Aluminium and strontium

05/25/20 • 26 min

Andrea Sella, Professor of Inorganic Chemistry at University College London, celebrates the art and science of the chemical elements. Today he looks at aluminium and strontium, elements that give us visual treats.

At the time of Emperor Napoleon the Third in 19th century France aluminium was more valuable than gold and silver. The Emperor liked the metal so much he had his cutlery made out of it. But once a cheaper way was discovered to extract aluminium it began to be used for all kinds of objects, from aeroplanes to coffee pots. Andrea talks to Professor Mark Miodownik at the Institute of Making at UCL about why aluminium is such a useful material, from keeping crisps crisp to the tinsel on our Christmas trees. And he talks about the lightness of bicycles made from aluminium with Keith Noronha, of Reynolds Technology.

Strontium is the 15th most common element in the earth yet we really only come into contact with it in fireworks. It gives us the deep red colour we admire in a pyrotechnics display. Andrea meets Mike Sansom of Brighton Fireworks who explains how a firework is constructed and reveals the chemical mix that creates the bright red flashes.

Professor Thomas Klapötke of the Ludwig-Maximilians University in Munich talks about his search for a substitute for strontium in fireworks and about how the element can get into our bones. Rupert Cole at the Science Museum in London shows Andrea how Humphry Davy was the first to extract strontium from rocks found in Scotland.

And Janet Montgomery, Professor of Archaeology at Durham University, explains how strontium traces have revealed that our Neolithic ancestors moved around much more than was previously thought. Nearly half the people buried around Stonehenge in Southern England were born in places with different rocks from those under Salisbury Plain in Southern England.

Picture: Fireworks, credit: rzelich/Getty Images

Picture: Fireworks, credit: rzelich/Getty Images

Previous Episode

Gold and silver

Andrea Sella, Professor of Inorganic Chemistry at University College London, celebrates the art and science of chemical elements. In this episode he looks at two elements we have valued for millennia – gold and silver.

Nina Gilbey at the London Jewellery Workshop teaches him how to work the metal and make a silver ring, and Rupert Cole, Curator of Chemistry at the Science Museum, shows him the handiwork of silversmiths who fashioned an elaborate microscope for King George the Third and a silver thimble that was used (with some zinc and a few drops of an acid) to generate an electric current that was sent through a transatlantic telegraph cable in 1866. And Andrea finds out about silver's anti-bacterial properties from Jean-Yves Maillard, Professor of Pharmaceutical Microbiology at Cardiff University.

For the Egyptians gold was the ultimate symbol of wealth, power and eternal life. For this reason they buried their Pharaohs with extraordinary amounts of gold artefacts. As a noble metal, gold doesn’t tarnish which added to its status and association with the sun god Ra and the afterlife. Andrea talks to Professor Marcos Martinon-Torres of Cambridge University at an exhibition of Tutankhamun’s riches, and to Professor Lynne Macaskie of Birmingham University about ways to recycle gold from our electronic waste using bacteria. The method offers a greener way to satisfy our lust for gold.

Picture: Gold and silver bracelets, Credit: krfletch/Getty Images

Next Episode

The Evidence: Covid 19: Sub-Saharan Africa and Testing

Claudia Hammond and a panel of international experts look at the latest research into Covid-19, the disease caused by the new coronavirus which is sweeping through the world. As the disease spreads how is sub-Saharan Africa handling the pandemic? We also look at tests – how accurate are they? Should we be testing ourselves at home? On the panel are Folasade Ogunsola, Professor of Clinical Microbiology at the University of Lagos in Nigeria, Ravi Gupta, Professor of Microbiology at the University of Cambridge’s Department of Medicine, Matthew Fox, Professor of Epidemiology and Public Health at Boston University and Dr Margaret Harris, a Spokesperson at the World Health Organisation.

The Evidence is produced in association with Wellcome Collection. Producers: Geraldine Fitzgerald and Caroline Steel Editor: Deborah Cohen