ńňđ. 12
(âńĺăî 21)



In 1741 he was appointed professor of medicine 540 million years ago. From the common ancestor
and botany at Uppsala and was able to extend his three lines of descent began the tree whose
teaching, and his collection and investigation of branches now include nearly all existing animal
plants. Linnaeus’s passion for classification led him species.
Liouville, Joseph

Liouville, Joseph [lyooveel] (1809–82) French math-
ematician: developed the theory of linear differen-
tial equations.
Liouville held a professorship at the École
Polytechnique for many years (1838–51), then
moved to the Collège de France (1851–79). He was
briefly elected to the constituent assembly in 1848,
but his political career only lasted a year.
He is famous for developing Sturm–Liouville
theory, which is part of the theory of linear differ-
ential equations and important in physics; he
worked also on boundary-value problems. He made
further contributions in differential geometry,
conformal transformation theory and complex
analysis, influencing developments in measure
theory and statistical mechanics. He was the first to
prove the existence of transcendental numbers
(and an infinite number of them) and he suggested
that e is transcendental (1844); this was proved by Joseph Lister
Hermite. Liouville was also editor of the influential
Journal de mathématiques pures et appliquées from could be avoided by cleaning the hands of surgical
1836–74. operators, had been ignored.
Lipscomb, William Nunn (1919– ) US inorganic In 1865 Lister read Pasteur’s work on fermenta-
chemist: developed low temperature X-ray tion. Lister concluded that sepsis was akin to fer-
crystallography and devised structures for boron mentation and was initiated by infectious agents,
hydrides. some air-borne. By 1867 he had shown that antisep-
Educated at Kentucky and California, Lipscomb tic procedures are very successful; his methods
became a professor at Harvard in 1959. The boron were quickly adopted in Germany (eg in the Franco-
hydrides had first been made by Stock, but their Prussian War of 1870) and more slowly in Britain.
structures had proved mysterious; in terms of Lister used crude phenol solution as his preferred
established theory they appeared to be electron- antiseptic for dressings and instruments, and as a
deficient. Lipscomb deduced their structures in the spray in the air of the operating theatre. Later (from
1950s by X-ray diffraction analysis of their crystals 1887) he gave up the spray and increasingly used
at low temperatures, a technique which he and aseptic methods, with steam as a sterilizing agent.
others were to use later on a variety of chemical His work enormously reduced the incidence of
problems. He went on to theorize on the bonding in fatal post-surgical infection and encouraged sur-
the boron hydrides, to extend his ideas to the geons to develop abdominal and bone surgery.
related carboranes and to use nuclear magnetic res- Lister’s scientific work was largely related to his
onance methods to examine molecules. His ‘antiseptic system’; he published on inflammation,
approaches to these problems have proved highly bacteriology (he was probably the first to grow a
fruitful in chemistry; he was awarded a Nobel Prize microorganism in pure culture) and on surgical lig-
in 1976. atures and their sterilization (his preference was
Lister, Joseph, Baron Lister (1827–1912) British catgut). He revolutionized general surgery by
surgeon: introduced antiseptic surgery. making it safer and was widely honoured for his
Lister was the son of a Quaker wine merchant work.
Lobachevski, Nikolai Ivanovich [lobachefskee]
who was also a skilful microscopist; his achromatic
microscope design (1830) marks the beginning of (1793–1856) Russian mathematician: discovered
modern microscopy. As an Arts student in London, one of the first non-Euclidean geometries.
young Lister attended as a spectator the first surgi- Lobachevski’s father died when he was about 6,
cal operation under a general anaesthetic, in 1846. and after his mother had moved the family to
He then turned to medicine, qualified as a surgeon Kazan he attended the new university there in
in 1852 and worked in Edinburgh, Glasgow and 1807. He joined its staff in 1814 and in 1827 became
later in London. His main work on antisepsis was its rector. He was honoured by his government, but
done in Glasgow. At that time, surgery was usually in 1846 fell into disfavour for reasons which are
followed by inflammation and ‘putrefaction’; of unclear; he had done much for his university and
limb amputations about half were fatal from this his country.
sepsis, and abdominal surgery was largely avoided From 1827 onwards Lobachevski developed the
because of it. It was widely (but erroneously) first non-Euclidean geometry to be published,
thought that sepsis was due to air reaching moist although J Bolyai (1802–60) was doing similar work
tissues, and awkward but ineffectual attempts had at the same time and Gauss had done so decades
been made to exclude air from surgical sites. The before, but without publication. Euclid’s fifth pos-
work of Semmelweis in Vienna, in which he showed tulate (‘axiom XI’) could not be proved. The fifth
in 1846 that sepsis after childbirth in hospital postulate is that, given a straight line and a point,
Lodge, Sir Oliver

Early use of Lister's antiseptic surgical technique: a technician applies a spray of phenol solution to the surgical field in
1883. The surgeon is Sir Alex Ogstone.

just one straight line can be drawn in their plane unfamiliar solar spectral lines were caused by the
passing through the point and never meeting the dissociation of atoms into simpler substances with
other line. Euclidean geometry was widely thought their own spectra (the electron was not to be dis-
adequate to describe the world and the universe. covered until 20 years later; we now recognize the
Lobachevskian geometry accepts Euclidean postu- dissociation as loss of electrons). Lockyer was also
lates, except the fifth, and occurs on a curved sur- interested in archaeology, pioneering the study of
face with two lines always meeting in one direction possible astronomical alignments with ancient
and diverging in the other. The angles of a triangle structures. He founded the Science Museum in
no longer add up to two right angles but sum to less London and also the science journal Nature, of
than that. Lobachevski’s work was only widely which he was editor for 50 years.
accepted as important when Einstein’s general He was a fearless fellow, in debate and as an expe-
theory of relativity showed that the geometry of dition leader in pursuit of solar eclipses, and he was
space-time is non-Euclidean; it also prepared the a founder of solar astrophysics.
Lodge, Sir Oliver (Joseph) (1851–1940) British
way for the systematic exploitation of non-Euclidean
geometry by Riemann and Klein. Euclidean geome- physicist: pioneer of radio telegraphy.
try is now seen as a special case, adequate for all Lodge was born in Penkhull in the Potteries, in
everyday purposes, within a more general system. Staffordshire, where his father was a supplier of
Lockyer, Sir (Joseph) Norman (1836–1920) Bri- pottery materials. The family was prolific; Oliver
tish astronomer: discovered helium in the Sun. Lodge had 12 children, he was the eldest of 9, and
As a young civil servant at the War Office, Lockyer his thrice-married grandfather had 25 children.
developed an interest in astronomy and made it his After working for his father for 7 years, he studied
career. He was particularly interested in the Sun physics at the Royal College of Science and at
and in the use of the recently-introduced methods University College, London. In 1881 he was appointed
of spectral analysis. Following the eclipse of 1868 professor of physics at Liverpool, and in 1900 became
Lockyer discovered, independently of the French the first principal of the University of Birmingham.
astronomer P Janssen (1824–1907), that solar Lodge performed early experiments in radio,
prominences could be seen with a spectroscope at showing in 1888 that radiofrequency waves could
any time, not merely during eclipses, and that the be transmitted along electric wires. Simultaneously,
forms of the prominences slowly changed with however, Hertz demonstrated that such waves
time. He identified an unknown element in the could be transmitted through air, establishing the
Sun’s spectrum, which he named helium and basis for radio communication and somewhat over-
which was subsequently isolated in the laboratory shadowing Lodge’s work. Lodge went on, however,
by Ramsay in 1895. In 1873 he proposed that some to make useful technical advances, designing an
Loeffler, Friedrich August

improved radio detector (based on the drop in resis- The 10th and last child of an Irish postmaster,
tance of some metallic powders when exposed to Kathleen Yardley came to London when she was 5
electromagnetic radiation) and demonstrating a and graduated there in physics when she was 19.
form of radio telegraphy in 1894. He was the first For 20 years she worked at the Royal Institution,
person to attempt to detect radio waves from celes- and for the next 20 at University College, London,
tial objects. In the 1880s the Michelson–Morley developing methods pioneered by the Braggs for
experiments had shown that the ‘ether’ did not finding molecular structure by X-ray diffraction of
exist unless it moved with the Earth, but in 1893 crystals. In 1929 she worked out her first structure
Lodge devised an ingenious experiment that of great interest to organic chemists: it was that of
demonstrated that even a stationary ether did not hexamethylbenzene and her work showed that its
exist. In later years he devoted much effort to the benzenoid ring is a flat and regular hexagon of
scientific investigation of extrasensory perception carbon atoms, whose carbon–carbon bond lengths
and psychic phenomena. she measured. Some 2 years later she worked out
His interest in spark phenomena led him to the structure of hexachlorobenzene using (for the
greatly improve the early internal combustion first time) Fourier analysis to solve the structure;
engine for motor cars by his invention of the spark the method was to become the major technique
plug to ignite the mixture; two of his sons set up a used by her and others. When she began her work
company to manufacture it. (Portrait on p. 24) on organic structures, she ‘knew no organic chem-
Loeffler, Friedrich August [loefler] (1852–1915) istry and very little of any other kind’; but her
German bacteriologist. results were of great value to organic chemists, as
Educated in medicine in WĂĽrzburg and Berlin, was her work on the physics of crystals, which gave
Loeffler became an assistant to Koch in the 1880s. reality to the concept of molecular orbitals.
Bacteriology was then a young science; pure cul- A passionate pacifist and Quaker, Lonsdale
tures were difficult to secure and new techniques refused in 1939 to register for civil defence or any
were needed. In 1884 Loeffler devised a new other national service, and in 1943 she was fined ÂŁ2
medium (thickened serum) in which he was able to for the omission; refusing to pay, she spent a
culture the bacillus of diphtheria, then a major month in prison. In 1945 the Royal Society agreed
killing disease especially of children. He had previ- to elect women Fellows, and with Marjory
ously discovered the organism responsible for glan- Stephenson she became one of the first two female
ders (a contagious disease, mainly of horses). Fellows of the Royal Society.
Lorentz, Hendrik Anton [lohrents] (1853–1928)
In 1898, with P Frosch (1860–1928), he showed
that foot-and-mouth disease could be passed from Dutch theoretical physicist: contributed greatly to
one cow to another by inoculation with a cell-free the theory of the electron and of electromagnetism.
extract. This demonstration that a disease of ani- Lorentz completed his studies early at Arnhem
mals is due to a virus was a basic step in the found- and Leiden; a thesis on light reflection and refrac-
ing of virology; it followed the discovery, by others, tion won him the first chair of theoretical physics
of viral diseases of plants. Soon after Loeffler’s in Holland at Leiden when he was 24. In 1912 he
work, Reed showed that yellow fever is a viral became director of the Teyler Institute, Haarlem.
disease, transmitted by mosquitoes. He did a great deal to found theoretical physics as
London, Fritz Wolfgang (1900–54) German–US an academic discipline in Europe.
physicist: discovered the London equations in Lorentz’s thesis showed how to solve Maxwell’s
superconductivity. equation when an interface between two materials
Fritz and Heinz (1907–70) London were the sons is present. He was then able to predict the Fresnel
of a mathematician at Bonn and became known formula for the behaviour of light in a moving
for contributions to superconductivity published medium. In 1892 his ‘electron theory’ was pub-
together. Fritz studied classics, and did research in lished; it regarded electrons as embedded in the
philosophy leading to a doctorate at Bonn. Later he ether, which transmitted Maxwell’s electromag-
was attracted by theoretical physics, worked with netic fields and obeyed an additional relation for
Schrödinger at Zürich in 1927 and published on the force of the field on the electron (1895), now
the quantum theory of the chemical bond with W known as the Lorentz force. The Lorentz force was
Heitler (1904–81). In 1930 he calculated the non- proposed independently by Heaviside (1889).
polar component of forces between molecules, now Lorentz showed, by averaging microscopic forces
called van der Waals or London forces. Having fled on electrons to give macroscopic forces on materi-
from Germany in 1933 the brothers did research in als, how Maxwell’s ‘displacement current’ arises
F E Simon’s (1893–1956) group at Oxford. They soon and why an additional term is needed. These
published major papers on superconductivity, results were later confirmed by experiment.
giving the London equations (1935). Fritz moved to Lorentz adopted the word ‘electron’ in 1899, and
Duke University in the USA and continued to work identified electrons with cathode rays. He showed
on superconductivity and on the superfluidity of how vibrating electrons give rise to Maxwell’s elec-
helium (see Kapitsa). tromagnetic waves, and with Zeeman explained
Lonsdale, Dame Kathleen, née Yardley (1903–71) the Zeeman effect whereby atomic spectral lines
British crystallographer: applied X-ray diffraction are split in the presence of magnetic fields (1896).
analysis to organic crystals. For this work Lorentz and Zeeman were awarded
Lorenz, Edward


In the traditional world of Newtonian physics, Electrocardiograph showing fibrillation in human
dynamical systems are described by equations which heart ventricles. Long thought to be fully chaotic, in
1998 it was shown in dogs that there is some pattern
allow the future motion of an object to be predicted
and order in the electrical activity at the surface of
with great certainty. For example, the movement of
the affected heart.
the planets can be reliably computed years ahead to
within a fraction of a second. For centuries it was
assumed that the dynamics of all systems were inher- field throughout geological history. In biology,
ently calculable, even if some are so complicated as cardiac arrhythmias and erratic nerve impulses are
to be beyond our practical computational ability. chaotic, and in astronomy, once the showpiece of
Contrary to intuition, however, there are many Newtonian physics, the motion of some objects is
natural systems whose motion turns out to be inher- now known to be chaotic, such as the moon
ently chaotic. The first example of such a system to be Hyperion, which orbits Saturn in an unpredictable
recognized as such was the weather, or rather equa- tumbling motion. Turbulence is a classic example,
tions used to model it. These never settle into a as are wildlife populations, which undergo
steady state, but constantly vary in an aperiodic, unpredictable cycles.
apparently random manner. E LORENZ showed that Chaos has been defined as the irregular,
they also exhibit an extreme dependency on their unpredictable behaviour of deterministic, nonlinear
initial conditions, a factor that makes long-range dynamical systems. As such, fractals (see MANDEL-
weather forecasting effectively impossible. BROT) are highly visual examples of chaotic systems,
Many other phenomena in all branches of science where apparently simple shapes are seen, upon
have since been recognized to be chaotic. Examples closer inspection, to reveal an infinity of detail on
are the motion of a simple dynamo, which can progressively finer scales.
undergo unpredictable reversals and which may
model the erratic reversals of the Earth’s magnetic

the 1902 Nobel Prize for physics. So successful was After serving as a meteorologist in the US Army
the ‘electron theory’ that its failure to explain the Air Corps during the Second World War, Lorenz
photoelectric effect (see Lenard, and Einstein) was was one of the first to develop numerical models of
a major clue to the need for quantum theory. the atmosphere and to use computers for weather
Lorentz studied the result of the Michelson– forecasting. He demonstrated the inherent impos-
Morley experiment, which gave no indication that sibility of long-range forecasting, and helped found
the Earth was moving through the hypothetical the study of chaos.
ether. He showed that if moving bodies contracted Lorenz observed that minute differences in the
very slightly in the direction of motion, the initial conditions of his numerical models of the
observed results could occur. Derived indepen- atmosphere could, after a relatively short time,
dently by FitzGerald, this is known as the Lorentz– lead to radically different outcomes. He realized
FitzGerald contraction. In 1904 Lorentz developed that the differential equations used to describe
a firm mathematical description of this, the atmospheric behaviour, while deterministic, were
Lorentz transformation, and this was later shown also highly dependent on initial conditions and
by Einstein to emerge naturally out of his special that this limited the usefulness of practical
relativity theory (1905). weather forecasts to about a week. This phenome-
Lorenz, Edward (Norton) [lorens] (1917– ) US non has become known as the butterfly effect, from
meteorologist. the idea that the small air movement caused by a
Lorenz, Konrad

butterfly flapping its wings in one part of the globe compound, that ozone is O3, that benzene is cyclic
could in theory result in a storm weeks later thou- and that double and triple bonds can usefully be
sands of miles away. shown as connecting lines. He assumed variable
He went on to investigate other examples of valences for some atoms (eg 2, 4 or 6 for sulphur)
chaotic behaviour, establishing in 1963 that even but fixed values for C (4), O (2) and H (1). His book
very simple deterministic systems can show had little influence, and Loschmidt moved to work
chaotic behaviour. One of his examples was the on the kinetic theory of gases; he calculated the
motion of a waterwheel, which, as he demon- first accurate value for the size of air molecules.
strated, becomes unpredictable and prone to From this he calculated in 1867 the number of mol-
ecules of gas per cm3, but his value is about 30 times
random reversals in direction when the rate of
water flow exceeds a threshold value. In order to too small. However, for this pioneer attempt to
illustrate the chaotic dynamics of such systems, obtain a value for the Avogadro constant NA, the
Lorenz devised the Lorenz attractor, a three-dimen- constant is sometimes named as the Loschmidt
sional curve in which the location of a point repre- number (L); Avogadro never gave any pertinent
sents the motion of a dynamical system in phase numerical calculations on this.
Lovell, Sir (Alfred Charles) Bernard (1913– )
space. The curve shows how the motion of the
system oscillates aperiodically between the two British physicist: pioneer radio astronomer.
directions and never settles into a steady state. After studying physics at the University of Bristol,
Lorenz, Konrad (Zacharias) [lohrents] (1903–89) Lovell was appointed to the staff of the physics
Austrian ethologist: a founder of modern ethology. department at the University of Manchester in
A surgeon’s son, Lorenz studied medicine in New 1936, where he was to spend his career. He became
York and Vienna and graduated in 1928. professor of radio astronomy and later director of
Afterwards he taught anatomy in Vienna but by the the Nuffield Radio Astronomy Laboratories at
mid-1930s his interest had moved to animal psy- Jodrell Bank, near Manchester.
chology; in fact he had collected animals and Lovell was an outstanding experimental physicist
recorded their habits from childhood. In the late who played a key part in the wartime development
1930s he made close studies of bird colonies, and in of radar in Britain, and went on to pioneer the
1935 described ‘imprinting’. An example of this is study of radio astronomy, constructing the world’s
the way a young bird regards the first fair-sized largest steerable radio telescope at Jodrell Bank.
moving object it sees as a representative of its After early university work on the detection of
species. This is usually a parent, but Lorenz showed cosmic ray showers with Blackett, Lovell was con-
it could be a model, a balloon, a tractor or a human scripted to the war effort in 1939 and worked on
being. In Lorenz’s view, much behaviour is geneti- the development of airborne radar systems to
cally fixed or innate; this was in conflict with the enable British nightfighters to locate German
ideas of most psychologists of the 1930s, who saw bombers. This was highly successful and resulted in
behaviour as entirely flexible or learned. Their heavy casualties being inflicted on the bombers,
emphasis was on laboratory experimentation on saving many lives. In 1942 he was directed to take
animal learning, while Lorentz valued studies of charge of the development of a radar system to help
species-specific behaviour in the wild. In 1942 he bombers locate their targets by ground returns,
joined the German army (as a motor cycle instruc- thus greatly increasing the effectiveness of Allied
tor and then as a psychiatrist), was captured and bombing raids against Germany. In March 1943 a
spent 4 years as a prisoner in the USSR (he studied modification of the system enabled aircraft to
the courtship rituals of his fleas). Later, working in detect German U-boats at night, again with great
Austria, he continued his studies on birds and success, dramatically reducing Allied shipping
other animals, and his generalizations did much to losses in the Atlantic.
found ethology as a particular branch of animal After the war Lovell returned to Manchester;
behaviour study. Lorenz has been criticized for his between 1946 and 1951 he used war surplus radar
emphasis on innate patterns and for his extrapola- equipment to detect meteors via their ionized trails
tions from animals to man. His views on human in the upper atmosphere. He made two significant
aggressiveness, population expansion and environ- discoveries: first, that many hitherto unknown
mental deterioration are pessimistic. He shared a meteor showers occur during daylight hours, often
Nobel Prize in 1973 with Tinbergen and Frisch. exceeding the known seasonal showers in number
Loschmidt, Johann Joseph [lohshmit] (1821–95) and intensity; second, by measuring meteor veloci-
German physical chemist: early worker on valence ties using the radar he showed that their orbits
theory and on molecular size. were ‘closed’ (ie confined to the solar system) and
Born into a peasant family in what is now the that the meteors were therefore not of interstellar
Czech Republic, Loschmidt studied in Prague and origin, as had been suggested.
Vienna. In the 1840s he tried to establish himself in In 1947 Lovell completed the construction of a
business but the times were difficult and in 1854 he 218 ft (66 m) aperture fixed parabolic aerial. This
became bankrupt. He taught science in Vienna, and aerial was used to detect the radio emission from
became a friend of Stefan. His book Chemical Studies the Andromeda galaxy in 1951 by R Hanbury-Brown
I (1861; there was never a Part II), included some (1916– ) and C Hazard. This work stimulated the
novel and correct ideas: that sugar is an ether-like plans made by Lovell in 1949–50 for what is
Lowell, Percival

undoubtedly his greatest and most lasting contri-
bution to science, the building of a 250 ft (76 m)
diameter steerable parabolic radio telescope. The
actual building of the telescope became a cause
célèbre of British science, greatly exceeding original
cost and time estimates. Although Lovell was criti-
cized for this, the Jodrell Bank telescope was break-
ing new ground as the first ‘big science’ project; it
required large funding but it has been used by
numerous teams of scientists for studying a wide
range of phenomena for many years. Today, such
projects are often funded on an international basis
and are administered by sizable committees.
In 1957, almost before it was completed, the
Jodrell Bank telescope caught the public imagina-
tion by tracking the carrier rocket of the world’s
first artificial satellite, Sputnik. In 1959 the tele-
scope measured the descent of Lunik 2 to the
impact on the Moon and in 1966 recorded the first
photographs of the lunar surface transmitted by
the Russian Luna 9 probe. Although the telescope
was used in the radar mode for studies of the Moon
and measurement of the distance of Venus, the
emphasis has been on radio astronomy. The identi- James Lovelock
fication of radio sources with optical objects was an
early goal and this led directly to the discovery of to regulate the environment and maintain optimal
the objects that became identified as quasars in conditions for life. According to the Gaia hypothe-
1963. Much of the early work on pulsars followed sis, therefore, life on Earth is bountiful not by
and the gravitational lens effect for quasars was dis- chance but because the Earth’s feedback mecha-
covered in 1979. Lovell’s own research with the tele- nisms have evolved a complex and interwoven pat-
scope led to the discovery of the radio emission tern of life that not only makes optimal use of the
coincident with the optical flares on the red dwarf environment but also transforms the environment
stars. into a state that best supports life.
While Lovell’s personal scientific achievements While the Gaia hypothesis is, through its global
were noteworthy, his lasting impact on science has and all-embracing nature, difficult to ‘prove’, it is a
been through his administrative and political way of viewing the Earth that has proved fruitful.
efforts, which led to the building of the great scien- One result was Lovelock’s own prediction of
tific instrument that today bears his name. oceanic dimethyl sulphide emissions in order to
Lovelock, James (Ephraim) (1919– ) British en- balance the global sulphur cycle, which has since
vironmental scientist: devised the Gaia hypothesis. been observationally confirmed, as have his pro-
After studying chemistry and medicine in posals on aspects of the carbon cycle in nature.
England, Lovelock held medical research positions Lovelock’s inventions and theories have signifi-
in the UK as well as posts in chemistry, medicine cantly contributed to the advancement of the envi-
and space science in the USA. After 1964 he con- ronmental sciences and have increased awareness
ducted an independent scientific career. Lovelock’s of the global effects of man’s polluting activities.
most significant contributions have been in the Early scepticism about the Gaia hypothesis has
field of environmental science. diminished as its value has been appreciated.
Lowell, Percival (1855–1916) US astronomer: pre-
In 1957 Lovelock invented the electron capture
detector, an extremely sensitive device that revolu- dicted existence and position of Pluto.
tionized the study of environmental chemistry by Son of a wealthy Boston family, Lowell travelled
enabling man-made chemicals to be detected in the extensively after graduating from Harvard. His
environment in very low concentrations. The device sister Amy was a major poet and his brother
led to the discovery that pesticide residues had became president of Harvard. Lowell’s interest in
become widely distributed in nature, and also to the astronomy was first stimulated by Schiaparelli’s
discovery of significant concentrations of chloroflu- report in 1877 of ‘canali’ on Mars. He became con-
orocarbons and nitrous oxide (N2O) in the atmos- vinced that Mars was inhabited by an intelligent
phere, both discoveries leading to increased concern race and wrote books on the subject. At the begin-
about mankind’s pollution of the environment. ning of this century such views were not so ridiculous
In the early 1970s Lovelock proposed the theory as they appear today, and the excellent observatory
for which he is best known, the Gaia hypothesis. he built in Arizona in 1894 at a height of 2200 m
Named after the Greek Earth goddess, it proposes became an important centre for planetary studies.
that the Earth can be viewed as a single living However, Lowell’s most important contribution was
system in which complex feedback mechanisms act the prediction (based on its gravitational influence
Lower, Richard

on Uranus), of a ninth planet beyond Neptune. colonies in a movable glass-sided container. His
Although he himself searched for it from 1905 until methods (including the first use of paint-marking
1914, Pluto was not detected until 1930 by of insects for their identification, and obstacles and
Tombaugh, working at Lowell’s own observatory. It mazes to test intelligence) led to much new knowl-
was named after the Greek god of outer darkness. edge of their habits, instincts and intelligence.
Lower, Richard (1631–91) English physiologist: With a device designed for him by Galton he
made first successful direct blood transfusion. showed that ants can distinguish colours and see
Lower qualified in medicine at Oxford, where he ultraviolet light; and he discovered bees’ colour
assisted his teacher Willis with dissections, and preferences.
then moved to London to practise; he was an early He became well-known as an MP by introducing
Fellow of the Royal Society and had belonged to the bills, on Bank Holidays (‘St Lubbock’s Days’, in 1871),
Oxford group that founded it. In Oxford in 1665 he also on wild bird protection, open spaces, ancient
demonstrated transfusion of blood from the artery monuments and dozens more. He belongs to the
of one dog to the vein of another. Pepys in his diary rare group, including Franklin, distinguished in
for 1667 reports on a successful human blood trans- science, politics and commerce. Few later amateur
fusion performed as a Royal Society experiment by scientists can compete with that distinction.
Ludwig, Karl Friedrich Wilhelm [ludveekh]
Lower: ‘I was pleased to see the person who had his
blood taken out. He speaks well … and as a new (1816–95) German physiologist: pioneer of modern
man.’ This was probably the first human blood physiology.
transfusion in the UK. Later attempts by others to Ludwig enrolled as a medical student in Marburg
transfuse from animals to humans led to some in 1834, but he had a stormy student career. He
deaths, and only after Landsteiner’s work from soon had a heavily scarred lip through duelling,
1900 on blood groups did human transfusion and conflict with the university authorities sent
become useful. Lower’s Treatise on the Heart (1669) him to study elsewhere; but he returned to
gives a good account of the structures of the heart. Marburg in 1840 and was teaching there by 1846.
He recognized that it is not ‘inflated by spirits’ but Later he taught in ZĂĽrich, Vienna and Leipzig. His
acts as a muscular pump, with systole as the active work helped to create modern physiology; he saw
phase and diastole a ‘return movement’. He studied no place for ‘vital force’ and he sought explana-
the colour change between dark venous blood and tions of living processes in terms of physics and
red arterial blood, experimented with dogs and chemistry. In this he was much influenced by his
deduced that the red colour results from mixing friend, the chemist Bunsen. When Ludwig began,
the dark blood with inspired air in the lungs; he physiology had few experimental instruments. He
realized that the purpose of respiration is to add developed the kymograph (1846) and used it to dis-
something to the blood. After 1670 he concentrated cover much about respiration and the circulation;
on his medical practice. he devised the mercurial blood pump (1859), the
Lubbock, (Sir) John, Baron Avebury (1834–1913) stream gauge (1867) and a method of maintaining
British biologist: contributor to archaeology, ento- circulation in an isolated organ, perfusion (1865).
mology and politics. His blood pump allowed the study of blood gases
Lubbock’s father was a successful banker and and respiratory exchange. Later he worked on the
amateur mathematician, and the boy joined the action of the kidneys and the heart, on salivary
family bank at 15. He was successful enough, but secretion and on the lymphatic system. During 30
his main interest was in biology, in which he was years he and his students did much to create
self-taught. Fortunately he could concentrate fully modern physiology and when he died almost every
on different matters at short intervals, and in his leading physiologist had at some time studied with
adult life banking, biology, politics and education him.
Lummer, Otto [lumer] (1860–1925) German physi-
all engaged him. He was lucky that Darwin lived
near the family home, made a friend of the boy and cist: experimentalist on black body radiation.
developed and used his talent for drawing. Lubbock After a period as assistant to Helmholtz, in 1904
early became an enthusiast for Darwin’s ideas and Lummer became professor at Breslau. His early
helped to expound them, and he was one of the few work was on photometry and later he worked on
men whose opinions mattered to Darwin. spectrometry, but his best-known work is on radi-
In 1855 he found the first fossil musk-ox in ant heat. Since a black body approximates to a per-
Britain, which gave early evidence of an ice age. In fect absorber, it follows that a black body should
the 1850s and 1860s he began to link ideas on evo- form an ideal radiator; but this at first seemed to be
lution with studies in archaeology and human pre- an abstract concept. However, in the 1890s Lummer
history and he travelled widely in Europe to study and Wien realized that a small aperture in a hollow
lake village sites and tumuli there. He coined the sphere heated to the required temperature should
words ‘neolithic’ and ‘palaeolithic’ for the New and be equivalent to a black body at the same tempera-
Old Stone Ages. His books on prehistory were pio- ture. Experimental work on this basis was carried
neers in the field, but his work here did not out with Wien and later with E Pringsheim on the
obstruct another of his pursuits, entomology. He distribution of energy in black body radiation, and
worked especially on the social insects, and devised was important in leading to Planck’s quantum
the ‘Lubbock nest’, in which he could examine theory of 1900.
Lyot, Bernard Ferdinand

geological features that he had discovered on his
extensive travels through Europe and America.
This classic work greatly influenced Darwin in
developing his theory of evolution, a concept which
Lyell, strangely enough, never accepted.
Lyon, Mary Frances (1925– ) British geneticist.
After graduating from Cambridge in 1946 and
taking a doctorate there in 1950, Mary Lyon joined
the Medical Research Council’s Radiobiology Unit
at Harwell, leaving it as Deputy Director in 1990.
Her extensive work on mouse genetics led to better
knowledge of the mammalian genome, the prob-
lems of inherited disease and the genetic risks of
low radiation exposure. The ‘Lyon hypothesis’ of
1961 proposed that one of the two X chromosomes
Charles Lyell
in female mammals can be randomly inactivated,
Lyell, Sir Charles [liyl] (1797–1875) British geolo- so that the females become mosaics of different
gist: established the principle of uniformitarian- genetic cell lines. This idea has been confirmed and
ism in geology. is important in chemical genetics and in genetic
Lyell at first embarked on a legal career, but his imprinting.
Lyot, Bernard Ferdinand [lyoh] (1897–1952) French
interest in geology led in 1823 to his appointment
as secretary of the Geological Society of London. astronomer: invented the coronagraph.
During the first part of the 19th-c geology had Lyot worked at the Paris Observatory at Meudon
made great advances in the collection of informa- from 1920. He invented the coronagraph, a device
tion, but most geologists still believed in one or that allows the Sun’s corona to be observed without
more world-wide ‘catastrophes’ to account for the the necessity for a total solar eclipse, in 1930. This
creation of what they found. Lyell was responsible is achieved by creating an artificial eclipse inside a
for the general acceptance of the principle of uni- telescope with very precisely aligned optics. Rocket-
formitarianism, the idea that rocks and geological borne solar observatories such as Skylab have, in
formations are the result of the ordinary processes the last 20 years, allowed coronagraphs to be used
that go on every day, but acting over very long peri- outside Earth’s atmosphere, adding much to know-
ods of time. This principle was first advocated in a ledge of the corona.
general way by Hutton, but was much more con- Lyot also pioneered the study of the polarization
vincingly illustrated and argued by Lyell. In 1830 he of light reflected from the surface of the Moon and
published his popular Principles of Geology, in which of the planets, allowing him to infer something of
he applied his ideas in explaining many of the their surface conditions.

MacArthur, Robert Helmer (1930–72) Canadian- cal movement of DNA from site to site. When she
–US ecologist: developed theories of population presented the work at a symposium in 1951 the sig-
biology. nificance and implications were not understood,
Born in Canada, MacArthur moved to the USA and her discoveries were neglected by most geneti-
when he was 17 and studied mathematics at uni- cists for many years. Disappointed, she stopped
versity, moving to Yale for his doctorate. However, publishing the results of her continuing experi-
in the second year of his PhD work he changed to ments. One aspect of McClintock’s work, on pro-
zoology. After 2 years military service he returned motor and suppressor genes, was to be much
to Yale and then concentrated on ecology. From extended by Monod in the 1960s.
1965 until his early death from cancer he was pro- In the 1970s a series of experiments by molecular
fessor of biology at Princeton. His first research was biologists proved that pieces of bacterial DNA
on five closely similar species of warbler which co- do indeed ‘jump’ on the chromosomes, and
exist in the New England spruce forest and which McClintock’s work was finally recognized. She was
were thought to violate the competitive exclusion awarded the first unshared Nobel Prize for physiol-
principle, ie that in ‘equilibrium communities’ no ogy or medicine to be given to a woman, in 1983.
two species of the same animal occupy the same Watson described her as one of the three most
niche. He found that the birds tend to occupy dif- important figures in the history of genetics. Asked
ferent parts of the trees and that the principle was if she was bitter about the lack of recognition of her
followed. From then on, he studied population biol- work, McClintock answered ‘If you know you’re
ogy and the strategies used to form multi-species right you don’t care. You know that sooner or later
communities. He devised ways to quantify ecologi- it will come out in the wash.’
MacDiarmid, Alan G (1927– ) US chemist: devel-
cal factors and to predict mathematically the level
of diversity of bird species in a given habitat. His oper of electrically conducting organic polymers.
ideas have proved influential, including his divi- Born in New Zealand, MacDiarmid studied chem-
sion of animals into r and K species. The r species istry there and at Wisconsin and Cambridge before
are opportunistic, with high reproductive rates, making his career at the University of Pennsylvania
heavy mortality, short lives and rapid develop- at Philadelphia from 1955.
ment. The K-strategists are larger, develop more In 1973 he was working with poly(sulphur
slowly and are more stable; and he was able in 1962 nitride), a bronze solid consisting of chains of sul-
to show that natural selection principles apply to
both groups.
McClintock, Barbara (1902–92) US plant geneticist
and discoverer of ‘jumping genes’.
Barbara McClintock’s early success in science at
school disappointed her mother, who thought that
her daughter was not developing ‘appropriate fem-
inine behaviour’. She graduated from Cornell and
had early success in her postgraduate work; she
found she could identify individual maize chromo-
somes under the microscope, which led to the
integration of plant-breeding experiments with
chromosomal analysis. She gained her PhD in 1927
and soon became recognized as a leading scientist
in her field. Failing to get professional advance-
ment, she left Cornell and went to the University of
Missouri in 1936. Promotion still eluded her and in
1941 she went to work at the Cold Spring Harbor
Laboratory, where she discovered and studied a
class of mutant genes in maize. Her experiments in
maize genetics led her to the very novel idea that
the function of some genes is to control other
genes; and that some are able to move on the chro-
mosome and control a number of other genes. This
concept of ‘jumping genes’ is now familiar and
accepted, even though it is far from fully under-
stood; as she demonstrated, it must involve physi- Alan MacDiarmid
McLaren, Anne Laura

phur and nitrogen atoms, –(SN)n– which conducts abstract and untestable models and concepts, and
like a metal, in collaboration with Alan J Heeger that science should discard anything that was not
(1936– ) a US physicist then also working at observable. Mach argued that all information
Philadelphia. Also in the 1970s Hideki Shirakawa about the world comes through sensations, and
(1936– ), a Japanese chemist at Tsukuba, Japan, that the world consists of data; that which may not
found a new way of making polyacetylene –(CH)n– be sensed is meaningless. A historical view of sci-
which is a plastic and a semiconductor. The two ence also convinced Mach that discoveries are
teams worked together from 1975, and soon found made in many ways, not particularly related to the
that doping the polyacetylene with a small amount scientific method, and that accidents and intuition
of iodine enhanced the conductivity by a factor of play a role. Mach influenced the authors of quan-
many millions, comparable with copper or silver. tum mechanics, particularly the ‘Copenhagen’
This discovery in 1977 of the first conducting school of Bohr, and the theory sharply distin-
organic polymer has led to exploration of a range of guishes between observable quantities and the
new uses in antistatic films and fabrics, and in dis- abstract mathematical wavefunction from which it
play and detection screens and polymer-based elec- is derived and which has a higher information con-
tronic circuits which can be smaller and cheaper tent. Mach and his book Mechanics (1863) greatly
than existing inorganic (usually silicon) components. influenced Einstein. What is now known as Mach’s
MacDiarmid, Heeger and Shirakawa shared the principle states that a body has no inertial mass in
Nobel Prize for chemistry for 2000 ‘for the discov- a universe in which no other mass or bodies are pre-
ery and development of conductive polymers’. sent, as inertia depends on the relationship of one
Macewen, Sir William [muhkyooan] (1848–1924) body to another. Einstein’s efforts to put this on a
British surgeon: pioneer of aseptic surgery, neuro- sound footing led to his theory of relativity. This
surgery and orthopaedic surgery. result was not to Mach’s liking and he rejected it.
Macewen was very much a Glaswegian, graduat- Mach also did some experimental work, and
ing there in 1869 and afterwards working there investigated vision, hearing, optics and wave phe-
until his death. He was a student under Lister at nomena. In 1887 he published photographs of pro-
the time antiseptic methods were started in the jectiles in flight showing the accompanying shock
Glasgow Royal Infirmary, but he soon modified waves; he found that at the speed of sound the flow
these methods and became a pioneer of aseptic of a gas changes character. In supersonic flow, the
techniques, giving up the carbolic spray by 1879 Mach angle is that between the direction of motion
and using boiling water or steam to sterilize gowns, of a body and the shock wave. In 1929 the Mach
dressings and surgical instruments. A full surgeon number was named as the ratio of the projectile
by age 28, his forceful personality allowed him to speed to the speed of sound in the same medium. At
impose rigorous aseptic routines, and his surgery Mach 1, speed is sonic; below Mach 1, it is subsonic;
was bold and effective. In the 1880s he operated on above Mach 1, it is supersonic.
Mackenzie, Sir James (1853–1925) British cardiol-
abscesses and tumours of the brain with success;
surgery of the skull was ancient, but work on the ogist: developed instrumental methods for study of
brain was novel and called for skilful diagnosis and heart disease.
localization and precise surgery. In 1893 he Mackenzie was an Edinburgh medical graduate
reported on 74 brain operations; 63 succeeded. At who did most of his work in Burnley, Lancashire.
the same period he developed successful bone Following the unexpected death of a pregnant girl
surgery, including bone grafts. His interest in bone from a heart attack, he began to keep regular
growth led to his work on the growth of deer detailed records of heart action. For this he devised
antlers, published when he was over 70; he devised improved instruments to record ink-tracings on
methods and instruments for corrective bone paper of the pulses in arteries and veins, which he
surgery on acute deformities such as those resulting correlated with heart action. He soon found that
from rickets, then common in Glasgow children. some irregularities of rate and rhythm were
Mach, Ernst [mahkh] (1838–1916) Austrian theoret- common and appeared unrelated to disease (previ-
ical physicist: fundamentally reappraised the phi- ously all such disorders were thought to be signs of
losophy of science; ‘the father of logical positivism’. disease), while other arrhythmias did point to dis-
Mach was mainly educated at home until age 15, ease. His book Diseases of the Heart (1908) described
but later studied at Vienna. There he became inter- his polygraph and its use, and was a milestone in
ested in the psychology of perception as well as in cardiology. His recognition that advanced mitral
physics. An appointment as professor of mathe- valve disease leads to auricular fibrillation was a
matics at Graz followed (1864), and he later moved step towards its later treatment. He did much to
to Prague (1867) as professor of experimental reintroduce digitalis as a heart drug; it had been
physics and to Vienna in 1895 as a professor of phi- used by Withering but had fallen into disfavour
losophy. A slight stroke in 1897 caused partial because the dose needs careful regulation. The
paralysis and he had to retire from the university in chemically pure digoxin gives much better control
1901. Thereafter for 12 years he was a member of and is widely used.
McLaren, Anne Laura (1927– ) British geneticist.
the upper chamber of the Austrian parliament.
The theme of Mach’s work was his belief that As a daughter of Lord Aberconway, horticultural-
science, partly for historical reasons, contained ist and a creator of the famous garden at Bodnant
McMillan, Edwin Mattison

in North Wales, Anne McLaren might have been nium (number 94), but in 1940 he moved to defence
expected to work in botany. In fact she studied zool- work on radar and sonar and the new transuranic
ogy at Oxford and afterwards specialized in devel- elements were studied by Seaborg, with con-
opmental biology and genetics at London and tinuing success. For their work on this Seaborg
Edinburgh. From 1974–92 she directed the Medical and McMillan shared the 1951 Nobel Prize for
Research Council’s Mammalian Development Unit chemistry.
in London, working mainly in embryology and Lawrence’s cyclotron had met a limit to its per-
using mice. For example, she showed that a cell formance in the early 1940s; particles accelerated
type from the testes of mice embryos can develop to in it above a certain speed increased in mass in
give a variety of cell types in culture, depending on accord with Einstein’s theory of relativity and this
its environment. Such work has implications in sex put them out of phase with the electric impulses.
determination in germ cells, in IVF, in twinning McMillan in 1945 devised a solution to this by use of
and in the development of malignancy. She became a variable frequency for the impulses, adjusted to
a Fellow of the Royal Society in 1975, and in 1991 its keep in phase with the particles. This machine, the
foreign secretary, a major post in British science; synchrocyclotron, could be designed to give results
she was the first woman to become an officer of the up to 40 times more powerful than the best
Society. She has been a leading and successful cyclotrons.
Magendie, François [mazhãdee] (1783–1855)
advocate for continuing research in the controver-
sial field of human embryology. French physiologist: pioneer of experimental phar-
McMillan, Edwin Mattison (1907–91) US physi- macology.
cist: discoverer of neptunium. Magendie graduated in medicine in Paris in 1808,
Educated at Caltech and Princeton, McMillan and afterwards practised and taught medicine
joined the University of California at Berkeley in there. In 1809 he described his experiments on
1935 and was there for the rest of his career. In the plant poisons, using animals to find the precise
late 1930s he was mainly concerned with nuclear physiological effect and then testing out the com-
reactions and the design of cyclotrons. pounds on himself. In this way he introduced into
In 1940 with P Abelson (1913– ) he showed that, medicine a range of the compounds from plants
when uranium is bombarded with neutrons, one now known as alkaloids, which contain one or more
nuclear reaction that occurs leads to formation of a nitrogen atoms within ring structures; many have
new element, the first discovered to be heavier striking pharmacological properties and Magendie
than uranium; it was named neptunium. The showed some of the medicinal uses of strychnine
nuclear reactions are: (from the Indian vomit-nut), morphine and codeine
(from opium) and quinine (from cinchona bark).
U + n → 239U + γ (gamma radiation)
92 92
Magendie’s studies were remarkably wide-ranging.
(an instantaneous reaction)
He showed in 1816 that protein is essential in the
and 239U → 239Np + e– (beta radiation)
92 93 diet, and that not all kinds of protein will suffice. He
(half-life of 239U = 23 min) studied emetic action; the absorption of drugs;
McMillan obtained evidence that the radioactive olfaction; and the white blood cells. In 1822 he
neptunium decayed to form a new element, pluto- showed that spinal nerves have separate paths con-
trolling movement and sensation, confirming and
extending C Bell’s work. His enthusiasm for vivi-
section sacrificed hundreds of animals, mainly
dogs, which was much disapproved in England (but
not in France); he pursued data, avoided theory and
did much to found the French school of experimen-
tal physiology.
He also made some major errors: he claimed that
cholera and yellow fever were not contagious, and
he was against anaesthesia (induced by ether) in
Maiman, Theodore Harold [miyman] (1927– ) US
physicist: constructed the first laser.
Maiman was the son of an electrical engineer
and, after military service in the US Navy, he stud-
ied engineering physics at Colorado University.
Later he did his doctorate in electrical engineering
at Stanford and joined the Hughes Research
Laboratories in Miami in 1955. The maser (produc-
ing coherent microwave radiation) had been
devised and induced to work by Townes in 1953,
and Maiman improved the design of the solid-state
version. He then constructed the first working laser
(Light Amplification by Stimulated Emission of
Ed McMillan in 1952
Panel: Superheavy chemical elements: a limit to the periodic table?

SUPERHEAVY CHEMICAL number of internuclear collisions and then survive for
ELEMENTS: A LIMIT TO such a short time as to render detection difficult, it
THE PERIODIC TABLE? seemed likely that a practical limit to the periodic table
must exist, perhaps near to the then-undiscovered
The chemical element with the heaviest atoms element 108. However, from the 1970s some theories
occurring in nature is uranium, with atomic of nuclear structure were developed that proposed
number 92. that relatively stable shells of protons and neutrons
The atomic number is the number of positively exist in the nucleus; and specifically that in the region
charged protons in the atomic nucleus. The remain- with atomic number 110–118 an ‘island of stability’
ing nuclear mass consists of neutrons, each with should allow superheavy nuclei with a detectable
nearly the same weight as a proton, but with no life-span to exist.
charge. In uranium most of the atoms have 146 neu- Experimental work on this basis was at first
trons, but about 0.7% have 143 neutrons. The rela- directed to the possibility of detecting a superheavy
tive atomic mass of the two kinds of atom will element in nature, but the search proved barren.
therefore be 238 or 235. Since the heavier sort of However, in the early 1980s at the Laboratory for
uranium atom predominates, the average relative Heavy Ion Research at Darmstadt, Germany, ele-
atomic mass of a quantity of uranium is close to 238. ments 107, 108 and 109 were made by nuclear syn-
Atoms with the same atomic number but different thesis, by bombarding the nuclei of bismuth or lead
atomic mass have the same chemical properties, but with relatively heavy nuclei of chromium or iron. Only
their nuclear properties – such as their radioactivity minute amounts of these elements were made and
if the nucleus spontaneously breaks down – are their nuclei quickly disintegrated; in the case of 109
different. They are known as ‘isotopes’ of that only a few atoms were detected and the radioactive
element: uranium exists therefore as two isotopes, half-life is a mere 3.4 ms. In 1994 the same team
uranium-235 and uranium-238. made element 110 by bombarding lead with atoms of
The first transuranium elements (ie those with an nickel-64, and element 111 by similar attack on a
atomic number above uranium, higher than 92) were bismuth-209 target. In each case only a few atoms of
neptunium (Np, 93) and plutonium (Pu, 94), made by the new element were detectable and they quickly
MCMILLAN and his co-workers in 1940 at the decayed. Firing zinc-70 at bismuth-209 gave element
University of California by bombarding uranium 112, but produced only two atoms in 24 days: its half-
nuclei with nuclear particles from a cyclotron or a life is 240 microseconds. A new isotope of element
linear accelerator. Later in the 1940s SEABORG and his 114 made in 1999 in Dubna has 114 protons and 173
colleagues made americium (Am, 95), curium (Cm, neutrons; its half-life of 5 s confirms the ‘island of
96), berkelium (Bk, 97) and californium (Cf, 98) by stability’ idea. Later in 1999 the Lawrence Livermore
essentially similar methods. Plutonium is used in Laboratory at Berkeley reported relatively stable
human heart pacemakers, and americium is used in isotopes of elements 116 and 118.*
household smoke alarms. Similar methods continue to be applied in the
When in 1952 the first hydrogen bombs were search for yet heavier elements; the problem is seen
exploded, the debris of a thermonuclear explosion by many physicists as among the most intriguing
was found to contain traces of two even heavier ele- targets in physics. Its resolution will continue to spur
ments, named as einsteinium (Es, 99) and fermium theorists in their efforts to refine the theory of nuclear
(Fm,100). Like all the transuranics, these elements structure, and experimentalists in their search for
are highly radioactive; evidently the mutually repul- more powerful particle accelerators and more sensi-
sive forces between the large number of nuclear tive detectors for possibly very short-lived super-
protons, even though diluted by neutrons, leads to heavy nuclei.
nuclear instability. The names of the heaviest elements have been the
Then, between 1955 and 1975 at the University subject of controversy. A widely used scheme
of California, still heavier nuclei were made, by commemorates major contributors to nuclear
bombarding heavy nuclei (californium in most cases) chemistry for element 104, rutherfordium; 105,
with nuclei from lighter elements (boron, carbon, dubnium (after Dubna, nuclear research centre near
nitrogen or oxygen). Moscow); 106 , seaborgium; 107, bohrium; 108,
In this way mendelevium (Md, 101), nobelium hessium; 109, meitnerium. But debate on these
(No, 102), lawrencium (Lr, 103), and the elements names continues.
with atomic number 104, 105, and 106 were made. The question remains: does the periodic table of
The last of these has a radioactive half-life of only the elements have an end? And if so, where is it?
0.9 s, supporting the view held until the early 1970s
that, as these elements are formed in only a minute
* The claim for 118 was retracted in 2001.

Malpighi, Marcello

Mandelbrot, Benoit (1924– ) Polish–French
partly-silvered mirror
ruby rod
mathematician: initiated the novel geometry of
silvered mirror metal holder
fractional dimensions and fractals.
Born into a Lithuanian-Jewish family, Mandel-
brot was educated at the École Polytechnique in
Paris, before visiting the USA and obtaining a
research position at IBM’s Thomas J Watson
Research Center. Mandelbrot’s uncle, Szolem, had
been a founder member of the innovative French
group of mathematicians who worked under the
collective name of Nicholas Bourbaki.
Mandelbrot’s career as an applied mathemati-
beam of red light
flash lamp
cian included teaching economics at Harvard, engi-
neering at Yale and physiology at the Einstein
Section through a ruby laser
College of Medicine. He worked on mathematical
linguistics, game theory and economics, before
Radiation) in the Hughes Laboratories in 1960, being asked to investigate the problems of noise on
although Townes and Schawlow had published a telephone wires used for computer communica-
theoretical description. A ruby crystal with mirror- tions. He discovered that, contrary to his intuition
coated cut ends was used and this resonant cavity that the noise would be random in timing, it
was stimulated by flashes of light to produce a occurred in bursts and that, as he studied these
coherent, highly monochromatic, pulsed laser bursts on shorter and shorter time scales, the dis-
beam. The first continuous wave (CW) laser was tribution of the noise spikes always remained a
constructed by A Javan (1926– ) of Bell Telephone scaled-down version of the whole. He was able to
Laboratories in 1961. model the noise distribution as a Cantor dust,
Since then, lasers have found use in a variety of which has the property of containing infinitely
applications, including spectroscopy, repair of reti- many spikes, while being infinitely sparse.
nal detachment in the eye, compact disc (CD) play- His studies of the scalability of such time series
ers and check-out scanners. Maiman left Hughes to led to a famous paper ‘How long is the coast of
found Korad Corporation in 1962 which became a Britain?’, in which he showed that the answer
leading developer and manufacturer of lasers; he depended upon the scale at which you measured it.
also founded Maiman Associates in 1968 and Laser The finer the scale, the greater amount of detail is
Video Corporation in 1972. In 1977 he joined TRW resolved and the longer the coastline appears. Even
Electronics of California. stranger, as the scale of measurement becomes
Malpighi, Marcello [malpeegee] (1628–94) Italian smaller the answer does not tend to a fixed value, as
biologist; discovered capillary blood vessels. one might expect, but to infinity.
Born in the year in which Harvey published his De Mandelbrot went on to show that it is an inherent
motu cordis (1628, On the Motions of the Heart) property of nature to contain roughness at all
describing the circulation of blood in mammals, scales, and to describe this mathematically he
Malpighi graduated at Bologna in philosophy, and devised a geometry with fractional dimensions,
then in medicine in 1653. From 1666 he was profes- rather than the usual integral 1,2,3,4… A well-
sor of medicine there, and the Royal Society of known example is the Koch snowflake, a curve of
London began to publish his work, largely based on infinite length and a fractional dimension of 1.2618.
his microscopy and carried out in the 1660s and Mandelbrot coined the term fractal to describe such
1670s. In 1660 he began his studies of lung tissue, objects, which require fractional dimensions to
and the next year used frog lung. This was well properly describe them; snowflakes and fern leaves
suited to the early microscope, which had devel- are familiar examples of fractals from nature.
oped in Galileo’s time after 1600 but was optically Initially a mathematical curiosity, fractals and
poor; much of the best work in the 1650s was done fractal geometry have increasingly provided
using a single lens rather than a compound system. insights into natural phenomona such as the dis-
Frog lung is almost transparent, with a simple and tribution of earthquakes, and have found applica-
conspicuous capillary system. Malpighi was able to tion in many areas of human activity such as
observe the latter for the first time and to see that it polymers, nuclear reactor safety and economics.
Manson, Sir Patrick (1844–1922) British physician:
was linked to the venous system on one side and to
the arterial system on the other, thereby vindicating pioneer of tropical medicine.
and completing Harvey’s work on the animal circu- Manson qualified in medicine at Aberdeen in
lation. Later he studied the skin, nerves, brain, liver, 1865 and then worked in China for 23 years. He vir-
kidney and spleen, identifying new structures. In tually founded the specialty of tropical medicine,
1669 he gave the first full account of an insect (the in part by his studies of tropical parasitic infection.
silkworm moth) and then began his work on the He studied the life-cycle of the parasite causing
chick embryo. In the 1670s he turned to plant filariasis and deduced that it is passed to man by a
anatomy, discovering stomata in leaves and describ- common brown (Culex) mosquito. These experi-
ing the development of the plant embryo. ments gave the first proof of the necessary involve-
Manton, Sidnie Milana

ment of an insect vector in the life cycle of a para- vertebrate palaeontology by his surgeon’s knowl-
site, but his report on this to the Linnean Society in edge of anatomy. A full-scale model Iguanodon was
1878 was received with ridicule. shown at the Crystal Palace in 1854. Public interest
In London from 1890, he met R Ross and dis- in the massive Mesozoic creatures (up to 35 m long)
cussed the role of mosquitos in malaria. As a result, has remained high ever since.
Manton, Irene (1904–88) British botanist: set up the
Ross went to India and the two collaborated in
studying the life-cycle of malaria parasites in the first laboratory for the ultrastructural study of
mosquito; Manson modestly gave Ross the main plants.
credit for their results. Meanwhile, G B Grassi Irene Manton was the younger sister of Sidnie
(1854–1925), working independently in Rome, Manton; both became Fellows of the Royal Society,
showed in 1898 that human malaria is transmitted the first case of sisters gaining this distinction. She
by mosquito bites and in 1901 he described the was an undergraduate and a postgraduate at
complete, complex life cycle of the parasites caus- Cambridge, and after a short time in Stockholm she
ing the disease. Grassi was able to show that mos- gained a lectureship at the University of Manchester
quitos of the genus Anopheles are exclusively in the early 1930s. Her research at this period was on
responsible, but Ross claimed priority in the overall the spiralization of chromosomes in Lilium and
work on human malaria and in 1902 a Nobel Prize Tradescantia, and on the cytotaxonomy of ferns.
was, somewhat unjustly, awarded solely to him. In 1946 she was appointed to the chair of botany
Manson also studied other parasitic diseases and in Leeds and, while maintaining an interest in her
effectively founded the London School of Tropical previous internationally known work, her research
Medicine in 1899. changed direction. Realizing the possibilities of the
Mantell, Gideon Algernon (1790–1852) British electron microscope, she visited the Rockefeller
geologist: discovered first fossil dinosaurs. Institute in New York and, on her return to England,
Son of a shoemaker in Lewes, Mantell studied borrowed time on electron microscopes in medical
medicine in London. In 1811 he began work as a sur- schools and published remarkable results. She set
geon in Lewes, but his interest in geology increased up a laboratory for the ultrastructural study of
and, after moving to Brighton in 1833, the interest plants and maintained a place at the front of this
became obsessive: his fossil-filled house became a research. She and her colleagues discovered ultra-
public museum and his wife and children were dis- structural classics such as the ‘9 plus 2’ structure of
placed. He wrote much on the small fossils of the cilia, thylakoid organization of choroplasts and
Downs, but his major discovery is that of the first scale formation in Golgi bodies. She had begun her
dinosaur; aquatic saurian remains had been pioneering work with the use of the electron micro-
described previously, but great land saurians scope in the study of algal flagella, with observa-
(dinosaurs) were unsuspected until Mantell’s dis- tions on the spermatozoids of brown algae. She had
coveries in 1822 at Tilgate Forest in the Cretaceous a fruitful collaboration with Mary Winifred Parke
rocks of the English Weald. Mary Anne Mantell, his (1908–89), resulting in 14 papers adding to knowl-
wife, first noticed the teeth, with some bones, and edge of the smaller marine flagellates and revealing
Mantell named the large herbivorous reptile many novel features of fine structure.
Iguanodon, because of its relation to the much In 1961 she was elected a Fellow of the Royal
smaller modern lizard, iguana. In 1832 Mantell dis- Society and was president of the Linnean Society of
covered the armoured dinosaurs. He was essen- London from 1973–6.
Manton, Sidnie Milana (1902–79) British zoolo-
tially an enthusiastic and expert amateur, aided in
gist; a classical zoologist of the first rank.
Sidnie Manton was the elder of two daughters of
a dental surgeon and his Scottish–French wife;
both daughters became Fellows of the Royal
Society, the first case in its history of two sisters
achieving this distinction. At both her London
schools there was an emphasis on biology and she
was encouraged by her parents to collect, study and
draw butterflies, moths and fungi. In 1921 she went
to Girton College, Cambridge, where she took the
Natural Science Tripos and in Part 2 came top of the
final list, but was not awarded the University Prize
as women were not then accepted as full members
of the university. She was appointed as the first
female university demonstrator in comparative
anatomy in Cambridge (1927–35) and in the follow-
ing year obtained her PhD. In 1934 she became the
first woman to be awarded a Cambridge ScD, and
from 1935–42 was director of studies at Girton
College. She married J P Harding in 1937; he
became keeper of zoology at the British Museum
Mary Mantell
Marcet, Jane

and she moved to King’s College, London, becom- advancing rapidly during the early 19th-c. It was
ing Reader in 1949. presented in the form of a discussion between the
Her research was on the structure, physiology and teacher, Mrs Bryan, and two attentive pupils, the
evolution of the arthropods, covering also the func- more serious Emily, and Caroline, who enjoyed
tional morphology and feeding mechanisms of the spectacular experiments. The work was an immedi-
Crustacea, arthropod embryology, the evolution of ate success, and went into 16 editions, each cor-
arthropodian locomotor mechanisms, the mandibu- rected and updated with the latest discoveries and
lar mechanisms of arthropods and arthropod evolu- their applications. The book was also widely sold in
tion. She was the author of The Arthropoda: Habits, the USA. A copy of Conversations on Chemistry was left
Functional Morphology and Evolution (1977). Her influ- at the bookbinder where Faraday was an appren-
ence on zoology was profound and long-lasting. tice, and he credited Jane Marcet’s book with the
She was elected a Fellow of the Royal Society in start of his interest in chemistry.
Marconi, Guglielmo, marquese (Marquis) (1874–
1948, being among the first women to be so hon-
oured. The Linnean Society awarded her its Gold 1937) Italian physicist and engineer: pioneer of
Medal in 1963 and the Zoological Society the Frink radio telegraphy.
Medal in 1977. Of mixed Italian and Irish parentage, Marconi
Marcet, Jane, née Haldimand [mah(r)set] (1769– was privately educated and later studied at the
1858) British writer of introductory science books, Technical Institute of Livorno.
widely read. At the age of 21, intrigued by Hertz’s ‘electric
Jane Haldimand was born in London to Swiss par- waves’, Marconi developed improved radio equip-
ents, and married the Swiss physician Alexander ment capable of transmitting for a range of over a
Marcet (1770–1822), whose interest was in chem- mile (the length of the family estate). To achieve
istry. They made their friends among the London this he used ground connections for both transmit-
scientific circle; Berzelius was a frequent visitor to ter and receiver; larger, elevated antenna; and
their home. Jane Marcet inherited a large fortune Lodge’s coherer as detector, all improvements on
from her father, which enabled her husband to give Hertz’s methods. In 1896 he succeeded in interest-
up his post at Guy’s Hospital and devote his time to ing the British government in his invention, and 3
experimental chemistry; he was elected a Fellow of years later transmitted Morse code across the
the Royal Society. She attended the public lectures English Channel. This attracted considerable atten-
at the Royal Institution given by Humphry Davy, tion, particularly from the Admiralty, who began to
but found she needed further explanation and install his equipment on Royal Navy ships. In 1901
gained this in conversations with ‘a friend’. Her he transmitted across the Atlantic from Cornwall
most successful book was Conversations on Chemistry, to a kite-borne antenna in Newfoundland and
published anonymously in 1805 to assist others to became a household name overnight at the age of
understand scientific discussions; chemistry was 27. In 1909 he shared the Nobel Prize for physics.

Guglielmo Marconi soon after his arrival in England in 1896.
Martin, Archer

Although Marconi did not discover radio waves, dicted from its present state as accurately as if its
and may be thought of as primarily an electrical entire earlier history was known. Markov appears
engineer and businessman, he developed much of to have thought that literary texts were the only
the technology necessary for its practical use, such firm examples of such chains, and applied the idea
as the directional aerial and the magnetic detector. to an analysis of vowels and consonants in a text by
During the First World War he developed short- Pushkin, but his method has since been applied in
wave radio equipment capable of directional trans- quantum theory, particle physics and genetics.
Mariotte, Edmé (?1620–84) French experimental
mission over long distances, and by 1927 had
established a worldwide radio telegraph network physicist.
on behalf of the British government. He spent most Mariotte lived in the same period as Boyle, and in
of his life improving and extending radio as a prac- 1676 he announced his discovery of the same law
tical means of communication and building a com- for gases that Boyle had discovered in 1662. (In
pany to commercialize it; from 1921 he used his France Boyle’s Law is named after Mariotte).
steam yacht Elettra as his home, laboratory and Mariotte noted also the effect of a rise in tempera-
mobile receiving station. ture in expanding a gas; and he attempted to calcu-
Marey, Étienne-Jules [maray] (1830–1904) French late the height of the atmosphere. He also studied
physiologist: ingenious inventor of physiological elastic collisions, colour and the eye (he discovered
instruments. the ‘blind spot’ in 1668). He was a founder member
Marey’s work as a physiologist gave him scope for of the French Académie des Sciences.
Marsh, Othniel Charles (1831–99) US palaeontolo-
his passion for novel mechanical devices. The arter-
ial system of the animal body is a complex arrange- gist.
ment of muscular and elastic tubes; in 1860 Marey A student at Yale, followed by 3 years’ study in
devised a portable sphygmograph, which amplified Europe, Marsh became in 1882 the first vertebrate
the pulse movement and drew a trace of the pulse palaeontologist of the US Geological Survey, as well
wave on smoked paper, and so gave some basic phys- as teaching at Yale. He established his subject in the
iological information. He also began in 1876 to study USA, and his four major expeditions to the western
irregularities of heart action, using his polygraph, USA with his students (and William ‘Buffalo Bill’
which recorded the venous pulse and heartbeat Cody as scout) in the 1870s produced startling fossil
simultaneously; these had not been much noticed discoveries. They included fossil mammals which
previously and he found one type in which at varying showed the evolution of the horse, early primates,
intervals there are two heartbeats that follow abnor- dinosaurs, winged reptiles and toothed birds, and
mally rapidly (extrasystoles). In the 1890s Mackenzie Marsh traced the enlargement of the vertebrate
improved the polygraph, studied heart irregularities brain from the Palaeozoic era.
Martin, Archer (John Porter) (1910–2002) British
further and both related them to disease and showed
that some are non-pathological. biochemist: co-discoverer of paper chromatography.
In 1868 Marey showed that insect wings follow a Martin graduated in Cambridge in 1932 and took
basic figure-of-eight movement, by observing a frag- his PhD there in biochemistry in 1938, working on
ment of gold leaf fixed to the wing tip of a fly held vitamins (this included looking after 30 pigs,
under a spotlight, and also by having the wingtip unaided, in work on pellagra). Then he joined the
brush against the smoked surface of a rotating staff of the Wool Industries Research Association at
cylinder. He saw the value of scientific photography Leeds. There, working with R L M Synge (1914–94)
and in 1881 devised the first useful cine camera, on the problem of separating complex mixtures of
which used a ribbon of sensitized paper with amino acids into their components, he developed
‘stopped motion’ synchronized with a rotating the technique of partition chromatography. By
shutter that cut off light as the paper moved for- 1944 the most familiar form had been devised by
ward. By 1890 he was using this to analyse human Martin; it combined with brilliant simplicity both
and animal movements by high-speed photography the partition and adsorption methods. This is paper
to slow down rapid movements; and he also chromatography, in which a small amount of
invented its converse, time-lapse photography to sample applied as a spot to a piece of paper is
speed up slow changes such as plant growth. From caused to move and to separate into its components
1868 he was professor of natural history at the by allowing a solvent front to move across the
Collège de France, succeeding Flourens. paper. The method is simple and has been of great
Markov, Andrei Andrevich (1856–1922) Russian value to chemists in analysing a variety of complex
mathematician: originator of Markov chains. non-volatile mixtures; it is especially useful in
A graduate of St Petersburg, Markov taught there biochemistry.
for 25 years until his political activism led him in From 1948 Martin was on the staff of the Medical
1917 to a self-imposed exile in the small town of Research Council and from 1953 he worked partic-
Zaraisk. His early work was on number theory and ularly on gas-liquid chromatography. This sepa-
on probability theory, which he worked on from rates volatile mixtures by means of a column of
the 1890s. This led him to discover the sequence of absorbent (such as silicone oil) on an inert support.
random variables now known as Markov chains. A Again, the method has proved a hugely successful
Markov chain is a chance process which has the analytical technique. Martin and Synge shared the
unusual feature that its future path can be pre- 1952 Nobel Prize.
Matthews, Drummond Hoyle

while studying the remanent magnetization of
basalts, Matuyama discovered that the direction of
the Earth’s magnetic field appeared to have
changed its polarity since early Pleistocene times.
Further investigations, notably by A Cox (1926– )
and R Doell in the 1960s, have revealed that the
Earth’s field has abruptly reversed over 20 times
during the past 5 million years, in an apparently
random fashion. Reversals are now believed to be in
some way caused by fluctuations in the convection
currents within the Earth’s liquid core that is the
source of the field. The predominantly reversed
period between 0.7 and 2.4 million years ago is
known as the Matuyama reversed epoch.
Maunder, Edward Walter (1851–1928) British
astronomer: discovered long-term variations in
solar activity.
Maunder, who had no university training, was
appointed photographic and spectrographic assis-
tant at the Greenwich Observatory. In 1893, while
checking historical records of sunspot activity, he
'Drum' Matthews: an informal snapshot made in the realized that between 1645 and 1715 there had
1960s. been little activity, and that in 32 years not a single
sunspot had been seen. This event, which coincided
Matthews, Drummond Hoyle (1931–97) British with a pronounced period of cooling in the Earth’s
geophysicist: his work with F J Vine on magnetic climate (the Little Ice Age), is now known as the
anomalies across mid-ocean ridges aided accep- Maunder minimum. He also discovered that the
tance of plate tectonic theory. solar latitude at which sunspots appear varies in a
Matthews served in the Royal Navy before study- systematic way during the solar cycle.
ing science at Cambridge. Survey work in the South Maunder married Annie Scott Dill Russell
Atlantic Ocean preceded return to Cambridge and (1868–1947), a ‘lady computor’ at Greenwich
further work in marine geophysics, in the Atlantic Observatory appointed in 1891. She had been a stu-
and Indian Oceans. dent at Girton College, Cambridge and had won
Together with his student Vine, Matthews high honours, Senior Optime in the Mathematical
showed in 1963 that the oceanic crust on either side Tripos. They worked in close collaboration and pub-
of mid-ocean ridges is remanently magnetized in lished prolifically on the Sun, and on popular
alternately normal and reversed polarity, in bands astronomy.
Maury, Antonia (Caetana de Paiva Pereira)
running parallel to the ridge. This, they argued, was
consistent with the sea-floor spreading hypothesis [mawree] (1866–1952) US astronomer; made impor-
proposed by H H Hess the year before, and was seen tant contributions to sidereal astronomy.
as powerful support for Hess’s hypothesis. Newly- Antonia Maury was the niece of Henry Draper
formed crust would become magnetized in the pre- (1837–82) who first photographed stellar spectra,
vailing direction of the Earth’s magnetic field at the and a grand-daughter of J W Draper, a pioneer in
time of its emergence, but since this field under- the application of photography to astronomy. Her
goes periodic reversals, the oceanic crust would be great-grandfather had been British physician to
expected to be magnetized alternately in opposite Pedro I, emperor of Brazil; his wife was Portuguese.
directions. Vine and Matthews showed that this Maury graduated from Vassar College in 1887
was indeed the case, and also showed that the mag- and, at the request of her father, was employed by
netic patterns were symmetrical about the mid- Edward Pickering (1846–1919) at Harvard College
ocean ridges and that the same patterns were Observatory classifying the bright northern stars
found for ridges in different oceans. according to their spectra. Pickering had just estab-
In 1980, with D Blundell, the very popular ‘Drum’ lished Mizar as the first spectroscopic binary (ie a
Matthews founded the British Institutions binary detected by the Doppler shift in spectral
Reflection Profiling Syndicate (BIRPS), which col- lines, due to the relative motion of the pair of stars);
lated data from deep seismic reflections to study Maury determined its period as 104 days. In 1889
the lithosphere to depths of 80 km, an order of mag- she discovered the second spectroscopic binary
star, β Aurigae, with a period of about 4 days. In
nitude deeper than could be reached by drilling.
Matuyama, Motonori (1884–1958) Japanese geolo- 1890 Williamina Fleming’s (1857–1911) Draper
gist: discovered reversals in Earth’s magnetic field. Catalogue of Stellar Spectra was published. Maury had
The son of a Zen abbot, Matuyama taught at the been assigned a more detailed study of the brighter
Imperial University in Kyoto and studied at the stars, made possible by placing three or four prisms
University of Chicago before being appointed pro- in front of the 11 in (28 cm) Draper refractor (nearly
fessor of theoretical geology at Kyoto. In 1929, the last scientific use to which the famous telescope
Maxwell, James Clerk

was put before it was sent to China). Maury discov-
ered deficiencies in the Draper Catalogue system
and devised her own, published in 1896, in which
she classified the spectra by the width and distinct-
ness of their lines: spectra with (a) normal lines, (b)
hazy lines and (c) sharp lines, with subdivisions.
Hertzsprung used this to verify his discovery of
dwarfs (a and b) and giants (c), and considered
Maury’s system a major advance. Pickering refused
to acknowledge its value and it was largely ignored
at Harvard in favour of the system used by Annie
Jump Cannon. The merits of Maury’s system were
eventually recognized in 1943 when she received
the Annie Jump Cannon Prize from the American
Astronomical Society. Her work is now considered
an essential step in the development of theoretical
The conflict between Pickering and Maury
impeded her career. Her aunt, Henry Draper’s widow
and benefactor of the Harvard Observatory, urged
Pickering to ‘bid her goodbye without regret’. Maury
left the Observatory in 1891 for a teaching position,
returning to resume her work, under Pickering’s
successor Shapley, on spectroscopic binaries.
Maury, Matthew Fontaine [mawree] (1806–73) US
James Clerk Maxwell aged 24, holding the top used in
oceanographer: conducted first systematic survey colour vision demonstrations.
of ocean winds and currents.
Sometimes referred to as ‘the father of physical
oceanography’, Maury was a US naval officer who home-designed clothes and sense of humour
was forced to retire due to a leg injury. In 1842 he gained him the undeserved nickname of ‘Dafty’,
became director of the US Naval Observatory and and possibly caused his shyness; he was happier at
Hydrographic Office, and organized the first sys- Edinburgh University, which he entered at 16. The
tematic collection of information on winds and previous year he had developed the known method
currents from merchant ships, greatly improving of drawing an ellipse using pins and thread, to gen-
knowledge about oceanic and atmospheric circula- erate a series of novel curves. The work was pub-
tion. In 1847 he began to publish pilot charts, lished by the Royal Society of Edinburgh in 1846.
which enabled sailing voyages to be dramatically In 1850 he entered Trinity College, Cambridge
shortened, cutting as much as a month from the and graduated as Second Wrangler, winning the
New York to California voyage. Maury also pro- Smith’s Prize (1854). Then 2 years later he secured a
duced the first bathymetric profile across the professorship at Marischal College, Aberdeen,
Atlantic (from Yucatan to Cape Verde), with a view where he married the principal’s daughter, but an
to the laying of a submarine cable. By 1850 he knew administrative reorganization made him redun-
that a sea floor ridge ran down the northern length dant and in 1860 he moved to King’s College,
of the Atlantic Ocean, but the significance of this London. After the death of his father (1865), who
and its relation to tectonic plate theory did not had cared for him since his mother died when he
emerge for over a century. By the 1960s Ewing and was 8 and of whom he was very fond, he resigned
Heezen and Marie Tharp, by combining all avail- his post at King’s and remained at the family home
able bathymetric soundings of the Atlantic, had in Scotland as a gentleman-farmer doing research.
also revealed the rift valley and saw its bearing on However, he was persuaded to become the first
tectonic plate theory. The ridges were explored in Cavendish Professor of Experimental Physics in
1974 by R D Ballard (1942– ) of the US Navy Cambridge, setting up the laboratory in 1874. He
Reserve using manned submersibles; he also exam- contracted cancer 5 years later and died soon after-
ined hot vents and their fauna. He discovered the wards, aged 48. In setting up the Cavendish
Titanic in 1985. Laboratory, he formed an institution unique in
At the outbreak of the American Civil War in 1861 physics, to be headed by a succession of men of
he became commander of the Confederate Navy, a genius and producing graduates who dominated
move which later led to a period of exile in Mexico the subject for generations.
and England. Maxwell was the most able theoretician of the
Maxwell, James Clerk (1831–79) British physicist: 19th-c, perfectly complementing Faraday, who was
produced the unified theory of electromagnetism its most outstanding experimentalist. He began
and the kinetic theory of gases. research on colour vision in 1849, showing how all
Maxwell went to school at the Edinburgh Aca- colours could be derived from the primary colours
demy, a harsh institution where his country accent, red, green and blue. This led, in 1861, to his pro-
May, Sir Robert

ducing the first colour photograph using a three- depends on temperature, and that heat is stored in
colour process; the photograph was of a tartan. a gas in the motion of the gas molecules. The theory
Other early work (1855–9) showed that Saturn’s was then used to explain the viscosity, diffusion
rings must consist of many small bodies in orbit and thermal conductivity of gases.
rather than a solid or fluid ring, which he showed Maxwell and his wife found experimentally
would be unstable. He casually referred to this as (1865) that gas viscosity is independent of pressure
‘the flight of the brickbats’. and that it is roughly proportional to the tempera-
His monumental research on electromagnetism ture, and rises with it (the reverse of the behaviour
had small beginnings. Faraday viewed electric and of liquids). This did not agree with Maxwell’s
magnetic effects as stemming from fields of lines of theory, and he could only gain agreement by
force about conductors or magnets, and Maxwell assuming that molecules do not collide elastically
showed that the flow of an incompressible fluid but repel one another with a force proportional to
would behave in the same way as the fields (1856). their separation raised to the fifth power. This and
Then, in 1861–2, he developed a model of electro- further work by Boltzmann from 1868 allowed the
magnetic phenomena using the field concept and full development of the kinetic theory of gases.
analogous vortices in the fluid which represented Maxwell was a shy and mildly eccentric person,
magnetic intensity, with cells representing electric who was deeply religious, with a strong sense of
current. Having explained all known electro- humour and no trace of pomposity. Like Einstein,
magnetic phenomena, Maxwell introduced elasti- and in contrast to Newton or Faraday, Maxwell
city into the model and showed that transverse made his enormous advances in physics without
waves would be propagated in terms of known fun- excessive mental strain. He excelled in his sure
damental electromagnetic constants. He calcu- intuition in physics, in applying visual models or
lated that the waves would move at a speed very mathematical methods without being tied to them,
close to the measured speed of light. He unhesitat- and above all in freeing himself from preconcep-
ingly inferred that light consists of transverse elec- tions and in exercising his creative imagination.
tromagnetic waves in a hypothetical medium (the Maxwell’s summary of electromagnetism in his
‘ether’). field equations is an achievement equalled only by
To study electromagnetic waves further, the fluid that of Newton and Einstein in mechanics.
May, Sir Robert (1936– ) Australian theoretical
analogy was taken over into a purely mathematical
description of electromagnetic fields. In 1864 he physicist, zoologist and ecologist.
developed the fundamental equations of electro- May was educated at Sydney Boys’ High School,
magnetism (Maxwell’s equations) and could then where he was taught chemistry by a man whose
show how electromagnetic waves possess two cou- products include six FRSs and a Nobel Laureate. He
pled disturbances, in the electric and magnetic encouraged May to study chemical engineering at
fields, oscillating at right angles to one another and Sydney, but May’s interest moved towards physics
to the direction in which the light is moving. The and maths and his doctorate was in theoretical
original mechanical model was now rightly cast physics. He later held a chair in that field at Sydney
off. from 1969. Soon however he applied this expertise
Furthermore, Maxwell stated that light repre- to ecological problems: he devised mathematical
sented only a small range of the spectrum of elec- models for calculating how many similar species
tromagnetic waves available. Hertz confirmed this can share a habitat but retain their individuality;
in 1888 by discovering another part of the spec- and he worked on the conditions leading to stabil-
trum, radio waves, but by this time Maxwell was ity, or to chaos, in ecosystems generally.
dead. Maxwell also suggested the Michelson– At Princeton as professor of biology from 1973–88
Morley experiment (1881, 1887) to search for an he extended these interests to modelling the popu-
absolute electromagnetic medium (the ether). Its lation biology of infectious diseases in both marine
proven absence prompted Einstein’s research on and human communities. From 1995 he served as a
relativity (1905) and the era of modern physics. well-regarded Chief Scientific Adviser to the UK
Maxwell also contributed to the kinetic theory of government while also holding chairs in zoology at
gases, building on the existing picture of a gas as Oxford and at Imperial College, in the period when
consisting of molecules in constant motion, collid- BSE and GM food both provided difficult problems,
ing with their container and with each other; this lacking traditional well-defined solutions.
Mayow, John (1641–79) English physician: early
picture was due to Bernoulli and to two little-
known men, J Herapath (1790–1868) and J J experimenter on combustion.
Waterston (1811–83). As gases diffuse into each Mayow studied law and medicine at Oxford, prac-
other rather slowly, Clausius deduced that tised medicine in Bath, and experimented in
although they travel fast, the molecules must have Oxford where he perhaps worked with Hooke and
a very small ‘mean free path’ between collisions. Boyle. In a book published in 1674 he gives a theory
From 1860 Maxwell (and independently Boltz- of combustion similar to Hooke’s but supported by
mann) used statistical methods to allow for the new experiments. He burned candles in air in a
wide variation in the velocities of the various mole- closed space over water, and found that the
cules in the gas, deriving the Maxwell–Boltzmann reduced volume of gas which remained would not
distribution of velocities. Maxwell showed how this support combustion; he got similar results using a
Meitner, Lise

mouse in place of a burning candle to consume part human blood a large proportion of the white cells
of the air. He concluded that air consists of a least (leucocytes) are phagocytic and will attack invading
two parts; one (‘the nitro-aerial spirit’) supports bacteria. Infection leads to an increase in the
combustion or respiration, which are in this way number of white cells, and phagocytosis at the site
related processes; the other part of air is inert. of a local infection leads to inflammation and a hot,
Ignited gunpowder continued to burn under water, red, swollen and painful region with dead phago-
so its ‘nitre’ contained the nitro-aerial spirit; it is cytes forming pus. From 1898 Mechnikov studied
surprising he did not try heating nitre (KNO3) alone human ageing; he believed that phagocytes even-
and so discover oxygen, and this may be because he tually began to digest the cells of the host (an early
visualized his ‘spirit’ as a philosophical principle idea of auto-immune disease) aided by the effects of
rather than as a gaseous substance. In experiments intestinal bacteria. If these effects could be resisted,
with an air-pump (probably Boyle’s) he found that he argued, the normal human life-span would be
venous blood under the pump effervesced only 120–130 years. For his work on phagocytosis he
gently, but arterial blood bubbled freely if fresh. He shared a Nobel Prize in 1908.
Medawar, Sir Peter Brian [medawah(r)] (1915–87)
had sensible, if primitive, views on chemical affin-
ity. In many ways Mayow was ingenious both as an British immunologist: pioneer in study of immuno-
experimenter and in ideas, but it can be said also logical tolerance.
that few of the ideas were new and his theory of Born in Brazil, the son of a Lebanese–British busi-
combustion was hopelessly confused in compari- ness man, Medawar was educated in England at
son with Lavoisier’s clear-mindedness a century Marlborough (which he much disliked) and then at
later. Oxford, studying zoology under J Z Young (1907– )
Mead, Margaret (1901–78) US social anthropologist. from 1932. In the 1940s he began to study skin
The eldest daughter in an academic family, grafts in connection with wartime burns victims,
Margaret Mead was educated mainly at home until and when he moved in 1947 to Birmingham he con-
she entered Barnard College, where Ruth Benedict tinued this interest. He was a keen and skilful
was senior to her and became a close friend. In 1923 experimenter; he was aware that grafts are success-
she married the first of her three anthropologist ful between certain types of twins and he knew of
husbands, with all of whom she collaborated, as the Burnet’s work, suggesting that an animal’s ability
senior partner, in ethnographic studies of Pacific to produce antibodies against foreign cells (and
island cultures. She wrote in all over 40 books, some hence rejection of a transplanted tissue) is not
of which, like Coming of Age in Samoa (1928), became inherited but is developed in fetal life, and so he
best-sellers and helped her become the world’s best- believed that ‘immunological tolerance’ should be
known anthropologist. Her work examined adoles- achievable. Medawar’s ingenious work with mouse
cence, child rearing, gender roles and the rift skin grafts supported Burnet’s idea. From this
between generations, and illuminated these and stemmed the successful human organ transplants
related cultural patterns through comparisons achieved by surgeons from the 1960s, using tissue-
between primitive and developed societies. As a typing to secure a partial matching between the
result, social anthropology became accessible to donor organ and the patient, and also using
non-specialists and aided them in understanding immunosuppressive drugs to inhibit the normal
their own society. immune response that would cause rejection.
In the Second World War she studied food habits Medawar moved to London in 1951, and shared a
and also worked to reduce British–US cultural con- Nobel Prize with Burnet in 1960. He did not allow
flicts and misunderstanding, and afterwards she the strokes he had in his last 18 years to much limit
returned to senior posts in the American Museum his work, and his seven popular books were written
of Natural History and in Columbia University, New in this period.
Meitner, Lise [miytner] (1878–1968) Austrian–
York. Her general beliefs were optimistic; in think-
ing that cultural factors were more important than Swedish physicist and radiochemist: co-discoverer
biological ones in shaping human behaviour, she of nuclear fission.
also believed that this behaviour was essentially Meitner studied physics in Vienna under Boltz-
alterable in favourable circumstances. mann and in Berlin with Planck. Soon she was
Mechnikov, Ilya Ilich (Russ), Elie Metchnikof (Fr) attracted into radiochemistry, and worked with
[mechnikof] (1845–1916) Russian–French biologist: Hahn in Berlin in this field for 30 years.
discoverer of phagocytosis. Despite her talents she was a victim of more than
Educated in Russia and Germany, Mechnikov one prejudice, being both female and a Jewish
taught zoology in Odessa from 1872. Some 10 years Protestant. In academic Vienna she was regarded as
later he inherited modest wealth and went to a freak; she was only the second woman to obtain a
Messina in Italy on a research visit. There he studied doctorate in science there. In Berlin, E Fischer
the conveniently transparent larvae of starfish and could not allow women in the laboratory, although
noticed that some of their cells could engulf and he welcomed her 2 years later when the State regu-
digest foreign particles; he called these amoeba-like lations changed. In 1912 she began working with
cells ‘phagocytes’ (cell-eaters). In 1888 he moved to Hahn at Berlin-Dahlem, but the war soon inter-
Paris to the Pasteur Institute and continued his rupted their work. His leaves from the German
search for phagocytic action. He found that in Army sometimes coincided with hers from nursing
Mendel, Gregor

duty in the Austrian Army; however, some radio- monastery garden. He was elected abbot in 1868,
chemistry involves long gaps between measure- which left him little time to continue this work; in
ments; and so they were able to continue some of any event his personality and reputation were
their work and announce a new radioelement, prot- unsuited to publicize his scientific ideas and most
actinium, at the war’s end. In 1918 she became biological interest was directed elsewhere. Mendel’s
head of physics in the Institute, and continued her work had to await rediscovery by de Vries and
work on radioactivity. others to become appreciated, in 1900. Even then it
In the 1930s she and Hahn worked on uranium needed the vigorous advocacy of Bateson, and
bombarded with neutrons, initially not realizing many plant and animal breeders, to be accepted.
that fission was occurring. By the late 1930s her Mendel’s famous work on the inheritance of char-
Jewishness was a threat to her safety, and friends acters was done on the edible pea (Pisum spp.), in
(including Hahn and Debye) helped her escape which he studied seven characters, such as stem
through Holland to Denmark and then to Sweden. height, seed shape and flower colour. The plants
In Stockholm a cyclotron was being built; although were self-pollinated, individually wrapped (to pre-
aged 60 she learned Swedish and built up her vent pollination by insects) and the seeds collected
research group again. Hahn sent her the results of and their offspring studied. The characters were
his work on neutron bombardment of uranium, shown not to blend on crossing, but to retain their
begun with her and F Strassmann (1902–80), but identity. Mendel had a gardener’s skill and his
which he had erroneously interpreted. She dis- experiments were excellently organized. He found
cussed the work with her nephew Frisch who was that the characters were inherited in a ratio always
visiting her. They shaped their joint and novel ideas close to 3:1; he theorized that hereditary elements
on ‘nuclear fission’ into a paper, which was actually or factors (now called genes) exist that determine
composed over a telephone line since he had by the characters, and that these segregate from each
then returned to Copenhagen. other in the formation of the germ cells (gametes).
She declined to work on the atomic bomb, hoping His results of 1856 are summarized in two laws,
that the project would prove impossible, and did no expressed in modern terms as follows. The charac-
more work on fission. In 1960 she retired to live in ters of a diploid organism are controlled by alleles
England after 22 years in Sweden. occurring in pairs. Of a pair of such alleles, only one
Mendel, Gregor (Johann) (1822–84) Austrian can be carried in a single gamete. This is Mendel’s
botanist: discovered basic statistical laws of heredity. First Law, or the law of segregation. We now know,
In the long term Mendel was certainly successful; although Mendel did not, that this law follows from
he laid a foundation for the science of genetics. In the process of meiosis and the physical existence of
another sense he was a failure; he did not succeed alleles as genes. He also found that each of the two
in examinations and his research was largely alleles (ie the two forms) of one gene can combine
ignored until 16 years after his death. randomly with either of the alleles of another gene
A peasant farmer’s son, he entered the Augus- (Mendel’s Second Law, or the law of independent
tinian monastery in Brno (then in Moravia, now the assortment). Genetics has both confirmed and
Czech Republic) when he was 21 and was ordained 4 refined Mendel’s laws; Morgan’s work showed how
years later. He became a junior teacher and during linkage and crossing-over modify the second law.
the 1850s twice tried to pass the teachers’ qualifying Mendel was disappointed that his work aroused
examination. From 1851 he was sent by his order to little interest and he sent his paper to Naegeli, the
study science for 2 years in Vienna, and afterwards leading German botanist, who advised him to
he began his plant-breeding experiments in the experiment with more plants; Mendel had already
studied 21 000. Curiously, when Fisher in 1936
studied his results, he found they are statistically
too ideal; possibly because a few intermediate
plants occur, which Mendel classified to accord
with his expectations. Or, perhaps, an assistant
tried too hard to be helpful.
Mendelayev, Dmitri Ivanovich [mendelayef]
(1834–1907) Russian chemist: devised periodic
table of chemical elements.
Mendelayev grew up in Siberia, the last-born of a
family of 14 children. His father, a teacher, became
blind at this time, but his mother was a forceful
woman and she reopened and ran a nearby glass
factory to give an income. When Dmitri was 14 his
father died and the factory was destroyed by fire;
but the boy had done well at school and his mother
decided that he deserved more education. They
made the long trip to St Petersburg and he began to
study chemistry, and was so successful (despite
much illness) that he was given an award to study
Gregor Mendel in the 1850s
1 2 3 4 5 6 7 8
1 1 2

H H He Helium
Hydrogen Hydrogen
1.00794 1.00794 4.00260
3 4 5 6 7 8 9 10

Li Be Boron Carbon Nitrogen Oxygen Fluorine Neon
Lithium Ber yllium
6.941 9.01218 10.81 12.01 1 14.0067 15.9994 18.998403 20.179
11 12 13 14 15 16 17 18

Al Si P S Cl Ar
Na Mg Aluminium Silicon Phosphorus Sulphur Chlorine Argon
Sodium Transition series
22.98977 22.98977 26.98154 28.0855 30.97376 32.06 35.453 39.948
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Potassium Calcium Scardium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
39.0983 40.08 44.9559 47.88 50.9415 51.996 54.9380 55.847 58.9332 58.69 63.546 65.38 69.72 72.59 74.9216 78.96 79.904 83.80
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Cadmium Indium Tin Antimony Tellenum Iodine Xenon
85.4678 87.62 88.9059 91.22 92.9064 95.94 (98) 101.07 102.9055 106.42 107.8682 112.41 114.82 118.69 121.75 127.60 126.9045 131.29
55 56 57–71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
Cs Ba Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
(rare earth
Caesium Barium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Thallium Lead Bismuth Polonium Astatine Radon
Mercur y
132.9054 137.33 178.49 180.7479 180.7479 186.207 190.2 192.2 195.08 196.9665 200.59 204.383 207.2 208.9804 (209) (210) (222)
89–103 106 107
105 108 109 110 111 112 114 116 118
87 88
Actinide series
Traces Traces Traces Traces Traces Traces
made in made in made in made in made in made in
rare earth Db Sg Bh Hs Mt


ńňđ. 12
(âńĺăî 21)