early movie trailer and the official theatrical posters; it was later changed to green in the film's final edit after initial viewings and screen tests by the filmmakers, who felt that it would better stand out against the blue sky of Tatooine in outdoor scenes, and this color change is also reflected in the film's re-release posters. Mace Windu's purple-bladed lightsaber, as first seen in Attack of the Clones, was requested by the actor Samuel L. Jackson, who believed the color, which is his personal favorite, would make his character be easily recognized among other Jedi. Jackson is known to frequently request that the characters he plays use an item that is purple in color. The Clone Wars showed the guardians of the Jedi Temple wielding yellow-bladed lightsabers, and, at the end of The Rise of Skywalker, Rey is shown to have built a yellow-bladed lightsaber using part of her staff as the hilt.

As depicted in The Clone Wars and Rebels, the builder of a lightsaber finds a kyber crystal and meditates with it until the crystal acquires a color. The color of this crystal becomes the blade's color when installed into a lightsaber hilt. In the book Star Wars: Ahsoka and the comic series Darth Vader: Dark Lord of the Sith, it is shown that dark side users remove the crystal from a defeated Jedi's lightsaber and concentrate Force energy on it to break its connection to the light side, a process known as "bleeding" to create a red crystal. The process can also be reversed, as shown in Ahsoka, when the titular character does so to a pair of crystals taken from an Inquisitor. She uses them in the pair of white-bladed lightsabers she builds at the end of the novel.

Other colors have appeared in various expanded media projects, including many video games where the player can select their character's lightsaber color.

Darksaber
The Darksaber is a unique lightsaber that has a distinct black blade with a white halo, introduced in Star Wars: The Clone Wars (2008) and subsequently appearing in Star Wars Rebels, where it is described as an ancient lightsaber created by Tarre Vizla, the first Mandalorian to become a Jedi, and later serves as a symbol of Mandalorian authority in the hands of Bo-Katan Kryze. It subsequently appears briefly in the hands of Moff Gideon in the season one finale of The Mandalorian, to whom Kryze had previously surrendered the weapon. By the end of the second season's finale, it belongs to series protagonist Din Djarin, who has bested Gideon for it. In the second episode of the third season of the show, the weapon (nominally) returns to Kryze's ownership, after she defeats a cyborg creature that captures Djarin (it remains in Din Djarin's possession, however), and she officially reclaims the blade in the season's sixth episode. It is destroyed by Gideon in the third season finale.

Choreography
The technical lightsaber choreography for the original Star Wars trilogy was developed by Hollywood sword-master Bob Anderson. Anderson personally trained Mark Hamill (Luke Skywalker) and, in The Empire Strikes Back and Return of the Jedi, performed all the stunts as Darth Vader during the lightsaber duels wearing Vader's costume. Anderson's role in the trilogy was highlighted in the film Reclaiming the Blade where he shared his experiences as a fencer developing the lightsaber techniques for the three original movies.

The lightsaber duels in the Star Wars prequel trilogy were specifically choreographed by stunt-coordinator Nick Gillard to be miniature "stories". For these films, Gillard was the primary sword instructor for Liam Neeson (Qui-Gon Jinn), Ewan McGregor (Obi-Wan Kenobi), Ray Park (Darth Maul) and Hayden Christensen (Anakin Skywalker / Darth Vader) among other actors. His goal in choreographing the action for The Phantom Menace was to create stunts that flow from the story; "You can't just think, 'I'm a stunt coordinator, I'm going to make a big stunt happen'," Gillard said. "It's all about making it tie in nicely with the film so that you don't notice the stunts."

In writing the prequel trilogy, George Lucas said he wanted the lightsaber combat to be "reminiscent of what had been done in the previous films but also something that was more energized. We'd seen old men, young boys, and characters who were half-droid, but we'd never seen a Jedi in his prime. I wanted to do that with a fight that was faster and more dynamic—and we were able to pull that off."

According to Gillard, various lightsaber combat styles were devised for the prequels and intended to further characterize their practitioners.

"I developed different styles for the characters, and gave each of them a flaw or a bonus. So with Obi-Wan Kenobi, for instance, he's got a very business-like style—when he was younger he could border on the flashy and might twirl his lightsaber a bit, because he was taught by Qui-Gon. Qui-Gon was brash, that rubbed off on Obi-Wan and Obi-Wan then taught Anakin, who was way too old to learn anyway... I think the style really worked well. The Jedi style of fighting is an amalgamation of all the great swordfighting styles. Melding them together is the difficult part—to move from a Kendo style to, say, rapier requires a complete change in body and feet movement, and this must look effortless. The style moves seamlessly between the different disciplines, but remains technically correct throughout."

For The Phantom Menace, Gillard set out certain styles and faults for the saber-wielding characters. He added that the Jedi's use of such "a short-range weapon" meant "they would have to be very good at it"; combining a variety of disciplines from various sword fighting styles to martial arts "with a touch of tennis and tree chopping", he created the style seen in the Episode I lightsaber battles.

For The Force Awakens, director J. J. Abrams decided to approach the choreography similarly to how it was done in the original trilogy. Abrams stated that the prequel trilogy choreography was "increasingly spectacular and stylized, almost like dance choreography", but that was not what they really wanted to go for in the new films. He told Empire magazine, "When you look at Star Wars and Empire, they are very different lightsaber battles, but for me they felt more powerful because they were not quite as slick. I was hoping to go for something much more primitive, aggressive and rougher, a throwback to the kind of heart-stopping lightsaber fights I remembered being so enthralled by as a kid."

Merchandise
Since the release of the first film, replicas of lightsabers have been a popular piece of Star Wars merchandise, ranging from inexpensive plastic toys to the "Force FX" series from Master Replicas, deluxe replicas which use LED-lighted tubes and sound effects to create a close audio-visual representation of what is seen on screen.

Over the years, advancements in technology have allowed for the creation of increasingly immersive and realistic lightsaber replicas. One notable development in this regard is the introduction of neopixel lightsabers, which have revolutionized the lightsaber replica market by utilizing a strip of individually addressable RGB LEDs encased within a durable polycarbonate blade. This design allows for a higher level of control over the lightsaber's appearance and behavior.

Disney Parks
Disneyland in California sells lightsaber-themed churros outside its Star Tours attraction.

Disneyland and Disney World (Hollywood Studios) also sell legacy lightsabers which are replicas of the lightsabers seen used by the Jedi, Sith, and other warriors in the movies and television shows such as Darth Vader, Obi-Wan Kenobi, Rey Skywalker, Count Dooku, and Kylo Ren.

Disneyland and Hollywood Studios also offer Savi's Workshop, a place where guests can build their own lightsaber and choose their own kyber crystal, thereby changing the blade color of their own unique lightsaber.

Besides Savi's Workshop, there is another custom lightsaber experience. The Star Trader at Disneyland offers guests a chance to build their own lightsabers, without first paying 200 dollars for the experience.

Attractions
The Jedi Training: Trials of the Temple is a live show where children are selected to learn the teachings of the Jedi Knights, the Force, and the basics of Lightsaber combat to become Padawan learners. The show is present at the Rebels stage next to Star Tours – The Adventures Continue attraction at Disney's Hollywood Studios and at the Tomorrowland Terrace at Disneyland. Additionally, Star Wars: Galactic Starcruiser has incorporated lightsaber training for each guest aboard the spacecraft during their stay. The training is led by the Saja cast members and teaches the fourth form of lightsaber combat, Ataru, to the guests. Both lightsabers and shields are used during training since the guests learn to use Ataru to deflect incoming projectiles. There is no lightsaber-to-lightsaber combat in this attraction and guests must be at least seven years old to participate.

Similar weapons
The virtual reality rhythm game Beat Saber involves the player using two lightsabers in order to slash a series of oncoming cubes.

In Kamen Rider Black RX, the main character, Rider RX also known as Kotaro Minami, uses his lightsaber-ish weapon "Revolcane" to fight the Crisis Empire, a terrorist organization.

In Saban's Masked Rider, the main character, known as Dex Stewart, uses his lightsaber-ish weapon "Electro Saber" to fight Masked Rider's foes.

Parodies
In the 1987 film Spaceballs by Mel Brooks, "the Schwartz" is a play on "the Force", from Star Wars. The lightsabers emanating from the Schwartz-rings, rather than a hilt. The cartoon series Futurama features many lightsaber-style weapons, notably expanding batons used by police. The batons glow and "whoosh" with a lightsaber's distinctive hum, but are used to beat people. In Jim Butcher's Dresden Files novel series, medical examiner and Star Wars fan Waldo Butters wields one of the three holy Swords of the Cross, which re-fashions itself into a lightsaber upon accepting him as its owner. In Yuya Sato's Danganronpa: Togami light novel trilogy, main antagonist Orvin Elevator / Kazuya Togami wields a lightsaber built into their prosthetic arm, to which they are berated for copyright infringement by Genocider Syo / Genocide Jack; in the anime Danganronpa 3: The End of Hope's Peak High School, this same lightsaber is instead depicted as a flaming mechanical katana wielded by Kyosuke Munakata.

Games
With the advent of motion-controlled video games, players were given the opportunity to wield an in-game lightsaber with their own hands. In the seventh generation of video game consoles, there were several Star Wars video games available on the Wii (Lego Star Wars: The Complete Saga, Star Wars: The Force Unleashed, Star Wars: The Clone Wars – Lightsaber Duels, Star Wars: The Clone Wars – Republic Heroes and Lego Star Wars III: The Clone Wars) and one on the Xbox 360 (Kinect Star Wars) that utilized motion controls to wield a lightsaber through arm gestures. Unleashed and Duels, both developed by Krome Studios, have more precise control of the lightsaber, allowing players to swing it in any of five different directions (up, down, left, right or forward) with the Wii Remote, while Kinect takes advantage of the eponymous, camera-based motion controller to grant the player a more fluid, one-to-one control method of swinging the lightsaber.

Prior to the seventh generation, there were also a few earlier Star Wars games that used gesture-based control to simulate lightsaber combat, such as the two bonus levels of the arcade game Star Wars Trilogy, where the player controls Luke Skywalker as he wields his lightsaber against Boba Fett and Darth Vader in Return of the Jedi by pushing a joystick in one of eight directions to follow on-screen offensive and defensive cues, and a TV game released around the time Revenge of the Sith came to theaters, titled Star Wars: Saga Edition – Lightsaber Battle Game, in which the player swings a lightsaber-shaped controller to deflect blaster bolts from infantry (such as battle droids and clone troopers) and duel against characters from across the saga.

By the time Disney purchased Lucasfilm, new technological advances made augmented reality possible, leading to the creation of some more notable motion-controlled lightsaber video games that took advantage of that feature. One of them came in the form of a special activity mode in the official Star Wars fan app on iOS and Android in which players use their smartphone's motion sensors to practice and master blaster deflection with a training droid (which appears on the phone's rear camera), similar to the deflection training exercises featured aboard the Millennium Falcon in A New Hope, while progressing through the ranks of the Jedi or Sith order. Another is in Star Wars: Jedi Challenges, which works with a Lenovo Mirage AR headset, a tracking sensor and a dedicated lightsaber controller that launched in December 2017. One of the multiple game modes available in Challenges, which was jointly developed by Disney and Lenovo, enables players to confront Star Wars villains in lightsaber duels, such as Darth Maul and Kylo Ren.

title: Lightsaber


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Talk:Dihedral group

Untitled
I always thought that D_infinity is the symmetry group of a circle, i.e. the semidirect product of R and C2. But maybe not. Is there a name for this symmetry group then?

 * The infinite dihedral group is usually defined as having presentation {{a,b}; {a^2, b^2}}, from which it can be seen to be countable (unfortunately, the only references I have handy are various sci.math and web hits).

 * Consider, as an extension of the usual definition of dihedral, a group with presentation {{c,b}; {b^2, (bc)^2}}; then b c b = c^-1, b c^n b = c^-n, and so (b c^n)(b c^m) = c^(m-n); similarly, (c^n b)(c^m b) = c^(n-m), and thus all elements are of the form c^n, b c^n or c^n b. By substituting ab for c, we then get strings of the form c^n = ababab...ab, b c^n = babab...ab and c^n b = ababab...aba; so the two presentations are equivalent to Z (semidirect product) C_2.

 * A geometric definition is to start with two axes of symmetry which are separated by an angle which is not a rational multiple of pi; the resulting set of symmetry axes forms the (countable) infinite dihedral group again.

 * I think the symmetry group you're thinking of is called O(2) or SO(2); but I'm none to clear on the terminology of non-discrete groups :).

 * It is O(2), SO(2) only includes rotations.
 * JeffBobFrank 23:02, 21 Feb 2004 (UTC)

Also, the semidirect product of R and C2 is the symmetry group of a straight line, not of a circle. AxelBoldt 22:23, 23 Dec 2004 (UTC)

Notation

 * In mathematics, the dihedral group of order 2n is a certain group for which here the notation Dn is used, but elsewhere the notation D2n is also used, e.g. in the list of small groups.

It would be better to use, at least in Wikipedia, a uniform notation. Is Dn for order 2n more common?--Patrick 12:10, 5 August 2005 (UTC)

 * It really depends on context. Geometers usually prefer Dn, while algebraists prefer D2n. I prefer the former, but that's only because I am more geometrical in thinking. Striving to keep the notation the same in every article is going to be difficult. -- Fropuff 17:03, 5 August 2005 (UTC)

 * I also prefer Dn and have the impression that that is more common in general. Also in April the notation in this article was changed into this, and that was not disputed. Therefore, when I encounter the notation D2n I may change it.--Patrick 08:19, 6 August 2005 (UTC)

 * I prefer the D2n notation. I must confess that I read little in geometry, but as far as I can tell algebraists use D2n exclusively. Nevcamion (talk) 02:04, 15 September 2008 (UTC)

For 3d geometry symmetry, there's actually 3 forms: Dn, Dnh, Dnd, for rotation, reflectional, and mixed symmetry. List_of_spherical_symmetry_groups. Tom Ruen (talk) 02:33, 15 September 2008 (UTC)

The D2n notation should be mentioned somewhere in the article (probably in the first paragraph) as it causes ambiguity otherwise. --82.28.107.134 (talk) 14:05, 20 December 2020 (UTC)

D1 and D2
Is the nth dihedral group usually defined for n=1? The two texts I have on hand (Grillet's Algebra and Fraleigh's A First Course in Abstract Algebra) do not mention D1. In fact, Grillet defines the nth dihedral group only for n>=2. Fraleigh does not even mention D2 for that matter.

Considering D2 now, can someone give some more insight into the nature of this group? I originally operated under the assumption that Dn was a subgroup of the symmetric group of n elements, Sn. This is clearly true when n>=3, but apparently not for n=2, since S2 is isomorphic to C2, while we claim here that D2 is isomorphic to C2 x C2.

Specifically I do not see how D2 fits in with the standard notion that the nth dihedral groups are the symmetries of a regular n-gon. What are the symmetries of a 2-gon, i.e., a line with two endpoints? Seems to me one will only encounter the identity, and what is equivalent to a reflection through the middle. -- Shawn M. O'Hare 13:34, 5 November 2005 (UTC)

 * Systematically, n=1 and n=2 make sense, they are among the discrete point groups in two dimensions: cyclic groups with additionally reflection. As abstract group, the article mentions that Dih1 is a rarely used notation (except in the framework of the series) because it is equal to Z2.

 * I agree that n=1 and n=2 are special in that they are larger than the symmetric groups, corresponding to the fact that 2n > n! for these n. Therefore Dih2 does not correspond to the isometry group of a 2-gon, but to the isometry group of the plane leaving the 2-gon fixed. For a "1-gon" this does not work.--Patrick 14:26, 5 November 2005 (UTC)

 * Your clarification is greatly appreciated. -- Shawn M. O'Hare 12:01, 6 November 2005 (UTC)

Automorphisms
The article should be more specific about the automorphism groups of dihedral groups. The examples are helpful and they suggest the general case, but the general result is not explicitly stated. The group Dihn has n*phi(n) automorphisms. The automorphism group is isomorphic to the group of transformations x → a*x + b (mod n) where a is coprime to n. (Reference: http://www.research.att.com/~njas/sequences/A002618) David Radcliffe 10:09, 12 March 2006 (UTC)

Etymology
I was hoping the article would give me some idea why dihedral groups are called dihedral, but to no avail. Might be a good addition. —The preceding unsigned comment was added by 201.143.107.13 (talk) 04:45, 5 December 2006 (UTC).
 * Good point! I had the same question. I just added a paragraph on the etymology. ★NealMcB★ (talk) 03:22, 19 February 2024 (UTC)

D2 images
The images showing the 'F' letter acted upon by D2 are wrong. Next to the images it's said the D2 is isomorphic to the Klein group, which is abelian. But images state that D2 is non-abelian.

Also, it is clear from second image that if 'r' is the rotation through 90 degrees and 'f' is the reflection, then rf ≠ fr and so the group has more than 4 elements -- in contradiction with the first image.

As I'm trying to learn the subject, I don't know what's actually the correct answer. The three different notations for the dihedral group names employed in the article don't help either.. -- Guygurari 19:34, 26 May 2007 (UTC)

 * The second image shows that D4 (of order 8) is non-abelian. I've corrected the caption. --Zundark 21:30, 26 May 2007 (UTC)

Context needed
I've added the context flag. I was perusing the Luhn algorithm, which led me to the Verhoeff algorithm, which led me to.. what is this? a few pages torn out of the introduction to some advanced maths textbook? It certainly isn't part of an encyclopedia, which is what I thought I was browsing. It really needs a decent introduction before diving into formulae and esoterica. Who studies this, and why? Does it have any real world applications, or is it purely theoretical? A link to a broader topic which subsumes this would be fine, but there's gotta be something...

I suspect many of the more specialized articles in specialized topics will have this same flaw, but that doesn't excuse the problem. MrRedwood 08:54, 15 September 2007 (UTC)

 * I added a link. See also the other links in the intro.--Patrick 11:44, 15 September 2007 (UTC)

Possible revision and expansion
Hi everyone!

I've been working on a possible revision and expansion of this article for a while. Parts of it are now in good enough shape that it might make sense to move them into the main article in some form: Please be aware that when I'm writing a draft, I tend to rewrite as much text as possible, on the theory that we can use whichever version comes out better. I am not proposing a wholesale replacement of this page by the draft—I just think that some parts of the draft are good enough to be moved into the main article.
 * User:Jim.belk/Dihedral Group Draft

In addition to the above draft, I have also written drafts of some possible supporting articles: Let me know what you think. Jim 20:09, 22 September 2007 (UTC)
 * User:Jim.belk/Representation Theory of the Dihedral Group Draft
 * User:Jim.belk/Generalized Dihedral Group Draft

 * See my comments on your draft page's talk page. Cheers. Chas zzz brown 01:48, 23 September 2007 (UTC)

With Chas's help (see User_talk:Jim.belk/Dihedral_Group_Draft), the "Definition" seems ready to be moved into the article. In addition to moving this section, I have reworded the introduction, changed the introductory picture to a snowflake, and reworded the short section on notation. Anyone looking on should feel free to revert or alter any of these edits, or offer comments on how they could be improved.

Chas and I are continuing to work on "symmetry", "algebraic properties", and "generalizations" sections at User:Jim.belk/Generalized Dihedral Group Draft. Anyone else looking on is invited to help with this effort or offer comments on either talk page. Jim 01:14, 24 September 2007 (UTC)

 * I especially liked that Jim mentions solvability of the dihedral groups on his draft page. This would make a nice addition to the main article since it is a general property and since dihedral groups are as simple a nontrivial (nonabelian) illustration of solvability as we can ask for. Hardmath (talk) 20:35, 13 February 2010 (UTC)

Equivalent definitions error
Hi, I think there's an error in the first presentation of the "Equivalent definitions" section. The last relation should be: $srs^{-1} = r^{-1}$. — Preceding unsigned comment added by Suitangi (talk • contribs) 01:59, 22 December 2010 (UTC)
 * The given presentation is correct. Since $$s^2 = 1$$, the element $$s$$ is its own inverse. Jim.belk (talk) 02:12, 22 December 2010 (UTC)

Mention that they are examples of Coxeter / Complex reflection groups
Also in those two articles the dihedral groups are written as I_2(m) 129.215.104.159 (talk) 16:38, 27 July 2011 (UTC)

History and applications
This are two different suggestions, but I think we could try to add a "history" section and an "applications" section.

About history: I think this group is one of the most popular booktext-examples of non-abelian groups and it virtually appears in all Group Theory basic texts. However, I have never found even a brief summary of the history and origin of this group. It could be a significant improvement of the article.

Does anybody know a good reference for this? ¡Add it here! I personally don't.

About applications: this group is of great importance of quantum computation in the field of quantum algorithms. This is a topic I know quite well, but I does not make a section itself.

Does anybody know more applications of the dihedral group in science? If we had some more we could put them together.

Garrapito (talk) 18:04, 16 November 2011 (UTC)

Equivalent definitions
(third)

The semidirect product of cyclic groups Zn and Z2, with Z2 acting on Zn by inversion (thus, Dihn always has a normal subgroup isomorphic to the group Zn

Right prentesize is missing... Jumpow (talk) 11:03, 11 January 2013 (UTC) Jumpow

Snowflakes
According to the relevant Wikipedia page, only a tiny fraction of snowflakes have sixfold symmetry. (And even then it seems to be approximate, as far as I can tell.) So, while the picture at the top of this page is pretty, it's extremely misleading... I'm going to remove it. — Preceding unsigned comment added by 131.111.184.88 (talk) 22:30, 26 July 2013 (UTC)

Automorphism group
The article says "The automorphism group of Dihn is isomorphic to the affine group Aff(Z/nZ) $$=\{ax + b \mid (a,n) = 1\}$$", but this is a more general notion of an affine group than the definition in the article Affine group, where there is only question of vector spaces. In fact, the group $$=\{ax + b \mid (a,n) = 1\}$$ is the holomorph of Z/nZ, thus the automorphism group of Dihn is isomorphic to the holomorph of Z/nZ. Marvoir (talk) 14:39, 18 January 2014 (UTC)

Notation and font use
I notice some recent edits by away from the general notation (especially font use) for groups on WP. In particular:
 * Groups names, e.g. Z2 are in roman font - they are symbol, not variables. See:
 * WP:Manual of Style/Mathematics: "The abstract cyclic group of order n, when written additively, has notation Zn, or in contexts where there may be confusion with p-adic integers, Z/nZ; when written multiplicatively, e.g. as roots of unity, Cn is used (this does not affect the notation of isometry groups called Cn)." There is no possibility of the mentioned confusion, and use of ring names (Z in this instance) seems like a confusion of disciplines in the purely group context. Note the lack of italics on the group names. I am aware that many papers and publications do use italics, but here the MoS applies.  Note too that the bold Zn generally refers to the ring rather than to the group.
 * WP:Manual of Style/Mathematics: "To start with, we generally use italic text for variables, but never for numbers or symbols"

Further, reverting another editor's edits without an edit summary is kind of, well, saying that the reverted edit it was so blatantly bad as to be beneath explanation for a revert, such as for vandalism; i.e., it can be interpreted as insulting. Please refrain from summaryless reverts. —Quondum 16:40, 10 April 2015 (UTC)

Assessment comment
Substituted at 02:00, 5 May 2016 (UTC)

Sentence that does not mean anything:
In the section Examples of automorphism groups, this sentence appears as follows:

"Compare the values 6 and 4 for Euler's totient function, the multiplicative group of integers modulo n for n = 9 and 10, respectively. ".

I hope someone knowledgeable about the dihedral group will fix this, so that it means something.2600:1700:E1C0:F340:1147:130B:19C6:51FB (talk) 18:12, 4 February 2019 (UTC)

Intro sentence
The intro says: "Dihedral groups are among the simplest examples of finite groups, and they play an important role in group theory, geometry, and chemistry." This was added in 2007, by an editor apparently no longer active. The chemistry claim seems dubious -- and yet I can imagine a chemist telling us something persuasive to the effect that this is real. Not being a chemist, I can only search, and find lots of pages about dihedral groups which have copied this text from WP, and lots of pages about chemistry which talk about dihedral angles and alkyl or other groups, but these are not mathematical groups, let alone dihedral ones. ¶ Can anyone see a reason to have "chemistry" here? I think perhaps the whole sentence could be deleted, since the only real content is "geometry"; after all, dihedral groups are important in group theory like molecules are important in chemisty. Imaginatorium (talk) 04:17, 21 April 2020 (UTC)

Dihn
How to pronounce this word 2001:4455:2D8:F500:68:F270:CBA:747C (talk) 08:09, 15 November 2022 (UTC)

 * There's no "word" Dihn on the page, only the abbreviation "Dih" (for dihedral) with an associated number ("n" as a generalization if there's no specific number). Probably "Dihedral group of order n" or "Dihedral group of the nth order... AnonMoos (talk) 14:44, 16 November 2022 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Dihedral group


text:
Dou Xian

Dou Xian (died c. August 92 ) was a Chinese general and consort kin of the Eastern Han dynasty, famous for destroying the Xiongnu nomadic empire.

Early life
A native of modern-day Xianyang, Shaanxi Province, he was part of the powerful Dou clan which dominated court politics during his tenure. However, his father Dou Xun fell into disgrace and died in 70 AD, leaving Dou Xian an orphan. His fortunes were greatly enhanced, though, when his two sisters entered the imperial harem in 77. In the following year, the older of these two sisters became Empress Zhangde, the wife of Emperor Zhang of Han, and lasted briefly as empress dowager and regent during the early reign of Emperor He of Han. The biography of Dou Xian can be found in Chapter LIII of the Hou Hanshu.

Campaigns against the Xiongnu
In 89 AD, Dou Xian led a Han expedition against the Northern Xiongnu. The army advanced from Jilu, Manyi, and Guyang in three great columns. In the summer of 89, the forces—comprising a total of 40,000 troops—assembled at Zhuoye Mountain. Near the end of the campaign, Dou's forces chased the Northern Chanyu into the Altai Mountains, killing 13,000 Xiongnu and accepting the surrender of 200,000 Xiongnu from 81 tribes. A light cavalry of 2000 was sent towards the Xiongnu at Hami, capturing the region from them. Dou Xian marched with his troops in a triumphal progress to the heartland of the Northern Xiongnu's territory and engraved an inscription commemorating the victory on Mount Yanran, before returning to Han. The Han victory in the campaign of 89 AD resulted in the destruction of the Xiongnu state.

In 90 AD, Dou Xian had encamped at Wuwei. He sent Deputy Colonel Yan Pan with 2000 light cavalry to strike down the final Xiongnu defenses in the Western Regions, capturing Yiwu and receiving the surrender of Jushi. Major Liang Feng was dispatched to capture the Northern Chanyu, which he did, but he was forced to leave him behind as Dou Xian had already broken camp and returned to China. In the tenth month of 90 AD, Dou Xian sent Liang Feng and Ban Gu to help the Northern Chanyu make preparations for his planned travel as he wished to submit to the Han court in person the following month.

However, this never came to be as Dou Xian dispatched General Geng Kui and Shizi of the Southern Xiongnu with 8000 light cavalry to attack the Northern Chanyu, encamped at Heyun (河雲), in 90 AD. Once the Han forces arrived at Zhuoye Mountains, they left their heavy equipment behind to launch a swift pincer movement towards Heyun. Geng Kui attacked from the east via the Khangai Mountains and Ganwei River (甘微河), while Shizi attacked from the west via the Western Lake (西海). The Northern Chanyu—said to be greatly shocked by this—launched a counterattack, but he was forced to flee as he left his family and seal behind. The Han killed 8000 men and captured several thousands. In 91 AD, General Geng Kui and Major Ren Shang with a light cavalry of 800 advanced further via the Juyan Gol (Juyansai) into the Altai Mountains, where the Northern Chanyu had encamped. At the Battle of Altai Mountains, they massacred 5000 Xiongnu men and pursued the Northern Chanyu until he escaped to an unknown place. By 91 AD, the last remnants of the Northern Xiongnu had migrated west towards the Ili River valley.

Downfall
In 92, the Dous suddenly fell from grace as the result of a coup d'état. The details are unclear now, but it appeared that Emperor He, perhaps encouraged by his brother Prince Qing (whose mother had died at the Dous' hand and whose status as crown prince had been stripped away by their machinations) and the eunuch Zheng Zhong (鄭眾), made sudden orders to the imperial guards to have them arrest Dou Xian's associates and execute them. He sent Dou Xian and his brothers back to their marches, but eventually ordered them to commit suicide, with the exception of Dou Gui. Empress Dowager Dou remained empress dowager, but lost all power.

Inscription of Yanran
The Inscription of Yanran, composed by Ban Gu and engraved on Mount Yanran to commemorate Dou Xian's victory against the Xiongnu, was recorded in the 5th-century Book of Later Han. The expression "to carve a stone on Yanran" entered the Chinese language as a synonym for achieving a decisive victory. In 2016, a researchers team of Mongolian national university expedition rediscovered the inscription in the Inil (Delgerkhangai) Mountains in southern Mongolia". The 220 legible characters of the inscription, out of a total of 260, are identical to the text recorded in the Book of the Later Han.

title: Dou Xian


text:
User:HollyAm

Hey there
My name is Holly. I am a 2X-year-old student at Somewhere University and an administrative assistant at Some Place College. I was born and raised in Milwaukee, currently living in Chicagoland.

I have been a registered Wikipedian since October 2002. I edited for a while, but then I guess I either forgot about this place or became busy with other things. I returned in May 2005 and found that Wikipedia was a lot different than how I left it: now there are categories, templates, and a Recent Changes page that fills up faster than you can blink.

As a displaced Wisconsinite, I participate in WikiProject Wisconsin. I also help with stub sorting, categorizing, wikifying, copyediting, and the like.

Articles created
Here are some articles (stubs) that I have started: Abner Kirby, Albert G. Schmedeman, Bean Station, Tennessee, Benedictine University, Byron Kilbourn, Cardinal Stritch University, Edward Scofield, George H. Walker, George Wilbur Peck, Gerhard A. Bading, Gladys Porter Zoo, Grand Pre, Nova Scotia, H. L. Davis, Harrison Ludington, Harrogate, Tennessee, Henry W. Maier, Homer Glen, Illinois, Horace Chase, I (album), Isaac P. Walker, Isaac Stephenson, James Kilbourne, James O. Davidson, James S. Brown, James T. Lewis, Jesse White (actor), Jesse White (politician), Jim Doyle (Canadian politician), John Black (Wisconsin politician), John Bohn, John C. Koch, John R. Quinn, John W. Reynolds, Joseph V. Quarles, Leonard J. Farwell, Louis P. Harvey, Lucius Fairchild, Martin J. Schreiber, Pee Wee King, Philetus Sawyer, Sherburn M. Becker, St. Augusta, Minnesota, The Real World, U.S. Bank Center, Whynot, Mississippi, William C. Rauschenberger, William E. Smith, William H. Upham, William Pitt Lynde, William R. Taylor (politician)

title: User:HollyAm


text:
Bonnie Raitt

Bonnie Lynn Raitt (born November 8, 1949) is an American blues rock singer, guitarist, and songwriter. In 1971, Raitt released her self-titled debut album. Following this, she released a series of critically acclaimed roots-influenced albums that incorporated elements of blues, rock, folk, and country. She was also a frequent session player and collaborator with other artists, including Warren Zevon, Little Feat, Jackson Browne, the Pointer Sisters, John Prine, and Leon Russell.

In 1989, after several years of limited commercial success, she had a major hit with her tenth studio album, Nick of Time, which included the song of the same name. The album reached number one on the Billboard 200 chart, and won the Grammy Award for Album of the Year. It has since been selected by the Library of Congress for preservation in the United States National Recording Registry. Her following two albums, Luck of the Draw (1991) and Longing in Their Hearts (1994), were multimillion sellers, generating several hit singles, including "Something to Talk About", "Love Sneakin' Up On You", and the ballad "I Can't Make You Love Me" (with Bruce Hornsby on piano). Her 2022 single "Just Like That" won the Grammy Award for Song of the Year.

As of 2023, Raitt has received 13 competitive Grammy Awards, from 30 nominations, as well as a Grammy Lifetime Achievement Award. She ranked No. 50 on Rolling Stone's list of the "100 Greatest Singers of All Time" and ranked No. 89 on the magazine's list of the "100 Greatest Guitarists of All Time." Australian country music artist Graeme Connors has said "Bonnie Raitt does something with a lyric no one else can do; she bends it and twists it right into your heart."

In 2000, Raitt was inducted into the Rock and Roll Hall of Fame. She has received the Icon Award from the Billboard Women in Music Awards and the MusiCares Person of the Year Award from The Recording Academy.

Early life
Bonnie Lynn Raitt was born on November 8, 1949, in Burbank, California. Her mother, Marge Goddard (née Haydock), was a pianist, and her father, John Raitt, was an actor in musical productions such as Oklahoma! and The Pajama Game. Raitt is of Scottish ancestry; her ancestors constructed Rait Castle near Nairn. As a child, Raitt would often play with her two brothers, Steve and David and was a self-described tomboy. John Raitt's job as a theater actor meant Bonnie did not interact with him as much as she would have liked. Raitt grew to resent her mother, as she became the main authority figure of the household whenever John was away.

Raitt's musically inclined parents had a strong influence on her life. From a young age, she and her brothers were encouraged to pursue music. Initially, Raitt played the piano but was intimidated by her mother's abilities. She instead began playing a Stella guitar, which she received as a Christmas gift in 1957 at the age of eight. Raitt did not take lessons; she was instead influenced by the American folk music revival of the 1950s. She was also influenced by the beatnik movement, stating "It represented my whole belief [...] I'd grow my hair real long so I looked like a beatnik."

From ages eight through fifteen, Raitt and her brothers attended a summer camp in the Adirondack Mountains called Camp Regis. It was there where Raitt learned of her musical talents, when camp counselors would ask her to play in front of the campers. Learning how to play songs from folk albums then became a hobby for Raitt. As a teenager, Raitt was self-conscious about her weight and her freckles, and saw music as an escape from reality. "That was my saving grace. I just sat in my room and played my guitar," said Raitt.

After graduating from Oakwood Friends School in Poughkeepsie, New York in 1967, Raitt entered Radcliffe College of Harvard University, majoring in Social Relations and African studies. She said her "plan was to travel to Tanzania, where President Julius Nyerere was creating a government based on democracy and socialism". She was the lead singer in a campus music group called the "Revolutionary Music Collective" founded by songwriter Bob Telson which played for striking Harvard students during the Student strike of 1970. Raitt befriended blues promoter Dick Waterman. During her second year of college, Raitt left school for a semester and moved to Philadelphia with Waterman and other local musicians. Raitt said it was an "opportunity that changed everything."

1970–1976
In the summer of 1970, she played with her brother David on stand-up bass with Mississippi Fred McDowell at the Philadelphia Folk Festival as well as opening for John Hammond at the Gaslight Cafe in New York. She was seen by a reporter from Newsweek, who began to spread the word about her performance. Scouts from major record companies were soon attending her shows to watch her play. She eventually accepted an offer from Warner Bros., who soon released her debut album, Bonnie Raitt, in 1971. The album was warmly received by the music press, with many writers praising her skills as an interpreter and as a bottleneck guitarist; at the time, few women in popular music had strong reputations as guitarists.

While admired by those who saw her perform, and respected by her peers, Raitt gained little public acclaim for her work. Her critical stature continued to grow but record sales remained modest. Her second album, Give It Up, was released in 1972 to positive reviews. One journalist described the album as "an excellent set" and "established the artist as an inventive and sympathetic interpreter". However, it did not change her commercial fortunes. 1973's Takin' My Time was also met with critical acclaim, but these notices were not matched by the sales.

Raitt began to receive greater press coverage, including a 1975 cover story for Rolling Stone, but with 1974's Streetlights, reviews for her work were becoming increasingly mixed. By this point, Raitt was already experimenting with different producers and different styles, and she began to adopt a more mainstream sound that continued through 1975's Home Plate. In 1976, Raitt made an appearance on Warren Zevon's eponymous album.

She was influenced by the playing style of Lowell George, of the band Little Feat, particularly his use of a pre-amp compressor with a slide guitar. B.B. King once called Raitt the "best damn slide player working today".

1977–1988
1977's Sweet Forgiveness album gave Raitt her first commercial breakthrough, when it yielded a hit single in her remake of "Runaway". Recast as a heavy rhythm and blues recording based on a rhythmic groove inspired by Al Green, Raitt's version of "Runaway" was disparaged by many critics. However, the song's commercial success prompted a bidding war for Raitt between Warner Bros. and Columbia Records. "There was this big Columbia–Warner war going on at the time", recalled Raitt in a 1990 interview. "James Taylor had just left Warner Bros. and made a big album for Columbia... And then, Warner signed Paul Simon away from Columbia, and they didn't want me to have a hit record for Columbia – no matter what! So, I renegotiated my contract, and they basically matched Columbia's offer. Frankly the deal was a really big deal."

Warner Brothers held higher expectations for Raitt's next album, The Glow, in 1979, but it was released to poor reviews as well as modest sales. Raitt had one commercial success in 1979 when she helped organize the five concerts of Musicians United for Safe Energy (MUSE) at Madison Square Garden in New York City. Those shows spawned the three-record gold album No Nukes, as well as a Warner Brothers feature film of the same name, and featured co-founders Jackson Browne, Graham Nash, John Hall, and Raitt as well as Bruce Springsteen, Tom Petty and the Heartbreakers, the Doobie Brothers, Carly Simon, James Taylor, Gil Scott-Heron, and others.

In 1980, she appeared as herself in the Paramount film Urban Cowboy where she sang "Don't It Make You Wanna Dance".

For her next record, 1982's Green Light, Raitt made a conscious attempt to revisit the sound of her earlier records. However, to her surprise, many of her peers and the media compared her new sound to the burgeoning new wave movement. The album received her strongest reviews in years, but her sales did not improve and this had a severe impact on her relationship with Warner Brothers.

Tongue and Groove and release from Warner Brothers
In 1983, Raitt was finishing work on her follow-up album, Tongue and Groove. The day after mastering was completed on Tongue & Groove, the record company dropped Raitt from its roster, not being happy with her commercial performance up to that point. The album was shelved and not released, and Raitt was left without a record contract. At this time Raitt was also struggling with alcohol and drug abuse problems.

Despite her personal and professional problems, Raitt continued to tour and participate in political activism. In 1985, she sang and appeared in the video of "Sun City", the anti-apartheid song written and produced by guitarist Steven Van Zandt. Along with her participation in Farm Aid and Amnesty International concerts, Raitt traveled to Moscow, Russia in 1987 to participate in the first joint Soviet/American Peace Concert, later shown on the Showtime cable network. Also in 1987, Raitt organized a benefit in Los Angeles for Countdown '87 to Stop Contra Aid. The benefit featured herself, along with Don Henley, Herbie Hancock, and others.

Two years after Warner Brothers Records dropped Raitt from their label, they notified her of their plans to release the Tongue and Groove album. "I said it wasn't really fair," recalled Raitt. "I think at this point they felt kind of bad. I mean, I was out there touring on my savings to keep my name up, and my ability to draw was less and less. So they agreed to let me go in and recut half of it, and that's when it came out as Nine Lives." That album, released in 1986 to critical and commercial disappointment, was Raitt's last new recording for Warner Brothers.

In late 1987, Raitt joined singers k.d. lang and Jennifer Warnes as background vocalists for Roy Orbison's television special, Roy Orbison and Friends, A Black and White Night. Following this highly acclaimed broadcast, Raitt began working on new material. By then, she was clean and sober, having resolved her problems with substance abuse. She later credited Stevie Ray Vaughan for his help in a Minnesota State Fair concert the night after Vaughan's 1990 death. During this time, Raitt considered signing with the Prince-owned Paisley Park Records, but they could not come to an agreement and negotiations fell through. Instead, she began recording a bluesy mix of pop and rock songs under the production guidance of Don Was at Capitol Records.

Raitt had met Was through Hal Willner, who was putting together Stay Awake, a tribute album to Disney music for A&M. Was and Willner both wanted Raitt to sing lead on an adult-contemporary arrangement created by Was for "Baby Mine", the lullaby from Dumbo. Raitt was very pleased with the sessions, and she asked Was to produce her next album.

1989–1999: Commercial breakthrough
After working with Was on the Stay Awake album, Raitt's management, Gold Mountain, approached numerous labels about a new record deal and found interest from Capitol Records. Raitt was signed to Capitol by A&R executive Tim Devine. With her first Capitol Records release, and after nearly twenty years in the business, Raitt achieved commercial success with Nick of Time, her tenth overall album of her career. Released in the spring of 1989, Nick of Time went to number one on the U.S. album chart following Raitt's Grammy sweep in early 1990. This album has also been voted number 230 in the Rolling Stone list of 500 Greatest Albums of All Time. Raitt later stated that her 10th try was "my first sober album."

At the same time, Raitt received a fourth Grammy Award for her duet "I'm in the Mood" with John Lee Hooker on his album The Healer. Nick of Time was also the first of many of her recordings to feature her longtime rhythm section of Ricky Fataar and James "Hutch" Hutchinson (although previously Fataar had played on her Green Light album and Hutchinson had worked on Nine Lives), both of whom continue to record and tour with her. Since its release in 1989, Nick of Time has currently sold over five million copies in the US alone.

Raitt followed up this success with three more Grammy Awards for her next album, 1991's Luck of the Draw, which sold seven million copies in the United States. Three years later, in 1994, she added two more Grammys with her album Longing in Their Hearts, her second number one album, that sold two million copies in the US. Raitt's collaboration with Don Was amicably came to an end with 1995's live release Road Tested. Released to solid reviews, it was certified gold in the US.

"Rock Steady" was a hit written by Bryan Adams and Gretchen Peters in 1995. The song was written as a duet with Bryan Adams and Bonnie Raitt for her Road Tested tour, which also became one of her albums. The original demo version of the song appears on Adams' 1996 single "Let's Make a Night to Remember".

For her next studio album, Raitt hired Mitchell Froom and Tchad Blake as her producers. "I loved working with Don Was but I wanted to give myself and my fans a stretch and do something different," Raitt stated. Her work with Froom and Blake was released on Fundamental in 1998.

2000–2007
In March 2000, Raitt was inducted into the Rock and Roll Hall of Fame in Cleveland, Ohio. Silver Lining was released in 2002. In the US, it reached number 13 on the Billboard chart and was later certified Gold. It contains the singles "I Can't Help You Now", "Time of Our Lives", and the title track. All three singles charted within the top 40 of the US Adult Contemporary chart.

On March 19, 2002, Bonnie Raitt received a star on the Hollywood Walk of Fame for her contributions to the recording industry, located at 1750 N. Vine Street. In 2003 Capitol Records released the compilation album The Best of Bonnie Raitt. It contains songs from her prior Capitol albums from 1989 to 2002 including Nick of Time, Luck of the Draw, Longing in Their Hearts, Road Tested, Fundamental, and Silver Lining. Raitt was featured on the album True Love by Toots and the Maytals, which won the Grammy Award in 2004 for Best Reggae Album.

Souls Alike was released in September 2005. In the US, it reached the top 20 on the Billboard chart. It contains the singles "I Will Not Be Broken" and "I Don't Want Anything to Change", which both charted in the top 40 of the US Adult Contemporary chart. In 2006, she released the live DVD/CD Bonnie Raitt and Friends, which was filmed as part of the critically acclaimed VH1 Classic Decades Rock Live! concert series, featuring special guests Keb' Mo', Alison Krauss, Ben Harper, Jon Cleary, and Norah Jones. The DVD was released by Capitol Records on August 15. Bonnie Raitt and Friends, which was recorded live in Atlantic City, NJ on September 30, 2005, features never-before-seen performance and interview footage, including four duets not included in the VH1 Classic broadcast of the concert. The accompanying CD features 11 tracks, including the radio single "Two Lights in the Nighttime" (featuring Ben Harper). In 2007, Raitt contributed to Goin' Home: A Tribute to Fats Domino. With Jon Cleary, she sang a medley of "I'm in Love Again" and "All by Myself" by Fats Domino.

Raitt is interviewed on screen and appears in performance footage in the 2005 documentary film Make It Funky!, which presents a history of New Orleans music and its influence on rhythm and blues, rock and roll, funk and jazz. In the film, Raitt performs "What is Success" with Allen Toussaint and band, a song he wrote and that Raitt included on her 1974 album Streetlights.

2008–present
Raitt appeared on the June 7, 2008 broadcast of Garrison Keillor's radio program A Prairie Home Companion. She performed two blues songs with Keb' Mo': "No Getting Over You" and "There Ain't Nothin' in Ramblin'". Raitt also sang "Dimming of the Day" with Richard Thompson. This show, along with another one with Raitt and her band in October 2006, is archived on the Prairie Home Companion website. Raitt appeared in the 2011 documentary Reggae Got Soul: The Story of Toots and the Maytals, which was featured on the BBC and described as "The untold story of one of the most influential artists ever to come out of Jamaica".

In February 2012, Raitt performed a duet with Alicia Keys at the 54th Annual Grammy Awards in 2012 honoring Etta James. In April 2012, Raitt released her first studio album since 2005, entitled Slipstream. It charted at Number 6 on the US Billboard 200 chart marking her first top ten album since 1994's Longing in Their Hearts. The album was described as "one of the best of her 40-year career" by American Songwriter magazine. In September 2012, Raitt was featured in a campaign called "30 Songs / 30 Days" to support Half the Sky: Turning Oppression into Opportunity for Women Worldwide, a multi-platform media project inspired by a project outlined in a book by Nicholas Kristof and Sheryl WuDunn. In 2013, she appeared on Foy Vance's album ''Joy of Nothing. ''

On May 30, 2015, Leon Russell, Bonnie Raitt and Ivan Neville gave a performance at The Canyon Club in Agoura Hills, California to raise cash for Marty Grebb who was battling cancer. Grebb had played on some of their albums.

In February 2016, Raitt released her seventeenth studio album Dig In Deep. The album charted at number 11 on the US Billboard 200 chart and received favorable reviews. The album features the single "Gypsy in Me" as well as a cover of the INXS song "Need You Tonight". Raitt cancelled the first leg of her 2018 spring-summer touring schedule due to a recently discovered medical issue requiring surgical intervention. She reported that a "full recovery" is expected and that she planned to resume touring with already-scheduled dates in June 2018.

In 2022, Raitt announced the title of her 21st studio album would be Just Like That.... The record was released on April 22, 2022, and coincided with the beginning of a nationwide tour that ran through November 2022. Preceding the album, Raitt released "Made Up Mind", a song originally written by Canadian roots duo The Bros. Landreth, as the lead single. The title track of the album won for Song of the Year at the 65th Annual Grammy Awards in February 2023. The song also won in the Best American Roots Song category.

Artistry
Raitt possesses a contralto vocal range. Music journalist Robert Christgau described Raitt's voice as not particularly beautiful but "textured", capable of shouting, crooning, "carry[ing] a tune or fill[ing] a room". Christgau likened her vocal style to "a loving woman who has the touch, soft and hard at the right times in the right places". Journalist Will Hermes described Raitt's voice as warm and precise. Describing her as a "master interpreter of other writers’ songs", Chris Hansen Orf of The Arizona Republic note that Raitt is equally skilled at singing blues, folk, country, rock and pop music. Kevin McKeough of the Chicago Tribune observed that blues has "remained the bedrock of all of Raitt's musical excursions", with her voice alternating between "sigh to a call to a sustained cry". Discussing the ability of a singer to make use of her voice, singer Linda Ronstadt stated "Of my own peers, Bonnie Raitt has way more musicianship than I do." Singer and guitarist David Crosby has said that Raitt is his favorite singer of all time.

Personal life
Raitt has taken sabbaticals, including after the deaths of her parents, brother, and best friend. She has said "When I went through a lot of loss, I took a hiatus." Raitt and actor Michael O'Keefe were married on April 27, 1991. They announced their divorce on November 9, 1999, with a factor appearing to be that their careers caused considerable time apart.

Drug and alcohol use and recovery
Raitt was a user of alcohol and drugs, but began psychotherapy and joined Alcoholics Anonymous in the late 1980s. "I thought I had to live that partying lifestyle in order to be authentic," she said, "but in fact if you keep it up too long, all you're going to be is sloppy or dead." She has been sober since 1987. She has credited Stevie Ray Vaughan for breaking her substance abuse, saying that what gave her the courage to admit her alcohol problem and stop drinking was seeing that Vaughan was an even better musician when sober. She has also said that she stopped because she realized that the "late night life" was not working for her. In 1989, she said, "I really feel like some angels have been carrying me around. I just have more focus and more discipline, and consequently more self-respect."

Political activism

Raitt's political involvement goes back to the early 1970s. Her 1972 album Give It Up had a dedication "to the people of North Vietnam ..." printed on the back. Raitt's web site urges fans to learn more about preserving the environment. She was a founding member of Musicians United for Safe Energy in 1979 and a catalyst for the larger anti-nuclear movement, becoming involved with groups like the Abalone Alliance and Alliance for Survival. In 1994 at the urging of Dick Waterman, Raitt funded the replacement of a headstone for one of her mentors, blues guitarist Fred McDowell through the Mt. Zion Memorial Fund. Raitt later financed memorial headstones in Mississippi for musicians Memphis Minnie, Sam Chatmon, and Tommy Johnson again with the Mt. Zion Memorial Fund.

In 2002, Raitt signed on as an official supporter of Little Kids Rock, a nonprofit organization that provides free musical instruments and free lessons to children in public schools throughout the U.S. She has visited children in the program and sits on the organization's board of directors as an honorary member.

At the Stockholm Jazz Festival in July 2004, Raitt dedicated a performance of "Your Good Thing (Is About to End)", from her 1979 album The Glow, to sitting (and later re-elected) U.S. President George W. Bush. She was quoted as saying "We're gonna sing this for George Bush because he's out of here, people!".

In 2008, Raitt donated a song to the Aid Still Required's CD to assist with relief efforts in Southeast Asia from the 2004 tsunami. Raitt worked with Reverb, a non-profit environmental organization, for her 2005 fall/winter and 2006 spring/summer/fall tours. Raitt is part of the No Nukes group, which opposes the expansion of nuclear power. In 2007, No Nukes recorded a music video of a new version of the Buffalo Springfield song "For What It's Worth". During the 2008 Democratic primary campaign, Raitt, along with Jackson Browne and bassist James "Hutch" Hutchinson, performed at campaign appearances for candidate John Edwards.

During the 2016 Democratic primary campaign, Raitt endorsed Vermont Senator Bernie Sanders.

Discography

 * Bonnie Raitt (1971)
 * Give It Up (1972)
 * Takin' My Time (1973)
 * Streetlights (1974)
 * Home Plate (1975)
 * Sweet Forgiveness (1977)
 * The Glow (1979)
 * Green Light (1982)
 * Nine Lives (1986)
 * Nick of Time (1989)
 * Luck of the Draw (1991)
 * Longing in Their Hearts (1994)
 * Fundamental (1998)
 * Silver Lining (2002)
 * Souls Alike (2005)
 * Slipstream (2012)
 * Dig In Deep (2016)
 * Just Like That... (2022)

Guitar
Raitt's principal touring guitar is a customized Fender Stratocaster that she nicknamed Brownie. This became the basis for a signature model in 1996. Raitt was the first female musician to receive a signature Fender line.

"My brown Strat—the body is a '65 and the neck is from some time after that. It's kind of a hybrid that I got for $120 at 3 o' clock in the morning in 1969. It's the one without the paint, and I've used that for every gig since 1969."

Awards

 * Grammy Awards

†: Not a Grammy Award, but awarded by The Recording Academy
 * 1980
 * "You're Gonna Get What's Coming"
 * rowspan="3"|Best Female Rock Vocal Performance
 * Nominated
 * 1983
 * "Green Light"
 * Nominated
 * 1987
 * "No Way to Treat a Lady"
 * Nominated
 * rowspan="4"| 1990
 * rowspan="2"|Nick of Time
 * Album of the Year
 * Won
 * Best Female Rock Vocal Performance
 * Won
 * "Nick of Time"
 * Best Female Pop Vocal Performance
 * Won
 * "I'm in the Mood" (with John Lee Hooker)
 * Best Traditional Blues Recording
 * Won
 * rowspan="6"| 1992
 * rowspan="2"|Luck of the Draw
 * Album of the Year
 * Nominated
 * Best Rock Vocal Solo Performance
 * Won
 * rowspan="2"|"Something to Talk About"
 * Record of the Year
 * Nominated
 * Best Female Pop Vocal Performance
 * Won
 * "Good Man, Good Woman"
 * Best Rock Performance by a Duo or Group With Vocal
 * Won
 * Bonnie Raitt
 * MusiCares Person of the Year†
 * Won
 * rowspan="5"| 1995
 * rowspan="2"|Longing in Their Hearts
 * Album of the Year
 * Nominated
 * Best Pop Vocal Album
 * Won
 * rowspan="2"|"Love Sneakin' Up On You"
 * Record of the Year
 * Nominated
 * Best Female Rock Vocal Performance
 * Nominated
 * "Longing in Their Hearts"
 * Best Female Pop Vocal Performance
 * Nominated
 * 1996
 * "You Got It"
 * Best Female Pop Vocal Performance
 * Nominated
 * rowspan="3"|1997
 * Road Tested
 * Best Rock Album
 * Nominated
 * "Burning Down the House"
 * Best Female Rock Vocal Performance
 * Nominated
 * "SRV Shuffle"
 * Best Rock Instrumental Performance
 * Won
 * 1999
 * "Kisses Sweeter Than Wine" (with Jackson Browne)
 * Best Pop Collaboration with Vocals
 * Nominated
 * 2003
 * "Gnawin' on It"
 * rowspan="2"|Best Female Rock Vocal Performance
 * Nominated
 * 2004
 * "Time of Our Lives"
 * Nominated
 * 2006
 * "I Will Not Be Broken"
 * Best Female Pop Vocal Performance
 * Nominated
 * 2013
 * Slipstream
 * Best Americana Album
 * Won
 * 2022
 * Herself
 * Grammy Lifetime Achievement Award
 * Won
 * 1999
 * "Kisses Sweeter Than Wine" (with Jackson Browne)
 * Best Pop Collaboration with Vocals
 * Nominated
 * 2003
 * "Gnawin' on It"
 * rowspan="2"|Best Female Rock Vocal Performance
 * Nominated
 * 2004
 * "Time of Our Lives"
 * Nominated
 * 2006
 * "I Will Not Be Broken"
 * Best Female Pop Vocal Performance
 * Nominated
 * 2013
 * Slipstream
 * Best Americana Album
 * Won
 * 2022
 * Herself
 * Grammy Lifetime Achievement Award
 * Won
 * 2022
 * Herself
 * Grammy Lifetime Achievement Award
 * Won
 * Won
 * rowspan="4"| 2023
 * rowspan="2"| "Just Like That"
 * Song of the Year
 * Won
 * Best American Roots Song
 * Won
 * Just Like That...
 * Best Americana Album
 * Nominated
 * "Made Up Mind"
 * Best Americana Performance
 * Won
 * }
 * Best Americana Performance
 * Won
 * }

 * Americana Music Honors and Awards

 * 2012
 * Herself
 * Lifetime Achievement Award for Performance
 * Won
 * 2016
 * Herself
 * Artist of the Year
 * Nominated
 * 2023
 * "Just Like That"
 * Song of the Year
 * Won
 * }
 * Song of the Year
 * Won
 * }

 * Rock and Roll Hall of Fame

 * 2000
 * Herself
 * Hall of Fame induction
 * Won
 * }
 * }

 * Other awards
 * In 1992, Raitt was awarded an Honorary Doctorate of Music from Berklee College of Music.
 * In 1997, Raitt was awarded the Harvard Arts Medal.
 * In 2017, Raitt was honored with a Lifetime Achievement Award from the National Guitar Museum.
 * In 2018, Raitt received the People's Voice Award from the Folk Alliance International Awards in recognition of her activism.
 * In 2022, Raitt received the Icon Award at the Billboard Women in Music Awards.

title: Bonnie Raitt


text:
National Medal of Science

The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social sciences, biology, chemistry, engineering, mathematics and physics. The twelve member presidential Committee on the National Medal of Science is responsible for selecting award recipients and is administered by the National Science Foundation (NSF).

History
The National Medal of Science was established on August 25, 1959, by an act of the Congress of the United States under. The medal was originally to honor scientists in the fields of the "physical, biological, mathematical, or engineering sciences". The Committee on the National Medal of Science was established on August 23, 1961, by executive order 10961 of President John F. Kennedy.

On January 7, 1979, the American Association for the Advancement of Science (AAAS) passed a resolution proposing that the medal be expanded to include the social and behavioral sciences. In response, Senator Ted Kennedy introduced the Science and Technology Equal Opportunities Act into the Senate on March 7, 1979, expanding the medal to include these scientific disciplines as well. President Jimmy Carter's signature enacted this change as Public Law 96-516 on December 12, 1980.

In 1992, the National Science Foundation signed a letter of agreement with the National Science and Technology Medals Foundation that made the National Science and Technology Medals Foundation the metaorganization over both the National Medal of Science and the very similar National Medal of Technology.

The first National Medal of Science was awarded on February 18, 1963, for the year 1962 by President John F. Kennedy to Theodore von Kármán for his work at the Caltech Jet Propulsion Laboratory. The citation accompanying von Kármán's award reads:

"For his leadership in the science and engineering basic to aeronautics; for his effective teaching and related contributions in many fields of mechanics, for his distinguished counsel to the Armed Services, and for his promoting international cooperation in science and engineering."

The first woman to receive a National Medal of Science was Barbara McClintock, who was awarded for her work on plant genetics in 1970.

The awards ceremony is organized by the Office of Science and Technology Policy. It takes place at the White House and is presided by the sitting United States president.

Although Public Law 86-209 provides for 20 recipients of the medal per year, it is typical for approximately 8–15 accomplished scientists and engineers to receive this distinction each year. There have been a number of years where no National Medals of Science were awarded. Those years include: 1985, 1984, 1980, 1978, 1977, 1972 and 1971.

President Donald J. Trump did not confer any National Medals of Science during his presidency. The last time the medal was awarded before his presidency was on May 19, 2016, when President Barack Obama conferred the 2013 and 2014 medals. On October 23, 2023, President Joe Biden presented nine Medals of Science and 12 National Medals of Technology and Innovation in a ceremony in the East Room of the White House.

Award process
Each year the National Science Foundation sends out a call to the scientific community for the nomination of new candidates for the National Medal of Science. Individuals are nominated by their peers with each nomination requiring three letters of support from individuals in science and technology. Nominations are then sent to the Committee of the National Medal of Science which is a board composed of fourteen presidential appointees comprising twelve scientists, and two ex officio members—the director of the Office of Science and Technology Policy (OSTP) and the president of the National Academy of Sciences (NAS).

According to the Committee, successful candidates must be U.S. citizens or permanent residents who are applying for U.S. citizenship and who have done work of significantly outstanding merit or that has had a major impact on scientific thought in their field. The Committee also values those who promote the general advancement of science and individuals who have influenced science education, although these traits are less important than groundbreaking or thought-provoking research. The nomination of a candidate is effective for three years; at the end of those three years, the candidate's peers are allowed to renominate the candidate. The Committee makes their recommendations to the President for the final awarding decision.

Recipients
Since Caltech professor Theodore von Kármán received the first medal in 1962, a total of 506 medals have been awarded, with just five universities accounting for over 31% of the total. By institutional affiliation at the time of the award, Stanford University counts the most medals at 40, with Harvard University close behind at 35, followed by the University of California, Berkeley at 30, the Massachusetts Institute of Technology at 29, and the California Institute of Technology at 25.

title: National Medal of Science


text:
Talk:Fayette County, Indiana

Demographics
There's got to be a better way to phrase this: "10.20% have a woman whose husband does not live with her" suggests that 10% of all households in the county contain married women who are separated from their husbands. I suspect that it means that 10.20 percent of households contain unmarried, separated, divorced, or widowed adult women. That statement is clear but rather long-winded; is there a shorter standard term? (This presumably would be an issue in lots of similar demographic pages.)Vicki Rosenzweig

Website
new website is http://connersvillecommunity.com/fayette_county

co.fayette.in.us is obsolete 69.174.171.59 (talk)

Fixed. Sbalfour (talk) 17:33, 5 December 2018 (UTC)

redacted material for restoration
On 15 Jan 2015, Yamaguchi redacted 1937 bytes of valid (and verifiable) material from the article with the comment "redacted unsourced claim". No talk page entry supporting the decision to arbitrarily delete some unsourced material from the article, and not other unsourced material was made. I'd rather editors spend their time providing sources for such material as they can, or challenge the factual accuracy of the material in specifics here in the talk page, so that other editors can correct or perhaps replace the material. Deletions that lose material from the encyclopedia are heavily disfavored; the material in question is a good faith edit. I propose restoring the material, sourcing so much of it as I can, and adding a maintenance tag for any material not readily sourced. If Yamaguchi can provide any contrary evidence to the factual accuracy or neutrality of the material deleted, here in the talk page is the right place to say it.Sbalfour (talk) 16:06, 30 August 2015 (UTC)

I've restored the deleted material, and added an "original research" maintenance tag to it. Losing the material is a greater burden in an article that's basically a stub, than waiting for editors to supply citations. If there's a factual validity issue, bring it up here, and let's discuss. I'll look for suitable references as I have time.Sbalfour (talk) 19:25, 30 August 2015 (UTC)

county articles
County articles get short shrift, because every town and city in a county will have its own article, and every event (like a battle, hurricane, drought) that happened in the county will also have its own article. what else is there to say? In particular, a county is a large place, and has a history that in all cases preceded the coming of European settlement and political organization. Its history extends back to the geology of the last ice age before humans appeared on the scene. Hardly ever do I see any of that. Also, a county isn't mostly towns, it's mostly farms, pastures and open space. What about ecology and agronomy? Sbalfour (talk) 17:46, 5 December 2018 (UTC)

title: Talk:Fayette County, Indiana