254 episodes

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

In Our Time: Science BBC

    • History

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

    Solar Wind

    Solar Wind

    Melvyn Bragg and guests discuss the flow of particles from the outer region of the Sun which we observe in the Northern and Southern Lights, interacting with Earth's magnetosphere, and in comet tails that stream away from the Sun regardless of their own direction. One way of defining the boundary of the solar system is where the pressure from the solar wind is balanced by that from the region between the stars, the interstellar medium. Its existence was suggested from the C19th and Eugene Parker developed the theory of it in the 1950s and it has been examined and tested by a series of probes in C20th up to today, with more planned.

    With

    Andrew Coates
    Professor of Physics and Deputy Director in charge of the Solar System at the Mullard Space Science Laboratory, University College London

    Helen Mason OBE
    Reader in Solar Physics at the Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Fellow at St Edmund's College

    And

    Tim Horbury
    Professor of Physics at Imperial College London

    Producer: Simon Tillotson

    • 55 min
    Hybrids

    Hybrids

    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 Knapp
    Tropical Botanist at the Natural History Museum

    Nicola Nadeau
    Lecturer in Evolutionary Biology at the University of Sheffield

    And

    Steve Jones
    Senior Research Fellow in Genetics at University College London

    Producer: Simon Tillotson

    • 50 min
    Dorothy Hodgkin

    Dorothy Hodgkin

    Melvyn Bragg and guests discuss the work and ideas of Dorothy Crowfoot Hodgkin (1910-1994), awarded the Nobel Prize in Chemistry in 1964 for revealing the structures of vitamin B12 and penicillin and who later determined the structure of insulin. She was one of the pioneers of X-ray crystallography and described by a colleague as 'a crystallographers' crystallographer'. She remains the only British woman to have won a Nobel in science, yet rejected the idea that she was a role model for other women, or that her career was held back because she was a woman. She was also the first woman since Florence Nightingale to receive the Order of Merit, and was given the Lenin Peace Prize in recognition of her efforts to bring together scientists from the East and West in pursuit of nuclear disarmament.

    With

    Georgina Ferry
    Science writer and biographer of Dorothy Hodgkin

    Judith Howard
    Professor of Chemistry at Durham University

    and

    Patricia Fara
    Fellow of Clare College, Cambridge

    Producer: Simon Tillotson

    • 52 min
    Kinetic Theory

    Kinetic Theory

    Melvyn Bragg and guests discuss how scientists sought to understand the properties of gases and the relationship between pressure and volume, and what that search unlocked. Newton theorised that there were static particles in gases that pushed against each other all the harder when volume decreased, hence the increase in pressure. Those who argued that molecules moved, and hit each other, were discredited until James Maxwell and Ludwig Boltzmann used statistics to support this kinetic theory. Ideas about atoms developed in tandem with this, and it came as a surprise to scientists in C20th that the molecules underpinning the theory actually existed and were not simply thought experiments.

    The image above is of Ludwig Boltzmann from a lithograph by Rudolf Fenzl, 1898

    With

    Steven Bramwell
    Professor of Physics at University College London

    Isobel Falconer
    Reader in History of Mathematics at the University of St Andrews

    and

    Ted Forgan
    Emeritus Professor of Physics at the University of Birmingham

    Producer: Simon Tillotson

    • 51 min
    The Evolution of Teeth

    The Evolution of Teeth

    Melvyn Bragg and guests discuss theories about the origins of teeth in vertebrates, and what we can learn from sharks in particular and their ancestors. Great white sharks can produce up to 100,000 teeth in their lifetimes. For humans, it is closer to a mere 50 and most of those have to last from childhood. Looking back half a billion years, though, the ancestors of sharks and humans had no teeth in their mouths at all, nor jaws. They were armoured fish, sucking in their food. The theory is that either their tooth-like scales began to appear in mouths as teeth, or some of their taste buds became harder. If we knew more about that, and why sharks can regenerate their teeth, then we might learn how humans could grow new teeth in later lives.

    With

    Gareth Fraser
    Assistant Professor in Biology at the University of Florida

    Zerina Johanson
    Merit Researcher in the Department of Earth Sciences at the Natural History Museum

    and

    Philip Donoghue
    Professor of Palaeobiology at the University of Bristol

    Producer: Simon Tillotson

    • 49 min
    Pheromones

    Pheromones

    Melvyn Bragg and guests discuss how members of the same species send each other invisible chemical signals to influence the way they behave. Pheromones are used by species across the animal kingdom in a variety of ways, such as laying trails to be followed, to raise the alarm, to scatter from predators, to signal dominance and to enhance attractiveness and, in honey bees, even direct development into queen or worker.

    The image above is of male and female ladybirds that have clustered together in response to pheromones.

    With

    Tristram Wyatt
    Senior Research Fellow at the Department of Zoology at the University of Oxford

    Jane Hurst
    William Prescott Professor of Animal Science at the University of Liverpool

    and

    Francis Ratnieks
    Professor of Apiculture and Head of the Laboratory of Apiculture and Social Insects at the University of Sussex

    Producer: Simon Tillotson

    • 49 min

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