Determining what records have enduring value is not always easy. Archivists must also select records valuable enough to justify the costs of storage and preservation, plus the labor-intensive expenses of arrangement, description, and reference service. The theory and scholarly work underpinning archives practices is called archival science.
Roman Herzog
Roman Herzog (5 April 1934 – 10 January 2017) was a German politician (CDU). He was President of Germany from 1994 to 1999.
He studied law in Munich, Bavaria and took the first stage law exam in 1957. In 1958, he gained the title Dr.jur. (doctor of laws) and worked in the University of Munich until 1964, where he passed his second law exam. He wrote "Die Wesensmerkmale der Staatsorganisation in rechtlicher und entwicklungsgeschichtlicher Sicht" ("Characteristics of State Organization from a Juristic and Developmental-Historical Viewpoint"), and was given the title of professor in 1964.
In Germany "professor" is a title meaning senior teacher, not a job name. Herzog taught at the University of Munich until 1966. From 1966 he taught state law and political science as a full professor at the Free University of Berlin (FUB). In 1969 he moved to the FUB in Speyer, and was the University President from 1971 to 1972.
In 1973 he entered politics, and became a member of the Bundesrat for Rhineland-Palatinate. He was minister for culture and sports in the Baden-Württemberg Land Government from 1978. In 1980 he was elected to the State Parliament ("Landtag"), and took over the state Ministry of the Interior.
Herzog was also always active in the Protestant Church. Since 1982 he had been a member of the synod (parliament) of the Protestant Church of Germany. He had been a member of the Evangelical Church in Germany since 1972.
In 1983 he became vice president of the Federal Constitutional Court of Germany in Karlsruhe, and president over from 1987 to 1994, when he was elected President of Germany by the Bundesversammlung ("Federal Convention"). His term ended in 1999, when he was succeeded by Johannes Rau.
His wife, Christiane Herzog, died on 19 June 2000. He later married Alexandra Freifrau von Berlichingen in 2001.
Herzog died at 82 years old on 10 January 2017 in Jagsthausen, Germany.
Voltaic pile
The voltaic pile was the first ever battery. It was invented in 1800 by Alessandro Volta, an Italian physicist.
The picture to the right shows a voltaic pile: it's a pile, or "stack" of discs, made from 3 different materials. Some of the discs are made from copper, some from zinc. Other metals can be used; but it's important that there are two "different" kinds of metal. There are also discs made from leather, fabric, or cardboard: these are the green discs in the picture. They must be soaked, or "made wet", with something acidic.
Note how the discs follow a pattern: first a disc made from one of the metals, then a cardboard or leather disc, then a disc made from the other kind of metal. Then the same kinds of discs, in the same order, again and again. In the picture, you can see how one "set" of zinc disc, cardboard disc and copper disc has been "pushed" a little to the right. Such a "set" is called a "cell": the voltaic pile in the picture has 6 cells. The two different metal discs in a cell will each have a voltage across it; about 1.1 volts. Stacking cells in a pile adds to the voltage of the cells, and from the discs at the top and bottom of the voltaic pile in the picture, there is a voltage of 6 × 1.1 volts = 6.6 volts.
The acid in the leather, fabric, or cardboard discs will try to dissolve some of the metal in the zinc discs. To be dissolved, a zinc atom must give away 2 of its electrons. The zinc atom then becomes an ion: Ions can "go where they want to" in the liquid acid. They go through the leather/cardboard disc, and meet the copper disc. The zinc ions are "missing" the two electrons they left behind, so when they get to the copper disc, they each "steal" two electrons to replace the missing ones. When they "steal" electrons, the zinc ions turn back from ions to "normal" zinc atoms. Saltwater can also be used in the cardboard, fabric, or leather, in a voltaic pile using copper and zinc plates.
The result is that the zinc disc ends up with a lot of electrons "left behind" by the zinc ions, and the copper disc ends up "missing" a lot of electrons "stolen" by the zinc ions. To use the electricity that comes from the pile, we must connect something that uses electricity to the two discs at the top and bottom of the pile. Doing so gives the electrons left behind in the zinc disc a "chance" to go to the copper disc. At the copper disc, the electrons "replace" those that were "stolen" from the copper by the zinc.
Luigi Galvani was an Italian, working with anatomy. About 1786 he had seen something interesting: he had dissected (cut apart) a frog, and when he touched one of its legs with two tools made from different metals, it moved even though the frog had been killed before the dissection.
Galvani himself thought this had something to do with the leg, and not with the metal tools he used. Volta saw that the tools "must" be made from two "different" metals for the leg to move. Volta also found that he could make a little electricity just by making two different metals touch each other. He thought that the two different metals gave something he called "contact tension", and the electricity came from that contact tension. Galvani and Volta talked a lot about this, but they never agreed.
Volta tried to make use of it all. He made experiments with (and tried out) rods of different kinds of metals, in wine carafes (a kind of bottle). This way, he found that the best metals to use, are silver and zinc. He could also make it better by using flat discs instead of rods of metal. This is because the discs have more surface area than the rod; this gives more "room" for the zinc ions to leave one disc and get in touch with the other.
Originally, Volta put an extra disc of each metal at the top and bottom of the stack. These were later proved to be unnecessary.
Before the voltaic pile was invented, people could make only static electricity. With the voltaic pile, they could make electricity that keeps flowing for some time. Along with this, it was an invention that could be easily made. With this kind of electricity, scientists could do a lot of "new" things. For instance, when new kinds of metal were discovered, the electricity from a voltaic pile could "sort" chemicals. This way, small but very pure bits of these "new" metals could be made.
Arshile Gorky
Arshile Gorky (born Vostanik Adoyan; April 15, 1905 – July 21, 1948) was an Armenian-born American painter.
Gorky had a seminal influence on Abstract Expressionism and Surrealism. Gorky was born in the village of Khorgom, situated on the shores of Lake Van (Vana Lij). It is not known exactly when he was born: it was sometime between 1903 and 1905.In later years Arshile Gorky was vague about even the date of his birth, changing it from year to year. In 1910 his father emigrated to America to avoid the draft, leaving his family behind in the town of Van (Armenia).
Voltmeter
A voltmeter is an instrument used to measure voltage. For instance, a voltmeter can be used to see if there is more electricity left in a battery. The creation of voltmeters became possible when Hans Oersted invented the most simple voltmeter in 1819.
The voltmeter can be connected by joining two wires to where the voltage is. One wire is the positive one, and the other the negative. With some voltmeters, one "must" make sure that the wires are connected to the right spots: the positive connection on the voltmeter to the more positive "part" of the voltage source, and the negative to the more negative "part". This way, the voltmeter is parallel to the electrical circuit.