The Nature of Things - Crystals and Gems
Crystal structureCrystal structure
The Cullinan DiamondThe Cullinan Diamond
Mohs scale of mineral hardnessMohs scale of mineral hardness
Refractive indexRefractive index
Tales from the Prep Room: DiffractionTales from the Prep Room: Diffraction
Tales from the Prep Room: Diffraction
About this video
Lawrence Bragg explores the Nature of Things.
'Crystals and Gems' is the last show in the first series recorded by the Beeb and explores the properties and molecular structure of crystals.
After demonstrating that the regular structure of crystals resemble "soldiers on parade or the pattern of a wallpaper", Bragg showcases a range of gemstones arranged according to the Mohs scale of mineral hardness such that the next stone up the scale will scrath the one before it.
Exploring the wondrous properties of diamonds he then explains how a extraordinarily high refractive index makes the gemstone sparkle so brilliantly before advising the "Ladies" of the audience to clean the back of their diamonds!
Bragg was, of course, a specialist in crystals having worked with his father William Henry Bragg to determine the molecular structure of crystals using their X-ray diffraction patterns in 1912-13; a discovery for which he received the Nobel Prize two years later.
Coates recalled Bragg once remarking to him: "never talk about science, show it to them", which is what The Nature of Things set out to do. Like the Christmas Lectures, the programmes were structured around a series of demonstrations and were filmed as a lecture in the Ri's theatre. Although the filming took place with an audience of adults, the series was aimed at children and broadcast on children's television. As he states at the end of the series, he hoped it would provoke "deep interest in the science of everyday things".
View more Nature of Things episodes in the Ri Archive Collection.
- Sir William Lawrence Bragg, William Coates
- London, UK
- Filmed in:
- The Theatre
The Royal Institution / BBC
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