Psychology of risk

Interesting article I just read, linked from Bruce Schneier’s blog (one of my favourite morning reads), about how irrational people are about judging and comparing risk. People often overestimate one risk, and underestimate another, and end up making poor choices.

An example from the article: after 9/11, people became irrationally afraid of flying. They cancelled flights, and drove their cars instead. As everybody knows (but somehow manage to ignore), driving is statistically much more dangerous than flying. Predictably, in a short period following 9/11, approximately 1000 more Americans died in car accidents than in the same period a year before.

I don’t imagine Bin Laden planned on that, but he can’t be too upset about it either.

The article’s comments on “radiation” mirror my own thoughts. People are always irrationally stressed out whenever the word “radiation” (fnord) appears.

When microwave ovens first appeared on the market, people were afraid of their “radiation”. I remember Radio Shack sold microwave leak detectors so you could “protect your family”. They probably don’t sell many of those these days. In the 80’s, it was high-voltage power lines and their “radiation”. Those fears subsided eventually. Today, there’s lots of misinformation, fear-mongering, and phobias about so-called cell-phone “radiation”. And, fairly recently, a bunch of clowns in the UK stirred up a silly shit-storm about WiFi networks in schools.

Sure these things all produce radiation, but radiation is not inherently dangerous. It’s not like the radiation from plutonium, or X-rays. These things are radiation only in the strictly literal/scientific sense of “that which radiates”… outward… from a point. What else radiates outward from a point? Light from a candle. Sound from your stereo speakers. Ripples from a pebble dropped in a pool of water. These are all radiation, in exactly the same sense that cell-phones or WiFi hot-spots produce radiation.

In fact, microwaves, power-line and cell-phone radiation are all exactly the same kind of radiation as ordinary light: electromagnetic radiation, composed of photons. The only difference between cell-phone radiation and light is the energy-level of the photons. The photons in cell-phone radiation are, in fact, of much, much lower energy than ordinary light photons.

It’s only when the energy reaches the levels of ultraviolet light that electromagnetic radiation becomes the dangerous “ionizing” kind. These are photons so energetic that they can penetrate the body, and destroy molecules (such as DNA) that they hit.

Every day, we are hammered relentlessly by ultraviolet light from the sun. Some day, it may give you skin cancer. But then, on the other hand, your body depends on that same UV light from the sun to make vitamin D. Can’t live with it, can’t live without it.

And night and day, we are bombarded incessantly by even higher-energy gamma-radiation photons from outer-space. There’s no protection from those, short of hiding in a mine shaft a mile deep.

What do lower-energy photons such as visible light, infrared light and microwave radiation do when they are absorbed by your body? They aren’t ionizing radiation. They don’t have enough energy to break apart molecules. They just get absorbed, and their energy converted into heat (the first law of thermodynamics). They make you warm. A lot of microwave photons, like in a microwave oven, will make you a lot of warm. And that’s just about it.

But then, this whole thing seems like a perfect example of what today’s Dilbert is about.

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