The Doppler effect is the change in frequency of a wave in relation to an observer, moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842. A common example of Doppler shift is the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer. Compared to the emitted frequency, the received frequency is higher during the approach, identical at the instant of passing by, lower during the recession; the reason for the Doppler effect is that when the source of the waves is moving towards the observer, each successive wave crest is emitted from a position closer to the observer than the crest of the previous wave. Therefore, each wave takes less time to reach the observer than the previous wave. Hence, the time between the arrivals of successive wave crests at the observer is reduced, causing an increase in the frequency. While they are traveling, the distance between successive wave fronts is reduced, so the waves "bunch together".

Conversely, if the source of waves is moving away from the observer, each wave is emitted from a position farther from the observer than the previous wave, so the arrival time between successive waves is increased, reducing the frequency. The distance between successive wave fronts is increased, so the waves "spread out". For waves that propagate in a medium, such as sound waves, the velocity of the observer and of the source are relative to the medium in which the waves are transmitted; the total Doppler effect may therefore result from motion of the source, motion of the observer, or motion of the medium. Each of these effects is analyzed separately. For waves which do not require a medium, such as light or gravity in general relativity, only the relative difference in velocity between the observer and the source needs to be considered. Doppler first proposed this effect in 1842 in his treatise "Über das farbige Licht der Doppelsterne und einiger anderer Gestirne des Himmels"; the hypothesis was tested for sound waves by Buys Ballot in 1845.

He confirmed that the sound's pitch was higher than the emitted frequency when the sound source approached him, lower than the emitted frequency when the sound source receded from him. Hippolyte Fizeau discovered independently the same phenomenon on electromagnetic waves in 1848. In Britain, John Scott Russell made an experimental study of the Doppler effect. In classical physics, where the speeds of source and the receiver relative to the medium are lower than the velocity of waves in the medium, the relationship between observed frequency f and emitted frequency f 0 is given by: f = f 0 where c is the propagation speed of waves in the medium. Note this relationship predicts that the frequency will decrease if either source or receiver is moving away from the other. Equivalent formula, easier to remember: f v w r = f 0 v w s = 1 λ where v w r is the wave's velocity relative to the receiver; the above formula assumes that the source is either directly approaching or receding from the observer.

If the source approaches the observer at an angle, the observed frequency, first heard is higher than the object's emitted frequency. Thereafter, there is a monotonic decrease in the observed frequency as it gets closer to the observer, through equality when it is coming from a direction perpendicular to the relative motion, a continued monotonic decrease as it recedes from the observer; when the observer is close to the path of the object, the transition from high to low frequency is abrupt. When the observer is far from the path of the object, the transition from high to low frequency is gradual. If the speeds v s and v r are small compared to the speed of the wave, the relationship between observed frequency f {\displaysty

The Sidgwick Site is one of the largest sites within the University of Cambridge, England. The Sidgwick Site is located on the western side near the College backs; the site is north of Sidgwick Avenue and south of West Road, is home to several of the university's arts and humanities faculties. The site is named after the philosopher Henry Sidgwick, who studied at Cambridge in the 19th century; the site as it is now has its origins in plans drawn up by Casson and Conder in 1952 for making use of land to the west of the Cambridge city centre, used for sports. Much of the site's current architecture derives from these original plans. However, many faculty buildings to the north of the site, have been designed by separate architects with little reference to the coherence of the site as a whole. In July 2002, the old Faculty of English, a converted Victorian villa, was demolished, a more practical building designed by Allies and Morrison to reflect the needs of the faculty was completed in 2004; the Alison Richard Building, completed in 2012 and designed by Nicholas Hare Architects, brings together a number of different research groups, the new department of Politics and International Studies and the Centre for Research in Arts, Social Sciences and Humanities.

On 29 October 2006, Education Not For Sale supporters at Cambridge University organised the first occupation in the UK in protest at the introduction of top-up fees on the Sidgwick Site Lecture Hall, occupying it for 12 hours. In 2009, Cambridge Gaza Solidarity occupied three lecture theatres and the common area of the Law Faculty. Although less popular now, the site was a thriving location with the local skateboarding community because of its undercover benches, numerous sets of stairs and L-shaped concrete banks; these features have since been amended to discourage skateboarding. The following University of Cambridge faculties and departments are located on the site: Faculty of Asian and Middle Eastern Studies Faculty of Classics with the Museum of Classical Archaeology Faculty of English, incorporating the Anglo-Saxon and Celtic Faculty of Music Faculty of History Faculty of Law Department of Politics and International Studies Faculty of Modern & Medieval Languages Faculty of Economics Faculty of Divinity Faculty of Philosophy Institute of Criminology Centre of Latin American StudiesThe Department of Land Economy is planned to move to the Sidgwick Site.

The site has a buttery which sells snacks and drinks throughout the day with seating inside and a number of picnic tables outside. There is an Origin8 which offers a soup of the day, hot panini and wraps, sandwiches and various drinks, a number of food and drink machines along with seating in basement of the Law faculty building; the Modern & Medieval Languages faculty has tea/coffee machines on a snack machine. There is a student prayer room on the Sidgwick Site located at the back of Lecture Block A. Here, the University Islamic Society holds Jamaat five times a day. Lady Mitchell Hall, a large lecture theatre on the site Map

The 50,000 Colombian peso note is the second highest denomination of Colombian currency. Designed by Óscar Muñoz, the front of the notes feature Jorge Isaacs and the heroine of his novel María, the back of the notes feature an Albizia saman tree, two palm trees, an image of Isaacs' house El Paraiso, an excerpt from María. In June 2013, the Bank of the Republic of Colombia estimated that 602,500,000 notes of the 50,000 denomination were in circulation, it was first printed on 1 December 2000, contains many safety features such as a watermark, ultra-violet ink, a holographic strip, microprinting. Measuring 140 by 70 millimetres, each note is made of cotton fibre; until 1870, there were no banks in Colombia. Coins made of gold, silver and copper were in circulation but no notes were issued, given the underdeveloped monetary system of Colombia; the Banco de Bogotá was the first private bank to be established in Colombia, in 1870. From 1871 to 1886, thirty-six private banks issued notes under Act 35.

However, in 1886, President Rafael Núñez declared notes produced by Banco Nacional as Colombia's legal tender. After its creation in 1923, the Bank of the Republic was established as Colombia's main bank, the only one permitted to issue currency. Between 1923 and 1931, denominations of 1, 2, 5, 10, 20, 50, 100 and 500 peso notes were put into circulation, which were able to be exchanged for gold or United States dollars. After the 1930s, these notes ceased to be convertible into gold but remained in circulation until the mid 1970s, when they were replaced by copper and nickel coins; these coins were manufactured until 1991 by the General Treasury of the Nation. The printing of the notes of the Bank of the Republic of Colombia was inaugurated on 23 October 1959, the 50,000 peso note was first printed in 2000; the 50,000 peso note is the highest denomination of currency in Colombia, measures 140mm by 70mm. The illustrations are presented vertically, the note was designed by Óscar Muñoz. On the front side of the note, the main colours are purple and yellow, it features an image of writer and poet Jorge Isaacs, with a background of the Cauca River in Valle del Cauca.

The heroine of his novel María is shown, an image, inspired a monument by Luis A. Parera. "50" is written in Braille. On the front of the note is the name of the currency, the country, the name of the Bank of the Republic; the reverse of the note features an Albizia saman tree, characteristic to the region of Valle del Cauca, an image of Isaacs' house El Paraiso, which he purchased in 1854 and resided in during his adolescence. This side is predominantly purple and yellow, contains the logo of the Bank of the Republic. Two palm trees are printed on the reverse, behind them is a paragraph from María about the evening atmosphere in Valle del Cauca: Una tarde, tarde como las de mi país, engalanada con nubes de color violeta y lampos de oro pálido, bella como María, bella y transitoria como fue ésta para mí, ella, mi hermana y yo, sentados sobre la ancha piedra de la pendiente, desde donde veíamos a la derecha en la honda vega rodar las corrientes bulliciosas del río, y teniendo a nuestros pies el valle majestuoso y callado, leía yo el episodio de Atala, y las dos, admirables en su inmovilidad y abandono.

Since the initial printing of the 50,000 peso note, there have been nineteen editions of it: The notes have two security threads, the first being an opaque band, the second being the text "50 MIL PESOS COLOMBIA" which can be seen under direct light. There is a watermark of Jorge Isaacs' face, along with many examples of relief printing. Under ultraviolet light, the note appears to be orange with yellow fibrils, it is protected by a serial number, various microprinting and colour-shifting ink is used on the front for the number 50. On both sides of the note, there are books shown on the notes with blank areas of colour; when the note is viewed by transparency, these areas coincide with the ones on the other side of the note. As of March 2010, the production cost of each 50,000 peso note is 103 pesos. In comparison, a 1,000 peso note costs 57 pesos to produce, given that it does not have as many safety devices. Notes in poor condition are sent to the Central Treasury; the manufacturing process of each note takes 28 days, each note will stay in circulation for 34 months.

Despite other countries adopting laminated notes for greater durability, Colombia has decided not to in order to attempt to prevent counterfeit notes

Institute of Hotel Management Catering & Nutrition, New Delhi known as IHM Pusa, is a hospitality management school located in Delhi, India. IHM Pusa is situated in New Delhi. IHM Pusa is known to be the top hotel management institute in the country for the last 5 years in a row because of its placements, faculty and students; the Institute is governed by the National Council for Hotel Management & Catering Technology set up by the Ministry of Tourism, Govt. of India. This Institute is the second Government institute to start in 1962 under the Ministry of food after the Dadar Catering College, Bombay, it was started by the Government Of India under the guidance of Sir Belfield Smith in Pusa, New Delhi in the abandoned barracks behind present employment exchange building. 3 years Generic BSc HHA. 2 years MSc HHA. 2 years MSc D&FSM. 1 year PGDAOM. 1 year DFBS. 1 year DBC. 1 year CCFP. The Institute has been ranked as the number one Hotel Management institute in India by Ministry of Tourism, Government of India for the past few years.

It is ranked as the top hotel management institute by news agencies like Outlook and Hindustan Times. There has been a tough competition between IHM Mumbai and IHM Pusa for the first place in the past but both are the best institutes of hotel management in India and are unique in their own ways. In 2016, three IHMCTANs - Ahmedabad and Jaipur - started giving a student the option to choose only vegetarian cooking. In 2018, the National Council for Hotel Management announced that all IHMs will provide a vegetarian option beginning academic year 2018; this decision to offer a vegetarian option by IHMCTANs may be the first amongst any of the hospitality training institutes of the world. IHMCTAN at Pusa had been experimenting with vegan cooking through "vegan months" and sustainability practices such as rainwater harvesting. IHM Mumbai, Maharashtra IHM Hyderabad, Telangana IHM Chennai, Tamil Nadu IHM Bangalore, Karnataka IHM Kolkata, West Bengal IHM Goa, Goa IHM Ahmedabad, Gujarat IHM Bhopal, Madhya Pradesh IHM Lucknow, Uttar Pradesh IHM Hajipur, Bihar IHM Chandigarh, Chandigarh IHM Jaipur, Rajasthan IHM Guwahati, Assam IHM Bhubaneshwar, Orissa IHM Shimla, Himachal Pradesh IHM Srinagar and Kashmir IHM Gurdaspur, Punjab IHM Trivandrum, Kerala IHM Meerut, Uttar Pradesh IHM Rohtak IHM Pusa

Well Worn Daffy is a 1965 Looney Tunes animated short featuring Daffy Duck and Speedy Gonzales in a struggle for a well. Speedy Gonzales and his two mouse companions are lost in the desert dying of thirst when they happen upon a well. However, they shortly discover Daffy is the owner, he refuses to give them any water, despite their desperate pleas After shooting at them and his friends are forced to watch Daffy and his camel not only drink, but shower and water the trees. Speedy devises a plan to lure Daffy away from the well while his friends get some water, but the camel booby-traps it. Speedy tries again and when Daffy shoots at him, he somehow knocks a tree down on himself; the mice's further attempts are foiled by either Daffy shooting the cup full of holes or the camel tripping Speedy. A last attempt involves Speedy traveling underground with the hose, only to have Daffy come out the end and shoot them again. Daffy packs his camel with as much water as needed for a journey home and loads the well with dynamite so the mice cannot have any.

Speedy ties the string of dynamite to Daffy's camel so the well is safe. Speedy and his friends drink as much as they can, soon Daffy and his camel come along begging for water, due to how when they realized that Speedy had tied the dynamite string to them, in their panic, they dumped all the water they had packed in fright. Speedy obliges by spraying him down. Daffy replies, "There's one thing worse than a smart mouse, that's three smart mice." Director: Robert McKimson Story: David Detiege Animation: Don Williams, Manny Perez, Warren Batchelder, Bob Matz, Laverne Hardling, Norm McCabe Layout: Dick Ung Backgrounds: Tom O'Loughlin Film Editor: Lee Gunther Voice Characterizations: Mel Blanc Music: Bill Lava Produced by: David H. DePatie and Friz Freleng Well Worn Daffy on IMDb

In mathematical physics, the Duffin–Kemmer–Petiau algebra, introduced by R. J. Duffin, Nicholas Kemmer and G. Petiau, is the algebra, generated by the Duffin–Kemmer–Petiau matrices; these matrices form part of the Duffin–Kemmer–Petiau equation that provides a relativistic description of spin-0 and spin-1 particles. The DKP algebra is referred to as the meson algebra; the Duffin–Kemmer–Petiau matrices have the defining relation β a β b β c + β c β b β a = β a η b c + β c η b a where η a b stand for a constant diagonal matrix. The Duffin–Kemmer–Petiau matrices β for which η a b consists in diagonal elements form part of the Duffin–Kemmer–Petiau equation. Five-dimensional DKP matrices can be represented as: β 0 =, β 1 =, β 2 =, β 3 = These five-dimensional DKP matrices represent spin-0 particles; the DKP matrices for spin-1 particles are 10-dimensional. The DKP-algebra can be reduced to a direct sum of irreducible subalgebras for spin‐0 and spin‐1 bosons, the subalgebras being defined by multiplication rules for the linearly independent basis elements.

The Duffin–Kemmer–Petiau equation is a relativistic wave equation which describes spin-0 and spin-1 particles in the description of the standard model. For particles with nonzero mass, the DKP equation is ψ = 0 where β a are Duffin–Kemmer–Petiau matrices, m is the particle's mass, ψ its wavefunction, ℏ the reduced Planck constant, c the speed of light. For massless particles, the term m c is replaced by a singular matrix γ that obeys the relations β a γ + γ β a = β a and γ 2 = γ; the DKP equation for spin-0 is linked to the Klein–Gordon equation. And the equation for spin-1 to the Proca equations It suffers the same drawback as the Klein–Gordon equation in that it calls for negative probabilities; the De Donder–Weyl covariant Ham