In our defence (spelt correctly) all of the above are acceptable, except the microwave. Reasons being that a) the microwave doesn’t boil it evenly, and you get pockets of mega heated water that bubble up and splash up in the microwave, then drip off the manky ceiling of the microwave and into your cup. B) microwaves stink. I don’t know anyone that uses one for anything other than popcorn or melting butter. But if you’re using it to cook as well… 🤢
Convection currents don’t stir water in a microwave because the heat source isn’t on the bottom. That’s the difference. You get temperature stratified water where the surface is hotter than the bottom of the cup and they don’t naturally mix.
Of course, here in America, we have this incredible technology called a spoon. Pull that bad boy out, give a little stir, problem solved.
Convection currents don’t need the heat source to be directly at the bottom to stir the liquid, it just needs cold water to be on-top of hot, because cold is more dense.
Microwaves don’t really heat top to bottom either, it’s shooting waves through the body of the water and even the cup, directly exciting a bunch of individual H2O atoms in hot spots where the microwaves peak at, (e.g. the actual microwaves not the name of the machine) heating the liquid very unevenly. The wave could very much be heating a fraction of the top, middle, and bottom at different points in 3d space. it just depends on the peak of the micro-waves.
I’m well aware of temperature stratification. It doesn’t happen in a microwave in the same way.
Micro waves don’t heat purely the top surface, they penetrate the entire waters body creating super-heated localized hotpots that shift the water around from Convection currents because the hotter more excited water atoms are less dense than the colder less excited water atoms above them spreading temperature out from those hotspots.
Temperature stratification only comes into play if there’s no nucleation point, in which you get this.
Also, your link is dead.
In our defence (spelt correctly) all of the above are acceptable, except the microwave. Reasons being that a) the microwave doesn’t boil it evenly, and you get pockets of mega heated water that bubble up and splash up in the microwave, then drip off the manky ceiling of the microwave and into your cup. B) microwaves stink. I don’t know anyone that uses one for anything other than popcorn or melting butter. But if you’re using it to cook as well… 🤢
Convection currents don’t stir water in a microwave because the heat source isn’t on the bottom. That’s the difference. You get temperature stratified water where the surface is hotter than the bottom of the cup and they don’t naturally mix.
Of course, here in America, we have this incredible technology called a spoon. Pull that bad boy out, give a little stir, problem solved.
Convection currents don’t need the heat source to be directly at the bottom to stir the liquid, it just needs cold water to be on-top of hot, because cold is more dense.
Microwaves don’t really heat top to bottom either, it’s shooting waves through the body of the water and even the cup, directly exciting a bunch of individual H2O atoms in hot spots where the microwaves peak at, (e.g. the actual microwaves not the name of the machine) heating the liquid very unevenly. The wave could very much be heating a fraction of the top, middle, and bottom at different points in 3d space. it just depends on the peak of the micro-waves.
I mean, it’s not really a matter of debate TBH. There are a number of peer reviewed journal articles documenting the temperature stratification. Here is one source, where the authors attempt to create a special cup to heat the water more evenly.
I’m well aware of temperature stratification. It doesn’t happen in a microwave in the same way.
Micro waves don’t heat purely the top surface, they penetrate the entire waters body creating super-heated localized hotpots that shift the water around from Convection currents because the hotter more excited water atoms are less dense than the colder less excited water atoms above them spreading temperature out from those hotspots.
Temperature stratification only comes into play if there’s no nucleation point, in which you get this.
Also, your link is dead.