Uploaded August 2026 | Updated September 2026, 3 weeks ago
Is the ocean really silent? And is the musical scale we grew up with dictated by physics, or is it something we just got used to? This Royal Institution talk explores the physics of sound and the physics of music through two connected investigations: underwater acoustics with oceanographer Helen Czerski, and musical tuning with science writer Philip Ball.
Helen Czerski busts the myth of "the silent world," explains how whale song travels thousands of kilometres through the ocean's hidden SOFAR channel, and revisits Walter Munk's extraordinary 1990s experiment to send sound across an entire ocean. She also shares fieldwork from Botswana's Chobe River investigating a genuine open question in ocean sound research: do hippos echolocate? The hippo sonar evidence from a very unusual carrot-hunting experiment is still debated.
Philip Ball tackles a musical scale explained from first principles: is it mathematically inevitable, or a cultural invention? He traces the story from Pythagorean tuning and just intonation through to equal temperament, unpacks consonance and dissonance, and explains how a "wrong" interval earned the nickname the tritone devil's interval; asking, ultimately, is music mathematical, or just convention?
Filmed at the Royal Institution, London, on 29 June 2026, in association with the docuseries For the Record: An Incomplete History of Music.
Due to copyright reasons, some music has been muted in this video.
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Watch the Q&A with Helen and Phillip here: youtu.be/7ljyOT62stU
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Helen Czerski is a former Christmas Lecturer, physicist and oceanographer with a passion for investigating the interesting things in life. She's a Professor in the Department of Mechanical Engineering at UCL, where she studies the physics of breaking waves and bubbles at the ocean surface. A regular BBC science presenter for a decade, she's covered the natural world in BBC2 landmark documentaries and everyday science in BBC4 documentaries, is a regular Horizon contributor, and presented BBC's Ocean Autopsy, examining human impact on the ocean.
Philip Ball is a freelance writer and broadcaster who was an editor at Nature for more than twenty years. He writes widely on the interactions between science, art and culture, and is the author of books including The Music Instinct, H2O: A Biography of Water, Bright Earth: The Invention of Colour, and Curiosity: How Science Became Interested in Everything. His book Critical Mass won the 2005 Aventis Prize for Science Books. He presents Science Stories on BBC Radio 4, trained as a chemist at Oxford and a physicist at Bristol, and is also the author of The Modern Myths.
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Chapters:
00:00 – Introduction: Helen Czerski's journey into ocean science
01:42 – Jacques Cousteau and the myth of "The Silent World"
05:21 – Whale song: how sound travels underwater
06:37 – Why sound bends and speeds up in the ocean
08:46 – Walter Munk's experiment to send sound across an entire ocean
16:22 – Fieldwork on Botswana's Chobe River
22:01 – Do hippos use echolocation? The carrot experiment
29:21 – Philip Ball: what actually makes a musical note?
33:52 – Why music is built around the octave
40:34 – Pythagoras and the mathematics of the scale
43:39 – Equal temperament: tuning a scale that works in every key
50:12 – Consonance, dissonance, and the "devil's interval"
55:57 – The tritone in Black Sabbath — physics or convention?
________________________
The Ri is on Facebook: facebook.com/royalinstitution
and TikTok: tiktok.com/@ri_science
Listen to the Ri podcast: podcasters.spotify.com/pod/show/ri-science-podcast
Donate to the RI and help us bring you more lectures: rigb.org/support-us/donate-ri
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Is the ocean really silent? And is the musical scale we grew up with dictated by physics, or is it something we just got used to? This Royal Institution talk explores the physics of sound and the physics of music through two connected investigations: underwater acoustics with oceanographer Helen Czerski, and musical tuning with science writer Philip Ball.
Helen Czerski busts the myth of "the silent world," explains how whale song travels thousands of kilometres through the ocean's hidden SOFAR channel, and revisits Walter Munk's extraordinary 1990s experiment to send sound across an entire ocean. She also shares fieldwork from Botswana's Chobe River investigating a genuine open question in ocean sound research: do hippos echolocate? The hippo sonar evidence from a very unusual carrot-hunting experiment is still debated.
Philip Ball tackles a musical scale explained from first principles: is it mathematically inevitable, or a cultural invention? He traces the story from Pythagorean tuning and just intonation through to equal temperament, unpacks consonance and dissonance, and explains how a "wrong" interval earned the nickname the tritone devil's interval; asking, ultimately, is music mathematical, or just convention?
Filmed at the Royal Institution, London, on 29 June 2026, in association with the docuseries For the Record: An Incomplete History of Music.
Due to copyright reasons, some music has been muted in this video.
___________________
Become a channel member to support our science content, and get exclusive access to Q&A sessions:youtube.com/channel/UCYeF244yNGuFefuFKqxIAXw/join
Watch the Q&A with Helen and Phillip here: youtu.be/7ljyOT62stU
Subscribe for regular science videos: bit.ly/RiSubscRibe
____________________
Helen Czerski is a former Christmas Lecturer, physicist and oceanographer with a passion for investigating the interesting things in life. She's a Professor in the Department of Mechanical Engineering at UCL, where she studies the physics of breaking waves and bubbles at the ocean surface. A regular BBC science presenter for a decade, she's covered the natural world in BBC2 landmark documentaries and everyday science in BBC4 documentaries, is a regular Horizon contributor, and presented BBC's Ocean Autopsy, examining human impact on the ocean.
Philip Ball is a freelance writer and broadcaster who was an editor at Nature for more than twenty years. He writes widely on the interactions between science, art and culture, and is the author of books including The Music Instinct, H2O: A Biography of Water, Bright Earth: The Invention of Colour, and Curiosity: How Science Became Interested in Everything. His book Critical Mass won the 2005 Aventis Prize for Science Books. He presents Science Stories on BBC Radio 4, trained as a chemist at Oxford and a physicist at Bristol, and is also the author of The Modern Myths.
__________________
Chapters:
00:00 – Introduction: Helen Czerski's journey into ocean science
01:42 – Jacques Cousteau and the myth of "The Silent World"
05:21 – Whale song: how sound travels underwater
06:37 – Why sound bends and speeds up in the ocean
08:46 – Walter Munk's experiment to send sound across an entire ocean
16:22 – Fieldwork on Botswana's Chobe River
22:01 – Do hippos use echolocation? The carrot experiment
29:21 – Philip Ball: what actually makes a musical note?
33:52 – Why music is built around the octave
40:34 – Pythagoras and the mathematics of the scale
43:39 – Equal temperament: tuning a scale that works in every key
50:12 – Consonance, dissonance, and the "devil's interval"
55:57 – The tritone in Black Sabbath — physics or convention?
________________________
The Ri is on Facebook: facebook.com/royalinstitution
and TikTok: tiktok.com/@ri_science
Listen to the Ri podcast: podcasters.spotify.com/pod/show/ri-science-podcast
Donate to the RI and help us bring you more lectures: rigb.org/support-us/donate-ri
Our editorial policy: rigb.org/editing-ri-talks-and-moderating-comments
Subscribe for the latest science videos: bit.ly/RiNewsletter
Product links on this page may be affiliate links which means it won't cost you any extra but we may earn a small commission if you decide to purchase through the link.
