The light is made by a small light bulb. In the 20th century, it was usually an incandescent bulb. Nowadays most use LEDs, which work slightly differently. In 1896, the first dry cell battery was invented. Unlike previous batteries, it used a paste electrolyte instead of a liquid. This was the first battery suitable for portable electrical devices, as it did not spill or break easily and worked in any orientation. Sometimes the electricity comes from a small generator instead of a battery.
The torch can also refer to a flammable stick that is lit on fire to provide light and (or) heat.
Hundreds of years ago, people used candles for all indoor light. This was expensive, and once the candle was gone, you would have to buy or make a new one or be stuck in the dark. When electricity was discovered and the light bulb was invented, David Misell, a British man working in Hubert's New York shop in 1898, came up with the idea of a light bulb that you could take with you, anywhere you wanted to go. Then, the torch was invented. The first flashlight has three D batteries which powered a small incandescent bulb. The bulbs would glow with a simple ON/OFF switch.
Discrimination
Discrimination is when someone is treated unfairly or differently. Discrimination is when a person is treated unfairly or badly because the person is one of a particular group. The Universal Declaration of Human Rights affirms that all persons must be protected against any kind of discrimination, or even its inciting.
A person might be discriminated against because of their race, age, sex, politics, sexual orientation, gender identity, religion, the way they look, a past criminal record, the person's lifestyle, their choice of clothing, their age or their disabilities whether they are a member of or fit in with a social clique (group), social class, social status or caste, and many other reasons.
Discrimination can take many forms. It can include being fired from a job, not being able to be hired for a job, being paid less money than others at the same job, being refused a home or apartment, teasing, harassment, or simply being treated differently than other people. Laws known as "equal opportunity legislation" protect people from discrimination. They say people should be employed whatever their race, age, sex or religion. There should be reasonable care for people with disabilities or accessibility. Two people in the same position must be paid the same wage if they have exactly the same job.
In some countries, discrimination against somebody on the basis of race, sex, religion, sexual orientation, age, or disability is illegal. Even in those countries where discrimination is unlawful, it still takes place for reasons not covered by the law. In some other countries, discrimination against somebody is legal or even official government policy. This especially takes place in countries in which there is an official religion, and people of other religions are discriminated against.
Ernest Rutherford
Ernest Rutherford, 1st Baron Rutherford of Nelson, OM, PC, FRS (30 August 1871 – 19 October 1937) was a New Zealand-born British scientist, who won the Nobel Prize in Chemistry in 1908, for his work on nuclear physics, and for the theory of the structure of the atom.
Rutherford was one of the first researchers in nuclear physics, after the discovery of radiation by the French physicist Henri Becquerel in 1896. Rutherford discovered the radioactive half-life, and the three parts of radiation which he named Alpha, Beta, and Gamma. He also discovered that alpha particles were the nuclei of Helium. Rutherford's Geiger–Marsden experiment led to what we know today about the atomic structure, where the atom is a nucleus and electrons orbit around it.
In 1919, Rutherford made the world's first artificial nuclear reaction, where he put alpha particles with nitrogen gas and created particles of oxygen isotopes and protons. This was nuclear transmutation, changing nitrogen gas into oxygen gas.
Rutherford was the leader of the Cavendish Laboratory in Cambridge. He proved the existence of the nucleus and that is was composed of protons and neutrons. In 1932 James Chadwick made an experiment at the Cavendish Lab that showed Rutherford was right.
Rutherford College, a school in Auckland, New Zealand, was named after him.
Serialism
Serialism is a way of composing music using a series of notes in a particular order and using this to build up a whole piece of music. These series and patterns can also be applied to other parts of music (like how loud or soft it is).
To show how serialism works we can take a very simple example. Let us use just five notes from the white notes of a keyboard. We can use the notes A, B, C, D and E. We are going to make a “tune” using all these five notes, but not repeating any until all five have been used (although we are allowed to repeat the note we have just had).
For example: we might have D, C, A, A, A, A, B, E. This is what we call our “row” or “series”, although usually one would expect a row of twelve different notes. It is the one we start off with, so we can call it our tone row.
We can change the tone row by playing it backwards. This is called retrograde. So we now get E, B, A, A, A, A, C, D.
We can also change it by playing it upside down. This means that instead of going up one step we go down one step, or instead of going up two steps we go down two steps etc. If we start on the same note D we now get: D, E, G, G, G, G, F, C. This is called inversion.
We can make it go backwards and upside down. So we get: C, F, G, G, G, G, E, D. This is called retrograde inversion.
We now have four ways of playing our row: tone row, retrograde, inversion, retrograde inversion.
These can now be transposed to create many more options.
In 1923 the composer Arnold Schoenberg (1874-1951) developed what he called the “twelve-tone system”. Instead of using just five notes as in our example, he used all 12 notes in the octave (5 black and 7 white notes on the piano keyboard). Most music we listen to is in a particular key (tonality). This is called “tonal” music. For example: if we start “Twinkle, twinkle little star” on a C we finish on a C at the end and the piece sounds finished. It is “tonal” (in a particular key). In twelve-tone music all 12 notes are equal, there is no “key note” (it is “atonal”). This makes the music very hard to understand and it took people a long time to get used to the sound of Schoenberg’s new music.
Schoenberg was not the only composer to use this way of composing. His pupils Alban Berg (1885-1935) and Anton Webern (1883-1945) also wrote twelve-tone music. Schoenberg, Webern & Berg are sometimes called the "Second Viennese School"-The first was Haydn, Mozart and Beethoven a hundred years before. The composers Igor Stravinsky (1882-1971) and Aaron Copland (1900-1990) started to write twelve-tone music when they were quite old. Composers such as Benjamin Britten (1913-1976) used it occasionally, often putting it together with music which was tonal (listen to Britten’s opera “Midsummer Night’s Dream”). When contrasted with tonal music in this way it can be very beautiful.
In the 1950s and 1960s some composers like Pierre Boulez (b.1925) and Karlheinz Stockhausen (b.1928) wrote music which was not only twelve-tone, but serial in other ways as well. For example: they organized levels of dynamics (from very quiet to very loud) in a series, and the lengths of notes (from very short to very long), and even timbre (the sound quality). By combining all these things their music became very complicated indeed. When all these things were used for the whole piece of music it was called “total serialism”. Boulez’s "Structures I" is an example of a piece which uses “total serialism”. A lot of people criticized this music, saying that it was too mathematical instead of being expressive. Such music can be hard to understand.
Frédéric Chopin