Thomas Young (1773-1829) contributed 63 articles to the Encyclopedia Britannica, including 46 biographical entries (mostly on scientists and classicists) and substantial essays on "Bridge," "Chromatics," "Egypt," "Languages" and "Tides". Was someone who could write authorita-tively about so many subjects a polymath, a genius or a dilettante? In an ambitious new biog-raphy, Andrew Robinson argues that Young is a good contender for the epitaph "the last man who knew everything." Young has competition, however: The phrase, which Robinson takes for his title, also serves as the subtitle of two other recent biographies: Leonard Warren's 1998 life of paleontologist Joseph Leidy (1823-1891) and Paula Findlen's 2004 book on Athanasius Kircher (1602-1680), another polymath.

Young, of course, did more than write encyclopedia entries. He presented his first paper to the Royal Society of London at the age of 20 and was elected a Fellow a week after his 21st birthday. In the paper, Young explained the process of accommodation in the human eye —on how the eye focuses properly on objects at varying distances. Young hypothesised that this was achieved by changes in the shape of the lens. Young also theorised that light traveled in waves and ho believed that, to account for the ability to see in color, there must be three receptors in the eye corresponding to the three "principal colors" to which the retina could respond: red, green, violet. All these hypotheses Were subsequently proved to be correct.

Later in his life, when he was in his forties, Young was instrumental in cracking the code that unlocked the unknown script on the Rosetta Stone, a tablet that was "found" in Egypt by the Napoleonic army in 1799. The stone contains text in three alphabets: Greek, something unrecognisable and Egyptian hieroglyphs. The unrecognisable script is now known as demotic and, as Young deduced, is related directly to hieroglyphic. His initial work on this appeared in his Britannica entry on Egypt. In another entry, he coined the term Indo-European to describe the family of languages spoken throughout most of Europe and northern India. These are the landmark achievements of a man who was a child prodigy and who, unlike many remarkable children, did not disappear into oblivion as an adult.

Bom in 1773 in Somerset in England, Young lived from an early age with his maternal grandfather, eventually leaving to attend boarding school. He had devoured books from the age of two, and through his own initiative he excelled at Latin, Greek, mathematics and natural philosophy. After leaving school, he was greatly encouraged by his mother's uncle, Richard Brock-lesby, a physician and Fellow of the Royal Society. Following Brocklesby's lead, Young decided to pursue a career in medicine. He studied in London, following the medical circuit, and then moved on to more formal education in Edinburgh, Gottingen and Cambridge. After completing his medical training at the University of Cambridge in 1808, Young set up practice as a physician in London. He soon became a Fellow of the Royal College of Physicians and a few years later was appointed physician at St. George's Hospital.

Young's skill as a physician, however, did not equal his skill as a scholar of natural philosophy or linguistics. Earlier, in 1801, he had been appointed to a professorship of natural philosophy at the Royal Institution, where he delivered as many as 60 lectures in a year. These were published in two volumes in 1807. In 1804 Young had become secretary to the Royal Society, a post he would hold until his death. His opinions were sought on civic and national matters, such as the introduction of gas lighting to London and methods of ship construction. From 1819 he was superintendent of the Nautical Almanac and secretary to the Board of Longitude. From 1824 to 1829 he was physician to and inspector of calculations for the Palladian Insurance Company. Between 1816 and 1825 he contributed his many and various entries to the Encyclopedia Britan-nica, and throughout his career he authored numerous books, essays and papers.

Young is a perfect subject for a biography — perfect, but daunting. Few men contributed so much to so many technical fields. Robinson's aim is to introduce non-scientists to Young's work and life. He succeeds, providing clear expositions of the technical material (especially that on optics and Egyptian hieroglyphs). Some readers of this book will, like Robinson, find Young's accom-plishments impressive; others will see him as some historians have —as a dilettante. Yet despite the rich material presented in this book, readers will not end up knowing Young personally. We catch glimpses of a playful Young, doodling Greek and Latin phrases in his notes on medical lectures and translating the verses that a young lady had written on the walls of a summerhouse into Greek elegiacs. Young was introduced into elite society, attended the theatre and learned to dance and play the flute. In addition, he was an accomplished horseman. However, his personal life looks pale next to his vibrant career and studies.

Young married Eliza Maxwell in 1804, and according to Robinson, "their marriage was a happy one and she appreciated his work," Almost all we know about her is that she sustained her husband through some rancorous disputes about optics and that she worried about money when his medical career was slow to take off. Very little evidence survives about the complexities of Young's relationships with his mother and father. Robinson does not credit them, or anyone else, with shaping Young's extraordinary mind. Despite the lack of details concerning Young's rela-tionships, however, anyone interested in what it means to be a genius should read this book.

A A little over a century ago, men of the ilk of Scott, Shackleton and Mawson battled against Antarctica’s blizzards, cold and deprivation. In the name of Empire and in an age of heroic deeds they created an image of Antarctica that was to last well into the 20th century—an image of remoteness, hardship, bleakness and isolation that was the province of only the most courageous of men. The image was one of a place removed from everyday reality, of a place with no apparent value to anyone.

B As we enter the 21st century, our perception of Antarctica has changed. Although physically Antarctica is no closer and probably no warmer, and to spend time there still demands a dedication not seen in ordinary life, the continent and its surrounding ocean are increasingly seen to be an integral part of Planet Earth, and a key component in the Earth System. Is this because the world seems a little smaller these days, shrunk by TV and tourism, or is it because Antarctica really does occupy a central spot on Earth’s mantle? Scientific research during the past half century has revealed—and continues to reveal—that Antarctica's great mass and low temperature exert a major influence on climate and ocean circulation, factors which influence the lives of millions of people all over the globe.

C Antarctica was not always cold. The slow break-up of the super-continent Gondwana with the northward movements of Africa, South America, India and Australia eventually created enough space around Antarctica for the development of an Antarctic Circumpolar Current (ACC), that flowed from west to east under the influence of the prevailing westerly winds. Antarctica cooled, its vegetation perished, glaciation began and the continent took on its present-day appearance. Today the ice that overlies the bedrock is up to 4km thick, and surface temperatures as low as -89.2deg C have been recorded. The icy blast that howls over the ice cap and out to sea—the so-called katabatic wind—can reach 300 km/hr, creating fearsome wind-chill effects,

D Out of this extreme environment come some powerful forces that reverberate around the world. The Earth’s rotation, coupled to the generation of cells of low pressure off the Antarctic coast, would allow Astronauts a view of Antarctica that is as beautiful as it is awesome. Spinning away to the northeast, the cells grow and deepen, whipping up the Southern Ocean into the mountainous seas so respected by mariners. Recent work is showing that the temperature of the ocean may be a better predictor of rainfall in Australia than is the pressure difference between Darwin and Tahiti—the Southern Oscillation Index. By receiving more accurate predictions, graziers in northern Queensland are able to avoid overstocking in years when rainfall will be poor. Not only does this limit their losses but it prevents serious pasture degradation that may take decades to repair. CSIRO is developing this as a prototype forecasting system, but we can confidently predict that as we know more about the Antarctic and Southern Ocean we will be able to enhance and extend our predictive ability.

E The ocean’s surface temperature results from the interplay between deep-water temperature, air temperature and ice. Each winter between 4 and 19 million square km of sea ice form, locking up huge quantities of heat close to the continent. Only now can we start to unravel the influ-ence of sea ice on the weather that is experienced in southern Australia. But in another way the extent of sea ice extends its influence far beyond Antarctica. Antarctic krill—the small shrimp-like crustaceans that are the staple diet for baleen whales, penguins, some seals, flighted sea birds and many fish—breed well in years when sea ice is extensive and poorly when it is not. Many species of baleen whales and flighted sea birds migrate between the hemispheres and when the krill are less abundant they do not thrive.

F The circulatory system of the world’s oceans is like a huge conveyor belt, moving water and dis-solved minerals and nutrients from one hemisphere to the other, and from the ocean's abyssal depths to the surface. The ACC is the longest current in the world, and has the largest flow. Through it, the deep flows of the Atlantic, Indian and Pacific Oceans are joined to form part of a single global thermohaline circulation, During winter, the howling katabatics sometimes scour the ice off patches of the sea's surface leaving large ice-locked lagoons, or ’polynyas'. Recent research has shown that as fresh sea ice forms, it is continuously stripped away by the wind and may be blown up to 90km in a single day. Since only fresh water freezes into ice, the water that remains becomes increasingly salty and dense, sinking until it spills over the continental shelf. Cold water carries more oxygen than warm water, so when it rises, well into the northern hemi-sphere, it reoxygenates and revitalises the ocean. The state of the northern oceans, and their biological productivity, owe much to what happens in the Antarctic.

A What counts as knowledge? What do we mean when we say that we know some-thing? What is the status of different. kinds of knowledge? In order to explore those questions we are going to focus on one particular area of knowledge medicine.

B How do you know when you are ill? This may seem to be an absurd question. You know you are ill because you feel ill; your body tells you that you are ill. You may know that you feel pain or discomfort Iml knowing you are ill is a bit. more complex. At times, people experience the symptoms of illness, but in tact they are simply tired or over-worked or they may just have a hangover. At other limes, people may be suffering from a disease and fail to be aware of the illness until it has reached a late stage in its development. So how do we know we are ill, and what counts as knowledge?

C Think about this example. You feel unwell. You have a bad cough and always seem to be tired. Perhaps it could be stress at work, or maybe you should give up smoking. You tool worse. You visit the doctor who listens to your chest and heart, take's your temperature and blood pressure, and then finally prescribes antibiotics lor your cough.

D Things do not improve but you struggle on thinking you should pull yourself together, perhaps things will ease off at work soon. A return visit to your doctor shocks you. This time the doctor, drawing on yours of training and experience, diagnoses pneumonia. This means that you will need bed rest and a consider able time off work. The scenario is transformed. Although you still have the same symptoms, you no longer think that these are caused by pressure at work. You now have proof that you are ill. This is the result of the combination of your own subjective experience and the diagnosis of someone who has the stains of a medical expert. You have a medically authenticated diagnosis and it appears that you are seriously ill; you know you are ill and have evidence upon which to base this knowledge.

E This scenario shows many different sources of knowledge. For example, you decide to consult the doctor in the first place because you feel unwell - this is personal knowledge about your own body. However, the doctor's expert diagno-sis is based on experience and training, with sources of knowledge as diverse as other experts, laboratory reports, medical textbooks and yours of experience.

F One source of knowledge is the experience of our own bodies; the personal knowledge we have of change's that might be significant, as well as the subjec-tive experience of poin and physical distress. These experiences are mediated by other forms of knowledge such as the words we have available to describe our experience and the common sense of our families and friends as well as that drown from popular culture. Over the post decade, for example, Western culture has seen a significant emphasis on stress-related illness in the media. Refer-ence to being ‘stressed end' has become a common response in daily exchanges in the workplace and has become port of popular common-sense knowledge. It is thus not surprising that we might seek such an explanation of physical symp-toms of discomfort.

G We might also rely on Ihe observations of others who know us. Comments from friends and family such as ‘you do look ill' or 'that's a bad cough' might be another source of knowledge. Complementary health practices, such as holistic medicine, produce their own sets of knowledge upon which we might also draw in deciding the nature and degree of our ill health and about possible treatments.

H Perhaps the most influential and authoritative source of knowledge is the medical knowledge provided by the general practitioner. We expect he doctor to hove access to expert knowledge. This is socially sanctioned. It would not be acceptable to notify our employer Unit we simply felt too unwell to turn up for work or that our faith healer, astrologer, therapist or even our priest thought it was not a good idea. We need on expert medical diagnosis in order to obtain the necessary certificate it we need to be off work for more than the statutory self-certificaion period. The knowledge of the medical sciences is privileged in this respect in contemporary Western culture. Medical practitioners are also seen as having the required expert knowledge that permits then legally to pre-scribe drugs and treatment to which patients would not. otherwise have access. However there is a rauge of different knowledge upon which we draw when making decisions about our own state of health.

I However, there is more than existing knowledge in this little story; new knowledge is constructed within it.Given the doctor's medical training and background, she may hypothrsie 'is this now pneumonia?' and then proceed to look for eevidence about it. She will use observations and instruments to assess the evidence and-critically-interpret it in the light of her training and new experience both for you and for the doctor. This will then be added to the doctor's medical knowledge and may help in future diagnosis of pneumonia.