What's the problem with Microwave Ovens?

[PeteB99]

That report refers to the danger of heating starch based foods beyond 100C - not specifcally about mirowaves - roasting and frying will have the same effect.

Microwave danger is a convenient headline

[Maladict]

That report refers to the danger of heating starch based foods beyond 100C - not specifcally about mirowaves - roasting and frying will have the same effect.

Microwave danger is a convenient headline

Actually since microwaving has replaced boiling for many people because it's "healthier" I think it's quite a sensible choice of headline.

[iakobski]

You could don your tinfoil hat and head off to Google: start with one of the best examples of pseudo-science I've seen in a long time

By comparison, microwaves from the sun are based on principles of pulsed direct current (DC) that don't create frictional heat; microwave ovens use alternating current (AC) creating frictional heat.

ect ect...

[TimO]

I understood it, that you couldn't get significantly above 100°C with a microwave cooker, since it only effects liquid water molecules.  Once the water gets to around 100°C and become steam, it no longer absorbs RF energy significantly, and stops getting any hotter.

This is also why you don't get colour changes in meat (eg chicken going white, and beef going brown), since these only occur at much higher temperatures than 100°C.

Likewise, relatively dry foods don't cook well in microwaves since they have little water to absorb the energy.

[pcolbeck]

How is it that some plates heat up a lot in the microwave and some don't ? I sit that they are slightly porous and have water trapped in them from the last time they were washed ?

[andrew_s]

How is it that some plates heat up a lot in the microwave and some don't ? I sit that they are slightly porous and have water trapped in them from the last time they were washed ?

I don't think it's water. You used to be able to get special browning plates for meat that got hot enough to act like a griddle (back when microwaves were new and people were trying to use them for everything).

Probably what I do most often is "baked" potatoes.
It's also handy for softening butter that's been in the fridge (put in with half a mug of water, zap on high, and poke at 10s intervals to see if it's soft enough yet).

[TimO]

It's not only water that absorbs RF energy, small metal elements (near to the wavelength of the RF oven's transmitter) will also absorb energy very efficiently.

A good test of this is an old CD-ROM.  Place it on top of a small cup of water (which acts as a dummy load, so you don't get a large amount of energy reflected back into the transmitter, damaging it).  The short sections of metal (aluminium) in the CD will absorb RF energy and eventually arc, generally breaking the track up into smaller and smaller elements, until they are no longer efficient aerials at this frequency.  The visible effect is a large amount of small sparks on the surface of the CD (the label side) for a few seconds.

I've done this several times with no damage to an oven.  It will melt the plastic slightly, so you will get a slight pong of melting plastic.  Of course, YMMV, so do this at your own risk, if you damage your oven "it's not my fault"^[tm].

[andym]

it heats from the inside

No it doesn't   It heats very much from the outside

I thought there was an array of hot and cold spots caused by constructive/destructive interference.  One way to demonstrate this (apparently) is the 'plate of cheese trick' to calculate the speed of light:
remove turntable, stick a plate of grated cheese in, turn on and watch where it cooks most.  Then with a ruler measure the distance between the hotspots, then check the actual RF frequency quoted on the sticker on the back, and finally calculate the speed of light.

After that, note where the hotspots are for the 'grape rocket races' etc.

[Chris S]

I thought the increase in colon cancer was down to people not taking care of the Big Three:

Exercise
Water
Fibre

Perhaps a diet rich in microwaved ready meals provides about zero of the third item, leading to problems long term. Also, those who live a ready meal life might claim not to have enough time for exercise - double whammy for the ol' poo factory.

[Maladict]

Plus green leafy veg.

[hellymedic]

Some of the vegetables that cook really nicely in a microwave contain plenty of water and a fair amount of fibre. They are not 'ready meals' though.

[Mike J]

Someone at work thought I was joking when I told them I don't have a microwave oven 

[hellymedic]

Someone at work thought I was joking when I told them I don't have a microwave oven 

Your colleague lacks imagination; my parents don't have a microwave either.
I don't have a TV...
... or a car.

[rogerzilla]

I think among the members of this forum you'll find a statistically unrepresentative number of:

- veggies
- left wingers
- TV-free households
- car-free households
- ecological crusaders
- etc.

[Really Ancien]

I think among the members of this forum you'll find a statistically unrepresentative number of:

- veggies
- left wingers
- TV-free households
- car-free households
- ecological crusaders
- etc.

And none of them are at all self righteous about it.

Damon

[hellymedic]

I think among the members of this forum you'll find a statistically unrepresentative number of:

- veggies
- left wingers
- TV-free households
- car-free households
- ecological crusaders
- etc.

And none of them are at all self righteous about it.

Damon

Hello Mr TV Licence Inspector. Do come in! Would you like to inspect the Non-TV in this room? The Kitchen? Upstairs? Feel free to wander round...
Oh, you really think I don't have a TV?
Goodbye, have a nice day...

I'd like to think I'm no more self-righteous about my non-TV than my non lizard skin high-heeled boots. There are some things I just don't have. TV comes up more in conversation though.

[Paul]

I think among the members of this forum you'll find a statistically unrepresentative number of:

- veggies
- left wingers
- TV-free households
- car-free households
- ecological crusaders
- grammar pedants
- etc.

And none of them are is at all self righteous about it.

Damon

 

[Adam]

I think among the members of this forum you'll find a statistically unrepresentative number of:

- veggies
- left wingers
- TV-free households
- car-free households
- ecological crusaders
- etc.

I'm definitely not at least 4 of those things, thank you very much!