. 17
( 21)


attacks on other physicists, that are characteristic impaired heart enlarges to maintain its output,
of his career. Soon after his own work had aided in accord with this law, and the enlargement
proof of relativity theory, quantum theory and (detectable by X-radiography) is an indication of
Bohr™s atomic theory, Stark attacked them. Then in heart damage.
Staudinger, Hermann [shtowdinger] (1881“1965)
1920 he resigned his chair at Würzburg and, using
his Nobel Prize money, attempted a career in the German organic chemist: the founder of polymer
porcelain industry. Failing in this, he tried to chemistry.
return to academic life, despite having antago- Staudinger™s career in chemistry began with
nized almost all his fellow physicists. By 1934 he work of a classical organic kind and included the
was in opposition to most of modern theoretical discovery of a new group, the ketenes, and work on
physics, with his condemnation of ˜all Jews and the aroma agents in coffee. But in the 1920s he
their theories in science™ and his admiration for began to study rubber. At that time, rubber and
Nazi politics, shared by Lenard. Eventually, with other apparently non-crystalline high-molecular
his attempt to control all German physics, his posi- mass materials were supposed to be merely disor-
tion even within the Nazi party deteriorated, and derly aggregates of small molecules; linked with
he retired to his Bavarian estate in 1939. He had this concept, their chemistry was held in low
done notable work in physics when young; his regard. From 1920, working in Zürich and Freiburg,
later influence was malign. In 1947 a German Staudinger took the view that these polymers are
Denazification Court sentenced him to 4 years in a giant molecules held together by ordinary chemi-
labour camp. cal bonds and frequently forming long-chain mole-
Starling, Ernest Henry (1866“1927) British physi- cular strands. His view was at first strongly
ologist: a pioneer of endocrinology and of modern opposed, but he devised methods for measuring
cardiovascular physiology. their relative molecular mass by viscometry, and
Starling was very much a Londoner and, except chemical methods for modifying polymers, and
for short periods in Germany and during his work soon X-ray studies also supported his views. When
for the Royal Army Medical Corps on poison gases accepted, these ideas formed a philosophy for the
in the First World War, his career was spent at new macromolecular chemistry “ the chemistry of
University College, London. Much of his best- ˜high polymers™ (ie having high molecular mass).
known work was done with his friend, brother-in- This has proved fundamental for an industry using
law and co-worker W M Bayliss (1860“1924), who synthetic polymers as rubbers, mouldable plastics,
was a professor of physiology in the same college. fibres, adhesives and so on. He also foresaw the
Their joint work would predictably have gained importance of natural biopolymers in biochem-
them a Nobel Prize but for the war; and Starling™s istry, and from 1936 had some prophetic insights in
acid public comments on Britain™s leaders largely that area, (eg ˜every gene macromolecule possesses
excluded him from the honours awarded to Bayliss, a definite structure which determines its function
including a knighthood. In their early work in life™ “ correct, but not provable for another two
together, they discovered the peristaltic waves of decades). Belatedly, he received a Nobel Prize in
the intestine. Then in 1902 they showed that the 1953. He had then worked in Freiburg since 1926.
Stefan, Josef [shtefan] (1835“93) Austrian physi-
pancreas still produces pancreatic digestive juice
when food enters the duodenum, even when all the cist: discovered the Stefan“Boltzmann black body
nerves to the pancreas are cut. Pavlov™s work had radiation law.
indicated this to be a nerve-controlled process. After 4 years at the University of Vienna, Stefan
They concluded that a chemical messenger (they became a school-teacher for 7 years, researching in
named it secretin) must be carried by the blood physics in his spare time, but in 1863 he secured the
from the duodenal wall to the pancreas, stimulat- professorship of physics at Vienna and remained
ing its activity. They found that an extract from the there throughout his life.
duodenum has this effect; and in 1905 Starling A skilful experimentalist, Stefan measured the
used the word hormone (from the Greek hormeo, to thermal conductivity of gases accurately and
excite) to describe such potent biochemical mes- thereby gave early confirmation of Maxwell™s
sengers. They had created the subject of endocrinol- kinetic theory. In 1879 he considered the heat
ogy, which was later to prove so fruitful. Soon it was losses of very hot bodies, which were reputed to
realized that one hormone had already been found cool faster than Newton™s law of cooling predicted.
(adrenalin, by Takamine in 1901); another was dis- Using Tyndall™s results obtained with a platinum
covered by Kendall in 1914 (thyroxin), and the sub- wire made incandescent by passing a current,
ject expanded strongly after 1930. Stefan showed that the rate of heat loss per unit
area is E = σT4, a relation known as Stefan™s Law.
Starling™s other work was largely on the cardio-
Here σ is now known as Stefan™s constant and T is
vascular system. Starling™s law of the heart (1918)
states that for cardiac muscle (as for voluntary the absolute temperature. In 1884 his ex-student
muscle) the energy of contraction is a function of Boltzmann used the kinetic theory and thermody-
the length of the muscle fibres. So the more the namics to derive this law, and showed that it only
heart is filled during diastole (relaxation) the held for bodies radiating perfectly at all wave-
greater is the following systole (contraction); this lengths, called black bodies. It became known as
allows change in output without change in rate. An the Stefan“Boltzmann Law. Stefan used the law to
Panel: The entry of women into the biological sciences

THE ENTRY OF WOMEN INTO she was later to be appointed curator of the Hamburg
Unlike astronomy, women in the biological sci-
The biological sciences were relatively more welcom- ences could provide for themselves, if self-financing,
ing to women than the other sciences, and fewer the laboratory equipment needed. ELEANOR ORMEROD
obstacles were placed in their path. Unlike medicine, gained experience in the use of the microscope
botany was regarded as an acceptable occupation for through her brother™s interests and became an expert
women, combining fresh air and exercise with the on insect infestations. Although largely self-taught,
accomplishments of drawing and painting. Painting she became recognized as an authority on agricul-
led a number of women towards botany and zoology. tural entomology by Edinburgh University with an
Maria Sibylle Merian (1647“1717), one of the earliest honorary LlD in 1900.
female entomologists, had a business in Amsterdam During the later part of the 19th-c university edu-
selling silk, hand-painted with flower designs. She cation became available to women. In the USA
initially studied caterpillars in order to find other vari- women such as the twin sisters Agnes and Edith
eties than silkworms which could be used to provide Claypole (1870“1954/15) gained science degrees
fine thread. She spent two years in Surinam collecting and moved into teaching in higher education. Edith
and painting insects and plants; her Metamorphosis died of typhoid fever contracted during her research
Insectorum Surinamensium was published in 1705. on the typhoid bacillus. Mary Brandegee
Many women took up botanical illustration, as accu- (1844“1920) gained an MD degree in 1878 at the
rate illustrations were needed to distinguish the dif- University of California and became interested in
ferent species and varieties. Madeleine Frances medicinal plants; with her husband she founded a
Basseport (1701“80) was an illustrator for the French journal of botanical observations. Clara Cummings
Royal Gardens 1735“80, and there are over 700 (1853“1906) studied at Wellesley College and joined
drawings of fungi by Anna Worsley Russell (1807“76) the staff; she specialized in cryptogamic (spore-pro-
in the British Museum. ducing) flora. NETTIE STEVENS was a student at
Botany began to be popular among women as a Stanford University and gained her PhD in 1903
hobby with the publication of a number of books under T H MORGAN at Bryn Mawr. She found the chro-
written by women for women. Priscilla Bell Wakefield mosomal basis of sex-determination, but died before
(1751“1832) wrote an Introduction to Botany as the importance of her work and her reputation were
letters from one sister to another, explaining the fully established. In Britain, ETHEL SARGANT went to
Linnaean system of classification; it ran into 11 edi- Girton College, Cambridge and took the natural
tions by 1840. When the Botanical Society of London science tripos examination in 1885. She carried out
was formed in 1836, about 10% of the members research in cytology and in anatomical morphology,
were women. One member, ANNA ATKINS, led the use working from a laboratory at home. Her best-known
of photography in place of drawing to illustrate scien- work concerned the anatomy of seedlings; she
tific books. She used J F W HERSCHEL™S ˜cyanotype™ suggested a new interpretation of the relationship
process (1842) to make contact prints of her collec- between mono- and dicotyledons.
tion of algae and produced Photographs of British Cambridge occupied a key position in the educa-
Algae: Cyanotype Impressions (3 vols, 1843“53). tion and training of the first generation of British
Elsewhere in Europe women were taking an interest women scientists. Those at Girton and Newnham
in botany. Amalie Konkordie Dietrich™s (1821“91) were only accepted by their colleges if they were
special interest was in the alpine flora of Europe and candidates for the tripos (honours) examination, and

make the first satisfactory estimate of the tempera- Schwartz (1932“ ) and L Lederman (1922“ ) at
ture of the Sun™s surface (the photosphere), arriving Columbia University, New York, from 1959. They
at 6000°C for this. theorized that neutrinos should be of two kinds,
Steinberger, Jack [stiynberger] (1921“ ) US nuclear the electron neutrino and the muon neutrino. In
physicist: a major contributor to the ˜standard the early 1960s a new high-energy proton accelera-
model™ of particle physics. tor became available at the Brookhaven National
Steinberger went to the USA in 1934 as a teenage Laboratory, which could provide enough neutrinos
Jewish refugee, and later studied chemistry at to test their theory. To exclude other particles, a
Chicago. In the Second World War he worked in the filter was used consisting of a stack of steel plates
radiation laboratory at Massachusetts Institute of from a scrapped battleship, 13.5 m thick. Behind
Technology and his interest moved to physics; as a this a detector located a few nuclear reactions that
result, he worked for his PhD in Chicago on the confirmed that two kinds of neutrino exist.
muons present in cosmic rays. He showed that a Working in Europe at CERN near Geneva from
muon decays to give an electron and two neutrinos; 1968, Steinberger continued to use neutrinos to
and he continued his work in this field with M study nuclei and nuclear forces. The current ˜stan-
Steno, Nicolaus

so formed a body of especially able students. world™s expert on the higher level classification of
Although at this stage the women were not granted arthropods, and IRENE MANTON in 1961, who set up
degrees, only certificates of proficiency, they were the first laboratory in the world for the ultrastructural
attracted to the high quality of teaching as the study of plants using the electron microscope.
women were permitted to attend the university lec- By now the pathway to honours was well trodden
tures if they had the consent of the lecturers. They by women in the biological sciences. Honor Bridget
were not officially part of the university and so were Fell (1900“86) became an FRS in 1952, and studied the
barred from university prizes and scholarships and cellular interactions of cartilage and bone. Helen Kemp
restricted in their use of the library. Such opposition Porter (1899“1987), elected in 1956, was interested in
seemed to create a challenge to which the women starch metabolism and became one of the first investi-
rose, often gaining higher marks than the male gators to apply chromatography and radioactive
prizewinners. The presence at Cambridge of Emily tracers to prepare radioactive biochemicals and use
Davies (1830“1921), Girton™s founder and a promi- them to study the intermediate metabolism of plants.
nent figure in the reform of female education, put Sheina Macalister Marshall (1896“1977), a marine
Cambridge in a prime position to provide first-class biologist, was elected in 1963. JEAN HANSON, the co-
women science teachers for the best of the newly deviser of the sliding-filament theory of muscle con-
opened girls™ schools, which in turn brought a steady traction, was elected an FRS in 1967. Mary Winifred
supply of well-taught, able women students to the Parke (1908“89), elected in 1972, was an all-round
Cambridge tripos courses. Opportunities for research expert on algae. In 1991 ANNE MCLAREN, an embryolo-
in biochemistry and physiology at Cambridge were gist elected an FRS in 1975, became the first woman to
the result of such good training. F G HOPKINS, hold office in the Royal Society™s 330-year history, by
regarded as ˜the father of biochemistry™, at a time taking the post of Foreign Secretary.
when the opportunities for research biochemists in During the later half of the 20th-c women began
British universities was minimal and when there were to win Nobel Prizes in physiology or medicine,
few women research workers in other university despite their difficulty in obtaining senior academic
posts. GERTY THERESA CORI, n©e RADNITZ, shared a
departments, provided research places for women in
his department despite the criticism this caused. Nobel Prize with her husband in 1947 for their discov-
The 20th-c has seen the emergence of women ery of the course of the catalytic conversion of glyco-
among the highest achievers in the biological sci- gen in animal cells. In 1977 ROSALYN YALOW received
ences. In 1945 MARJORY STEPHENSON, who researched hers for the development of radioimmunoassays of
under Hopkins at Cambridge, became the first peptide hormones, now routinely used in clinical
woman to be elected a Fellow of the Royal Society in diagnosis. In 1983 BARBARA MCCLINTOCK received the
the biological sciences; she worked on bacterial prize, unshared, for her discovery of mobile genetic
metabolism. The following year AGNES ARBER was elements (˜jumping genes™). RITA LEVI-MONTALCINI
honoured; her researches in Cambridge were con- was awarded hers jointly with Stanley Cohen for their
cerned with the anatomy and morphology of mono- discoveries of nerve growth factors in 1986. GERTRUDE
cotyledonous plants. In 1947 Muriel Robertson BELLE ELION was awarded the 1988 Nobel Prize for
(1883“1973) was elected an FRS; she worked on pro- physiology or medicine jointly with GEORGE HITCHINGS
tozoa, especially the trypanosomes that cause sleep- for ˜introducing a more rational approach based on
ing sickness, and on bacteriology and immunology. the understanding of basic biochemical and physio-
The only sisters to both achieve an FRS were SIDNIE logical processes™ to the synthesis of novel drugs.
MILANA MANTON, elected in 1948, who was the

dard model™ for nuclei proposes two types of com- The present picture of the fundamental particles
ponent as fundamental units of matter: the quarks of matter will certainly change in the future,
and the leptons. Of the six kinds of quark, three probably with the development of higher energy
have electric charge 2/3 and three have “1/3 of a particle accelerators, as in the past. Steinberger,
proton™s charge. All are subject to the strong Lederman and Schwartz shared the Nobel Prize for
nuclear force. They also have a new form of charge physics in 1988.
Steno, Nicolaus (Lat), Niels Steensen (Dan) [steenoh]
(˜colour™) and ˜spin™. None have been found free;
they are permanently confined in nuclei. All (1638“86) Danish anatomist and geologist: made
matter is made of quarks (eg the proton and the early studies of crystals and fossils.
neutron are made of three quarks, of different An anatomist by training, Steno was also inter-
kinds) together with leptons, which are also of six ested in crystals and fossils. He showed that a
kinds. Leptons are light particles (electrons, pineal gland like that of man is found in other ani-
muons, tau and their neutrino partners ). The neu- mals, and used this and other arguments to refute
trinos interact only through the weak nuclear Descartes™s claim that it is the seat of the soul
force: muons and tau particles are short-lived. and uniquely human. His study of quartz crystals
Stephenson, Marjory

revealed that, although the shapes varied, the magnetic field should be found in two (spin-up or
angle between corresponding faces is fixed for a spin-down) configurations, so that the beam would
particular mineral. This constancy, sometimes be split into two distinct beams by such a field.
called Steno™s Law, is a consequence of the internal Such quantum mechanical space-quantization was
ordering of the constituent molecules in the crys- proved by the Stern“Gerlach experiment, and Stern
tal. Steno also accepted the organic nature of fossils was awarded the 1943 Nobel Prize for physics.
and recognized that sedimentary strata were laid Stern took a professorship at Hamburg and set up
down in former seas, having found fossil teeth far a large molecular-beam laboratory, collaborating
inland that closely resembled those of a shark that with Pauli, Bohr and P Ehrenfest (1880“1933).
he had dissected. His geological sections were prob- Stern determined the magnetic moment of the
ably the first to be drawn. proton and found it to have two to three times the
He became a priest in 1675, was ordained a bishop value predicted by Dirac. In 1933 Stern moved to
in 1677 and gave up science thereafter. Carnegie Institute of Technology, Pittsburgh, but
Stephenson, Marjory (1885“1948) British bio- the momentum of the Hamburg laboratory was not
chemist and microbiologist: the first female Fellow regained and he retired early. He enjoyed luxury,
of the Royal Society in biological sciences. good food and the cinema, and it was in a cinema
Marjory Stephenson™s father was a Cambridge- that he died of a heart attack at 81.
Stevens, Nettie (Maria) (1861“1912) US cytologist:
shire farmer with an interest in applied science; he
read Darwin and Mendel and began fruit growing elucidated the chromosomal basis of sex determi-
in a region previously without orchards. It was he nation.
who explained nitrogen fixation to Marjory as a For over 2000 years speculation and some experi-
child when they walked together in a clover field, ments had been directed to an obvious biological
but it was her mother who oversaw her education question: what determines whether a living organ-
and pressed for her to enter university at a time ism (including the human) is male or female? Only in
when this was a novel path for girls. the early 20th-c was it shown that this is fixed at the
She studied at Newnham College, Cambridge point of fertilization and depends on the chromo-
(1903“06) and became a teacher of domestic science somes of ovum and sperm, and not, for example, on
for a short period, but then began biochemical the external conditions of early growth. Of the sev-
research in London in 1911. When the First World eral biologists concerned, Nettie Stevens was almost
War broke out she joined the Red Cross, serving certainly the first to carry out the crucial experimen-
with distinction in France and in Salonika. tal work and to clearly appreciate its result.
Afterwards she joined F G Hopkins in research back She was 35 when she became a student at Stanford
in Cambridge, and spent the rest of her life in the University, having saved money from working as a
Biochemical Laboratory there, working at first with teacher, and after graduation she went to Bryn
him on vitamins but from 1922 making her own Mawr in 1900 to research for a doctorate. She was
mark in the study of bacterial metabolism and fortunate that the small college for women then
becoming the leading expert on the enzymes that
control this. She was able to show that these
enzymes were essentially similar in nature and
activity to those of higher organisms.
She did much to establish bacterial chemistry as a
valuable branch of biochemistry. Many researchers
were trained by her in microbiology, and it was no
surprise that she was one of the first two women to be
elected Fellows of the Royal Society in 1945, together
with the crystallographer Kathleen Lonsdale. (See
panel on pp. 329“30.)
Stern, Otto (1888“1969) German“US physicist:
showed that magnetic fields of atoms are quantized.
Otto Stern, the son of a grain-merchant, com-
pleted his doctorate in Breslau in 1912. He travelled
and attended lectures by Sommerfeld, Lummer and
E Pringsheim and became a post-doctoral associate
and friend of Einstein in Zürich. Following mili-
tary service during the First World War he worked
with Born in Frankfurt on statistical mechanics.
In 1920 Stern and W Gerlach (1889“1979) collabo-
rated in a historic experiment. A molecular beam of
silver atoms (produced by heating the metal in a
vacuum) was used to investigate whether space
quantization (proposed by Sommerfeld) occurs or
not. A silver atom should possess a magnetic
moment (spin) and when placed in a non-uniform Nettie Stevens
Stokes, Sir George Gabriel

had the eminent geneticist T H Morgan to teach
biology: later he was to claim her as the most tal-
ented of his many graduate students.
Although Leeuwenhoek had observed spermato-
zoa with a primitive microscope in the 1670s, it was
not until the late 19th-c that the use of new staining
and fixing methods, together with improved com-
pound microscopes allowed cytologists to observe the
entry of the sperm nucleus into the ovum (egg) cell
and its fusion with the egg nucleus. Sexual reproduc-
tion could now be seen as involving the fusion of two
sets of chromosomes, one from each parent (meiosis).
Nettie Stevens obtained her PhD in 1903, studied
in Europe for a year, partly with Boveri, and
returned to Bryn Mawr to work on ˜the question
how sex is determined in the egg™ as she put it, at George Stibitz in 1937
first by studying the chromosomes of several
Stibitz, George Robert (1904“95) US computer
insects and comparison with the sex of the prog-
eny. Her success came in 1904 with the common scientist.
mealworm Tenebrio molitor. She found that the Stibitz attended colleges in New York, emerging
sperms were of two kinds; their nuclei had either with a PhD in physics from Cornell and then join-
10 large chromosomes, or nine large and one small. ing Bell Telephone Laboratories in 1930. He was
The egg nuclei all had 10 large chromosomes. The there until 1941 when he moved to defence work,
somatic cells of the female offspring have 20 large and from 1945 worked on the computer modelling
chromosomes, those of the male have 19 large and of biomedical systems. He designed the first gen-
one small; Stevens concluded that the former uinely binary calculator in 1937, followed by a
result from X,X fusion and the latter from X,Y series of machines for Bell including the first multi-
fusion. Studies of some other species gave similar user machine, which was demonstrated as a
results, since X,X fusion to give a female embryo remotely controlled device in 1940 using telephone
and X,Y to give a male is a widespread pattern. lines between Hanover, NH and New York City. As
E B Wilson (1856“1939) found essentially similar well as this introduction of remote job-entry, he
results at about the same time, but was later than built the first machine capable of floating point
Stevens in seeing their generality and significance. arithmetic in 1942.
Stock, Alfred [shtok] (1876“1946) German inor-
This understanding of sex determination, and its
linkage with Mendel™s work, which she recognized, ganic chemist: a pioneer of silicon hydride and
is a basic result in biological science of Nobel-prize- boron hydride chemistry and of vacuum handling
worthy importance. But Stevens died from breast methods.
cancer in 1912, before her reputation or the impor- After graduating in Germany, Stock went to Paris
tance of sex chromosomes in genetics was fully estab- in 1899 to join Moissan™s research group. They
lished. By the time science in this area was clarified, were a happy international team, although ˜one
credit had perhaps inevitably focused on T H Morgan, was constantly in danger of losing one™s life™. Later,
who brought together ideas on genes, chromosomes as professor in Breslau, he began work in 1909 on
and genetics, and it was he who received a well- the dangerously explosive boron hydrides; in this
deserved Nobel prize in 1933. (See panel on p. 334.) work he developed the vacuum-line methods so
Stevin, Simon (Dutch), Stevinus (Lat) (1548“1620) much used for volatile materials by later inorganic
Flemish engineer and mathematician: introduced chemists. His work on the boron hydrides led to
decimal notation to Europe. later work on their strange, electron-deficient
Stevin entered the Dutch government service, structures and to their use as rocket propellants.
rising to the rank of Quartermaster-General to the Stock became a victim of mercury vapour poison-
Army, where he developed a system of sluices to ing; he was not the first chemist to suffer this, but
defend parts of Holland from invasion by flooding he was unusual in being aware of the cause of his
them with water. illness, and from 1923 he worked on mercury poi-
He is noted for his demonstration that hydrosta- soning and methods of avoiding it. He also devised
tic pressure in a liquid depends only on the depth a method for making beryllium which is used com-
of liquid and not on the shape of the containing mercially; and the use of P4S3 in place of phospho-
vessel. His booklet De Thiende (1585) publicized the rus in match heads is also due to him.
Stokes, Sir George Gabriel (1819“1903) Irish
decimal system for representing fractions and for
weights, measures and coinage; Napier inventing physicist: a contributor to fluid dynamics.
the decimal point soon afterwards. Stevin wrote an Educated in his native Ireland and at Cambridge,
excellent book on statics, giving the law of the Stokes became Lucasian professor at Cambridge
inclined plane. He was also an advocate of writing in 1849 and in the next half-century did much
scientific works in the vernacular, rather than to rescue physics teaching there. He worked in
Latin, as was the custom of the day. most areas of theoretical and experimental physics
Stoney, George Johnstone

except electricity. One of his enthusiasms was Cambridge, after which he joined Standard
hydrodynamics and another was fluorescence, and Telephones and Cables Ltd. The Second World War
both have laws named after him. Stokes™s Law in hastened the development of electronic comput-
hydrodynamics is that the frictional force (ie drag) ers, and Strachey wrote some of the largest pro-
on a spherical body of radius r moving at its termi- grams for them. In 1951 he joined the National
nal speed ν through a viscous fluid of coefficient of Research and Development Corporation, designing
viscosity n is 6πnrν; this holds only for a restricted the Ferranti Pegasus computer. In 1962 he became
range of conditions. Stokes™s Law of Fluorescence a research fellow at Cambridge and worked on
states that the wavelength of fluorescence radia- the design of the high-level language CPL, which
tion is greater than that of the exciting radiation; led to the more common BCPL (Basic Computer
again, the law does not always hold. Programming Language). He later moved to Oxford
He pioneered in 1849 studies of gravity variations and established the Programming Research Group,
over the Earth™s surface: such geophysical methods working largely on a comprehensive theory of pro-
are now used in stratigraphic studies to assist oil gramming language semantics.
Strasburger, Eduard Adolf [shtrasburger] (1844“
prospecting. An ultrasensitive spring balance
(gravimeter) is used, allowing the acceleration due 1912) German botanist: demonstrated capillary
to gravity (g) to be measured; a low value indicates action as cause for sap rising in trees.
a low density material (oil or water) below. A friend and student of N Pringsheim and an
Stoney, George Johnstone (1826“1911) Irish early enthusiast for Darwin™s ideas, Strasburger
physicist: suggested the name electron for the taught at Jena and later at Bonn, and made the
smallest unit of electricity. latter the major centre for research in plant cytol-
For most of his working life Stoney was secretary ogy. He was the first to fully describe the embryo
to Queen™s University, Dublin. Rightly believing sac in gymnosperms (conifers) and in angiosperms
that science would be simplified by a wise choice of (flowering plants) and to recognize the process of
fundamental units, he argued this in 1874 and pro- double fertilization in the latter. In 1875 he
posed the charge on a hydrogen ion as a unit, cal- described the principles of mitosis and deduced
culating its value from the mass of hydrogen that the nucleus was responsible for heredity, and
liberated on electrolysis. This idea that negative a little later he proposed a basic principle of cytol-
electricity has a ˜smallest unit™ was also advanced ogy: that new nuclei arise only from the division of
by Helmholtz in 1881, and 10 years later Stoney existing nuclei. In 1891 he demonstrated that phys-
introduced the word ˜electron™ for the unit. Later ical forces (eg capillarity) are largely responsible for
the word came to be used for the ˜corpuscles™ dis- the rise of sap in a tree stem, rather than physio-
covered by J J Thomson. logical forces.
Stopes, Marie (Charlotte) (1880“1958) British Strutt, John William, Baron Rayleigh see
palaeobotanist and early advocate of birth control.
Sturgeon, William (1783“1850) British inventor:
Marie Stopes studied botany, geography and geol-
ogy and gained her degree at University College, much improved electromagnet design.
London. She then went to Munich and took a doc- After a few years as an apprentice shoemaker,
torate in 1904, and was awarded a London DSc in Sturgeon joined the army and began to study sci-
1905. In 1904 she became the first woman member ence at night, until he became an expert on electri-
of the science staff of Manchester University. Stopes cal instruments. After he left the army in 1820 he
soon had a leading position in research on fossil became a bootmaker and itinerant teacher of sci-
plants, and was responsible for a useful classifica- ence for the army, and for some schools and soci-
tion of coals on this basis. eties, and he published popular accounts of
Her first marriage was annulled for non-consum- science. In 1821 he much improved the electro-
mation in 1916, and led to her book Married Love magnet by using a bar of soft iron coated with shel-
(1916). In it she argued that women were as entitled lac varnish to insulate it from the bare wires
as men to physical pleasure; it also discussed birth carrying the current (J Henry and Faraday later
control methods. The book was much attacked, and insulated the wires, so allowing many more turns
was banned in the USA, but it led to many enquiries and greater improvement in performance). For his
on contraception which she answered in Wise work on electrical apparatus Sturgeon received a
Parenthood (1918). She married the aviator and prize in 1825 from the Society of Arts; it consisted
industrialist H V Roe (1878“1949) who gave her sup- of a silver medal and 30 guineas. In 1836 he
port to open the first British birth control clinic in invented a moving-coil galvanometer and the first
1921, in north London. Her robust attitude to oppo- commutator for a workable electric motor. He pub-
sition and her forceful and eccentric personality lished the first journals on electricity in English:
helped to change attitudes to sex and contracep- his monthly Annals of Electricity ran from 1836“43.
Sturtevant, Alfred Henry [stertevant] (1891“1970)
tion in the UK.
Strachey, Christopher [straychee] (1916“75) US geneticist: pioneer of chromosome mapping.
British computer scientist: pioneering worker on As a boy Sturtevant drew up pedigrees for his
programming languages. father™s farm horses, and as a student at Columbia
Strachey came from a literary family (Lytton University his older brother encouraged this interest
Strachey was his uncle) and was educated at through books on heredity. A book on Mendelism
Svedberg, Theodor

spurred his enthusiasm, since he felt that some the MRC Laboratory for Molecular Biology in
horse coat colours could be explained on a Cambridge in 1969 and Director of the Sanger
Mendelian basis. He wrote on this to the leading Centre there from 1992 to 2000. Before 1983 he had
American geneticist T H Morgan and in 1910 made a close study of the 1mm long nematode
joined the group of enthusiasts in the crowded worm C. elegans by conventional microscopy: later
˜fly room™ at Columbia, working with Morgan on he was co-leader, with R Waterston of Washington
the genetics of the fruit fly, Drosophila. In 1928 University, St Louis, of a team which decoded its
Sturtevant became professor of genetics at the entire genome by 1998. The worm has only 959 cells
California Institute of Technology, where he and about 20 000 genes, but the decoding needed
remained, except for research visits, until his 15 years work by the team, which involved collabo-
death. ration among 250 laboratories worldwide. By the
In the ˜fly room™ he had the germ of the idea of late 1980s they and other molecular biologists were
chromosome mapping and ˜went home, and spent part of the Human Genome Project (˜HGP™; see
most of the night (to the neglect of my undergrad- panel, p. 368). Their ultimate target was to define
uate homework) in producing the first chromo- the much larger human genome, made up of thou-
some map™. This was based on his idea that the sands of genes, themselves located at as-yet-unde-
frequency of crossing-over between two genes gives fined places within DNA chains involving over
an index of their relative distance on a linear map three billion base-pairs, and forming the 23 human
of the genes on the chromosome. His paper of 1913 chromosome pairs (see diagram p. 31).
located six sex-linked genes, as deduced from the The HGP by the 1990s embraced the Sanger
way they associated with each other; it forms a clas- Centre in association with four major US laborato-
sic paper on genetics. He later developed a range of ries and some hundreds of smaller widespread
related ideas, discovering the ˜position effect™, ie ones. In 1991 the National Institutes of Health (NIH)
the way in which the expression of a gene depends in the USA applied for patents on some DNA frag-
on its position in relation to other genes; and he ments sequenced by a group led by Craig Venter
showed that crossing-over between chromosomes then of NIH. The concept of patenting genetic infor-
is prevented in regions where a part of the chromo- mation was opposed by Sulston and by Watson,
some material is inserted the wrong way round. then head of the HGP, who resigned the next year.
The position effect was to prove of great impor- From then on, work on the human genome effec-
tance in F Jacob (1920“ ) and Monod™s work on tively became a contest between ˜public™ and ˜pri-
gene clusters (operons) in bacteria. Although vate™ sectors. Both had financial backing by the
Sturtevant™s main work was in genetics (where he pharmaceutical industry; but the former (with
worked with a range of animals on an assortment Sulston as a leading figure) supported an ˜open data
of problems, including the curious effect of direc- access™ policy; the latter, led by Venter, saw invest-
tion of shell-coiling in snails) he was also a knowl- ment and commercial possibilities as necessary for
edgeable naturalist, with a special interest in social speedy success. The contestants had different labo-
insects. ratory techniques as well as philosophies. Some
Suess, Eduard [züs] (1831“1914) Austrian geologist: measure of harmony was reached in June 2000, as
proposed former existence of Gondwanaland shown by a joint announcement from Venter (who
supercontinent. left HGP in 1998 and was now President of Celera
Suess was educated at the University of Prague, Genomics) and the HGP team (with Sulston head-
moved to Vienna in 1856 and became professor ing its lead group at the Sanger Centre) reporting a
of geology there in 1861. In addition to being an ˜working draft™ giving the base sequence for most
academic he served as a member of the Reichstat of the genome. This outstanding achievement
(parliament) for 25 years. On the basis of geological leaves much to be done however. The genes, whose
similarities between parts of the southern con- function is to direct formation of the proteins
tinents, including the widespread occurrence in which are the working parts of the body, have yet to
Africa, South America, Australia and India of the be located within the long DNA chains; the major-
fossil fern Glossopteris during the Carboniferous ity of the base sequences (˜junk™) having no known
period, Suess proposed that there had once function. Clinical applications of the data, rich in
been a great ˜supercontinent™ made up of the potential, are yet to come.
Svedberg, Theodor [svayberg] (1884“1971) Swedish
present southern continents, and he named it
Gondwanaland, after a region of India. Subsequent physical chemist: devised the ultracentrifuge.
work has established the former existence of Svedberg entered Uppsala in 1904, hoping to
Gondwanaland beyond doubt, and Suess™s ideas, as apply novel methods to biological problems; he
extended by Wegener, led to modern theories of stayed in the university for life and had fair success
continental drift. in his objective. His main work was in developing
Sulston, Sir John Edward (1942“ ) British mole- the ultracentrifuge, in which a centrifugal force
cular biologist: a leading figure in the sequencing much above gravitational force is produced, which
of the human genome. is powerful enough to ˜pull down™ large molecules
Sulston, educated at Cambridge and doing post- such as proteins. Svedberg™s ultracentrifuges ran at
doctoral work thereafter at the Salk Institute, CA, up to 140 000 rpm, giving fields up to 900 000 g, and
and Columbia, New York, became Chief Scientist of could be used to purify proteins (and other colloids)
Swallow, John

Sydenham, Thomas [sidenam] (1624“89) English
and to confirm Staudinger™s view that these
were giant molecules, of high relative molecular physician: made early studies in epidemiology.
mass (eg Svedberg found relative molecular After 2 months as a student at Oxford, Sydenham
mass = 68 000 for haemoglobin). Since his work left to join the Parliamentary army, and to serve in
ultracentrifuges have been in routine use for sepa- the Civil War under his older brother (who was
rating large biological molecules. He was awarded commander-in-chief in Dorset). After 3 years he
a Nobel Prize in 1926. The unit of sedimentation returned to his studies and graduated in 1648, but
velocity, the svedberg (S), is named after him. in 1651 was again in the war as a captain of horse.
Swallow, John (Crossley) (1923“94) British physi- He was wounded at the battle of Worcester, and in
cal oceanographer: discoverer of strong eddy fields 1655 he married and began his career as a London
in oceanic interiors. physician. He began there his researches on small-
Swallow was a student of physics at Cambridge pox and other fevers, then prevalent in London. He
when the Second World War interrupted his studies pioneered the use of quinine to treat malaria,
and naval service introduced him to the sea. Back at opium for pain relief and iron compounds in
Cambridge after the war, lectures by Bullard anaemia. His scientific approach to the natural
inspired him to do his PhD in the Department of history of disease was new and valuable; he saw
Geodesy and Geophysics, spending the early 1950s infections as specific entities, best treated conserv-
on the survey vessel HMS Challenger, studying deep atively, as described in his influential book The
ocean floors by seismic methods. From 1954 Method of Treating Fevers (1666), which is dedicated to
onwards he was with the Institute of Oceanographic his friend Boyle. He is the major 17th-c clinician;
Sciences and frequently at sea. To study undersea ˜the English Hippocrates™.
Sylvester, James Joseph (1814“97) British math-
currents he devised the ˜Swallow float™, a neutrally
buoyant float which would transmit information ematician: with Cayley founded the theory of
on current and temperature at varying depths and invariants.
whose location could be tracked from a ship. (The Sylvester was born into a Jewish family of nine
first models were made of discarded builders™ alu- children and in 1828 went to the new University of
minium scaffold poles.) The results confirmed theo- London, founded for Dissenters. Vociferous and
ries due to H Stommel (1920“92) on deep currents in hot-headed, Sylvester fought back against the
the Atlantic and revealed a quite unexpected and strong anti-Semitism which he encountered and
important feature of ocean interiors. This was the was sent down for threatening a fellow student
presence of strong eddy fields, rather akin to atmos- with a table-knife. He was admitted to St John™s
pheric weather systems. This discovery much College, Cambridge (1831) and became Second
changed ideas about deep seas generally. Wrangler; however, as someone unable to accept
Swammerdam, Jan (1637“80) Dutch naturalist the 39 articles of the Church of England he could
and microscopist; a pioneer of modern entomology not obtain a degree and only received his
and discoverer of red blood cells. Cambridge MA in 1871, when this restriction was
Swammerdam™s father, an apothecary, had a lifted. He moved to Trinity College, Dublin and
˜museum of curiosities™ and the boy helped with gained his BA in 1841.
this and became a keen insect collector. He studied After a short period teaching science in London
medicine at Leiden (with Steno as a fellow student) (1837), he decided he preferred mathematics and
and graduated in 1667 but he never practised med- started in 1841 a disastrous few months as profes-
icine, despite his father™s protests and financial sor at the University of Virginia. He resigned
pressure. When only 21, he discovered the red because of the authority™s failure to discipline a stu-
blood cells of the frog. Also from the frog, he intro- dent who insulted him. For some years he aban-
duced the nerve“muscle preparation into physiol- doned university life and worked in London as an
ogy. This consists of a leg muscle with its nerve, actuary and then as a barrister, qualifying in 1850.
dissected from a recently killed frog; when the He also took private pupils; one of the best was
nerve is stimulated, the muscle contracts. By Florence Nightingale. Fortunately, in 1850 he met
immersing the preparation in water in a container A Cayley, who rekindled his interest in mathemat-
with a narrow outlet, Swammerdam was able to ics, and the two became life-long close friends. He
show that when the muscle contracts, there is no became professor of mathematics at the Royal
change in its volume, contrary to earlier belief. Military Academy at Woolwich (1855“70) and at the
For the second half of his fairly short life he was newly founded Johns Hopkins University at
a victim of mental illness, but this did not stop Baltimore (1877“83), producing a flood of new
his skilful pioneer work on insects and their ideas in mathematical research and teaching.
microanatomy. His minute dissections of the When he was over 70, he became Savilian Professor
mayfly, bee, tadpole and snail were not surpassed at Oxford (1883“94); failure of his eyesight forced
until, in the 18th-c, the compound microscope was his retirement to London.
much improved. His work showed the complexity He was enthusiastic and inventive to the end of
of small animals (eg the compound eye, sting and his life; at 82 he worked out the theory of com-
mouth of the bee). Much of this work was not found pound partitions. Sylvester™s mathematical style
until 50 years after his death, when it was pub- was brilliant but not methodical, and his creativity
lished as The Bible of Nature (1737). was unfettered by rigour. With Cayley, he inspired
Szilard, Leo

many of the basic ideas of algebraic invariance. He Laboratory at Woods Hole. In the 1960s he worked
also published on the roots of quintic equations on the thymus gland and on cancer, which had
and on number theory. In 1850 he coined the term killed his wife and daughter. He was a man who had
matrix for an array of numbers from which deter- novel and daring research ideas; he ˜thought big™
minants can be obtained. Invariance assumed great and, a keen fisherman, claimed he liked to use an
importance after his lifetime, as much use was ˜extra-large hook™.
Szilard, Leo [zilah(r)d] (1898“1964) Hungarian“US
made of it in quantum mechanics and relativity
theory. physicist: recognized the significance of nuclear
Szent-Györgi, Albert von [sent dyoordyee] (1893“ fission.
1986) Hungarian-US biochemist: worked on vita- Szilard has been described as ˜a difficult child
min C and on the biochemistry of muscle. who grew up to become an impossible adult™. He
Szent-Györgi had four generations of scientists in was imaginative, volatile and immodest. A versatile
his mother™s family, and in 1911 began to study and creative physicist, Szilard had an extraordinar-
medicine at Budapest. By 1914 he had already pub- ily wide-ranging and original mind. He first studied
lished some research on the eye before he was electrical engineering, trained in the Austro-
called into the Austro-Hungarian army. He was Hungarian army during the First World War and
soon decorated for bravery but, in order to return later took a doctorate in physics at Berlin (1922).
to his studies, he shot himself in the arm. Later he Work with von Laue on thermodynamics followed,
was redrafted, but again proved an awkward sol- and led to a paper foreshadowing modern informa-
dier by protesting against the treatment of prison- tion theory (1929). Moving to Oxford and London in
ers. As a result he was sent to a base in Northern 1933, and to the USA in 1938, he began to work on
Italy where a malaria epidemic was raging, but nuclear physics at Columbia University.
within weeks the war was over and he returned In 1934 he had taken the earliest patent on
to complete his medical course. Afterwards he nuclear reactions, covering in general terms the
researched in five countries and received his PhD in use of neutrons in a chain reaction to generate
Cambridge for work on vitamins with F G Hopkins. energy, or an explosion. On hearing of Hahn and
Back in Hungary in the 1930s, he showed that vita- Meitner™s fission of uranium (1938), he immedi-
min C (the anti-scorbutic vitamin, ascorbic acid) ately approached Einstein, in order to write
was in fact a compound he had first isolated in together to President Roosevelt warning him of the
Cambridge in 1928. He also showed that paprika possibility of Germany making atomic bombs.
(Hungarian red pepper) is a rich source of it; in 1937 Together with Fermi, Szilard organized work on
he won the Nobel Prize for medicine or physiology the first fission reactor, which operated in Chicago
for his work on vitamin C. By 1935 he was working in 1942. He was a central figure in the Manhattan
on the biochemistry of muscle; he began the work Project leading to the successful Allied atomic
which was later developed by Krebs on the metabo- bomb, despite the fact that General Groves, in over-
lism of muscle. He also isolated two proteins from all charge of the project, attempted at one point to
muscle (myosin and actin) and showed that they have him interned for the duration of the war,
combined to form actomyosin. When ATP (adeno- judging him to be a security risk. Szilard opposed
sine triphosphate) is added to fibres of this, it con- the direct use of the bomb against the Japanese,
tracts. ˜Seeing this artificial bundle contract was wishing to use it in a demonstration only; and he
the most exciting moment of my scientific career™, forecast the nuclear stalemate after the war in a
he wrote. This work was extended by H E Huxley. 1945 report to the secretary for war. His enthusi-
He also had an exciting Second World War, work- asm for physics, politics and food continued.
ing for the Allies and the underground resistance. After the war Szilard moved to research in molec-
Afterwards, he was offered the presidency of ular biology, doing experimental work on bacterial
Hungary, but he emigrated to the USA in 1947 and mutations and biochemical mechanisms and theo-
directed muscle research at the Marine Biological retical work on ageing and memory.

Takamine, Jokichi [takameenay] (1854“1922) first used the word ˜hormone™ to describe the
Japanese“US biochemist: isolated first hormone animal body™s ˜chemical messengers™ it was real-
(adrenalin; adrenaline, epinephrine). ized that adrenalin was the first hormone to be iso-
Born in the year that Japan opened its ports to the lated in pure form from a natural source.
Talbot, William Henry Fox (1800“77) British
West, Takamine became a product of two cultures:
brought up in the strict Samurai code, he gradu- inventor of negative/positive photographic process.
ated in chemical engineering at Tokyo and then at Talbot, the son of a relatively impoverished offi-
Glasgow. Back in Japan, he worked as a government cer of dragoons, stepson of a rear admiral and
scientist for 4 years and then opened his own fac- grandson of an earl, was educated at Harrow and
tory, the first to make superphosphate fertilizer in Cambridge, where he studied classics and mathe-
Japan. He married an American and in 1890 went to matics and did well in both. He was 12th wrangler
live in the USA and set up a laboratory to make bio- in 1821, and his later researches in mathematics
chemicals. In 1901 he isolated crystalline adrenalin secured him the Royal Society™s Royal Medal in
from adrenal glands. After 1905 when Starling 1838. He also had success as a decipherer of Assyrian

THE DEVELOPMENT OF as gallic acid. The result was fixed by soaking in
PHOTOGRAPHY ˜hypo™ solution, a method due to Herschel. The dried
paper negative could then be oiled or waxed to made
Photography uses two basic principles, both long- it transparent and used to make any number of posi-
known: firstly, a lens to form an image, as in the tive prints (which would be the right way round) by
˜camera obscura™ (a box with a lens in one end that contact printing on sensitive paper, which would be
forms an image on a screen at the other end for an developed, fixed and washed as before. Herschel saw
artist to trace or copy); secondly, the sensitivity to that a glass plate would be better in many ways than
light of some chemical compounds, mostly silver a paper base for the negative, but the film of photo-
halides. Around 1800 THOMAS WEDGWOOD, aided by his sensitive silver salts on glass was fragile and difficult
friend DAVY, tried to use these two principles to make to prepare, even when improved (as proposed by a
stable images, but had little success. He used paper cousin of Ni©pce) by the addition of egg albumen.
soaked in silver nitrate, but it was not sensitive The albumen was replaced by collodion by ARCHER in
enough to use in a camera, and his best results were 1851. Even with this improvement the business of
shadow pictures of leaves and similar objects, making a photographic negative was burdensome,
obtained by placing them in contact with his paper because the film was only sensitive if freshly pre-
and exposing to sunlight, when the uncovered areas pared and still moist. It then had to be developed
blackened. He failed to find a way of ˜fixing™ the immediately, so a portable laboratory was needed.
result, which blackened entirely on viewing in The photography of mountains, wars and tropical
daylight. scenes on wet collodion plates required heroes for its
In France, NIÉPCE had more success using a pewter achievement.
sheet covered in bitumen, although it was his partner The next advance was due to R L Maddox (1816“
DAGUERRE who gained fame. Daguerre used a silvered 1902), a doctor and an enthusiastic photographer
copper sheet treated with iodine, which was sensitive whose asthma was irritated by the ether fumes from
enough to use in a camera. It was slow to respond collodion (which is guncotton dissolved in ether and
and gave an image rich in detail but fragile and later- alcohol). After many trials he found that a suspension
ally reversed. It was also unique, in the sense that (˜emulsion™) of silver salts in gelatin would serve, and
copies could not be made from it. Although used for a film of this on a glass plate could be used dry. This
some 15 years, the method was a dead end and is made photography much easier for the amateur. The
now extinct. realization in the 1870s that storing and warming the
The scheme which led to modern photography and emulsion, ˜ripening™ it, made it more photosensitive
photomechanical printing was devised by TALBOT and was important. It allowed exposure times of 1/25 s or
his friend JOHN HERSCHEL in the late 1830s. Talbot less in place of seconds or minutes, and so moving
used paper sensitized with silver salts, and found that subjects could be photographed. By the 1880s
the slight or invisible ˜latent™ image formed on it in MUYBRIDGE could use cameras to study the rapid
the camera could be ˜developed™ by chemicals such animal movement of horses, men and women.

Talbot, William Henry Fox

cuneiform inscriptions. He began a political career, Talbot exhibited his own ˜photogenic drawings™
becoming MP for Chippenham in 1833, but appar- within weeks at the Royal Institution, but most of
ently found it unsatisfying “ he spent most of that these were merely silhouettes made by superposi-
year honeymooning on the Continent, sketching tion without a camera, and all his results were
with his wife. Like many others, he used a camera much inferior to the daguerrotypes, especially in
obscura as an artist™s aid, but found this frustrating their brilliance and detail. However, Talbot per-
and laborious and, as he said later, ˜the idea sisted in seeing his efforts as competitive with
occurred to me “ how charming it would be if it Daguerre™s. In 1840 he discovered, by chance, the
were possible to cause these natural images to latent image; exposure of his sensitized paper in a
imprint themselves durably and remain fixed upon camera for only a few minutes gave a result which
the paper!™ He experimented on these lines, using could be made visible by ˜development™ in warm
writing paper impregnated with silver salts, whose gallic acid, and then the picture was fixed with
sensitivity to light was well known. In this way he ˜hypo™ which dissolved out unchanged silver. These
made, in 1835, a very small picture of the lattice last two steps were due to others; both had been
window of the small library at his family home, publicly suggested by his friend J F W Herschel in
Lacock Abbey. It is the second oldest surviving pho- 1839 and used by him, but these facts did not deter
tograph, the oldest being by Ni©pce and also show- Talbot from later patenting both uses. Talbot made
ing a window of a family home, photographed from some of his photographs translucent by waxing
the inside. them and then used this negative to make positive
Talbot turned to other interests, but was spurred contact prints, and in this way he obtained lateral
back to action by news of Daguerre™s work in 1839. reversal and reversal of light and shade as in the

Despite these advances, the sensitive film was tion. Modern lenses with several glass elements give
still supported on glass, heavy and breakable, good correction of optical defects while still admitting
and cameras were usually wooden, large and enough light for short exposures, and often allow a
tripod-mounted. Easy popular photography is due to change of focal length (zoom designs) to vary the
George Eastman (1854“1932) of the USA, who made apparent perspective. Autofocus devices use infrared
film-handling simple by mounting the sensitive sensors to allow automatic adjustment of the lens-to-
gelatin emulsion on a strip of flexible plastic film distance, suitable for subjects at different dis-
(originally celluloid), which could be protected from tances. Photosensitive electronic devices measure
light with a length of black paper and then loaded light intensity and adjust lens aperture and/or shutter
into a lightweight camera as a rolled cartridge. speed to ensure that an optimum level of light reaches
From about 1900 this ˜Kodak™ system dominated the film.
popular photography. With EDISON, Eastman also The early photographers were as much concerned
devised the perforated plastic film that made with contact photography as with camera work, and
cine-photography a practical success. From 1927 a the main process used became Herschel™s cyanotype
track on one side of the perforated film met the method, which gave the ˜blueprints™ used by ANNA
need for sound to be linked with the moving ATKINS in the 1840s and which dominated the
image, ensuring a major place for the cinema in production of engineer™s drawings in the 20th-
entertainment. century, until in the 1950s a very different method,
The key element in photography has always been ˜xerography™, based on electrostatic principles, was
the photosensitive silver component in the film, developed by CARLSON.
leading to images in which the dark areas are formed The most recent advance in photography is based
by small particles of metallic silver. Black-and-white on a reusable sensitive surface and an electronic
photographs were the main outcome of both still system and avoids ˜wet chemistry™. A CCD (charge-
and cine photography in its first century, but coupled device) whose surface is made of tiny light-
images in colour were always a target. Herschel sensitive pixels captures the image. Its output is
and later MAXWELL had some early success in colour handled digitally thereafter, and retained on a com-
photography. Only after the Second World War did puter disc or card. The image can be manipulated by
colour become popular, using ingenious thin a PC in many ways: it can be scanned, colours
sandwiches of coloured organic dyes linked with changed, e-mailed, included in a web page, inkjet-
the sensitive silver layer and with development printed, etc. Resolution is determined by the number
methods complex enough to be carried out of pixels in the CCD: 3 megapixels in a mid-price
normally in a commercial laboratory. The Polaroid® camera is common. These assets and its speed and
camera due to LAND uses rapid in-camera colour availability, must lead to a dominant future for digital
processes that are rather costly but provide ˜instant™ photography.
Cameras have also increased greatly in sophistica-

Tartaglia, Niccolo

original scene; as well as the ability to produce Their friendship ended, and controversy over prior-
prints in any number. Talbot was almost alone in ity followed, with Tartaglia emerging as the loser.
quickly seeing the advantages of this. His results Keen on most branches of mathematics, Tarta-
were published in his The Pencil of Nature (1844), the glia™s greatest enthusiasm was in military applica-
world™s first book illustrated by camera photographs. tions. ˜Tartaglia™s theorem™ of 1537 states that a
Anna Atkins had used Herschel™s ˜cyanotype™ process firing elevation of 45° gives the maximum range
to illustrate her book on algae published in 1843, for a projectile regardless of the speed of projec-
and was the first to use a photographic method to tion, and that its trajectory is everywhere a curved
illustrate a book. line. A century passed before Galileo showed that
Talbot patented his calotype process in 1841 and the trajectory is a paraboloid.
Taussig, Helen (Brooke) [towsig] (1899“1986) US
thereafter collected licence fees from other users of
the method, vigilantly guarding his rights by fre- physician and a pioneer in the treatment of ˜blue
quent lawsuits. His aggressive attitude retarded the babies™.
work of others, generated much ill-will, and by the Helen Taussig was born in Cambridge MA, the
1850s was stifling both amateur and commercial daughter of a Harvard professor. She attended
photography in the UK, but by 1852 the pressure of Radcliffe College and the University of California,
protest led him to relax his grip somewhat. Even so, and obtained her MD at Johns Hopkins University
he controlled for some years in the UK all ways of medical school in 1927. She joined the faculty in
making pictures by light except the daguerrotype, 1930 and took charge of the cardiac clinic of the
and it was said to be surprising that his claims did Harriet Lane Home for Invalid Children, remaining
not include the Sun as a light source. Only when in there until her retirement in 1963. She specialized
1854 he failed in his claim to cover Archer™s collo- in congenital malformations of the heart. In 1959
dion process did photography really advance. she became the first woman to be appointed a full
In 1851 Talbot founded electric flash photogra- professor at Johns Hopkins medical school.
phy, when at the Royal Institution he made a sharp Infants whose skin had a bluish hue caused by a
photograph of a rapidly rotating page of The Times lack of oxygen in the blood were termed ˜blue
by using a battery of Leyden jars, which gave an babies™ and had a restricted and short life. At the
intense spark lasting less than 10 “5 s. By 1887 Mach time there were few medical remedies for children
was using this method to photograph bullets in with congenital heart defects. Deducing that the
flight. Talbot was always interested in photome- reason for the lack of oxygen was a blockage or con-
chanical printing, and from 1858 a method he had striction of the artery connecting the heart to the
devised using a piece of gauze as a screen to break lung, Helen Taussig and Alfred Blalock (1899“1964)
up the picture into small dots gave good results for devised a procedure, in 1944, to take a branch of the
half-tone printing. As usual he was a belligerent lit- aorta that normally went to the arm and connect it
igant in this field, in part because of his erroneous to the lungs. Soon 80% of the operations performed
belief that abstract ideas are patentable and his were a success, and a modification of the procedure
view that a successor had no right to use a novel is still in use today to gain time so that the ˜blue
method to achieve a result similar to that he had baby™ can reach an age where it is strong enough to
already obtained. withstand the very major surgery needed to pro-
In his lifetime as a gentleman scholar, he had also vide a long-term solution.
prospered by the sale of photographic materials Hearing of the large numbers of babies being born
and by the sale of licences to use his methods. with heart defects in West Germany, Helen Taussig
Tartaglia, Niccolò [tah(r)talya] (c.1501“57) Italian investigated and traced a link with the drug thalido-
mathematician: found a method for solving cubic mide taken during pregnancy, widely in use there
equations. in the late 1950s and early 1960s. Returning to the
Tartaglia™s real name was probably Fontana, but USA she reported her findings to medical associa-
in the French attack on Brescia in 1512 he suffered tions and to the Food and Drug Administration,
sword wounds in the face which left him with a which had not yet approved thalidomide, and
speech defect and led to the adopted nickname thereby saved American babies from the same fate.
Tartaglia (˜stammerer™) thereafter. He taught math- For this work she was awarded the President™s
ematics in Verona and in Venice, and wrote on the Medal of Freedom, the highest civilian honour.
Taylor, Sir Geoffrey Ingram (1886“1975) British
mathematical theory of gunnery and on statics,
arithmetic, algebra and geometry. The array of physicist: discovered how dislocations allow solids
binomial coefficients now known as Pascal™s trian- to deform under shear.
gle was first published by him, as was the first trans- Taylor qualified at Cambridge, and was only
lation of Euclid into Italian and of Archimedes absent from there during the two World Wars
into Latin. By 1535 he knew a method for solving throughout his career, when he worked on aircraft
cubic equations, which he confided to Cardano design in the first, and on explosive shock waves in
under a pledge of secrecy. Cardano much improved the second. From 1923 until his retirement in 1952
and extended the method and published it (credit- he held a professorship of physics. He conducted a
ing Tartaglia) in his book Ars magna (The Great Skill, great range of research in classical physics, always
1545). Cardano found all three roots of a cubic and with originality, and chiefly on the mechanics of
suspected (correctly) that three roots always exist. fluids and solids.
Taylor, Joseph

altitude temperature Ionospheric
(km/mi) layers
Appleton layer


Heaviside layer
120/75 (E-layer)



Stratopause 0°C
Ozone layer
Tropopause “ 60°C
sea level

Layers of the atmosphere

Having done major work on fluid turbulence he sor of physics. In 1974 with his research student
applied it in meteorology, aerodynamics and the Russell A Hulse (1950“ ) a search was made for
planetary physics of Jupiter™s Great Red Spot. In new pulsars using the giant 300 m fixed radio tele-
1934 it occurred to him that metals and other crys- scope at Arecibo in Puerto Rico. These small, ultra-
talline solids might deform under shear because dense neutron stars had first been detected in 1967
faults due to planes of atoms being ˜misarranged™ by Hewish and Bell through their emission of reg-
are propagated through the crystal. These faults he ular pulses at radio wavelengths as they rotate.
named dislocations, and their presence and move- Taylor and Hulse detected a new pulsar with a
ment does indeed determine how easily most solids period between pulses of 0.05903 s. Their precise
are deformed, by comparison with the resilience of study of the slightly varying period showed that
a perfect crystal. Work on the strength and the they had detected the first binary pulsar, consisting
deformability of metals has since been much of two bodies of comparable mass and small size
shaped by these ideas. rotating about one another; the radio-emitter of the
Taylor was renowned for his experimental skill. pair taking less than 8 hrs to complete a revolution
Very much liked, he was a keen sailor and his many around the invisible companion.
inventions included a highly original anchor which In 1977 Hulse moved to Princeton to work in
became very popular for small boats. His proudest plasma physics, but Taylor continued to study the
award was the Royal Cruising Club Cup for 1927, binary pulsar. By the 1970s it was widely agreed that
won for his trip to the Lofoten Isles, with his wife the force of gravity must be transmitted by gravita-
and a friend, in his 14.6 m cutter Frolic. When he tional waves, which could also be considered as
carried out an experiment to see whether electrons massless particles, gravitons (just as light can be
are diffracted like waves the apparatus was sealed thought of as waves or as photons, depending on the
into a light-excluding box and left untouched for experimental situation). Taylor realized that the
2 weeks, so that he could go on a sailing holiday and two heavy bodies of the binary pulsar were close
return to the results. enough together to cause emission of gravitons in
Taylor, Joseph (Hooton) (1941“ ) US physicist: accord with Einstein™s prediction of 1916: and this
co-discoverer of first binary pulsar; detected gravi- should cause a slowdown in the orbital period, of 75
tons in 1978. millionths of a second per year. By 1978 Taylor could
Educated at Harvard, Taylor held a post at the report detection of a measurable change, in good
University of Massachusetts at Amherst from 1969 agreement with this figure. Taylor and Hulse shared
until 1980 when he returned to Harvard as profes- the Nobel Prize for physics in 1993.
Teisserenc de Bort, L©on Philippe

Joseph Weber (1919“2000) had made an earlier of the need for the ˜Star Wars™ initiative intended to
claim for detection of gravity waves in 1969. Weber destroy incoming nuclear missiles from the USSR.
had a US naval career before becoming professor After massive expenditure the programme con-
of electrical engineering at the University of tracted in the 1990s in the face of technical snags
Maryland. His detection system used 3 tonne alu- and the political collapse of the USSR. In so far as
minium bars, hung in pairs several hundred miles this collapse owed much to the cost of competing
apart, which responded to graviton events by with the USA in military matters, the programme
vibrating: these results were not accepted by some was arguably a success.
physicists, and Taylor™s work established gravitons In the 1990s he led a group studying the possibil-
more firmly. ity of using reflective particles placed in near-Earth
Teisserenc de Bort, L©on Philippe [taysuhrµk] orbit to reflect sunlight and so reduce global warm-
(1855“1913) French meteorologist: discovered the ing. They found that this was a feasible and cheap
stratosphere. proposition.
Tesla, Nikola [tesla] (1856“1943) Croatian“US physi-
Teisserenc de Bort worked for several years as
chief meteorologist at the Central Meteorological cist and electrical engineer: a pioneer of alter-
Bureau in Paris, before setting up his own obser- nating current and inventor of the AC induction
vatory near Versailles in 1896. In 1902, using motor.
unmanned recoverable instrumented balloons, he Tesla studied engineering at Graz and Prague
discovered that above an altitude of about 11 km before commencing work as an electrical engineer.
the temperature of the atmosphere ceases to In 1884 he emigrated to the USA, where he worked
decrease with height, and remains relatively con- for Edison before quarrelling and setting up on his
stant in this region. He named this part of the own. Soon afterwards he developed the alternating
atmosphere the stratosphere (believing that its current induction motor, eliminating the commu-
steady temperature was due to undisturbed layers, tator and sparking brushes required by DC motors.
or strata, of air), and the region below it the tropos- He also made substantial improvements in the
phere (since here the temperature varies and field of AC power transmission and generation,
mixing of the air takes place). He went on to show realizing that it could be transmitted and gener-
that the tropopause (where troposphere and ated far more efficiently than the then commonly
stratosphere meet) is much higher in the tropics. used direct current. He patented his inventions and
He had earlier shown that European weather is set up a partnership with George Westinghouse
very dependent on the atmospheric pressure at cer- (1846“1914) to commercialize them. His interest
tain centres, notably the ˜Azores high™ and the then turned to high-frequency alternating current,
˜Iceland low™ (See diagram on p.345). developing the Tesla coil, an air-core transformer
Teller, Edward (1908“ ) Hungarian“US physicist: with the primary and secondary windings in reso-
major figure in development of thermonuclear nance to produce high-frequency, high-voltage
energy. output. In 1899 he used this device to produce an
Educated in Budapest and in Germany, Teller was
one of the many scientists who left Germany in
1933. In 1935 he settled in the USA, becoming pro-
fessor of physics at George Washington University.
In 1940 he, Szilard and Wigner met with a
Government committee to discuss the possibility of
an atomic bomb; afterwards he worked with Fermi
and Szilard in Chicago on the first atomic reactor,
and then in 1943 he went to Los Alamos to work on
the first atomic (fission) bombs. By then, he and
others had considered the possibility of a fusion
bomb (H-bomb), but he discontinued this work
when the war ended in 1945. However President
Truman approved H-bomb production in 1950 and
the work was largely guided by Teller; a successful
device was exploded in 1952.
The H-bomb depends on the energy released
when light nuclei are fused to give heavier nuclei,
following ˜priming™ by a fission implosion, using a
design due to S Ulam (1909“85), to generate intense
X-rays. Much of Teller™s work in the 1950s and later
was concerned with the theory of nuclear fusion
and its use for peaceful purposes; he also supported
nuclear arms for the protective defence of the
west. He served in a series of senior posts at the
University of California from 1952 onwards, and in
the 1980s did much to convince President Reagan Nikola Tesla
Thomson, Sir Charles Wyville

electric spark 41 m/135 ft long, and claimed to illu- for physiology or medicine in 1951 ˜for his discover-
minate 200 lights over a distance of 40 km/25 mi ies concerning yellow fever and how to combat it™.
without intervening wires by using the Earth as a He was fortunate to survive yellow fever him-
transmitting oscillator. He was increasingly inter- self in 1929, afterwards having the advantage of
ested in transmitting power over large distances immunity.
Theophrastus [theeohfrastuhs] (c.372“c.287 bc)
without wires; he became an eccentric recluse after
1892. The SI unit of magnetic flux density, the tesla Greek philosopher and botanist: often described as
(T), is named after him. ˜the father of botany™.
Today, as Tesla foresaw, alternating current and Born in Lesbos, Theophrastus studied with Plato
induction motors remain dominant in the power in Athens and then became Aristotle™s assistant,
industry. friend and successor as head of the Lyceum in
Thales (of Miletos) [thayleez] (c.625“c.550 bc) 335 bc. The school did well under him, and may
Ionian (Greek) merchant and philosopher; an early have had 2000 students; he secured botanical infor-
geometer; pioneer seeker of general physical prin- mation from their home areas to add to his own
ciples underlying nature. observations. He wrote on many subjects, but his
Thales was born in Miletos (in modern Turkey) most important surviving books are on botany. He
˜the most go-ahead town in the Greek world™. described over 500 plant species and understood
Thales was probably a successful merchant who vis- the relation between fruit, flower and seed, and the
ited Egypt and there learned something of Egyptian differences between monocotyledons and dicotyle-
geometry; but little is firmly known of his life and dons and between angiosperms (flowering plants)
achievements, despite his high reputation, and and gymnosperms (cone-bearers). Plant propaga-
some of the many accounts of his skill lack credi- tion methods, and the effect on growth of soil and
bility. But it is certainly possible that he developed climate, are also accurately described by him. His
some general theorems in geometry, understood ideas were usually sound, although he believed in
similar triangles and was able to find the distance spontaneous generation, in accord with the views
of a ship from shore and the height of a building of his time.
from its shadow. Such deductive mathematical His classificatory interests extended to people;
arguments were systematized 250 years later by his best known book, Characters, is a series of
Euclid. Thales was said also to be aware of the lode- humorous essays dealing with ˜city types™. Each
stone™s magnetic attraction for iron. essay first defines an attribute and then illustrates
According to Aristotle, Thales believed that the from life the conduct of the Coward, the Mean Man,
Earth and all things on it had once been water and the Spreader of False Rumours, and so on. The
had changed by some natural process (akin to the result provides much information on city life in
silting-up of the Nile delta); and that the Earth as a Athens in Theophrastus™s time.
Thompson, Benjamin, Count Rumford see
whole was a flat disc floating in water. He offered
natural (and not supernatural) explanations for
Thomson, Sir Charles Wyville (1830“82) British
phenomena such as earthquakes, and he attempted
to derive theories from observed facts. He was thus marine biologist and oceanographer: postulated
a pioneer of later Greek science, and his attitudes the existence of a mid-Atlantic ridge and of oceanic
are still with us. Later Greek thinkers gave him the circulation.
highest place in their lists of wise men; and it can Educated at the University of Edinburgh, Thomson
be argued that he is the earliest ˜scientific™ thinker held a number of academic posts in Scotland and
we can name. Ireland before being appointed professor of natural
Theiler, Max [tiyler] (1899“1972) South African“US history at Edinburgh in 1870. He took part in sev-
virologist: developed 17D vaccine against yellow eral deep-sea expeditions, leading the 5-year cir-
fever. cumnavigational Challenger expedition of 1872“6, a
Theiler studied medicine in South Africa and in landmark in marine exploration which resulted in
London, and joined the staff of the Rockefeller the discovery of 4717 new marine species.
Foundation in New York in 1930. Before that he had Thomson disproved two accepted beliefs: that the
shown that yellow fever was certainly due to a oceans were lifeless below 300 fathoms (about
virus, which could be cultured in mice, and he went 550 m); and that a fairly constant temperature of
on to show that by transmitting it from mouse to about 4°C existed at these depths. He found many
mouse many times, a safe and standardized vaccine animals by dredging at depth, and diverse temper-
could be mass-produced. On injection into human atures at similar submarine depths in different
patients this induces yellow fever infection in an regions. The expedition also showed that a clay
extremely mild form, with the benefit that it is fol- bottom is usual at great depths and that nodules of
lowed by immunity from the full disease because nearly pure manganese dioxide (MnO2) are found
antibodies have been generated in the blood. This on the sea-floor.
vaccine (17D) effectively eliminated yellow fever as All this work revitalized oceanography. On the
a major human disease and completed that work basis of temperature measurements Thomson pos-
begun by Reed, who had shown in 1901 that the dis- tulated the presence of oceanic circulation and the
ease was probably due to a virus and was transmitted existence of a mid-Atlantic ridge, but the latter was
through mosquito bites. Theiler won the Nobel Prize not confirmed until 1925.
Thomson, Sir George Paget

Thomson, Sir George Paget (1892“1975) British J J Thomson was a bookseller™s son who first stud-
physicist: discovered experimentally the interfer- ied at Owens College (later Manchester University),
ence (diffraction) of electrons by atoms in crystals. hoping to become an engineer. Poverty caused by
G P Thomson, the only son of J J Thomson, had an his father™s death in 1872 led him to study math-
outstanding college career. He survived the first ematics, physics and chemistry instead, as he could
year of the First World War in the infantry and in not afford the charge then made to become an
1915 was attached to the Royal Flying Corps to work apprentice engineer. He did well and won a scholar-
on problems of aircraft stability. In 1919 he returned ship to Trinity College, Cambridge (1876). As a
to Cambridge, working first in his father™s field of mathematician he graduated Second Wrangler
positive rays. He then went to the University of (1880), and subsequently became a Fellow of Trinity
Aberdeen, being appointed to a professorship there College, Cavendish Professor (1884“1919, succeed-
at the age of 30. With his student Alex Reid he ing Rayleigh) and Master of Trinity in 1918. In
observed (in 1927) electron diffraction of electrons modern terms ˜JJ™ was an experimentalist; but his
passing through thin celluloid film or metal foil, hands were clumsy and his best work was actually
recorded on photographic plates as concentric performed by assistants. He was exceptionally well-
rings of varying intensity about the incident beam. liked.
While not undertaken for that purpose they recog- Thomson had carried out an excellent mathe-
nized the experiment as confirming Broglie™s pos- matical analysis of vortex rings in 1883 and specu-
tulate of wave-particle duality. Thomson received lation that atoms might be vortex rings in the
the 1937 Nobel Prize for physics jointly with imagined electromagnetic ˜ether™ led him to inves-
Davisson, who had also achieved diffraction of tigate cathode rays (the electrical discharge emit-
electrons but by use of a nickel crystal rather than ted from an electrode under high fields in a gas at
a metal foil. low pressure). Several German physicists believed
In 1930 Thomson moved to Imperial College, that cathode rays were waves, and Hertz had tried
London. By 1939 he was aware of the possibility of a to show that they could not be particles, because
uranium fission bomb being developed, very possi- in his experiments the cathode rays were not
bly by Germany. During the Second World War he deflected by an electric field. However, Thomson
chaired the Maud Committee, advising the British repeated the experiment in a better vacuum, in
Government on the atomic bomb, and in July 1941 which there was no polarizable air to mask the elec-
reported that such a bomb could be made using tric field, and demonstrated that electric fields
separated uranium-235. The co-ordinating role on would deflect cathode rays (1897). Having shown
the bomb project then passed to Chadwick, while that the rays were made up of negatively charged
Thomson became scientific advisor to Canada, and particles, he proceeded to use their deflection
then in 1943 to the Air Ministry in Britain. After the under combined electric and magnetic fields to
war, in 1952, he returned to Cambridge as Master of find the charge to mass ratio (e/m) of the particles,
Corpus Christi College. Always known as ˜GP™, he which did not vary from one cathode material to
had considerable intuition in physics. Widely liked another. In April 1897 he revealed this discovery of
and good company, his life-long enthusiasms were a new particle. Developing this classic series of
sailing and model boats, which he made himself, experiments, Thomson then measured the charge e
including their armament; he was particularly by allowing the particles to strike water droplets
pleased with his working model submarines. and observing the droplet™s rate of fall in an electric
Thomson, Sir Joseph John (1856“1940) British field (see Millikan). He obtained the same value as
physicist: discovered the electron. the charge on a hydrogen atom, but using both
results he found a mass m for the new particle
about 1000 times lighter than hydrogen. Shortly
afterwards Thomson™s particle was named the
˜electron™ by Stoney. Its discovery opened the way
for the study of atomic structure by Rutherford,
who succeeded him as Cavendish Professor. His
device for measuring e/m is essentially the cathode
ray oscillograph, so much used afterwards in both
research and in television receivers.
Thomson also examined E Goldstein™s (1850“
1930) positive rays obtained when a perforated
anode was used in the discharge tube, whose
nature depended on the gas in the discharge tube;
the cathode rays were the same whatever gas was
present, and in 1912 Thomson showed how to use
positive rays to separate atoms of different mass.
This was done by deflecting the positive rays in
electric and magnetic fields (a method now called
mass spectrometry). The method allowed him to
J J Thomson aged 22, about the time he took his first
discover that neon had two isotopes, neon-20 and
Thomson, William, 1st Baron Kelvin

fluorescent screen




high voltage

J J Thomson™s apparatus for finding the ratio of charge to mass (e/m) for the electron. In the evacuated tube, a high volt-
age applied to the cathode and anode causes cathode rays (a stream of electrons) to be emitted from the cathode. A nar-
row beam is selected by two small holes, and forms a bright spot on the screen. The beam is deflected by a magnetic
field, but can be restored to its normal position by an electric field applied to the two horizontal plates. From the field
strengths, e/m can be calculated.

neon-22, and Aston then developed the technique. the transmission of electrostatic force and heat
Thomson was prone to attack some chemical prob- flow in a uniform solid (Maxwell later brought this
lems when he felt (as in 1923) that physics was into his full theory of electromagnetism). Thomson
becoming too non-classical for his taste. His chemi- reorganized the theory of magnetism, developing
cal knowledge and instincts were limited, and such Faraday™s ideas, and introduced the ideas of mag-
ventures were rather unfruitful “ in contrast to his netic susceptibility and permeability, and of the
early work on positive rays which, via Aston and total energy of a magnetic system. Thomson was
mass spectrometry, proved so valuable to chemists. not only a theoretician but put his knowledge to
Thomson also showed that electrons are emitted practical effect, showing that low voltages were
from a hot, negatively charged metal wire, and better than high ones for the transmission of sig-
from a negatively charged zinc plate if it is exposed nals along submarine cables and inventing the
to ultraviolet radiation. mirror galvanometer for the detection of the result-
Thomson received the 1906 Nobel Prize for physics
for research on conduction through gases. One of his
achievements was to have built up the Cavendish
Laboratory as the foremost in experimental physics,
with seven of his research assistants subsequently
winning Nobel Prizes. To his great pleasure his son
(G P Thomson) was also a Nobel Prize winner, for
demonstrating that the electron possessed both par-
ticle-like and wave-like behaviour.
Thomson, William, 1st Baron Kelvin (of Largs)
(1824“1907) British physicist and electrical engi-
neer: a pioneer of thermodynamics and electro-
magnetic theory; he directed the first successful
project for a transatlantic cable telegraph.
Thomson™s father had been a farm labourer who
became professor of mathematics at Belfast and
from 1832 at Glasgow. Two of his children became
distinguished physicists and another did well in
medicine. Young William studied science in Glasgow
from the age of 10, and later was sent to Cambridge.
He graduated when he was 21 and went to Paris to
work on heat with Regnault, returning the next
year to become professor of natural philosophy (ie
physics) at Glasgow. He held the job for 53 years.
While still an undergraduate he gave a math-
ematical demonstration of the analogy between William Thomson (later Lord Kelvin) aged 22.
Panel: The Internet and international scientific collaboration

THE INTERNET AND INTERNATIONAL network, being extensively used to allow academic
SCIENTIFIC COLLABORATION groups to communicate discoveries and discuss
ideas. Throughout this period, it was the scientific
Although the Internet and the World Wide Web have community that was both developing the technology,
become synonymous with global retailing and 'e- and constituting its primary user, benefiting through
commerce', both were originally developed in being able to work together on projects (including
response to the needs of scientists to share scientific the Internet development) regardless of geographical
data and collaborate better. Throughout most of its separation. As the number of computers connected
nearly forty-year history, the Internet has not only to the Internet mushroomed during the late 1970s, it
been developed by computer scientists, but its evolu- became necessary to find a way of maintaining the
tion has been heavily shaped by collaboration on 'address book' of names of the networked comput-
science projects. ers. This resulted in the development of the Domain
The Internet has its origins in work on packet- Name System (DNS) by Paul Mockapetris of the
switched networks at the Defense Advanced University of California, which is how your PC knows
Research Projects Agency (DARPA) in the US in the which computer on the network to connect to when
early 1960s, when the idea of connecting a number you type 'www.yahoo.com', or any other website
of remote computers together in a 'network' was first name. At the same time new and improved communi-
seriously considered. Contrary to a widespread myth, cations hardware in the form of 'gateways' and
this research was never initiated by military require- 'routers' were developed to handle the new network
ments for robust communications networks that traffic, which was by then growing at an exponential
could withstand nuclear war, although later on it rate.
became necessary to ensure that the Internet was By 1985, the Internet was well established as a
robust enough to continue functioning even when technology supporting communication between the
large portions of the underlying physical network had scientific and R&D communities, and was beginning
failed. In 1965, two computers in Massachusetts and to spread to other communities for daily communica-
California were connected via telephone line, making tion. At this time, communication was already largely
the first wide-area network (WAN) ever built. Two by email and the ability to access files on one com-
years later, after the realization that three separate puter from another was widely used, but the Internet
research groups at MIT in Cambridge, MA, RAND in lacked the graphical interfaces that we are familiar
Santa Monica, CA, and the National Physical with today. The widespread use of the Internet by the
Laboratory in the UK were all working on similar non-academic community required the development
ideas, a proposal was made to build ARPANET, a of the World Wide Web (WWW), first proposed in
national (and later international) network connecting 1989 by the British computer scientist Tim Berners-
many academic institutions and research organiza- Lee at CERN, Switzerland. Even so, the WWW was
tions. By the end of 1969 the first four sites were con- initially envisioned principally as a means of helping
nected to the ARPANET, at UCLA, Stanford, UC Santa CERN's large-scale physics projects organize their
Barbara and the University of Utah, and what was documentation, rather than as a way of commercial-
eventually to become the Internet had been born. The izing access to the net. In the space of a few months
first international nodes, NORSAR in Norway and in 1990, Berners-Lee and his colleague Robert
University College, London, were added in 1973. Cailliau developed two of the main components of
The Internet was more than just an extension of the web, namely the hypertext transfer protocol
ARPANET however “ the essential difference being (HTTP) and hypertext mark-up language (HTML).
that the Internet was conceived as a network made HTTP provides a means of accessing files, whilst
up of multiple different networks, which could be of HTML is a format for displaying and linking docu-
different architectures and design. Thus the Internet ments. Berners-Lee also developed the concept of the
could include radio and satellite networks, as well as Universal Resource Locator (URL), through which
different types of telephone-based networks. This every document or 'page' on the web has a distinct
required the development of better packet-switching and unique 'address'.
technology, that could tolerate 'lost' packets, radio The final technical innovation necessary for the
interference and noise, etc. In order to accomplish popular success of the web was the development in
this, the Transmission Control Protocol/Internet 1993, by Marc Andreessen at the National Center for
Protocol (TCP/IP) was developed by Bob Kahn at Supercomputing Applications at the University of
DARPA and Vince Cerf at Stanford University in the Illinois, of Mosaic, the first widely used 'browser'. A
early 1970s. Around the same time, in 1972, elec- browser is a software program used for navigating
tronic mail (email) was first developed, and quickly the web easily and for viewing web pages including
became the first 'hot' application for the new graphics; the subsequent development of the first

Thomson, William, 1st Baron Kelvin

commercial browser, Netscape, made Andreessen everyday benefits. Over 300 million people (in the
the first Internet billionaire. year 2000) regularly used the Internet for communi-
Through the vastly improved ease of access to cating, finding information, and buying products and
documents offered by the WWW technologies, not services. E-commerce in 2000 was worth well over
only has the Internet become standard communica- $100 billion per year; a figure which is expected to
tions technology for the world-wide scientific com- grow ten-fold in the next few years, to reach 20% of
munity, enabling international collaboration on global gross domestic product.
research hitherto impossible, but also it has brought

ing small currents. He directed work on the first 1848 an ˜absolute™ scale of temperature now known
successful transatlantic cable (there had been two as the Kelvin or thermodynamic scale; it is inde-
previous attempts), which became operational in pendent of particular substances, but corresponds
1866, bringing him considerable personal wealth. practically to the Celsius scale with 273.16 K as the
In 1892 he was made a baron, and chose his title triple point of water, 0°C. The SI unit of tempera-
from a small river, the Kelvin, passing through the ture is the kelvin (K). Independently of Clausius he
university. He was a major figure in the creation of formulated the second law of thermodynamics,
the Institute of Electrical Engineers. He liked sail- which states that heat cannot flow spontaneously
ing and bought ˜a schooner of 126 — 106 g™ (ie 126 t), from a colder to a hotter body. He worked with
which prompted him to develop navigational instru- Joule on the relation of heat and work (the first law
ments; and his large Glasgow house was among the of thermodynamics), and also with him found the
first to be lit by electricity (in 1881). Joule“Thomson effect. This is the drop in tempera-
As a young man Thomson discovered G Green™s ture shown by most gases when they emerge from
work, then hardly known, and publicized it; he a fine nozzle, as a result of the work done to pull the
found that Green™s and his own theorems gave mutually attracting gas molecules apart, and it is
valuable mathematical methods for attacking the basis of modern methods for cooling gases for
problems in electricity and in heat. liquefaction. Thomson worked on the theory of the
Thomson did much to develop heat theory. He cooling of a hot solid sphere and applied his theory
heard of Carnot™s work when he was in Paris, but it to calculate ages for the Earth and the Sun. He rec-
was three years before he secured his paper; he ognized that his method assumed that no continu-
then made its ideas widely known, and used and ing heat supply was present: his results were about
developed them further. Thomson proposed in 10 times lower than present values, which now take

The Agamemnon laying the first completed transatlantic telegraph cable in 1858: it survived for three months. A durable
cable was laid in 1865.
Tinbergen, Nikolaas

into account heat due to radioactivity, which was
not discovered until many years after Thomson™s
early work.
Thomson was an unusual scientist; his energy,
enthusiasm and talent made him dominate British
physics in the later 19th-c and he did much to move
the focus of physics from Europe to Britain. He was
always generous with ideas and in giving credit to
others. His productivity was vast; 661 papers, many
books and patents, covering the whole of physics
(no-one since has ranged so widely) with sundry
excursions into other sciences. He had some oddi-
ties, of course. He detested vector methods and gave
himself much mathematical toil in avoiding them.
He did not normally work on one problem for more
than a month, and his results were worked out in
green pocket books from which he tore sheets for
publication. After his first wife died in 1870 he con-
tinued to have a great flow of ideas in physics, but
he lost the ability to select good ideas from bad, and S C C Ting
he pursued some strange notions (like the theory
of the ether; and his opposition to the admission of Ting conducted an experiment at the Brookhaven
women to Cambridge). He was probably the first National Laboratory synchrotron in which protons
scientist to become wealthy through science. were directed onto a beryllium target, and long-
Tinbergen, Nikolaas [tinbergen] (1907“88) Dutch lived product particles were observed (1974). This
ethologist: a pioneer in study of animal behaviour. newly discovered particle was named the J particle;
Tinbergen graduated in zoology at Leiden, and it was observed at the same time and indepen-
afterwards taught there, except for 3 years in the dently by B Richter at Stanford, who called it the
Second World War spent in a hostage camp in occu- psi particle. It is now known as the J/psi particle.
pied Holland. In 1947 he moved to Oxford and Soon, other related particles of the J/psi family were
developed there his work on animal behaviour. The detected, and Ting and Richter shared the Nobel
emphasis of this was to examine the patterns of Prize for physics in 1976.
Tiselius, Arne (Wilhelm Kaurin) [tisayleeus]
behaviour shown by animals in natural conditions
as well as in the laboratory; it included work on (1902“71) Swedish physical biochemist: developed
digger wasps, arctic foxes, seals, sea birds and technique of electrophoresis for separating proteins.
snails. His now-classic studies of the social habits of Tiselius was a pupil and then assistant to Sved-
herring gulls and the mating of sticklebacks berg, and like him had his career in Uppsala, work-
showed that key elements of behaviour follow a ing mainly on proteins. Since these carry electric
stereotyped pattern and can depend largely on par- charges, they can be made to migrate in solution by
ticular features. For example, the gull chick pecks applying an electric field. Tiselius developed this
for food at the parent™s beak largely in response to method (electrophoresis) to separate proteins, and
a red spot on the latter. Also in these gulls, the method has since been widely used. He showed
Tinbergen found that aggression between males is that blood serum proteins can be separated into
shown not only by calls but also by gestures, which four groups of related proteins; they are the albu-
mens and the ±-, β- and γ-globulins. He was awarded
in part seem designed to avoid actual fighting and
injury. His wide-ranging work included study of a Nobel Prize in 1948.
Todd, Alexander Robertus, Lord (1907“97) British
learning behaviour, animal camouflage, instinct,
and autism and aggression in human beings. He organic chemist: achieved synthesis of important
shared a Nobel Prize in 1973. His elder brother Jan natural products, including co-enzymes, ATP and
also shared a Nobel-style Prize, the first awarded by structural units of DNA.
the Swedish National Bank for economics, in 1969. As a schoolboy in Glasgow, Todd did well in all
Ting, Samuel Chao Chung (1936“ ) US physicist: subjects except art (he was teased about the inap-
discovered the J/psi particle. propriateness of his initials) but his enthusiasm
Ting had an unusual upbringing, he was born in was chemistry, which he studied in Glasgow and
the USA but educated in China and Taiwan, and later in Frankfurt. In Oxford with Robinson he
finally at the University of Michigan (1956“62). His worked on synthesis of the anthocyanins, which
work in elementary-particle physics began at the colour plant petals and fruits, and his chemical
European Organization for Nuclear Research in interests focused thereafter on organic natural
Geneva (CERN) and Columbia University, where he products. Next in London at the Lister Institute he
became an associate professor at 29. He also led a devised syntheses of tocopherol (vitamin E) and of
research group at DESY, the German synchrotron thiamin (vitamin B1): the latter became the preferred
project in Hamburg, and from 1967 worked at commercial route. He also worked on the consti-
Massachusetts Institute of Technology. tuents of cannabis resin, ingenuously bringing
Townes, Charles Hard

through Customs from India some 2 kg of it and the name also honours (through his initials)
donated by the Indian police. When the results of Percival Lowell, who predicted its existence.
Tomonaga, Sin-Itiro [tomonahga] (1906“79)
this work were published this importation dis-
mayed the Drugs Branch of the Home Office, who Japanese theoretical physicist: a founder of quan-
also insisted that in future 25 copies of such publi- tum electrodynamics (QED).
cations be sent to the Bureau of Drugs and Indecent Tomonaga graduated in physics at Kyoto Univer-
Publications. In 1938 he became professor at sity and studied with Heisenberg at Leipzig before
Manchester, where he built up a team of highly becoming professor of physics at Tokyo (1941) and
effective co-workers, ˜the Toddlers™. In the Second then president of the university (1956).
World War he worked on war gases, which were Like others, Tomonaga started to develop a rela-
never used in action. Most of the Toddlers joined him tivistic theory of the quantum mechanics of an
when he moved to Cambridge in 1944. Research electron interacting with a photon (1941“3). During
there concerned the colouring matters of aphids; the Second World War, he, Feynman and Schwinger
the relation of vitamins to the co-enzymes into were unaware of each other™s work, and it was not
which they are converted in the body; and the suc- until 1947 that it was realized that all three had
cessful synthesis of ATP, which is the living cell™s arrived independently at solutions to the problem
energy carrier responsible for the conversion of of linking special relativity with quantum physics,
nutrients into energy-using activity of any kind in solutions which were shown to be identical by
plants and animals. His most important work was Dyson. Tomonaga realized the value of a theory
on the nucleic acids (DNA and RNA) where he and that could describe high-energy subatomic particles
his team devised methods of making the units and he was responsible for the idea that two parti-
(nucleotides) from which the nucleic acids were cles interact by exchanging a third virtual particle
later synthesized. This laid essential groundwork between them. The interaction is then like the
for the results of Crick and Watson in 1953 which momentum exchange when one rugby player
revealed the chemical basis of genetics and so passes the ball to another. The resulting theory is
created modern ˜molecular biology™. called quantum electrodynamics (QED) and for its
He went on to attack the problem of the highly discovery Feynman, Schwinger and Tomonaga
complex and unusual structure of vitamin B12, shared the 1965 Nobel Prize for physics.
Torricelli, Evangelista [torichelee] (1608“47) Italian
which was solved in 1956 by linking Todd™s chemi-
cal results with Hodgkin™s crystallographic studies physicist: inventor of the mercury barometer and
of the vitamin. Todd won an unshared Nobel Prize discoverer of atmospheric pressure.
for chemistry in 1957. Thereafter, while presiding An orphan, Torricelli was educated by the Jesuits
at Cambridge over Britain™s dominant university and by B Castelli (1578“1643), for whom he worked
chemical laboratory, Todd was increasingly involved on the dynamics of falling bodies. This led to his
in advice to governments and associated public being appointed assistant to Galileo, whom he sub-
commitments. He was made a Baron in 1962, became sequently succeeded as mathematician to the court
Master of Christ™s College in 1963, President of the of Tuscany.
Royal Society in 1975 and a member of the Order of Torricelli™s interests covered pure mathematics
Merit in 1977. A man of strong opinions (often, but and experimental physics; he worked on conic sec-
not always, found to be right) he was known to tions and other curves, deriving the area of the
some as ˜the Lord Todd Almighty™. cycloid. He is best remembered, however, for his
Tombaugh, Clyde William [tombow] (1906“97) US discovery of atmospheric pressure and for his
astronomer: discovered Pluto. invention, in 1643, of the mercury barometer. This
Too poor to attend college,Tombaugh was a keen appears to have come about from an attempt to
amateur astronomer and built his own 9 in (23 cm) solve the problem of why water could not be
telescope. He was appointed as an assistant at the pumped out of a well more than 33 feet (≈ 10 m)
Lowell Observatory, Arizona, in 1929, and took over deep. Deducing that the reason was that the atmos-
Lowell™s search for a trans-Neptunian planet; Lowell phere possessed weight and therefore exerted a
had died in 1916. After repeatedly photographing pressure, he set about verifying the idea by sealing
the sky along the plane of the ecliptic, and checking a glass tube at one end, filling it with mercury and
for differences between successive photographs with inverting it with the open end in a dish of mercury.
a blink comparator, Tombaugh finally announced He found that the height of the mercury column
the finding of the new planet (Pluto) on 13 March fell to about 760 mm, and reasoned that a vacuum
1930. Afterwards he continued the search for possi- was formed above it; the weight of the column was
ble further planets, but although he discovered being balanced by the weight of the atmosphere. He
over 3000 asteroids, he found no other planets. later noticed the small daily variations in the
Pluto, the outermost of the planets, is in several height of the column, which he related to changes
ways unusual: its orbit is highly eccentric and is in the weather.
Tour, Charles Cagniard de la see Cagniard de la
tilted, it is much smaller than the other outer plan-
ets and it has a relatively large satellite, Charon,
Townes, Charles Hard (1915“ ) US physicist: dis-
with which it is locked in synchronous rotation,
each keeping the same side facing the other. Pluto covered the theory of the maser and produced the
is named after the Greek god of the underworld, first working examples.
Trumpler, Robert Julius

Townes was the son of a lawyer and he completed to the construction of oscillators and amplifiers
his education in 1939, having attended Furman based on the maser“laser principle™.
Trumpler, Robert Julius (1886“1956) Swiss“US
University, Duke University and California Institute
of Technology. He began work at the Bell Telephone astronomer: discovered interstellar light absorption.
Laboratories and spent the war years developing Trumpler was educated at Zürich and Göttingen.
radar-assisted bomb sights. Radar uses microwave He moved to the USA in 1915, spending most of his
radiation, with a frequency between that of radio career at the Lick Observatory in California. In
and infrared light. In 1947 he joined the physics 1930, while measuring the distance and size of over
department at Columbia University. He spent 300 open star clusters, Trumpler discovered that
1961“7 at Massachusetts Institute of Technology the more distant ones generally appeared to be
and then became a professor at the University of larger than the nearer ones. Since there was no
California at Berkeley. apparent reason for this, he assumed that he was
Beginning as early as 1945, Townes had studied observing the result of the interstellar absorption
the absorption and emission of photons when a of light by dust grains, and measured the effect to
molecule goes from one configuration to another. be a decrease in brightness of approximately 20%
This involves very precise photon frequencies for every 1000 light years travelled by the starlight.


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