National Geographic News

Explaining the physics of the snapping



  1. Ken in Berkeley says:

    The whole thing seems a little fishy to me. I am especially skeptical of the comment, “As the bubbles collapse, they momentarily reach the temperature of the Sun.”

  2. hhopper says:

    Read the info. on the links I included. I’m a little less skeptical now.

  3. Angel H. Wong says:

    [violation of guidelines]

  4. Lauren the Ghoti says:

    Fascinating; I’m just intrigued about how they came up with that unreferenced 200dB figure. Measurement of SPL in water vs. gas are referenced to different pressures, for one thing – and SPL also must be stated in reference to distance from the source.

    Relative to human hearing, 200 deciBels is an absolutely astronomical figure at any distance… In fact, above 194dB, which equates to 1 atmosphere, they’re no longer sound waves, they’re shockwaves; at 195 it’s the sound of a ton of TNT going off 60 feet away. Around 200dB is 1 on the Richter scale(!)

    So I’m a just a wee bit skeptical about that number…

  5. edwinrogers says:

    What a pretty little shrimp.

  6. BubbaRay says:

    #4, Lauren, they must be measuring the SPL right at the tip of the claw, since dB measurement is affected by the inverse square law. 200 db? Cheese, the threshold of pain for the human ear is what, about 130 dB? Standing next to an F16 in afterburner you get maybe 140 dB. You are correct, 200 dB is unimaginable, about 10^8 Watts / Meter^2. Maybe that temp is believable, considering the power.

  7. I found this story fascinating! I appriciate the added links to help back up the article, even though temperature part still seems rather extreme to me (maybe the temperatue is reached for just 10 nanoseconds as suggested allows for such an extreme) . The rest of the story seems quite credible and is an interesting way for a tiny creature to gets it’s meal.

  8. ECA says:

    I think that most of this has to deal with RANGE.
    The dispertion of sound at distance is VERY large…
    and if you watch the video, you notice the shrimp gets Fairly close.
    This is like CLAPPING next to someones EAR.

  9. JoaoPT says:

    Well the medium is water, not air…
    the rest I just don’t know, and frankly who cares. The fact is that it works, and that’s all that shrimps cares.

  10. Anonymous Coward says:

    It was a fish fart!

  11. Jon says:

    truly amazing what blind naturalistic processes can come up with, eh?

  12. sdf says:

    There’s no way this was evolution
    http://youtube.com/watch?v=t7I73DNguRI

  13. B. Dog says:

    Kinda strange isn’t it? Nobody has commented on the secondary flashes and the implications regarding cold fusion. The possibility that crustaceans are using tiny nukes is being hushed up, eh?

  14. hhopper says:

    #13 – Funny you should mention that. That’s the first thing I thought of…cold fusion. Although 8540° F is not particularly cold. I don’t really understand the physics of it.

  15. BubbaRay says:

    #14, Hop, nothing near fusion, it’s all about the collapse of the cavitation bubble created by the claw. Reference:

    http://www.sciencemag.org/cgi/content/abstract/289/5487/2114

  16. JoaoPT says:

    Cold fusion… Há!