Re: Lava Lamp Left on Stove Explodes, Kills Man

TKM wrote...
> Once the liquid starts boiling, steam pressure would build quickly, of
> course.  The cap is threaded on the Lava Lamps that I've seen so the
force
> to remove the cap would be higher than if the cap were just pressed on.
> Some years ago, a glass gallon jug with a metal screw cap and a couple
of
> inches of cider was left in my garage for a week while I was away.  I
> returned to find the garage a mess with large glass shards everywhere. 
Some
> traveled 20 feet.  Good thing cider now comes in plastic jugs.

The Krakatoa explosion was due to steam pressure! - OK it WAS supposed to
be steam from about a cubic mile of seawater but even the instantanous
eva****ation of one cubic centimetre makes one hell of a bang!  The big
problem is that the boiling point of water increases under pressure so
whilst confined it will happily stay as a liquid.  When the containment
vessel fails then the water suddenly becomes hugely superheated and can
all
eva****ate almost instantanously (if the vessel had held a very high
pressure before failure) producing an enormous volume of steam and leading
to a seriously powerful explosion.  

The force of the explosion will be much greater if there is a significant
air-space in the vessel since, if totally full it will be cracked by the
expansion of the liquid water long before significant superheating can
occur.  

David