Not true about "people" heating in glass. My grandmother had a glass(pyrex I
assume) coffee pot that you would heat on the stove top directly. I
remember from a childhood, early 70's and it looked old then. It had a
insert for the percolation and you could watch the coffee spit at the top of
the lid. I was fascinated as a child. Completely forgot about it till the
comment below.
Amazing what is hidden inside the old head.
dave
-----Original Message-----
From: Bernard G. Cleyet & Nancy Ann Seese
[mailto:georgeann@REDSHIFT.COM]
Sent: Thursday, February 03, 2000 4:00 PM
To: PHYS-L@lists.nau.edu
Subject: Re: Hot water in microwave
I think I have the answer: Until the microwave oven, it was unusual for
"people" to heat liquids in glass. The usual utensils have nucleating
sources which make it difficult to superheat. With the microwave most
don't use metal sauce pans in which to heat. This explains the sudden rash
of experience with superheated liquids. I suspect that putting any rough
solid, especially a powder (instant coffee), in a superheated liquid will
cause explosive vaporization.