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Author Topic: Microwaves and sparks  (Read 24365 times)

Offline Hadrian

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Microwaves and sparks
« on: 16/09/2006 19:33:19 »
Why do some metals spark in the microwave and some don't?

What you do speaks so loudly that I cannot hear what you say.


 

Offline Karen W.

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Re: Microwaves and sparks
« Reply #1 on: 16/09/2006 19:59:27 »
I did not know that they did! That's interesting. You do know that if you put metal items, pans ect. in a brown paper sacand close it aroun dish, you can microwave those also. My mother took many classes in microwave cooking.. She was a great cook!

Karen
 

another_someone

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Re: Microwaves and sparks
« Reply #2 on: 16/09/2006 20:42:17 »
quote:
Originally posted by Hadrian
Why do some metals spark in the microwave and some don't?



It makes very little difference what metal you put in a microwave, although the shape of the metal will make a difference.

Any metal object will behave like a radio antenae, and will absorb electrical energy from microwaves.  If the piece of metal has a gap that is roughly of the same order of magnitude in size to the wavelength of the microwave radiation, then one piece of the metal will be positively charged, and another will be negatively charged, and the gap inbetween will then be bridged by a spark.

A flat piece of metal with no gaps should not cause a spark (after all, the entire iside of the microwave oven is a large flat sheet of metal with no gaps).



George
 

Offline moonfire

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Re: Microwaves and sparks
« Reply #3 on: 17/09/2006 03:54:09 »
Some microwaves come with a metal rack in them....but aluminum foil is the general rule of don't do it!!!

"Lo" Loretta
 

Offline Karen W.

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Re: Microwaves and sparks
« Reply #4 on: 17/09/2006 06:31:55 »
I use foil, but in a brown paper sac!

Karen
 

Offline moonfire

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Re: Microwaves and sparks
« Reply #5 on: 17/09/2006 09:03:17 »
That is fine..it is not reflecting with the brown paper sack...the other way around would be a different story... I don't know why, but for some reason (of course, I am changing the subject)I am thinking about conductors...oh, never mind, think I will read a bit on them...kinda boring...LOL

"Lo" Loretta
 

Offline neilep

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Re: Microwaves and sparks
« Reply #6 on: 17/09/2006 20:29:48 »
Isn't  ' Microwave Cooking ' an oxymoron ?


Well, I know that's not strictly true....microwaves are great for vegetables and very very good for cooking fish..but you have to be careful.

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another_someone

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Re: Microwaves and sparks
« Reply #7 on: 17/09/2006 22:54:30 »
quote:
Originally posted by moonfire

That is fine..it is not reflecting with the brown paper sack...the other way around would be a different story...



Sorry, but this makes not the least sense.  The brown paper should be totally transparent to microwaves, and should have no effect whatsoever (excepting that if sparks were to fly, the paper might catch fire).

The main issue I can think of with regard to foil would be its flatness (a crumpled piece of foil will have more opportunity to spark than a flat piece).  Possibly you use the bag to help keep the foil flat?



George
« Last Edit: 17/09/2006 22:55:15 by another_someone »
 

another_someone

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Re: Microwaves and sparks
« Reply #8 on: 17/09/2006 22:57:33 »
quote:
Originally posted by neilep
Isn't  ' Microwave Cooking ' an oxymoron ?

Well, I know that's not strictly true....microwaves are great for vegetables and very very good for cooking fish..but you have to be careful.



OK, rice is vegetable - but I use it extensively for that.

It is much more difficult to cook meat in the microwave, but it really depends upon what type of meat dish you are cooking.  Anything that does not require seeling or frying would have a good chance of being cookable in a microwave - although, as you say, sometimes timing can be critical.



George
 

Offline Karen W.

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Re: Microwaves and sparks
« Reply #9 on: 17/09/2006 23:10:05 »
You can cook almost anything in the microwave...There is definitely an art and the recipes can be delicious. My mom became a pro at microwaving in different time temperatures in order to avoid having things rubbery or chewy!
She took a six month class at the commuity college!

Karen
 

Offline Karen W.

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Re: Microwaves and sparks
« Reply #10 on: 16/09/2006 19:59:27 »
I did not know that they did! That's interesting. You do know that if you put metal items, pans ect. in a brown paper sacand close it aroun dish, you can microwave those also. My mother took many classes in microwave cooking.. She was a great cook!

Karen
 

another_someone

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Re: Microwaves and sparks
« Reply #11 on: 16/09/2006 20:42:17 »
quote:
Originally posted by Hadrian
Why do some metals spark in the microwave and some don't?



It makes very little difference what metal you put in a microwave, although the shape of the metal will make a difference.

Any metal object will behave like a radio antenae, and will absorb electrical energy from microwaves.  If the piece of metal has a gap that is roughly of the same order of magnitude in size to the wavelength of the microwave radiation, then one piece of the metal will be positively charged, and another will be negatively charged, and the gap inbetween will then be bridged by a spark.

A flat piece of metal with no gaps should not cause a spark (after all, the entire iside of the microwave oven is a large flat sheet of metal with no gaps).



George
 

Offline moonfire

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Re: Microwaves and sparks
« Reply #12 on: 17/09/2006 03:54:09 »
Some microwaves come with a metal rack in them....but aluminum foil is the general rule of don't do it!!!

"Lo" Loretta
 

Offline Karen W.

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Re: Microwaves and sparks
« Reply #13 on: 17/09/2006 06:31:55 »
I use foil, but in a brown paper sac!

Karen
 

Offline moonfire

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Re: Microwaves and sparks
« Reply #14 on: 17/09/2006 09:03:17 »
That is fine..it is not reflecting with the brown paper sack...the other way around would be a different story... I don't know why, but for some reason (of course, I am changing the subject)I am thinking about conductors...oh, never mind, think I will read a bit on them...kinda boring...LOL

"Lo" Loretta
 

Offline neilep

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Re: Microwaves and sparks
« Reply #15 on: 17/09/2006 20:29:48 »
Isn't  ' Microwave Cooking ' an oxymoron ?


Well, I know that's not strictly true....microwaves are great for vegetables and very very good for cooking fish..but you have to be careful.

Men are the same as women, just inside out !
 

another_someone

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Re: Microwaves and sparks
« Reply #16 on: 17/09/2006 22:54:30 »
quote:
Originally posted by moonfire

That is fine..it is not reflecting with the brown paper sack...the other way around would be a different story...



Sorry, but this makes not the least sense.  The brown paper should be totally transparent to microwaves, and should have no effect whatsoever (excepting that if sparks were to fly, the paper might catch fire).

The main issue I can think of with regard to foil would be its flatness (a crumpled piece of foil will have more opportunity to spark than a flat piece).  Possibly you use the bag to help keep the foil flat?



George
« Last Edit: 17/09/2006 22:55:15 by another_someone »
 

another_someone

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Re: Microwaves and sparks
« Reply #17 on: 17/09/2006 22:57:33 »
quote:
Originally posted by neilep
Isn't  ' Microwave Cooking ' an oxymoron ?

Well, I know that's not strictly true....microwaves are great for vegetables and very very good for cooking fish..but you have to be careful.



OK, rice is vegetable - but I use it extensively for that.

It is much more difficult to cook meat in the microwave, but it really depends upon what type of meat dish you are cooking.  Anything that does not require seeling or frying would have a good chance of being cookable in a microwave - although, as you say, sometimes timing can be critical.



George
 

Offline Karen W.

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Re: Microwaves and sparks
« Reply #18 on: 17/09/2006 23:10:05 »
You can cook almost anything in the microwave...There is definitely an art and the recipes can be delicious. My mom became a pro at microwaving in different time temperatures in order to avoid having things rubbery or chewy!
She took a six month class at the commuity college!

Karen
 

Offline Hadrian

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Re: Microwaves and sparks
« Reply #19 on: 20/09/2006 16:45:59 »
Ok take a look at this But DONT try it unless ect.... [^][:p][^]


http://www.metacafe.com/watch/75874/amazing_microwave_fun/

What you do speaks so loudly that I cannot hear what you say.
 

Offline Hadrian

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Re: Microwaves and sparks
« Reply #20 on: 20/09/2006 16:45:59 »
Ok take a look at this But DONT try it unless ect.... [^][:p][^]


http://www.metacafe.com/watch/75874/amazing_microwave_fun/

What you do speaks so loudly that I cannot hear what you say.
 

Offline gecko

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Re: Microwaves and sparks
« Reply #21 on: 22/09/2006 03:09:33 »
untill i was 12 or 13 i used to always leave spoons and forks in when i microwaved stuff, and occasionally stainless steel bowls! i had never heard not to. then i got yelled at

nothing ever happened, not even sparks. even if sparks do happen, does it do any harm to the microwave?
 

another_someone

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Re: Microwaves and sparks
« Reply #22 on: 22/09/2006 04:19:21 »
I understand that one good way of generating sparks in a microwave is to put CD's in them - it does destry the CD in a spectacular way.

As for harm to the microwave over - unless something catches fire, it is unlikely to actually cause harm.

If you leave a piece of metal cutlery in the microwave, assuming no harm happens to the cutlery, then the biggest problem is that it may screen part of the food, thus leaving areas of the food uncooked (on the other hand, this can actually be used to good effect if you actually want to cook some parts of the food more than others).



George
 

Offline daveshorts

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Re: Microwaves and sparks
« Reply #23 on: 22/09/2006 11:01:29 »
Actually the main danger of putting forks etc in the microwave is that they get very very hot, (I was reading about some people using domestic microwaves to melt metals for casting purposes), you aren't expecting them to be that hot, and you could giver yourself a very nasty burn.

Wire wool also looks cool, but it does weld bits of molten iron to the inside of your microwave ;)

Aluminised crisp packets are really good - re a previous kitchen science at some point last year.

Light bulbs look really cool, but also get very hot as well. I have melted the glass a couple of times!
 

ROBERT

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Re: Microwaves and sparks
« Reply #24 on: 22/09/2006 16:53:22 »
quote:
Originally posted by another_someone

I understand that one good way of generating sparks in a microwave is to put CD's in them - it does destry the CD in a spectacular way.

George






" Microwave Magic
Arianna Gianola '09
Department of Computer Science
Microwaving a CD for 10 seconds reveals the concentric circle pattern of the CD surface, which is otherwise undetected by the naked eye. "

http://www.princeton.edu/~artofsci/gallery2006/view.php%3Fid=47.html
 

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Re: Microwaves and sparks
« Reply #24 on: 22/09/2006 16:53:22 »

 

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