In Our Time: Science

Melvyn Bragg and guests discuss the history of microbiology. We have more microbes in our bodies than we have human cells. We fear them as the cause of disease, yet are reliant on them for processes as diverse as water purification, pharmaceuticals, bread-making and brewing. In the future, we may look to them to save the planet from environmental hazards as scientists exploit their ability to clean up pollution. For microbes are the great recyclers on the earth, processing everything – plants, animals and us. Without microbes life would grind to a halt. How did we first discover these invisible masters of the universe? The development of microscopes in the 17th Century played a key part, but for a while science seemed stuck in this purely observational role. It is only when Louis Pasteur and Robert Koch began to manipulate microbes in the lab two hundred years later that stunning advances were made. These breakthroughs led to an understanding of how microbes transform matter, spread disease and also prevent i

Melvyn Bragg and guests discuss the history of optics. From telescopes to microscopes, from star-gazing to the intimacies of a magnified flea. As Galileo turned his telescope to the heavens in the early 1600s, Kepler began to formulate a theory of optics. The new and improving instruments went hand in hand with radical new ideas about how we see and what we see. Spectacles allowed scholars to study long into the evening (and into old age), while giant telescopes, up to 100 feet long, led to the discovery of planets and attempts to map the universe. The craze for optical trickery swept Europe with enthusiastic amateurs often providing valuable discoveries. But this new view of the world through a lens raised questions too – how much can you rely on the senses, on what you see? The further into space you can spy, the larger and more unmanageable the universe becomes. At the same time, the microscope was utterly transforming the world close at hand.So how did these developments inform ideas of knowledge? If new

Melvyn Bragg and guests discuss one of the most important philosophers of the 20th century, Karl Popper whose ideas about science and politics robustly challenged the accepted ideas of the day. He strongly resisted the prevailing empiricist consensus that scientists' theories could be proved true.Popper wrote: “The more we learn about the world and the deeper our learning, the more conscious, specific and articulate will be our knowledge of what we do not know, our knowledge of our ignorance”. He believed that even when a scientific principle had been successfully and repeatedly tested, it was not necessarily true. Instead it had simply not proved false, yet! This became known as the theory of falsification.He called for a clear demarcation between good science, in which theories are constantly challenged, and what he called “pseudo sciences” which couldn't be tested. His debunking of such ideologies led some to describe him as the “murderer of Freud and Marx”. He went on to apply his ideas to politics, advoc

Melvyn Bragg and guests discuss the Greek mathematician Archimedes. Reputed to have shouted “Eureka!” as he leapt from his bath having discovered the principles of floating bodies. Whatever the truth of the myths surrounding the man, he was certainly one of the world’s great mathematicians. The practical application of his work in pulleys and levers created formidable weapons such as catapults and ship tilting systems, allowing his home city in Sicily to defend itself against the Romans. “Give me a place to stand and I will move the earth”, he declared.But despite these triumphs, his true love remained maths for maths sake. Plutarch writes: “He placed his whole affection and ambition in those purer speculations where there can be no reference to the vulgar needs of life.” His most important breakthroughs came in the field of geometry with his work on the areas and volumes of curved objects.So how did this Greek mathematician in the third century BC arrive at a calculation of Pi? Did he really create a Death

Melvyn Bragg and guests discuss the Jesuits, a Catholic religious order of priests who became known as “the school masters of Europe”. Founded in the 16th century by the soldier Ignatius Loyola, they became a major force throughout the world, from China to South America. “Give us a boy and we will return you a man, a citizen of his country and a child of God”, they declared. By the 17th century there were more than 500 schools established across Europe. Their ideas about a standardised curriculum and teaching became the basis for many education systems today.They were also among the greatest patrons of art in early modern Europe, using murals and theatre to get their message across. To their enemies they were a sinister collective whose influence reached into the courts of kings. Their wealth and their adaptability to local customs abroad provoked suspicion, prompting their eventual suppression in the late 18th century. They were re-established in 1814 and now have more than twenty thousand members.So why was

Melvyn Bragg and guests discuss the planet Mars. Named after the Roman god of war, Mars has been a source of continual fascination. It is one of our nearest neighbours in space, though it takes about a year to get there. It is very inhospitable with high winds racing across extremely cold deserts. But it is spectacular, with the highest volcano in the solar system and a giant chasm that dwarfs the Grand Canyon.For centuries there has been fierce debate about whether there is life on Mars and from the 19th century it was even thought there might be a system of canals on the planet. This insatiable curiosity has been fuelled by writers like HG Wells and CS Lewis and countless sci-fi films about little green men.So what do we know about Mars – its conditions, now and in the past? What is the evidence that there might be water and thus life on Mars? And when might we expect man to walk on its surface?With John Zarnecki, Professor of Space Science at the Open University and a team leader on the ExoMars mission; Co

Melvyn Bragg and guests discuss the contribution Indian mathematicians have made to our understanding of the subject. Mathematics from the Indian subcontinent has provided foundations for much of our modern thinking on the subject. They were thought to be the first to use zero as a number. Our modern numerals have their roots there too. And mathematicians in the area that is now India, Pakistan and Bangladesh were grappling with concepts such as infinity centuries before Europe got to grips with it. There’s even a suggestion that Indian mathematicians discovered Pythagoras’ theorem before Pythagoras. Some of these advances have their basis in early religious texts which describe the geometry necessary for building falcon-shaped altars of precise dimensions. Astronomical calculations used to decide the dates of religious festivals also encouraged these mathematical developments. So how were these advances passed on to the rest of the world? And why was the contribution of mathematicians from this area ignored

Melvyn Bragg and guests discuss the speed of light. Scientists and thinkers have been fascinated with the speed of light for millennia. Aristotle wrongly contended that the speed of light was infinite, but it was the 17th Century before serious attempts were made to measure its actual velocity – we now know that it’s 186,000 miles per second. Then in 1905 Einstein’s Special Theory of Relativity predicted that nothing can travel faster than the speed of light. This then has dramatic effects on the nature of space and time. It’s been thought the speed of light is a constant in Nature, a kind of cosmic speed limit, now the scientists aren’t so sure. With John Barrow, Professor of Mathematical Sciences and Gresham Professor of Astronomy at Cambridge University; Iwan Morus, Senior Lecturer in the History of Science at The University of Wales, Aberystwyth; Jocelyn Bell Burnell, Visiting Professor of Astrophysics at Oxford University.

Melvyn Bragg and guests discuss the Poincaré Conjecture. The great French mathematician Henri Poincaré declared: “The scientist does not study mathematics because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful. If nature were not beautiful, it would not be worth knowing and life would not be worth living. And it is because simplicity, because grandeur, is beautiful that we preferably seek simple facts, sublime facts, and that we delight now to follow the majestic course of the stars.” Poincaré’s ground-breaking work in the 19th and early 20th century has indeed led us to the stars and the consideration of the shape of the universe itself. He is known as the father of topology – the study of the properties of shapes and how they can be deformed. His famous Conjecture in this field has been causing mathematicians sleepless nights ever since. He is also credited as the Father of Chaos Theory.So how did this great polymath change the way we understand the worl

Melvyn Bragg and guests discuss the Needham Question; why Europe and not China developed modern technology. What do these things have in common? Fireworks, wood-block printing, canal lock-gates, kites, the wheelbarrow, chain suspension bridges and the magnetic compass. The answer is that they were all invented in China, a country that, right through the Middle Ages, maintained a cultural and technological sophistication that made foreign dignitaries flock to its imperial courts for trade and favour. But then, around 1700, the flow of ingenuity began to dry up and even reverse as Europe bore the fruits of the scientific revolution back across the globe. Why did Modern Science develop in Europe when China seemed so much better placed to achieve it? This is called the Needham Question, after Joseph Needham, the 20th century British Sinologist who did more, perhaps, than anyone else to try and explain it.But did Joseph Needham give a satisfactory answer to the question that bears his name? Why did China’s early t

Melvyn Bragg and guests discuss the Prussian naturalist and explorer Alexander Von Humboldt. He was possibly the greatest and certainly one of the most famous scientists of the 19th century. Darwin described him as 'the greatest scientific traveller who ever lived'. Goethe declared that one learned more from an hour in his company than eight days of studying books and even Napoleon was reputed to be envious of his celebrity.A friend of Goethe and an influence on Coleridge and Shelly, when Darwin went voyaging on the Beagle it was Humboldt's works he took for inspiration and guidance. At the time of his death in 1859, the year Darwin published On the Origin of Species, Humboldt was probably the most famous scientist in Europe. Add to this shipwrecks, homosexuality and Spanish American revolutionary politics and you have the ingredients for one of the more extraordinary lives lived in Europe (and elsewhere) in the 18th and 19th centuries. But what is Humboldt's true position in the history of science? How did h

Melvyn Bragg and guests discuss the galaxies. Spread out across the voids of space like spun sugar, but harbouring in their centres super-massive black holes. Our galaxy is about 100,000 light years across, is shaped like a fried egg and we travel inside it at approximately 220 kilometres per second. The nearest one to us is much smaller and is nicknamed the Sagittarius Dwarf. But the one down the road, called Andromeda, is just as large as ours and, in 10 billion years, we'll probably crash into it. Galaxies - the vast islands in space of staggering beauty and even more staggering dimension. But galaxies are not simply there to adorn the universe; they house much of its visible matter and maintain the stars in a constant cycle of creation and destruction. But why do galaxies exist, how have they evolved and what lies at the centre of a galaxy to make the stars dance round it at such colossal speeds? With John Gribbin, Visiting Fellow in Astronomy at the University of Sussex; Carolin Crawford, Royal Society U

Melvyn Bragg and guests discuss Carbon. It forms the basis of all organic life and has the amazing ability to bond with itself and a wide range of other elements, forming nearly 10 million known compounds. It is in the food we eat, the clothes we wear, the shampoo we use and the petrol that fuels our cars. Because carbon has the largest range of subtle bonding capabilities, 95% of everything that exists in the universe is made up of carbon atoms that are stuck together. It is an extraordinary element for many reasons: the carbon-nitrogen cycle provides some of the energy produced by the Sun and the stars; it has the highest melting point of all the elements; and its different forms include one of the softest and one of the hardest substances known. What gives carbon its great ability to bond with other atoms? What is the significance of the recent discovery of a new carbon molecule - the C60? What role does carbon play in the modern chemistry of nanotechnology? And how should we address the problem of our dim

Melvyn Bragg and guests discuss the heart. Aristotle considered the heart to be the seat of thought, reason and emotion. The Roman physician Galen located the seat of the passions in the liver, the seat of reason in the brain, and considered the heart to be the seat of the emotions. It was not until the 17th century that the physician William Harvey wrote in the preface to his thesis On the Motion of the Heart and Blood in Animals, a letter addressed to King Charles I. 'The heart of animals is the foundation of their life, the sovereign of everything within them...from which all power proceeds. The King, in like manner, is the foundation of his kingdom, the sun of the world around him, the heart of the republic, the foundation whence all power, all grace doth flow'. Harvey was probably wise to address the King in this manner, for what he laid out in his groundbreaking text challenged scientific wisdom that had gone unquestioned for centuries about the true function of the heart. Organs had been seen in a hi

Melvyn Bragg and guests discuss the relationship between astronomy and the British Empire. The 18th century explorer and astronomer James Cook wrote: 'Ambition leads me not only farther than any other man has been before me, but as far as I think it possible for man to go'. Cook's ambition took him to the far reaches of the Pacific and led to astronomical observations which measured the distance of Venus to the Sun with unprecedented accuracy. Cook's ambition was not just personal and astronomical. It represented the colonial ambition of the British Empire which was linked inextricably with science and trade. The discoveries about the Transit of Venus, made on Cook's voyage to Tahiti, marked the beginning of a period of expansion by the British which relied on maritime navigation based on astronomical knowledge. With Simon Schaffer, Professor in History and Philosophy of Science at the University of Cambridge; Kristen Lippincott, former Director of the Royal Observatory, Greenwich; Allan Chapman, Historian of

Melvyn Bragg and guests discuss the search for immunisation. In 1717, Lady Mary Wortley Montagu, the wife of the British Ambassador to the Ottoman Empire, wrote a letter to her friend describing how she had witnessed the practice of smallpox inoculation in Constantinople. This involved the transfer of material from a smallpox postule into multiple cuts made in a vein. Lady Montagu had lost her brother to smallpox and was amazed that the Middle Eastern practice of inoculation rendered the fatal disease harmless. In Britain, the practice was unknown. Inoculation was an early attempt at creating immunity to disease, but was later dismissed when Edward Jenner pioneered immunisation through vaccination in 1796. Vaccination was hailed a huge success. Napoleon described it as the greatest gift to mankind, but when the British government introduced the compulsory Vaccination Act in 1853, targeted at the poor and the working class, it sparked a mass opposition movement.How did a Gloucestershire country surgeon become

Melvyn Bragg and guests discuss the formation of the Royal Society. In the 17th century the natural philosopher Francis Bacon heralded the new age of science. The frontispiece to his 1620 edition of the Instauratio Magna depicted a galleon travelling between the metaphorical Pillars of Hercules thought to lie at the Strait of Gibraltar and believed to mark the end of the known world. The image encapsulated Bacon's desire to sail beyond the limits set by Aristotle and the curriculum of the Ancient universities towards the new continent of science. Bacon imagined practical scientists engaged in a collaborative effort to expand knowledge of the natural world. But it was not until the turbulence of the Civil War and Commonwealth years had passed that such a group of scientists would gather together in London for this purpose, and form the Royal Society. Amongst its members were Robert Boyle, Robert Hooke, Christopher Wren and Isaac Newton, who explicitly rejected dogma and insisted on practical experimentation an

Melvyn Bragg and guests discuss negative numbers, a history of mystery and suspicion. In 1759 the British mathematician Francis Maseres wrote that negative numbers "darken the very whole doctrines of the equations and make dark of the things which are in their nature excessively obvious and simple". Because of their dark and mysterious nature, Maseres concluded that negative numbers did not exist, as did his contemporary, William Friend. However, other mathematicians were braver. They took a leap into the unknown and decided that negative numbers could be used during calculations, as long as they had disappeared upon reaching the solution. The history of negative numbers is one of stops and starts. The trailblazers were the Chinese who by 100 BC were able to solve simultaneous equations involving negative numbers. The Ancient Greeks rejected negative numbers as absurd, by 600 AD, the Indians had written the rules for the multiplication of negative numbers and 400 years later, Arabic mathematicians realised th

Melvyn Bragg and guests discuss the story of human evolution, which stretches back over six million years. It is not the story of one species but of several diverse species, some of whom walked the Earth at the same time. From the earliest hominids to the early Homo sapiens, there was nothing inevitable about the course of human evolution. But what conditions created the opportunity for diverse human species to thrive? What environmental factors led to the survival of one human species, but contributed to the extinction of so many others? What can the fossil record and the science of genetics tell us about our ancestors? How does the brain make modern man so unique in the natural world? With Steve Jones, Professor of Genetics in the Galton Laboratory at University College London; Fred Spoor, Professor of Evolutionary Anatomy at University College London; Margaret Clegg, Honorary Research Fellow in the Department of Biological Anthropology at University College London.

Melvyn Bragg and guests discuss relativism, a philosophy of shifting sands. "Today, a particularly insidious obstacle to the task of educating is the massive presence in our society and culture of that relativism which, recognizing nothing as definitive, leaves as the ultimate criterion only the self with its desires. And under the semblance of freedom it becomes a prison for each one, for it separates people from one another, locking each person into his or her own 'ego'." Pope Benedict XVI, in a speech given in June 2005, showed that the issue of relativism is as contentious today as it was in Ancient Greece, when Plato took on the relativist stance of Protagoras and the sophists. Relativism is a school of philosophical thought which holds to the idea that there are no absolute truths. Instead, truth is situated within different frameworks of understanding that are governed by our history, culture and critical perspective. Why has relativism so radically divided scholars and moral custodians over the centur