Skip to content

Sound Waves: The Symphony of Physics

Featuring: Video Video

Dr Helen Czerski takes us on a sonic odyssey through the sounds of the universe – to reveal what the physics of sound can tell us about the world and how it works

Share on Google Plus Share on LinkedIn View article Comments

The world is awash with sound waves, they are all around us. However sound is so much more than simply a soundtrack to our lives, and the more we’ve discovered about the physics of sound, the more extraordinary the secrets it has revealed.

In this surprising and engrossing two part series Dr Helen Czerski will go on a spectacular journey into the world of sound to discover what it is, how it’s detected and what it can tell us about the world, and even the universe. From the top of one of Europe’s most active volcanoes to Big Ben, Helen will explore the limits of sound.

Helen also examines how the very nature of sound has helped us survive, communicate and explore our surroundings. From imaging the vocal cords of singer Lesley Garrett to tracing the development of sonar technology Helen probes the power of sound to communicate, revealing how sound has helped us see underwater, driven the evolution of extraordinary biological systems and helped us understand our planet.

Packed with spectacular imagery, jaw-dropping experiments and some of the most remarkable sounds you’ve ever heard, this is the ultimate guide to one of our universe’s most magical phenomena. 

The first episode of Sound Waves: The Symphony of Physics will be broadcast on BBC Four on Thursday 2nd March at 9pm. Full broadcast details, and watch again links, can be found on

Episode Guide

Making Sound

Helen Czerski stands in front of a large bell Copyrighted image Icon Copyright: The BBC In episode one, Helen Czerski begins by exploring the simplest of ideas: what is a sound? At the Palace of Westminster, Helen teams up with scientists from the University of Leicester to carry out state-of-the-art measurements using lasers to reveal how the most famous bell in the world – “Big Ben” – vibrates to create pressure waves in the air at particular frequencies. This is how Big Ben produces its distinct sound. It's the first time that these laser measurements have been done on Big Ben.

With soprano singer Lesley Garrett CBE, Helen explores the science of the singing voice – revealing in intimate detail its inner workings and how it produces sound. Lesley undergoes a laryngoscopy to show the vocal folds of her larynx. At University College London, Lesley sings “I Dreamed A Dream” inside an MRI scanner to reveal how her vocal tract acts as a “resonator”, amplifying and shaping the sound from her larynx.

Having explored the world of sounds with which we are familiar, Helen discovers the hidden world of sounds that lie beyond the range of human hearing. At the summit of Stromboli, one of Europe’s most active volcanoes, Helen and volcanologist Dr Jeffrey Johnson use a special microphone to record the extraordinary deep tone produced by the volcano as it explodes – a frequency far too low for the human ear to detect. Helen reveals how the volcano produces sound in a similar way to a musical instrument – with the volcano vent acting as a “sound resonator”.

Finally, at the University of Cambridge’s Institute of Astronomy, Helen meets a scientist who has discovered evidence of sound waves in Space, created by a giant black hole. These sounds are one million billion times lower than the limit of human hearing and could be the key in figuring out how Galaxy Clusters, the largest structures in the universe, grow.

Episodes in this series

Episode Description
Making Sound In this programme, Dr Helen Czerski investigates the extraordinary science behind the sounds we’re familiar with and... Read more
Using Sound In this programme Dr Helen Czerski examines the extraordinary messages sound wave carry, and how they help us... Read more