It then becomes possible to always keep the file system in a consistent state. With databases, this is known as ACID. That way, an operation on a file is either done, or it is not done. There are however, no states in between. The file being written to the filesystem is no longer visible. This is usually done using transactions. But with filesystems, it is called "journaling".
David II of Scotland
David II (5 March 1324 – 22 February 1371) King of Scots, son of King Robert the Bruce by his second wife, Elizabeth de Burgh (d. 1327), was born at Dunfermline Palace, Fife.
He was married on 17 July 1328, aged only four, to Joan of the Tower (d. 1362), daughter of Edward II of England and Isabella of France.
At the age of five, David became King of Scotland after the death of his father on 7 June 1329. He was crowned at Scone in November 1331.
Edward Balliol, with support from Edward III of England fought against David, so that he could become king. He defeated David at the Battle of Dupplin on 12 August 1332. Balliol was crowned king, and in July 1333, the nine year old David and his queen were sent to France for their safety. In June 1341 he came back and began to rule. In 1346 he invaded England, but was defeated and taken prisoner at the Battle of Neville's Cross on 17 October 1346, and remained in England for eleven years, living mainly in London and at Odiham in Hampshire. In October 1357 he was allowed to go back to Scotland for a payment of 100,000 marks. The money was never paid completely.
In 1371 David died in Edinburgh Castle.
Lied
Lied (pronounced “leed”) is the German word for “song” (the plural is Lieder – pronounced “leader”).
The word Lied is used in music to describe the songs that were written by German-speaking composers of classical music. Songs composed by classical composers are sometimes called “art songs”.
Lieder are normally songs for a singer with piano accompaniment. They were mostly composed in the 19th century which was the period known as the Romantic period. The most famous composers of Lieder were Franz Schubert, Robert Schumann, Johannes Brahms, Hugo Wolf and Richard Strauss.
In German culture the Lied as an art song goes back to the Middle Ages. Walther von der Vogelweide was a 12th-13th century minnesinger who composed and sang songs for important people at the royal court. Like most minnesinger, he was a poet as well as a composer, writing words for his own songs.
The Lied in the Romantic period was usually written by two different people: the poet wrote the words and then the composer “set the words” to music. 19th century composers mostly took great care to choose good poetry for their songs. The poetry was often by famous poets such as Goethe and Schiller.
Although most Lieder were composed in the Romantic period, the beginnings were there in the Classical music period. Mozart wrote a song called "Das Veilchen" ("The Violet") and Beethoven wrote several songs.
It was Schubert who was to be the greatest of all Lieder composers. Schubert wrote over 600 songs. Very often he wrote in a form which had been used by Walther von der Vogelweide: three verses of which the first two have the same music (A-A-B, or as von der Vogelweide called them: “Stollen, Stollen, Abgesang”). Other songs of his are what is known as “durchkomponiert” (“through composed”). Here each verse is different, so that the composer can express the words of each verse with different music. The wonderful thing about Schubert’s songs is the way in which the piano accompaniments help the voice and show the meaning of the words. The piano was a fairly new instrument at the time and could do things that would have been impossible on the harpsichord. One of his earliest songs is the famous "Erlkönig" ("Erlking"). The piano accompaniment is very difficult to play because the right hand has continuous repeated octaves which describe the galloping of the horse in the wild, stormy night. "Grettchen am Spinnrade" is a song which sets a poem from "Goethe's Faust". The young girl is sitting at the spinning-wheel thinking of her lover. The piano has a rippling accompaniment which sounds like the gentle clatter of the spinning-wheel. At the moment when the girl imagines her lover's kiss the piano part comes to a stop, then gradually starts up again as the girl wakes up to the world around her.
Composers often composed groups of songs which belong together. These are called a “song cycle” (“Liederkreis” in German). Schubert wrote two long ones: "Die Winterreise" ("The Winter Journey") and "Die schöne Müllerin" ("The Miller’s beautiful daughter"). Both are about love affairs which end sadly.
Robert Schumann wrote many fine songs. He was a pianist before he became a composer, so it is not surprising that the piano parts of his songs are at least as important as the voice part. His song-cycle "Dichterliebe" ("Poet’s love") contains some of his best songs. They often have a dream-like atmosphere. He especially liked setting words by the poets Joseph von Eichendorff and Heinrich Heine.
Johannes Brahms always made the singer’s part more important than the piano part. He learned a lot by studying Schubert’s songs and wrote some very famous Lieder. One of his best is the humorous "Vergebliches Ständchen" ("Serenade in vain"). His "Four Serious Songs" are very powerful. His famous "Wiegenlied" ("Lullaby"), a tune which everybody knows, is one of his songs.
Hugo Wolf is known almost only for his songs. They are very dramatic and he used some unusual harmonies which he had learned by listening to Wagner’s music. Some of Wolf’s songs are very short, he says a lot in a short space of time. His "Italian song book" and "Spanish song book" have some of his best songs.
Richard Wagner and Gustav Mahler both wrote wonderful Lieder, although they are mostly with orchestral accompaniment. Mahler’s songs are inspired by folksong. He even uses them in his symphonies. "Das Lied von der Erde" is a song cycle for two singers (mezzo soprano and tenor) and orchestra.
Richard Strauss is one of the last great Lieder composers. His "Four last songs" (with orchestra) seem to be saying “goodbye” to a great period of music history.
Aurora
An aurora, also called polar light, northern light or southern light, is a natural light display in the sky. They are usually seen in the high latitudes (Arctic and Antarctic) regions. Auroras are produced when the Earth's magnetosphere is disturbed by the solar wind.
An aurora around the North Pole is called the "Aurora borealis" or 'northern lights'. Around the South Pole it is the "Aurora australis" or 'dawn of the south' or 'southern lights'. It can be seen from long distances, stretching in the sky many hundreds of miles far.
Auroras can happen at any time, however they can only be seen at night because their light is not as strong as the light of day. Faint stars can even be seen through the aurora.
Many legends are associated with the aurora in all countries where this phenomenon regularly occurs.
An aurora occurs when the Sun sends off small particles into space. These particles are mainly electrons, with charge and energy, which means they contribute to electricity. Earth has a protective shield of energy around it. This is called the "magnetic field" and forms an elongated sphere around the Earth called the "magnetosphere". The Earth’s magnetic field keeps off most of the solar wind.
At high-latitude areas (polar areas), the magnetic field is vertical. It does not keep off particles of the solar wind which can come from the magnetosphere and hit the particles of the air (Earth's atmosphere). When they hit, the atmosphere is heated and excited and the excess energy gets away, a phenomenon which we see as moving lights in the sky above 100 km altitude typically. An aurora can be especially bright following a solar flare and coronal mass ejection (CME), when the charged particles rip through the electromagnetic field because of their power.