Field of Science

Tin tears

Tin cries. Not tears, but when tin is bent it elicits a peculiar sound called by metallurgists a "tin cry". Indium also lets out a scream when deformed, as Michael Cassidy pointed out in an earlier comment.

You are hearing the sound made by a phase transition, a change in the structure of the metal at the atomic level. Indium in its crystalline form is tetragonal, when bent, the mechanical stress induces "twinning" in which sections of the crystal become mirror images of adjacent planes. Twinning plays a role in mechanical failure of metals subject to stress, the research literature goes back roughly a century.


Listen to a recording of indium "screaming" made by Theodore Gray at the WGBH studios. It's an unnerving sound, more like a crackling than a scream.

The photo is courtesy of David Hammon in the physics department at the University of Vermont.

4 comments:

  1. Interesting post. I also wanted to let you know that I've gone through your entire Pchem lecture series to brush up on my QM. A full semester class condensed into 10 days! They were extremely helpful and I appreciate the time you took to post them. Cheers!

    ReplyDelete
  2. I really loved your blog. Chemistry is my actual passion. I'm studing Pharmacy at college.

    best regards!


    Br. :P

    ReplyDelete
  3. I didn't know about these elemental sounds at all and I did my chemistry degree in the 80s and have been writing about the subject almost since I graduated...of course the elements have their own unique sound in the amazing Tom Lehrer song - The Periodic Table. Dis-caaaarvard gets me every time...

    David Bradley Science Writer
    http://www.sciencebase.com

    ReplyDelete

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