Sonoluminescence: Creating Light From Sound

Nature is full of wonders, sometimes what you see is unbelievable and the other time, what you believe may not be part of nature.  Sonoluminescence is one such counter intuitive phenomenon, which is very rare and took scientists off guard. What more, this phenomenon is demonstrated by a tiny critter in the ocean, Mantis Shrimp.

What is Sonoluminescence?

Sono means sound, while lumen means light. The word literally means creation of light from sound, which may sound impossible , as it was to me in the beginning but there is scientific explanation to it. Technically, it is a pulse of light, which is generated when a bubble collapse over itself. This bubble is generated by the sudden outburst of sound. It is basically a conversion of acoustical or sound energy into light energy which is part of nucleation, growth and collapse of bubbles in liquid.

2) Behind the scene

There is more to it, the bubble generated during this process makes the surrounding water hotter than the surface of the sun or around 10000 kelvins in the interior of the bubble. This is enough to ionize the noble gas around it. Which is unbelievable, and to think of a small sea living creature can do it is even more astounding. However, this sudden rise in temperature quickly cools down, in fraction of a second or less than 100 picoseconds approximately, before it has any impact other than unsuspecting pray of this shrimp, which gets stunned by this unworldly attack. This process said to produce around half million photons.

 

3) History

The discovery of Sonoluminescence is dated back to 1934, when H. Frenzel and H. Schultes at the University of Cologne, first observed it in an ultrasonic water bath. This was the result of very strong ultrasonic fields generates flashing bubbles now known as "multi luminescence". It was not until 1988 when D. Felipe Gaitan was able to successfully generate an isolated bubble for study.

4) How Mantis Shrimp does it?

So, how mantis shrimps can achieve such a complex mechanism. Mantis shrimps are cousins of crabs and lobsters. They have very specially evolved hinged arm under the head, folded. The Mantis shrimp has an ability to unfold or unfurl these hind arms at a blinding speed. causing bubble to move at the speed of around 100kmph. This sudden change cause release of sound of around 218 decibels. To think of gunshot only generate 140 decibels of sound. Sound more than 200 decibels can even kill a human.  It is so fast that it generates a force of a bullet and a pressure of around 80 kPa at 4 cm from the claw. This movements cause low pressure in front of arm causing water to boil and form a small bubble. The bubble collapse as soon as outward pressure gives in to inward pressure of surrounding water. The process is so quick that expansion of bubble happens in micro seconds while the emission takes Pico seconds. This process is called cavitation and the amount of energy released can punch dent in the metal not to speak of what it can do to sea creatures.

Reading all about this, I am still not able to wrap my head around it. A simple looking sea creature generates so much force which is faster than a vehicle, force stronger than a bullet impact, sound loud enough to kill and temperature greater than sun's surface, plus all this combined generates light as well. I don’t want to be anywhere near to mantis shrimp when it is performing this stunt and that’s for sure.

Footnotes

----------------------------------------------------------------------------

My Other Links

----------------------------------------------------------------------------

Articles List : https://azblogs4u.blogspot.in/p/articles-list.html

Youtube Channel : Learnitium - https://www.youtube.com/channel/UChlqyi2M5ywy85FSHI0i-tg

----------------------------------------------------------------------------

Credits -

References -

Sonoluminescence: https://en.wikipedia.org/wiki/Sonoluminescence

Focus: Size Matters for Flashing Bubbles: https://physics.aps.org/story/v7/st23

 Sonoluminescence, Applications Featured at SCCM Meeting: https://www.aps.org/publications/apsnews/199511/sccm.cfm

SONOLUMINESCENCE: SOUND INTO LIGHT: https://acoustics-research.physics.ucla.edu/sonoluminescence/

Sonoluminescence Is Light Made From Sound: https://curiosity.com/topics/sonoluminescence-is-light-made-from-sound-curiosity/

SL100B A Ready to Run Complete Sonoluminescence System: http://www.sonoluminescence.com/

Sonoluminescence : http://techmind.org/sl/

SONOLUMINESCENCE: https://hackaday.com/2010/06/28/sonoluminescence/

The mantis shrimp – the world’s fastest punch: https://notexactlyrocketscience.wordpress.com/2006/08/28/mantis-shrimps-the-worlds-fastest-punch/

Images - Pixabay, Wikimedia