title: Star

text: With a mass only 80 times that of Jupiter (), 2MASS J0523-1403 is the smallest known star undergoing nuclear fusion in its core. For


title: Star

text: stars with metallicity similar to the Sun, the theoretical minimum mass the star can have and still undergo fusion at the core, is estimated to be about 75 . When the metallicity is very low, the minimum star size seems to be about 8.3% of the solar mass, or about 87 . Smaller bodies called brown dwarfs, occupy a poorly defined grey area between stars and gas giants.


title: Star

text: The combination of the radius and the mass of a star determines its surface gravity. Giant stars have a much lower surface gravity than do main sequence stars, while the opposite is the case for degenerate, compact stars such as white dwarfs. The surface gravity can influence the appearance of a star's spectrum, with higher gravity causing a broadening of the absorption lines.


title: Star

text: The rotation rate of stars can be determined through spectroscopic measurement, or more exactly determined by tracking their starspots. Young stars can have a rotation greater than 100 km/s at the equator. The B-class star Achernar, for example, has an equatorial velocity of about 225 km/s or greater, causing its equator to bulge outward and giving it an equatorial diameter that is more than 50% greater than between the poles. This rate of rotation is just below the critical velocity of 300 km/s at which speed the star would break apart. By contrast, the Sun rotates once every 25–35 days depending on latitude, with an equatorial velocity of 1.93 km/s. A main sequence star's magnetic field and the stellar wind serve to slow its rotation by a significant amount as it evolves on the main sequence.


title: Star

text: Degenerate stars have contracted into a compact mass, resulting in a rapid rate of rotation. However they have relatively low rates of rotation compared to what would be expected by conservation of angular momentum—the tendency of a rotating body to compensate for a contraction in size by increasing its rate of spin. A large portion of the star's angular momentum is dissipated as a result of mass loss through the stellar wind. In spite of this, the rate of rotation for a pulsar can be very rapid. The pulsar at the heart of the Crab nebula, for example, rotates 30 times per second. The rotation rate of the pulsar will gradually slow due to the emission of radiation.


title: Star

text: The surface temperature of a main sequence star is determined by the rate of energy production of its core and by its radius, and is often estimated from the star's color index. The temperature is normally given in terms of an effective temperature, which is the temperature of an idealized black body that radiates its energy at the same luminosity per surface area as the star. The effective temperature is only representative of the surface, as the temperature increases toward the core. The temperature in the core region of a star is several million kelvins.


title: Star

text: The stellar temperature will determine the rate of ionization of various elements, resulting in characteristic absorption lines in the spectrum. The surface temperature of a star, along with its visual absolute magnitude and absorption features, is used to classify a star (see classification below).


title: Star

text: Massive main sequence stars can have surface temperatures of 50,000 K. Smaller stars such as the Sun have surface temperatures of a few thousand K. Red giants have relatively low surface temperatures of about 3,600 K; but they have a high luminosity due to their large exterior surface area.


title: Star

text: The energy produced by stars, a product of nuclear fusion, radiates to space as both electromagnetic radiation and particle radiation. The particle radiation emitted by a star is manifested as the stellar wind, which


title: Star

text: streams from the outer layers as electrically charged protons and alpha and beta particles. A steady stream of almost massless neutrinos emanate directly from the star's core.


title: Star

text: The production of energy at the core is the reason stars shine so brightly: every time two or more atomic nuclei fuse together to form a single atomic nucleus of a new heavier element, gamma ray photons are released from the nuclear fusion product. This energy is converted to other forms of electromagnetic energy of lower frequency, such as visible light, by the time it reaches the star's outer layers.


title: Star

text: The color of a star, as determined by the most intense frequency of the visible light, depends on the temperature of the star's outer layers, including its photosphere. Besides visible light, stars emit forms of electromagnetic radiation that are invisible to the human eye. In fact, stellar electromagnetic radiation spans the entire electromagnetic spectrum, from the longest wavelengths of radio waves through infrared, visible light, ultraviolet, to the shortest of X-rays, and gamma rays. From the standpoint of total energy emitted by a star, not all components of stellar electromagnetic radiation are significant, but all frequencies provide insight into the star's physics.


title: Star

text: Using the stellar spectrum, astronomers can determine the surface temperature, surface gravity, metallicity and rotational velocity of a star. If the distance of the star is found, such as by measuring the parallax, then the luminosity of the star can be derived. The mass, radius, surface gravity, and rotation period can then be estimated based on stellar models. (Mass can be calculated for stars in binary systems by measuring their orbital velocities and distances. Gravitational microlensing has been used to measure the mass of a single star.) With these parameters, astronomers can estimate the age of the star.


title: Star

text: The luminosity of a star is the amount of light and other forms of radiant energy it radiates per unit of time. It has units of power. The luminosity of a star is determined by its radius and surface temperature. Many stars do not radiate uniformly across their entire surface. The rapidly rotating star Vega, for example, has a higher energy flux (power per unit area) at its poles than along its equator.


title: Star

text: Patches of the star's surface with a lower temperature and luminosity than average are known as starspots. Small, "dwarf" stars such as the Sun generally have essentially featureless disks with only small starspots. "Giant" stars have much larger, more obvious starspots, and


title: Star

text: they exhibit strong stellar limb darkening. That is, the brightness decreases towards the edge of the stellar disk. Red dwarf flare stars such as UV Ceti may possess prominent starspot features.


title: Star

text: The apparent brightness of a star is expressed in terms of its apparent magnitude. It is a function of the star's luminosity, its distance from Earth, the extinction effect of interstellar dust and gas, and the altering of the star's light as it passes through Earth's atmosphere. Intrinsic or absolute magnitude is directly related to a star's luminosity, and is the apparent magnitude a star would be if the distance between the Earth and the star were 10 parsecs (32.6 light-years).


title: Star

text: Both the apparent and absolute magnitude scales are logarithmic units: one whole number difference in magnitude is equal to a brightness variation of about 2.5 times (the 5th root of 100 or approximately 2.512). This means that a first magnitude star (+1.00) is about 2.5 times brighter than a second magnitude (+2.00) star, and about 100 times brighter than a sixth magnitude star (+6.00). The faintest stars visible to the naked eye under good seeing conditions are about magnitude +6.


title: Star

text: On both apparent and absolute magnitude scales, the smaller the magnitude number, the brighter the star; the larger the magnitude number, the fainter the star. The brightest stars, on either scale, have negative magnitude numbers. The variation in brightness (Δ"L") between two stars is calculated by subtracting the magnitude number of the brighter star ("m") from the magnitude number of the fainter star ("m"), then using the difference as an exponent for the base number 2.512; that is to say:


title: Star

text: Relative to both luminosity and distance from Earth, a star's absolute magnitude ("M") and apparent magnitude ("m") are not equivalent; for example, the bright star Sirius has an apparent magnitude of −1.44, but it has an absolute magnitude of +1.41.


title: Star

text: The Sun has an apparent magnitude of −26.7, but its absolute magnitude is only +4.83. Sirius, the brightest star in the night sky as seen from Earth, is approximately 23 times more luminous than the Sun, while Canopus, the second brightest star in the night sky with an absolute magnitude of −5.53, is approximately 14,000 times more luminous than the Sun. Despite Canopus being vastly more luminous than Sirius, the latter star appears the brighter of the two. This is because Sirius is merely 8.6 light-years from the Earth, while Canopus is much farther away at a distance of 310 light-years.


title: Star

text: The most luminous known stars have absolute magnitudes of roughly −12, corresponding to 6 million times the luminosity of the Sun. Theoretically, the least luminous stars are at the lower limit of mass at which stars are capable of supporting nuclear fusion of hydrogen in the core; stars just above this limit have been located in the NGC 6397 cluster. The faintest red dwarfs in the cluster are absolute magnitude 15, while a 17th absolute magnitude white dwarf has been discovered.


title: Star

text: The current stellar classification system originated in the early 20th century, when stars were classified from "A" to "Q" based on the strength of the hydrogen line. It was thought that the hydrogen line strength was a simple linear function of temperature. Instead, it was more complicated: it strengthened with increasing temperature, peaked near 9000 K, and then declined at greater temperatures. The classifications were since reordered by temperature, on which the modern scheme is based.


title: Star

text: Stars are given a single-letter classification according to their spectra, ranging from type "O", which are very hot, to "M", which are so cool that molecules may form in their atmospheres. The main classifications in order of decreasing surface temperature are: "O, B, A, F, G, K", and "M". A variety of rare spectral types are given special classifications. The most common of these are types "L" and "T", which classify the coldest low-mass stars and brown dwarfs. Each letter has 10 sub-divisions, numbered from 0 to 9, in order of decreasing temperature. However, this system breaks down at extreme high temperatures as classes "O0" and "O1" may not exist.


title: Star

text: In addition, stars may be classified by the luminosity effects found in their spectral lines, which correspond to their spatial size and is determined by their surface gravity. These range from "0" (hypergiants) through "III" (giants) to "V" (main sequence dwarfs); some authors add "VII" (white dwarfs). Main sequence stars fall along a narrow, diagonal band when graphed according to their absolute magnitude and spectral type. The Sun is a main sequence "G2V" yellow dwarf of intermediate temperature and ordinary size.


title: Star

text: There is additional nomenclature in the form of lower-case letters added to the end of the spectral type to indicate peculiar features of the spectrum. For example, an ""e"" can indicate the presence of emission lines; ""m"" represents unusually strong levels of metals, and ""var"" can mean variations in the spectral type.


title: Star

text: White dwarf stars have their own class that begins with the letter "D". This is further sub-divided into the classes "DA", "DB", "DC", "DO", "DZ", and "DQ", depending on the types of prominent lines found in the spectrum. This is followed by a numerical value that indicates the temperature.


title: Star

text: Variable stars have periodic or random changes in luminosity because of intrinsic or extrinsic properties. Of the intrinsically variable stars, the primary types can be subdivided into three principal groups.


title: Star

text: During their stellar evolution, some stars pass through phases where they can become pulsating variables. Pulsating variable stars vary in radius and luminosity over time, expanding and contracting with periods ranging from minutes to years, depending on the size of the star. This category includes Cepheid and Cepheid-like stars, and long-period variables such as Mira.


title: Star

text: Eruptive variables are stars that experience sudden increases in luminosity because of flares or mass ejection events. This group includes protostars, Wolf-Rayet stars, and flare stars, as well as giant and supergiant stars.


title: Star

text: Cataclysmic or explosive variable stars are those that undergo a dramatic change in their properties. This group includes novae and supernovae. A binary star system that includes a nearby white dwarf can produce certain types of these spectacular stellar explosions, including the nova and a Type 1a supernova. The explosion is created when the white dwarf accretes hydrogen from the companion star, building up mass until the hydrogen undergoes fusion. Some novae are recurrent, having periodic outbursts of moderate amplitude.


title: Star

text: Stars can vary in luminosity because of extrinsic factors, such as eclipsing binaries, as well as rotating stars that produce extreme starspots. A notable example of an eclipsing binary is Algol, which regularly varies in magnitude from 2.1 to 3.4 over a period of 2.87 days.


title: Star

text: The interior of a stable star is in a state of hydrostatic equilibrium: the forces on any small volume almost exactly counterbalance each other. The balanced forces are inward gravitational force and an outward force due to the pressure gradient within the star. The pressure gradient is established by the temperature gradient of the plasma; the outer part of the star is cooler than the core. The temperature at the core of a main sequence or giant star is at least on the order of 10 K. The resulting temperature and pressure at the hydrogen-burning core of a main sequence star are sufficient for nuclear fusion to occur and for sufficient energy to be produced to prevent further collapse of the star.


title: Star

text: As atomic nuclei are fused in the core, they emit energy in the form of gamma rays. These photons interact with the surrounding plasma, adding to the thermal energy at the core. Stars on the main sequence convert hydrogen into helium, creating a slowly but steadily increasing proportion of helium in the core. Eventually the helium content becomes predominant, and energy production ceases at the core. Instead, for stars of more than 0.4 , fusion occurs in a slowly expanding shell around the degenerate helium core.


title: Star

text: In addition to hydrostatic equilibrium, the interior of a stable star will maintain an energy balance of thermal equilibrium. There is a radial temperature gradient throughout the interior that results in a flux of energy flowing toward the exterior. The outgoing flux of energy leaving any layer within the star will exactly match the incoming flux from below.


title: Star

text: The radiation zone is the region of the stellar interior where the flux of energy outward is dependent on radiative heat transfer, since convective heat transfer is inefficient in that zone. In this region the plasma will not be perturbed, and any mass motions will die out. Where this is not the case, then the plasma becomes unstable and convection will occur, forming a convection zone. This can occur, for example, in regions where very high energy fluxes occur, such as near the core or in areas with high opacity (making radiatative heat transfer inefficient) as in the outer envelope.


title: Star

text: The occurrence of convection in the outer envelope of a main sequence star depends on the star's mass. Stars with several times the mass of the Sun have a convection zone deep within the interior and a radiative zone in the outer layers. Smaller stars such as the Sun are just the opposite, with the convective zone located in the outer layers. Red dwarf stars with less than 0.4 are convective throughout, which prevents the accumulation of a helium core. For most stars the convective zones will vary over time as the star ages and the constitution of the interior is modified.


title: Star

text: The photosphere is that portion of a star that is visible to an observer. This is the layer at which the plasma of the star becomes transparent to photons of light. From here, the energy generated at the core becomes free to propagate into space. It is within the photosphere that sun spots, regions of lower than average temperature, appear.


title: Star

text: Above the level of the photosphere is the stellar atmosphere. In a main sequence star such as the Sun, the lowest level of the atmosphere, just above the photosphere, is the thin chromosphere region, where spicules appear and stellar flares begin. Above this is the transition region, where the temperature rapidly increases within a distance of only . Beyond this is the corona, a volume of super-heated plasma that can extend outward to several million kilometres. The existence of a corona appears to be dependent on a convective zone in the outer layers of the star. Despite its high temperature, the corona emits very little light, due to its low gas density. The corona region of the Sun is normally only visible during a solar eclipse.


title: Star

text: From the corona, a stellar wind of plasma particles expands outward from the star, until it interacts with the interstellar medium. For the Sun, the influence of its solar wind extends throughout a bubble-shaped region called the heliosphere.


title: Star

text: When nuclei fuse, the mass of the fused product is less than the mass of the original parts. This lost mass is converted to electromagnetic energy, according to the mass–energy equivalence relationship formula_3. A variety of nuclear fusion reactions take place in the cores of stars, that depend upon their mass and composition.


title: Star

text: The hydrogen fusion process is temperature-sensitive, so a moderate increase in the core temperature will result in a significant increase in the fusion rate. As a result, the core temperature of main sequence stars only varies from 4 million kelvin for a small M-class star to 40 million kelvin for a massive O-class star.


title: Star

text: In the Sun, with a 16-million-kelvin core, hydrogen fuses to form helium in the proton–proton chain reaction:


title: Star

text: There are a couple other paths, in which He and He combine to form Be, which eventually (with the addition of another proton) yields two He, a gain of one.


title: Star

text: where γ is a gamma ray photon, ν is a neutrino, and H and He are isotopes of hydrogen and helium, respectively. The energy released by this reaction is in millions of electron volts. Each individual reaction produces only a tiny amount of energy, but because enormous numbers of these reactions occur constantly, they produce all the energy necessary to sustain the star's radiation output. In comparison, the combustion of two hydrogen gas molecules with one oxygen gas molecule releases only 5.7 eV.


title: Star

text: In more massive stars, helium is produced in a cycle of reactions catalyzed by carbon called the carbon-nitrogen-oxygen cycle.


title: Star

text: In evolved stars with cores at 100 million kelvin and masses between 0.5 and 10 , helium can be transformed into carbon in the triple-alpha process that uses the intermediate element beryllium:


title: Star

text: In massive stars, heavier elements can be burned in a contracting core through the neon-burning process and oxygen-burning process. The final stage in the stellar nucleosynthesis process is the silicon-burning process that results in the production of the stable isotope iron-56. Any further fusion would be an endothermic process that consumes energy, and so further energy can only be produced through gravitational collapse.


title: Tropic Thunder

text: Tropic Thunder is a 2008 satirical action comedy film directed by Ben Stiller, who wrote the screenplay with Justin Theroux and Etan Cohen. The film stars Stiller, Jack Black, Robert Downey Jr., Jay Baruchel, and Brandon T. Jackson as a group of prima donna actors making a Vietnam War film. When their frustrated director (Steve Coogan) drops them in the middle of a jungle, they are forced to rely on their acting skills to survive the real action and danger. "Tropic Thunder" parodies many famous war films, specifically those based on the Vietnam War. The ensemble cast includes Tom Cruise, Nick Nolte, Danny McBride, Matthew McConaughey, and Bill Hader.


title: Tropic Thunder

text: Stiller developed "Tropic Thunder" premise during the production of "Empire of the Sun" in the spring of 1987, and later enlisted Theroux and Cohen to complete a script. The film was green-lit in 2006 and produced by Stuart Cornfeld, Stiller, and Eric McLeod for Red Hour Productions and DreamWorks Pictures as an international coproduction between the United States, Germany, and the United Kingdom. Filming took place in 2007 on the Hawaiian island of Kaua'i over thirteen weeks and was the largest film production in the island's history. The extensive marketing campaign included faux websites for three of the main characters and their fictional films, a fictional television special, and selling the energy drink advertised in the film, "Booty Sweat".


title: Tropic Thunder

text: Paramount Pictures and DreamWorks released "Tropic Thunder" in the United States on August 13, 2008. It received generally positive reviews for its characters, story, faux trailers, and cast performances. However, the depiction of the mentally handicapped and use of blackface makeup attracted controversy. The film opened at the top of the American box office and retained the number-one position for three consecutive weeks, ultimately grossing more than $195 million worldwide before its release on home media on November 18, 2008. Downey was nominated for an Academy Award, a BAFTA Award, and a Screen Actors Guild Award, while both he and Cruise received nominations for a Golden Globe Award.


title: Tropic Thunder

text: Hook-handed Vietnam veteran Staff Sergeant John "Four Leaf" Tayback's memoir "Tropic Thunder" is being made into a film. With the exception of newcomer supporting actor Kevin Sandusky, the cast—fading action hero Tugg Speedman, overbearing five-time Academy Award-winning Australian method actor Kirk Lazarus, loudmouthed rapper Alpa Chino, and drug-addicted comedian Jeff Portnoy—all cause problems for the inexperienced director Damien Cockburn, who cannot control them, resulting in a million-dollar pyrotechnics scene being wasted. With the project months behind schedule, studio executive Les Grossman gives Damien an ultimatum: get the cast under control or the project will be cancelled.


title: Tropic Thunder

text: On Four Leaf's advice, Damien drops the actors into the middle of the jungle, with hidden cameras and rigged special effects explosions to film "guerrilla-style". The actors have guns that fire blanks, along with a map and scene listing that will lead to a helicopter waiting at the end of the route. Unknown to the actors and production, the group has been dropped in the middle of the Golden Triangle, the home of the heroin-producing Flaming Dragon gang. Just as the group is about to set off, Damien inadvertently steps on an old land mine and is blown up, stunning the actors. Tugg, believing Damien faked his death to encourage the cast to give better performances, assures the others that Damien is alive, and that they are still shooting the film. Kirk is unconvinced but joins them in their trek to get out of the jungle.


title: Tropic Thunder

text: When Four Leaf and pyrotechnics operator Cody Underwood try to locate the deceased director, they are captured by Flaming Dragon. Four Leaf is revealed to have hands; he confesses to Underwood that he actually served in the Coast Guard, has never left the United States, and that he wrote his "memoir" as a tribute. As the actors continue through the jungle, Kirk, who has become convinced that Tugg's ineptitude is putting them in jeopardy, and Kevin, the only actor who bothered to properly prepare for his role, discover that Tugg is leading them in the wrong direction. The resulting argument results in Kirk leading the rest of the cast back toward the resort they are staying at as an increasingly delirious Tugg is captured by Flaming Dragon. Taken to their base, Tugg believes it is a POW camp from the script. The gang discovers he is the star of their favorite film, the box-office bomb "Simple Jack", and forces him to reenact it several times a day, leading him to become brainwashed.


title: Tropic Thunder

text: Meanwhile, in Los Angeles, Tugg's agent, Rick "Pecker" Peck, confronts Les over an unfulfilled term in Tugg's contract that entitles him to a TiVo. Flaming Dragon calls during the discussion and demands a ransom for Tugg, but Les instead delivers a profanity-laden death threat. Les is uninterested in rescuing Tugg and is instead delighted at the prospect of a large insurance payout if Tugg dies. He attempts to convince Pecker to play along by promising a Gulfstream V jet and "lots of money".


title: Tropic Thunder

text: Kirk, Alpa, Jeff, and Kevin discover Flaming Dragon's heroin factory. After witnessing Tugg being tortured, they plan a rescue attempt based on the film's script. Kirk impersonates a farmer towing a "captured" Jeff on the back of a water buffalo, distracting the armed guards so Alpa and Kevin can infiltrate and find the prisoners, but a combination of broken Mandarin Chinese and inconsistencies in his story sets off the gang's boss. The actors, knowing their cover has been blown, begin firing, fooling the gang members into surrender. Their control of the gang falls apart when Jeff grabs the leader and heads for the drugs, and the gang, realizing the guns fire blanks, recover their guns and fight back.


title: Tropic Thunder

text: The four actors locate Four Leaf, Underwood, and Tugg and cross a bridge rigged to explode to get to Underwood's helicopter. Tugg initially remains behind, believing Flaming Dragon to be his "family", but runs back screaming, chased by an angry horde. Four Leaf destroys the bridge, rescuing Tugg, but as the helicopter takes off, the gang boss fires an RPG at the helicopter. Rick unexpectedly stumbles out of the jungle and saves them by throwing a TiVo box into the path of the rocket. The crew return to Hollywood and footage from the hidden cameras is compiled into the feature film "Tropic Blunder", which becomes a major critical and commercial success. The film wins Tugg his first Academy Award, which Kirk presents to him at the ceremony.


title: Tropic Thunder

text: Various actors and celebrities portray themselves, including Tobey Maguire, Tyra Banks, Maria Menounos, Martin Lawrence, The Mooney Suzuki, Jason Bateman, Lance Bass, Jennifer Love Hewitt, Alicia Silverstone, Christine Taylor, Mini Anden, Anthony Ruivivar, Yvette Nicole Brown, Rachel Avery, Sean Penn, and Jon Voight. Co-writer Justin Theroux appears in two brief roles as a UH-1 Huey gunner and the disc jockey from "Zoolander" (shown in a deleted scene).


title: Tropic Thunder

text: Stiller developed the premise for "Tropic Thunder" while shooting "Empire of the Sun", in which he played a small part. Stiller wanted to make a film based on the actors he knew who, after taking part in boot camps to prepare for war film roles, became "self-important" and "self-involved" and appeared to believe they had been part of a real military unit.


title: Tropic Thunder

text: Co-writer Theroux revealed that the initial script concept was to have actors go to a mock boot camp and return with posttraumatic stress disorder. The final script was developed to satirize Vietnam War films such as "Apocalypse Now", "Rambo", "Missing in Action", "Platoon", "Full Metal Jacket", "Hamburger Hill", and "The Deer Hunter". Theroux pointed out that since viewers had an increased awareness of the inner workings of Hollywood due to celebrity websites and Hollywood news sources, the script was easier to write. Dialogue for unscripted portions of the storyboard was developed on set by the actors or was improvised.


title: Tropic Thunder

text: Stiller's original plan was to cast Keanu Reeves as Tugg Speedman and himself as Rick Peck. Etan Cohen created the role of Kirk Lazarus as a way of lampooning the great lengths that some method actors go to depict a role. Downey was approached by Stiller about the part while on vacation in Hawaii. Downey said on CBS' "The Early Show" that his first reaction was, "This is the stupidest idea I've ever heard!" and that Stiller responded, "Yeah, I know – isn't it great?" In another interview, Downey said that he accepted the part but, having no idea where or even how to start building the character of Lazarus, eventually settled on a jive-esque speech pattern and a ragged bass voice; he then auditioned Lazarus' voice over the phone to Stiller, who approved the characterization immediately. Downey revealed that he modeled the character on actors Russell Crowe, Colin Farrell, and Daniel Day-Lewis. The initial script was written for Downey's character to be Irish, but was altered after Downey stated he could improvise better as an Australian (he had previously played a similar outlandish Australian character in the film "Natural Born Killers"). Downey's practice of remaining in character between takes and even off the film set was also written into the script for his character to perform. Downey required between one and a half to two hours of make-up application. According to Downey, "One makeup artist would start on one side of my face and a second makeup artist would start on the other side, and then they'd meet in the middle."


title: Tropic Thunder

text: Downey acknowledged the potential controversy over his role: "At the end of the day, it's always about how well you commit to the character. If I didn't feel it was morally sound, or that it would be easily misinterpreted that I'm just C. Thomas Howell [in "Soul Man"], I would've stayed home." Co-star Brandon T. Jackson stated: "When I first read the script, I was like: What? Blackface? But when I saw him [act] he, like, became a black man ... It was just good acting. It was weird on the set because he would keep going with the character. He's a method actor." Stiller commented on Downey's portrayal of a white actor playing a black man: "When people see the movie – in the context of the film, he's playing a method actor who's gone to great lengths to play a black guy. The movie is skewering actors and how they take themselves so seriously." Stiller previewed the film before the NAACP, and several black journalists reacted positively to the character.


title: Tropic Thunder

text: Cruise was initially set to cameo as Stiller's character's agent, Rick Peck. Instead, Cruise suggested adding a studio head character, and the idea was incorporated into the script. Stiller and Cruise worked together to create the new character, Les Grossman, as a middle-aged businessman. The role required that Cruise don a fatsuit, large prosthetic hands, and a bald cap. It was Cruise's idea to give the character large hands and dance to "Low". Stiller intended to keep Cruise's role a secret until the film's release. In addition, Paramount Pictures refused to release promotional pictures of Cruise's character to the media. In November 2007, images of Cruise wearing a bald headpiece and a fatsuit appeared on "Inside Edition", as well as on the Internet. Cruise's attorneys threatened a lawsuit if photos showing Cruise in costume were published. They approached various sites that were hosting the image and quickly had it removed. A representative for Cruise stated: "Mr. Cruise's appearance was supposed to be a surprise for his fans worldwide. Paparazzi have ruined what should have been a fun discovery for moviegoers." The photography agency INF, who debuted the image, responded with a statement: "While these pictures were taken without breaking any criminal or civil laws, we've decided to pull them from circulation effective immediately."


title: Tropic Thunder

text: Serving as a last-minute replacement, Tobey Maguire was available to be on set for only two hours to film his scenes in "Satan's Alley". Downey said he was amazed Maguire would agree to do the film and felt like they were creating a "karmic pay-off" for their scenes together in the 2000 film "Wonder Boys", where Downey's character has a one-night stand with Maguire's character. After Cruise vacated the role of Rick Peck, Owen Wilson was cast to play the part. Following his suicide attempt in August 2007, Wilson dropped out of the film and was replaced by Matthew McConaughey.


title: Tropic Thunder

text: Although Southern California and Mexico were considered for the main unit filming, the Hawaiian island of Kaua'i (where Stiller has a home) was selected for the majority of the shooting. Kaua'i was chosen over Mexico because a tax credit for in-state spending was negotiated with the Kaua'i Film Commission. John Toll, the cinematographer, stated the island was also selected for its similarity to Vietnam, based on its dense foliage, variety of terrains, and weather. Kaua'i was first scouted as a possible location to film "Tropic Thunder" in 2004. Stiller spent more than 25 hours over 6 weeks exploring the island, using all-terrain vehicles, boats, and helicopters. After the film was greenlit by DreamWorks in 2006, preproduction lasted for six months, most of this time spent on scouting additional locations for filming. Filming for the Los Angeles and interior scenes occurred on sets at Universal Studios in Hollywood.


title: Tropic Thunder

text: "Tropic Thunder" was the first major studio production on Kaua'i in five years. After filming was completed, it was deemed the largest production filmed on the island to date, and contributed more than $60 million to the local economy. Tim Ryan, the executive editor of "Hawaii Film & Video Magazine", commented on the filming on the island: "I think "Tropic Thunder" will give Kaua'i much needed and long idled publicity in the production arena ... It should put Kaua'i back on the production consideration radar." Preliminary production crews were on the island starting in December 2006 and principal photography began in July 2007, with filming lasting thirteen weeks over seven separate locations on the island. Much of the filming took place on private land as well as conservation status designated areas. Casting calls on the island sought 500 residents to portray the villagers in the film. Two units shot simultaneously on the island from the ground, and an aerial unit shot from helicopters. Many of the sets and the bridge used for one of the final scenes were built in three months. The island's erratic weather hampered filming with rain and lighting issues. The crew also faced complications in moving the equipment and cast due to the difficult terrain.


title: Tropic Thunder

text: The film advising company Warriors Inc. was enlisted to ensure the war scenes, including the attire worn by the actors, looked authentic. Former members of the U.S. military taught the actors how to handle, fire, and reload their weapons, as well as perform various tactical movements. The opening war scene was filmed over three weeks and required fifty stuntmen. Animatics were used to map out the necessary camera angles for filming.


title: Tropic Thunder

text: Six companies working on different scenes and elements created 500 shots of visual effects in the film. These were at times altered weekly due to the reactions of test audiences in screenings. CIS Visual Effects Group assisted with the "Scorcher VI" faux trailer and twenty additional shots for the home media release. To expand on the comedy in the film, some of the explosions and crashes were embellished to look more destructive. The visual effects supervisor Michael Fink reflected on the exaggerated explosions: "We worked really hard to make the CG crashing helicopter in the hot landing sequence look real. Ben was adamant about that, but at the same time he wanted the explosion to be huge. When you see it hit the ground, it was like it was filled with gasoline! It was the same thing with Ben's sergeant character, who almost intercepts a hand grenade ... Now, I was in the Army for three years and no hand grenade would make an explosion like that ... But it was a big dramatic moment and it looks really cool ... and feels kind of real."


title: Tropic Thunder

text: Filming the large napalm explosion in the opening scene of the film required a 450-foot (137-meter) row of explosive pots containing 1,100 gallons (4,165 liters) of gasoline and diesel fuel. All the palm trees used in the explosion were moved to the specific location after the crew determined the impact of the lighting and necessary camera angles. Due to the size and cost of the 1.25-second explosion, it was performed only once and was captured by twelve cameras. For the safety of the crew and cast, the detonators were added one hour before the explosion and nobody was allowed to be within during detonation. The explosion was made up of twelve individual explosions and resulted in a mushroom cloud that reached in the air. For the scene in the film, Danny McBride's character, Cody Underwood, was the only actor shown in the shot of the explosion. All the other characters were added digitally. The explosion of the bridge in one of the final scenes used nine cameras to capture the shot, and the crew was required to be away for their safety.


title: Tropic Thunder

text: A trailer for the film was released in April 2008. The "Calgary Herald" gave it a rating of 3/5, commenting: "This could either be good or very, very bad." Gary Susman of "Entertainment Weekly" questioned whether the film would "... turn into precisely the kind of bloated action monstrosity that it's making fun of." The trailer received the "Best Comedy Trailer" award at the 9th annual Golden Trailer Awards. DreamWorks also released a red band trailer, the first of its kind used by the studio to promote one of its films.


title: Tropic Thunder

text: Stiller, Downey, and Black appeared on the seventh-season finale of "American Idol" in a sketch as The Pips performing with Gladys Knight (via archival footage). The three actors also later performed a sketch at the 2008 MTV Movie Awards which featured the actors attempting to create a successful viral video to promote the film with awkward results. In September 2008, Stiller and Downey attended the San Sebastián International Film Festival to promote the film. A screening was shown, but it was not chosen to compete against the other films at the festival.


title: Tropic Thunder

text: Between April 2008 and the film's commercial release in August 2008, the film had over 250 promotional screenings. On August 3, 2008, Stiller, Downey, and Black visited Camp Pendleton, a U.S. Marine Corps base in California, to present a screening to over a thousand military members and their families. The screening was on behalf of the United Service Organizations and included the actors heading to the screening by helicopter and Humvees. On August 8, 2008, a special 30-minute fictional "E! True Hollywood Story" aired about the making of "Tropic Thunder". In video games, a themed scavenger hunt was incorporated into "", and Stiller allowed his likeness to be used in the online Facebook application game based on the film.


title: Tropic Thunder

text: As a tie-in for the film's release, Paramount announced it would market the energy drink known in the film as "Booty Sweat". Michael Corcoran, Paramount's president of consumer products, commented on the release: "We're very excited, because it has the potential to live for quite a while, well beyond the film." The drink was sold in college bookstores, on Amazon.com, and at other retailers.


title: Tropic Thunder

text: Several faux websites were created for the characters and some of their prior film roles. A website for "Simple Jack", a faux film exhibited within the film, was removed by DreamWorks on August 4, 2008, due to protests from disability advocates. In addition, other promotional websites were created for "Make Pretty Skin Clinic", the fictitious company that performed the surgery of the film's character Kirk Lazarus, along with one for the energy drink "Booty Sweat".


title: Tropic Thunder

text: In mid-July 2008, a faux trailer for the mockumentary "Rain of Madness" was released. The mockumentary was a parody of "". It follows co-writer Justin Theroux as a fictitious documentarian named Jan Jürgen documenting the behind-the-scenes aspects of the film within the film. Marketing for the faux documentary included a movie poster and an official website prior to "Tropic Thunder"s release. The mockumentary was released on the iTunes Store after the film's release and was also included on the home video release. Amy Powell, an advertising executive with Paramount, reflected on the timing of the release of "Madness": "We always thought that people would be talking about "Tropic Thunder" at the water cooler, and that's why we decided to release "Rain of Madness" two weeks into "Tropic"s run—to keep this positive buzz going."


title: Tropic Thunder

text: "Tropic Thunder" held an early screening at the 2008 San Diego Comic-Con, two weeks before it officially premiered on August 11, 2008, at the Mann Village Theatre in Westwood, California and two days before its wide release. Members of several disability groups picketed before the premiere, protesting at the portrayal of intellectual disability shown in the film. The groups revealed that it was the first time that they had ever protested together at an event. As a result of the protest, the normally unobstructed views of the red carpet leading to the premiere were blocked off by 10-foot (3-m)-high fences and there was an increase in the number of security personnel present. No protests were held at the United Kingdom's September premiere.


title: Tropic Thunder

text: The North American release was scheduled for July 11, 2008, but was delayed until August 15, before being brought forward to August 13. As a result of the move from July, 20th Century Fox moved its family comedy "Meet Dave" in the open slot. The August 13 release date was also the opening weekends for the animated family film "" and the horror film "Mirrors". Studios consider the third week of August to be a weaker performing period than earlier in the summer because of students returning to school. Previous R-rated comedies such as "The 40-Year-Old Virgin" and "Superbad" were released in mid-August and performed well at the box office. Reacting to "Tropic Thunder"'s release date, Rob Moore, vice chairman of Paramount Pictures, stated, "For a young person at the end of summer, you want to have some fun and forget about going back to school. What better than a crazy comedy?"


title: Tropic Thunder

text: "Tropic Thunder" was released in the United States on DVD and Blu-ray on November 18, 2008, three months after its release and a week after the end of its theatrical run in the U.S. and Canada. The film was released on home video on January 26, 2009, in the United Kingdom. Special features include an unrated director's cut of the film which is 12 minutes longer than the theatrical release, audio commentaries (including one featuring Stiller, Downey, and Black, with Downey providing his commentary as Lincoln Osiris, a nod to a joke in the film that Lazarus never breaks character until he completes the DVD commentary), several featurettes, deleted scenes, an alternate ending, and the "Rain of Madness" mockumentary.


title: Tropic Thunder

text: For the film's first week of release, "Tropic Thunder" placed on several video charts. It reached second place on the Nielsen VideoScan First Alert sales chart and Nielsen's Blu-ray Disc chart, earning $19,064,959 (not including Blu-ray sales). In rentals, it placed first on the "Home Media Magazine"'s video rental chart. The DVD sales in 2008 totaled $42,271,059, placing it in 28th for DVD sales for the year. By September 2009, 2,963,000 DVD units have been sold, gathering revenue of $49,870,248.


title: Tropic Thunder

text: The upcoming HDR Dolby Vision mastered Ultra HD Blu-ray is scheduled to be released through Kino Lorber.


title: Tropic Thunder

text: The review aggregation website Rotten Tomatoes gives the film a rating of 82% based on 252 reviews and an average rating of 7.1/10. The website's critical consensus reads, "With biting satire, plenty of subversive humor, and an unforgettable turn by Robert Downey Jr., "Tropic Thunder" is a triumphant late summer comedy." Metacritic, which assigns a weighted average score from reviews by mainstream critics, gave a film score of 71 out of 100 based on 39 critics, indicating "generally favorable reviews".


title: Tropic Thunder

text: After attending an industry screening in April 2008, Michael Cieply from the "New York Times" stated that the film was "shaping up as one of [DreamWorks]'s best prospects for the summer." Claudia Puig of "USA Today" gave the film a positive review, writing "There are some wildly funny scenes, a few leaden ones and others that are scattershot, with humorous satire undercut by over-the-top grisliness. Still, when it's funny, it's really funny." A review in "Variety" by Todd McCarthy was critical: "Apart from startling, out-there comic turns by Robert Downey Jr. and Tom Cruise, however, the antics here are pretty thin, redundant and one-note." Glenn Kenny of "RogerEbert.com" would later call the film "intermittently amusing but entirely smug and hateful." Rick Groen of "The Globe and Mail" also gave the film a negative review, calling it "... an assault in the guise of a comedy—watching it is like getting mugged by a clown." J.R. Jones of "Chicago Reader" stated "The rest of the movie never lives up to the hilarity of the opening, partly because the large-scale production smothers the gags but mostly because those gags are so easy to smother." Roger Ebert of the "Chicago Sun-Times" gave 3.5/4 and wrote, "The movie is, may I say, considerably better than Stiller’s previous film, "Zoolander" (2001). It’s the kind of summer comedy that rolls in, makes a lot of people laugh and rolls on to video."


title: Tropic Thunder

text: The faux trailers before the film also received mixed reviews. David Ansen of "Newsweek" approved of the trailers, writing ""Tropic Thunder" is the funniest movie of the summer—so funny, in fact, that you start laughing before the film itself has begun." Christy Lemire, writing for the Associated Press, called the trailers "... the best part of the trip." Robert Wilonsky of "The Village Voice" was critical, saying that the trailers' comedy "... resides in the land of the obvious, easy chuckle."


title: Tropic Thunder

text: Downey, Stiller, Black and Cruise were repeatedly singled out for praise by numerous critics, claiming that they "stole the show", were "... off-the-charts hilarious ...", and would bring viewers "... the fondest memories of [their] work." Scott Feinberg, of the "Los Angeles Times", criticized the concept of Downey's portrayal of an African-American, writing "... I just can't imagine any circumstance under which a blackface performance would be acceptable, any more than I can imagine any circumstance under which the use of the N-word would be acceptable." Sara Vilkomerson said Cruise did "... an astonishingly funny and surprising supporting performance." Logan Hill of "New York" argued against Cruise's cameo saying that it "... just makes him look a little lost and almost pathetic—shucking and jiving, trying to appeal to the younger moviegoers who are abandoning him."


title: Tropic Thunder

text: Several critics commented on the controversy over lines in the film talking about the mentally disabled. Duane Dudek of the "Milwaukee Journal Sentinel" wrote that the film "... is just sophomoric enough to offend. And while it is also funny, it is without the empathy or compassion to cause us to wonder why we are laughing." Christian Toto of "The Washington Times" argued against the opposition, ""Tropic Thunder" is drawing fire from special interest groups for ... its frequent use of the word 'retard', but discerning audiences will know where the humor is targeted. And they'll be laughing too hard to take offense." Kurt Loder of MTV contrasted the opposition to the lines with Downey's character portraying an African American, "The scene in which the derisive Alpa Chino (Brandon T. Jackson) nails Lazarus' recitation of black-uplift homilies as nothing more than the lyrics to the "Jeffersons" theme is funny; but the one in which Lazarus quietly explains to Speedman that his "Simple Jack" character failed because he made the mistake of going 'full retard'—rather than softening his character with cuteness in the manner of "Forrest Gump"—is so on-the-nose accurate, it takes your breath away."


title: Tropic Thunder

text: In January 2009, "Entertainment Weekly" included "Tropic Thunder" in its list "25 Great Comedies From the Past 25 Years" for its "spot-on skewering of Hollywood." The film also appeared on several critics' top ten lists of the best films of 2008. Stephen King placed it at the fourth position, calling the film "the funniest, most daring comedy of the year." "The Oregonian"s Marc Mohan, placed it sixth, and several critics placed it seventh: Elizabeth Weitzman of the "New York Daily News", "Premiere" magazine, Mike Russell of "The Oregonian", as well as Peter Hartlaub of the "San Francisco Chronicle". David Ansen of "Newsweek" placed it eighth and Lisa Schwarzbaum of "Entertainment Weekly" included the film in the tenth position.


title: Tropic Thunder

text: Stacey Snider, the chief executive of DreamWorks, suggested that the film would earn around $30 million in its opening weekend and go on to be as successful as "Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan", which earned $129 million in the U.S. and Canada and $260 million worldwide. "The Dark Knight" had been the number one film at the box office for the four weeks prior to the release of "Tropic Thunder". Bob Thompson, a writer for the "National Post", speculated that "Tropic Thunder"s opening weekend would outperform "The Dark Knight" for the weekend. In a list compiled prior to the summer's film releases, "Entertainment Weekly" predicted that the film would be the tenth highest-grossing film of the summer at the American box office with $142.6 million.


title: Tropic Thunder

text: "Tropic Thunder" opened in 3,319 theaters and, for its first five days of American and Canadian release, earned $36,845,588. The film placed first in the weekend's box office with $25,812,796, surpassing "" and "Mirrors", which debuted the same weekend. Reacting to the film's opening receipts, DreamWorks spokesman Chip Sullivan stated, "We're thrilled, quite frankly. It played out exactly how we hoped." In foreign markets for the film's opening weekend, it was released in 418 Russian and 19 United Arab Emirates locations earning $2.2 million and $319,000, respectively.


title: Tropic Thunder

text: The film maintained its number one position at the American and Canadian box office for the following two weekends, making it the second film in 2008 (after "The Dark Knight") to hold the number-one position for more than two consecutive weekends. The film's widest release was in 3,473 theaters, placing it in the top 25 widest releases in the U.S. for 2008. For 2008, the film was the fifth-highest-grossing domestic R-rated film. The film's U.S. and Canada gross of over $110 million made "Tropic Thunder" Stiller's most successful film as a director. The film has had gross receipts of $110,515,313 in the U.S. and Canada and $85,187,498 in international markets for a total of $195,702,811 worldwide.


title: Tropic Thunder

text: In October 2008, Paramount chose to put end-of-year award push funds behind "Tropic Thunder" and began advertising for Downey to receive a nomination by the Academy Awards for Best Supporting Actor. In a November 2008 issue by "Entertainment Weekly", Downey's film role was considered one of the three contenders for Best Supporting Actor. As a way of extending the film-within-a-film "universe" into real life, there were at least two online "For Your Consideration" ads touting Downey's character, Kirk Lazarus, for Best Supporting Actor; one of these contains "scenes" from "Satan's Alley" that were not in the trailer as released in theaters. At least one of the ads was produced by Paramount Pictures and intended for early For Your Consideration awareness for Downey's role. On January 22, 2009, the Academy of Motion Picture Arts and Sciences nominated Downey for Best Supporting Actor. At the 81st Academy Awards, Downey lost to Heath Ledger for his role as The Joker in "The Dark Knight".


title: Tropic Thunder

text: With the onset of the annual Hollywood film award season at the end of 2008, "Tropic Thunder" began receiving nominations and awards starting with a win for "Hollywood Comedy of the Year Award" at the 12th annual Hollywood Film Festival on October 27, 2008. The film was nominated for Best Motion Picture, Comedy or Musical, for the Satellite Awards. In addition, Downey was nominated for Best Actor in a Supporting Role. The Broadcast Film Critics Association nominated Downey for Best Supporting Actor and awarded "Tropic Thunder" Best Comedy Movie at the BFCA's Critics' Choice Awards. Both Downey and Cruise received nominations from the Hollywood Foreign Press Association for Golden Globes for Best Supporting Actor. The Boston Society of Film Critics recognized the cast with its Best Ensemble award. Downey was also nominated by both the Screen Actors Guild and the British Academy of Film and Television Arts for Best Supporting Actor awards.


title: Tropic Thunder

text: "Tropic Thunder" was criticized by the disability advocacy community. The website for "Simple Jack" was withdrawn on August 4 amid several groups' concerns over its portrayal of intellectual disability. A spokesman for DreamWorks said, "We heard their concerns, and we understand that taken out of context, the site appeared to be insensitive to people with disabilities." A coalition of more than 20 disability advocacy groups, including the Special Olympics and the Arc of the United States, objected to the film's repeated use of the word "retard". DreamWorks offered to screen the film for the groups on August 8 to determine if it still offended them. The screening was postponed to the same day of the premiere on August 11. After representatives for the groups attended the private screening and were still offended by its content, the groups picketed outside the film's premiere. Timothy Shriver, the chairman of the Special Olympics, stated, "This population struggles too much with the basics to have to struggle against Hollywood. We're sending a message that this hate speech is no longer acceptable."


title: Tropic Thunder

text: Disability advocates and others who previewed the film reported that the offensive treatment of individuals with mental disabilities was woven throughout the film's plot. Disability advocates urged people not to see the film, claiming it is demeaning to individuals with mental disabilities and would encourage bullying. Stiller defended the film, stating "We screened the movie so many times and this didn't come up until very late ... in the context of the film I think it's really clear, they were making fun of the actors and actors who try to use serious subjects to win awards." Co-writer Etan Cohen echoed Stiller's rationale: "Some people have taken this as making fun of handicapped people, but we're really trying to make fun of the actors who use this material as fodder for acclaim." He went on to state that the film lampoons actors who portray intellectually disabled or autistic characters such as Dustin Hoffman in "Rain Man", Tom Hanks in "Forrest Gump", and Sean Penn in "I Am Sam".


title: Tropic Thunder

text: A DreamWorks spokesman did not directly respond to the criticism, claiming that "Tropic Thunder" "is an R-rated comedy that satirizes Hollywood and its excesses" and "makes its point by featuring inappropriate and over-the-top characters in ridiculous situations." The film's advertising was altered, but none of the scenes in the film were edited as a result of the opposition. In response to the controversy, the director's cut of the DVD (but not the Blu-ray) includes a public service announcement in the special features that discourages use of the word "retard".


title: Tropic Thunder

text: Another aspect that drew warning before the release of the movie and criticism afterwards was Robert Downey Jr. playing a white Australian actor who dons brownface/blackface as part of his method acting the role of an African-American man. He responded by pointing out that this was a case of donning blackface in order to point out how wrong it is. Others have pointed out that the wrongness of blackface is addressed within the movie itself by an actual African-American, and that the climax of movie pins on Downey Jr.'s shedding of his method acting; in this way, the movie mocks—rather than embraces—both blackface and the extreme and ridiculous things method actors sometimes do for their roles.


title: Tropic Thunder

text: Some have alleged that the film's characterization—and the non-Jewish Tom Cruise's portrayal—of the Jewish character Les Grossman is anti-Semitic. In addition to his Jewish name, the character of Grossman also references the Jewish holiday of Purim. Critics have also referred to this performance as "Jewface" as early as 2008 (years before Sarah Silverman raised awareness of the term), calling it "vulgar" and "exploitation"; others, however, including the "St. Louis Jewish Light", which referenced "Tropic Thunder" in particular, noted that Jewface was a "riff on the practice of blackface and is nowhere near its equivalent." It is worth noting that Stiller, the movie's director, is himself Jewish. Reportedly, Tom Cruise was largely responsible for the final form Les Grossman took, including using him as an additional villain, the hairiness of the character, and the "fat hands".


title: Tropic Thunder

text: "Tropic Thunder"s score and soundtrack were released on August 5, 2008, the week before the film's theatrical release. The score was composed by Theodore Shapiro and performed by the Hollywood Studio Symphony. William Ruhlmann of AllMusic gave the score a positive review, stating it is "...an affectionate and knowing satire of the history of Hollywood action movie music, penned by an insider." Thomas Simpson of Soundtrack.Net called it "...a mixture of fun, seriousness, rock n' roll and great scoring."


title: Tropic Thunder

text: Five songs—"Cum On Feel the Noize" by Quiet Riot, "Sympathy for the Devil" by The Rolling Stones, "For What It's Worth" by Buffalo Springfield, "Low" by Flo Rida and T-Pain, and "Get Back" by Ludacris—were not present on the soundtrack despite appearing in the film. The soundtrack features songs from The Temptations, MC Hammer, Creedence Clearwater Revival, Edwin Starr, and other artists. The single "Name of the Game" by The Crystal Method, featuring Ryu, has an exclusive remix on the soundtrack. The soundtrack debuted 20th on "Billboard"'s Top Soundtracks list and peaked at 39th on its Top Independent Albums list. James Christopher Monger of allmusic compared the music to other film's soundtracks such as "Platoon", "Full Metal Jacket", and "Forrest Gump" and called it "...a fun but slight listen that plays out like an old late-'70s K-Tel compilation with a few bonus cuts from the future."


title: Tropic Thunder

text: Cruise reprised his character Les Grossman for the 2010 MTV Movie Awards. A spin-off film centering on Grossman was announced in 2010. A script has been written by Michael Bacall. In 2012, Bacall said the film will explore the origin of Grossman's anger issues. As of 2022, Cruise and frequent collaborator Christopher McQuarrie are developing the spin-off, though it is not clear whether Grossman will be the protagonist or a supporting character.


title: Guitar

text: The guitar is a fretted musical instrument that typically has six strings. It is usually held flat against the player's body and played by strumming or plucking the strings with the dominant hand, while simultaneously pressing selected strings against frets with the fingers of the opposite hand. A plectrum or individual finger picks may also be used to strike the strings. The sound of the guitar is projected either acoustically, by means of a resonant chamber on the instrument, or amplified by an electronic pickup and an amplifier.


title: Guitar

text: The guitar is classified as a chordophone – meaning the sound is produced by a vibrating string stretched between two fixed points. Historically, a guitar was constructed from wood with its strings made of catgut. Steel guitar strings were introduced near the end of the nineteenth century in the United States; nylon strings came in the 1940s. The guitar's ancestors include the gittern, the vihuela, the four-course Renaissance guitar, and the five-course baroque guitar, all of which contributed to the development of the modern six-string instrument.


title: Guitar

text: There are three main types of modern guitar: the classical guitar (Spanish guitar/nylon-string guitar); the steel-string acoustic guitar or electric guitar; and the Hawaiian guitar (played across the player's lap). Traditional acoustic guitars include the flat top guitar (typically with a large sound hole) or an archtop guitar, which is sometimes called a "jazz guitar". The tone of an acoustic guitar is produced by the strings' vibration, amplified by the hollow body of the guitar, which acts as a resonating chamber. The classical Spanish guitar is often played as a solo instrument using a comprehensive fingerstyle technique where each string is plucked individually by the player's fingers, as opposed to being strummed. The term "finger-picking" can also refer to a specific tradition of folk, blues, bluegrass, and country guitar playing in the United States.


title: Guitar

text: Electric guitars, first patented in 1937, use a pickup and amplifier that made the instrument loud enough to be heard, but also enabled manufacturing guitars with a solid block of wood needing no resonant chamber. A wide array of electronic effects units became possible including reverb and distortion (or "overdrive"). Solid-body guitars began to dominate the guitar market during the 1960s and 1970s; they are less prone to unwanted acoustic feedback. As with acoustic guitars, there are a number of types of electric guitars, including hollowbody guitars, archtop guitars (used in jazz guitar, blues and rockabilly) and solid-body guitars, which are widely used in rock music.


title: Guitar

text: The loud, amplified sound and sonic power of the electric guitar played through a guitar amp has played a key role in the development of blues and rock music, both as an accompaniment instrument (playing riffs and chords) and performing guitar solos, and in many rock subgenres, notably heavy metal music and punk rock. The electric guitar has had a major influence on popular culture. The guitar is used in a wide variety of musical genres worldwide. It is recognized as a primary instrument in genres such as blues, bluegrass, country, flamenco, folk, jazz, jota, ska, mariachi, metal, punk, funk, reggae, rock, grunge, soul, acoustic music, disco, adult contemporary music, and pop.


title: Guitar

text: The modern word "guitar," and its antecedents, has been applied to a wide variety of chordophones since classical times and as such causes confusion. The English word "guitar," the German "," and the French ' were all adopted from the Spanish ', which comes from the Andalusian Arabic (') and the Latin ', which in turn came from the Ancient Greek This Greek word may also come from the Persian word Sihtar. Kithara appears in the Bible four times (1 Cor. 14:7, Rev. 5:8, 14:2 and 15:2), and is usually translated into English as "harp".


title: Guitar

text: The origins of the modern guitar are not known. Before the development of the electric guitar and the use of synthetic materials, a guitar was defined as being an instrument having "a long, fretted neck, flat wooden soundboard, ribs, and a flat back, most often with incurved sides." The term is used to refer to a number of chordophones that were developed and used across Europe, beginning in the 12th century and, later, in the Americas. A 3,300-year-old stone carving of a Hittite bard playing a stringed instrument is the oldest iconographic representation of a chordophone and clay plaques from Babylonia show people playing a lute like instrument which is similar to the guitar.


title: Guitar

text: A number of scholars cite many influences as antecedents to the modern guitar. Although the development of the earliest "guitars" is lost in the history of medieval Spain, two instruments are commonly cited as their most influential predecessors, the four-string oud and its precursor the European lute; the former was brought to Iberia by the Moors in the 8th century. It has often been assumed that the guitar is a development of the lute, or of the ancient Greek kithara. However, many scholars consider the lute an offshoot or separate line of development which did not influence the evolution of the guitar in any significant way.


title: Guitar

text: At least two instruments called "guitars" were in use in Spain by 1200: the ' (Latin guitar) and the so-called ' (Moorish guitar). The guitarra morisca had a rounded back, wide fingerboard, and several sound holes. The guitarra Latina had a single sound hole and a narrower neck. By the 14th century the qualifiers "moresca" or "morisca" and "latina" had been dropped, and these two chordophones were simply referred to as guitars.


title: Guitar

text: The Spanish vihuela, called in Italian the "", a guitar-like instrument of the 15th and 16th centuries, is widely considered to have been the single most important influence in the development of the baroque guitar. It had six courses (usually), lute-like tuning in fourths and a guitar-like body, although early representations reveal an instrument with a sharply cut waist. It was also larger than the contemporary four-course guitars. By the 16th century, the vihuela's construction had more in common with the modern guitar, with its curved one-piece ribs, than with the viols, and more like a larger version of the contemporary four-course guitars. The vihuela enjoyed only a relatively short period of popularity in Spain and Italy during an era dominated elsewhere in Europe by the lute; the last surviving published music for the instrument appeared in 1576.


title: Guitar

text: Meanwhile, the five-course baroque guitar, which was documented in Spain from the middle of the 16th century, enjoyed popularity, especially in Spain, Italy and France from the late 16th century to the mid-18th century. In Portugal, the word "viola" referred to the guitar, as "guitarra" meant the "Portuguese guitar", a variety of cittern.


title: Guitar

text: There were many different plucked instruments that were being invented and used in Europe, during the Middle Ages. By the 16th century, most of the forms of guitar had fallen off, to never be seen again. However, midway through the 16th century, the five-course guitar was established. It was not a straightforward process. There were two types of five-course guitars, they differed in the location of the major third and in the interval pattern. The fifth course can be placed on the instrument because it was known to play seventeen notes or more. Because the guitar had a fifth string, it was capable of playing that amount of notes. The guitar's strings were tuned in unison, so, in other words, it was tuned by placing a finger on the second fret of the thinnest string and tuning the guitar bottom to top. The strings were a whole octave apart from one another, which is the reason for the different method of tuning. Because it was so different, there was major controversy as to who created the five course guitar. A literary source, Lope de Vega's Dorotea, gives the credit to the poet and musician Vicente Espinel. This claim was also repeated by Nicolas Doizi de Velasco in 1640, however this claim has been refuted by others who state that Espinel's birth year (1550) make it impossible for him to be responsible for the tradition. He believed that the tuning was the reason the instrument became known as the Spanish guitar in Italy. Even later, in the same century, Gaspar Sanz wrote that other nations such as Italy or France added to the Spanish guitar. All of these nations even imitated the five-course guitar by "recreating" their own.


title: Guitar

text: Finally, circa 1850, the form and structure of the modern guitar are followed by different Spanish makers such as Manuel de Soto y Solares and perhaps the most important of all guitar makers Antonio Torres Jurado, who increased the size of the guitar body, altered its proportions, and invented the breakthrough fan-braced pattern. Bracing, which refers to the internal pattern of wood reinforcements used to secure the guitar's top and back and prevent the instrument from collapsing under tension, is an important factor in how the guitar sounds. Torres' design greatly improved the volume, tone, and projection of the instrument, and it has remained essentially unchanged since.


title: Guitar

text: Guitars can be divided into two broad categories, acoustic and electric guitars. Within each of these categories, there are also further sub-categories. For example, an electric guitar can be purchased in a six-string model (the most common model) or in seven- or twelve-string models.


title: Guitar

text: Acoustic guitars form several notable subcategories within the acoustic guitar group: classical and flamenco guitars; steel-string guitars, which include the flat-topped, or "folk", guitar; twelve-string guitars; and the arched-top guitar. The acoustic guitar group also includes unamplified guitars designed to play in different registers, such as the acoustic bass guitar, which has a similar tuning to that of the electric bass guitar.


title: Guitar

text: Renaissance and Baroque guitars are the ancestors of the modern classical and flamenco guitar. They are substantially smaller, more delicate in construction, and generate less volume. The strings are paired in courses as in a modern 12-string guitar, but they only have four or five courses of strings rather than six single strings normally used now. They were more often used as rhythm instruments in ensembles than as solo instruments, and can often be seen in that role in early music performances. (Gaspar Sanz's "Instrucción de Música sobre la Guitarra Española" of 1674 contains his whole output for the solo guitar.) Renaissance and Baroque guitars are easily distinguished, because the Renaissance guitar is very plain and the Baroque guitar is very ornate, with ivory or wood inlays all over the neck and body, and a paper-cutout inverted "wedding cake" inside the hole.


title: Guitar

text: Classical guitars, also known as "Spanish" guitars, are typically strung with nylon strings, plucked with the fingers, played in a seated position and are used to play a diversity of musical styles including classical music. The classical guitar's wide, flat neck allows the musician to play scales, arpeggios, and certain chord forms more easily and with less adjacent string interference than on other styles of guitar. Flamenco guitars are very similar in construction, but they are associated with a more percussive tone. In Portugal, the same instrument is often used with steel strings particularly in its role within fado music. The guitar is called viola, or violão in Brazil, where it is often used with an extra seventh string by choro musicians to provide extra bass support.


title: Guitar

text: In Mexico, the popular mariachi band includes a range of guitars, from the small "requinto" to the "guitarrón," a guitar larger than a cello, which is tuned in the bass register. In Colombia, the traditional quartet includes a range of instruments too, from the small "bandola" (sometimes known as the Deleuze-Guattari, for use when traveling or in confined rooms or spaces), to the slightly larger tiple, to the full-sized classical guitar. The requinto also appears in other Latin-American countries as a complementary member of the guitar family, with its smaller size and scale, permitting more projection for the playing of single-lined melodies. Modern dimensions of the classical instrument were established by the Spaniard Antonio de Torres Jurado (1817–1892).


title: Guitar

text: Flat-top guitars with steel strings are similar to the classical guitar, however, the flat-top body size is usually significantly larger than a classical guitar, and has a narrower, reinforced neck and stronger structural design. The robust X-bracing typical of flat-top guitars was developed in the 1840s by German-American luthiers, of whom Christian Friedrich "C. F." Martin is the best known. Originally used on gut-strung instruments, the strength of the system allowed the later guitars to withstand the additional tension of steel strings. Steel strings produce a brighter tone and a louder sound. The acoustic guitar is used in many kinds of music including folk, country, bluegrass, pop, jazz, and blues. Many variations are possible from the roughly classical-sized OO and Parlour to the large Dreadnought (the most commonly available type) and Jumbo. Ovation makes a modern variation, with a rounded back/side assembly molded from artificial materials.


title: Guitar

text: Archtop guitars are steel-string instruments in which the top (and often the back) of the instrument are carved, from a solid billet, into a curved, rather than a flat, shape. This violin-like construction is usually credited to the American Orville Gibson. Lloyd Loar of the Gibson Mandolin-Guitar Mfg. Co introduced the violin-inspired "F"-shaped hole design now usually associated with archtop guitars, after designing a style of mandolin of the same type. The typical archtop guitar has a large, deep, hollow body whose form is much like that of a mandolin or a violin-family instrument. Nowadays, most archtops are equipped with magnetic pickups, and they are therefore both acoustic and electric. F-hole archtop guitars were immediately adopted, upon their release, by both jazz and country musicians, and have remained particularly popular in jazz music, usually with flatwound strings.


title: Guitar

text: All three principal types of resonator guitars were invented by the Slovak-American John Dopyera (1893–1988) for the National and Dobro (Dopyera Brothers) companies. Similar to the flat top guitar in appearance, but with a body that may be made of brass, nickel-silver, or steel as well as wood, the sound of the resonator guitar is produced by one or more aluminum resonator cones mounted in the middle of the top. The physical principle of the guitar is therefore similar to the loudspeaker.


title: Guitar

text: The original purpose of the resonator was to produce a very loud sound; this purpose has been largely superseded by electrical amplification, but the resonator guitar is still played because of its distinctive tone. Resonator guitars may have either one or three resonator cones. The method of transmitting sound resonance to the cone is either a "biscuit" bridge, made of a small piece of hardwood at the vertex of the cone (Nationals), or a "spider" bridge, made of metal and mounted around the rim of the (inverted) cone (Dobros). Three-cone resonators always use a specialized metal bridge. The type of resonator guitar with a neck with a square cross-section—called "square neck" or "Hawaiian"—is usually played face up, on the lap of the seated player, and often with a metal or glass slide. The round neck resonator guitars are normally played in the same fashion as other guitars, although slides are also often used, especially in blues.


title: Guitar

text: A steel guitar is any guitar played while moving a polished steel bar or similar hard object against plucked strings. The bar itself is called a "steel" and is the source of the name "steel guitar". The instrument differs from a conventional guitar in that it does not use frets; conceptually, it is somewhat akin to playing a guitar with one finger (the bar). Known for its portamento capabilities, gliding smoothly over every pitch between notes, the instrument can produce a sinuous crying sound and deep vibrato emulating the human singing voice. Typically, the strings are plucked (not strummed) by the fingers of the dominant hand, while the steel tone bar is pressed lightly against the strings and moved by the opposite hand. The instrument is played while sitting, placed horizontally across the player's knees or otherwise supported. The horizontal playing style is called "Hawaiian style".


title: Guitar

text: The twelve-string guitar usually has steel strings, and it is widely used in folk music, blues, and rock and roll. Rather than having only six strings, the 12-string guitar has six courses made up of two strings each, like a mandolin or lute. The highest two courses are tuned in unison, while the others are tuned in octaves. The 12-string guitar is also made in electric forms. The chime-like sound of the 12-string electric guitar was the basis of jangle pop.


title: Guitar

text: The acoustic bass guitar is a bass instrument with a hollow wooden body similar to, though usually somewhat larger than, that of a 6-string acoustic guitar. Like the traditional electric bass guitar and the double bass, the acoustic bass guitar commonly has four strings, which are normally tuned E-A-D-G, an octave below the lowest four strings of the 6-string guitar, which is the same tuning pitch as an electric bass guitar. It can, more rarely, be found with 5 or 6 strings, which provides a wider range of notes to be played with less movement up and down the neck.


title: Guitar

text: Electric guitars can have solid, semi-hollow, or hollow bodies; solid bodies produce little sound without amplification. In contrast to a standard acoustic guitar, electric guitars instead rely on electromagnetic pickups, and sometimes piezoelectric pickups, that convert the vibration of the steel strings into signals, which are fed to an amplifier through a patch cable or radio transmitter. The sound is frequently modified by other electronic devices (effects units) or the natural distortion of valves (vacuum tubes) or the pre-amp in the amplifier. There are two main types of magnetic pickups, single- and double-coil (or humbucker), each of which can be passive or active. The electric guitar is used extensively in jazz, blues, R & B, and rock and roll. The first successful magnetic pickup for a guitar was invented by George Beauchamp, and incorporated into the 1931 Ro-Pat-In (later Rickenbacker) "Frying Pan" lap steel; other manufacturers, notably Gibson, soon began to install pickups in archtop models. After World War II the completely solid-body electric was popularized by Gibson in collaboration with Les Paul, and independently by Leo Fender of Fender Music. The lower fretboard action (the height of the strings from the fingerboard), lighter (thinner) strings, and its electrical amplification lend the electric guitar to techniques less frequently used on acoustic guitars. These include tapping, extensive use of legato through pull-offs and hammer-ons (also known as slurs), pinch harmonics, volume swells, and use of a tremolo arm or effects pedals.


title: Guitar

text: Some electric guitar models feature piezoelectric pickups, which function as transducers to provide a sound closer to that of an acoustic guitar with the flip of a switch or knob, rather than switching guitars. Those that combine piezoelectric pickups and magnetic pickups are sometimes known as hybrid guitars.


title: Guitar

text: Hybrids of acoustic and electric guitars are also common. There are also more exotic varieties, such as guitars with two, three, or rarely four necks, all manner of alternate string arrangements, fretless fingerboards (used almost exclusively on bass guitars, meant to emulate the sound of a stand-up bass), 5.1 surround guitar, and such.


title: Guitar

text: Solid-body seven-string guitars were popularized in the 1980s and 1990s. Other artists go a step further, by using an eight-string guitar with two extra low strings. Although the most common seven-string has a low B string, Roger McGuinn (of The Byrds and Rickenbacker) uses an octave G string paired with the regular G string as on a 12-string guitar, allowing him to incorporate chiming 12-string elements in standard six-string playing. In 1982 Uli Jon Roth developed the "Sky Guitar", with a vastly extended number of frets, which was the first guitar to venture into the upper registers of the violin. Roth's seven-string and "Mighty Wing" guitar features a wider octave range.


title: Guitar

text: The bass guitar (also called an "electric bass", or simply a "bass") is similar in appearance and construction to an electric guitar, but with a longer neck and scale length, and four to six strings. The four-string bass, by far the most common, is usually tuned the same as the double bass, which corresponds to pitches one octave lower than the four lowest pitched strings of a guitar (E, A, D, and G). The bass guitar is a transposing instrument, as it is notated in bass clef an octave higher than it sounds (as is the double bass) to avoid excessive ledger lines being required below the staff. Like the electric guitar, the bass guitar has pickups and it is plugged into an amplifier and speaker for live performances.


title: Guitar

text: Modern guitars can be constructed to suit both left- and right-handed players. Typically the dominant hand is used to pluck or strum the strings. This is similar to the violin family of instruments where the dominant hand controls the bow. Left-handed players usually play a mirror image instrument manufactured especially for left-handed players. There are other options, some unorthodox, including learn to play a right-handed guitar as if the player is right-handed or playing an unmodified right-handed guitar reversed. Guitarist Jimi Hendrix) played a right-handed guitar strung in reverse (the treble strings and bass strings reversed). The problem with doing this is that it reverses the guitar's saddle angle. The saddle is the strip of material on top of the bridge where the strings rest. It is normally slanted slightly, making the bass strings longer than the treble strings. In part, the reason for this is the difference in the thickness of the strings. Physical properties of the thicker bass strings require them to be slightly longer than the treble strings to correct intonation. Reversing the strings, therefore, reverses the orientation of the saddle, adversely affecting intonation.


title: Guitar

text: The headstock is located at the end of the guitar neck farthest from the body. It is fitted with machine heads that adjust the tension of the strings, which in turn affects the pitch. The traditional tuner layout is "3+3", in which each side of the headstock has three tuners (such as on Gibson Les Pauls). In this layout, the headstocks are commonly symmetrical. Many guitars feature other layouts, including six-in-line tuners (featured on Fender Stratocasters) or even "4+2" (e.g. Ernie Ball Music Man). Some guitars (such as Steinbergers) do not have headstocks at all, in which case the tuning machines are located elsewhere, either on the body or the bridge.


title: Guitar

text: The nut is a small strip of bone, plastic, brass, corian, graphite, stainless steel, or other medium-hard material, at the joint where the headstock meets the fretboard. Its grooves guide the strings onto the fretboard, giving consistent lateral string placement. It is one of the endpoints of the strings' vibrating length. It must be accurately cut, or it can contribute to tuning problems due to string slippage or string buzz. To reduce string friction in the nut, which can adversely affect tuning stability, some guitarists fit a roller nut. Some instruments use a zero fret just in front of the nut. In this case the nut is used only for lateral alignment of the strings, the string height and length being dictated by the zero fret.


title: Guitar

text: A guitar's frets, fretboard, tuners, headstock, and truss rod, all attached to a long wooden extension, collectively constitute its neck. The wood used to make the fretboard usually differs from the wood in the rest of the neck. The bending stress on the neck is considerable, particularly when heavier gauge strings are used (see Tuning), and the ability of the neck to resist bending (see Truss rod) is important to the guitar's ability to hold a constant pitch during tuning or when strings are fretted. The rigidity of the neck with respect to the body of the guitar is one determinant of a good instrument versus a poor-quality one.


title: Guitar

text: The cross-section of the neck can also vary, from a gentle "C" curve to a more pronounced "V" curve. There are many different types of neck profiles available, giving the guitarist many options. Some aspects to consider in a guitar neck may be the overall width of the fretboard, scale (distance between the frets), the neck wood, the type of neck construction (for example, the neck may be glued in or bolted on), and the shape (profile) of the back of the neck. Other types of material used to make guitar necks are graphite (Steinberger guitars), aluminum (Kramer Guitars, Travis Bean and Veleno guitars), or carbon fiber (Modulus Guitars and ThreeGuitars). Double neck electric guitars have two necks, allowing the musician to quickly switch between guitar sounds.


title: Guitar

text: The neck joint or heel is the point at which the neck is either bolted or glued to the body of the guitar. Almost all acoustic steel-string guitars, with the primary exception of Taylors, have glued (otherwise known as set) necks, while electric guitars are constructed using both types. Most classical guitars have a neck and headblock carved from one piece of wood, known as a "Spanish heel". Commonly used set neck joints include mortise and tenon joints (such as those used by C. F. Martin & Co.), dovetail joints (also used by C. F. Martin on the D-28 and similar models) and Spanish heel neck joints, which are named after the shoe they resemble and commonly found in classical guitars. All three types offer stability.


title: Guitar

text: Bolt-on necks, though they are historically associated with cheaper instruments, do offer greater flexibility in the guitar's set-up, and allow easier access for neck joint maintenance and repairs. Another type of neck, only available for solid-body electric guitars, is the neck-through-body construction. These are designed so that everything from the machine heads down to the bridge is located on the same piece of wood. The sides (also known as wings) of the guitar are then glued to this central piece. Some luthiers prefer this method of construction as they claim it allows better sustain of each note. Some instruments may not have a neck joint at all, having the neck and sides built as one piece and the body built around it.


title: Guitar

text: The fingerboard, also called the fretboard, is a piece of wood embedded with metal frets that comprises the top of the neck. It is flat on classical guitars and slightly curved crosswise on acoustic and electric guitars. The curvature of the fretboard is measured by the fretboard radius, which is the radius of a hypothetical circle of which the fretboard's surface constitutes a segment. The smaller the fretboard radius, the more noticeably curved the fretboard is. Most modern guitars feature a 12" neck radius, while older guitars from the 1960s and 1970s usually feature a 6-8" neck radius. Pinching a string against a fret on the fretboard effectively shortens the vibrating length of the string, producing a higher pitch.


title: Guitar

text: Fretboards are most commonly made of rosewood, ebony, maple, and sometimes manufactured using composite materials such as HPL or resin. See the section "Neck" below for the importance of the length of the fretboard in connection to other dimensions of the guitar. The fingerboard plays an essential role in the treble tone for acoustic guitars. The quality of vibration of the fingerboard is the principal characteristic for generating the best treble tone. For that reason, ebony wood is better, but because of high use, ebony has become rare and extremely expensive. Most guitar manufacturers have adopted rosewood instead of ebony.


title: Guitar

text: Almost all guitars have frets, which are metal strips (usually nickel alloy or stainless steel) embedded along the fretboard and located at exact points that divide the scale length in accordance with a specific mathematical formula. The exceptions include fretless bass guitars and very rare fretless guitars. Pressing a string against a fret determines the strings' vibrating length and therefore its resultant pitch. The pitch of each consecutive fret is defined at a half-step interval on the chromatic scale. Standard classical guitars have 19 frets and electric guitars between 21 and 24 frets, although guitars have been made with as many as 27 frets. Frets are laid out to accomplish an equal tempered division of the octave. Each set of twelve frets represents an octave. The twelfth fret divides the scale length exactly into two halves, and the 24th fret position divides one of those halves in half again.


title: Guitar

text: The ratio of the spacing of two consecutive frets is formula_1 (twelfth root of two). In practice, luthiers determine fret positions using the constant 17.817—an approximation to 1/(1-1/formula_1). If the nth fret is a distance x from the bridge, then the distance from the (n+1)th fret to the bridge is x-(x/17.817). Frets are available in several different gauges and can be fitted according to player preference. Among these are "jumbo" frets, which have a much thicker gauge, allowing for use of a slight vibrato technique from pushing the string down harder and softer. "Scalloped" fretboards, where the wood of the fretboard itself is "scooped out" between the frets, allow a dramatic vibrato effect. Fine frets, much flatter, allow a very low string-action, but require that other conditions, such as curvature of the neck, be well-maintained to prevent buzz.


title: Guitar

text: The truss rod is a thin, strong metal rod that runs along the inside of the neck. It is used to correct changes to the neck's curvature caused by aging of the neck timbers, changes in humidity, or to compensate for changes in the tension of strings. The tension of the rod and neck assembly is adjusted by a hex nut or an allen-key bolt on the rod, usually located either at the headstock, sometimes under a cover, or just inside the body of the guitar underneath the fretboard and accessible through the sound hole. Some truss rods can only be accessed by removing the neck. The truss rod counteracts the immense amount of tension the strings place on the neck, bringing the neck back to a straighter position. Turning the truss rod clockwise tightens it, counteracting the tension of the strings and straightening the neck or creating a backward bow. Turning the truss rod counter-clockwise loosens it, allowing string tension to act on the neck and creating a forward bow.


title: Guitar

text: Adjusting the truss rod affects the intonation of a guitar as well as the height of the strings from the fingerboard, called the action. Some truss rod systems, called "double action" truss systems, tighten both ways, pushing the neck both forward and backward (standard truss rods can only release to a point beyond which the neck is no longer compressed and pulled backward). The artist and luthier Irving Sloane pointed out, in his book "Steel-String Guitar Construction," that truss rods are intended primarily to remedy concave bowing of the neck, but cannot correct a neck with "back bow" or one that has become twisted. Classical guitars do not require truss rods, as their nylon strings exert a lower tensile force with lesser potential to cause structural problems. However, their necks are often reinforced with a strip of harder wood, such as an ebony strip that runs down the back of a cedar neck. There is no tension adjustment on this form of reinforcement.


title: Guitar

text: Inlays are visual elements set into the exterior surface of a guitar, both for decoration and artistic purposes and, in the case of the markings on the 3rd, 5th, 7th and 12th fret (and in higher octaves), to provide guidance to the performer about the location of frets on the instrument. The typical locations for inlay are on the fretboard, headstock, and on acoustic guitars around the soundhole, known as the rosette. Inlays range from simple plastic dots on the fretboard to intricate works of art covering the entire exterior surface of a guitar (front and back). Some guitar players have used LEDs in the fretboard to produce unique lighting effects onstage. Fretboard inlays are most commonly shaped like dots, diamond shapes, parallelograms, or large blocks in between the frets.


title: Guitar

text: Dots are usually inlaid into the upper edge of the fretboard in the same positions, small enough to be visible only to the player. These usually appear on the odd-numbered frets, but also on the 12th fret (the one-octave mark) instead of the 11th and 13th frets. Some older or high-end instruments have inlays made of mother of pearl, abalone, ivory, colored wood or other exotic materials and designs. Simpler inlays are often made of plastic or painted. High-end classical guitars seldom have fretboard inlays as a well-trained player is expected to know his or her way around the instrument. In addition to fretboard inlay, the headstock and soundhole surround are also frequently inlaid. The manufacturer's logo or a small design is often inlaid into the headstock. Rosette designs vary from simple concentric circles to delicate fretwork mimicking the historic rosette of lutes. Bindings that edge the finger and soundboards are sometimes inlaid. Some instruments have a filler strip running down the length and behind the neck, used for strength or to fill the cavity through which the truss rod was installed in the neck.


title: Guitar

text: In acoustic guitars, string vibration is transmitted through the bridge and saddle to the body via sound board. The sound board is typically made of tonewoods such as spruce or cedar. Timbers for tonewoods are chosen for both strength and ability to transfer mechanical energy from the strings to the air within the guitar body. Sound is further shaped by the characteristics of the guitar body's resonant cavity. In expensive instruments, the entire body is made of wood. In inexpensive instruments, the back may be made of plastic.


title: Guitar

text: In an acoustic instrument, the body of the guitar is a major determinant of the overall sound quality. The guitar top, or soundboard, is a finely crafted and engineered element made of tonewoods such as spruce and red cedar. This thin piece of wood, often only 2 or 3 mm thick, is strengthened by differing types of internal bracing. Many luthiers consider the top the dominant factor in determining the sound quality. The majority of the instrument's sound is heard through the vibration of the guitar top as the energy of the vibrating strings is transferred to it. The body of an acoustic guitar has a sound hole through which sound projects. The sound hole is usually a round hole in the top of the guitar under the strings. The air inside the body vibrates as the guitar top and body is vibrated by the strings, and the response of the air cavity at different frequencies is characterized, like the rest of the guitar body, by a number of resonance modes at which it responds more strongly.


title: Guitar

text: The top, back and ribs of an acoustic guitar body are very thin (1–2 mm), so a flexible piece of wood called lining is glued into the corners where the rib meets the top and back. This interior reinforcement provides 5 to 20 mm of solid gluing area for these corner joints. Solid linings are often used in classical guitars, while kerfed lining is most often found in steel-string acoustics. Kerfed lining is also called kerfing because it is scored, or "kerfed"(incompletely sawn through), to allow it to bend with the shape of the rib). During final construction, a small section of the outside corners is carved or routed out and filled with binding material on the outside corners and decorative strips of material next to the binding, which is called purfling. This binding serves to seal off the end grain of the top and back. Purfling can also appear on the back of an acoustic guitar, marking the edge joints of the two or three sections of the back. Binding and purfling materials are generally made of either wood or plastic.


title: Guitar

text: Body size, shape and style have changed over time. 19th-century guitars, now known as salon guitars, were smaller than modern instruments. Differing patterns of internal bracing have been used over time by luthiers. Torres, Hauser, Ramirez, Fleta, and C. F. Martin were among the most influential designers of their time. Bracing not only strengthens the top against potential collapse due to the stress exerted by the tensioned strings but also affects the resonance characteristics of the top. The back and sides are made out of a variety of timbers such as mahogany, Indian rosewood and highly regarded Brazilian rosewood ("Dalbergia nigra"). Each one is primarily chosen for their aesthetic effect and can be decorated with inlays and purfling.


title: Guitar

text: Instruments with larger areas for the guitar top were introduced by Martin in an attempt to create greater volume levels. The popularity of the larger "dreadnought" body size amongst acoustic performers is related to the greater sound volume produced.