Microwave sink (was: Re: strange remark about your collection?)

On 28 September 2012 20:17, David Riley <fraveydank at gmail.com> wrote: I have often boiled water in the microwave; when I had a Norwegian fianc?e, she did not own a kettle & always boiled water in the microwave. (Electricity is *very* cheap there, as they have lots of hydroelectric plants.) The thing is, normally, the water just boils. Almost any ordinary container has multiple nucleation points. Pour a fizzy drink into any household object; every chain of bubbles rising In the case of water in a mug or something, it can get to a good few degrees over 100?C (sorry, I cannot fathom Fahrenheit & have no clue what boiling point is in it; I use SI units, like all sensible people) and thus when you drop in a teabag or a spoonful of coffee, *FOOM*, instant boiling and water all over the counter-top. But getting hot enough to become superheated? That I have /never/ seen, even when someone set the timer wrong and the container boiled dry. Now, if it was a /sealed/ container, a reasonably strong one, able to withstand a lot of pressure before it blew - OK. But an open vessel? No, I don't believe it. Even scrupulously clean laboratory glassware has lots of nucleation points; getting water to supercool or superheat without crystallising or boiling is actually quite hard to do. Supercooling is easier but still nontrivial; it can happen by accident, but rarely. Either way, the further the temperature goes past the normal phase-change temperature, the smaller the imperfection needed to start the transition. -- Liam Proven ? Profile: http://lproven.livejournal.com/profile Email: lproven at cix.co.uk ? GMail/G+/Twitter/Flickr/Facebook: lproven MSN: lproven at hotmail.com ? Skype/AIM/Yahoo/LinkedIn: liamproven Tel: +44 20-8685-0498 ? Cell: +44 7939-087884