Re: what exactley happens when a person snaps their fingers togeather

Hi,
While I'm not a biophysicist, I'll give you a simple answer.  Pressing your 
finger and thumb together firmly, then sliding them apart does generate 
friction, but the snapping sound comes from the rapid contact between 
finger and base of thumb.  The sound resonates through the base of your 
hand to some extent and depending upon the density of the soft tissue will 
alter the frequency.  And, just in case you were wondering, the sound which 
occurs when someone pops their knuckles occurs because the slight 
separation of joints causes the rapid formation of small air bubbles in the 
synovial fluid in the capsule surrounding the articulation, which generate 
the popping sound.  I hope this helps.
Karl J. Roberts, Ph.D.