Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] pistol shrimp



Hi All,

Cavitation does occur in this shrimp claw. It was once believed that the sound came from physical contact between claws. Not so.

Here is a wonderful video from the original researchers (or spoofers!) explaining the phenomena of snapping (aka pistol) shrimp. Fortunately, the world is often stranger than we imagine. I have had fun chasing my son around pretending be a snapper.

http://ecommons.library.cornell.edu/handle/1813/9379

Title: On the sound of snapping shrimp
Authors: Versluis, Michel
Schmitz, Barbara
von der Heydt, Anna
Lohse, Detlef

Keywords: Fluid dynamics video
cavitation
snapping shrimp
bubble collapse

Issue Date: 13-Dec-2007

Series/Report no.: Gallery of Fluid Motion
2001-1

Abstract: Snapping shrimp produce a snapping sound by an extremely rapid closure of their snapper claw. Our high speed imaging of the claw closure has revealed that the sound is generated by the collapse of a cavitation bubble formed in a fast flowing water jet forced out from the claws during claw closure. The produced sound originates from the cavitation collapse of the bubble. A model based on the Rayleigh-Plesset equation can quantitatively account for the visual and acoustical observations.

Description: see Versluis, Schmitz, von der Heydt, Lohse, Science 289, 2114 (2000); Phys. Fluids 13, Number 9, S13 (2001).

URI: http://hdl.handle.net/1813/9379

Appears in Collections: Fluid Dynamics Videos

Best Wishes,
--
Jeff Radtke
jr@cloudchambers.com
www.cloudchambers.com


Quoting Richard Grandy <rgrandy@rice.edu>:

I may well be wrong, and I am not a physicist. But I would like to
hear from some of the physics people on the list about what happens
if you have an undersea region at 20,000K. And then multiply that by
lots of these pistol shrimp killing prey day by day. I think someone
would have noticed.

Or maybe someone can explain the thermodynamics of these little
shrimp producing 20,000K temperatures in a non-negligible region.

My money is 100-1 spoof.


REG



Sonoluminescence--Wikipedia
"More than 50 years later, in 1989, a major advancement in research
was introduced by Felipe Gaitan and Lawrence Crum, who were able to
produce stable single-bubble sonoluminescence (SBSL). In SBSL, a
single bubble, trapped in an acoustic standing wave, emits a pulse of
light with each compression of the bubble within the standing wave.
This technique allowed a more systematic study of the phenomenon,
because it isolated the complex effects into one stable, predictable
bubble. It was realized that the temperature inside the bubble was
hot enough to melt steel. Interest in sonoluminescence was renewed
when an inner temperature of such a bubble well above one million
Kelvins was postulated. This temperature is thus far not conclusively
proven, though recent experiments conducted by the University of
Illinois at Urbana-Champaign indicate temperatures around 20,000
Kelvins."

Surface temperature of sun approx 6000 K

If it is sonluminexcence the claim is not a spoof.

VL

On Dec 3, 2008, at 10:58 PM, Richard Grandy wrote:

You didn't listen closely enough, the clip says that the shrimp
produces temperatures equal to that of the sun! I think the
technical name for the mechanism is "spoofing".

A student send me this video clip. Scroll down to "Play Video"
It's of a
shrimp that produces a sound so loud it produces light -- and a water
temperature of several thousand degrees! Amazing! How is this
possible?

http://community.atom.com/Post/The-Most-Disturbing-Animals-on-
Earth/03EFBFFFF0182C7B8000800A5BDC5/


_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l