Misha Glenny and guests discuss one of the wonders of the natural world. In 1875 in the western Pacific, the crew of HMS Challenger discovered the Mariana Trench which turned out to be deeper than Everest is high, by two kilometres. Trenches like Mariana form when one tectonic plate slips under another and heads down and there are around fifty of them globally. While at one time some thought it…
Melvyn Bragg and guests discuss the evolution of lungs and of the first breaths, which can be traced back 400 million years to when animal life spread from rock pools and swamps onto land, as some fish found an evolutionary advantage in getting their oxygen from air rather than water. Breathing with lungs may have started with fish filling their mouths with air and forcing it down into sacs in…
Melvyn Bragg and guests discuss the decisive role of one of the great 20th Century physicists in solving the question of nuclear fission. It is said that Meitner (1878-1968) made this breakthrough over Christmas 1938 while she was sitting on a log in Sweden during a snowy walk with her nephew Otto Frisch (1904-79). Both were Jewish-Austrian refugees who had only recently escaped from Nazi Germany.…
Since plants have to mate and produce offspring while rooted to the spot, they have to be pollinated – by wind, water, or animals – most commonly insects. They use a surprising array of tricks to attract pollinators: striking colours, iridescent light effects, and enticing scents, to name but a few. Insects, on the other hand, do not seek to pollinate plants – they are looking for food; so plants…
Melvyn Bragg and guests discuss slime mould, a basic organism that grows on logs, cowpats and compost heaps. Scientists have found difficult to categorise slime mould: in 1868, the biologist Thomas Huxley asked: ‘Is this a plant, or is it an animal? Is it both or is it neither?’ and there is a great deal scientists still don’t know about it. But despite not having a brain, slime mould can solve…
Melvyn Bragg and guests discuss some of the great unanswered questions in science: how and where did life on Earth begin, what did it need to thrive and could it be found elsewhere? Charles Darwin speculated that we might look for the cradle of life here in 'some warm little pond'; more recently the focus moved to ocean depths, while new observations in outer space and in laboratories raise fresh…
Melvyn Bragg and guests discuss the 2000-year-old device which transformed our understanding of astronomy in ancient Greece. In 1900 a group of sponge divers found the wreck of a ship off the coast of the Greek island of Antikythera. Among the items salvaged was a corroded bronze object, the purpose of which was not at first clear. It turned out to be one of the most important discoveries in…
Melvyn Bragg and guests discuss the tantalising idea that there are shortcuts between distant galaxies, somewhere out there in the universe. The idea emerged in the context of Einstein's theories and the challenge has been not so much to prove their unlikely existence as to show why they ought to be impossible. The universe would have to folded back on itself in places, and there would have to be…
Melvyn Bragg and guests discuss the most abundant lifeform on Earth: the viruses that 'eat' bacteria. Early in the 20th century, scientists noticed that something in their Petri dishes was making bacteria disappear and they called these bacteriophages, things that eat bacteria. From studying these phages, it soon became clear that they offered countless real or potential benefits for understanding…
Melvyn Bragg and guests discuss the planet which is closest to our Sun. We see it as an evening or a morning star, close to where the Sun has just set or is about to rise, and observations of Mercury helped Copernicus understand that Earth and the other planets orbit the Sun, so displacing Earth from the centre of our system. In the 20th century, further observations of Mercury helped Einstein…