28 Sep
2012
28 Sep
'12
11:32 a.m.
On 9/28/12 1:17 PM, David Riley wrote:
On Sep 28, 2012, at 1:55 PM, Mark Tapley wrote:
A common canning jar is smooth enough to superheat "soft" water.
Personal experience, trip to the opthamologist, etc...
Doc
At 12:00 -0500 9/28/12, Rob wrote:
I was always under the impression that that sort of story was an
urban legend. The physics isn't out of the question, I just can't
imagine any container in a household that wouldn't provide a
sufficiently rough surface to nucleate. Surprised to hear it's a
thing! Many years ago, I actually had a microwave
intermittently turn on
by itself... We (usually) took to leaving a jug of water in it
while quickly sourcing a replacement.
This may not be the best idea, unless your water is "dirty" (in the
sense of having something suspended that forms nucleation sites for
steam bubbles). Our water is "clean", and my wife once decided to
try to heat some up in our microwave. It superheated by a
noticeable amount, then finally boiled off catastrophically. Big
cloud of steam, microwave door blown open, loud noise, 100 C water
splashing around the kitchen. There was some damage apparent later
in the switch that should normally turn the thing off when the door
is open, which I eventually had to replace, but otherwise the
microwave itself was OK.