ńňđ. 14
(âńĺăî 21)



theory of gravitation, that any two bodies of mass whose viscosity is independent of the rate of shear
m1, m2 at a distance d apart, attract each other with or the velocity gradient. Colloids and some other
a force F: solutions form non-Newtonian fluids. Newton’s
F = G m1m2/d2 law of cooling states that the rate at which a body
where G is a universal constant, was developed by loses heat to its surroundings is proportional to the
Newton from his original work on the Moon’s temperature difference between the body and its
motion of 1665. It may well be correct (as Newton’s surroundings. It is empirical, and applies only to
niece maintained) that the idea stemmed from see- small differences of temperature, and to forced
ing an apple fall from a tree beside his Woolsthorpe convection.
home. Three centuries ahead of the technology he Newton exerted a unique and profound influence
showed that the escape speed s of an artificial satel- on science and thought. As a mathematician he dis-
lite from a planet of mass m and radius r is given by covered the binomial theorem and the calculus;
s = (2Gm/r) . At speeds less than this, the projected the latter, together with his law of universal gravi-
satellite will return to the planetary surface. tation are the peaks of his achievement and the
Newton published another celebrated treatise, basis of his colossal stature. His work established
the Opticks of 1704, which was an organized and the scientific method and placed physics on a new
coherent account of the behaviour of light. Based course, giving mathematical expression to physical
on his own ingenious experimental work, it pro- phenomena and permanently altering modern
posed a corpuscular theory of light but added ideas thought.
of periodicity (which were missing even in Hooke’s Einstein wrote of him: ‘Nature was to him an
and Huygens’s wave theory). Such phenomena as open book, whose letters he could read without
refraction of light by a prism (with the production effort…. In one person he combined the experi-
of colours by dispersion) and Newton’s rings of menter, the theorist, the mechanic and, not least
coloured light, about the point of contact between the artist in exposition. He stands before us strong,
a lens and mirror, were considered. Also named certain and alone: his joy in creation and his
after him is the Newtonian telescope, which used minute precision are evident in every word and
every figure.’
Newton’s view of himself at the end of his life has
a different emphasis: ‘I do not know what I may
appear to the world; but to myself I seem to have
been only like a boy playing on the seashore, and
diverting myself in now and then finding a
smoother pebble or a prettier shell than ordinary,
whilst the great ocean of truth lay all undiscovered
before me.’ Some have suggested this was conven-
tional false modesty.
His birthplace, Woolsthorpe Manor, is main-
tained by the National Trust.
Nicholson, William (1753–1815) British chemist:
discovered electrolysis.
Nicholson had a wide-ranging career, being vari-
ously an agent for the East India Company and for
Josiah Wedgwood (1730–95) the pottery manufac-
turer, a schoolmaster, a patent agent and a water-
Newton's telescope, the first reflector. Made entirely by
works engineer.
him and about 6 inches long; it was presented to the
Within months of Volta’s invention of the first
Royal Society in 1671. The two crowns are a single decora-
electric battery, Nicholson had built the first one in
tion on a building over 300 ft distant, as seen (Fig 2)
Britain. Soon afterwards he discovered that, if the
through Newton's reflector (giving 38Ă—), and (in Fig 3)
leads from it were immersed in water, bubbles of
with colour fringes through a 25-inch long refracting
hydrogen and oxygen were produced. His discovery
Nobel, Alfred Bernhard

of the phenomenon of electrolysis was followed up with his brother Claude to record the image formed
by Davy, who was to become a pioneer of the new in a camera obscura by chemical means, assisted by
field of electrochemistry. Nicholson also invented Joseph’s son Isidore. By 1816 he had some success,
a hydrometer, and both wrote and translated a using a paper sensitized by impregnation with
number of of well-respected chemical textbooks. silver chloride and an exposure time of about an
Nicol, William (1768–1851) British geologist and hour. The resulting image showed light and shade
physicist: inventor of the Nicol prism. reversed and had to be viewed by candlelight to
Nicol lectured in natural philosophy at the Uni- avoid further darkening. Even so, this result was an
versity of Edinburgh. In 1828 he invented the Nicol advance on Wedgwood’s and was some years
prism, which utilizes the doubly refracting prop- ahead of comparable results by Daguerre and
erty of Iceland spar and proved invaluable in the Talbot. By the 1820s Niépce turned from silver salts
investigation of polarized light. to the oddly named bitumen of Judaea as his light-
However, this usage was much delayed; his in- sensitive material. A coating of this on a glass or
vention did not appear in print until 1831 and then metal plate is hardened and made insoluble by
only in a little-read book on fossil woods. Sorby light, and he used this to obtain photocopies by
knew of Nicol’s invention and by 1861 applied it to superposing an engraving, made transparent by
the study of mineral structure, and so made the oiling, on a glass plate coated with the bitumen.
polarizing microscope an essential instrument in The first photograph in the modern sense was
petrology and later in metallurgy. Organic probably made by Niépce in 1826 or 1827, using a
chemists also applied it in polarimeters, to mea- bitumen-coated pewter plate in a camera obscura,
sure the polarization of solutions. More recently, and showed the view from his workroom window.
Land’s invention of Polaroid® has largely replaced The image was fixed by dissolving away the unhard-
the Nicol prism, which was so valuable for a cen- ened bitumen in lavender oil. Niépce met Daguerre
tury. in 1826 and in 1829 a partnership with him to
Nicol also developed the technique of grinding exploit ‘heliography’ was agreed and a contract
rock specimens, cemented to a glass slide, to signed. Niépce’s cameras are the earliest known and
extreme thinness so that they could be examined include a focusing tube and iris diaphragm for the
by transmitted light; this major advance in petrol- lens, and bellows to adjust the length. Hoping to con-
ogy also did not appear until 1831. vert his result into a printing-plate, Niépce began in
Nicolle, Charles (Jules Henri) [neekol] (1866– 1829 to use a silvered copper plate as base and black-
1936) French microbiologist: identified the louse as ened this with iodine vapour to improve its contrast.
the vector of typhus. In this way, rather indirectly, he was led to a satis-
Nicolle became director of the Pasteur Institute factory photosensitive surface of silver iodide, which
in Tunis in 1902 and soon began to study the epi- his partner Daguerre later found by chance in 1835
demic typhus fever there. The typhus fevers are a could be developed with mercury vapour and in
group of related diseases, long-known and world- 1837 fixed with a solution of common salt: this gave
wide, with a mortality of 10–70%; their causal the ‘daguerrotypes’ which soon became famous. But
pathogens are the rickettsias, which lie between Niépce had died in 1833 before this success, and his
bacteria and viruses in size and type. Nicolle’s suc- efforts in 1827 and later to interest King George IV
cess in combating typhus began when he noted and the Royal Society in his ideas had failed, largely
that the victims infected others before they entered because he kept his methods secret. It was left to
hospital but did not infect others when in hospital. Daguerre, combining his improvements in method
He deduced that the path of infection was broken with his skill as a publicist, to first achieve real
when they were separated from their clothing and renown, and to Talbot and his friend John Herschel
cleaned, and guessed that the body louse was the to devise a widely useable system.
Nobel, Alfred Bernhard [nohbel] (1833–96)
vector. Experiments with monkeys proved his
guess to be correct, and showed that the louse is Swedish chemist: inventor of dynamite.
only infective after taking blood from a victim and Nobel’s father was an inventive engineer who
that it spread infection through its faeces. After travelled widely. The family moved to Russia in
this work (1909) vigorous attack on the lice has led 1842 (where Nobel’s father was supervising the
to effective control. Nicolle’s later work on typhus manufacture of a submarine mine he had devised)
showed that antibodies exist in recovered patients; and Alfred was educated there by tutors; his studies
and also after influenza and measles. He also dis- included chemistry and five modern languages. He
covered the ‘carrier’ state, important in immunol- went in 1850 to study chemistry in Paris, and then
ogy. Other rickettsial diseases (eg Rocky Mountain travelled in Europe before visiting the USA to work
fever) are carried by ticks and by mites. Nicolle was with J Ericsson (1803–99), the Swedish–American
awarded a Nobel Prize in 1928. inventor of the marine screw propeller. He
Niépce, Joseph Nicéphore [nyeps] (1765–1833) returned to Russia and then to Sweden in 1859. He
French inventor of photography. was much interested, like his father, in the use of
Although several individuals made major contri- explosives in civil engineering, especially in the
butions to black-and-white photography as we now developing US market. In 1865 he began to
know it, NiĂ©pce has the best claim to be regarded as manufacture glyceryl trinitrate (‘nitroglycerin’,
the first photographer. From 1792 he attempted discovered in 1847 by A Sobrero (1812–88)), but the
Noddack, Ida

dangerously explosive liquid caused accidents in allowed women to matriculate, so she returned
handling; his factory blew up the same year with there in 1904. She studied at Erlangen under Paul
five deaths (including that of his brother Emil). In Gordan (1837–1912), a family friend, and gained a
1866 he found that it was a safe high explosive if PhD summa cum laude in 1907 for a dissertation on
absorbed in kieselguhr; the mixture was sold in algebraic invariants. Paid employment was impossi-
waxed card tubes as ‘dynamite’. In 1875 he ble and from 1908–15 she occasionally lectured at
invented blasting gelatine or gelignite (nitroglyc- the university for her father. In 1911 Ernst Fischer
erin in nitrocellulose), an even better blasting visited the university and introduced her to the
agent; and he profited from oil wells he owned in ideas of the ‘new’ algebra.
Russia. His inventions were wide-ranging, and cov- After the retirement of her father and Gordan
ered by 355 patents. His fortune was large and and the death of her mother in 1915, Hilbert
much of it was left to endow the Nobel Prizes. invited her to Göttingen. After 7 years she was
Element 102 is named nobelium after him. given the title of ‘unofficial associate professor’ and
Noddack, Ida (Eva), née Tacke (1896–1979) German later a small salary. She applied her knowledge of
inorganic chemist: co-discoverer of rhenium. invariants to problems Hilbert and Klein were con-
Ida Tacke was educated in Berlin and then sidering and was able to provide an elegant pure
worked in the Physico-Chemical Testing Laboratory mathematical formulation to aspects of Einstein’s
there with W Noddack (1893–1960), whom she mar- general theory of relativity. She taught at
ried. With O Berg they searched for the missing ele- Göttingen 1922–33, with visiting professorships at
ment 75, predicted by Moseley’s results. They Moscow (1928–9) and Frankfurt (1930). In April
found it in 1925 in traces in the mineral columbite 1933 she and other Jewish professors were dis-
and named it rhenium after the Rhine. They also missed. Through the efforts of Weyl she was offered
claimed to have found element 43, but were mis- a visiting professorship at Bryn Mawr College in the
taken in this claim. USA, and she worked at Bryn Mawr and at the
In 1934 Fermi had obtained unclear results by bom- Institute for Advanced Study, Princeton. In 1935
barding uranium with slow neutrons. Ida Noddack she had surgery for an ovarian cyst and died 4 days
suggested that nuclear fission had occurred, but later.
Fermi and others were unconvinced and her idea was Emmy Noether’s most important contributions
rather passed over. The same idea offered by Frisch to mathematics were in the area of abstract alge-
5 years later was speedily examined and accepted, bra. Weyl divided her career into three periods: rel-
and dramatic results soon followed. ative dependency 1908–19; investigations around
Noether, Emmy (Amalie) [noeter] (1882–1935) the theory of ideals 1920–6, when she was influ-
German mathematician of distinction. enced by the work of Dedekind and profoundly
The daughter of Max Noether, professor of mathe- changed the appearance of algebra; and non-com-
matics at Erlangen, Emmy Noether was a member mutative algebras 1927–35. Her work was original
of a talented family; her three brothers were scien- and creative, and inspired her successors in
tists and her mother a musician. She was allowed to abstract algebra to create a ‘Noether school’.
Norrish, Ronald G W (1897–1978) British physical
attend lectures in mathematics and foreign lan-
guages (she planned to become a teacher) as a non- chemist: a founder of modern photochemistry.
matriculated auditor at the University of Erlangen Born and educated in Cambridge, Norrish served
(1900–02). In 1903 she moved to Göttingen to spe- in the artillery in the First World War and became
cialize in mathematics, but almost immediately the a prisoner of war, taking up his science course in
University of Erlangen changed its policy and Cambridge in 1919. He spent his whole career
there. His best-known work was done from 1945
onwards, in collaboration with George Porter. The
latter had served as a naval radar officer in the
Second World War, and, initially guided by Norrish,
they devised methods for studying very fast photo-
chemical reactions. Their method (flash photolysis)
used a brief (microseconds) intense light flash, fol-
lowed by photography of the absorption spectrum
to record and identify the short-lived chemical
species produced by the light. (Later, Porter used
lasers to study processes lasting only 10–12 s.)
Norrish and Porter shared the Nobel Prize for chem-
istry in 1967 with Manfred Eigen (1927– ) who
had studied fast reactions in solution: Norrish’s
work was mainly on gas reactions.
Northrop, John Howard (1891–1987) US bio-
chemist: obtained a range of crystalline enzymes.
Educated at Columbia University, New York,
Northrop worked throughout his career at the
Rockefeller Institute in the same city, starting in
Emmy Noether
Northrop, John Howard

1916. In 1926 J B Sumner (1877–1955) had for the and also ribonuclease and deoxyribonuclease. They
first time crystallized an enzyme (a biochemical were found to be proteins (as, in fact, all enzymes
catalyst) and showed it to be a protein. (Remarkably, appear to be). This work changed both attitudes
he was a skilled bench chemist, despite losing his and techniques; enzymes were no longer regarded
left arm in a gun-shot accident in his teens.) However, as mysterious, and the availability of pure enzymes
the value of this work, on the enzyme urease, was was of great value in laboratory work. Later, in
insufficiently grasped by most researchers. Northrop 1938, Northrop isolated a bacterial virus and
saw its importance and used similar methods to showed this also to be a type of protein (a nucleo-
obtain pure crystalline samples of other enzymes; protein). He shared the 1946 Nobel Prize for chem-
he did this in the early 1930s. His pure enzymes istry with Sumner and Stanley, who had first
included the digestive enzymes trypsin and pepsin, crystallized a plant virus.

Occhialini, Guiseppe Paolo Stanislao [ohkah- there in 1900, passing her examinations in German
leenee] (1907– ) Italian physicist: discovered the with highest honours in zoology, geology and
pi-meson. palaeontology and with a thesis on recent and fossil
Occhialini graduated from the University of corals. She published on the microscopic skeletal
Florence and taught there until 1937. He belonged structure of recent Medreporarian corals in
to the school of physics around Fermi and, like Transactions of the Royal Society and on the Upper
others, he left Italy with the growth of fascism. Jurassic corals of the Stramberg fauna through the
After São Paulo, Brazil (1937–44), Bristol University Bavarian Royal Academy of Sciences.
(1944–7) and the University of Brussels (1948–50), She married Dr John Gordon, a physician in
Occhialini held professorships at Genoa and Milan Aberdeen, who sometimes accompanied his wife
(1952). on her excursions. She continued her researches
Working with Blackett, he obtained cloud-cham- in the Dolomites; her later work appeared in the
ber photographs that showed the positron for the Austrian Geological Survey. In 1932 she was awarded
first time (1933), thus confirming Dirac’s theory, the Lyell Medal of the Geological Society of London.
but they did not publish their results until after She was one of the first women to be appointed a
those by C D Anderson. In 1947 Occhialini and Justice of the Peace.
Ohm, Georg Simon (1789–1854) German physicist:
Powell discovered the pi-meson (or pion) by observ-
ing a cosmic ray particle of mass 300 times that of discovered relationship between current and volt-
an electron. age in a conductor.
Oersted, Hans Christian (1777–1851) [oersted] Ohm was educated at the University of Erlangen.
Danish physicist: discovered that an electric cur- He held rather minor academic posts in Cologne,
rent produces a magnetic field. Berlin and Nuremberg before being appointed pro-
Oersted studied physical science and pharmacy at fessor of physics at Munich in 1849.
the University of Copenhagen and, after a period of Ohm formulated the law for which he is now best
travel, journalism and public lecturing he was known early in his career, in 1827, but received
appointed professor of physics there in 1806, later little recognition for 20 years. Ohm’s Law states
becoming Director of the Polytechnic Institute in that the current flowing in a conductor is directly
Copenhagen. proportional to the potential difference across it,
Oersted is remembered for his discovery that an provided there is no change in the physical con-
electric current flowing through a wire induces a ditions (eg temperature) of the conductor; the
magnetic field around it, something that he felt on constant of proportionality is known as the con-
intuitive grounds ought to be true. In a famous exper- ductance of the conductor, the reciprocal of the
iment first performed in front of his students in 1820, resistance. Ohm came to this conclusion by an anal-
he placed a magnetic compass needle directly below ogy with Fourier’s work on heat flow along a metal
a wire; when the current was switched on the needle rod. He also discovered that the human ear is capa-
moved slightly. His discovery led to a surge of activity ble of breaking down complex musical sounds into
by other physicists interested in electricity and mag- their component frequencies, an important con-
netism. He also obtained the first accurate value for clusion but again one that was ignored at the time.
the compressibility of water, in 1822. The SI unit of electrical resistivity, the ohm (Ω), is
Ogilvie Gordon, Dame Maria Matilda, née named in his honour. It is defined as being the resis-
Ogilvie (1864–1939) British geologist: one of the tance of a conductor through which a current of
first professional women geologists. one ampere is flowing when the PD across it is one
volt, ie 1 Ω = 1 V A –1. (The unit of conductivity, the
Maria Ogilvie, the eldest daughter of the Rev
Alexander Ogilvie, a prominent educationalist, inverse of resistivity, was formerly known as the
attended the Ladies College, Edinburgh until she mho and now the siemens.)
Olah, George (Andrew) (1927– ) Hungarian–US
was 18. Her first interest was music and she became
a student at the Royal Academy of Music in London, organic chemist: expanded knowledge of carbo-
with success. She was then a student at University nium ions.
College, London, studying geology, botany and In reactions of hydrocarbons, it had been thought
zoology, and gained her BSc in 1890. She produced for some time that carbonium ions (‘carbocations’,
a thesis on the geology of the Wengen and St having a trivalent positively charged carbon-atom)
Cassian strata in southern Tyrol and for this, in may be involved as short-lived highly reactive inter-
1893, she obtained the London DSc, becoming the mediates.
first woman to do so. Olah, a graduate from Budapest, left Hungary in
From 1891–5 she studied at the University of 1956 after the Soviets crushed a popular movement
Munich and was the first woman to obtain a PhD to secure political freedom. While working in Canada
Oort, Jan Hendrik

for the Dow Chemical Co., he found that carbo- and fiction writer Edgar Allan Poe (1809–49) in a
nium ions could be made and preserved in ultra- lecture, and reprinted in his book Eurika in 1848.
Oldham, Richard Dixon (1858–1936) British seis-
strong acid solvents, such as ‘magic acid’ (a
solution of antimony pentafluoride SbF5 in fluor- mologist and geologist: first observed P and S waves
sulphonic acid HSO3F) and their spectra and reac- and discovered the Earth’s core.
tions studied. The new information on carbonium Oldham was educated at the Royal School of Mines,
ions is valuable in the petrochemical industry. in 1879 joining the Geological Survey of India (of
Olah won the Nobel Prize in 1994. which his father was director). Upon retirement in
Olbers, Heinrich (1758–1840) German astronomer: 1903 he became director of the Indian Museum in
discovered Pallas and Vesta, and presented the Calcutta. Following the violent Assam earthquake of
Olbers paradox. 1897, Oldham was able clearly to distinguish in the
Olbers, a physician and amateur astronomer, dis- seismograph record for the first time between the P
covered two asteroids, Pallas and Vesta, and redis- (primary, or compressional) and S (secondary, or
covered the asteroid Ceres (discovered by Piazzi, shear) waves (predicted theoretically by Poisson) and
but lost again). He suggested that the asteroids orig- the tertiary (surface) waves. In 1906 he discovered
inated in a small planet in the same orbit which that at points on the Earth’s surface opposite to the
had exploded. He also found five comets, one of epicentre of an earthquake the P waves arrive later
which is named after him, and devised an accurate than expected, when compared with their arrival
method of calculating their orbits. times at other places on the globe. He correctly rec-
He is now best known, however, for his phrasing ognized this as clear evidence for the existence of a
in 1823 of a deceptively simple, but important relatively dense Earth’s core, through which P waves
question: ‘why is the sky dark at night?’ This travel more slowly than in the mantle.
quandary, noticed by Kepler in 1610 and discussed In 1913 Gutenberg showed that the core is at
by Halley, became known as the Olbers paradox. least partly liquid; and in 1936 Inge Lehmann
He assumed that the stars are evenly distributed deduced that within it there is a solid inner core.
and infinite in number (as Newton proposed) and Earlier than this, Mohorovi˘i´ had shown that
presented the thought that, in whatever direction the Earth’s outer crust must be less dense than the
we look in the night sky, it would be expected that mantle, and had calculated the thickness of the
the line of sight will end on the surface of a star. In crust. All of these geophysical studies depended on
which case, he argued, the entire night sky ought to seismological results.
Oort, Jan Hendrik [oh(r)t] (1900–92) Dutch astrono-
have a brightness comparable to that of the Sun.
In modern cosmology the problem has been re- mer: detected the rotation of the Galaxy and pro-
examined and the present answer seems to be that posed theory for origin of comets.
the expansion of the universe has the effect that, at Oort worked mainly in Leiden, as director of the
a certain distance, objects are receding from Earth Observatory from 1945–70. In 1927 he proved, by
at the speed of light. This limits the seeable size of extensive observation of the proper motion of stars,
the universe, and within this limited radius there that our Galaxy is rotating, with the nearer stars to
are not sufficient stars in all directions to yield a the centre having higher angular velocities than
bright night sky. Alternatively, we can conclude more distant ones (recalling that the inner planets of
that the universe is of finite size and contains a the Solar System move more rapidly than the outer
finite number of stars. These answers to the para- ones). He established that the Sun is about 30 000
dox were probably first given by the American poet light years from the centre of the Galaxy and that it
completes an orbit in about 225 million years,
moving at 220 km s –1. The Galaxy has a mass about
1010 times that of the Sun. He was influential in the
discovery in 1951 of the 21 cm radio emission from
interstellar hydrogen, which has allowed the distrib-
ution of interstellar gas clouds to be mapped. This
technique has also revealed a large ‘hidden’ mass of
stars at the centre of the Galaxy. In 1956 Oort
observed that light from the Crab supernova rem-
nant was strongly polarized, implying that it was syn-
chrotron radiation produced by electrons moving at
relativistic velocities through a magnetic field.
In 1950 Oort suggested the existence of a sphere
of incipient cometary material surrounding the
Solar System, at a distance of about 50 000 AU and
with a total mass of perhaps 10–100 times that of
the Earth. He proposed that comets occasionally
detached themselves from this Oort cloud and
went into orbits about the Sun. Because the cloud is
spherical comets can approach the Sun at any
angle, and not just in the plane of the ecliptic.
Heinrich Olbers
Panel: Science and the Second World War

SCIENCE AND THE SECOND environmental problems; the work of RACHEL CARSON
WORLD WAR (1939 – 45) and others led to limitations in their use. During the
war a new class of poison gases was developed in
The Second World War initiated projects of great Germany and made on a large scale. These are the
importance both to the outcome of the war and to intensely toxic organophosphorus esters (‘nerve
improvement of everyday life afterwards. gases’) such as Sarin (the lethal dose for humans
Innovations directly attributable to the pressures of is below 1 mg). Although not used in the war
the war effort include radar, which was begun before (the reasons are unclear) related compounds have
1939 in England and Germany with the British team been much used since, as insecticides in agriculture.
led by WATSON-WATT; air and sea transport has bene- Turbojet aircraft engines were developed by
fited since and the microwave oven is a side product. WHITTLE in England and in Germany by P von Ohain
Radio astronomy was shaped by radar equipment (1911– ), and were first used in British military air-
and methods. Operations research (a mathematical craft in 1941. After the war, jet propulsion largely
modelling technique) grew out of the radar pro- replaced propellers in powering aircraft.
gramme and protection against submarine warfare. The Manhattan Project, which led to the atomic
Penicillin, the first antibiotic, discovered by A FLEMING bomb and nuclear power, was work of massive scale
in 1928, was developed for clinical use by 1944 by and significance. At the time, its financial cost and
FLOREY and CHAIN. Penicillin and related antibiotics the scientific and technical effort were vast, as were
have dominated the treatment of many infections the military, political, energy-generating and envi-
since. Computers were initially developed in the USA ronmental consequences. As those working on the
to calculate artillery trajectories, and in the UK by project foresaw, the world was grossly changed after
TURING and others for decrypting the German ‘Enig- a controlled fission reactor, and later weapons based
ma’ code messages. This decrypting programme on both fission (the A-bomb) and fusion (the H-
(‘Ultra’) was notably successful and, by diminishing bomb), became practical realities from 1945. If the
the effects of the Battle of the Atlantic and the (air) First World War was a chemist’s war, the Second was
Battle of Britain, was critical in deciding the outcome a physicist’s war.
of the entire war. Thereafter, computerized control Some novel schemes were only partial successes:
has proved central to calculation in business, and for the Allied invasion of France in 1944, PLUTO,
developments include home entertainment and the a fuel pipeline under the Channel, was partly
control of space flight. successful; the huge transportable harbours
The German V-2 missile (the first ballistic missile) (eg Mulberry) were valuable; the idea of a floating
was developed by VON BRAUN for warfare; he later airfield of ice (refrigerated and reinforced with
headed the NASA space probe programme in the wood pulp), code-named Habakkuk, proved a false
USA. Pesticides (notably DDT, due to P H MĂśLLER), trail.
curbed typhus during and after the war but their
later use to control agricultural insect pests caused IM

Oparin, Alexandr Ivanovich (1894–1980) Russian Oppenheimer, (Julius) Robert [openhiymer]
biochemist: pioneered chemical approach to the (1904–67) US theoretical physicist: contributed to
origin of life. quantum mechanics and the development of the
Although his training and his work was in plant atomic bomb.
physiology in Moscow, Oparin’s name is most Oppenheimer was born into a wealthy New York
familiar through his initiation from the 1920s of family and was educated at Harvard and Göttingen.
modern ideas on ‘the origin of life’, a phrase now In 1929 he took up posts at both the University of
much linked with him. He emphasized that early in California at Berkeley and California Institute of
the Earth’s history its atmosphere did not contain Technology, having studied under Rutherford,
oxygen (which was generated later, by plant photo- Heisenberg and Dirac whilst travelling in Europe.
synthesis); that simple organic substances could When the Manhattan Project (to develop an atomic
have been present in a ‘primeval soup’ before life bomb) was set up in 1942, Oppenheimer was asked
began; and that the first organisms were probably to become director of the Los Alamos laboratories
heterotrophic, ie used organic substances as food where much of the work was done. Having carried
and were not capable, as present-day autotrophs out this role with great skill, leading to the rapid
are, of feeding on simple inorganic substances. development of the bomb, he attempted to remain
Oparin believed that the key characteristics of life a Government adviser on nuclear weapons, but was
are its organization and integration, and that the forced to resign in 1953. He became director of the
processes which led to it should be susceptible to Institute for Advanced Study at Princeton in 1947
reasonable speculation and experiment; he did and remained there after his retirement in 1966.
much to make these attitudes respectable. Oppenheimer’s early success in research began in
Otto, Nikolaus August

1930 when he analysed Dirac’s relativistic quan- consulting entomologist to the Royal Agricultural
tum mechanics and theory of the electron (1928). Society and in 1898 was recommended for a newly
He showed that a positively charged anti-particle created lectureship in agricultural entomology at
with the same mass as the electron should exist, Edinburgh University, but women were not yet
and this positron was first seen by C D Anderson in acceptable. In 1900 Edinburgh University awarded
1932. During the 1930s Oppenheimer built up a for- her their first honorary LLD offered to a woman.
midable team of young theoretical physicists Eleanor Ormerod was a prime mover in making
around him, the first time that the subject had economic entomology an important specialty within
been studied intensely outside Europe. In 1939, biology and agricultural science.
Ostwald, Friedrich Wilhelm [ostvahlt] (1853–
working on stellar structure, he showed that any
massive star, when its thermonuclear energy is 1932) German physical chemist: pioneer of modern
exhausted, will collapse to form a black hole, which physical chemistry.
has mass but from which light cannot escape. Modern physical chemistry was largely created by
After 1942 as director of Los Alamos he concen- three men; van ’t Hoff, Arrhenius and Ostwald.
trated on gathering scientists and generating an His parents were German but they had settled in
atmosphere of urgency, skilfully handling the Latvia, then under Russian domination. He had a
interface between his military superior, General happy childhood, with some hobbies of a fairly
Groves, and the unorthodox research scientists chemical kind: painting (he ground his own
under him. colours), photography (he made his own wet plates)
Oppenheimer’s wife and brother were left-wing and firework-making. He had to repeat one school
sympathizers and possibly communists, and he ran year, and he had problems with the compulsory
into difficulties in 1943 when Groves demanded Russian language. He studied chemistry at Dorpat
the name of a communist agent who had (now Tartu) University, did well and became pro-
approached Oppenheimer; after much delay he fessor at the Riga Polytechnic in 1881. His fame
finally gave it. The first atomic test explosion took spread, and in 1887 he was called to Leipzig
place in July 1945, and two atomic bombs ended the University, where he remained. His work in physi-
war with Japan a month later. cal chemistry was wide-ranging; he studied the
After the war Oppenheimer initially continued his rates of hydrolysis of salts and esters, the conduc-
important role in atomic energy, but he opposed the tivity of solutions, viscosities, the ionization of
development of the hydrogen (fusion) bomb. In 1953 water and catalysis; he was awarded the Nobel
his political background and his support for the Prize in 1909. He took up new ideas in physical
Super Program (the hydrogen bomb project) were chemistry with enthusiasm, did much to unify and
questioned, and President Eisenhower removed his expand the subject, and saw the study of the ener-
security clearance, ending his Government service. getics of chemical reaction as central to the subject.
However, the Fermi Award was conferred on him by For a long time Ostwald believed that atoms were
President Johnson in 1963, implying that doubts only a convenient hypothesis and had no real exis-
about his integrity had been resolved. tence; but in the 20th-c direct evidence for them
Ormerod, Eleanor (Anne) (1828–1901) British had arrived and by 1908 he was a late convert to
economic entomologist. ‘atomism’.
Otto, Nikolaus August (1832–91) German engi-
Eleanor Ormerod was born at Sedbury Park, her
father’s large estate in Gloucestershire, which pro- neer: effectively devised the four-stroke internal
vided the insects that prompted her interest in combustion engine.
entomology and in the infestation of crops. Apart
from an elementary education from her mother, a
botanical artist, she was self-taught. One brother
became an anatomist and surgeon and from him
she gained experience of using a microscope. She
became an expert on insect infestations.
She got in touch with the Royal Horticultural
Society in 1868 and offered to compile a collection
of insects injurious or helpful to farmers. The
resulting collection was awarded the Flora Medal
in 1870. She corresponded with entomologists
throughout the world and published on insect
pests and their control, often subsidizing and dis-
tributing the pamphlets free. In 1881 she published
her Manual of Injurious Insects, with Methods of
Prevention and Remedy, and in 1898 the Handbook of
Insects Injurious to Orchard and Bush Fruits, with Means
of Prevention and Remedy. Between 1877 and 1900 she
undertook an Annual Report on economic ento-
mology and during the 1880s she became a suc-
cessful public lecturer. From 1882–92 she was N A Otto
Panel: The history of the heat engine

THE HISTORY OF cylinder. It was then held by a catch while the steam
THE HEAT ENGINE cooled and condensed, with a consequent reduction
in its pressure. When the catch was released, atmos-
An engine is a mechanical contrivance by means of pheric pressure acting on the top of the piston forced
which some form of energy is converted to useful it back to the bottom of the cylinder. Although
work. The first mechanical utilization of an energy Papin’s arrangement had limited application, it was
source to do work dates back to the 1st-c BC, when a significant step towards the goal of obtaining a
simple water wheels were used to lift water from practical steam engine.
rivers and to mill grain. Although it might be consid- In 1698 Thomas Savery (c.1650–1715), an English
ered that these were examples of simple hydraulic engineer, patented a steam pump which could be
‘engines’, it is generally accepted that the term used to pump water out of mines. His machine was a
engine is associated with a much later period of tech- simple arrangement with no piston and requiring the
nological development; that of the Industrial hand operation of valves. It used steam above atmos-
Revolution. Engines are normally associated with the pheric pressure. Since it did not have automatic
conversion of fossil fuels (thermal energy sources) safety valves, and as reliable boilers had not been
into useful work, and so we may fully refer to them as perfected, the Savery pump proved to be dangerous
heat engines. and it was eventually abandoned. About the same
The most significant heat-engine development period Thomas Newcomen (1663–1729) was also
was that of the steam engine. The use of steam to engaged in the design of a steam-operated pumping
produce a mechanical effect has its origin in the engine. Newcomen’s design was different from
1st-c AD, when the mathematician and inventor HERO Savery’s, but as the latter’s patent was very general
of Alexandria described a steam-operated ‘wheel’ and protected the rights for the raising of water ‘by
which utilized the thrust effect of escaping steam the impellent force of fire’, it was necessary for
jets. This device was really only a toy, and no attempt Newcomen to liaise with Savery in 1705 to come to
was made to find a use for it. Hero demonstrated some arrangement regarding the manufacture of his
other interesting arrangements and, although none engine. In 1712 the first practical Newcomen steam
of them led to the development of a practical heat engine was constructed. It was an atmospheric
engine, he did go some way to demonstrate that engine and was thus dependent for its operation on
when a fluid such as water or air is heated, it is obtaining a pressure within the cylinder below that of
possible to use it to bring about some form of atmospheric pressure; this was achieved by injecting
mechanical effect. cold water into steam in the cylinder. This engine
In 1661, GUERICKE, in Magdeburg, invented a proved to be a significant breakthrough in atmos-
device consisting of a close-fitting piston within a pheric engine development, and Newcomen-type
pipe with a closed end. Using a vacuum pump (which engines were manufactured and sold in numbers for
he had also developed), he created a partial vacuum mine pumping.
inside the pipe, the pressure there falling below that While preparing a model of a Newcomen engine
of the atmosphere. Atmospheric pressure acting on for Glasgow University in the winter of 1763–64,
the other side of the piston then forced it into the WATT, a Scottish instrument-maker, realized that a
pipe. The piston was connected by a system of ropes considerable amount of heat was wasted by succes-
and pulleys to a weight which was then raised. This sively heating the cylinder to produce steam and sub-
was the forerunner of the various heat engines which sequently cooling it to condense the steam. He
were generally categorized as atmospheric engines, proposed a major improvement to Newcomen’s
since they all made use of the fact that atmospheric design, by the use of a cooling chamber (a condenser)
pressure, in conjunction with a partial vacuum separate from the steam cylinder. His design also
created within a piston–cylinder arrangement, could incorporated an air pump which, by sucking air out of
do useful work. the condenser, created a partial vacuum which
It was the Frenchman Denis Papin (1647– assisted condensation of the steam. This allowed a
1712) who first had the idea of constructing an large increase in the overall efficiency of the engine.
atmospheric engine which made use of the evapora- Watt obtained a patent for his engine in 1769. In
tion and condensation properties of water. In 1689 order to exploit his invention commercially, he joined
he demonstrated what was in effect an embryo forces with the leading Birmingham manufacturer,
steam engine. It consisted of a vertical hollow cylin- Matthew Boulton (1728–1809). This was a very sig-
der with a base, above which was a piston. A small nificant industrial partnership, and the widespread
amount of water within the piston-cylinder arrange- use of Watt’s engine began in 1776–77. Watt’s
ment was heated; steam was generated and it was engine was much lower in coal consumption than
allowed to expand, thereby pushing the piston up the Newcomen’s, which was an attractive selling point.

Panel: The history of the heated engine

In 1782, Watt patented a double-acting engine in engines, owing to their stringent manufacturing
which steam was used alternately below and above requirements, are confined to special applications,
the piston to produce a power stroke in both direc- such as submarines and spacecraft.)
tions, thereby making it more suitable for the In 1824 CARNOT published his work which, in dis-
eventual use of a rotative motion, required to cussing steam engine efficiency, created the new
operate factory machinery. Both the Newcomen and science of thermodynamics. The next 30 years saw
Watt engines transmitted work through massive several designs and patents for gas engines, but most
beams. of them were never constructed; those that were had
Further developments in steam engine design did limited success. The first internal combustion engine
not take place until the early 1800s, when steam able to operate reliably was built by the Belgian-born
above atmospheric pressure was investigated. The inventor Jean Joseph Lenoir (1822–1900). In 1860,
Cornish engineer Richard Trevithick (1771–1833) he patented a well-thought-out design for a gas
realized that the need to create a vacuum within the engine. The fuel was lighting gas (derived from coal)
cylinder, requiring a cumbersome and heavy con- mixed with air. This engine was a two-stroke, double-
denser, could be replaced by making use of high- acting design, with the fuel-air mixture fed into the
pressure steam. This was a departure from the cylinder alternately at either end of the piston. The
atmospheric type of engine. He perfected the first Lenoir engine was slow-running (200 rpm), and the
high-pressure steam engine in about 1803. In the gas-air mixture was not compressed before ignition.
same year he also built the first steam locomotive at It lacked power, and it had a very high fuel consump-
the Coalbrookdale ironworks, thereby giving a tion. Despite this, it sold in reasonable numbers, and
further boost to the Industrial Revolution. From the so became the first internal combustion engine to
1830s steam locomotives dominated rail transport compete with the long-established dominance of
for over a century. steam. In 1862, the French engineer Alphonse Beau
In parallel with the early development of the de Rochas (1815–93) described the much more effi-
steam engine, several inventors pursued the idea of cient four-stroke cycle. However, his proposed engine
an engine in which the combustion of a fuel would was never constructed, and he allowed his patent to
take place within a piston-cylinder arrangement. In lapse. It was the German engineer OTTO who con-
1673 the Dutch scientist HUYGENS demonstrated a structed the first four-stroke internal combustion
piston engine to the French Académie des Sciences. It engine in 1876. This design was a significant one
was an atmospheric-type engine which made use of a from the viewpoint of the development of the motor
small quantity of explosive. It worked by displacing car. These early internal combustion engines all oper-
cold air from the cylinder by means of the hot gases ated on gas. The use of liquid fuels was not intro-
from the explosion. When the hot gases remaining in duced until near the end of the 19th-c. In 1883, the
the cylinder cooled and contracted, the cylinder gas German engineers Gottlieb Daimler (1834–1900) and
pressure was lower than the atmospheric pressure Wilhelm Maybach (1846–1929) designed an engine
outside the arrangement and, like other atmospheric- that could operate on petrol. It ran faster than Otto’s
type engines, movement of the piston was effected. engine and was capable of obtaining more power for
This invention was unfortunately thwarted by the a given weight of engine. In 1889 the engine was
inability to find a suitable fuel. It was much later that installed in a car designed by Maybach, which is con-
it was found that when coal is heated in a closed sidered to be the first modern motor car. The heavy-
vessel a combustible gas (coal gas) is given off, which oil engine was pioneered in Britain in 1890 by Herbert
forms a suitable fuel. Akroyd-Stuart and improved by the German engineer
In 1816, Robert Stirling (1790–1878), a Scottish DIESEL. In 1893, Diesel patented a prototype four-
clergyman, developed another concept; that of an stroke engine. This engine differed from the petrol
engine with air as the operating medium. His engine engine in that ignition of the fuel occurred sponta-
consisted of two cylinders. In one of them air was neously without a spark. The high compression
heated (by an external source) and cooled alter- attained within the cylinder resulted in sufficiently
nately. When the air expanded, it effected a power, high temperatures to bring about ignition of the fuel
or working, stroke in the other cylinder. This engine and effect a pressure stroke. The Diesel engine has of
was a closed-circuit, hot-air type, and its operating course found wide use for both marine and land
principle was later seen to be based on excellent ther- transport.
modynamic considerations. Stirling obtained a patent Another, more recent development in internal
for his design in 1827. Some engines were manufac- combustion engine design was the rotary engine,
tured industrially in 1844, but they never attained invented in 1956 by the German engineer WANKEL.
mass production. Later, Stirling engines used helium In this engine the conventional reciprocating action
and hydrogen. (Even up to the present time, these of pistons in cylinders is replaced by the rotary

Otto, Nikolaus August

Four-stroke engine cycle. (1) Fuel and air drawn into cylinder. (2) Fuel/air mixture compressed and ignited by spark.
(3) Power stroke. (4) Exhaust gases expelled.

fuel valve spark plug exhaust valve





(1) (2) (3) (4)

motion of an ingeniously designed rotor within a and Diesel engines seem destined to continue their
specially shaped chamber. This design has not found dominance.
widespread application within the automobile
Dr W K Kennedy, Open University
industry, in which conventional petrol engines

Although he lacked conventional engineering stroke (see diagram above). The new engine was
experience, Otto became fascinated by the gas quiet and fairly efficient and sold well. However, in
engine devised by J Lenoir (1822–1900); this was a 1886 his competitors showed that A B de Rochas
double-acting low-compression engine and the first (1815–93) had suggested the principle in an obscure
internal combustion engine to be made on any scale. pamphlet, although he had not developed the idea,
Otto and two friends began to make similar engines; and this invalidated Otto’s patent. Soon Otto’s gas
and then in 1876 he described the system usually engine, mainly used in small factories, was devel-
called the Otto cycle, in which an explodable mix- oped for use with gasoline (petrol) vapour and air,
ture of air and gas is drawn into the cylinder by the using a carburettor to control the mixture and
piston (the induction stroke), compressed on a improved ignition systems; the resulting engine was
second (compression) stroke, ignited near the top well suited for the motor car. In these developments
dead centre piston position (the combustion stroke, K Benz (1844–1929), G Daimler (1834–1900), W
in which the hot expanding gases provide the power Maybach (1846–1929) and F W Lanchester (1868–
to drive the piston) and the burned gases are then 1946) all played important parts, and the result is
driven out of the cylinder on a fourth (exhaust) still dominant for this purpose. (See panel.)

Palade, George Emil (1912– ) Romanian–US cell tinism are related; and he used morphine, sulphur
biologist: discoverer of ribosomes. and lead in medicine, and mercury, with which he
Palade qualified in medicine at Bucharest and treated the then new disease syphilis. He gave good
became professor of anatomy there. When Soviet descriptions of several types of mental disease,
forces entered Romania in 1945 he moved to the which he saw as an illness and not as due simply to
USA, working first at the Rockefeller Institute and demons. However, he firmly claimed that it is pos-
from 1972 at Yale. His work was particularly on the sible to create human life in the laboratory and
fine structure of cells as revealed by electron gave full experimental detail on how to achieve
microscopy. He showed beyond doubt that one type this, starting with the fermentation of a sample of
of organelle, the mitochondrion (typically 1000 of semen.
Parsons, Sir Charles Algernon (1854–1931) British
these small sausage-shaped structures are present
in each animal cell) form the sites where energy (in engineer and inventor: designed the first effective
the form of adenosine triphosphate, ATP) is gener- steam turbine.
ated by enzymic oxidation, to meet the energy Some of Parsons’s talents can be seen in his parents;
needs of the cell. In 1956 he discovered smaller his mother was a talented modeller and photo-
organelles (now called ribosomes) found to be rich grapher and his father (the Earl of Rosse) was an
in ribonucleic acid (RNA) and showed that they are astronomer who made and used some outstanding
the sites of protein synthesis. Subsequently he telescopes (his 65 in (1.65 m) reflector at Parsonstown
worked out in detail the pathway followed by secre- in Ireland was without rival, and he used it to dis-
tory proteins in glandular cells. He shared a Nobel cover much about nebulae) and was president of
Prize in 1974. the Royal Society.
Pappus (of Alexandria) (lived c.300) Greek mathe- Charles studied in Dublin and Cambridge, did
matician: made major contributions to geometry. well and then became an engineering apprentice.
The name of a son is the only detail known of His firm had interests in electric lighting and he
Pappus’s personal life; but his account is the main saw the need for a high-speed engine to drive
source of knowledge of parts of Greek mathematics dynamos. For this he devised the multistage steam
before his time, and his own contributions to geom- turbine, which he patented in 1884; it used high
etry are substantial. Theorems named after him pressure steam and ran at up to 20 000 rpm.
deal with the volume and surface generated by a Parsons set up his own company to make turbo-gen-
plane figure rotating about an axis in its own plane. erators, and from the early 1890s developed his tur-
His work was the high point in the field of Greek bines also for marine use. For this he devised
geometry. reduction gearing, and he also studied the cavita-
Paracelsus (Lat), Theophrastus Bombastus von tion due to propeller blades and improved their
Hohenheim (Ger) (1493–1541) Swiss alchemist and design. At the 1897 Naval Review on the Solent to
physician: pioneer of medical chemistry. celebrate the Queen’s Jubilee, his 48 m Turbinia,
Paracelsus’s father was a physician working near with Parsons at the wheel, created a sensation; its
ZĂĽrich, who gave his son his early medical training. 2000 hp moved it at an unheard-of 34 knots. By
The young man travelled widely before settling in 1906 his turbines were fitted in the warship HMS
Strasbourg. There he achieved cures for some influ- Dreadnought, and soon the great Cunarders followed
ential people and as a result was appointed City suit; some of his turbines generated 70 000 hp.
Physician in Basle. In lectures and books he pressed He went on to design searchlights for naval use,
the view that alchemy should be directed not only and large telescopes. The company of Grubb
to transmuting base metal into gold, but princi- Parsons have retained their special position in this
pally to preparing effective medicines. His ideas field. Parsons used his scientific and mathematical
found support, but he used such offensive language skill to stride ahead of existing engineering prac-
in abusing opponents that, following a legal case tice and to become a leading engineer of his time,
which he lost, he had to leave Basle, and he died in the first to join the Order of Merit and the most
Salzburg. He was certainly a loud-mouthed and original British engineer since Watt. Power gener-
often drunk and boastful mystic; but he probably ation and marine propulsion were never to be the
did much to deflect alchemy towards improving same after his work.
Pascal, Blaise [paskahl] (1623–62) French math-
medical chemistry.
His theoretical ideas were too clouded in mysti- ematician, physicist and philosopher: pioneer of
cism to be useful, but in practical medicine he was theory of probability.
more effective. He was one of the first to study occu- Educated by his father, Pascal showed early intel-
pational diseases and he recognized silicosis as a lectual ability, proving one of the most important
hazard for miners. He realized that goitre and cre- theorems of projective geometry by the age of 16.
Pasteur, Louis

the pascal (Pa), defined as a force of one newton per
square metre, commemorates his work on hydro-
statics, and the modern programming language
Pascal marks his contribution to computing.
Pasteur, Louis [paster] (1822–95) French chemist
and microbiologist: founder of stereochemistry
and developer of microbiology and immunology;
exponent of germ theory of disease.
Pasteur is one of the greatest figures in science,
who made major changes in all the fields in which
he worked. He was enormously talented, with great
powers of scientific intuition; he was also ambi-
tious, arrogant, combative and nationalistic.
His father served in the Peninsular War and then
returned to the family tanning business in DĂ´le,
near the Swiss border. Louis was the only son; there
were three daughters. His school record was only
moderate, but just good enough for him to go to
Paris and to hope for entry at the teacher training
college, the École Normale. In preparing for this for
a second time (the first time his physics was classed
as ‘passable’ and chemistry ‘mediocre’), he went to
lectures on chemistry by Dumas, along with 700
other students. The subject captured him, he
became a ‘late developer’, and all his future work
showed a chemical approach even to biological
Blaise Pascal and his calculator of 1642 His first major research, done at the École
Normale, concerned tartaric acid (a by-product in
He was fervently religious, belonging to the rigor- wine making). Biot had shown that one form of the
ous Jansenist sect of the Roman Catholic church. He acid is optically active (ie it rotates polarized light
was also neurotic, dyspeptic and humourless. when in solution). Pasteur examined a salt of the
Much of Pascal’s early work was on projective optically inactive form of tartaric acid and showed
geometry, developed from his paper on conic sec- that the crystals were of two kinds, which were
tions of 1640 from which he deduced 400 proposi- non-superposable mirror-images of each other (ie
tions, deriving most of those put forward by were dissymmetric). He separated these and
Apollonius. The most notable was Pascal’s theo- showed they were both active, with equal and oppo-
rem (for any hexagon inscribed in a conic, the inter- site rotation. He deduced, correctly, that the mole-
sections of opposite pairs of sides are collinear), cules themselves must therefore be dissymmetric,
also known as the problem of Pappus, which had a fundamental idea and one that was more fully
been used by Descartes as a test case for the power explored by van ’t Hoff. It was the beginning of
of his own analytical geometry. At the age of 19 stereochemistry.
Pascal invented a calculating machine that could
add and subtract, in order to help his father with
his business; he built and sold about 50 and several
survive. Later, his interest moved towards physics,
demonstrating with the help of his brother-in-law
that air pressure decreased with altitude as Torri-
celli had predicted, by taking a mercury barometer
to the summit of Puy de DĂ´me (a height of 1200 m,
near Clermont Ferrand) in 1648. His interest in
hydrostatics also led him to demonstrate that pres-
sure exerted on a confined fluid is constant in all
directions (Pascal’s Law). Together with Fermat, he
also developed the mathematics of probability and
combinatorial analysis, using the familiar Pascal
triangle to obtain the coefficients of the successive
integral powers of the binomial (p + q)n. In 1655,
after a profound religious experience, Pascal entered
the Jansenist retreat at Port Royal, where his sister
was already a nun, and he did little further mathe-
matical work. His philosophical work Pensées was
published in 1670. The SI unit of pressure (or stress), Louis Pasteur, aged 18
Paul, Wolfgang

This work had interested Pasteur in fermen- two equal groups, and one group of 25 was inocu-
tation, and when he became professor of chemistry lated with ‘attenuated’ vaccine. After 2 weeks all 50
at Lille in 1854 he found this useful, because alco- were given an injection of a strong anthrax culture.
hol-making was Lille’s main industry. Back at the Two days later, a crowd formed to see the dramatic
École Normale from 1857 he continued this inter- result: the protected 25 were all healthy; of the
est, which was to carry him from chemistry to biol- others, 22 were dead, two dying, one sickening.
ogy and from there to medicine. In becoming a In 1880 he began to study rabies. The work was
microbiologist and improving wine- and beer- dangerous, and difficult because the first step he
making technology in his early middle-age, Pasteur wished to take – isolation of the pathogen – was not
became convinced that spontaneous generation then possible; it is now known to be a virus.
did not occur. Work by Spallanzani and by However, he could inject dogs, guinea pigs and rab-
Schwann should have established the view bits with rabid saliva and thereby infect them; and
expressed by Virchow: ‘all cells come from cells’. he found that spinal cord from a rabid rabbit, if
But the experimentation is not easy and the debate kept in dry air for a few days, formed an attenuated
continued. However, Pasteur’s now-classic studies vaccine which could be used to protect and to treat
showed in the early 1860s that putrefaction of other animals. However, he was understandably
broth and fermentation of sugar did not occur fearful of human trials. Then in 1885 he was
spontaneously in sterile conditions, but could be brought 9-year-old Joseph Meister, who had been
readily initiated by airborne microorganisms. He bitten 14 times by a rabid dog. The child was treated
put his view with typical force, and it has been gen- with the vaccine, survived and later became a care-
erally accepted since. He introduced pasteurization taker at Pasteur’s institute. In 1886 2671 patients
(brief, moderate, heating) to kill pathogens in wine, were treated, and only 25 died. This success made
milk and other foods. Since fermentation, putre- Pasteur world-famous, and an Institute was built
faction and suppuration of wounds were fairly for his research, by public subscription; it was
widely regarded as kindred processes, it was rea- opened in 1888. But by then he was old and ill, and
sonable for Lister to use Pasteur’s principles to rev- rabies was his last success. Pasteur’s notebooks
olutionize surgery, but Pasteur himself was not were not opened to the public until 1971. It then
involved in this. However, in 1860 he said he emerged that some of his trials were very inade-
planned to work in medicine, and he eventually quate and some claims improved on the record; for
achieved his own revolution there. example, the vaccine used on Meister appears to
His first experience with animal diseases was have been tested on only a few dogs and not on 50
with silkworms, then a major French industry but as Pasteur later claimed.
much threatened by infections. Pasteur, helped by Medicine was never the same after his work;
a microscope and his fermentation experience and infectious disease could now be combated by estab-
with wife, daughter and several assistants acting lished techniques and research guided by a general
with him as novice silk-growers, fairly soon estab- theory. Vaccines were sought against most major
lished procedures to deal with the two infections diseases, but only in some cases could a vaccine be
then rife. Then, in 1868 when he was 46, he had a made. Pasteur had all the marks of genius, includ-
stroke; he was fully paralysed for 2 months and ing an intuition on when to continue with a study
partly paralysed thereafter. His work habits were of details until success followed and when to leave
unchanged, but his irritability increased. Most a field for other workers to explore. He had a
experiments now had to be performed under his number of distinguished co-workers; the best was
direction but not with his own hands. In one way his wife. He was buried in the chapel of the Pasteur
this suited him; he disliked vivisection, but saw it Institute in Paris. In 1940 the invading Nazis
as essential for some of his research, and preferred ordered Meister to open the ornate crypt for inspec-
others to perform the work. tion, but the gatekeeper chose to kill himself rather
Only in the late 1870s did Pasteur achieve success than do so.
Paul, Wolfgang (1913–93) German physicist.
against a disease in a larger animal. In 1879 by a for-
tunate chance he noted that if a chicken-cholera Paul studied at Munich and Berlin before moving
bacillus culture was ‘aged’ or ‘attenuated’ by stor- to Göttingen and Bonn. Paul with Hans Dehmelt
age, it failed to produce the disease in chickens on (1922– ) introduced and developed the ion trap
injection; but the injected chickens (after an inter- technique which has allowed single electrons and
val) were resistant even to infection by a fresh cul- ions to be studied with amazing precision. Paul
ture. He deduced that the change in virulence of began such experiments in the 1950s by focusing
the culture on attenuation, so that it protected but atoms in a beam using a six-pole magnetic field. He
did not infect, could be compared with the use of showed that ions of different masses could be sepa-
the mild cowpox vaccine against the virulent small- rated using a four-pole electrical field with a radio-
pox, studied by Jenner before 1800. Pasteur used frequency field added, and this is now a standard
the idea to make a vaccine against anthrax (a major method called the Paul trap. The Penning trap can
disease of cattle, and sometimes found in man). The also be used, and was developed simultaneously by
scheme worked well, and Pasteur staged a demon- Paul and by Dehmelt in Seattle, WA. Dehmelt went
stration for agriculturists in May 1881 on a farm. A on to observe a single electron in a trap, and was
herd of 50 sheep, cows and goats was divided into able to cool it. This allowed the g-factor of the elec-
Pauli, Wolfgang

tron (ie, its magnetic moment) to be accurately observed more directly by F Reines (1918–98) in
measured, a key test proving the validity of quan- 1956.
tum electrodynamics (‘QED’). The subject of single Pauli had a caustic wit; he was not a good lecturer
ion spectroscopy quickly grew thereafter. Dehmelt and he was notoriously bad as an experimentalist;
served in the German army and was taken prisoner but he is one of the giants of 20th-c theoretical
by the US Army in 1945 before studying at physics.
Pauling, Linus (Carl) [pawling] (1901–94) US
Göttingen and joining the University of Washington
(Seattle) ten years later. chemist: the outstanding chemist of the 20th-c.
Pauli, Wolfgang [powlee] (1900–58) Austrian– Pauling’s chemical beginnings were very ordi-
Swiss–US physicist: discovered the Pauli exclusion nary. He grew up in a country area in Oregon, and
principle in quantum mechanics. his father (a pharmacist) died when he was 9; the
The son of a professor of physical chemistry at the boy began experimenting with chemicals when he
University of Vienna, Pauli obtained his PhD at was 11 and continued at school. By 15 he had
Munich in 1921. Encouraged by Sommerfeld, Pauli decided to become a chemical engineer. He attended
had written (when he was only 19) an article, sub- the small Oregon Agricultural College and did well
sequently published as a small book, on relativity enough (especially in chemical analysis) to be paid
that was admired by Einstein for its ‘deep physical to teach first-year students. He went on to the
insight’. Pauli studied further with Bohr in California Institute of Technology, working for his
Copenhagen and Born in Göttingen. He then PhD on X-ray studies of inorganic crystals. He read
taught at Hamburg and gained a professorship in intensively and his memory was remarkable. He
1928 at the Federal Institute of Technology, ZĂĽrich, began to develop a scheme to assign sizes to atoms
remaining there until his death, except for 5 war in crystals, and used these dimensions to work out
years spent at Princeton (when he became a US the structures of a wide range of minerals, includ-
citizen). ing eventually the silicates and some other major
Working on quantum mechanics, he contributed groups which had previously been seen as a struc-
the Pauli exclusion principle (1924), which tural mystery. After his PhD in 1925, he spent 2
explained much about atomic structure. The prin- years studying in Europe, mainly in Germany with
ciple requires that no two electrons in an atom can Sommerfeld. This led him to an extensive study of
be in the same quantum state. The original Bohr– the use of quantum theory in understanding chem-
Sommerfeld model of the atom (1915) specified for ical bonds. By the early 1930s he had largely devel-
each electron in an atom three quantum numbers oped the valence-bond (VB) approach to bonds,
(n,l,m) and Pauli additionally required the electron using concepts such as ‘hybridization’ of bonds and
to have another, called the spin quantum number s ‘resonance’ for calculating bond energies, lengths
= ± . Pauli’s principle that no more than one elec-
tron is able to occupy a state described by n, l, m
and s then gave the correct formation of electronic
shells in atoms, gave a theoretical basis for the peri-
odic classification, and explained the Zeeman
effect of atomic spectra. This concept of spin, able
to have one of two values, was verified experimen-
tally by Goudsmit and Uhlenbeck in 1926. For his
idea of the exclusion principle Pauli was awarded
the Nobel Prize for physics in 1945. It was much
Pauli also studied the relation between the spin
of a particle and the statistics of energy level occu-
pancy (quantum statistics); the paramagnetic prop-
erties of gases and metals (including electrons in
metals); the extension of quantum mechanics from
one to a large number of particles; the explanation
of the meson and the nuclear binding force.
Furthermore, Pauli solved a major problem con-
cerning beta decay, in which atomic nuclei eject
electrons and apparently contravened the conser-
vation of energy principle. The energies of emitted
electrons cover a continuous range up to a maxi-
mum value, and it was unclear what happened to
the ‘missing’ energy if an electron had less than the
maximum. Pauli realized that this energy could be
carried off by an undetected, very light neutral par-
ticle (named the neutrino, Italian for ‘little neutral
one’, by Fermi) emitted at the same time as the elec-
tron. This was correct and the neutrino was first Linus Pauling
Payne-Gaposchkin, Cecilia

and shapes and magnetic properties. He also devised a dog’s mouth causes gastric juice to flow; this is an
an electronegativity scale, valuable in predicting example of an unconditioned reflex. If a bell is
bond strength. From his return to Caltech in 1927 always rung before food appears, the dog will soon
he held a position there for 35 years, together with salivate when the bell is rung even without the
others in California. food.
In the 1930s he began to work on biochemical Such conditioned or trained reflexes are easily
problems, beginning with X-ray studies on the pre- induced in dogs, but can be established in other
cise shape of amino acids and peptides. From this animals; they can be linked with stimuli other than
he went on to deduce two model structures for pro- sound and depend on a response in the cerebral
teins: these are the ‘pleated sheet’ and ‘α-helix’ cortex. Pavlov did extensive and ingenious work on
types, both found in important biological struc- such reflexes, and since then others have studied
tures. Other ventures in biochemistry included the- conditioning both in the laboratory and in the
ories of the chemical basis of anaesthesia and of wild, and in vertebrates and invertebrates. Pavlov
memory; and with DelbrĂĽck he studied the struc- was a critic of Soviet communism and tried to move
ture and action of antibodies. Here he used the new abroad in 1922 but failed. Despite this his work was
idea of ‘complementary structures in juxtaposi- well funded, and it remains more highly regarded
tion’. This last idea, together with his ideas on helical in Russia than outside it, where it has certainly
structures in biomolecules and on hydrogen-bond- given a psychological dimension to physiology but
ing as an important determiner of their shape, even more has contributed to behaviourist
form the key aspects of Crick and Watson’s model approaches to psychology.
Payne-Gaposchkin, Cecilia (Helena), née Payne
of DNA as a self-replicating double helix. Also in the
1940s he proposed that sickle-cell disease (a genetic (1900–79) British–US astronomer: the most emi-
anaemia) resulted from a change in the normal nent woman astronomer and a founder of modern
amino acid content of haemoglobin; proof of this astrophysics.
gave the earliest example of a disease being traced As a very English middle-class child, Cecilia Payne
to its precise origin at the molecular level. was sent to a church primary school. Precocious as a
Pauling’s work has generated some controversy: pupil in mathematics, languages and music, she also
his views on the value of a high vitamin C level in tested the efficacy of prayer by dividing her exams
the diet in combating a range of ills from the into two groups, and prayed for success in one group
common cold to old age are not universally only; she got better marks in the group without
accepted and his political views in pursuit of world divine help, and was agnostic thereafter. She went
peace led to problems (his passport was withheld on to St Paul’s Girls School, Hammersmith, and to
for a time). He won two Nobel Prizes; for chemistry Newnham College Cambridge in 1919. In that year,
in 1954, and for peace in 1962. His elementary texts Eddington lectured on the ‘eclipse expedition’ he
remain among the best available. had led whose results had verified Einstein’s predic-
His work in science is exceptional in its range, tions on the deflection of stellar images close to the
covering inorganic and organic chemistry, theoret- Sun, and thereby provided experimental support for
ical chemistry and practical devices, work on min- relativity theory. Cecilia Payne by chance attended
erals and in biology. His work in chemistry is the lecture; the experience changed her life and cre-
without peer in the 20th-c in its vitality, vision and ated the devotion to physics and astronomy which
significance. His contributions to novel chemical dominated it thereafter.
theory continued in his 80s. After Cambridge she took a fellowship to the
Pavlov, Ivan Petrovich (1849–1936) Russian physi- Harvard College Observatory at Cambridge MA and
ologist: discoverer of the conditioned reflex. spent her career there. The vast collection of stellar
When Pavlov graduated in medicine at St Peters- spectra gathered and classified by Williamina
burg in 1875 he had already done useful research in Fleming (1857–1911), Antonia Maury and Annie
physiology, and his interest was mainly in this field Jump Cannon was available to her and provided
rather than in practical medicine. In the 1880s he rich material for her PhD thesis (the first in astron-
studied in Germany and from 1890 he held omy approved by Harvard) which was published in
research posts in St Petersburg, finally building up 1925 as Stellar Atmospheres. In it she used their data
a very large research centre. to deduce temperature, pressure and composition
In the 1890s Pavlov studied digestion, using great for a variety of stars, concluding that their compo-
surgical skill to modify dogs so that, for example, sition was surprisingly constant, with helium and
part of the stomach (a ‘Pavlov pouch’) could be sep- hydrogen as dominant constituents (although she
arated from the rest and its gastric juice collected. hardly believed this herself for a time). Her work
He discovered the secretory nerves to the pancreas, gave a new basis for astrophysics, although it was
and he studied the nerves and action of the salivary written too early for nuclear reactions to have a
glands. During this work he noted the way in which place in her thinking. Before she was 30 she had
dogs salivate when stimulated by the routine of written another major book, on The Stars of High
feeding, even before the arrival of food; this led him Luminosity (1930), the stars much used to find stellar
to the study of reflexes which became his life-long distances. She never lost her passion for stellar
and best-known work, although his Nobel Prize of spectra, but by 1942 she turned to the study of
1904 was for his work on digestion. He knew food in variable stars.
Peano, Giuseppe

no more creative mathematics, working on a gen-
eral European language (Interlingua) and on the
history of mathematics.
Pearson, Karl (1857–1936) British statistician: pio-
neer of statistics applied to biology.
Pearson’s father was a barrister and Karl also
qualified in law but never practised; but he did well
in Cambridge in mathematics and afterwards stud-
ied physics and biology in Germany. At his
Cambridge college he successfully rebelled against
compulsory chapel attendance and then infuriated
the authorities by occasional appearances there. In
1884 he became a professor of mathematics at
University College, London and was soon influ-
enced by two colleagues there, Galton and W
Weldon (1860–1906) – both enthusiasts for the
application of arithmetic to the study of evolution
and heredity. In the 1890s Pearson developed sta-
tistical methods for a range of biological problems,
largely published in a journal he did much to
found, Biometrika. His forceful and effective work
led him to define standard deviation (an idea
already well established) and to break new ground
Williamina Flemming on graphical methods, probability theory, theories
of correlation and the theory of random walk. In
Valued by her peers but always underpaid, she 1900 he devised the chi-square test, a measure of
became the first woman professor at Harvard only how well a theoretical probability distribution fits
in 1956. By then she had married (a fellow astro- a set of data, that is valuable in showing, for exam-
physicist, Sergei Gaposchkin, in 1934), had a ple, whether two hereditary features (eg height and
family, travelled widely and been widely honoured. eye colour) are inherited independently; or
She was an active researcher until shortly before whether one drug is more effective than another.
her death. His productivity was enormous, right up to his
Peano, Giuseppe [payahnoh] (1858–1932) Italian death, and his work largely founded 20th-c statis-
mathematician: introduced the Peano axioms into tics.
Peierls, Sir Rudolf Ernest [payerlz] (1907–95)
mathematical logic.
Peano grew up on a farm and from the age of 12 German–British theoretical physicist: contributed
was taught privately in Turin. On winning a schol- to solid-state physics, quantum mechanics and
arship to Turin University his talent was fully nuclear physics.
revealed, and by 32 he held a professorship there. Peierls was educated at Berlin, and then studied
The lack of rigour in mathematics provoked him under Sommerfeld in Munich, Heisenberg in
(like Dedekind) to try to unravel the areas where Leipzig and as Pauli’s assistant in Zürich. Research
intuition had concealed the logic of analysis. in Rome, Cambridge and Manchester followed and
During the 1880s he looked at the integrability of in 1937 he was appointed professor at Birmingham.
functions; he proved that first order differential In 1963 he moved to Oxford and from 1974–77 to
equations y’ = f(x,y) are always solvable if the func- the University of Washington, Seattle.
tion f is continuous. In 1890 this was generalized to Peierls began research in physics during the
the first statement of the axiom of choice. In the dawn of quantum mechanics in 1928; the basic
same year he demonstrated a curve that is continu- theory was complete but its applications to almost
ous but filled space, indicating that graphical every physical system hardly begun. Peierls studied
methods are limited in the analysis of continuous the theory of solids and analysed how electrons
functions. move in them, concentrating on the effect of mag-
Peano worked on the application of logic to math- netic fields (notably the Hall effect). In 1929 he
ematics from 1888, producing a new notation. He explained heat conduction in non-metals, predict-
also wrote down a set of axioms that covered the ing an exponential growth of their thermal con-
logical concept of natural numbers (Peano axioms), ductivity at low temperatures, as was verified in
later acknowledging that Dedekind had antici- 1951. He also developed the theory of diamagnet-
pated him in this. Peano’s work in this area was ism in metals.
probably more important than that of the other Turning in 1933 to nuclear physics, he began to
great figures – Boole, F L G Frege (1848–1925) and B work out how protons and neutrons interact, and
Russell (1872–1970). in 1938 showed how resonances (or dramatic
Peano also initiated geometrical calculus by increases in interaction) occur at particular beam
applying the axiomatic method to geometry. energies in nuclear collisions. After the Second
However after 1900 his interests shifted and he did World War had begun, Peierls and Frisch studied
Perey, Marguerite

uranium fission and the neutron emission that into one mass that falls inside the hole and the
accompanies it with a release of energy. In an influ- remainder, which is ejected. Curiously, the ejected
ential report (1940) they showed that a chain reac- mass-energy must exceed that of the original
tion could be generated in quite a small mass of matter, so that the Kerr black hole has lost mass-
enriched uranium, giving an atomic bomb of extra- energy on accreting matter. Overall, Penrose’s
ordinary ferocity. The British Government took this research adds much to our knowledge of gravita-
up, and Peierls led a theoretical group developing tion, and he added to the efforts to formulate a sat-
ways of separating uranium isotopes and also cal- isfactory quantum theory of gravity, which are as
culating the efficiency of the chain reaction. The yet unsuccessful.
Penzias, Arno Allan (1933– ) US astrophysicist:
work was moved to the USA as part of the combined
Manhattan Project (1943), and by 1945 yielded the discovered the 3 K microwave background radiation.
first atomic weapons and quickly brought the war A refugee from Nazi Germany, Penzias was edu-
with Japan to an end. cated in New York and joined Bell Telephones in
Pelletier, Pierre-Joseph [peltyay] (1788–1842) 1961.
French chemist: founder of alkaloid chemistry. In 1948 Gamow, Alpher and R Herman (1914–97)
Pelletier followed the family profession of phar- hypothesized that the radiation released during
macy and studied at the École de Pharmacie in the ‘Big Bang’ at the creation of the universe ought
Paris, and afterwards taught there. From about to have permeated the universe and progressively
1809 he began to examine natural products, using cooled, to a present-day temperature of about 5 K.
mild methods of separation (mainly solvent extrac- In 1964 Dicke and P J Peebles (1935– ) at Princeton
tion) rather than the older methods such as repeated and extended this theoretical work. At the
destructive distillation. An early success was his iso- same time, but unknown to them, Penzias and his
lation of chlorophyll from green leaves; and in 1817 colleague R W Wilson were exploring the Milky
with Magendie he isolated the emetic substance Way with a radio telescope having a 6 m horn
from ipecacuanha root and named it emetine. In reflector at the Bell Telephone Laboratories in New
the next few years he isolated a series of ‘vegetable Jersey, a mile or two away. Working at a wavelength
bases’ from plants; they are the cyclic nitrogenous of 7 cm they found more radio noise than they had
bases now known as alkaloids, which often show expected, or could account for from any known ter-
potent physiological properties. With his friend J restrial source (they even excluded the effect of
Caventou (1795–1877) he isolated strychnine, pigeon droppings on the radio telescope’s surface).
brucine, colchicine, veratrine and cinchonine, and The signal was equally strong from all directions
(later) piperine and caffeine. Their most valuable (including apparently empty sky), and corre-
discovery was quinine from cinchona bark (1820), sponded to that emitted by a black body at about
which for a century was the only effective treat- 3.5 K. Their discovery provided some of the
ment for malaria and was almost the earliest strongest evidence for the ‘Big Bang’ theory for the
chemotherapeutic agent in the modern sense. origin of the universe, and is arguably the most
Penrose, Sir Roger (1931– ) British theoretical important discovery, bearing on cosmology, made
physicist: major contributor to theories on black in the 20th-c. Penzias and Wilson were awarded the
holes. Nobel Prize for physics in 1978.
Perey, Marguerite [pairay] (1909–75) French
Son of a distinguished geneticist and expert on
mental defects, Penrose studied at University nuclear chemist: discoverer of actinium K (fran-
College, London, and Cambridge. After posts in cium); the first woman to be elected to the
London, Cambridge and the USA he became profes- Académie des Sciences.
sor of applied mathematics at Birkbeck College, Marguerite Perey’s first wish was to study medicine,
London (1966), and Rouse Ball Professor of but the death of her father made that impossible. She
Mathematics in Oxford (1973). joined Marie Curie’s staff as a junior laboratory assis-
Penrose revealed many of the properties of black tant in 1929, and almost left when she found the con-
holes by his research. Black holes occur when large ditions of work so austere, but she remained at the
stars collapse and reach a density such that even Institute for 20 years. In 1939 she discovered a new
light (photons) cannot escape from the intense chemical element, which she named francium (Fr)
gravitational attraction. The ‘event horizon’ marks after her country. It had been intensively looked for by
the region within which light cannot escape. many experienced researchers, and was found by the
Hawking and Penrose proved that a space-time sin- modest 29-year-old technician. She found this by a
gularity (a point, having mass but no dimensions) careful study of the radioactive disintegration of the
arises at the centre of a black hole, and Penrose rare natural radioelement actinium, showing that, by
established that event horizons always prevent us a series of changes, this is converted into francium.
from observing these singularities from the out- The element is one of the isotopes with atomic
side. They also argued, in 1970, that the universe number 87, and is the heaviest of the alkali metal
must have begun as a singularity, from which the group and the most electropositive element known. It
‘Big Bang’ developed. is exceptionally rare in nature, is itself radioactive and
However, if a black hole is rotating but un- is now made artificially by atomic bombardment. It
charged, (a Kerr black hole) it possesses a region has been estimated that the entire Earth’s crust (to a
around it in which matter will always be broken depth of 1 km) contains only 15 g of francium, and its
Perkin, Sir William Henry

rarity and intense radioactivity both point to the ele- Synthesis of quinine was not achieved until 1944,
gant work and skill of its discoverer. Encouraged to by Woodward and W von E Doering (1917– ).
Perl, Martin Lewis (1927– ) US physicist.
take a degree course during the Second World War,
she obtained her degree in 1946. Perl grew up in Brooklyn, New York, the son of
Perey became head of research and, subse- Jewish immigrants from Poland, and qualified as
quently, administrator and director of the nuclear a chemical engineer at Brooklyn Polytechnic
research centre at Strasbourg, and held a chair there Institute. He worked for GEC on production prob-
from 1949. She received the Légion d’honneur, lems, and left to take a doctoral programme in
Grand Prix Scientifique de la Ville de Paris (1960), physics at Columbia in 1950, working on atomic
Lauréate de l’Académie des Sciences (1950 and beam resonance to study atomic nuclei under Rabi.
1960) and the Silver Medal of the Chemistry Society Between 1974 and 1977 Perl and colleagues at the
of France (1964). She was elected to the Institut de Stanford Linear Accelerator Center demonstrated
France as the first woman member of the Académie experimentally the existence of the tau lepton,
des Sciences in 1962. some 3500 times heavier than an electron. This dis-
Perkin, Sir William Henry (1838–1907) British covery unveiled the third lepton family of funda-
chemist: made first synthetic dye and founded mental particles, a vital piece of supporting
organic chemical industry. evidence for the theory now known as the Standard
Young Perkin’s interest in chemistry began in a Model within particle physics. Before the third
familiar way. He records that when he was about family (consisting of the tau particle and its neu-
trino, νr) was discovered, theories could not allow
12, ‘a young friend showed me some chemical
experiments and the wonderful power of sub- charge and parity (CP) violation, which had (most
stances to crystallize in definite forms especially surprisingly) been observed. This asymmetry in our
struck me… and the possibility also of making new world regulates particle decay and is a very impor-
discoveries impressed me very much…. I immedi- tant subtlety in the structure of the universe.
ately commenced to accumulate bottles of chemi- Previously only the first family (the electron and
cals and make experiments.’ Despite his father’s electron neutrino) and second family (mu particle
opposition Perkin entered the Royal College of and mu neutrino) were known. Corresponding to
Science to study chemistry at 15. At 17 he was assist- these six leptons there are six quarks (up and down,
ing Hofmann there, and also doing some research charm and strange, and top and bottom for the first
at home. Hofmann had mentioned the desirability to third families respectively). One of the funda-
of synthesizing quinine. Perkin, at home for Easter mental questions in physics is whether only three
in 1856, tried to make quinine by oxidizing aniline. families of leptons exist; or will the standard model
The idea was quite unsound, but Perkin noticed require revision? Perl received the 1995 Nobel Prize
that the dark product contained a purple sub- for his discovery, shared with Frederick Reines
stance, later named mauve, that dyed silk. At age (1918–98) who had first observed the electron neu-
18, helped by his father, he set up a small factory to trino. He and Clyde Cowan had proposed a reactor
make his ‘mauve’ and, later, other synthetic dyes experiment to capture neutrinos, as reactors
based on coal tar products. Remarkably, they dealt should produce quite intense flows of such parti-
successfully with the novel problems of chemical cles. Despite the neutrino’s properties making it
manufacture and marketing, although little com- very difficult to observe, their experiment conclu-
mercial equipment or material was available (they sively demonstrated its presence. This confirmed
even had to make nitric acid, and re-purify coal tar the vital hypothesis put forward by Pauli in 1930,
benzene) and their skills were those of the 18-year- required to explain beta decay (emission of an elec-
old boy and his retired builder father. Young Perkin tron) whilst ensuring conservation of energy.
even maintained his academic research, solving by Pauli’s fear had been that his suggested particle
1860 some important problems on organic acids might always remain unobservable and place
and synthesizing the amino acid glycine. Mauve physics in a realm of ongoing speculation.
Perrin, Jean Baptiste [per˜ (1870–1942) French
manufacture went on for 10 years; it was used for ı]
textiles and the Victorian 1d lilac postage stamp. physical chemist: gave first definitive demonstra-
Later Perkin manufactured magenta and alizarin tion of the existence of atoms.
dyes. By age 36, he was able to retire as a dyemaker Perrin studied in Lyon and Paris, and in 1910
and pursue his research exclusively. He developed a became professor of physical chemistry at the
general synthesis of aromatic acids (the Perkin Sorbonne, but fled to America in 1941.
reaction) and studied magnetic rotatory power. While studying for his doctorate, Perrin investi-
Chemical interests seem to run in the family; a gated cathode rays, showing them to be negatively
grandfather had a laboratory in his Yorkshire farm- charged and obtaining a rough value of their
house and Perkin’s three sons were all distin- charge/mass ratio by measuring the negative
guished organic chemists. His own venture began charge required to stop them illuminating a fluo-
the synthetic organic chemical industry, in which rescent screen. His work showed that the rays are
leadership soon passed to Germany. Academic particles and not waves, and J J Thomson was soon
organic chemistry was maintained in Britain espe- to improve upon his results and show them to be
cially by his son Professor W H Perkin Jr (1860–1929) electrons. Perrin is better known, however, for his
and his pupils at Edinburgh, Manchester and Oxford. classic studies of Brownian motion in 1908, in
Phillips, Peregrine

which he measured the distribution of particles of tied in with his passion for skiing and moun-
gamboge (a yellow gum resin from a Cambodian taineering). He joined the Order of Merit in 1988 (a
tree) suspended in water. His results confirmed a UK decoration for those providing valued service to
mathematical analysis of the problem by Einstein, the country, restricted to 24 members).
Peters, Sir Rudolf Albert (1889–1982) British bio-
and enabled Perrin to give accurate values for
Avogadro’s number and for the size of the water chemist: wide-ranging discoverer of metabolic
molecule. His work was widely accepted as final paths in cellular metabolism.
proof of the existence of atoms, and he was Peters studied science in Cambridge and medi-
awarded the Nobel Prize for physics in 1926. He cre- cine in London, qualifying in 1915, and serving
ated several prestigious scientific institutions in with distinction in France in the First World War
France, including the CNRS (Centre National de la before his recall to the UK in 1917 to join the chem-
Recherche Scientifique). ical warfare defence laboratory at Porton Down.
Perutz, Max (Ferdinand) (1914–2002) Austrian– After the war he began his studies on the vitamin B
British molecular biologist: showed structure of complex in Oxford, and was the first to isolate thi-
haemoglobin. amine (vitamin B1), and he began to elucidate its
Both sides of Perutz’s family were textile manu- function as a precursor of a metabolic enzyme (co-
facturers. After studying chemistry in Vienna he carboxylase). He held the Oxford professorship of
came to Cambridge in 1936 to work for a PhD in biochemistry from 1923–54.
crystallography with J D Bernal (1901–71). The In the Second World War he again worked on
latter had shown in 1934, with Dorothy Crowfoot chemical warfare defence. Having noted that
(Hodgkin), that a wet crystal of a protein (pepsin) arsenical poisons inhibit enzymes, he led the work
would give an X-ray diffraction pattern, thereby which showed that 2,3-dimercaptopropanol con-
implying that it might be possible to use the X-ray denses with the arsenical poison gas Lewisite to
method that the Braggs had used for inorganic form a relatively harmless product. As a result of
compounds to deduce the structure of proteins. this, 2,3-dimercaptopropanol (‘British anti-Lewisite’,
However, Bernal gave Perutz some dull work on BAL) became available for use both in war and
minerals and it was 1937 before Perutz secured peace for the treatment of poisoning by arsenic and
some crystals of haemoglobin and found them to some other metals. As the value of BAL depends on
give excellent X-ray patterns. Haemoglobin is the the presence of mercapto (-SH) groups in BAL and
protein of red blood cells, which carries oxygen to in enzymes, this stimulated valuable world-wide
the tissues and CO2 to the lungs. studies on the importance of -SH groups in bio-
The invasion of Austria in 1938, and the Second chemistry generally.
World War (during which he was interned as an During the Second World War some compounds
alien for a time), diverted Perutz from protein work of fluorine were a major potential chemical war-
for a time; but from 1947 he directed a Medical fare threat, and then and afterwards Peters showed
Research Council Unit in Cambridge, consisting at how these compounds act, by inhibiting an essen-
first only of himself and his assistant J C Kendrew tial part of the Krebs metabolic cycle. Again, the
(1917–97) who had spent the war in radar, and oper- work had valuable spin-off results in pure bio-
ational research, with the RAF. In 1953 Perutz chemistry. He was also able to show in 1969 how
showed that the haemoglobin structure could be fluorine is incorporated, in organic form, as an
solved by comparison of two or more X-ray diffrac- important component of bone.
tion patterns, one from the pure protein and the Retiring from Oxford in 1954, he had two further
others from the same protein with heavy atoms careers, firstly with the Agricultural Research
such as mercury attached to it at specific positions. Council’s Animal Physiology Unit and then from
This method led to the solution of the first two pro- 1959 in Cambridge, where he was an active
tein structures; Perutz and his colleagues solved researcher until 1981. Uniquely, and through the
haemoglobin (relative molecular mass 64 500) and accidents of war, he had used chemical warfare
Kendrew and his colleagues solved the related (but problems as a source for unwarlike and valuable
simpler) myoglobin from sperm whale muscle. contributions to biochemistry.
Phillips, Peregrine (c.1800– ?) British vinegar
Their methods have been adopted and extended to
several hundred other proteins, including enzymes, manufacturer: devised contact process for sulphuric
antibodies and viruses. acid.
The Unit became the Medical Research Council Phillips’s position in science is curious; almost
Laboratory of Molecular Biology, chaired for many nothing is known about him, and the process he
years by Perutz and a focus of world talent in its patented in 1831 was not used by him on any scale.
field, attracting Brenner, Crick, H E Huxley, The old method of making sulphuric acid was by
Milstein and Sanger among others. Perutz and burning sulphur in a lead chamber, and then oxi-
Kendrew shared a Nobel Prize in 1962. Perutz went dizing the resulting SO2 with nitrogen oxides and
on to study the structural changes in haemoglobin absorbing the resulting SO3 in water. The Phillips
that occur when it takes up oxygen, and its mutant patent proposed to pass SO2 and oxygen over a plat-
forms, characteristic of some inherited diseases. inum catalyst to make SO3 and offered great advan-
Before 1950 Perutz also did research on the crystal- tages, but initial difficulties delayed its use until
lography and mechanism of flow of glaciers (which 1876 when R Messel (1847–1920) used it. Now, the
Phillips, William Daniel

process makes over 90% of the world’s sulphuric taught at the Sorbonne and at the École Normale
acid. Supérieure.
Phillips, William Daniel (1948– ) US physicist: Picard proved two theorems (known as his ‘little
developed methods of cooling to ultra-low temper- theorem’ and ‘big theorem’) which show that an
atures by use of laser light. integral function of a complex variable takes every
As a 12-year-old boy, Phillips spent his leisure in finite value, except for possibly one exception.
sports activities or experimenting with chemicals Picard also developed a theory of linear differential
and electricity, and survived the unheeded hazards equations which paralleled Galois’s theory of alge-
of asbestos, ultraviolet light, home explosives and a braic equations using group theory. By studying
carbon arc. His interest in science persisted and he integrals associated with algebraic surfaces he cre-
focused on physics in his degree course at the small ated areas of algebraic geometry with applications
Juniata College at Huntingdon, PA, and later at in topology and function theory.
Pincus, Gregory Goodwin (1903–67) US biologist:
The isolation and study of individual atoms has introduced the oral contraceptive pill.
long had a profound attraction – to see and analyse Pincus followed in his father’s footsteps by grad-
matter directly. Phillips, Steven Chu (1948– ) and uating in agriculture at Cornell; his father was a
Claude Nessim Cohen-Tannoudji (1933– ) inde- lecturer in the subject. Then he studied genetics
pendently contributed methods of using low tem- and physiology at Cambridge, Berlin and Harvard,
peratures and laser light to do this. Chu was and later founded his own consultancy in experi-
working at Bell Laboratories in 1985 when he devel- mental biology. In 1951 he was influenced by the
oped a means of cooling atoms in gases using laser birth control campaigner Margaret Sanger (1883–
radiation, to within 240 microK above absolute 1966) to concentrate on reproductive physiology.
zero without the gas freezing. The atoms within a With M C Chang (1908–91) he studied the anti-
pea-sized cloud were slowed from 4000 km h–1 to 30 fertility effect of steroid hormones (notably proges-
cm s–1 when they could then be held in traps using terone) in mammals, which act by inhibiting
magnetic coils. Phillips working at the National ovulation. In this way, refertilization is prevented
Bureau of Standards carried this further and by during pregnancy. Synthetic hormones similar in
1988 could achieve just 40 microK. By 1995 Cohen- their effects to progesterone became available in
Tannoudji at the Collège de France had reduced the 1950s, and Pincus saw that they could be used
this to 1 microK, corresponding to just 2 cm s–1. The to control fertility. He organized field trials of suit-
significance so far is in allowing much more accu- able compounds in Haiti and Puerto Rico in 1954
rate atomic clocks, improving their accuracy by a which were very successful, and oral contraceptives
factor of over 100, improving position measure- (‘the Pill’) have been widely used ever since. His suc-
ment, the measurement of gravitation and for cess is a pharmaceutical rarity – a synthetic chemi-
manipulating smaller electronic circuits. Chu, cal agent that is nearly 100% effective, and one that
Cohen-Tannoudji and Phillips shared the Nobel has had remarkable social results.
Planck, Max (Karl Ernst Ludwig) (1858–1947)
Prize for physics in 1997.
Piazzi, Guiseppe [pyatsee] (1746–1826) Italian German physicist: originated quantum theory,
astronomer: discovered the first asteroid, Ceres. making 1900 the transition between classical and
Piazzi, a monk of the Theatine Order who taught modern physics.
mathematics, became first director of the Palermo
Observatory in 1890. In 1814 he published a cata-
logue of 7646 stars visible from Sicily and estab-
lished that proper motion was a common property
of stars, and not only of a few nearby ones. He dis-
covered the first asteroid, Ceres, in 1801, but after
only three fixes of its position lost it, being tem-
porarily prevented from observing due to illness.
However it was soon recovered (by Olbers), follow-
ing a remarkable calculation of its orbit by Gauss,
based on the three observations. The 1000th aster-
oid was named Piazzia in his honour.
The asteroids have planetary orbits between Mars
and Jupiter, in the region assigned for a planet by
Bode’s mysterious ‘law’, although it was not found
through this by Piazzi, but by chance.
Picard, Charles Emile [peekah(r)] (1856–1941) French
mathematician: advanced analysis and analytical
Soon after entering the École Normale Supéri-
eure in 1874 Picard made some useful discoveries
in algebra and earned his doctorate. At 23 he
became a professor at Toulouse, and from 25 Max Planck in 1895
Poincaré, Jules Henri

The son of a professor of civil law, Planck coated with lead sulphate. Then a current (eg from
attended university at Berlin and Munich, finish- a dynamo) passed through the cell in the reverse
ing his doctorate in 1880. He then went to Kiel, direction recharges the cell, and brings the plates
becoming a professor there in 1885. A move to back to the original state. Their main use is in
Berlin in 1888 followed. In 1930 he became presi- motor cars, and their main defect is their weight.
Pliny (the Elder), in full Gaius Plinius Secundus
dent of the Kaiser Wilhelm Institute; he resigned in
1937 in protest at the behaviour of the Nazis (c.23–79) Roman writer on natural history: the first
towards Jewish scientists. At the end of the Second encyclopedist.
World War the Institute was moved to Göttingen Pliny was a child of a wealthy Roman family and
and renamed the Max Planck Institute and Planck so was well educated; at 23 he began an official
was reappointed president. career as a member of the second great Roman
In 1900 Planck published a paper which, together order, the equestrian order. His early duties, as was
with Einstein’s paper of 1905, initiated quantum usual, were in the army: he served in the cavalry on
theory. Kirchhoff, Stefan, Wien and Rayleigh had the Rhine frontier and his first writing was on the
studied the distribution of radiation emitted by a use of javelins by cavalry.
black body as a function of frequency and tempera- In about ad 57 he left the army and wrote on
ture. Wien found a formula that would agree with grammar and on Roman history, and travelled in
experiments at high frequencies, while Rayleigh the Roman empire as a financial controller. He
and Jeans found one for low frequencies. Planck must then have begun his most famous work, the
discovered one that worked at all frequencies ν, but 37 books of his Natural History. His last post was as
this needed the assumption that radiation is emit- commander of the fleet at Misenum near Naples.
ted or received in energy packets (called quanta); He probably never married, but adopted a nephew
these have an energy E = hv where h is the Planck (Pliny the Younger) as his heir. His energy as a
constant (6.626 × 10 –34 J Hz –1). This assumption is writer was remarkable: he needed little sleep, and
counter to classical physics and its adoption began his motto was ‘to live is to be awake’. He saw the
the modern age of using quantum theory in eruption of Vesuvius in ad 79, and was killed near
physics. The conservative Planck reluctantly recog- Pompeii by its fumes.
nized how revolutionary the result was, and on a He was a passionate gatherer of the scientific and
New Year’s Day walk in 1900 with his small son told technical knowledge of his time, ever-anxious to
him how the age of classical physics had just passed record the facts for posterity. He wrote that ‘it is
away. Rapid acceptance of the idea came with its god-like for man to help man’; and his curiosity was
use in Einstein’s prediction of the photoelectric boundless. His Natural History covers astronomy,
effect (1905) and in Bohr’s successful theory of the geology, geography, zoology, botany, agriculture
electronic structure of atoms (1913). A full quan- and pharmacology, and the extraction of metals
tum theory arrived in the 1920s, when Planck and and stone and their uses, especially in art. His
others had shown how to express all the new con- emphasis was on facts, and his theorizing spas-
cepts consistently. Planck was awarded the Nobel modic. His fact-gathering was uncritical and myth
Prize in 1919 for his discovery of the energy quanta. and legend are mingled with observation. Pliny has
Planck bore the tragedies of his second son dying a unique place as a source of information on the
in the First World War, his twin daughters both science and technology of his time.
Pogson, Norman (Robert) (1829–91) British
dying in childbirth and finally his first son Erwin
being executed for his part in the plot against astronomer.
Hitler of July 1944. He was always anti-Nazi, but the A keen youthful astronomer, Pogson by age 18
other founder of 20th-c physics, his friend Einstein, had calculated orbits for two comets. In 1851 he
never forgave Planck for not showing firmer oppo- became assistant at the Radcliffe Observatory,
sition; it is not clear that he could have achieved Oxford and by 1860 was government astronomer at
more. Planck is one of the very few scientists to be Madras, where he stayed. Although he discovered
immortalized on a coin (the German DM 2 piece of nine asteroids and 21 new variable stars and pre-
1958). pared a massive star catalogue, his best-known
Planté, (Raimond Louis) Gaston (1834–89) French achievement was devising (in 1854) Pogson’s ratio
physicist: inventor of the lead-acid storage battery. to define stellar magnitudes. It was known that
Planté was laboratory assistant to Becquerel and first magnitude stars are about 100 times brighter
later worked for a Paris electroplating firm, study- that sixth magnitude stars, so Pogson proposed
ing polarization in primary cells. This led him that each magnitude interval should correspond to
in 1859 to the invention of the lead-acid storage a brightness ratio of exactly 100 , ie 2.512. The
battery (‘accumulator’): originally this consisted system was used by E C Pickering (1846–1919) and
merely of lead plates immersed in dilute sulphuric his ‘Harvard ladies’ in their work on stellar pho-
acid. In its developed form, as improved by Planté tometry, a massive project which during 25 years
and by C A Faure (1840–1909) and J W Swan recorded over 1.5 million photometric readings.
(1828–1914) the negative electrode is a plate of The magnitude scale is still used.
PoincarĂ©, Jules Henri [pw˜
spongy lead, and the positive plate is coated with ıkaray] (1854–1912) French
lead dioxide. It gives 2V per cell, and when dis- mathematician: discovered automorphic functions
charged by providing current, both plates become and contributed independently to relativity theory.
Poisson, Siméon-Denis

Poincaré was the son of a physician and was edu- given number of events if its probability is low, and
cated at the École Polytechnique and École des it has wide applicability. The Poisson distribution,
Mines. After teaching at the University of Caen he which is related to this, was later shown to be a
spent his life from 1881 as a professor at the special case of the general binomial distribution.
University of Paris. He became a member of the Poisson also wrote an important memoir in 1833


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