OT Does a microwave oven kill airborne germs?

Actually 1997 UNWISE MICROWAVE EXPERIMENTS guy.

The metal walls are nodes for e-field waves.

The "hot spot" antinodes are a quarter-wave away from the metal, 31mm away for 2.45GHz ovens in usa. Things won't cook if near the metal; they need to be lifted 1-1/4" off the conductive floor. And besides, the metal serve s as a large heatsink and stays fairly cold (except when the oven is empty, and in that case the metal acts as a significant absorber for the huge sta nding wave. Even the glass disk gets heated when the oven chamber is other wise unloaded.)

Essentially the metal surfaces are shorting out the e-field. The e-field c omponent provides the dielectric heating effect.

If EM is a plucked guitar-string, then the screws at the ends of the string are the cold spots, and the big vibrate-y parts in the middle have the max imum heating effect.

I haven't tried melting out the bottoms of cheap storage bowls using oil. Bet it works! Do up some microwave fried food, seasoned with boiling liqu id plastic. Mmmmm, polyethelene-y! In normal situation the bottom of the bowl ususally has some wet food, so it can't heat very far above 100C. T he upper edge gets the no-water oil-splatters.

Not me. But I'm not a Marx / redistribution guy--that's too cynical--so that limits the choices presently.

In my Birkenstocks, no less. But mostly no, they're way over-priced.

Ye Olde Supermarket.

I've done that too. I've eaten in many a far corner (not to mention wilderness) of this world, and you have to learn to be flexible.

Cheers, James Arthur

P.S. I voted for Carter. (Yes, I was that foolish, that uneducated, once.)

Nope, that's a very widespread misconception; another infectious physics-me me spread everywhere and nearly impossible to stamp out. Water is heated by broadband dielectric losses, not by narrowband resonant absorption. Th is is done intentionally. If we used 50GHz magnetrons, then all the watta ge would be absorbed by a thin outer layer of food, and we'd end up with co nventional cooking behavior. By operating far out on the absorption tail, RF penetrates deep into water, giving the "cooks inside" effect.

The strong resonant absorption for water is up around 20GHz, and rising muc h higher at boiling temperature. And it's not a narrow resonance (need ga s molecules for that, not bulk liquid.)

Don't forget that diathermy at 13.6MHz 27.1MHz etc. works just fine on wate r.

Main ref page is down, but here's Wayback:

The problem is that most never learn from their mistakes (so did I, twice).

None of this changes the fact that the energy is absorbed directly by the molecules. It does not require any particular size of the water droplet or capacitor plates.

On Fri, 25 Dec 2015 11:31:39 -0500, rickman Gave us:

Nope. The molecules heat because they are forced back and forth.

It is called hysteresis. They are not "absorbing energy". They are exhibiting heat from the friction during the hysteresis. It (microwave) is a form of induction heating.

Probably best if a tunneling device...lots of experience in the ant community.

s-meme spread everywhere and nearly impossible to stamp out. Water is hea ted by broadband dielectric losses, not by narrowband resonant absorption. This is done intentionally. If we used 50GHz magnetrons, then all the w attage would be absorbed by a thin outer layer of food, and we'd end up wit h conventional cooking behavior. By operating far out on the absorption ta il, RF penetrates deep into water, giving the "cooks inside" effect.

much higher at boiling temperature. And it's not a narrow resonance (nee d gas molecules for that, not bulk liquid.)

water.

Yep, just need high volts AC, dipole molecules, and bonds between them.

The EM field torques the molecules, injecting energy to break those intermo lecular bonds which keep water liquid. EM energy gets absorbed and turned into bond vibrations (phonons: heat.)

What aspect of the molecules toggle? The description I read talked about hydrogen bonds.

"Forced back and forth"? You mean they are moved? Can you explain how that happens? They have no net charge. They have a dipole moment which would cause a potential rotation to align with a magnetic field.

Do you have any references? I haven't found any references that claim anything like this.

That matches what I read.

Which psych ward is this posting from?

On Sat, 26 Dec 2015 02:19:37 -0500, rickman Gave us:

The same way a ferrous medium gets "oriented" in a magnetic field.

It is not just water that is able to be heated.

I have used it for oil, alcohol, brominated solvents, fluorocarbon dielectric fluids, etc.

The key is that certain liquids are able to be flipped back and forth and the flipping exhibits heat.

On Sat, 26 Dec 2015 02:22:00 -0500, rickman Gave us:

Ding!

The microwave IS exhibiting a magnetic field into the cavity and DOES orient them *really fast*.

That exhibits heat as they have hysteresis and are thus being *forced* into said orientations.