In physics, a standing wave known as a stationary wave, is a wave which oscillates in time but whose peak amplitude profile does not move in space. The peak amplitude of the wave oscillations at any point in space is constant with time, the oscillations at different points throughout the wave are in phase; the locations at which the amplitude is minimum are called nodes, the locations where the amplitude is maximum are called antinodes. Standing waves were first noticed by Michael Faraday in 1831. Faraday observed standing waves on the surface of a liquid in a vibrating container. Franz Melde coined the term "standing wave" around 1860 and demonstrated the phenomenon in his classic experiment with vibrating strings; this phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interference between two waves traveling in opposite directions. The most common cause of standing waves is the phenomenon of resonance, in which standing waves occur inside a resonator due to interference between waves reflected back and forth at the resonator's resonant frequency.

For waves of equal amplitude traveling in opposing directions, there is on average no net propagation of energy. As an example of the first type, under certain meteorological conditions standing waves form in the atmosphere in the lee of mountain ranges; such waves are exploited by glider pilots. Standing waves and hydraulic jumps form on fast flowing river rapids and tidal currents such as the Saltstraumen maelstrom. Many standing river waves are popular river surfing breaks; as an example of the second type, a standing wave in a transmission line is a wave in which the distribution of current, voltage, or field strength is formed by the superposition of two waves of the same frequency propagating in opposite directions. The effect is a series of anti-nodes at fixed points along the transmission line; such a standing wave may be formed when a wave is transmitted into one end of a transmission line and is reflected from the other end by an impedance mismatch, i.e. discontinuity, such as an open circuit or a short.

The failure of the line to transfer power at the standing wave frequency will result in attenuation distortion. In practice, losses in the transmission line and other components mean that a perfect reflection and a pure standing wave are never achieved; the result is a partial standing wave, a superposition of a standing wave and a traveling wave. The degree to which the wave resembles either a pure standing wave or a pure traveling wave is measured by the standing wave ratio. Another example is standing waves in the open ocean formed by waves with the same wave period moving in opposite directions; these may form near storm centres, or from reflection of a swell at the shore, are the source of microbaroms and microseisms. In one dimension, two waves with the same wavelength and amplitude, traveling in opposite directions will interfere and produce a standing wave. For example, a wave traveling to the right along a taut string held stationary at its right end will reflect back in the other direction along the string, the two waves will superpose to produce a standing wave.

To create a standing wave, the two oppositely directed waves must have the same amplitude and frequency. The phenomenon can be demonstrated mathematically by deriving the equation for the sum of two oppositely moving waves: A harmonic wave traveling to the right along the x-axis is described by the equation y 1 = A sin ⁡ An identical harmonic wave traveling to the left is described by the equation y 2 = A sin ⁡ where: A is the amplitude of the wave, ω is 2π times the frequency λ is the wavelength of the wave x and t are variables for longitudinal position and time, respectively. So the equation of the resultant wave y will be the sum of y1 and y2: y = y 1 + y 2 = A sin ⁡ + A sin ⁡ Using the trigonometric sum-to-product identity sin ⁡ a + sin ⁡ b = 2 sin ⁡ cos ⁡ ( a

The New Adventures of Gilligan is an American Saturday morning animated series produced by Filmation and was aired on ABC during the 1974–1977 seasons. The New Adventures of Gilligan was based on the 1964–1967 CBS television series Gilligan's Island and featured all of the characters from that show. Most of the original cast reprised their roles and provided their voices for the animated series, with the exception of Tina Louise and Dawn Wells. Louise wanted to distance herself from the role of Ginger Grant and Wells was on the road in a play and unavailable. Actress Jane Webb provided the voice for both Ginger and Mary Ann, credited under her married name for Mary Ann and her maiden name for Ginger; the overall storyline of the animated series was the same as the original live-action show, the plots of the individual episodes were similar to those of the original series. A first mate and his skipper set out on a three-hour tour with five passengers and end up stranded on an uncharted desert isle.

The one change was the introduction of Stubby, an anthropomorphic monkey, befriended by Gilligan. Much like other Filmation series at the time, the stories were more aimed at children and contained a moral lesson. Bob Denver as Willy Gilligan Alan Hale Jr. as Skipper Jonas Grumby Jim Backus as Thurston Howell III Natalie Schafer as Eunice Wentworth "Lovey" Howell Russell Johnson as Professor Roy Hinkley Jane Webb as Ginger Grant, Mary Ann Summers Lou Scheimer as Stubby The series was produced by Filmation Associates, who first approached Sherwood Schwartz to license the show back in 1971 and they tried again in 1972 and 1973. However, according to Filmation co-founder Lou Scheimer, Schwartz was in the middle of trying to revive the live-action series and declined to have the show adapted into a cartoon. However, by 1974, after failing to sell a Gilligan's Island revival to any of the networks, Schwartz agreed to license the show, on condition that he was allowed to have great creative input, including hands-on supervision of not only the scripts, but the storyboards as well.

Like the original series, The New Adventures of Gilligan contained an adult laugh track, common practice with most Saturday-morning cartoons of the era. One unique feature of Gilligan was the fact that it was produced and animated in the United States, where most shows at that time were animated overseas in order to cut production costs. However, Filmation's dedication to having its shows produced locally did not help the production values, as many felt the animation of Gilligan was of poor quality; as the series did not secure the rights to "The Ballad of Gilligan's Isle," a spoken-word poem with lyrics and backing music vaguely reminiscent of the theme was substituted as the opening introduction. All of the voice actors except for Bob Denver read portions of the poem; the show debuted on ABC Saturday morning on September 7, 1974. After 24 episodes over two seasons, ABC relegated the show to Sunday mornings for a third and final season of repeats in 1976–77; the network, still reeling from the ratings disaster in 1975–76 connected with Uncle Croc's Block, was reluctant to order another season of animated Gilligan installments or anything new from Filmation Associates.

In 1982, another Gilligan's Island-based animated series was created, this time entitled Gilligan's Planet. The premise for that series centered around the castaways creating a spaceship and winding up on a deserted planet; the series is owned by Turner Entertainment Co. rather than Filmation successor Universal Television, due to the show being a part of the pre-1986 Metro-Goldwyn-Mayer library. The premiere episode of The New Adventures of Gilligan, "Off Limits," was released as part of Warner Home Video's Saturday Morning Cartoons – 1970s Volume 2 on October 27, 2009; the complete series was scheduled to be released on DVD in the spring of 2011, but was pushed back. On April 26, 2016, The New Adventures of Gilligan: The Complete Series was released on DVD in region 1 as part of the Warner Archive Collection; this is a manufacture-on-demand release, available through Warner's online store. The series is available at the iTunes Store. List of animated spinoffs from prime time shows The New Adventures of Gilligan on IMDb The New Adventures of Gilligan at the Big Cartoon DataBase TVSeriesFinale.com article on last episode.

Includes series opening and closing

The Câlnic Citadel is a citadel located in Câlnic, Alba County, in the Transylvania region of Romania. It was built by a nobleman whose family sold it to the local ethnic German Transylvanian Saxon community at a time when the area belonged to the Kingdom of Hungary; when still used for defensive purposes, the double walls encompassed a residential keep, storerooms and a Roman Catholic chapel that became Lutheran following the Reformation. Together with the surrounding village, the citadel forms part of the villages with fortified churches in Transylvania UNESCO World Heritage Site; the Mongol invasion of 1241 prompted a surge in military construction in Transylvania, with wood and earthen defenses abandoned in favor of stone, assembled in haste and without much initial attention to artistic detail. At Câlnic, the citadel began as a residence for a Graf, one of the last such to be built in Transylvania. Around 1270, the nobleman Chyl de Kelling, whose family gave the village its German name, built a keep for his residence.

The strong parallelepiped structure, with a ground floor and three floors for living space, came to be known as the Siegfried tower. Frequent Ottoman attacks led the keep to be fortified with a defensive level and surrounded by a massive wall; the oval precinct around the keep was fitted with a guard tower to the south and a gate tower to the north. The structure was surrounded with access only by drawbridge; the noble owners never went along well with the local notables, in 1430, the final Graf sold the citadel to the villagers and moved away. Once the Saxon community took ownership, they extended it by building a second fortification wall and a tower in the southern part, using the structure for refuge during Ottoman raids. Within were built storerooms and living quarters for withstanding sieges. After the second wall was finished in the 16th century, two levels were added to the keep so that defenders could fire guns outside the wall precincts. At the end of the 15th century, a small hall church-type chapel with an apse was built for the fort on the site of an earlier, ruined sacred building.

The chapel interior features fresco fragments from the beginning of the 16th century. Its western side has a wooden platform decorated with panels painted in 1733 in a floral, folk-Renaissance style. In the mid-16th century, the moat was filled and the drawbridge replaced by a gatehouse fitted with a portcullis; the Ottomans failed to take the citadel. Restoration work was done between 1961 and 1964. Since 1995, the site has been administered by a foundation of Babeș-Bolyai University in Cluj-Napoca; the tower hosts a museum detailing the local Saxons' lifestyle and traditions, while the chapel hosts lectures. Nearby, there is a former Lutheran parish house built in the 16th century and enlarged in 1779. Villagers built the church in the 15th century, although it was much altered in the 19th century and now has a Gothic Revival style, its two tabernacles and the sacristy portal are original carved Gothic items, while two Baroque pulpits are from the second part of the 18th century. In 1999, Câlnic, together with five other places, was added to the already-listed Biertan to form the villages with fortified churches in Transylvania UNESCO World Heritage Site.

Additionally, the citadel is listed as a historic monument by Romania's Ministry of Culture and Religious Affairs, the following considered separate monuments: the keep, the chapel, the inner wall, the outer wall, the church and the parish house