3 ms·

I wonder how the speed of glass crack travel compares to the speed of sound in that particular kind of glass, and if the deficit can be accounted for by the fac

• nibbleshifter 4y ago
  The shockwave (which travels ahead of the cracks) travels at the speed of sound of the material. I'd hazard a guess the shockwave propagates about twice as fast as the cracks.
  • __MatrixMan__ 4y ago
    That's a fine guess, and it's not like I know any better, but if the fronts don't travel at the same speeds then... why? If there's enough kinetic energy to break the bonds in the material, what's it doing before they break?
    • AnotherGoodName 4y ago
      The cracks don't travel in a straight line the shockwave does. That's it. Speed of sound can be literally thought of as the speed that force propagates in a material.
      • xeonmc 4y ago
        > Speed of sound can be literally thought of as the speed that force propagates in a material. A.K.A. speed of mechanical causality
  • marcosdumay 4y ago
    The shockwave is probably at a constant distance from the cracks (AKA, the same speed). If it gets too far ahead, it will just create another crack, in an independent direction, and you get one of those random curves you get on the crack.