Probes, sondes and sounds - Heinz Wolff's 1975 Christmas Lectures 4/6

From a channel Lumen includes in full: The Royal Institution, home of the Christmas Lectures, posts full public lectures and demonstrations by working scientists on physics, chemistry, biology, maths and technology, with the speakers' own audience Q&A sessions.

A 62-minute video from The Royal Institution's catalogue; the title names its topic.

Video by The Royal Institution, played through YouTube's embedded player.