Timeline - Underwater acoustics
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Slide the time bar to see key dates relating to early discoveries about The Noisy Reef. Pause the mouse pointer over any of the boxes to see additional information about each event. Find out more about key developments in underwater acoustics by browsing or searching the hub.
Leonardo da Vinci writes the first reports of listening to sound under water. “If you cause your ship to stop and place the head of a long tube in the water and place the outer extremity to your ear, you will hear ships at a great distance from you.”
Sound and mathematics
Sir Isaac Newton first describes sound in mathematical terms.
Physicist Jean-Daniel Colladon and mathematician Jacques Charles François Sturm make the first measurements of the speed of sound under water.
German physician and physicist Hermann von Helmholtz designs the first Helmholtz resonator.
The birth of German physicist Heinrich Rudolf Hertz – a founder of the field of electromagnetic theory and namesake for the hertz unit.
Technology for listening for submarines under water is developed and deployed for the first time.
First scientific paper
The first scientific paper on underwater acoustics is published.
The transmission unit (TU) is renamed the ‘bel’ in honour of the founder of Bell Laboratories, Alexander Graham Bell.
Physics of sound
The book Physics of Sound in the Sea is published as a summary of advances in the field during World War II.
Americans Howard Vollum and Jack Murdock develop the triggered oscilloscope – the forerunner to the modern oscilloscope.
Underwater recording station
The New Zealand Navy places a permanent underwater recording station on Great Barrier Island in the Hauraki Gulf.
Hertz becomes standard unit
The General Conference on Weights and Measures adopts the hertz as the standard unit for measuring the frequency of sound, replacing cycles per second (CPS).
New Zealand scientists identify the ‘evening chorus’ and propose kina as the source of the increase in underwater reef sound at dusk.
Kina and noise
Researchers from the Leigh Marine Laboratory conclusively show the role of kina in the production of reef noise.
Crab larvae and noise
Researchers from the Leigh Marine Laboratory publish their studies on the settlement and metamorphosis of crab larvae in response to reef noise.
Image: Andy Heyward