Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Friday, November 9, 2012

Sense, nonsense, and microwaves

One of the difficulties in detecting spurious claims occurs when the writer (or speaker) mixes fact, and real science, in with spurious bits and stirs the resulting hash so thoroughly that it's hard to tell which is which.  When a claim is made of unadulterated bullshit (such as yesterday's post about ley lines), our job is easier.  Mixtures of science and pseudoscience, though, are often hard to tease apart.

I saw a good example of this yesterday, in an article on the website NaturalSociety called "Microwave Dangers - Why You Should Not Use A Microwave."  In this piece, author Mike Barrett describes the terrible things that microwave ovens do to the people who use them and to the food that's cooked in them.  Amongst the claims Barrett makes:
  1. Microwave ovens heat food by making water molecules move "at an incredible speed."  This differs from conventional ovens, which gradually transfer heat into the food "by convection."  Further, this energy transfer into the water molecules results in their being "torn apart and vigorously deformed."
  2. Microwaves are radiation.  This radiation can "cause physical alterations" even though microwaves are classified as "non-ionizing."  This radiation "accumulates over time and never goes away."
  3. Microwave exposure has a greater effect on your brain than on your other body parts, because "microwave frequencies are very similar to the frequencies of your brain," and this causes "resonance."
  4. Exposure to microwaves causes all sorts of problems, from cancer to cataracts and everything in between.
  5. Raw foods have "life energy" in the form of "biophotons," that came directly from the sun.  These "biophotons" contain "bio-information," which is why eating sun-ripened raw fruits makes you feel happy.  Microwaving food destroys the "biophotons" which makes it lose all of its nutritional value.
  6. Microwaving foods causes the conversion of many organic molecules into carcinogens.
  7. Microwave ovens were invented by the Nazis.
Okay, let's look at these claims one at a time.
  1. First, all heating of food makes the molecules move faster.  That's what an increase in temperature means.  A piece of broccoli heated to 60 C in a microwave and a piece of broccoli heated to 60 C in a steamer have equal average molecular speeds.  Ordinary ovens don't heat most foods by convection; convection heating requires bits of the food itself to move -- so, for example, heating a pot of soup on the stove creates convection, where the bottom part of the soup, in contact with the base of the pot, gets heated first, then rises, carrying its heat energy with it.  Foods in conventional ovens are heated by a combination of radiation from the heating coils, and conduction of that heat energy into the food from the outside in.  Further, heating the water molecules doesn't "tear them apart," because then you'd have hydrogen and oxygen gas, not water.
  2. Microwaves are radiation.  So is sunlight.  Sure, microwaves can cause physical alterations, which is why it's inadvisable to climb inside a microwave oven and turn it on.  But not all kinds of radiation accumulate; the microwaves themselves are gone within a millisecond (absorbed and converted into heat) of when the magneto shuts off, otherwise it wouldn't be safe to open the door.  Barrett seems to be making an unfortunately common error, which is to confuse radiation with radioactivity.  Radioactive substances, or at least some of them, do bioaccumulate, which is why strontium-90 showed up in cows' milk following the Chernobyl disaster.  But your microwaved bowl of clam chowder is not radioactive, it's just hot.
  3. When oscillations of one body trigger oscillations of another body at the same frequency, this is called resonance.  However, your brain does not oscillate at the frequency as microwaves -- the frequency he quotes for microwaves inside a microwave oven is 2,450 megahertz (2.45 billion times per second), which is actually correct.  Brains, on the other hand, don't oscillate at all, unless you happen to be at a Metallica concert.
  4. Agreed, exposure to microwaves isn't good for you.  Thus my suggestion in (2) above not to get inside a microwave oven and turn it on.
  5. There is no such thing as a "biophoton."  You do not absorb useful energy in the form of photons in any case, for the very good reason that you are not a plant.  The only "bio-information" we have is our DNA.  Sun-ripened fruit may taste better, as it's ripened more slowly and has a longer time to develop sugars and esters (the compounds that give fruits their characteristic smell and taste), but microwaves don't destroy "life energy."  This bit is complete nonsense.
  6. Microwaving food may cause some small-scale alterations of organic molecules into carcinogens, but so does all cooking.  In fact, the prize for the highest introduction of carcinogens into food has to be awarded to grilling -- the blackened bits on a charcoal-grilled t-bone steak contain polycyclic aromatic hydrocarbons, which are known carcinogens.  The problem is, they're also very tasty carcinogens, which is why I still like grilled steaks.
  7. Microwave ovens weren't invented by the Nazis.  The first microwave oven was built by Percy Spencer, an engineer from Maine, in 1945.  The mention of the Nazis seemed only to be thrown in there to give the argument a nice sauce of evil ("anything the Nazis invented must be bad").  But it's false in any case, so there you are.
So, anyhow, that's my analysis of Barrett's anti-microwave screed.  He's pretty canny, the way he scatters in actual facts and correct science with poorly-understood science, pseudoscience, and outright nonsense; the difficulty is, you have to have a pretty good background in science to tell which is which.  All of which argues for better science education, and better education in critical thinking skills.  But any effort I make in that direction will have to wait, because my coffee's getting cold, and I need to go nuke it for a couple of seconds.

2 comments:

  1. Excellent post. I enjoy demystifying the longstanding misconceptions about "nuking" food in a microwave. Far too many people take that literally, believing that if they took their microwave apart, they would find that glowing green rod they've seen Homer Simpson fumbling around with at the start of every Simpson's episode.

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  2. Glad you wrote a response. That article is a load of fear mongering BS!

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