Posted By Tony Rodham
I wonder if anyone can help me please.
I am looking for a short video clip of the inherent dangers of heating liquids in a microwave oven.

I am aware that Microwaved water and other liquids do not always bubble when they reach the boiling point. They can actually get superheated and not bubble at all. The superheated liquid will bubble up out of the cup when it is moved or when something like a spoon or tea bag is put into it.

It is caused by a phenomenon known as super heating. It can occur anytime water is heated and will particularly occur if the vessel that the water is heated in is new, or when heating a small amount of water (less than half a cup).

What happens is that the water heats faster than the vapour bubbles can form. If the cup is very new then it is unlikely to have small surface scratches inside it that provide a place for the bubbles to form. As the bubbles cannot form and release some of the heat has built up, the liquid does not boil, and the liquid continues to heat up well past its boiling point...

What then usually happens is that the liquid is bumped or jarred, which is just enough of a shock to cause the bubbles to rapidly form and expel the hot liquid? The rapid formation of bubbles is also why a carbonated beverage spews when opened after having been shaken.

I am after a video clip that demonstrates this for educational purposes and any help would be greatly appreciated.

Thank you & kind regards to all

Tony

Posted By Karen Todd
I know of someone that this happened to - they were heating soup in the microwave on holiday and as they lifted the bowl out they said it just exploded and covered their hand in boiling soup, and a very nasty burn resulted.

KT

Posted By Jane Blunt
You can save the video to your computer. While it is running, hover over it with the mouse and 'right click'. this brings up a menu of options, one of which is to save the movie.

Jane