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Answer the following questions:

  1. When and where was Ampère born?

  2. What sciences was he taught in his childhood?

  3. What position did he get in Lyon and later in Paris?

  4. What principles of electricity and magnetism did he demonstrate?

  5. What was Ampère's final work?

  6. Where is Ampère buried?

14. Daniel Gabriel Fahrenheit

Daniel Gabriel Fahrenheit was a German physicist and engineer who worked most of his life in the Dutch Republic. The Fahrenheit (°F) temperature scale is named after him. Fahrenheit was born in 1686 in Danzig (Gdańsk), in Royal Prussia, a province of Poland. The Fahrenheits were a merchant family who had moved to several cities. Daniel Gabriel was the eldest of the five Fahrenheit children (two sons, three daughters) who survived childhood. At age 16, Gabriel Daniel Fahrenheit began training as a merchant in Amsterdam after his parents died in 1702 from accidentally eating poisonous mushrooms. However, Fahrenheit's interest in natural science caused him to begin studies and experimentation in that field. From 1707, he traveled to Berlin, Halle, Leipzig, Dresden, Kopenhagen, and also to his hometown, where his brother still lived. In 1717, Fahrenheit mastered the trade of glassblowing, making barometers, altimeters, and thermometers. From 1718 onwards, he lectured in chemistry in Amsterdam. He visited England in 1724 and became a member of the Royal Society. Fahrenheit died in The Hague and was buried there at the Kloosterkerk (Cloister Church).

According to the one of Fahrenheit's article, he determined his scale by reference to three fixed points of temperature. The lowest temperature was achieved by preparing a mixture of ice, water, and ammonium chloride, a salt, and waiting for it to reach equilibrium. The alcohol or mercury thermometer was placed into the mixture and the liquid in the thermometer allowed descending to its lowest point. The reading on the thermometer was taken as 0 °F. The second reference point was selected as the reading of the thermometer when it was placed in still water as ice is just forming on the surface. This was taken as 32 °F. The third calibration point, taken as 96 °F, was selected as the thermometer's reading when the instrument was placed under the arm or in the mouth. Fahrenheit noted that mercury boils around 600 degrees on this temperature scale. Work by others showed that water boils about 180 degrees above its freezing point. The Fahrenheit scale later was redefined to make the freezing-to-boiling interval exactly 180 degrees. It is because of the scale's redefinition that normal body temperature today is taken as 98.6 degrees, whereas it was 96 degrees on Fahrenheit's original scale. Until the switch to the Celsius scale, the Fahrenheit one was widely used in Europe. It is still used for everyday temperature measurements by the general population in the United States and, less so, in the UK.

Answer the following questions:

  1. Who was Daniel Gabriel Fahrenheit?

  2. Which trade did Fahrenheit master in 1717?

  3. How does Fahrenheit’s temperature scale work?

  4. At what temperature does mercury boil?

  5. At what temperature does water boil?

  6. What is the normal body temperature by the Fahrenheit’s scale?

  7. Where is the Fahrenheit’s scale still used?

15. Ernest Rutherford

Ernest Rutherford was a New Zealand physicist who became known as the father of nuclear physics. He pioneered the orbital theory of the atom through his discovery of Rutherford scattering off the nucleus with his gold foil experiment. He was awarded the Nobel Prize in Chemistry in 1908.

Ernest Rutherford was the son of James Rutherford, who had emigrated from Perth, Scotland. Ernest was born at Spring Grove (now Brightwater), near Nelson, New Zealand. He studied at Havelock School and then Nelson College and won a scholarship to study at Canterbury College, University of New Zealand where he was president of the debating society, among other things. After gaining his BA, MA and BSc, and doing two years of research at the forefront of electrical technology, in 1895 Rutherford travelled to England for postgraduate study at the Cavendish Laboratory, University of Cambridge (1895–1898), and he briefly held the world record for the distance over which electromagnetic waves could be detected.

During the investigation of radioactivity he coined the terms alpha and beta to describe the two distinct types of radiation emitted by thorium and uranium. In 1898 Rutherford was appointed to the chair of physics at McGill University in Montreal, Canada, where he did the work that gained him the Nobel Prize in Chemistry in 1908. In 1900 he gained a DSc from the University of New Zealand, and from 1900 to 1903 he was joined at McGill by the young Frederick Soddy (Nobel Prize in Chemistry, 1921) and they collaborated on research into the transmutation of elements. Rutherford had demonstrated that radioactivity was the spontaneous disintegration of atoms. He noticed that a sample of radioactive material invariably took the same amount of time for half the sample to decay – its "half-life" – and created a practical application using this constant rate of decay as a clock, which could then be used to help determine the age of the Earth, which turned out to be much older than most of the scientists at the time believed.

In 1907 Rutherford took the chair of physics at the University of Manchester, where he carried out the experiment, which demonstrated the nuclear nature of atoms. It was his interpretation of this experiment that led him to the Rutherford model of the atom, with a very small positively-charged nucleus orbited by electrons. In 1921, while working with Niels Bohr, Rutherford theorized about the existence of neutrons, which could somehow compensate for the repelling effect of the positive charges of protons by causing an attractive nuclear force and thus keeping the nuclei from breaking apart. Rutherford's theory of neutrons was proved in 1932.

He died in 1937 and is interred in Westminster Abbey, near Sir Isaac Newton.

Answer the following questions:

  1. Who was Ernest Rutherford?

  2. What was his discovery in the orbital theory of the atom?

  3. Where did Rutherford study?

  4. What terms did he create to describe the two distinct types of radiation?

  5. On which research did they collaborate with Frederick Soddy?

  6. How did Rutherford offer to determine the age of the Earth?

  7. Where did he demonstrate the nuclear nature of atoms?

  8. What was the Rutherford’s model of atom?

16. James Watt

James Watt was born in 1736 in Greenock, a seaport on the Firth of Clyde. His father was a ship owner and contractor, while his mother, came from a distinguished family and was well educated. Both werePresbyterians and strong Covenanters. Watt attended school irregularly but instead he was mostly schooled at home by his mother. He exhibited great aptitude for mathematics, although Latin and Greek left him cold, and he absorbed the legends and lore of the Scottish people. When he was 18, his mother died and his father's health had begun to fail. Watt travelled to London to study instrument-making for a year, then returned to Scotland – to Glasgow – intent on setting up his own instrument-making business. By this time, he had studied the cylinder, using low pressure steam acting upon the vacuum in the lower part of the cylinder, which made use of atmospheric pressure. The next step was the development of a reciprocating motion, in which this process was reversed to create two power strokes. In 1776, the first engines were installed and working in commercial enterprises. These first engines were used for pumps and produced only reciprocating motion to move the pump rods at the bottom of the shaft. Orders began to pour in and for the next five years Watt was very busy installing more engines, mostly in Cornwall for pumping water out of mines. Over the next six years, he made a number of other improvements and modifications to the steam engine. He described methods for working the steam expansively. A compound engine, which connected two or more engines were described. Two more patents were granted for these in 1781 and 1782. In 1794 the partners Boulton and Watt established manufacture steam engines, and this became a large enterprise. By 1824 it had produced 1164 steam engines having a total nominal horsepower of about 26,000. Watt was an enthusiastic inventor, he continued to invent other things before and during his semi-retirement. He invented a new method of measuring distances by telescope, a device for copying letters, improvements in the oil lamp, a steam mangle and a machine for copying sculptures. He died on 25 August 1819 at his home in Handsworth, Birmingham, England at the age of 83.

The importance of the Watt's invention can hardly be overstated in the modern world. A key feature of it was that it brought the engine out of the remote coal fields into factories where many mechanics, engineers were exposed to its virtues and limitations. It was a platform for generations of inventors to improve. It was clear to many that higher pressures produced in improved boilers would produce engines having even higher efficiency, and would lead to the revolution in transportation that was soon embodied in the locomotive and steamboat. It made possible the construction of new factories that, since they were not dependent on water power, could work the year round, and could be placed almost anywhere. It made possible the cascade of new sorts of machine tools that could be used to produce better machines, including that most remarkable of all of them, the Watt steam engine. The unit of power incorporated in the International System of Units is named after James Watt.

Answer the following questions:

  1. Who was James Watt?

  2. What family did he come from?

  3. What did he study by the use of atmospheric pressure?

  4. What kind of engine did he invent?

  5. How many steam engines had he produced by 1824?

  6. What were other Watt’s inventions?

  7. Why can the importance of the Watt's invention hardly be overstated in the modern world?

  8. What unit in the International System of Units is named after James Watt?

17. Heinrich Hertz

Heinrich Rudolf Hertz was a German physicist who clarified and expanded the electromagnetic theory of light that had been put forth by Maxwell. He was the first to satisfactorily demonstrate the existence of electromagnetic waves by building an apparatus to produce and detect radio waves.

Hertz was born in Hamburg, Germany. While studying at the gymnasium of Hamburg, he showed an aptitude for sciences as well as languages, learning Arabic and Sanskrit. He studied sciences and engineering in the German cities of Dresden, Munich and Berlin. In 1880, Hertz obtained his PhD from the University of Berlin. In 1883, Hertz took a post as a lecturer in theoretical physics at the University of Kiel. In 1885, Hertz became a full professor at the University of Karlsruhe where he discovered electromagnetic waves.

Hertz always had a deep interest in meteorology, however, did not contribute much to the field himself except some early articles, including research on the evaporation of liquids, a new kind of hygrometer, and a graphical means of determining the properties of moist air when subjected to adiabatic changes. In 1881–1882, Hertz published two articles on what was to become known as the field of contact mechanics. Hertz is well known for his contributions to the field of electrodynamics however most papers that look into the fundamental nature of contact cite his two papers as a source for some important ideas. To develop his theory Hertz used his observation of elliptical Newton's rings formed upon placing a glass sphere. Hertz helped establish the photoelectric effect (which was later explained by Albert Einstein) when he noticed that a charged object loses its charge more readily when illuminated by ultraviolet light. In 1887, he made observations of the photoelectric effect and of the production and reception of electromagnetic (EM) waves, published in the journal Annalen der Physik. Earlier in 1886, Hertz developed the Hertz antenna receiver. This is a set of terminals that is not electrically grounded for its operation. He also developed a transmitting type of dipole antenna, which was a centre-fed driven element for transmission UHF radio waves. These antennas are the simplest practical antennas from a theoretical point of view. In 1887, Hertz experimented with radio waves in his laboratory. His experiments expanded the field of electromagnetic transmission and his apparatus was developed further by others in the history of radio. Hertz also found that radio waves could be transmitted through different types of materials, and were reflected by others, leading in the distant future to radar. He died at the age of 36 in Bonn, Germany in 1894, and was buried in Ohlsdorf, Hamburg at the Jewish cemetery. The unit hertz (Hz) was established in his honor by the IEC in 1930 for frequency, a measurement of the number of times that a repeated event occurs per unit of time.

Answer the following questions:

  1. Who was Heinrich Rudolf Hertz?

  2. In which disciplines was he interested while studying at the gymnasium of Hamburg?

  3. Which academic degrees did he obtain?

  4. Did he contribute much in meteorology?

  5. What phenomena did he study in the field of electrodynamics?

  6. What kind of device was the Hertz antenna receiver?

  7. What were his further experiments?

  8. What unit in the International System of Units is named after Hertz?