glass bang

[mr. piper]

• what causes glass when smashed, to go bang and then tinkle?(it really does)
• why can't a helicopter hover at high altitudes?
• 25% of human beings ever to have lived have died of what? 

[Ray The Grey]

1/ The crystal lattice structure of glass is very strong and requires a great deal of energy to break the bonds. The sound you hear is the energy you waste in breaking the glass released as sound - this is the bang. The tinkle is related to the harmonic properties of glass and their resonance when they strike an object - but not normally hard enough to break them significantly. It is mostly to do with realising some of the potential energy within glass.

2/ At lower altitudes helicopters can use fairly constant ground or ground based air currents to help maintain their uplift and maintain a steady position (ideally the ground itself). At higher altitudes this is not possible and so it is necessary to keep adjusting position, also wind speeds are faster the higher you travel, due to a differential in air pressure, density and friction due to the earth (and gravity) so they find it almost impossible to balance all these factors and hover.

3/ Possibly malaria - I think I read this somewhere ? All dead humans have died of brain death - either insufficient oxygen to the brain or too much (ie an axe crushing the skull) - brain trauma.

[mr. piper]

ray the grey, what can i say?

thankyou for bothering, i came up with the same conc myself, but at a seminar at U.C.L.A. it was pointed out that the crack in the glass travels at mach 1+ creating a resonance of such magnitude to produce the bang???

bang on with the chopper 

    the malaria thing is correct as unlikely as it seems aparently?