A Thumbnail History of Electronics
I. Cathode Rays & the Discovery of the Electron
Although many of the pioneers of 19th Century physics, including Faraday, were convinced on the basis of
chemistry and the phenomena observed in electrolysis that electric current consisted of the flow of particles of
charge, the nature of these charges was not understood. Even the basic question of whether the charge of the
particles was positive or negative remained undetermined. The answers to these questions, and to the basic
structure of matter, were resolved by experiments that began with the study of electric discharges in evacuated
tubes. Along the way a series of discoveries were made which led to the technological revolution of the 20th
Century.
-------------------------------------------------------------------------------William Crookes (1832-1919), heir at an early age to a large fortune, carried out his investigations in a private
laboratory. His studies of electrical discharges in gases, which followed the development of the cathode ray
tube by Pluecker and Hittorf, and his observations of cathode rays and the dark space at the cathode led to the
discovery of x-rays and of the electron. Crookes also invented the radiometer, whose eventual explication
verified the kinetic theory of gases. Curiously, Crookes was a believer in the occult and in the 1870’s claimed
to have verified the authenticity of psychic phenomena. Later he became involved in the Theosophical
Movement and there are references to his having exorcised demons. In 1897 Crookes was knighted by Queen
Victoria (who is also reputed to have had an interest in the occult) and in 1909 was elected president of the
Royal Society.
Karl Ferdinand Braun (1850-1918) was director of the Physical Institute and a professor of Physics at the
University of Strasbourg when he demonstrated the first cathode ray tube oscillograph, guiding a narrow
stream of electrons to a fluorescent screen and presaging the modern television screen. Although little
remembered today, Braun made several important contributions. He discovered that rectification occurs at a
crystal/metal junction, leading to the introduction of crystal receivers. In 1899, he introduced (sparkless)
inductive coupling to antennas and the first directive beam antenna. He received the Nobel Prize in 1909
along with Guglielmo Marconi. Braun was in New York to testify in a patent suit when the United States
entered World War I; he was interned as an enemy alien and died before the war ended.
Wilhelm Conrad Roentgen (1845 -1923) was 44 years old, head of the Physical Institute and recently retired
Rector (President) of the University of Wurzburg when, in November, 1895, he discovered that some
unknown radiation coming from a Crookes tube could cause crystals to fluoresce, pass through solid objects,
and affect photographic plates. Working alone, sometimes sleeping in his laboratory, and maintaining great
secrecy, he completed his research and eight weeks later announced his discovery. The scientific and medical
implications of his work were immediately recognized and reported world-wide following its publication on
New Year’s Day in 1896. Within a few weeks some hospitals began to use x-rays. Roentgen became one of
the most renowned scientists in the world. He received many honors, including the first Nobel prize in
Physics and an offer (refused) to be raised to the nobility.
J(oseph) J(ohn) Thomson (1856-1940), the son of a Manchester bookseller, entered college at fourteen and at
twenty-eight was elected a fellow of the Royal Society and appointed to the Chair of Physics at the Cavendish
Laboratory. His great discovery occurred in 1897 during the course of his investigations of cathode rays.
Thomson provided convincing evidence that the rays consisted of charged particles; he measured the ratio of
charge to mass and was able to estimate that the mass was equal to about 1/1800 of the mass of a hydrogen
atom. His discovery of the electron won the Nobel Prize in 1906 and he was knighted two years later.
Thomson was described by Rutherford as having "a most radiating smile, … when he is scoring off anyone."
Robert A. Millikan (1868 -1953) began his career as a classics major at Oberlin College, but agreed to teach
Physics in order to earn more money. When he was offered a fellowship in Physics at Columbia he accepted,
but again only because it was the best offer he could get financially. His academic career at the University of
Chicago was at first devoted to teaching and administration and he did not begin to do research seriously until
he was almost forty. Then, in 1906 he began to devise a series of improvements to the Thomson experiment
that led to the oil-drop apparatus in which the charge of the electron was measured conclusively. His results
were published in 1910 and the last resistance to the atomic theory of matter was dispelled. In 1914 he
published the results of the research for which he was awarded the Nobel Prize - the direct determination of
Plank’s constant using the photoelectric effect - verifying the 1905 Einstein theory of the photoelectric effect
and the quantum nature of light.
II. Wireless Telegraphy
Maxwell's 1865 publication of a theory which unified electrodynamics, magnetodynamics, and optics had
seemingly little impact in Britain where it was not widely accepted. Surprisingly, during the remaining
fourteen years of his life, Maxwell, who was a skillful experimentalist, did not attempt to verify the existence
of the electromagnetic waves that his theory predicted. However, the leading German scientist of the period,
von Helmholtz, believed the Maxwell theory and he set his pupil Hertz on the track of producing and
detecting electromagnetic radiation, opening the path to wireless communication.
--------------------------------------------------------------------------------
Heinrich Rudolf Hertz (1857-1894), a professor of physics at Karlsruhe Polytechnic, was the first to broadcast
and receive radio waves in the laboratory. Between 1885 and 1889, he used spark discharges to produce
electromagnetic waves. Hertz's radiator consisted of a pair of aligned rods, with a spark gap between them
and capacitative plates at their ends. His receiver was a loop of wire with a small gap across which a small
spark could be observed when the radiator discharged. Herz died suddenly of a brain tumor when he was
thirty six, perhaps never realizing that transmission and reception over long distances was possible.
Edouard Eugène Désiré Branly (1844-1940) is revered in France as the inventor of wireless telegraphy. In
1890, Branly, a professor of Physics at the Catholic University of Paris, discovered that when exposed to even
a distant spark transmission field, loose zinc and silver filings would cohere and provide a path of increased
conductivity that could be used to detect the presence of the transmission. The "coherer" took radio
transmission out of the laboratory and made communication over long distances possible.
Oliver Joseph Lodge (1851-1940) held the chair in Physics at the University College in Liverpool when he
demonstrated a practical form of the Branly coherer in 1894. Lodge added a device that shook the filings
loose between spark receptions. It became a standard device in early wireless telegraphy. Lodge also
obtained the first patents for the use of tuned circuits to adjust the frequency of receivers and transmitters.
After 1900, however, Lodge devoted himself to psychic research and attempts to communicate with the dead.
In 1902 he was appointed the first principal of the new Birmingham University.
Guglielmo Marconi (1874-1937) failed the entrance exams to the Italian Naval Academy and the University
of Bologna but was allowed by a family friend to attend lectures and laboratory at the university. In 1896, at
age twenty-two, he patented a successful system of radio telegraphy . In the following years he introduced a
notable series of inventions and ingenious redesigns of transmitting and receiving system components. In
1901 Marconi succeeded in receiving signals transmitted across the Atlantic Ocean. It may be fairly said that
Marconi single-handedly advanced the development of radio telegraphy by decades. Marconi's Wireless
Telegraphy Company soon established a net of coast stations in Britain for ship-to-shore communication.
These were taken over by the British General Post Office in 1910, but for more than a decade the Marconi
Company enjoyed a monopoly on maritime radio equipment sales by virtue of an agreement with Lloyds of
London to only insure ships that used their equipment. In 1909 Marconi received the Nobel Prize for
Physics.
III. VacuumTubes
The Edison effect, the appearance of an electric current flowing between a heated cathode and an anode in an
evacuated tube, was a mysterious phenomenon when it was discovered in 1882; it was not understood how
electric current could pass through a vacuum. Thomson's identification of cathode rays as streams of electrons
resolved the mystery and led to the invention of the thermionic diode by Fleming. The diode, intended to
serve as a rectifier to detect radiotelegraphic signals, had little impact as the coherer, invented by Branly and
Lodge, and crystal and magnetic detectors continued to be used. The invention of the triode by DeForest,
however, did revolutionize radio communication.
--------------------------------------------------------------------------------
Thomas Alva Edison (1847-1931) was owner or co-owner of a record 1,093 patents. He also invented the
modern industrial research laboratory. In 1882, when one of his engineers, William Hammer, observed the
"Edison Effect" during the course of experiments about the incandescent lamp, Edison, for reasons which he
could not later explain, uncharacteristically did not follow up on the discovery. But, as he later admitted, at
the time he did not even understand Ohm's law. The Edison effect remained an unexplained curiosity for
fifteen years until the discovery of the electron.
John Ambrose Fleming (1849-1945) had a remarkable career which spanned the first seventy-five years of the
development of electronics. Fleming was a student of Maxwell’s who later worked as a consultant for Edison
and then Marconi. In 1904, following Edison’s observation of the passage of current from the filament to an
anode in a light bulb and J.J. Thomson’s discovery that cathode rays consisted of charged particles, Fleming
invented and patented the first electronic rectifier, the diode, or Fleming Valve. The device was intended for
use in detecting the spark-generated radio waves of the time, replacing the other devices used by the pioneers
of radio communication. Fleming was knighted in 1929.
Lee De Forest(1873-1961), son of a Congregational minister who was president of the Talledega College for
Negroes in Alabama, lived a long life full of controversy. He was defrauded by partners, was involved in
numerous patent suits, went through two divorces, and once was indicted (but later acquitted) for mail fraud
for seeking to sell a worthless device (his audion tube), De Forest held more than 300 patents but is most
remembered for initiating the electronic revolution with his 1906 invention of the audion tube, a threeelement vacuum tube in which the grid controlled the current, which made modern radio possible. In 1912 he
conceived the idea of cascading triodes to achieve high amplification and also independently discovered
regenerative feedback.
William D. Coolidge (1873-1975), an electrical engineering graduate of MIT and the University of Leipzig,
joined the General Electric Research Lab after a brief career in Academia. In 1911, he succeeded in
fabricating a ductile form of tungsten which provided the filaments for modern incandescent lamps and also
patented a thoriated cathode with improved emission for use in vacuum tubes. In 1913 Coolidge invented a
hot-tungsten filament x-ray tube which provided a more penetrating and reliable source for radiology. The
"Coolidge tube" became the standard generator of medical x-rays.
Walter Schottky (1886-1976) discovered the random noise due to the irregular arrival of electrons at the
anode of thermionic tubes that is called "shot noise" (Schottky effect) in 1914 while studying under Planck in
Berlin. Schottky was Swiss, but he was educated and spent his professional career in Germany. In 1919 he
invented the first multiple grid vacuum tube, the tetrode. Schottky obtained multiple doctoral degrees, taught
at universities from 1920 to 1927, and then worked for Siemans for nearly five decades. He was the first to
note the existence of "holes" in the band structure of semiconductors, discovered the type of lattice vacancy
known as the Schottky defect, and in 1938 created a theory that explained rectification at a
metal/semiconductor interface.
Irving Langmuir (1881-1957), son of a struggling Brooklyn businessman, showed a precocious interest in
Science. He received his degrees in Chemistry, but, tiring of the endless round teaching elementary courses
and paper grading required of professors, left academia and went to the General Electric Research Laboratory.
His work on molecular films won the Nobel Prize in Chemistry in 1932, and his studies on hot filaments in
gases became the basis for improvements in incandescent lighting and a huge industry. His discoveries about
the emission of electrons from cathodes and their behavior in vacuum tubes formed the basis for the design of
a variety of tube types.
IV. Radio
Speech transmission using a spark transmitter was demonstrated by Fessenden in 1900 but was too noisy; in
1906 he broadcast the first program of speech and music using 50 KHz generated by an alternator. Fessenden
also discovered the heterodyne principle of mixing a low frequency signal with the high frequency carrier.
The 1913 discovery by De Forest and Armstrong of regenerative feedback and how to use the triode as an
oscillator made commercial radio possible. Armstrong’s invention of the superheterodyne receiver in 1917
and FM in 1933 brought radio into the modern era. However, the technical triumphs were marred by years of
bitter patent suits between all the participants and led to great personal tragedies.
-------------------------------------------------------------------------------Reginald Aubrey Fessenden (1866-1932) was a Canadian-American who first worked for Edison. In 1900,
while working for the U.S. Weather Bureau, he developed the ideas of continuous wave transmission and
amplitude modulation and the heterodyne principle to permit speech transmission. After 1902, he directed the
development of a one kilowatt, 50 kHz alternator to replace the spark transmitter, and invented an electrolytic
detector for continuous waves. In December 1906 he realized the first radio-telephonic broadcast. Fessenden
held hundreds of radio patents and also invented a variety of devices which included the radio compass and
the fathometer. He was described as "a stormy and colorful figure" and for years he was deeply involved in a
series of litigations against his patents.
Edwin Howard Armstrong (1890-1954) was a junior engineering student at Columbia in 1912 when he
invented regenerative feedback and electronic oscillators. Although a later corporate suit brought by De
Forest, led to the courts decision in favor of De Forest, the engineering community has continued to regard
Armstrong as the inventor. Then in 1917 while serving in the army, Armstrong invented the superheterodyne
receiver which is the basis for virtually all modern radio and radar communication systems. This patent was
not disputed and Armstrong became a millionaire. Armstrong’s third invention was the superregenerative
detector. Then, in 1933 Armstrong obtained a series of patents covering his invention of (wideband) FM, a
new system of radio communication. The radio industry, with a vested interest in AM, had no interest in FM
and Armstrong had to build the first station himself. FM slowly gained acceptance, but Armstrong,
impoverished and embroiled in more patent suits, committed suicide.
Louis Alan Hazeltine (1886-1964) became head of the Electrical Engineering Department at Stevens Institute
of Technology in 1917; this was the department which had awarded him his bachelor’s degree only eleven
years before. During World War I, he designed a radio receiver for the U.S. Navy. In 1922, Hazeltine
invented the "neutrodyne" receiver to eliminate the squeaks and howls of the early radio receivers. The
Hazeltine amplifier neutralized the grid-to-plate capacitative coupling which was a cause of oscillation in
triode amplifiers. The neutrodyne was the first commercial receiver suited to general public broadcast
reception. By 1927 some ten million of these receivers were being used by listeners in the U.S.
Harold Stephen Black (1898-1983) worked, after graduation from Worcester Polytechnic, for a department of
Western Electric Company which later became Bell Telephone Laboraotories. For six years he pursued a
seemingly futile project to improve the distortion characteristics of amplifiers. In a storied incident, the
answer was conceived in a creative flash during a commuter ride on a ferry in 1927. He wrote the equations
on a blank page in his daily newspaper. Although at first it seemed paradoxical, negative feedback effected an
extraordinary performance in amplifier performance.
V. Television
The pioneers of television were the Russians, Nipkow who invented a mechanical revolving scanning disk in
1884 and Rosing who used a cathode ray tube in 1907 to display images from a mechanical transmitter. In
Britain in 1923, John Logie Baird began to demonstrate television transmission using Nipkow disks. In
America, Rosing’s student, Vladimir Zworykin, filed a patent for an electronic television system in 1923, but
the project was dropped by Westinghouse and Zworykin had to wait for RCA to restart the project in 1930.
Meanwhile, an Idaho schoolboy, Philo Farnsworth, invented an electronic system in 1922, and by 1927 had
transmitted television images. The development of the kinescope and its successor, the image orthicon tube, at
RCA, plus a licensing agreement between RCA and Farnsworth led to the first appearance of commercial TV
in April,1939 at the RCA pavilion at the New York World Fair.
-------------------------------------------------------------------------------John Logie Baird (1888 -1946) graduated from the University of Glasgow and worked for a while as an
engineer for a Glasgow electrical company, but was discharged when he blacked out half the city in an
unauthorized experiment to create diamonds. In the 1920’s Baird began working on television using the
Nipkow mechanical scanning disk. In 1926 he demonstrated the first television. He went on to demonstrate
the first color and stereo televisions and succeeded in recording his video signals on disks. From 1929 to
1935, the BBC used the Baird mechanical television system; in the last part of this period it shared time with
the electronic system. Mechanical systems, however, were limited to about 200 lines per frame and could not
compete successfully against electronic systems.
Philo Taylor Farnsworth (1906-1971), was a 15-year old Mormon high school student in Rigby, Idaho in
1922 when he invented an electronic television system and explained it to his chemistry teacher. In 1926, at
age 19, he received some backing and formed a company to develop television. By 1927 he had obtained his
first patents, obtained financing from a group of San Francisco bankers, and displayed the first electronic
television image. His success was announced in 1928, the first public demonstration was given in 1934, and
by 1936 his studio was broadcasting to about fifty home receivers in Philadelphia. The next years were an
odyssey of litigation as RCA tried to break the Farnsworth patents which blocked the kinescope and orthicon
tubes. The Farnsworth patents were repeatedly upheld and in 1939 RCA agreed to pay royalties to the
Farnsworth company.
Vladimir Kosma Zworykin (1889-1982) was educated in Russia and France and then saw service during
World War I in the Russian Army Signal Corps. After the war he emigrated to the United States and worked
initially for the Westinghouse Electric Corporation where in 1923 he filed a patent application for the
iconoscope, an electronic camera tube using a photo-emissive array. However, it was not until 1929 that RCA
offered him the opportunity to continue working on television. Zworykin’s iconoscope led to modern
televison cameras and Zworykin's kinescope was the basis for the modern television picture tube. His other
inventions included a form of the electric eye and his infrared image tube led to the sniperscope and the
snooperscope. He also invented a secondary-emission multiplier used in scintillation counters.
VI. Radar
In the period before World War II, all the major powers were developing radio location systems. The British
concentrated on aircraft detection and location while the Germans developed aircraft navigation systems.
These devices operated at meter wave lengths. The invention of the multicavity magnetron by Randall and
Root in Britain in 1939 provided the impetus to the development of the centimeter wavelength systems
required for modern radar. The disclosure of the device to the U.S. in 1940 was followed by the founding of
the Radiation Laboratory at MIT. The Radiation Laboratory technical staff grew to more than 1300 engineers
and scientists, including ten future Nobel Laureates, and developed more than one hundred models of radar,
including early warning systems, anti-aircraft gun-laying radars, anti-submarine radars, ground approach
systems, and bomber targeting radars. Other radars were developed at Bell Labs and elsewhere. Nearly one
million radar sets were produced in the U.S. as the war progressed! The Germans and the Japanese also
produced a variety of radar systems. However, the Germans never produced the short wavelength systems
available to the Allies and were caught in a losing game of technical catch-up. The Japanese, who had
independently invented the magnetron, were hampered by bureaucratic entanglements, military secrecy and
personnel shortages as engineers were regardlessly drafted into the army.
-------------------------------------------------------------------------------Robert Alexander Watson-Watt (1892-1973), a descendant of James Watt, received a degree in Electrical
Engineering from the University of St. Andrews, Scotland and in 1915 began a career in the British civil
service, He patented his first radio location device, a device for locating atmospheric discharges, in 1919. In
1935, he received his eleventh radio-location patent, a device for detecting and locating an approaching
aircraft. In the following years he was the leader of the intensive development of aircraft radio-location, the
secret weapon of the Battle of Britain. In 1937, before the war began, Watson-Watt and his wife undertook
the dangerous task of traveling disguised as ordinary tourists through Germany, searching for signs of
German radar stations.
Alfred Lee Loomis (1887-1975), a graduate of Yale and Harvard Law School, was called "the last of the great
amateurs of science". Loomis made a fortune on Wall Street and used his wealth to play host at his estate to
famous physicists and to finance a private electronics laboratory; he had already built a working low-power
CW radar for aircraft detection when the British brought the magnetron to the U.S. in 1940. In the following
months, Loomis helped found the Radiation Laboratory and became head of the Microwave Committee of the
National Defense Research Committee. In 1940, Loomis conceived the idea of a precision long-range radio
navigation system, Loran. By 1942, the first Loran system, operating at 1.95 MHz, was operating along the
East Coast and was used to direct surface vehicles the location of aircraft attacking submarines. Loomis is
also credited for conceiving the conical scan system for automatic radar tracking of targets.
Isador Isaac Rabi (1898-1988) was brought to the United States at age three by his parents to escape the
poverty of Eastern Europe. His father labored in the sweatshops of New York City and then opened a grocery
store in Brooklyn to escape the tenements of Manhattan. Rabi earned his degrees at Columbia and Cornell,
and became a professor of Physics at Columbia in 1937. In 1940, Rabi took leave from Columbia to become
director of research at the newly-formed MIT Radiation Laboratory. Rabi, who hated the Nazis, would
respond to any proposed project by asking, "How many Germans will it kill?" The projects under his
immediate direction involved increasing the power and frequency of the magnetron oscillators. In 1944 He
was awarded the Nobel Prize for his (1937) invention of the magnetic resonance method for determining
atomic spectra.
Luis Walter Alvarez (1911-1988) was one of the most versatile of the physicists who worked at the Radiation
Laboratory. Alvarez, who was of Irish-Spanish descent, was the son of a prominent Mayo Clinic physician.
He began his career as a nuclear physicist at Berkeley in 1937 and made a number of fundamental
discoveries. In 1940 he joined the Radiation Laboratory staff and invented the Ground-Controlled Approach
radar for aircraft landing, a microwave early warning radar, and a precision high-altitude bombing radar. In
1944 he transferred to the Manhattan project, where he invented the implosion system for initiating atomic
explosions. He was awarded the Nobel prize in 1968 for his development of the hydrogen bubble chamber
and the discovery of many subatomic particles. In 1980, he and his son, a geologist, co-authored the theory of
the catastrophic annihilation of the dinosaurs as the result of a massive meteorite impact.
Edward Mills Purcell (1912-1997) grew up in a small Illinois town where his father managed the local office
of the telephone company. Purcell obtained a BSEE at Purdue and then turned to Physics. He was an
instructor at Harvard until he joined the newly formed Radiation Laboratory where he led a group developing
one centimeter wavelength radar systems. It was discovered that these systems were limited by absorption by
atmospheric water vapor. This work put him on the track to his 1945 discovery of nuclear magnetic resonance
in liquids and solids, the basis for NMR medical imaging. In 1952 he was awarded the Nobel prize for this
discovery.
Robert Henry Dicke (1916-1997) delayed his arrival at the Radiation Laboratory in order to finish his
dissertation in Physics at the University of Rochester. Dicke’s inventiveness led to 35 radar-related patents.
He invented mono-pulse and coherent-pulse radar and devices such as the magic-T waveguide junction. To
measure water vapor absorption at centimeter wavelengths, Dicke invented a radiometer which became the
standard detector for radio astronomy. Dicke later became a professor at Princeton. He challenged Einstein’s
general theory of relativity and conducted a series of gravity experiments which were eventually unsuccessful.
He also correctly theorized that a microwave echo from the Big Bang that created the universe could be
detected.
VII. Electrons and Waves
The revolution in physics which was introduced by the emergence of the quantum theory of matter led to the
invention of the devices of modern electronics. The roots of the quantum theory lie in unanswered questions
of 19th Century Physics, which were resolved in 1927 by the Schrödinger theory which encompassed the
wave/particle duality of radiation and matter discovered by Planck and DeBroglie. The quantum theory
provided the foundation for the theories of conduction in metals and semiconductors which form the basis for
solid state electronics. The physicists who created this scientific revolution were, for the most part, Europeans
whose lives and work were disrupted in the 1930’s as many became refugees from Hitler.
-------------------------------------------------------------------------------Ludwig Eduard Boltzmann (1844 - 1906) was born and educated in Vienna, and held positions at Vienna,
Graz, Munich and Leipzig. Boltzmann’s work in statistical mechanics used the concepts of probability to
determine physical properties and contributed to the development of quantum mechanics. His work was met
with hostility by many scientists: depressed and ill, Boltzmann committed suicide.
Max Karl Ernst Ludwig Planck (1858-1947), was one of the leaders of science in Germany until his
retirement in 1928. In 1900 he "guessed" the correct form for the blackbody radiation function and attempted
to justify the formula by assuming that radiation consists of quanta of energy. Using the formula, Planck was
able to deduce the value of h, the Boltzmann constant k, Avogadro’s number and the charge of the electron;
he received the Nobel Prize in 1918. Plank, whose career was marked by its devotion to the highest ideals,
died broken by a series of personal tragedies: his elder son was killed in World War I, his daughters both died
in childbirth in the next decade, and his second son was implicated in the plot against Hitler and executed
horribly by the Gestapo in 1945.
(Prince) Louis-Victor de Broglie (1892-1987) and his elder brother, members of the French nobility, broke
with family tradition and became physicists. His interest in conceptual problems in physics led to a doctoral
thesis which evoked the astonishment and skepticism of the examining committee. He proposed that electrons
had wave properties; this duality of matter and waves offered an explanation of the restricted motion of
electrons around atomic nuclei. A copy of his thesis reached Einstein, whose enthusiastic response led in turn
to Schrödinger’s invention of wave mechanics.
Erwin Schrödinger (1887-1961) was an Austrian Catholic who left Germany in 1933 in response to Nazi
policies. After the Nazi takeover, he and his wife then fled Austria with a single suitcase to take refuge first in
the Vatican and, later, in Ireland. Schrödinger’s theory replaced the definite atomic particles of classical
theory with an equation for a wave function which is related to the probability of physical events. Oddly,
Schrödinger was unhappy with his own invention and spent great effort in formulating objections to his
theory. Schrödinger was a widely talented individual who not only wrote popularizations of science, but also
contributed works on genetic structure, ancient Greek philosophy, and the history and philosophy of science.
Enrico Fermi (1901-1954), was the son of an Italian railroad employee. He received his doctorate from the
University of Pisa at age 21. In 1926 he developed the statistical method which predicts the behavior of
electrons and, shortly thereafter, was made a full professor at the University of Rome at age 26. In 1938, he
left Italy with his family to receive the Nobel Prize and did not return; his known distaste for the Fascist
regime and the fact that his wife was Jewish had led to vicious attacks in the rightist press. Fermi emigrated to
the United States where, as part of the Manhattan Project at the University of Chicago, he led the team that
achieved the first self-sustaining nuclear chain reaction
P.A.M. Dirac (1902-1984) received a degree in Electrical Engineering from the University of Bristol,
England, but failing to find work, went on to graduate study in Physics. He became one of the founders of
quantum mechanics, predicted the existence of the positron, developed the theory of the spinning electron and
introduced the quantum theory of radiation. He was awarded the Nobel Prize in 1933.
Felix Bloch (1905-1983) was at the University of Leipzig in 1928 when his doctoral thesis provided the
theory of electrons in lattices which is the basis for the quantum theory of electrical conduction. Bloch was a
Swiss Jew who left Germany and emigrated to the United States when Hitler came to power. He worked on
the Manhattan Project during World War II. In 1952 he was awarded the Nobel Prize for his work on nuclear
magnetic resonance. Bloch has been called "the Father of Solid-State Physics". In the Bloch theory, electrons
exist as waves in the solid lattice. Interference between the waves and the lattice results in the exclusion of
certain energy bands for the electrons in the solid.
(Sir) Rudolph Peierls (1907-1995), the son of a Jewish businessman, was born and educated in Germany but
sought a post in Britain after Hitler came to power. He became a naturalized citizen and a professor of
Physics, first at Birmingham and later at Oxford. In 1929 Peierls conceived the theory of positive carriers,
electron defects or "holes", to explain the thermal and electrical conductivities of semiconductors and their
negative Hall coefficients. In 1940, Peierls and Frisch alerted the British government of the possibility of
producing an atomic bomb. There was some initial security difficulties, created, oddly, because of Peierls’
German background, but Peierls was eventually sent to work at Los Alamos.
(Sir) Alan Herries Wilson (1906-1976) was a British physicist on a fellowship in the same Zurich laboratory
as Bloch when, in 1930, he recognized the difference between conductors and insulators; conductors have
only partially-filled upper energy bands so that electrons in this band can acquire kinetic energy; the upper
energy band is filled in an insulator. In a semiconductor, the presence of impurities contribute electrons to the
empty upper energy band.
VIII. Transistors
The analogy between the diode and the solid state devices such as the copper oxide rectifier and the crystal
detectors of early radio was obvious early on. During the 1920’s, several inventors attempted devices that
were intended to control the current in solid state diodes and convert them into triodes. Success, however, had
to wait until after World War II, during which the attempt to improve silicon and germanium crystals for use
as radar detectors led to improvements both in fabrication and in the theoretical understanding of the quantum
mechanical states of carriers in semiconductors and after which the scientists who had been diverted to radar
development returned to solid state device development.
-------------------------------------------------------------------------------George Clarke Southworth (!890-1972) was born and raised in a small Pennsyvania town, received his
bachelor’s and master’s degrees from Grove City College and then went to Yale for his PhD. He worked at
the Bell Laboratories from its founding in 1934 until retirement. His work on microwave waveguides in the
early thirties stimulated the development of radar. When he found that triodes would not function as detectors
at microwave frequencies, Southworth turned back to the use of the crystal detectors of the early days of
radio. His source for these was the dusty bins of the second-hand, used radio shops of lower Manhattan.
Russell Shoemaker Ohl (1898-1987) has been called the "forgotten man" in the invention of the transistor.
Ohl was trained in electrochemistry and graduated from Penn State in 1918. In 1927 he went to work for the
Bell Labs Holmdel facility. In 1940, during the course of investigations of the properties of crystal detectors
for radar, Ohl enlisted the assistance of Bell chemists in preparing highly purified silicon. They were able to
produce ingots with n and p type silicon at opposite ends of the same silicon melt. Ohl discovered the silicon
photodetector (and the first p-n junction device) when a section was accidentally cut across an (invisible)
boundary between p and n regions of a silicon ingot solidifying from a doped melt. The device was shown to
Brattain who surmised that rectification was taking place at an internal surface.
Karl Lark-Horovitz (1892-1958) was an assistant professor at the University of Vienna who came to the U.S.
in 1926 via Canada, was naturalized in 1936, and became a professor of Physics at Purdue. Lark-Horovitz
built Physics at Purdue into a major research department. In 1942, Lark-Horovitz and his group began
concentrating on the extraction of purified germanium crystals for use as detectors for microwave radar; they
also began doping the germanium with other elements to determine how the rectification properties were
affected. In 1943 they succeeded in developing a very high back-voltage unit that was mass-produced for use
in radars. The Purdue physicists openly described their results at technical meetings and to Bell Laboratory
personnel who came to Purdue. They were unaware that the flow of information was one-way; Bell
Laboratory had made semiconductor research company confidential. It is believed that Lark-Horovitz and his
group were within a few months of discovery of the transistor.
William Bradford Shockley (1910-1989) was born in London, but grew up in California and was educated at
Cal Tech and MIT. He joined the staff of Bell Telephone Laboratories in 1936. Beginning in 1939, Shockley
began to seek a way of converting a crystal rectifier into an amplifying device. The war interrupted his work,
but it was resumed in 1945 when Shockley returned to Bell Labs as co-leader of the Solid State Physics
research group. The group included Bardeen and Brattain, who invented the point-contact transistor. Shockley
invented the junction transistor a few weeks later. Shockley had a grating personality, and both Bardeen and
Brattain eventually left the group in irritation. In the 1970’s, Shockley aroused a storm of criticism when he
made public a theory of a genetic factor in intelligence which implied an inferiority of blacks; in the 1980’s he
aroused a storm of scornful amusement when he announced that he had left frozen samples of his (70-year
old) semen for the artificial insemination of women of high intelligence.
Walter H. Brattain (1902-1987) was born in China, the son of an American teaching school in Amoy, and
grew up on a ranch in Washington. He received his degrees from Whitman College, the University of Oregon
and the University of Minnesota. In 1929 he went to work for Bell Laboratories, investigating the behavior of
copper-oxide rectifiers until interrupted by the war, when he became involved in radar silicon detector
development. After, he returned to work in the Solid State Physics group where he and Bardeen invented the
point contact transistor. Brittain was the experimentalist, Bardeen the theoretician, but they worked closely
together in the laboratory.
John Bardeen (1908-1991), the son of the dean of the University of Wisconsin Medical School, received a
PhD in mathematical physics from Princeton, taught at the University of Minnesota, and was the principal
physicist at the Naval Ordnance Laboratory during World War II. After the war he was hired by Bell
Telephone Laboratories (at nearly twice his academic salary) to work on theoretical problems of solid state
physics. The breakthrough that led to the invention of the point-contact transistor in 1948 came when Bardeen
developed a theory of the quantum surface states of electrons which led to the conclusion that a charge layer
existed at the free surface of semiconductors. Bardeen left Bell Labs in 1951 to become a professor of
electrical engineering and physics at the University of Illinois. He shared the 1956 Nobel prize with Shockley
and Brattain for their joint invention of the transistor. He also shared the 1972 Nobel prize with Cooper and
Schrieffer for the development of the theory of superconductivity, and thus became the first to win two Nobel
prizes.