The Computer as Microwave? 32
Clan Hanna asks: "With the newest processors that AMD and Intel have released, running at 1.0 gigahertz, chip designers may soon have a new problem on their hands more than can simply be solved by placing a bigger heatsync on the motherboard. Microwave frequencies run from 1 gigahertz to 1 terahertz. Currently processors heat up because they emit infrared radiation, but what is going to happen when they start to emit -microwave- radiation? I'm sure chip designers think about this in the back of their minds, but I'm just wondering if they have considered any real world solutions. If so, I'd love to find out about them."
Re:apples and oranges (Score:2)
If there just a few milliwatts of radiated power, it should not be enough to burn tissue. Compare to the kilowatt of a microwave oven antenna, which was designed to radiate its power.
Anyhow, the microwaves or xrays from a computer and its monitor will not kill a person. Sitting in the chair across from the monitor for extended periods of time may cause fatigue, depression, alchoholism, and madness, which is another story.
Re:This is Slashdot? (Score:1)
Unfortunately, the quality of the answers varies over a wide range and the person asking the question (who wouldn't be asking if they were already experts in the area) can have difficulty separating the wheat from the chaff, especially since so many of the answers fall somewhere in between.
Here's one helpful hint: the more a particular post flames previous posters as idiots, et cetera, the more likley it is that *their* answer is based on an incomplete understanding of the issue at hand.
Flatscreens (Score:3)
There is basically a VERY bright lamp that is shown through a number of colored LCD screens. The Plasma displays work similarly. Electroluminescent displays emit even less...
Any of these is much better than the electron gun in the back of CRTs. (basically a small particle accelerator..)
Of course, if you are truly worried about radiation poisoning: never fly (cosmic rays), don't get X-rays (X-rays), stay away from cinderblocks (alpha-emitter), ditch that glow-in-the-dark watch (radioactive), discard you're smoke detector (radioactive), stay away from the Northeast (radon, radioactive)...oh hell, just leave the planet beacause a couple of years ago, a satellite with a nuclear reactor onboard burnt up on re-entry and spread plutonium over the entire planet, of course, interplanetary travel opens up another can of worms...
=)
Re:apples and oranges (Score:1)
-Smitty
Microwaves aren't that bad (Score:3)
However, to my understanding all modern computers are supposed to comply with FCC Part B regulations. This means that they don't emit anything that could cause interference or other harm. In other words, you have nothing to worry about unless you run the system with the case open.
Re:I get a little upset... (Score:2)
"Give the anarchist a cigarette"
Re:Flatscreens (Score:1)
Use AOL CD Test (Score:1)
We've all made coasters in the microwave oven out of AOL CDs, right? If a computer was creating significant amounts of RF, we'd be seeing the same sparks crawling around various metal components.
Obviously, computer designers would have to block any such leakage or all the electronics would be destroyed.
Re:Problem (Score:1)
BTW, how does running systems without a lid make magazine reviewers better? Or power users? A properly designed (take IBM's PS/2 line) PC case must have the lid in place in order for air to flow correctly through the system to keep everything cool. Without a lid, the flow is changed an the intake/exhaust fans can't operate properly.
Problem (Score:1)
Chris Hagar
Re:Problem (Score:1)
I was thinking that a lot of cases/entire system/fanning is/are not designed properly and so in many systems keeping the case off might keep it much cooler. Also, if someone is doing any sort of upgrading, I wouldn't want to pop the case back on before I boot the computer up to make sure it worked correctly.
Chris Hagar
Re:apples and oranges (Score:2)
It's even more mundane than that. (Score:3)
Cliff wrote:
Well, Cliff ol' boy, I've got news for you: processors don't heat up because they emit infrared radiation, they emit infrared radiation period. So do you. A square meter of blackbody radiator at skin temperature emits about 450 watts[1], mostly in the infrared. However, some of it is actually at longer wavelengths, down into the microwaves. (YOU are a MICROWAVE EMITTER! And if you don't pay me $10,000, I'll TELL YOUR FRIENDS AND FAMILY!)This property is used all the time. One of the methods for sensing temperature remotely is with microwave radiometry; it's how the surface temperature of Venus was determined before probes were ever sent there, and the bulk temperature of Earth's atmosphere is measured by satellite sensors using that same technique to this very day.
You don't have to worry about microwave emissions from a CPU chip, even if it's running at a couple of GHz. The chip carrier itself usually has a metal plate for heat dissipation, forming a ground plane; ground planes provide "equal and opposite" mirror currents and mostly cancel the emissions. The metal lid is another ground plane. Even at 3 GHz, a wavelength is 10 centimeters; most traces on the chip are but a fraction of a millimeter long, and don't have the physical size to radiate well. What radiation they do emit will be cancelled by image currents in the ground planes and confined inside the chip carrier until it is absorbed by resistance in the silicon itself. The biggest issue is emissions from leads which go out of the chip itself, and those are usually running at a much lower frequency than the CPU core. What gets out is microwatts at most; this can be troublesome, but danger to people is way down on the list of concerns.
I think the summary is, no need to worry yet but you should probably do some reading so that you will know if and when you should worry in the future.
[1] Blackbody radiation flux is determined by the absolute temperature and Boltzmann's constant; the formula for the radiation per unit area is flux = 5.67*10^(-8) W/m^2/K^4 * temperature^4, so the heat flux increases as the fourth power of temperature.
--
Re:apples and oranges (Score:1)
apples and oranges (Score:3)
Wait a minute... (Score:5)
Anyway, even if it did, the high-amplitude microwaves in an oven are stopped by rather thin sheets of steel. And the amplitude from the CPU must be lower. Remember, your oven draws multiple kW, while I damn hope your CPU keeps below 100W. (Otherwise, you have an Alpha, and I WANT IT!
-
Re:Flatscreens (Score:1)
At least in Finland mob. phones meet the radiation regulations only because of the fact that GSM sends data in bursts - half the time there's no radiation, half the time there's more radiation than what would be allowed continuously.
Luckily (at least for the phone industry) the technology develops in such leaps, that the long-term health effects haven't got the time to develop... yesterday NMT's, today GSM/PCS, tomorrow GPRS and stuff. And as development continues and the frequencies go up, the transmitting power goes down.
I think I should be more worried about using laptop, anyway. Not for the TFT, but for the PIII 450 MHz ticking at my groin...
Re:Problem (Score:1)
my case == immediate 20+ degree(F) increase in cpu temp...
Re:Wave shape (Score:2)
A lot of people in the posts above are suggesting that the low power means that this is nothing to worry about, just more un-informed hyteria. While I totally admitt to the un-informed part, you have to realize that the "always-on" nature of the computer means that damage can accumulate over a long period of time. I spend more than half my waking hours (at least during the week) in a room with more than 3 computers within a few feet. Many people (especially college students) sleep in a room with computers close to the bed.
I don't understand the very much about the physics of how RF does biological damage; I've read about how "harder" radiation, such as gamma and particle radiation, works. Basically, you want to assure yourself that the radiation is not enough to produce a free radical next to a DNA strand, so that the radical can combine with the DNA and break it. Now, because of the way that your cells repair DNA, you can tolerate a certain amount of damage; kind of like an error-correcting code will keep all the information as long as only a certain portion of the bits are lost or flipped.
Particle radiation can make chemical changes just by hitting the molecules, but RF level radiation does damage (or can do damage) by simply heating an area, which can damge DNA or produce free radicals or oxygen which will damage it.
So while I think the power observations are very pertinent, I don't think they can be the basis of dismisal of the danger. I think you have to be able to say that the amount of heating your body might receive from several computers 24/7 is on the order of what you get anyway from the electrical system, or something like that. There must be some effect, but as long as it is below what you can measure it is probably below the level at which DNA repair will protect you from cancer.
So one final question -- someone (the first post) mentions that ham radio hobbists get cataracts more often. What is the physical mechanism that causes that ? I know that exposure to too much UV light is supposed to increase the incidence of cataracts. I have glasses with an anti-UV coating that the eyeglass specialist recommended on those grounds.
Re:Wave shape (Score:2)
So what is it about the EM radiation that causes the damage ? Why is the EM from a leaking microwave oven bad for you ?
This reminds me of that whole debate about whether living in the proximity of powerlines and transformers increased the incidence of cancer. No one ever made a convencing study as I remember, and they never did offer a good physical description of how that energy could harm you.
I know one professor who teaches a bio-electronics class (6.121J) and I can ask him.
Re:Microwaves aren't that bad (Score:3)
Before I buy a chip running at that frequency, I'd like to see some specs on exactly what I can and cannot do with it. If I need to keep it in a case that meets certain specifications, I should know that; is it safe to just not screw in the panels on the case, or should I always have everything tightened up before powering on ? I would prefer to have the processor package do all the necessary shielding for me.
What about those guys doing wearable computing ? I know Steve Mann and that Media Lab freak club were walking around MIT with computers butt packs for a while. For what processors they had there was probably no danger, but with a gigahertz plus processor hanging over the genital area or close to your body at all -- cancer at least only affects the person who decided ot wear the thing, a birth defect punishes a child for the parent's negligence.
I would prefer to get the information from an independent source; if AMD or Intel said that it was dangerous if not run as shipped, the information would be suspect because they might just be trying to scare off the overclockers, and if they said it would always be safe, they might just be hiding the truth for marketing reasons.
So I would like to see some overclockers and someone with access to the right kind of equipment test the newest processors at some really high clock rates (even if the processor was unstable at that rate) and publish the results. The "right kind of equipment" is the kicker here -- I've heard those electrical isolation chambers they use to test the meeting of FCC specs are very expensive.
I am planning to buy a really fast alpha in a few months after I move to my new place. I've heard rumours of 1.4 and 1.6 GH by then. I'll just get some really long keyboard and monitor cables until I see some trustable information on this issue. Whatever the manufacturer says, I'll still trust 1/R^2 -- you can't beat basic physics.
Incidentally -- does anyone know if these expensive flat screen monitors produce signifcantly less EM radiation than the good old cathode ray tube ? I think the fact that they use less power is a good sign.
Re:I get moderately concerned... (Score:1)
-rt-
I get moderately concerned... (Score:2)
-rt-
I get a little upset... (Score:4)
Re:Wait a minute... (Score:1)
PC oven == next killer app (Score:2)
Re:Wave shape (Score:1)
So while I think the power observations are very pertinent, I don't think they can be the basis of dismisal of the danger. I think you have to be able to say that the amount of heating your body might receive from several computers 24/7 is on the order of what you get anyway from the electrical system, or something like that. There must be some effect, but as long as it is below what you can measure it is probably below the level at which DNA repair will protect you from cancer.
Heating? The amount of heating you get by turning your thermostat up a few degrees has to be orders of magnitude greater than any heating caused by RF radiation.
Wave shape (Score:1)
--Alex,
Re:I get moderately concerned... (Score:1)
Possible future scenario (Score:1)
"After two more minutes of cracking RC5 keys, it should be ready!"
I can wish, can't I?
blocking microwaves isn't that hard (Score:1)
Re:Problem (Score:1)