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Wireless Networking Media Television Hardware Science Technology

How Bad Can Wi-fi Be? 434

Posted by Zonk
from the good-thing-we-have-real-experts-here dept.
An anonymous reader writes "Sunday night in the UK, the BBC broadcast an alarmist Panorama news programme that suggested wireless networking might be damaging our health. Their evidence? Well, they admitted there wasn't any, but they made liberal use of the word 'radiation', along with scary graphics of pulsating wifi base stations. They rounded-up a handful of worried scientists, but ignored the majority of those who believe wifi is perfectly harmless. Some quotes from the BBC News website companion piece: 'The radiation Wi-Fi emits is similar to that from mobile phone masts ... children's skulls are thinner and still forming and tests have shown they absorb more radiation than adults'. What's the science here? Can skulls really 'absorb' EM radiation? The wifi signal is in the same part of the EM spectrum as cellphones but it's not 'similar' to mobile phone masts, is it? Isn't a phone mast several hundred/thousand times stronger? Wasn't safety considered when they drew up the 802.11 specs?"
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How Bad Can Wi-fi Be?

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  • by icthus13 (972796) on Tuesday May 22, 2007 @08:43AM (#19220395)
    Think of the children!!!
    Seriously, it's sad that supposed "news" programs air things like this just to get ratings. What's even sadder is that lots of people believe them, so tech-savvy people like us now have to spend time explaining to Aunt Jane that the big evil wifi will not give her cat cancer.
    • by mario_grgic (515333) on Tuesday May 22, 2007 @08:55AM (#19220599)
      give her cat cancer

      Is that when there's a cat growing out of her chest cancer?
      • by Applekid (993327)
        I think there was a joke about "women parts" embedded in there somewhere.

        (anyone else have visions of the Sarlacc?? *shudder*)
    • Re: (Score:3, Informative)

      by malsdavis (542216)
      Panorama isn't a "news" program, it's an investigative reporting program, which is quite different.

      Towards the end of the program in question, they did start to admit more and more that there is absolutely no evidence or even much likelihood of harm from Wi-Fi, which was good although it was maybe too little, too late. My (and I think many others') main issue with the program was their over-use of the scare word "radiation" in a way that implied every Wi-Fi router is a mini unshielded nuclear reactor.

      But, I
      • by CmdrGravy (645153) on Tuesday May 22, 2007 @10:29AM (#19222177) Homepage
        The problem with programs like this is that it's likely create the same effect the reporting on MMR Vaccinations did. In that case despite massed ranks of scientific and medical studies and scientists saying there was no danger from MMR vaccinations a large number of people chose to believe that either there was a danger or there could be well be a danger based on reports in the media.

        The trouble is that it's impossible to prove absolutely that wireless emissions are 100% safe and any good scientist if pressed will agree with that. A lot of people then choose to think that this must indicate there is a real danger and believe the shrieked warnings of people who think they have some disease absolutely caused by their wireless router. Pointing out that there is no evidence of wireless emissions being harmful is a wasted excercise on these people who only seem to be able to think in black and white

        "No evidence yet !" they wail "But you wont tell me it's 100% safe either ! Destroy all wireless !"

        What's often missing is a sense of perspective, cars are extremely dangerous and kill hundreds of thousands people a year throughout the world but most people are perfectly happy to drive them or walk in the vicinity of them.

        I think the difference might be that people can easily see the dangers posed by cars themselves whereas there is no visible evidence of MMR vaccines or phone masts killing people so people have no way of easily assesing the threat and instead have to rely on people telling them things they don't really understand.

        Obviously we can't do anything about people choosing not to buy wireless routers for use in their own homes because of a fear of the perceived risks they pose but we should be able to stop these people stopping the use of these things in society in general, e.g. in schools where we should use proper standards of evidence for assessing threat levels and not allow even a majority of parents to make changes unless they can present proper evidence for their beliefs.
        • Re: (Score:3, Insightful)

          by malsdavis (542216)
          I agree, but the various MMR Vaccine scare programs were far more sensationalist than the recent Panorama Wi-Fi one, they were almost bordering on criminal misrepresentation / fraud imho. They were presented more along the lines of "This child has Autism, he started developing symptoms in the months after receiving MMR and his mother - despite having absolutely no medical background or valid reason - blames MMR!". You show parents of babies a bunch of disabled teenagers and you can have them believing anyth
          • Re: (Score:3, Interesting)

            by ZombieWomble (893157)
            I wouldn't so readily dismiss the potential effects of this program out of hand - while it's not quite so serious as the potential epidemic outbreaks which would be offered by people boycotting vaccinations, there is enough people who don't really understand the issue or don't care that the nutjobs who are morbidly terrified of it ("Wifi is the new asbestos! Run for your life!") to get it removed from pretty much every public place until "further research" is done to prove it's safe. Several of the national
        • Re: (Score:3, Interesting)

          by Domo-Sun (585730)

          Um, if you can't prove that it's 100% safe, then why are you so upset like there IS no threat? You have to be honest with people. Some people will be crazy no matter what you do.

          And if over-reaction is such a bad thing, why don't you stop. Just like you, when I hear people over-reacting, I start to suspect they're crazy, especially when they start telling me about how safe cars and sharks and vaccines are, relatively, because it starts to sound like they're bullshitting me on their side, when all they have

      • by Azathfeld (725855) on Tuesday May 22, 2007 @12:02PM (#19223577)
        Friggin' fake news. I'm going to go strap a thousand wireless routers to their offices so that they all die of fake cancer.
    • If you're talking about cell towers, the maximum radiated wattage is a mere 16 Watts. For most "normal" WiFi, the max is about 100mW, or 0.1W. In reality, it may be a mere 28mW or 0.028W (Linksys, for example).

      So, on one hand, 16W (cell) vs 0.028W (WiFi) is quite the difference.

      However, the distance falls off in a square inverse fashion. If you're 1M away, you get 100 times the power as if you're 10M away, so as for how much power you get, it's all relative to distance.

      If you are 1M from your Linksys and
  • What crap. (Score:5, Insightful)

    by Mockylock (1087585) on Tuesday May 22, 2007 @08:43AM (#19220405) Homepage
    All day we're around Microwaves, XRays, High voltage lines, lights, televisions and Radio signals. There are TONS, of course... but how much more is actually from outside the atmosphere?

    The only thing that's frying our kid's brains are their ideas. I'm not overlooking child safety, but there are WAY more harmful waves out there than WiFi.

    In the meantime, their children are outside getting burnt without sunscreen.
    • by cerberusss (660701) on Tuesday May 22, 2007 @09:09AM (#19220839) Homepage Journal

      their children are outside getting burnt without sunscreen.
      You think that's bad? The other day, I saw a kid browsing Slashdot in the library.

      *shivers*

      OMG SOMEBODY THINK OF THE CHIIILDREN
      • Re: (Score:3, Funny)

        by Bomarrow1 (903375) *
        OMFG!!!eleven!
        I'm a child, I'm reading slashdot. I have one WiFi access point less than a foot from my head and another 10 meters away. I can feel it burning. Argh the pain. In fact just to make sure that I don't mutate (lots of fun programs on that as well) and polute the gene pool I'm gonna electrocute myself now.

        But in all seriousness its never harmed me...
    • by tpholland (968736) on Tuesday May 22, 2007 @10:05AM (#19221801)

      All day we're around Microwaves, XRays, High voltage lines, lights, televisions and Radio signals.

      Please stop, it's too horrible! The worst of it all is that my PC is as we speak radiating heat.

      That's the same kind of radiation that is used in conventional ovens!

      It can cook stuff to death!

    • Re:What crap. (Score:5, Interesting)

      by vertinox (846076) on Tuesday May 22, 2007 @10:14AM (#19221941)
      All day we're around Microwaves, XRays, High voltage lines, lights, televisions and Radio signals. There are TONS, of course... but how much more is actually from outside the atmosphere?

      Actually, in the late 1890's and early 1900's people who worked in the field of XRays often died from over exposure of radiation. They simply didn't know what they heck they were working with. Thomas Edison was so horrified of what happened to his worker Clarence Dally [wikipedia.org] due to radiation poisoning that he abandoned any further research with X-rays. Not to mention Marie Curie death due to exposure to radiation and countless others that worked in her field.

      Back then of course people thought drinking radium was a good health product and that shoe sales man could operate their x-ray on a casual basis to fit shoes giving them more REM exposure in a day than a modern nuclear power plant worker is allowed a year.

      I'm not saying that WiFi is dangerous, but as a precedent people have often generally underestimated some dangers with emerging technologies and we should never discount such a thing could happen. Of course we due scientific study than complete news worthy paranoia.
      • Re: (Score:3, Insightful)

        by rasputin465 (1032646)
        I'm not saying that WiFi is dangerous, but as a precedent people have often generally underestimated some dangers with emerging technologies and we should never discount such a thing could happen.

        Yes, but radio waves are not an emerging technology. After about 120 years of study, I think we can safely say that radio waves are the best-understood part of the EM spectrum, in terms of the physics of their interactions.
  • Eek! (Score:5, Funny)

    by mibalzonya (1072126) on Tuesday May 22, 2007 @08:43AM (#19220407)
    I suggest aluminum foil hats.
    • Re:Eek! (Score:4, Interesting)

      by Yetihehe (971185) on Tuesday May 22, 2007 @08:48AM (#19220481)
      I suggest not. Some tinfoil hat designs can actually increase your exposure to radio waves [popsci.com].
    • Re: (Score:3, Informative)

      by Xest (935314) *
      You obviously didn't see the program, one person in it complaining wifi gives her headaches had covered her entire room in tin foil to protect her from it all :p
      • Re:Eek! (Score:5, Insightful)

        by CastrTroy (595695) on Tuesday May 22, 2007 @09:03AM (#19220735) Homepage
        I see lots of complaints of this. People who are extra sensitive to electronics and such. I would like to submit these people to a double blind study so that we can prove (or disprove) the effects are real, and not people who just have something else wrong with them that makes them feel more tired, or have headaches, or unable to concentrate, or whatever other symptoms they have. It seems to me like there's a lot of anecdotal evidence, but that there isn't any real studies being done.
        • Re:Eek! (Score:5, Interesting)

          by Xest (935314) * on Tuesday May 22, 2007 @09:17AM (#19220963)
          Well again, on the show they said the woman in question was able to tell when wifi was on or off 2/3rds of the time in tests, 66% isn't really a high enough chance for me to believe hers is a real known problem, particularly when they didn't explain her testing methodology, if they only ran 3 tests for example then get 2 out of 3 right is in the correct range of a 50% chance of getting it right by mere guessing should she have got a 4th test wrong.

          They did however mention that Sweden recognises electro-sensitivity as an official disability so there is perhaps some credibility in the whole idea, how much is still questionable of course.
          • Re: (Score:3, Informative)

            by justasecond (789358)

            They did however mention that Sweden recognises electro-sensitivity as an official disability

            The show's out of date then. There was a WSJ article last week or the week before that specifically discussed Sweden kicking so-called electro-sensitive people off disability.

        • Re: (Score:3, Funny)

          by R2.0 (532027)
          Wow - that explains so much. I have been plagued for years with an eerie knowledge of when my TV is on, even with no signal. It manifests itself as a high pitched noise that only I can hear, and I can tell with 100% accuracy when the TV is on or off.

          I never thought of it as a disability, though - I just thought it was an older model and the electronics were giving off a hum, and I just haven't lost my high frequency hearing yet. But now that I know there are others like me, we can form a support group an
        • Re:Eek! (Score:4, Informative)

          by metamatic (202216) on Tuesday May 22, 2007 @09:42AM (#19221399) Homepage Journal
          7 real studies have been done.

          The "electrosensitive" crackpots couldn't detect a mobile phone signal even after 50 minutes of continuous exposure.

          http://www.bmj.com/cgi/eletters/bmj.38765.519850.5 5v1 [bmj.com]

          It could be psychosomatic, it could be some other mental or physical illness, but it isn't EM radiation that's making them ill.
  • FUD (Score:4, Insightful)

    by Yetihehe (971185) on Tuesday May 22, 2007 @08:44AM (#19220415)
    Typical wifi - 100mW. 2g Cell tower - 20-100W. In cities they are using micro cells, which typically have about 3W power. There are experiments which show cell phones are a little dangerous, and there are scientist, who tried for years to show there is big danger, but found none and converted to "no harm" camp. So YMMV.
    • Re: (Score:2, Insightful)

      by adonoman (624929)
      What kind of scientist goes about trying to "prove" some hypothesis for a year? You don't decide what result you want first and then try and get data to show that you're right. You get the data, and then decide what that data is showing you. At least he was willing to change his opinion when the facts didn't support him (or her).

      It's "science" like that that is the source of most of these pseudo-science stories. The flat-earthers, and the circle-squarers, and the perpetual motion people all start out w
      • Re: (Score:3, Insightful)

        by TheRaven64 (641858)

        What kind of scientist goes about trying to "prove" some hypothesis for a year? You don't decide what result you want first and then try and get data to show that you're right. You get the data, and then decide what that data is showing you.

        The scientific method is:

        1. Observe.
        2. Hypothesise.
        3. Test.
        4. Repeat.

        Presumably this scientist was on phase 3; attempting to test his hypothesis. When they testing indicated that the hypothesis was false, he altered it to conform to the newer observations.

        • Re:FUD (Score:5, Insightful)

          by paeanblack (191171) on Tuesday May 22, 2007 @09:35AM (#19221285)
          he scientific method is:

                1. Observe.
                2. Hypothesise.
                3. Test.
                4. Repeat.

          Presumably this scientist was on phase 3; attempting to test his hypothesis. When they testing indicated that the hypothesis was false, he altered it to conform to the newer observations.


          Unfortunately life is not Star Trek. The pragmatic method is:

                1. Hypothesise.
                2. Beg.
                3. "Prove".
                4. Publish.

          Science costs money. Money comes from benefactors. Benefactors don't like surprises. You publish the results you were paid to discover, or you don't get more money. Welcome to the real world. Wear a helmet.
    • Re:FUD (Score:5, Insightful)

      by VeriTea (795384) on Tuesday May 22, 2007 @09:03AM (#19220751) Journal
      Output power doesn't tell the whole story, proximity is much more important. Electromagnetic power density dissipates at the inverse square of the distance from the emitter.

      All you have to do is consider the receive power. It is typical to receive a wifi signal at -65dBm, while a cell signal indoors is seldom stronger then -80dBm. Even if you consider multiple channels and multiple carriers on each cell tower, you would seldom get a composite power level greater then -70dBm indoors. -65dBm is approximately 3 times stronger then -70dBm. Of course these are typical levels, but when you consider how many wifi networks you usually pick up in your own home (esp. apartment), you will almost always receive a far greater exposure to electromagnetic radiation from wifi then from cell phone towers.

      Full disclosure: I perform power density theoretical studies and measurement levels for the wireless industry, and also design in-building wireless repeater systems so I have a fair bit of experience here.

    • Re: (Score:3, Informative)

      by mdsolar (1045926)
      So, your WIFI is 1 meter away and the cell tower is 1 kilometer away, which delivers more power where you are at. Take the cell tower number and divide by a million (1000^2) and you'll see that WIFI yields greater exposure. Doesn't mean there is a problem, but it is not just power level at the antenna that is important.
      --
      Fusion power from your roof: http://mdsolar.blogspot.com/2007/01/slashdot-user s -selling-solar.html [blogspot.com]
  • WiFi is microwaves (Score:5, Informative)

    by QuietLagoon (813062) on Tuesday May 22, 2007 @08:44AM (#19220423)
    Can skulls really 'absorb' EM radiation?

    802.11b/g uses 2.4GHz radio waves. That's the same frequency range as microwave ovens. Microwave ovens work because the microwaves are absorbed by the bonds in the water molecules of food (which is why dry food does not cook in microwave ovens).

    So yes, human tissue that contains water can absorb WiFi radiation. That is a fact.

    What is not known is: how much absorption of that radiation is bad for the kids?

    • by StarfishOne (756076) on Tuesday May 22, 2007 @08:48AM (#19220491)
      I've always wondered why these networks use 2.4GHz radio waves.

      I'm not a physicist, so really: is there an advantage to this frequency? Why not 1.2GHz.. or 3.6GHz, etc.? Why something so close to the frequency range of microwave ovens?

      If this is a really dumb question, I already ask for forgiveness. :)
      • by QuietLagoon (813062) on Tuesday May 22, 2007 @08:54AM (#19220577)
        802.11a uses the 5GHz range, out of the way of microwave ovens.

        2.4GHz was used because it was available for use, i.e., it would not interfere with frequencies already allocated to other services in the microwave area.

        In other words, the thought process (if you can call it that) was not, "let's find a frequency for 802.11b that is free of interference from other sources". It was more along the lines of, "let's find a frequency for 802.11b so that 802.11b won't mess up anything of import, i.e., microwave ovens don't really care about interference from your wireless router.

        By the way, the same "thought" process was used to pick a frequency for the 2.4GHx wireless phones.

        • by Shakrai (717556)

          n other words, the thought process (if you can call it that) was not, "let's find a frequency for 802.11b that is free of interference from other sources". It was more along the lines of, "let's find a frequency for 802.11b so that 802.11b won't mess up anything of impor

          I'm pretty sure that "Let's find a frequency that's unlicensed so we can legally use it" was part of the thought process too.......

      • by Shakrai (717556) on Tuesday May 22, 2007 @08:54AM (#19220585) Journal

        I've always wondered why these networks use 2.4GHz radio waves.

        I think it mainly had to do with the fact that the same part of 2.4GHz is open for unlicensed use globally. The other unlicensed ISM (industrial-scientific-medical) bands in the United States are used for other stuff in other nations. The easiest example is 900mhz. Part of it is available for unlicensed use in the United States. But as anybody with a quad-band GSM phone knows, that's a cellular band in most of the rest of the world.

      • by jasen666 (88727)
        I don't believe there is a scientific reason for it. I think this was just the range that the FCC allocated as usable for this purpose (and other purposes).
        This band, plus the ISM 5Ghz band.
      • Ah, that explains things quite a bit. Thank you for the fast replies! :)
      • by LarsG (31008)
        Why 2.4GHz? Because it one of very few frequency bands that are internationally available for unlicensed use. Which is also the reason why microwave ovens, some cordless phones, bluetooth and lots of other stuff use it.

        http://en.wikipedia.org/wiki/ISM_band [wikipedia.org]

      • by Andy Dodd (701) <atd7&cornell,edu> on Tuesday May 22, 2007 @09:16AM (#19220951) Homepage
        I believe there is a scientific reason for the ISM band being there - I think water has a bit of an absorption peak in the 2.4 GHz region.

        For this reason, 2.4 GHz wasn't too hot for long-haul communications due to water vapor in the air, so no one was in a rush to license spectrum for it, and no one fought designating it as an "Industrial, Scientific, Medical" band. (with the primary use in all three of those categories being to take advantage of that water absorption peak for heating.) Now, because the band is such a cesspool, no one minded allowing low-power unlicensed communications in that band.

        Now, as to the health effects of this - Yes, the water in your body is more likely to absorb 2.4 GHz RF. No, that absorption will not do any cumulative damage. Absorbing 2.4 GHz RF will make the water molecules in your body vibrate a little more (i.e. it will heat you up.) At high powers, this does become dangerous as the heat basically cooks you from the inside (just like a microwave oven). At low powers (with 802.11 being a great example), the body is able to safely dissipate the heat rapidly enough so that not only is no damage done, the change in temperature at any point in the body is negligible. You're more likely to get burned by touching the heatsink of the RF amp than you are by touching a circuit trace carrying RF at those power levels.

        RF radiation is nothing like nuclear radiation - the critical difference is that nuclear radiation is ionizing, that is to say that it can not only vibrate molecules a bit, but it has enough energy to alter them. This has the effect of "flipping bits" in your DNA and other such nasty stuff. Since "bit flipping" can have cumulative effects, low levels of ionizing radiation can be dangerous in the long term, because the damage accumulates. With RF, it doesn't unless power levels are so high as to induce temperatures that cause thermal damage.

        Prior to graduate school, I worked at a company that built RF power amplifiers for cell towers (30-45W average power output), and many of my coworkers had been working with microwave RF amps since the very first cell system Motorola deployed. (Yes, we had some ex-Motorola old hands there, who had interesting stories from the early days when the system designers were also heavily involved with the installation process of new base stations.) No health problems whatsoever.

        Since graduate school, one of the tasks of my department is taking equipment through EMI testing. We're frequently right at OSHA RF exposure limits - no health problems with any of us (Well, at least no new ones that weren't preexisting conditions), even our mentor who has been doing this for 20-30 years.
    • by CastrTroy (595695)
      That's the same frequency as many cordless phones. How many people spend hours with one of those things right up against the side of their head. Why isn't anybody complaining about those. As far as I remember from my physics classes electromagnetic waves lose power as a square of the distance. And since my cordless phone and wifi network have similar range, they must use the waves of the same strength. So, I must say that if we're going to be worried about wifi, that we should all throw out our cordles
    • by morgan_greywolf (835522) * on Tuesday May 22, 2007 @09:06AM (#19220787) Homepage Journal
      Typical 802.11b/g = 1 mW - 100mW
      Typical microwave oven = 750W-1500W (750,000 - 1,500,000 mW)

      Big difference.
      • Re: (Score:3, Informative)

        by Moby Cock (771358)
        And the oven is a resonant cavity. Huge difference.
      • Re: (Score:3, Informative)

        by amper (33785) *
        First of all, just because a microwave oven dissipates 1500 W of power, that doesn't mean that it actually *radiates* 1500 W of power. Second of all, the FCC has guidelines for microwave oven emissions. Total leakage at the time of manufacture is limited to 1 mW/ cm^2, and 5 mW/ cm^2 over the lifetime of the unit. This generally falls into the acceptable ANSI/IEEE C95.1-1992 guidelines for exposure, given that microwave oven usage is generally intermittent.
    • by Rocketship Underpant (804162) on Tuesday May 22, 2007 @09:43AM (#19221423)
      Guess what:

      1. Your body absorbs EM radiation from the infra-red band! Also known as heat, IR sources are everywhere and can eliminate the need for you to wear thick clothing.

      2. Your skin absorbs EM radiation from the optical spectrum! Black people are particularly vulnerable to this type of radiation absorption.

      3. Your skin absorbs radiation from the UV spectrum! Millions of people develop tans and synthesize vitamin D every year due to UV radiation absorption.

      Notice that in all these cases, we're talking about the conversion of energy to *heat* by the absorbing tissue. Raising an alarm about this is like getting up in arms about the dangers of "dihydrogen monoxide". In fact, radio-band emissions are even lower-energy than the energy spectra listed above, and is thus generally even more benign.

      Dangerous radiation is high-energy ionizing radiation, like that found in the X-ray and gamma spectra. Such radiation has the capacity to damage cell DNA and cause radiation sickness, but that's a completely different animal than what this article is dealing with.

    • Re: (Score:3, Insightful)

      by profplump (309017)
      There's a whole range of microwave frequencies that are absorbed by water molecules. We picked ~2.4 GHz for home appliances because it offers a good balance of penetration vs. absorption and because it's relatively cheap to produce and to shield. But water absorbs radiation at other wavelengths as well; IIRC 900 nm and 1200 nm are absorption peaks, and there's a whole range of other wavelengths with varying degrees of absorption. We did choose 2.4 GHz for WiFi just because it's unlicensed, but we didn't cho
  • so... (Score:2, Funny)

    by cosmocain (1060326)

    'The radiation Wi-Fi emits is similar to that from mobile phone masts ... children's skulls are thinner and still forming and tests have shown they absorb more radiation than adults'.
    it absorbs? wowy! so i gotta keep children away to avoid serious wifi-connection-troubles. damned, those little buggers seem to interfere with almost anything!
  • So... (Score:2, Funny)

    by Chysn (898420)
    So... the news is that there's alarmism?

    Thanks. I'll be sure to watch out for it.
  • Gah! Won't someone think of the children!?

    If we use 802.11, the terrorists win.

    I'm sure it's worth study, and I personally think WiFi is used too much. I'm not saying we shouldn't use it a lot, but I know some homes and businesses that might just be better off with some CAT cables. I mean, if all of your computers in your 1 bed apartment are desktops, why go WiFi?
  • And in other news from the BBC http://news.bbc.co.uk/2/hi/technology/6676129.stm [bbc.co.uk]
  • by 2008 (900939) on Tuesday May 22, 2007 @08:45AM (#19220445) Journal
    Of course they can. Everything does. Notice how when you put your head near a source of radiant heat it feels warm?

    "Do not look into laser with remaining eye" is also appropriate here...

  • by swschrad (312009) on Tuesday May 22, 2007 @08:46AM (#19220455) Homepage Journal
    not a pretty sight, is it?

    the FCC has specifications of radiation density versus frequency that are limits in their rulebooks, limits used to isolate access to radio facilities from microwaves to commercial broadcasters... to ham radio operators burning electrons in the basement. these have been codified by medical research. if you're going for an advanced ham license, you have to study the milliwatts per meter limits, the question occasionally comes up on the test.

    so there are 3/4 million americans who know this, not just ten academics in the tower.

    where the hell did this whining of Luddites come from, and why wasn't it left there?
  • by supersnail (106701) on Tuesday May 22, 2007 @08:47AM (#19220473)
    Here [theregister.co.uk]

    Basicaly in the old country they have a government official who is unprepared to admit radio waves, mobile phones etc, are safe; no matter what the evidence.

     
  • by quibbler (175041) on Tuesday May 22, 2007 @08:47AM (#19220479)
    Mobile phone towers are many, many times more total output. Yes, both transmit in the microwave spectrum, but the 'notch' in the microwave spectrum that resonates water (and thereby heats your food, cooks your brain) is extremely tight (2.45 Ghz). If you're above it or below it, the water molecules in your body (or food) simply won't vibrate/resonate and there's no heating. And yeah, people use 'radiation' all the time to invoke the panic of ionizing nuclear radiation (bad) with electromagnetic radiation (mostly harmless). (Meanwhile these same people go suntan in the name of health, basking in the glow of an unshielded fusion reactor. Yay humanity.) ...People who live by the sword get shot by those who dont.
    • by Ellis D. Tripp (755736) on Tuesday May 22, 2007 @09:07AM (#19220813) Homepage
      The operating frequency of microwave ovens was chosen to be in an unlicensed (ISM) frequency band, that would provide good penetration into foods, and lent itself to the mass production of inexpensive magnetron tubes.

      The lowest resonant frequency for a water molecule is 22.235 GHz, or nearly 10X the operating frequency of a microwave oven.
    • by littleghoti (637230) on Tuesday May 22, 2007 @09:15AM (#19220931) Journal
      Actually, 2.45 GHz isn't the maximum of the absorbance for microwaves. If it was, all the energy would be dumped at the surface of food, and there would be virtually no penetration. Water absorbs over a broad spectral range, at least in the liquid phase, where quantised rotational bands can be ignored.

      And what you say about the different energies of radiation is mostly true, although EM radiation covers a range that includes UV, x-rays and gamma radiation, which are not very good for you.
      • I did a little research while I was in college for using focused microwaves to create a "hot spot" in high speed flow and I found that water responds really really well in the 800MHz to 1 GHz microwave frequency range. You'd get the most rotation of the molecule on the rising edge of the wave at those frequencies (rotates back on the falling edge), hence the maximum friction between the molecules and maximum heat. Higher than that and the water doesn't have enough time to move before the wave is past it.
    • Re: (Score:3, Informative)

      by Fantastic Lad (198284)
      Why do people constantly focus on ionization as the problem?

      Brain cells respond to EM in ways inherent in biological design. EM has been demonstrated to have all manner of effects upon the human body and nervous system. Acupuncture is one of the more obvious ones; (metal needle inserted and set to rotating cuts through the Earth's magnetic field and 'injects' a current into the patient. This affects how cells function. Pain responses can be turned off.)

      Basically EM in a random noise makes the brain fuzz
  • Website story (Score:4, Insightful)

    by dylan_- (1661) on Tuesday May 22, 2007 @08:48AM (#19220485) Homepage
    The BBC website has a Wi-fi health fears are 'unproven' [bbc.co.uk] story which addresses this. My favourite quote, from Professor Will J Stewart:

    "This is not to say that all electromagnetic radiation is necessarily harmless - sunlight, for example, poses a significant cancer risk; so if you are using your laptop on the beach make sure and get some shade."
  • by Xest (935314) * on Tuesday May 22, 2007 @08:50AM (#19220523)
    Frankly the BBC was irresponsible in showing this episode of Panorama. I'm against censorship, but informational programs produced by a tax-payer funded media outlet should not be spouting such paranoid, biased crap as Panorama did last night.

    This is arguably the worst case of the BBC scrambling for ratings I've ever witnessed. Never before have I seen them stoop so low to try and raise viewing figures. I was sat watching it waiting for the part where they offer the opposing view of the situation to allow people to make their own minds up, unfortunately however, that never came - it was one sided anti-wifi propaganda all the way through, from start to finish.

    About the only attempt at offering an opposing view was the brief mention that the WHO states that there is no known risk of wifi at this time, this brief mentioning was followed by a couple of minutes of slagging off the credibility of the WHO.

    I'm no expert when it comes to wifi, radiation and so forth and I'm not claiming that wifi is 100% safe - it may well pose risks. The problem with the program however seemed to be that it's entire argument is based on the premise that there is some other danger to human health from radiation other than the heating effect, and from what I've read elsewhere, there is absolutely no evidence that there is any effect other than the heating effect. I'm sure those with better scientific knowledge may be able to correct me on this if I'm wrong, but if it's true as has been reported by other news outlets (and in fact even by the BBC themselves online) then the majority of the program was fundamentally flawed in it's arguments.

    What bothers me most is that we've gone from one lazy teacher looking for an excuse to get time off work claiming that wifi gives him headaches to a national wifi scandal. The worst part is that most reports that refer to the teacher in question who sparked this row ignore the fact that in scientific tests the teacher could neither a) tell whether wifi was on or off and b) now claims he gets these headaches wherever he is, even when not around wifi!

    If Wifi does indeed pose a threat then I agree we need to do something, but thus far this seems equivalent to the whole terrorism/think of the children/drugs/computer games make people kill FUD.
    • Re: (Score:3, Insightful)

      by jrumney (197329)

      Frankly the BBC was irresponsible in showing this episode of Panorama. I'm against censorship, but informational programs produced by a tax-payer funded media outlet should not be spouting such paranoid, biased crap as Panorama did last night.

      What I find most disturbing, is that they are probably helping the Scientologists make their case against last week's Panorama by following it up with this tripe.

    • Re: (Score:3, Informative)

      by anticypher (48312)
      This has been the way of the BBC for as long as anyone can remember.

      There are two sides to every story. Exactly TWO. Two diametrically opposed sides. Never a third. Never just one. Always TWO. No shades of grey permitted. No announcing a discovery without finding a skeptic to denounce it.

      If 99 scientists were to state that the sky is blue, the BBC would go out of their way to find some crackpot to claim the sky is actually red. And then give the two sides equal standing.

      Worse, Panorama has never been held u
  • Leukaemia (Score:5, Interesting)

    by weliwarmer (569280) on Tuesday May 22, 2007 @08:50AM (#19220525) Homepage
    My son was diagnosed with leukaemia (AML15 for those interested) on his 1st birthday. My first trip home from the hospital I turned of the wireless router, cordless phones and my mobile/cell. He's now 3, built like an ox and hopefully fixed for good.

    My neighbours all have wireless, cordless and mobiles so I eventually turned all mine back on. Two years on and no-one else in the house, including my 2 other boys, have cancer.

    Who knows what caused it. Live life to the full, make the kids smile and if low power wireless gadgets worry you, please get out more.
  • by Applekid (993327) on Tuesday May 22, 2007 @08:51AM (#19220529)
    So if WiFi can give you cancer, what can a bunch of loose network cables strewn on the floor give you?

    It's not the flight I'm afraid of, it's the notebook's landing that's the dealbreaker.
  • It's odd how the blame essentially everything on Wi-Fi. If only someone would invent a pill that helps the body cope with radiation (like potassium iodide, but for wi-fi) and then sell it to the UK health service at a tremendous markup! Then the children would be safe.

    We can even make scary sounding slogans to remind people to take their pills. "Why die for wi-fi? Take PlaceboXL and live!"
  • Come on, this is obvious.

    Radio waves are harmful. We know this. There is no cut-off point at which they suddenly go from harmless to harmful.

    However...

    We've been living with this stuff for years, and we're not noticably dropping dead in any way related to it. It's in the noise compared to all the other bad things in our lives.

    This is approximately item #6589726 on our list of killers. Relax. Have a cigarette.
  • Of course, it doesn't seem overly healthy to me to put any kind of artificial radiation source near your body. But frankly, I think our health is being heart a great deal more by pollution, GMO foods, and the excess of allergens in our diet from things like soy, corn, dairy, and wheat.
  • This is garbage (probaly...see below). Wi-Fi frequencies are in thr non-ionizing range, and as such will not cause any tissue mutations or changes. The radiation is absorbed by tissues (usually by the water therein) and creates heat -- this is how a microwave oven works. However, unlike an oven, the world is not a resonant cavity so the energy dissipates very quickly and poses no threat other than a heating/cooling cycle.

    In the ionizing range the high energy radiation actually punches out nuclear part
  • by Flying pig (925874) on Tuesday May 22, 2007 @09:13AM (#19220903)
    After re-reading Richard Feynman's lecture on Cargo Cult Science. With its demolition of "experiments" without controls, and how people kept on doing pointless lab rat experiments after the methodology was debunked, it's a sad saga - which is just as true today after so much "progress".

    Unfortunately, in the UK at least, the number of scientifically trained journalists can probably be counted on one of Ben Goldacre's fingers.

    Interesting that none of the phone mast posts seem to have remembered the inverse square law - sorry if you did and I missed you - which mean that radiation levels at the ground are a tiny fraction of what you get from the phone. And that nobody has mentioned all the radiation we used to get from TV and radio sets. As I recall, the radiation you get from an old tube superhet set (from the IF) is much more intense than the radiation from WiFi. It is lower frequency, but then the skin effect is less, and as anybody who ever played about with NMR will recall, VHF does things to organic molecules.

    We'd better take action now. Let's get rid of all that nasty radioactivity - oops, Madam, there goes your granite kitchen work surfaces and your low-sodium salt. And all the radiation sources beginning with the most intense. So we've now turned off the Sun, mobile phones, radio, TV, electrical generating. We can't use coal (have you looked at what you get in the ash). So we can just sit in the dark and freeze.

    As for the leukaemia cases - I have long believed that a far more convincing explanation is exposure to farm chemicals, pesticides, and the new virus and bacterial strains resulting from population movement. It is possible that farming overspray with chemicals which have been subsequently banned is a more probable cause of leukaemia clusters than, say, living near a rural electrical supply line. In the UK, and probably in the US too, the parts of Government which deal with farming tend to be extremely secretive and their decisions are often hard to understand. To my mind, they are far more likely to suppress information about such things than the relatively open parts of Government which deal with non-farming health and safety.

  • by cerberusss (660701) on Tuesday May 22, 2007 @09:20AM (#19221013) Homepage Journal
    I've got two WiFi base stations. The minute I enter my house, I get a headache!

    Strange, isn't it?

    What's even stranger is that it only started when my girlfriend moved in with me.
  • Climate Science? (Score:3, Insightful)

    by einer (459199) on Tuesday May 22, 2007 @09:25AM (#19221083) Journal
    Does this remind anyone of the current climate science "debate" where every single reputable phD feels strongly that humans are impacting the environment yet the shrillest and loudest of an incredibly small dissenting crowd (that happens to have powerful motives) are picked to broadcast their ignorance to the masses via the media?

    Oh well. We might as well fold on this too, just like we'll fold on global warming and "democracy", let alone human rights. How can this not fail? It is in the conservative powers perceived best interest to make open communication and a free competative marketplace of ideas go away. It can only take power from the government. It will never empower the leaders.

If it happens once, it's a bug. If it happens twice, it's a feature. If it happens more than twice, it's a design philosophy.

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