Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. The source of the heat that liquifies the rock within the earth is geothermal energy. When first erupted from a volcanic vent, lava is a liquid at temperatures from 700 to 1,200 °C (1,292 to 2,192 °F). Up to 100,000 times as viscous as water, lava can flow great distances before cooling and solidifying because of its thixotropic and shear thinning properties.
A lava flow is a moving outpouring of lava, which is created during a non-explosiveeffusive eruption. When it has stopped moving, lava solidifies to form igneous rock. The term lava flow is commonly shortened to lava. Explosive eruptions produce a mixture ofvolcanic ash and other fragments called tephra, rather than lava flows. The word "lava" comes from Italian, and is probably derived from the Latin word labes which means a fall or slide.The first use in connection with extruded magma (molten rock below the Earth's surface) was apparently in a short account written by Francesco Serao on the eruption of Vesuvius between May 14 and June 4, 1737.Serao described "a flow of fiery lava" as an analogy to the flow of water and mud down the flanks of the volcano following heavy rain.
Hip hop is a broad conglomerate of artistic forms that originated within a marginalizedsubculture in the South Bronx and Harlem in New York City among black and Latino youth during the 1970s.It is characterized by four distinct elements, all of which represent the different manifestations of the culture: rap music (oral), turntablism or "DJing" (aural),breaking (physical) and graffiti art (visual). Despite their contrasting methods of execution, they find unity in their common association to the poverty and violence underlying the historical context that birthed the culture. It was as a means of providing a reactionary outlet from suchurban hardship that "hip hop" initially functioned, a form of self-expression that could reflect upon, proclaim an alternative to, try to challenge or merely evoke the mood of the circumstances of such an environment. Even while it continues in contemporary history to develop globally in a flourishing myriad of diverse styles, these foundational elements provide stability and coherence to the culture.The term is frequently used mistakenly to refer in a confining fashion to the mere practice of rap music.
The origin of the culture stems from the block parties of the Ghetto Brothers when they plugged the amps for their instruments and speakers into the lampposts on 163rd Street and Prospect Avenue, and from DJ Kool Herc at 1520 Sedgwick Avenue, where Herc mixed samples of existing records with his own shouts to the crowd and dancers. Kool Herc is credited as the "father" of hip hop. DJ Afrika Bambaataa of the hip hop collective Zulu Nation outlined the pillars of hip hop culture, to which he coined the terms: MCing or "Emceein", DJing or "Deejayin", B-boying and graffiti writing or "Aerosol Writin".
Since its evolution throughout the South Bronx, hip hop culture has spread to both urban and suburban communities throughout the world.Hip hop music first emerged with Kool Herc and contemporary disc jockeys and imitators creating rhythmic beats by loopingbreaks (small portions of songs emphasizing a percussive pattern) on two turntables. This was later accompanied by "rap", a rhythmic style of chanting or poetry often presented in 16-bar measures or time frames, and beatboxing, a vocal technique mainly used to provide percussive elements of music and various technical effects of hip hop DJs. An original form of dancing and particular styles of dress arose among fans of this new music. These elements experienced considerable adaptation and development over the course of the history of the culture.
Hip hop is simultaneously a new and old phenomenon; the importance of sampling to the art form means that much of the culture has revolved around the idea of updating classic recordings, attitudes, and experiences for modern audiences—called "flipping" within the culture. It follows in the footsteps of earlier American musical genres such as blues, salsa, jazz, and rock and roll in having become one of the most practiced genres of music in existence worldwide, and also takes additional inspiration regularly from soul music, funk, andrhythm and blues.
Saint Valentine's Day, also known as Valentine's Day or the Feast of Saint Valentine,is observed on February 14 each year. It is celebrated in many countries around the world, although it is not a holiday in most of them.
St. Valentine's Day began as a liturgical celebration of one or more early Christian saints named Valentinus. Several martyrdom stories were invented for the various Valentines that belonged to February 14, and added to later martyrologies.A popular hagiographical account of Saint Valentine of Rome states that he was imprisoned for performing weddings for soldiers who were forbidden to marry and for ministering to Christians, who were persecuted under the Roman Empire. According to legend, during his imprisonment, he healed the daughter of his jailer, Asterius. An embellishment to this story states that before his execution he wrote her a letter signed "Your Valentine" as a farewell.Today, Saint Valentine's Day is an official feast day in the Anglican Communion,as well as in the Lutheran Church.The Eastern Orthodox Church also celebrates Saint Valentine's Day, albeit on July 6 and July 30, the former date in honor of the Roman presbyter Saint Valentine, and the latter date in honor of HieromartyrValentine, the Bishop of Interamna (modern Terni). In Brazil, the Dia de São Valentim is recognized on June 12.