Are microwaves bad for you?

[gavreid]

That is the only risk with them though, a breach in the oven cavity large enough for the waves to pass through.

Classically yes but that's not quite true. Even though the grid on the door is considerably smaller than the wavelengh of the micowaves, you will get some leakage through it.This is called an evanescent field, which falls off in intensity very sharply (exponentially) with distance. That is why you should stand back and not press your nose to the door!

 

[linnfomaniac83]

They are also very useful for nutters like me who use them to make a small Tesla coil. When you chuck out an old microwave rip out the xformer and flog it on evilbay.

Cheers,

DV

I’ve ripped one out and made a vicious Jacobs ladder before but didn’t keep it assembled because it was pretty dangerous... I might also have connected one to some scrap PCBs for scientific reasons.

 

[linnfomaniac83]

Classically yes but that's not quite true. Even though the grid on the door is considerably smaller than the wavelengh of the micowaves, you will get some leakage through it.This is called an evanescent field, which falls off in intensity very sharply (exponentially) with distance. That is why you should stand back and not press your nose to the door!

I guess that’s why there is an inch or so between the grid and the Perspex window.

 

[Darth Vader]

I’ve ripped one out and made a vicious Jacobs ladder before but didn’t keep it assembled because it was pretty dangerous... I might also have connected one to some scrap PCBs for scientific reasons.

For some reason this reminds me of Bela Lugosi. Somewhere I have a 50KV Xformer that I used for a Jacobs ladder but as you say they are dangerous to leave lying around. There were so many turns on the secondary winding and a decent iron core that just by putting an Avo across to check continuity could give you a big belt!

Cheers,

DV

 

[stevec67]

I remember a radio programme on the then new fashion of microwave ovens reminding users to leave the food to rest for a few moments after cooking as "the microwaves are still cooking the food for a while after you switch off".

They mean that the heat transfer processes continue by conduction through the food. There are no residual microwaves left in the food, any more than there is residual light in a room after you turn off the light.

 

[blossomchris]

I remember hearing this too. Was it because they caused interference with sensitive measuring equipment or did they upset some covert monitoring system?

I faintly recollect an awful comedian using that line, which I found amusing. I have no idea, I am afraid regarding interference.
We have not owned a microwave for 25 years and have no desire to obtain another.

Bloss

 

[stevec67]

We did an experiment at step daughters' parents day to measure the wavelength of microwaves with a piece of chocolate; something about a standing wave and the chocolate melted in 11.5cm stripes?

This ia a favourite demo, easy to do when you remove the turntable. This is why you need a turntable. The hot spots are 11.5cm apart, representing the peaks and troughs of the standing wave. There is no heat at the point where the waves are crossing the zero point, just like there is no water movement in the middle bit of a standing water wave.

 

[stevec67]

We have not owned a microwave for 25 years and have no desire to obtain another.
Bloss

I have owned several over the course of the last 25 years and use them every day, even if it's only to warm up plates. Tonigt's use was warming up something I'd cooked earlier and kept in the freezer. If mine went bang tomorrow I would replace it within the week.

 

[blossomchris]

I have owned several over the course of the last 25 years and use them every day, even if it's only to warm up plates. Tonigt's use was warming up something I'd cooked earlier and kept in the freezer. If mine went bang tomorrow I would replace it within the week.

We do freeze our cooking, and to revive it we prefer the hob/oven and slowly bring it round, whilst doing other bits and pieces.
I sometimes wear an apron, depending on the chores.

Bloss

 

[stevec67]

Dinnertime chez Bloss:
http://www.gettyimages.co.uk/detail/photo/beautiful-french-maid-royalty-free-image/157618866

 

[Barrymagrec]

They mean that the heat transfer processes continue by conduction through the food. There are no residual microwaves left in the food, any more than there is residual light in a room after you turn off the light.

Just so.

 

[Jim Audiomisc]

If you don't connect a longer waveguide, the electromagnetic radiation will propagate in all directions from the end of the waveguide built into the device which on its own cannot collimate the beam.

OK. So you used "front" to mean "open end of the waveguide" or "where the waveguide should be connected".

 

[Mike Reed]

sometimes wear an apron, depending on the chores.

But that's just your o pinny on, Bloss.

 

[timola]

I guess that’s why there is an inch or so between the grid and the Perspex window.

I don't know if this is an urban myth or not (probably is), but I recall hearing a story that in the early days of microwave ovens there were some commercial ovens that could be used without closing the door (or fully pushing it down from above). When a lot a workers complained about Kidney problems its was noted that the oven was on the counter behind the workers.

 

[gintonic]

I don't know if this is an urban myth or not (probably is), but I recall hearing a story that in the early days of microwave ovens there were some commercial ovens that could be used without closing the door (or fully pushing it down from above). When a lot a workers complained about Kidney problems its was noted that the oven was on the counter behind the workers.

bit like the cataract issues (myth or not) caused by leaky door seals and people staring at their food rotating on the turntable

 

[linnfomaniac83]

I don't know if this is an urban myth or not (probably is), but I recall hearing a story that in the early days of microwave ovens there were some commercial ovens that could be used without closing the door (or fully pushing it down from above). When a lot a workers complained about Kidney problems its was noted that the oven was on the counter behind the workers.

I wouldn’t want to be too near to one running with the door open, that’s not good at all. I’m not sure why it would cause kidney problems specifically but high exposure would definitely cause some deep burns.

 

[MikeMA]

I've read online that microwaves are bad for your health and just wondered If there Is any truth In It?

Mrs MikeMA thinks so. We keep ours in the garage.

 

[Seeker_UK]

OK. So you used "front" to mean "open end of the waveguide" or "where the waveguide should be connected".

Not sure what you're asking but to clarify what I wrote.

A small waveguide is usually part of the construction of a magnetron.

As soon as the waves leave that short waveguide, diffraction will cause them to propagate out in a 'cone'.

To control that propagation, a second, longer waveguide needs to be attached to the magentron's own integral waveguide.

 

[slavedata]

I remember once when teaching BTEC Computing one of my students complaining about intermittent wifi drop outs. We asked where the router was.... on top of the microwave in the kitchen. Sounds a good location.

 

[Jim Audiomisc]

Not sure what you're asking but to clarify what I wrote.

I asked because I'm familiar with using magnetrons, klystrons, and BWOs. I knew how the output is taken via a guide or coax, but was puzzled by what you meant by "front".