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Crossposted at Politicook.net

We have discussed stuff through around 2.8 meters.  That is the wavelength that would correspond to the height of a giant person, almost nine feet tall.  The next band blends in seamlessly, and I will discuss it presently.

Please remember that there is not any "hard" barrier from one wavelength to another, except our perception visually to see an extremely small portion of the spectrum.  As the crowd went crazy, Tommy shouted out "Here we go!"  He left the "after the jump part out, but that is OK.

Once wavelengths at this range are reached, transmission properties are even more in line of sight and not ionospheric reflection.  Now we consider wavelengths lower than the sort of arbitrary 2.8 meters to those of around 1 millimeter or so.  Some use other limits, but in general this is not a bad description.

Microwaves are generated differently than classical radio waves, not with oscillators made from "traditional" components, but rather ones that have more to do with geometry and the interaction of alternating electric fields with cavities, (like the Magnetron in your microwave oven) or other, nonlinear effects.  Since I am not an electronics engineer, I will not provide an inadequate discussion of their generation.  Rather, I will provide a discussion of a few of their impacts.

Before I continue, I should explain the energy bands in matter (not to be confused with energy bands as used in semiconductor work).  There are four basic motions in matter:  translational (going from points A to B in more or less a straight line); rotational, where molecules or parts of them spin around on some axis; vibrational, wherein atoms within molecules move to and fro, but no bonds are broken; electronic, where electrons are promoted or demoted into higher or lower energy levels; internal nuclear transitions, where the internal arrangement of nuclei changes.

Except for translational energy, which has to the with the thermodynamic temperature of the environment for the most part, (there are important exceptions, but mostly it is that), each transition is associated with a particular wavelength of electromagnetic energy.  For instance, water molecules will spin on the axis described by the line that divides the molecule into two symmetrical halves.  It turns out that the rate of rotation is quantized, that is, there are only a few allowed angular velocities for such rotations.

My microwave oven, like most, is a broadband microwave transmitter with a nominal frequency of 2.45 GHz (gigahertz) has a nominal wavelength of 122 mm.  That is about right to make water molecules rotate and bump into each other.  When they bump into each other, some the rotational energy is turned into translational energy, which makes the mass of foot heat.  It turns out that sugars and fats also have some parts of their molecules that are stimulated to rotational excited states by this radiation, and they heat up as well.  The reason that fats and sugars seem to heat up more rapidly has to do with another physical property, heat capacity.  It takes more heat to raise the temperature of water than any other substance, so fats and sugars have a faster temperature rise because it takes less energy to heat them.

Interestingly, my cordless telephone operates at 2.4 GHz (125 mm), very close to that of my microwave oven.  Why does it not heat up my brain when I use it?  Likely it does, but my oven outputs 1.10 kw (kilowatts) while my telephone only a few mw (milliwatts) at maximum, a factor of over a million in difference.  Still, I wonder.

Other uses for microwaves are radar (used for lots of things).  Interestingly, the folks who developed radar for military use, after the war, started the Amana Company.  One of the engineers noticed that the chocolate candy bar in his pocket melted whilst he was working near the main transmitter tube.  Remember what I said about fats and sugars getting hotter, faster?  The Radarange was the first commercial microwave oven, offered by Amana decades ago.

For communications, microwaves act in a similar manner to radio waves in that they are modulated by impressing a signal onto a carrier and decoding the matrix at the receiver.  The bells and whistles are different, but the basic ideas are the same as long as we do not consider the dreaded digital signals.  Let us crawl before we try to sprint, however, but we will look at the differences at another time.

There has been speculation about a relationship between the use of cellular telephones and brain cancer.  With the discussion before about heating by induction of rotation, it is a valid question.  Studies are inconsistent, and I certainly do not have a good answer.  I will, however, make these observations without comment.

I have personally known two people who have died of brain cancer, and both of them kept a cell phone on the side of their head for years and years.  Then there is the case of Johnnie Cochran, who lived with one.  This is speculation, but I strongly suspect that Senator Kennedy used one extensively as well.  Does that prove anything?  No.  It does make me to consider seriously hooking up my old corded telephone for common use.  Will I completely quit using the cell or the cordless.  No.  But common sense says to minimize risk.

Perhaps it is a good idea to keep the telephone on the belt or in the purse and run wires for earbuds and a microphone.  I am not saying this on any authority, but I have begun to discourage my boys and Mrs. Translator from talking directly into a cellular telephone.  The main difference between home cordless and cellular telephones is that home cordless ones use a much lower power level than cellular ones.  For a home cordless, we are talking a couple of hundred feet of range.  For cellular, sometimes miles of range to the nearest tower.  Remember, all electromagnetic radiation follows an inverse square intensity relationship, to to double the range, you have to quadruple the energy.  I will stick around a while for questions, comments, and flames.  Warmest regards, Doc.

Originally posted to Translator on Fri May 30, 2008 at 07:57 PM PDT.

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Comment Preferences

  •  Good advice. Thanks. (6+ / 0-)

    Auntie Em: Hate you. Hate Kansas. Taking the dog. Dorothy

    by haremoor on Fri May 30, 2008 at 08:01:42 PM PDT

  •  Good evening, Doc. (5+ / 0-)

    I definitely have to bookmark this diary -- my eyes were swimming, three sentences in.

    Interesting to see that you are now a celebrity -- can't remember what idiot did a whole diary airing some grievance against you, but I had to laugh.  Rest assured, you were completely and thoroughly defended.

    Cheers.

    My faith in the Constitution is whole, it is complete, it is total. Barbara Jordan 1974

    by gchaucer2 on Fri May 30, 2008 at 08:07:33 PM PDT

    •  Thank you very much. I appreciate (5+ / 0-)

      your kind words and defense.  One of the reasons that I hand around after posting is to clarify things that I have stated that others might not understand, not because of lack of education, but by having a different perspective.  You may be assured that I usually learn more from questions than I do from preaching.  Warmest regards, Doc.

      Sometimes I feel like Robert Louis Stevenson created me. -6.25, -6.05

      by Translator on Fri May 30, 2008 at 08:10:49 PM PDT

      [ Parent ]

  •  Your diaries are great, Doc. I look fwd to them! (3+ / 0-)

    It's so refreshing to read real science, finally, again.

    Coast-to-Coast Pizza-Arugula-Keilbasa Run for Obama! - *Here* - http://www.dailykos.com/story/2008/5/5/155525/0947

    by Blue Waters Run Deep on Fri May 30, 2008 at 08:11:28 PM PDT

  •  Inverse square law (6+ / 0-)

    Think of that when you use your cell phone.

    While there is not incontrovertible proof that the low levels of microwave radiation from cellphones can result in cellular disruption, you can still use you phone safely .. use a headset, or operate the cellphone in 'speakerphone' mode and get it away from your head.

    "If you want to go quickly, go alone. If you want to go far, go together." We need to go far, quickly.

    by shpilk on Fri May 30, 2008 at 08:15:57 PM PDT

    •  I agree completely. (4+ / 0-)
      Recommended by:
      shpilk, Urizen, trashablanca, earicicle

      Just because it is nonionizing, that does not necessarily mean that it is harmless.  Here is a thought experiment.

      Rays from a campfire are very rich in the infrared, nonionizing, low in visible, pretty much nonionizing, and very poor in the ionizing ultraviolet.  Take you hand and put it beside campfire coals for a couple of hours.  I guarantee that you will be injured, but not ionized.

      You make an excellent point.  Thank you.  Warmest regards, Doc.

      Sometimes I feel like Robert Louis Stevenson created me. -6.25, -6.05

      by Translator on Fri May 30, 2008 at 08:20:18 PM PDT

      [ Parent ]

  •  Caveat (1+ / 0-)
    Recommended by:
    Translator

    I think you'll find that microwave generators in the low power ranges, such as those for personal communications devices, use pretty much the same old fashioned oscillator techniques as lower frequency RF devices do.

    •  I do not disagree. As I said, I am (2+ / 0-)
      Recommended by:
      SherriG, earicicle

      not an electronic engineer, so did not want to pretend to be an expert where I am not.  I agree that my cordless telephone, operating at almost the same wavelength as my microwave oven, uses very different technology, but at 2.4 GHz we are getting close to different technology.

      I think that one reason for the difference between low and high power applications has to do with heat dissipation.  My microwave over has an input of 1.6 kw, and an output of 1.1 kw, so it has to disperse 500 w, where a cordless telephone has to disperse only a few mw. Your comment also pointed a typo out to me.  In the body I said that my oven had an output of 1.18 kw.  I looked again, and it is only 1.10 kw.  I will correct the text.  Thank you for getting me to thinking.  Warmest regards, Doc.

      Sometimes I feel like Robert Louis Stevenson created me. -6.25, -6.05

      by Translator on Fri May 30, 2008 at 08:38:32 PM PDT

      [ Parent ]

  •  Microwave ovens heat via dielectric heating (1+ / 0-)
    Recommended by:
    Translator

    Many people think that water molecules absorb the specific wavelength that a microwave oven generates.  In fact a microwave oven will heat any bipolar molecule.  Water just happens to be a very bipolar molecule and quite plentiful in our food.

    Check the Wikipedia.

    •  I do not desire to get into a war of semantics (0+ / 0-)

      with you, and will not.  The microwave region imparts rotational energy to molecules with a quantum transition consistent with the wavelength of the radiation bombarding it.  In the case of microwave radiation, some permanent magnetic dipole, must be present.  Sometimes that permanent dipole consists of only two centers of charge, sometimes many.

      I really am not familiar with the concept of a bipolar molecule, but the terminology is not inaccurate, just not often used.  I believe that we agree that the magnetic and electric fields, caused by charge separation due to atomic arrangement, is what causes microwave activity in molecules, or in molecular fragments.

      2.4 GHz will not cause it in all sensitive molecules, because the frequency does not necessarily correspond to a quantized transition.  Our microwave ovens are broadband, so there is a finite probability that an overtone or undertone resonant wavelength might excite any given molecule or molecular fragment.  Warmest regards, Doc.

      Sometimes I feel like Robert Louis Stevenson created me. -6.25, -6.05

      by Translator on Fri May 30, 2008 at 08:49:03 PM PDT

      [ Parent ]

      •  I guess I have to continue (1+ / 0-)
        Recommended by:
        side pocket

        Once things gain energy, the quantum levels, especially in a complex mixture like food, begin to merge into a continuum.  This is due to translational energy, that imparts a random energetic state to the target molecules or fragments.  As the quantized states begin to blur, everything gets some energy input.  Dr Colossus is correct, but it the reasons begin to impinge onto the macroscopic.  Warmest regards, Doc.

        Sometimes I feel like Robert Louis Stevenson created me. -6.25, -6.05

        by Translator on Fri May 30, 2008 at 08:54:17 PM PDT

        [ Parent ]

        •  I'm wasn't criticizing your diary (0+ / 0-)

          I thought the description of how microwaves heat was a little vague.  I once had a guy with a masters in physics tell me that microwave oven heat water because of the resonant frequency of water so I think it must be a common misconception, even amongst the science crowd.  I try to eliminate it when ever the topic comes up.

    •  Wikipedia ... (0+ / 0-)

      sigh. While it's true that any polar molecule will try to follow the field it is not necessarily true that the molecule will heat up the material it is a part of. That happens if the resonant modes also couple efficiently to absorption of energy. If not you will get elastic scattering instead.

      Good article, Translator. Too much science is left to the "clergy" (people with 3 letters after the name) when in fact we all need to know it. But one little clarification, if I may (Wikipedia makes the same mistake, BTW). Rotation is only a good quantum number in the gas phase. In liquids and some solids rotation is constrained and the corresponding term is libration (don't confuse that with the astronomical term of the same name), which is a rocking or rattling in a nearest neighbor cage. In crystals neither rotation nor vibration are good quantum numbers, the modes there are phonon modes, which are really coupled vibrations involving the whole crystal.

  •  in the title, do you mean "lambda"? (1+ / 0-)
    Recommended by:
    Translator

    if not, could you please explain what a lamba is?

    www.beyondmarriage.org

    by decafdyke on Fri May 30, 2008 at 08:50:20 PM PDT

  •  I use wired or bluetooth headsets for both (3+ / 0-)
    Recommended by:
    SherriG, Translator, earicicle

    cordless and cell phones.  Easier to mute and leaves both hands free for typing or driving.

    You're more likely to be injured by driving with one hand holding the cellphone to your ear which results in a fender bender or worse than getting brain cancer.

    •  I listen to The Who, The Moody (1+ / 0-)
      Recommended by:
      SherriG

      Blues, very Deep Purple, or King Crimson when I drive.  Warmest regards, Doc.

      Sometimes I feel like Robert Louis Stevenson created me. -6.25, -6.05

      by Translator on Fri May 30, 2008 at 09:34:10 PM PDT

      [ Parent ]

      •  I've Been (1+ / 0-)
        Recommended by:
        Translator

        fortunate enough to see the live performances of three out of the four bands that you listed.  We have great taste in music. :)

        "Nothing can stand in the way of the *power* of millions of voices calling for change" Obama

        by SherriG on Fri May 30, 2008 at 10:31:25 PM PDT

        [ Parent ]

        •  You are a person of interest. (1+ / 0-)
          Recommended by:
          earicicle

          For good music. Of course The Who are the best, but I still like  Blackmore's rifts.  Warmest regards, Doc.

          Sometimes I feel like Robert Louis Stevenson created me. -6.25, -6.05

          by Translator on Fri May 30, 2008 at 10:53:22 PM PDT

          [ Parent ]

          •  Ah Yes (2+ / 0-)
            Recommended by:
            pollwatch, earicicle

            the Who.  I saw them many years ago and they were outrageously good.  It was a very strange night though because the shipment of the sound equipment was delayed by over an hour.  Then, of course, it took another hour and a half to set up the vast wall of speakers, etc..but the full house was patient (perhaps aided by fragrant herbal distraction) and when the band finally took to the stage, they thanked us very much for waiting and proceeded to perform the entire Tommy opera.

            When I saw (very) Deep Purple, Uriah Heep was the opening act.  Another great show. Ian Pace is still one of my favorite drummers.

            Doc, you are a person of interest.  In fact, you are a person of very many interests.  I appreciate your voice, it is at once confident and humble.  I often read your diaries and I always recommend.

            "Nothing can stand in the way of the *power* of millions of voices calling for change" Obama

            by SherriG on Sat May 31, 2008 at 12:14:50 AM PDT

            [ Parent ]

  •  One has to ask themself (1+ / 0-)
    Recommended by:
    Translator

    Do you have more angular velocities than you did four years ago?

    It's the translational energy stupid.

  •  thank you for your diary (2+ / 0-)
    Recommended by:
    Translator, earicicle

    I don't have science background buthave great interest in physics took notes and learned;

    Former Fed Chairman Alan Greenspan is a "fraud" & the "J. Edgar Hoover of the financial world" & "biggest political hack in D.C." Sen. Harry Reid

    by pollwatch on Sat May 31, 2008 at 12:16:49 AM PDT

    •  I sometimes do not express things (0+ / 0-)

      very well, so anyone, especially you, are more than welcome to ask me to be more either specific or descriptive.  Warmest regards, Doc.

      Sometimes I feel like Robert Louis Stevenson created me. -6.25, -6.05

      by Translator on Sat May 31, 2008 at 12:31:07 AM PDT

      [ Parent ]

      •  if you (0+ / 0-)

        could elaborate:

        microwaves have more to do with geometry and the interaction of alternating electric fields with cavities

        Former Fed Chairman Alan Greenspan is a "fraud" & the "J. Edgar Hoover of the financial world" & "biggest political hack in D.C." Sen. Harry Reid

        by pollwatch on Sat May 31, 2008 at 03:38:41 AM PDT

        [ Parent ]

  •  Another point on phones (1+ / 0-)
    Recommended by:
    earicicle

    it is a good idea to have at least one phone that is not either cellular or remote.  Even without considering brain cancer, which is controversial, as you say, you can consider blackouts.

    In a blackout, cell phones may not work (in any disaster the networks get overloaded fast), and remote handset phones will not work, as there is no electricity.

    •  Not only a good idea... (1+ / 0-)
      Recommended by:
      plf515

      Absolutely essential! The good, old, curly-corded land line could be a lifesaver. We don't have reliable cell coverage in our remote location. So when the power goes out, the cordless phones are useless, and the humble corded phone is your best friend!

      Sweet are the uses of adversity...[Find] tongues in trees, books in the running brooks, Sermons in stones, and good in everything. -Shakespeare, As You Like It

      by earicicle on Sat May 31, 2008 at 07:17:18 AM PDT

      [ Parent ]

  •  Heavy duty science for us humble humanities (0+ / 0-)

    types, Doc, but fascinating nonetheless! ;-)

    Sweet are the uses of adversity...[Find] tongues in trees, books in the running brooks, Sermons in stones, and good in everything. -Shakespeare, As You Like It

    by earicicle on Sat May 31, 2008 at 07:19:09 AM PDT

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