Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Test Microwave for Radiation Leakage

ismymicrowaveleaking.isotropic.us

Post reply on HN
Print view View original

101–110 of 110 posts

Re: Test Microwave for Radiation Leakage

#101

Post by eyelidlessness »

verve_rat wrote: post #98
eyelidlessness wrote: post #64

Earlier quoted context omitted.

Calling people idiots for making mistakes is about the most boring thing I can imagine. I agree it shouldn’t be deleted, and that it’s interesting. But everyone flubs it from time to time, even people who like to think they’re above that.

There is a difference between making an understandable mistake and doing something that should make you ashamed for being that dumb. Nuking your phone in the microwave is in the same category as baking it in the oven. You really shouldn't be surprised when you don't have a working phone anymore. I don't think it is wrong of us to expect better from a bunch of adults. They should know better.

Look. Calling people idiots or stupid is just a shitty thing to do. Shaming people for not having the same information, recall, thought process as you is never going to help them better meet your expectations of their mental faculties. It might even have the opposite impact to some degree, depending on how they react to the insult.

It doesn’t matter one bit whether you think someone should think it through the way you would. People routinely disappoint on that front, and it’s almost always because people have expectations that are closer to their own experience and thought process than they realize.

Personal anecdote, for your judgy amusement: a couple weeks ago I fell hard on the pavement of a very busy arterial road. I was running behind schedule, hurriedly looking for a chance to beat the crosswalk signals if there was a safe gap in traffic. I was paying attention to the height of the curb as I went, because it’s unusually high off the road at one intersection then gradually gets closer to a normal height in the course of a block. Trouble is, I wasn’t paying close enough attention, and I misjudged the height by about a foot.

I stepped into the road in a gap in traffic, but there wasn’t anything under my foot when I stepped down. Before I know it, I was sprawled out on the street, gratefully with a busted up hand not a busted up head. And more gratefully, with an audience sitting at the next red light, not still traveling towards where I fell.

I was, indeed, embarrassed by all of this. And any one of the people who saw it happen surely could have called me stupid. Maybe they even did, but I’m happy they kept it to themselves at the time. I realized my error as soon as it happened. What good would have come of insulting me on top of that?

Re: Test Microwave for Radiation Leakage

#102

Post by hilbert42 »

alanbernstein wrote: post #99
hilbert42 wrote: post #97

Earlier quoted context omitted.

It's quick and easy and less dangerous (and more final) than a hammer! I've been known to change my mind half way through destroying something when I think of another use for it - the microwave method ensures that the part of me that doesn't like throwing out electronic things that still work always gets thwarted. The idea of microwaving electronics came to me a long while ago for very different reasons. In the early…

Fair enough! Personally, when I reuse broken electronics, it's often because I'm scavenging more mechanical parts like ports and switches. I think those would tend to survive either method, as long as you're not utterly destroying the device.

Right, scavenging for mechanical parts is also my main aim (LSIs etc are now so specific they're useless as spares). For example, only a week or so ago I had to replace a PCB-mounted USB connector on one of my PVRs and I scavenged its replacement from an old mobo. :-)

Re: Test Microwave for Radiation Leakage

#103

Post by eyelidlessness »

ganzuul wrote: post #87
eyelidlessness wrote: post #65

Earlier quoted context omitted.

I have read this several times over and have no idea how you could mean it which isn’t sexist af. Edit: okay maybe I can imagine you’re saying that women have been competent in the kitchen and men [/other gender identifying people?] have demonstrated not being as competent. I’m really trying to stretch credulity to read this in good faith.

Women are widely known to be more attentive and dexterous in e.g. electronics assembly. Surely this translates to the domestic kitchen as well. Sexist? Please, shove that word. This is simple facts about life.

> Sexist? Please, shove that word.

Respectfully, fuck no.

Re: Test Microwave for Radiation Leakage

#104

Post by verve_rat »

eyelidlessness wrote: post #101
verve_rat wrote: post #98

Earlier quoted context omitted.

There is a difference between making an understandable mistake and doing something that should make you ashamed for being that dumb. Nuking your phone in the microwave is in the same category as baking it in the oven. You really shouldn't be surprised when you don't have a working phone anymore. I don't think it is wrong of us to expect better from a bunch of adults. They should know better.

Look. Calling people idiots or stupid is just a shitty thing to do. Shaming people for not having the same information, recall, thought process as you is never going to help them better meet your expectations of their mental faculties. It might even have the opposite impact to some degree, depending on how they react to the insult. It doesn’t matter one bit whether you think someone should think it through the way yo…

Honestly, I don't think your anecdote helps the point you are making. Yes well all do stupid things from time to time. I have done stupid things. I'm arguing that there are times when we should should show kindness and compassion and there are times when, fuck it, you were an idiot, you should know better, and I am going to judge you for it.

There is an idea floating around that all judging is bad. I reject that. It might not be helpful to the person being judged an idiot, but the expectation that I should change my view of others to help them with their learning is... I'm struggling to find the right words here... an imposition?

I think it is the difference between being kind to everyone and not being unkind to anyone.

Everyone judges people all the time, to claim otherwise is a lie. I will continue to judge people by their actions, whether or not they improve by some metric is not my aim, nor my problem.

Re: Test Microwave for Radiation Leakage

#105

Post by ganzuul »

Retric wrote: post #95
ganzuul wrote: post #89

Earlier quoted context omitted.

> A Federal standard (21 CFR 1030.10) limits the amount of microwaves that can leak from an oven throughout its lifetime to 5 milliwatts (mW) of microwave radiation per square centimeter at approximately 2 inches from the oven surface. So you were off by a factor of 200, and you can see that my referencing -40dB of attenuation was an underestimate. I do wonder what details it was that you thought you might recall. Qu…

You’re way off, that’s 5 milliwatts per square cm times the surface area. A 1 foot cube, has 6 faces of ~30 cm * 30 cm or 5,400 cm2. 5,400cm2 * 5mw = 27 watts. Of course 2 inches from the surface is a significantly larger box. Of course that’s a legal maximum, most devices should be well below it.

You can melt stuff with 27W. Doesn't pass the smell test.

Re: Test Microwave for Radiation Leakage

#106

Post by Retric »

ganzuul wrote: post #105
Retric wrote: post #95

Earlier quoted context omitted.

You’re way off, that’s 5 milliwatts per square cm times the surface area. A 1 foot cube, has 6 faces of ~30 cm * 30 cm or 5,400 cm2. 5,400cm2 * 5mw = 27 watts. Of course 2 inches from the surface is a significantly larger box. Of course that’s a legal maximum, most devices should be well below it.

You can melt stuff with 27W. Doesn't pass the smell test.

Sunlight is 93w/square foot, this would be under 4.5w/square foot good luck melting something at room temperature with that. I think you have a poor intuition about the difference between point sources and energy across an area.

Anyway, math is math but presumably this is why that’s the legal limit. It’s low enough to be safe while high enough not to be expensive for manufactures.

Re: Test Microwave for Radiation Leakage

#107

Post by MertsA »

manwe150 wrote: post #82
NikolaNovak wrote: post #80

Earlier quoted context omitted.

Am I wrong in ignorant understanding that if some radiation leaked, its' effect would largely be about heating affected body parts, which presumably you'd feel as, you know, heat; as opposed to some magical or teryfing "thing"? In other words, why is microwave leaking worse than e. G. My oven leaking heat? Is potential small amount of microwave radiation In some specific way worse than feeling the heat when you open…

IR radiation is stopped very easily, eg by dead skin cells. Higher energy radiation, eg microwaves, can penetrate much deeper into your body and start causing damage to living tissues.

On the contrary, IR penetrates past the dermis. Also, IR is much much higher energy than microwaves although both are non-ionizing radiation and will only result in heating. The amount of heating you get from the sun spread over a square meter is close enough to the power output of a microwave. Even with the lower attenuation to 2.4GHz vs 240THz the peak heating is still occurring on the surface. You'll probably notice if you're being heated with a couple hundred watts of power. If you don't notice then you're absorbing so little power that there's no chance of any injury. You'd need to raise the temperature of your organs by at least 10 degrees to cause any organ damage and your skin temperature would be so high by that point that you'd already have burns and any sane person will instinctively move away from the heat source causing them pain.

It would take far too long to heat up hot enough to cause more than skin burns and nobody would ever stand there long enough to even get a skin burn to begin with. Any sink presents a much more serious risk of injury than a broken microwave. A hair dryer is more dangerous.

It seems like you might be extrapolating the speed of heating some piece of food and assuming it could possibly heat someone outside of the microwave at the same rate. It can't. The only reason small things heat up quickly is because in a closed microwave the walls reflect the microwave energy many many times before it's eventually absorbed by the food. It's a high Q factor resonant chamber. Effectively when there's little energy being absorbed or escaping the intensity of the microwave radiation is multiplied many times over until the energy being absorbed is equal to the energy being put in. If the door is removed it's just going to bounce out and you get none of the massive jump in intensity that you get with the door closed and only a small 1/2 lb of food inside.

Re: Test Microwave for Radiation Leakage

#108

Post by manwe150 »

MertsA wrote: post #107
manwe150 wrote: post #82

Earlier quoted context omitted.

IR radiation is stopped very easily, eg by dead skin cells. Higher energy radiation, eg microwaves, can penetrate much deeper into your body and start causing damage to living tissues.

On the contrary, IR penetrates past the dermis. Also, IR is much much higher energy than microwaves although both are non-ionizing radiation and will only result in heating. The amount of heating you get from the sun spread over a square meter is close enough to the power output of a microwave. Even with the lower attenuation to 2.4GHz vs 240THz the peak heating is still occurring on the surface. You'll probably noti…

https://en.m.wikipedia.org/wiki/Microwave_burn

Re: Test Microwave for Radiation Leakage

#109

Post by MertsA »

manwe150 wrote: post #108
MertsA wrote: post #107

Earlier quoted context omitted.

On the contrary, IR penetrates past the dermis. Also, IR is much much higher energy than microwaves although both are non-ionizing radiation and will only result in heating. The amount of heating you get from the sun spread over a square meter is close enough to the power output of a microwave. Even with the lower attenuation to 2.4GHz vs 240THz the peak heating is still occurring on the surface. You'll probably noti…

https://en.m.wikipedia.org/wiki/Microwave_burn

I'd suggest looking at the section on Adults and Microwave ovens. Over many cases of people being exposed to an open and operating microwave oven the only injuries were burns close to the surface and peripheral neuropathy from placing their hands inside the oven getting a substantial portion of the total power on a small area. The more serious injuries on that page were a result of much more powerful and more intense microwave sources at different frequency bands. If you stick your head into a high powered waveguide, you're going to have a bad time.

In fairness I was surprised to learn that nerve cells absorb a fair bit more than skin and fat leading to quicker nerve damage. All things considered though, I stand by my statements, hot water at a sink presents a much bigger risk given the frequency of exposure and the risk of burns.

Post reply on HN