In Our Time: Science

Melvyn Bragg and guests discuss how some bats, dolphins and other animals emit sounds at high frequencies to explore their environments, rather than sight. This was such an unlikely possibility, to natural historians from C18th onwards, that discoveries were met with disbelief even into the C20th; it was assumed that bats found their way in the dark by touch. Not all bats use echolocation, but tho...

Melvyn Bragg and guests discuss the discovery and growing understanding of the Proton, formed from three quarks close to the Big Bang and found in the nuclei of all elements. The positive charges they emit means they attract the fundamental particles of negatively charged electrons, an attraction that leads to the creation of atoms which in turn leads to chemistry, biology and life itself. The Sun...

In a programme first broadcast on April 12th 2018, Melvyn Bragg and guests discuss the contribution of George Stephenson (1781-1848) and his son Robert (1803-59) to the development of the railways in C19th. George became known as The Father of Railways and yet arguably Robert's contribution was even greater, with his engineering work going far beyond their collaboration. Robert is credited with th...

Melvyn Bragg and guests discuss the pioneering scientist Rosalind Franklin (1920 - 1958). During her distinguished career, Franklin carried out ground-breaking research into coal and viruses but she is perhaps best remembered for her investigations in the field of DNA. In 1952 her research generated a famous image that became known as Photograph 51. When the Cambridge scientists Francis Crick and...

Melvyn Bragg and guests discuss fungi. These organisms are not plants or animals but a kingdom of their own. Millions of species of fungi live on the Earth and they play a crucial role in ecosystems, enabling plants to obtain nutrients and causing material to decay. Without fungi, life as we know it simply would not exist. They are also a significant part of our daily life, making possible the pro...

The octopus, the squid, the nautilus and the cuttlefish are some of the most extraordinary creatures on this planet, intelligent and yet apparently unlike other life forms. They are cephalopods and are part of the mollusc family like snails and clams, and they have some characteristics in common with those. What sets them apart is the way members of their group can change colour, camouflage themse...

In a programme first broadcast in 2017, Melvyn Bragg and guests discuss Gauss (1777-1855), widely viewed as one of the greatest mathematicians of all time. He was a child prodigy, correcting his father's accounts before he was 3, dumbfounding his teachers with the speed of his mental arithmetic, and gaining a wealthy patron who supported his education. He wrote on number theory when he was 21, wit...

After 27 years, Melvyn Bragg has decided to step down from the In Our Time presenter’s chair. With over a thousand episodes to choose from, he has selected just six that capture the huge range and depth of the subjects he and his experts have tackled. In this sixth of his choices, we hear Melvyn Bragg and his guests in 2017 discussing new discoveries about dinosaurs. Their topic is the development...

After 27 years, Melvyn Bragg has decided to step down from the In Our Time presenter’s chair. With over a thousand episodes to choose from, he has selected just six that capture the huge range and depth of the subjects he and his experts have tackled. In this fourth of his choices, we hear Melvyn Bragg and his guests discuss bird migration. Their topic includes why some birds migrate and others do...

Melvyn Bragg and guests discuss enzymes, the proteins that control the speed of chemical reactions in living organisms. Without enzymes, these reactions would take place too slowly to keep organisms alive: with their actions as catalysts, changes which might otherwise take millions of years can happen hundreds of times a second. Some enzymes break down large molecules into smaller ones, like the o...

Melvyn Bragg and guests discuss the life and work of Louis Pasteur (1822-1895) and his extraordinary contribution to medicine and science. It is said few people have saved more lives than Pasteur. A chemist, he showed that otherwise identical molecules could exist as 'left' and 'right-handed' versions and that molecules produced by living things were always left-handed. He proposed a germ theory t...

After 27 years, Melvyn Bragg has decided to step down from the In Our Time presenter’s chair. With over a thousand episodes to choose from, he has selected just six that capture the huge range and depth of the subjects he and his experts have tackled. In this fifth of his choices, we hear Melvyn Bragg and his guests discuss a key figure from quantum mechanics. Their topic is the life and ideas of...

Melvyn Bragg and guests discuss the high temperatures that marked the end of the Paleocene and start of the Eocene periods, about 50m years ago. Over c1000 years, global temperatures rose more than 5 C on average and stayed that way for c100,000 years more, with the surface of seas in the Arctic being as warm as those in the subtropics. There were widespread extinctions, changes in ocean currents,...

Melvyn Bragg and guests discuss the Kuiper Belt, a vast region of icy objects at the fringes of our Solar System, beyond Neptune, in which we find the dwarf planet Pluto and countless objects left over from the origins of the solar system, some of which we observe as comets. It extends from where Neptune is, which is 30 times further out than the Earth is from the Sun, to about 500 times the Earth...

Melvyn Bragg and guests discuss the flourishing of maths in the early Islamic world, as thinkers from across the region developed ideas in places such as Baghdad's House of Wisdom. Among them were the Persians Omar Khayyam, who worked on equations, and Al-Khwarizmi, latinised as Algoritmi and pictured above, who is credited as one of the fathers of algebra, and the Jewish scholar Al-Samawal, who c...

Melvyn Bragg and guests discuss the relationship between parasites and hosts, where one species lives on or in another to the benefit of the parasite but at a cost to the host, potentially leading to disease or death of the host. Typical examples are mistletoe and trees, hookworms and vertebrates, cuckoos and other birds. In many cases the parasite species do so well in or on a particular host tha...

Melvyn Bragg and guests discuss the German astronomer Johannes Kepler (1571 - 1630). Although he is overshadowed today by Isaac Newton and Galileo, he is considered by many to be one of the greatest scientists in history. The three laws of planetary motion Kepler developed transformed people's understanding of the Solar System and laid the foundations for the revolutionary ideas Isaac Newton produ...

The scientist John Dalton was born in North England in 1766. Although he came from a relatively poor Quaker family, he managed to become one of the most celebrated scientists of his age. Through his work, he helped to establish Manchester as a place where not only products were made but ideas were born. His reputation during his lifetime was so high that unusually a statue was erected to him befor...

Melvyn Bragg and guests discuss plasma, the fourth state of matter after solid, liquid and gas. As over ninety-nine percent of all observable matter in the Universe is plasma, planets like ours, with so little plasma and so much solid, liquid and gas, appear all the more remarkable. On the grand scale, plasma is what the Sun is made from and, when we look into the night sky, almost everything we c...

After 27 years, Melvyn Bragg has decided to step down from the In Our Time presenter’s chair. With over a thousand episodes to choose from, he has selected just six that capture the huge range and depth of the subjects he and his experts have tackled. In this third of his choices, we hear Melvyn Bragg and his guests discuss Greek philosophy. Their topic is Zeno of Elea, a pre-Socratic philosopher...

Melvyn Bragg and guests discuss the development of photography in the 1830s, when techniques for 'drawing with light' evolved to the stage where, in 1839, both Louis Daguerre and William Henry Fox Talbot made claims for its invention. These followed the development of the camera obscura, and experiments by such as Thomas Wedgwood and Nicéphore Niépce, and led to rapid changes in the 1840s as more...

Melvyn Bragg and guests discuss penicillin, discovered by Alexander Fleming in 1928. It is said he noticed some blue-green penicillium mould on an uncovered petri dish at his hospital laboratory, and that this mould had inhibited bacterial growth around it. After further work, Fleming filtered a broth of the mould and called that penicillin, hoping it would be useful as a disinfectant. Howard Flor...

Melvyn Bragg and guests discuss Euclid's Elements, a mathematical text book attributed to Euclid and in use from its appearance in Alexandria, Egypt around 300 BC until modern times, dealing with geometry and number theory. It has been described as the most influential text book ever written. Einstein had a copy as a child, which he treasured, later saying "If Euclid failed to kindle your youthful...

Melvyn Bragg and guests discuss the impact of the eruption of Mt Tambora, in 1815, on the Indonesian island of Sambawa. This was the largest volcanic eruption in recorded history and it had the highest death toll, devastating people living in the immediate area. Tambora has been linked with drastic weather changes in North America and Europe the following year, with frosts in June and heavy rains...

Melvyn Bragg and guests discuss the neutron, one of the particles found in an atom's nucleus. Building on the work of Ernest Rutherford, the British physicist James Chadwick won the Nobel Prize for Physics for his discovery of the neutron in 1932. Neutrons play a fundamental role in the universe and their discovery was at the heart of developments in nuclear physics in the first half of the 20th c...