Super heating water in a microwave oven

[rollcast]

Is this caused by a lack of nucleation for the gas pockets to be formed or the uneven heating of the water?

A clean cup isn't proviingvery many nucleation sites and is it this combined with the even heating meanings the chance of the super heated molecules reaching these sites is reduced is the cause

 

[pallidin]

Here's a good site on the subject:

http://www.snopes.com/science/microwave.asp

 

[Isaacsname]

Is this caused by a lack of nucleation for the gas pockets to be formed or the uneven heating of the water?

A clean cup isn't proviingvery many nucleation sites and is it this combined with the even heating meanings the chance of the super heated molecules reaching these sites is reduced is the cause

Yes, a lack of bubble nucleation sites.

The reason fluids get superheated isn't just a lack of sites for nucleation, it also happens when you leave something in the microwave and reheat it, forget it, reheat it, rinse and repeat. This effectively degasses the fluid to some varying degrees, or at least, that's how I understand it.

Be careful.