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In Our Time: Science

Scientific principles, theory, and the role of key figures in the advancement of science.

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The Universe's Shape

Melvyn Bragg and guests discuss the shape of the universe. In the Beginning, runs one account, was the Big Bang. All matter in existence today originated around 13 billion years ago in a phenomenally hot, extraordinarily condensed primordial atom that exploded with incredible force. Hydrogen and helium were shot across the firmament, gravity caused the gases to condense into clouds and in these clouds the first stars were formed, then galaxies came and more galaxies in clusters, onwards and outwards, ever expanding. It is still expanding, runs the orthodox account, and may even be speeding up. It is still creating new galaxies and it continues to colonise more and more of infinite space, despite the fact that it is supposedly infinite itself.So, if our universe is expanding, what is it expanding into? If it is already infinite how can it be getting any bigger? And is there really only one?With Sir Martin Rees, Royal Society Research Professor in Astronomy and Physics, Cambridge University; Julian Barbour, Independent Theoretical Physicist; Janna Levin, Advanced Fellow in Theoretical Physics at the University of Cambridge.


7 Feb 2002

Rank #1

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The Cambrian Period

Melvyn Bragg and guests discuss the Cambrian period when there was an explosion of life on Earth. In the Selkirk Mountains of British Columbia in Canada, there is an outcrop of limestone shot through with a seam of fine dark shale. A sudden mudslide into shallow water some 550 million years ago means that a startling array of wonderful organisms has been preserved within it. Wide eyed creatures with tentacles below and spines on their backs, things like flattened rolls of carpet with a set of teeth at one end, squids with big lobster-like arms. There are thousands of them and they seem to testify to a time when evolution took a leap and life on this planet suddenly went from being small, simple and fairly rare to being large, complex, numerous and dizzyingly diverse. It happened in the Cambrian Period and it's known as the Cambrian Explosion.But if this is the great crucible of life on Earth, what could have caused it? How do the strange creatures relate to life as we see it now? And what does the Cambrian Explosion tell us about the nature of evolution?With Simon Conway Morris, Professor of Evolutionary Palaeobiology, Cambridge University; Richard Corfield, Visiting Senior Lecturer at the Centre for Earth, Planetary, Space and Astronomical Research, Open University; Jane Francis, Professor of Palaeoclimatology, University of Leeds.


17 Feb 2005

Rank #2

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Circadian Rhythms

Melvyn Bragg and his guests discuss the evolution and role of Circadian Rhythms, the so-called body clock that influences an organism's daily cycle of physical, behavioural and mental changes. The rhythms are generated within organisms and also in response to external stimuli, mainly light and darkness. They are found throughout the living world, from bacteria to plants, fungi to animals and, in humans, are noticed most clearly in sleep patterns. WithRussell FosterProfessor of Circadian Neuroscience at the University of OxfordDebra SkeneProfessor of Neuroendocrinology at the University of SurreyAndSteve JonesEmeritus Professor of Genetics at University College London.


17 Dec 2015

Rank #3

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The Royal Society and British Science: Episode 1

As part of the BBC's year of science programming, Melvyn Bragg looks at the history of the oldest scientific learned society of them all: the Royal Society. Melvyn travels to Wadham College, Oxford, where under the shadow of the English Civil War, the young Christopher Wren and friends experimented in the garden of their inspirational college warden, John Wilkins. Back in London, as Charles II is brought to the throne from exile, the new Society is formally founded one night in Gresham College. When London burns six years later, it is two of the key early Fellows of the Society who are charged with its rebuilding. And, as Melvyn finds out, in the secret observatory in The Monument to the fire, it is science which flavours their plans.


4 Jan 2010

Rank #4

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Random and Pseudorandom

Melvyn Bragg and his guests discuss randomness and pseudorandomness.Randomness is the mathematics of the unpredictable. Dice and roulette wheels produce random numbers: those which are unpredictable and display no pattern. But mathematicians also talk of 'pseudorandom' numbers - those which appear to be random but are not. In the last century random numbers have become enormously useful to statisticians, computer scientists and cryptographers. But true randomness is difficult to find, and mathematicians have devised many ingenious solutions to harness or simulate it. These range from the Premium Bonds computer ERNIE (whose name stands for Electronic Random Number Indicator Equipment) to new methods involving quantum physics.Digital computers are incapable of behaving in a truly random fashion - so instead mathematicians have taught them how to harness pseudorandomness. This technique is used daily by weather forecasters, statisticians, and computer chip designers - and it's thanks to pseudorandomness that secure credit card transactions are possible.With:Marcus du SautoyProfessor of Mathematics at the University of OxfordColva Roney-DougalSenior Lecturer in Pure Mathematics at the University of St AndrewsTimothy GowersRoyal Society Research Professor in Mathematics at the University of CambridgeProducer: Thomas Morris.


13 Jan 2011

Rank #5

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The Poincaré Conjecture

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 world and indeed the universe? Why did his conjecture remain unproved for almost a century? And has it finally been cracked?With June Barrow-Green, Lecturer in the History of Mathematics at the Open University; Ian Stewart, Professor of Mathematics at the University of Warwick; Marcus du Sautoy, Professor of Mathematics at the University of Oxford.


2 Nov 2006

Rank #6

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The Nervous System

Melvyn Bragg and his guests discuss the nervous system.Most animals have a nervous system, a network of nerve tissues which allows parts of the body to communicate with each other. In humans the most significant parts of this network are the brain, spinal column and retinas, which together make up the central nervous system. But there is also a peripheral nervous system, which enables sensation, movement and the regulation of the major organs.Scholars first described the nerves of the human body over two thousand years ago. For 1400 years it was believed that they were animated by 'animal spirits', mysterious powers which caused sensation and movement. In the eighteenth century scientists discovered that nerve fibres transmitted electrical impulses; it was not until the twentieth century that chemical agents - neurotransmitters - were first identified.With:Colin BlakemoreProfessor of Neuroscience at the University of OxfordVivian NuttonEmeritus Professor of the History of Medicine at University College, LondonTilli TanseyProfessor of the History of Modern Medical Sciences at Queen Mary, University of London.Producer: Thomas Morris.


10 Feb 2011

Rank #7

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Darwin: On the Origins of Charles Darwin

To celebrate the 200th anniversary of the birth of Charles Darwin in 2009 and the 150th anniversary of the publication of On the Origin of Species, Melvyn Bragg presents a series about Darwin's life and work.Melvyn tells the story of Darwin's early life in Shropshire and discusses the significance of the three years he spent at Cambridge, where his interests shifted from religion to natural science.Featuring contributions from Darwin biographer Jim Moore, geneticist at University College London Steve Jones, fellow of Christ's College Cambridge David Norman and assistant librarian at Christ's College Cambridge Colin Higgins.


5 Jan 2009

Rank #8

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In 1977, scientists in the submersible "Alvin" were exploring the deep ocean bed off the Galapagos Islands. In the dark, they discovered hydrothermal vents, like chimneys, from which superheated water flowed. Around the vents there was an extraordinary variety of life, feeding on microbes which were thriving in the acidity and extreme temperature of the vents. While it was already known that some microbes are extremophiles, thriving in extreme conditions, such as the springs and geysers of Yellowstone Park (pictured), that had not prepared scientists for what they now found. Since the "Alvin" discovery, the increased study of extremophile microbes has revealed much about what is and is not needed to sustain life on Earth and given rise to new theories about how and where life began. It has also suggested forms and places in which life might be found elsewhere in the Universe. With Monica GradyProfessor of Planetary and Space Sciences at the Open UniversityIan CrawfordProfessor of Planetary Science and Astrobiology at Birkbeck University of LondonAndNick LaneReader in Evolutionary Biochemistry at University College LondonProducer: Simon Tillotson.


25 Jun 2015

Rank #9

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The Curies

Melvyn Bragg and his guests discuss the scientific achievements of the Curie family. In 1903 Marie and Pierre Curie shared a Nobel Prize in Physics with Henri Becquerel for their work on radioactivity, a term which Marie coined. Marie went on to win a Nobel in Chemistry eight years later; remarkably, her daughter Irène Joliot-Curie would later share a Nobel with her husband Frédéric Joliot-Curie for their discovery that it was possible to create radioactive materials in the laboratory. The work of the Curies added immensely to our knowledge of fundamental physics and paved the way for modern treatments for cancer and other illnesses.With:Patricia FaraSenior Tutor of Clare College, University of CambridgeRobert FoxEmeritus Professor of the History of Science at the University of OxfordSteven T BramwellProfessor of Physics and former Professor of Chemistry at University College LondonProducer: Simon Tillotson.


26 Mar 2015

Rank #10

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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, advocating an Open Society. His ideas influenced a wide range of politicians, from those close to Margaret Thatcher, to thinkers in the Eastern Communist bloc and South America.So how did Karl Popper change our approach to the philosophy of science? How have scientists and philosophers made use of his ideas? And how are his theories viewed today? Are we any closer to proving scientific principles are “true”?With John Worrall, Professor of Philosophy of Science at the London School of Economics; Anthony O'Hear, Weston Professor of Philosophy at Buckingham University; Nancy Cartwright, Professor of Philosophy at the LSE and the University of California


8 Feb 2007

Rank #11

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Melvyn Bragg and his guests discuss Einstein's theories of relativity. Between 1905 and 1917 Albert Einstein formulated a theoretical framework which transformed our understanding of the Universe. The twin theories of Special and General Relativity offered insights into the nature of space, time and gravitation which changed the face of modern science. Relativity resolved apparent contradictions in physics and also predicted several new phenomena, including black holes. It's regarded today as one of the greatest intellectual achievements of the twentieth century, and had an impact far beyond the world of science.With:Ruth GregoryProfessor of Mathematics and Physics at Durham UniversityMartin ReesAstronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of CambridgeRoger PenroseEmeritus Rouse Ball Professor of Mathematics at the University of Oxford.Producer: Thomas Morris.


6 Jun 2013

Rank #12

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Melvyn Bragg and guests discuss what happens when parents from different species have offspring, despite their genetic differences. In some cases, such as the zebra/donkey hybrid in the image above, the offspring are usually infertile but in others the genetic change can lead to new species with evolutionary advantages. Hybrids can occur naturally, yet most arise from human manipulation and Darwin's study of plant and animal domestication informed his ideas on natural selection.With Sandra KnappTropical Botanist at the Natural History MuseumNicola NadeauLecturer in Evolutionary Biology at the University of SheffieldAndSteve JonesSenior Research Fellow in Genetics at University College LondonProducer: Simon Tillotson


31 Oct 2019

Rank #13

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Grand Unified Theory

Melvyn Bragg examines 20th century physics’ quest for the ultimate theory of everything. Einstein left us with his theory of General Relativity, which explained how gravity works on the scale of stars, galaxies, and the universe itself and Schroedinger left us with the equation that explained the mechanics of the tiny quantum realm. Both theories work to wonderful effect in their own worlds, but (and this is the sticking point) gravity is strangely absent from the quantum realm and planets behave nothing like particles. The enigma for scientists throughout most of the last century is that, as they are currently formulated, general relativity and quantum mechanics cannot both be right. The history of twentieth century physics has been a struggle to find a way to unite them, to find what has become the holy grail of modern physics: The Grand Unified Theory. With Brian Greene, Professor of Physics and Mathematics, Columbia University and Cornell University; Sir Martin Rees, Astronomer Royal and Royal Society Research Professor in Astronomy and Physics at Cambridge University.


24 Feb 2000

Rank #14

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Game Theory

Melvyn Bragg and his guests discuss game theory, the mathematical study of decision-making. First formulated in the 1940s, the discipline entails devising 'games' to simulate situations of conflict or cooperation. It allows researchers to unravel decision-making strategies, and even to establish why certain types of behaviour emerge. Some of the games studied in game theory have become well known outside academia - they include the Prisoner's Dilemma, an intriguing scenario popularised in novels and films, and which has inspired television game shows. Today game theory is seen as a vital tool in such diverse fields as evolutionary biology, economics, computing and philosophy. With:Ian StewartEmeritus Professor of Mathematics at the University of WarwickAndrew ColmanProfessor of Psychology at the University of LeicesterRichard BradleyProfessor of Philosophy at the London School of Economics and Political Science.Producer: Thomas Morris.


10 May 2012

Rank #15

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Artificial Intelligence

Melvyn Bragg and guests discuss artificial intelligence. Can machines think? It was a question posed by the mathematician and Bletchley Park code breaker Alan Turing and it is a question still being asked today. What is the difference between men and machines and what does it mean to be human? And if we can answer that question, is it possible to build a computer that can imitate the human mind? There are those who have always had robust answers to the questions that those who seek to create artificial intelligence have posed. In 1949 the eminent neurosurgeon, Professor Geoffrey Jefferson argued that the mechanical mind could never rival a human intelligence because it could never be conscious of what it did: "Not until a machine can write a sonnet or compose a concerto because of thoughts and emotions felt", he declared "and not by the chance fall of symbols, could we agree that machine equals brain - that is, not only write it but know that it had written it." Yet the quest rolled on for machines that were bigger and better at processing symbols and calculating infinite permutations. Who were the early pioneers of artificial intelligence and what drove them to imitate the operations of the human mind? Is intelligence the defining characteristic of humanity? And how has the quest for artificial intelligence been driven by warfare and conflict in the twentieth century? With Jon Agar, Lecturer in the History and Philosophy of Science, University of Cambridge; Alison Adam, Professor of Information Systems, Salford University; Igor Aleksander, Professor of Neural Systems Engineering at Imperial College, University of London.


8 Dec 2005

Rank #16

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Human Evolution

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.


16 Feb 2006

Rank #17

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Aristotle's Biology

Melvyn Bragg and guests discuss the remarkable achievement of Aristotle (384-322BC) in the realm of biological investigation, for which he has been called the originator of the scientific study of life. Known mainly as a philosopher and the tutor for Alexander the Great, who reportedly sent him animal specimens from his conquests, Aristotle examined a wide range of life forms while by the Sea of Marmara and then on the island of Lesbos. Some ideas, such as the the spontaneous generation of flies, did not survive later scrutiny, yet his influence was extraordinary and his work was unequalled until the early modern period.The image above is of the egg and embryo of a dogfish, one of the animals Aristotle described accurately as he recorded their development.WithArmand LeroiProfessor of Evolutionary Development Biology at Imperial College LondonMyrto HatzimichaliLecturer in Classics at the University of CambridgeAndSophia ConnellLecturer in Philosophy at Birkbeck, University of LondonProducer: Simon Tillotson


7 Feb 2019

Rank #18

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Darwin: On the Origin of Species

To celebrate the 200th anniversary of the birth of Charles Darwin and the 150th anniversary of the publication of On the Origin of Species, Melvyn Bragg presents a series about Darwin's life and work.How Darwin was eventually persuaded to publish On the Origin of Species in November 1859 and the book's impact on fellow scientists and the general public.Featuring contributions from Darwin biographer Jim Moore, Steve Jones, geneticist at University College London, Jim Secord of the Darwin Correspondence Project and Johannes Vogel, Sandy Knapp and Judith Magee, all of the National History Museum.


7 Jan 2009

Rank #19

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The Multiverse

Melvyn Bragg and guests will be leaving the studio, the planet and indeed, the universe to take a tour of the Multiverse. If you look up the word ‘universe’ in the Oxford English Dictionary you will find the following definition: “The whole of created or existing things regarded collectively; all things (including the earth, the heavens, and all the phenomena of space) considered as constituting a systematic whole.” That sounds fairly comprehensive as a description of everything, but for an increasing number of physicists and cosmologists the universe is not enough. They talk of a multiverse – literally many universes – to explain aspects of their theory, the character of the universe and the riddle of our existence within it. Indeed, compared to the scope and complexity of the multiverse, the whole of our known reality may be as a speck of sand upon a beach.The idea of a multiverse is still controversial, some argue that it isn’t even science, because it is based on an idea that we may never be able to prove or even see. But what might a multiverse be like, why are physicists and cosmologists increasingly interested in it and is it really scientific to discuss the existence of universes we may never know anything With Martin Rees, President of the Royal Society and Professor of Cosmology and Astrophysics at the University of Cambridge; Fay Dowker, Reader in Theoretical Physics at Imperial College; Bernard Carr, Professor of Mathematics and Astronomy at Queen Mary, University of London


21 Feb 2008

Rank #20