- •Авторы:
- •Введение
- •Alan Dower Blumlein (1903-1942): the Edison of electronics
- •Telephone engineering
- •Audio recording
- •Television
- •Blumlein's reputation
- •A. А. Campbell Swinton: master prophet of electronic television
- •Scottish descent
- •W. H. Eccles (1875–1966): the first physicist of wireless
- •Radio research
- •Bending round the Earth
- •Shakespeare
- •E. H. Colpitts: telephones, oscillators and the push-pull amplifier
- •Oscillator
- •Grace m. Hopper: originator of the first compiler and computer language to use English statements.
- •Irving Langmuir (1881-1957): World's Foremost Scientist
- •John Ambrose Fleming (1849-1945): The Birth of Electronics
- •Very happy thought
- •Nonagenarian
- •Karl Ferdinand Braun (1850-1918): Inventor of the oscilloscope
- •Rectification
- •Oscilloscope
- •Walter Schottky (1886-1976): Barriers, defects, emission, diodes and noise
- •Three-halves law
- •Schottky diode
- •Jack St Clair Kilby (born 1923): inventor of the integrated circuit
- •Pretty damn cumbersome.
- •A fireball
- •The pocket calculator
- •Russell and Sigurd Varian:
- •Childhood
- •Russell
- •The klystron
- •A hamburger celebration
- •Guglielmo Marconi (1874-1937): father of radio
- •Alexander Graham Bell (1847-1922): speech shaped current
- •Making sound visible
- •A little accident
- •Commercial success
- •Edwin Howard Armstrong (1890-1954): Genius of radio
- •Positive feedback
- •The superhet
- •Super – regeneration
- •Frequency modulation
- •Vladimir Kosma Zworykin (1889-1982): Catalyst of television
- •In Russia
- •Something more useful.
- •The storage principle
- •Later work
- •Joseph Henry (1797-1875): Actor turned engineer and scientist
- •Early days
- •Science and engineering
- •The first telegraph?
- •Princeton
- •Alan Mathison Turing (1912-1954): the solitary genius who wanted to build a brain.
- •Childhood
- •Computable numbers
- •Bletchley park
- •Almon Brown Strowger (1839-1902):
- •Inventor of the automatic telephone exchange
- •No need for girls
- •Trunk dialling
- •An ardent booster
- •Sir Charles Tilston Bright (1832-1888): The great feat of the century
- •To cross the Atlantic
- •The druggist's son
- •Patents
- •A first attempt
- •Another try
- •Into Parliament
- •Заключение
- •Библиографический список использованный
- •Оглавление
Computable numbers
Almost simultaneous with his election to a Fellowship was the publication of his first paper, a slight improvement on earlier work by the master mathematician John von Neumann. As it happened, von Neumann arrived in Cambridge shortly afterwards to spend the summer away from his home university of Princeton in America. Turing almost certainly attended his course of lectures; but his main problem now lay in choosing his field of research.
His interest in mathematical logic had been aroused by M.H.A. Newman's lectures in 1935. These included problems posed at the end of the 19th century by the German mathematician David Hilbert. One of these remained unsolved and in 1928 Hilbert himself proposed the Entscheidungs problem - "to find a method for deciding whether or not a given formula is a logical consequence of some other given formulae". (The mathematical details are discussed in references 1 and 2.)
Turing solved the remaining problem and went on to postulate a logical machine that could solve any problem of logic provided it was given a suitable set of instructions. This ran counter to the prevalent belief that different calculating machines were needed for different mathematical problems. Turing showed that it was possible logically, if not physically, to have one machine to do all. The concept was soon to be known as a "Turing machine". Within ten years such machines had, as Candy put it, "descended from the sky to the firm ground of information technology".
Turing's paper was called "On Computable Numbers, with an application to the Entscheidungsproblem" - Computable Numbers for short. Alan Turing had solved a major problem of mathematics with a fresh, direct and "simple" approach. Though it would take a little time to establish his reputation, that reputation was now assured.
He was not the only one to tackle the problem, however, for it had just been solved by an established American mathematician, Alonzo Church, at Princeton University. Though Turing's approach was radically different from Church's, the discovery of Church's work must have been a painful experience. Max Newman wrote to Church asking for help in getting Turing to Princeton so that he could be at the centre of things for a time and "so that he should not develop into a confirmed solitary". Alan Turing duly sailed for America on September 23,1936.
Princeton University had acquired the status of being the place for a mathematician to be. The Institute for Advanced Study had been set up there in 1932 and the double institute, as it could be viewed, attracted leading scientists to its bosom; Einstein was there, for example.
As with many great ideas when they are new, "Computable Numbers" did not cause a sensation though Church's review of it coined the expression "Turing machine". Turing described his work at a poorly-attended seminar and the paper was published whilst he was at Princeton. He was offered a second year in America, accepted, and submitted for a Ph.D. after a brief return to Cambridge.