note there was a * next to boiling water.
you might know, most manufacters warn about overheating water in a microwave oven.
when water is heated, it tends to 'move' and as it moves over small flaws in a finish (of a pot or cup) 'bubbles of steam' break out. (it moves on a molecular level, and watched, you can see eddies of movement!)
but if you microwave water in a super smooth vessel (a brand new glass beaker) it can super heat.. that is, it can reach 220 or 225 degrees (hotter than boiling) with no evidence! the smooth sides/bottom of the vessel doen't offer any places for the fast moving molocules to snag on, and 'burst into bubbles' (of steam)--so the steam stays trapped in the water, super heating it.
when you move the cup, you can slosh the super heated liquid,and break the surface tension.. then it can 'explode' --with a gush of steam, that releases the excess heat, and splashes the water.
so, its quite possible to heat water (under normal pressure) to a super hot liquid.. but normally (one good wash with a nylon scrubby) steam will start to expand and 'erupt' gently (in the form of bubbles) from water at 212 degrees F.
since mirco waves have become common, there have been more that several occations when super heated water has injured people.. (i don't really know if that is ergodic example or not.. but boiling water isn't as 'predictable' as you might think!)
