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Файл:Великие ученые и изобретатели = Great Scientists and Inventors. Учебное пособие
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Text
It is well known that Volta invented the primary battery and in so doing
moved electrical science into an age of electrodynamics. What is less known is
that he proposed a fundamental unit of electric tension some years before that
invention, when scientists were still deep in the age of electrostatics. It is perfectly appropriate then that the unit for electro – motive force (a term he introduced) is named after him. We may be thankful, though, that is original unit
was never accepted; it is roughly equal to 13 350 volts!
Volta was already an established scientist with a reputation for experi-
mental work when he announced the invention of the “Pile”, the first electric
battery. The importance of the invention was instantly recognized as being of
the first rank and in opened new avenues of enquiry, including electrochemistry
and electrodynamics. It quickly led to experimental electric light and industrial
electroplating.
Volta was born in Como in the duchy of Milan in Northern Italy on the
18th February 1745 and died there 82 years later on the 5th March 1827. On his
mother’s side he came from a family with a leaning towards the law; his fa-
ther’s family was devoted to the church.
He was seven when his father died. When he was 12 one of his uncles took
charge of his education, which began at a Jesuit college and nearly led to him
becoming a Jesuit. His uncles decided they did not want that and so his education continued elsewhere. It was a wealthy friend, Giulio Cesare Gattoni, who
provided the books and equipment which helped him to begin studying electricity.
The uncles had by now chosen his future career: the law. Somehow he
avoided this path and continued to study what he termed his genius: electricity.
Slowly, from the mid 1760’s he learned the science and practice of electricity and in October 1774 he received his first academic appointment, at the
Gymnasium in Como. The next year he was appointed professor of experimental physics. About the same time he made his first important invention, the
electrophorus, and followed that with the discovery of methane.
The electrophore was probably the most significant electrical invention
since the Leyden Jar capacitor. After considerable experimentation, in June
1775, he announced his “elettroforo perpetuo”. It was an inductive device for
repeatedly charging a tin foil covered shield which, in turn, was used to build
up a large charge on the Leyden Jar capacitor.
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In 1776, he briefly turned to the study of gases and discovered a new gas
which we know as methane. “Inflammable air” (hydrogen) had been isolated
chemically ten years earlier and was known to exist naturally. Volta became intrigued by the “different kinds of air” and searched the countryside for the telltale bubbles until he found a new gas at Lake Maggiore. Hydrogen, however,
was more explosive and it was hydrogen and air (oxygen), not methane, that
Volta used in an “inflammable air pistol” which was fired by an electric spark.
The pistol fired a led ball, denting wood at 15 feet. From related experiments he
concluded that about 20% of common air was oxygen. He narrowly missed synthesizing water, but his method was successfully used later by Lavoisier, Laplace and Monge in France
His discovery of methane obviously enhanced his scientific reputation and
his reward was a travel grant, which took him to Switzerland and Alsace. The
grant came from the Austrian government which then ruled Northern Italy.
Then came Volta’s appointment to professorship of experimental physics at the
University of Pavia; his popular professorship there ran for nearly 40 years.
The primary battery was by then well-known and its chemical power had
made scientific headlines. Even Napoleon attended his demonstrations at the
French Academy and Volta was awarded a gold medal.
In many ways Volta’s discoveries captured Napoleon’s heart and he continued to be an admirer. A prize of 60,000 francs was announced for “whoever
by his experiments and discoveries makes a contribution to electricity and galvanism comparable to Franklin’s and Volta’s”. Volta was later given a pension,
and made a count and a senator in the kingdom of Italy.
The roots of Volta’s invention go back to the discovery by his fellow Italian, Luigi Galvani, of frog legs fame. A full account was published in 1791 and
caused great excitement amongst both physicists and the medical fraternity. The
latter wondered if the “vital principle” had at last been found and pondered the
possibilities for new treatments. Galvani was the second to report what we
would now recognize as an electrochemical effect, the Swiss J. G. Sulzer having noted in 1762 that two dissimilar metals placed on the tongue gave a sensation of taste.
At first, Volta dismissed Galvani’s reports as unbelievable. Pressed by colleagues, he at last investigated the phenomenon and, by the April 1 1791, had
begun the series of careful step by step experiments which led him to the electric battery.
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Galvani explained the excitation of the dead frog’s legs as being caused by
animal electricity, an explanation which Volta firmly rejected. Volta was led to
believe that the current flow was caused by the contact of two different metals.
In that he too was wrong. It was another Italian, G.V. Fabroni, who got the right
explanation by pointing to a chemical action between the liquid, which always
seemed to be present in both Galvani’s and Volta’s work, and the two different
metals.
Volta repeated Sulzer’s as well as Galvani’s work. In one experiment he
brought insulated zinc and copper disks into contact and found that they were
charged on separation. By experiment he found that zinc and silver disks best
suited his purpose and eventually he arranged pairs of them in a pile. Each pair
was separated from neighbouring pairs by a piece of cardboard soaked in water
or brine to provide, as he believed, a conducting path between the pairs. Letting
all pairs touch one another, he knew, provided only the same effect as a single
pair of discs.
The finished pile of discs and cardboard multiplied the effects of a single
pair many times and he was able to receive a shock from his pile similar to that
from a charged Leyden Jar capacitor. The vital differences were that Volta’s
pile did not need to be immediately recharged and could give a continuous current.
Volta received many honours in his lifetime, including recognition by
learned societies in London, Paris and Berlin. His financial rewards from his
university salary were boosted in 1805 by the annuity he received from Napoleon and, in 1809, by his senatorial salary. For the last two decades of his life “he
had “the income of a wealthy man”.
2. Просмотрите текст. Найдите ответы на следующие вопросы:
1. What unit was named after Volta?
2. Why is the invention of the first electric battery important?
3. When and where was Volta born?
4. How did he begin studying electricity?
5. When did he receive his first academic appointment?
6. What was his first important invention?
7. What gas did he discover?
8. What was the reward for his discovery of methane?
9. Where do the roots of Volta’s invention go back to?
10. What honours and rewards did he receive in his lifetime?
13
3. Просмотрите текст. Укажите, являются ли предложения вер-
ными или неверными. Докажите, используя информацию из текста.
1. Volta proposed a fundamental unit of electric tension.
2. The unit for electro-motive force is named after Volta.
3. Volta’s original unit was accepted.
4. The importance of the invention of the “Pile” was not recognized.
5. Methane had been isolated chemically ten years earlier than hydrogen.
6. Methane was known to exist naturally.
7. Volta’s professorship at the University of Pavia ran for nearly 40 years.
8. Even Napoleon attended his demonstrations of the primary battery at the
French Academy.
9. Volta was awarded a gold medal for his invention of the primary battery.
10. Galvani explained the excitation of the dead frog’s legs as being caused
by the contact of two different metals.
4. Выполните следующие грамматические задания:
1. Найдите в тексте предложения с эмфатической (усилительной) кон-
струкцией и переведите их на русский язык.
2. Найдите в тексте предложения с инфинитивными оборотами и пе-
реведите их.
3. Найдите в тексте предложение с причастием в форме Continuous
Passive и переведите на русский язык.
4. Найдите в тексте инфинитив в функции определения и переведите
на русский язык.
5. Найдите в тексте предложение с герундием в функции части гла-
гольного составного сказуемого и переведите на русский язык.
6. Найдите в тексте предложение с причастием в форме Perfect Active,
укажите функцию и переведите на русский язык.
5. Используйте следующие темы для обсуждения в виде диалогов
или монологов:
1. Alessandro Volta, interpreter and emulator of Nature.
2. Volta’s discovery of methane.
14
3. The electrophore was probably the most significant electrical invention
UNIT III
WALTER SCHOTTKY
(1886–1976)
since the Leyden Jar capacitor.
4. Volta’s Pile.
5. Volta’s discoveries captured Napoleon’s heart.
It is interesting to know:
1. It is well known that Volta invented the primary battery.
2. Volta moved electrical science into the age of electrodynamics.
3. The volt was formally proposed as a unit of EMF in 1863 by a committee of the British Association for the Advancement of Science, although it may
already have acquired some usage amongst practical telegraph engineers. It was
adopted internationally in 1881.
1. Прочитайте английские слова и назовите их русские эквиваленты. Просмотрите текст. Выполните упражнения после текста.
1) accolade
2) thermionic emission
3) semiconductor
4) thermionic valve electronics
5) solid-state electronics
6) contribution
7) physicist
8) solid body
9) black-body radiation
15
10) achievement
11) amplification
12) electronic valve
13) amplifier
14) electronic circuitry
15) valve amplifier
16) result from
17) occur
18) charge
19) appear
20) suggest
21) junction
22) rectifier
23) p-n junction
24) anticipate
Text
In the parlance of electronics engineers, “Schottky” has passed from being
a man’s name into being a technical term in a very wide use. That is not a
unique honour but it is perhaps an accolade which stands above medals, awards
and citations from learned societies, prestigious as such things are. Walter
Schottky’s name is associated with thermionic emission, noise, defects in semiconductors and the Schottky diode. It is perhaps best known now in the context
of Schottky TTL (Transistor-Transistor Logic), so named because of the modification of standard TTL by the addition of a metal-semiconductor or Schottky
diode.
Schottky career spanned the ages of both thermionic valve electronics and
solid-state electronics, and he made major contributions to both. He worked in
both industrial and university research laboratories, and was known as modest
and selfless character who avoided the centre stage.
He was born on July 23, 1886 in Zurich, Switzerland, but he spent his life
in Germany. He died on March 4, 1976 in his 90th year, at Pretzfeld (near Erlangen), the town to which he had retired in 1958. His death came just two
years after his old employer, Siemens, had begun commercial manufacture of
Schottky diodes for microwave use.
16
Schottky’s father, Friedrich, was a university mathematition. As a result of
his career move from Marburg to Berlin, Schottky attended schools in both
places and entered the Humboldt University in Berlin in 1904, where he studied
physics. In 1912, he was awarded a doctorate in Berlin for his thesis on the
Special Theory of Relativity which Einstein had announced only seven years
earlier. Schottky’s tutor was Max Planck, the originator of the Quantum theory
and a man at the heart of much of modern physics. Schottky could hardly have
wished for a better start to a career as a physicist.
After receiving his Ph. D., Schottky went to Jena, some 45 miles southwest of Leipzig, where he worked under Max Wien. It was here that he turned
away from relativity theory and turned to what was to become his life’s work –
the interaction of electrons and ions in vacuum and solid bodies. To put it another way: electron physics.
For the next 15 years his career pattern was to be one of movement between university and industrial research. Finally he settled for industrial research with Siemens A G.
The pattern began with a couple of years with Max Wien at Jena, after
which he joined the Siemens industrial research laboratories in Berlin, staying
there until 1919. In 1920 he returned to university life, this time under Wilhelm
Wien at Wurzburg. It was there that he qualified as a university lecturer. W.
Wien is chiefly remembered for his work on black-body radiation, for which he
received the Nobel Prize in Physics in 1911. After three years with Wien,
Schottky advanced his academic career, becoming Professor of Theoretical
Physics at Rostock. He was then in his late thirties. Finally in 1927, at the age
of 40 or 41, he moved for the last time, back into industrial research, rejoining
Siemens A G. He stayed there until his retirement.
Schottky’s achievements can be loosely divided into two phases: the first
being research into vacuum electronics and the second, starting in 1929, covering semiconductor electronics. Of course, there side issues to these two generalizations, some of which would alone have guaranteed him a place in the history
books. The invention of the ribbon microphone was one, the superhet another.
The ribbon microphone dates from 1924 and was invented jointly with Erwin Gerlach. They used an extremely thin concertina ribbon of aluminium
placed between the poles of a permanent magnet. Reversing the physical effects
led them to invent a ribbon loudspeaker as well, also using a thin ribbon of al-
17
luminium. The invention of the superhet is usually credited to the American
Edwin Armstrong, but Schottky independently discovered the same principle of
the superheterodyne with IF amplification in 1918. Coming second, it would
seem, does not provide lasting fame, except perhaps in one’s home country. At
Jena, where Schottky began his work on electron physics, he performed both
theoretical and experimental studies of the space charge effects of electrons
emitted from cathodes in vacuum tubes. In 1913/14, at about the same time a
Irving Langmuir in America, he independently discovered the basic law relating
the current in a valve to the applied voltage; the V3/2 law. Here, at least, he
gained more lasting fame than with the superhet; it was a pioneering achievement and would have established him as a leading physicist. It may also have
helped to determine his temporary career move to Siemens in 1915.
At Siemens, Schottky further developed his interests in electronic valves.
Though he was there only from 1915 to 1919, he seemed reel off a series of
discoveries or inventions. His invention of the screen-grid valve or tetrode
(which apparently he originally called the protection grid tube) was a major invention in electronics yet, in the light of hindsight, it was possibly overshadowed by his prediction of thermal and shot noise, two of the fundamental classes of noise in electronic devices.
The Schottky diode is made from a junction between a metal and a semiconductor instead of a junction between two pieces of semiconductor. Schottky
published his diffusion theory of current transport in metal-semiconductor junctions. It was from this theory that modern understanding grew, hence a metalsemiconductor diode is usually known as Schottky diode.
2. Просмотрите текст. Найдите ответы на следующие вопросы:
1. What fields of science did Schottky make contribution to?
2. When and where was he born?
3. What was his thesis about?
4. What science did Schottky turn to?
5. What is Wilhelm Wien famous for?
6. What phases can Schottky’s achievements be divided into?
7. What studies did he perform working on electron physics?
18
8. What was Schottky’s pioneering achievement?
9. What interests did Schottky further develop at Siemens?
10. How many sources of noise of a fundamental nature would there be in
an amplifire?
3. Просмотрите текст. Укажите, являются ли предложения вер-
ными или неверными. Докажите, используя информацию из текста.
1. Schottky’s name is associated with thermionic emission, noise, defects
in semiconductors and the Schottky diode.
2. Schottky’s career spanned the ages of both thermionic valve electronics
and solid-state electronics.
3. W. Wien is chiefly remembered for his work on solid-body, for which
he received the Nobel Prize in physics in 1911.
4. After three years with Wien, Schottky advanced his academic career,
becoming Professor of Applied Physics at Rostock.
5. Schottky’s achievements can be divided into two phases, the first being
research into solid- state electronics and the second starting in 1929, covering
thermionic valve electronics.
6. Schottky invented the ribbon microphone and the superhet.
7. The ribbon microphone was invented jointly with Erwin Gerlach.
8. The classic paper on noise in tetrode was published by Walter Schottky
in 1918 in Germany.
9. Schottky had reached the conclusion that there would be two sources of
noise of a fundamental nature in a thermionic valve.
10. The Schottky diode is made from a junction between two pieces of
semiconductor.
4. Определите грамматические явления в предложениях и объясните их.
1. After receiving his Ph. D., Schottky went to Jena, some 45 miles southwest of Leipzig, where he worked under Max Wien.
2. It was here that he turned away from relativity theory and turned to what
was to become his life’s work- the interaction of electrons and ions in vacuum
and solid bodies.
19
3. For the next 15 years his career pattern was to be one of movement be-
tween university and industrial research.
4. It was there that he qualified as a university lecturer.
5. Schottky’s achievements can be divided into two phases, the first being
research into solid state electronics and the second starting in 1929, covering
thermionic valve electronics.
6. Reversing the physical effects led them to invent a ribbon loudspeaker
as well, also using a ribbon of aluminum.
7. Though he was there only from 1915 to 1919, he seemed to reel off a series of discoveries or inventions.
8. It was from this theory that modern understanding grew, hence a metalsemiconductor diode is usually known as a Schottky diode.
5. Используйте следующие темы для обсуждения в виде диалогов
или монологов:
1. Walter Schottky’s name is associated with thermionic emission, noise,
defects in semiconductors and the Schottky’s diode.
2. Schottky’s career spanned the ages of both thermionic valve electronics
and solid state electronics.
3. The invention of the ribbon microphone and the superhet.
4. Schottky’s work on electron physics.
5. Schottky diode.
It is interesting to know:
1. In the parlance of electronics engineers, “Schottky” has passed from be-
ing a man’s name into being a technical term in a very wide use.
2. Walter Schottky’s name is associated with thermionic emission, noise,
defects in semiconductors and the Schottky’s diode.
3. Schottky’s name is perhaps best known now in the context of Schottky
TTL (Transistor-Transistor Logic), so named because of the modification of
standard TTL by the addition of a metal-semiconductor or Schottky diode.
4. Schottky’s career spanned the ages of both thermionic valve electronics
and solid-state electronics.
20
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