-Caveat Lector- <A HREF="http://www.ctrl.org/"> </A> -Cui Bono?- http://www.sci-ctr.edu.sg/ScienceNet/cat_life/cat_pha01778.html Recent Questions I micro-waved one cup of plain water for one minute at 100 degrees Celsius. After taking it out of the micro-wave oven, I put one tea spoon of instant coffee powder into the cup. Surprisingly, the water splashed out of the cup to a height of around 4 cm and scalded my hand. Is there any substance in the instant coffee powder that leads to such a 'reaction'? It happened only once. I have tried doing so many times but none has such an effect. Answer : A portion of the water in your cup was actually heated slightly above the boiling point. In other words, the water was becoming superheated. It would normally boil at this temperature. But, because of the smooth surface of the cup, the boiling is hindered by the lack of nucleation sites needed to form the bubble. Superheated liquid can boil explosively if something is added. The addition of some instant coffee powder sufficed to allow bubble formation. After keeping the cup still and micro-waving for a long time, turbulence in the superheated liquid by stirring or by moving the cup could also provide enhanced nucleation with an explosive rate of steam production. It could cause the liquid to splash out of the cup. This can be avoided by leaving any liquid that has been heated in a microwave oven to stand for at least a minute before touching it or open the door of the oven. This allows for slight cooling and for the heat to become more evenly distributed. It is therefore recommended that everyone does this when heating liquids in a microwave oven, even to make a cup of tea. <A HREF="http://www.ctrl.org/">www.ctrl.org</A> DECLARATION & DISCLAIMER ========== CTRL is a discussion & informational exchange list. Proselytizing propagandic screeds are not allowed. Substance—not soap-boxing! These are sordid matters and 'conspiracy theory'—with its many half-truths, misdirections and outright frauds—is used politically by different groups with major and minor effects spread throughout the spectrum of time and thought. That being said, CTRL gives no endorsement to the validity of posts, and always suggests to readers; be wary of what you read. CTRL gives no credence to Holocaust denial and nazi's need not apply. Let us please be civil and as always, Caveat Lector. ======================================================================== Archives Available at: http://home.ease.lsoft.com/archives/CTRL.html http:[EMAIL PROTECTED]/ ======================================================================== To subscribe to Conspiracy Theory Research List[CTRL] send email: SUBSCRIBE CTRL [to:] [EMAIL PROTECTED] To UNsubscribe to Conspiracy Theory Research List[CTRL] send email: SIGNOFF CTRL [to:] [EMAIL PROTECTED] Om
