[HN Gopher] Lithophone
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       Lithophone
        
       Author : polm23
       Score  : 33 points
       Date   : 2020-02-22 05:20 UTC (17 hours ago)
        
 (HTM) web link (en.wikipedia.org)
 (TXT) w3m dump (en.wikipedia.org)
        
       | crazygringo wrote:
       | Crazy -- rocks that resonate and sound like metal!
       | 
       | Unfortunately that article gives zero explanation of how certain
       | rocks can produce resonant tones that sound like metal, but
       | another one does, specifically that the rocks need to be under
       | internal stresses, analogous to a tightened guitar string: [1]
       | 
       | "...it does suggest strongly that the ringing ability is a direct
       | result of internal stresses. ... A possible source of the
       | stresses would likely be the loading stresses from the time when
       | the rock crystallized. ... This "relict stress" theory implies
       | that the ringing rock boulders act much like a guitar string.
       | When a guitar string is limp it does not resonate, but a plucked
       | string will provide a range of sounds depending on the level of
       | applied tension. Likewise, a ringing rock boulder will only emit
       | a dull thud if the boulder is de-stressed; however, boulders will
       | resonate at various frequencies depending on the level of
       | residual stress."
       | 
       | [1] https://en.wikipedia.org/wiki/Ringing_rocks#Ringing_ability
        
       | bergoid wrote:
       | The granite sarcophagus in the "Kings's Chamber" [1] of the Great
       | Pyramid of Giza has been used as a lithophone too. Paul Horn's
       | record album "Inside The Great Pyramid" [2] starts with the sound
       | of the sarcophagus being rung like a bell.
       | 
       | [1]
       | https://en.wikipedia.org/wiki/Great_Pyramid_of_Giza#King's_C...
       | 
       | [2]
       | https://www.youtube.com/watch?v=2ZmyGavbgLE&list=PLPtysUSalP...
        
       | James_Henry wrote:
       | I would advise watching some of the videos linked near the bottom
       | of the article and then watching some of the others on youtube.
       | Rocks can make beautiful noise
        
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       (page generated 2020-02-22 23:00 UTC)