Re: How to explain this?

[Mark Lucas <lucas@LUCAS.PHY.OHIOU.EDU>]

This is an issue of superheating.

A google search on "superheated boiling" brought up the second link as:

http://newton.dep.anl.gov/askasci/chem00/chem00636.htm

They've got much better explanations than I could give.

Mark

On Tue, 18 Feb 2003, Ludwik Kowalski wrote:

> This morning I observed something unusual. A common cup
> filled up to about 80% with milk, and with about 1/2 spoon of
> dissolved coffee, was placed into a microwave oven. I opened
> the microwave door at the moment the milk started rising. Then
> I removed the cup and placed it on the table. I was glad that
> nothing was spilled. Nothing unusual so far.
>
> About ten seconds later I took a spoon (at room temperature)
> and immersed it into the cup. That resulted in a sudden rise of
> foam with milk and some of my coffee was spilled. How can this
> be explained? Why did placing a cold spoon into the hot coffee-
> milk produce a sudden boiling-like =93explosion?=94 I have never
> seen anything like this.
> Ludwik Kowalski

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Mark Lucas                                      email: lucasm@ohiou.edu
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