Wednesday, December 06, 2006

Tom Swift and his radio death ray.

Wired News brings us an article about a new microwave weapon that causes extreme pain in those unfortunates at whom the 94 GHz beam is aimed. What the electromagnetic energy does to the people it's aimed at, is to cause heating just below the surface of the skin and hence a good deal of pain. The Air Force calls it the Active Denial System which sounds more like the White House’s public relations strategy, but the weapon is designed to disperse large groups of people in a hurry. Using beams of radio frequency energy as a weapon was postulated as early as the 1920’s but the technology to do so practically is a bit more recent.

Contrary to the garbled explanation Wired gives for the effect, it’s the super high frequency of the W band microwaves that prevent the energy from penetrating deep into body tissues as would happen with emissions in the 23 Cm / 1240 MHz L band that will boil your eyeballs or the 2400 MHz S band used in microwave ovens that will heat the water in the food you cook or in your body, should you chance to walk in front of a strong enough beam. One of the problems in microwave propagation in these frequencies is that the energy is too readily absorbed by the atmosphere, or water in the atmosphere. The 94 GHz radiation used in the weapon however, while it penetrates the atmosphere far better than frequencies on either side of it, does not seem to penetrate body tissues. It is an order of magnitude higher in frequency, but is a long, long, long way from infra-red much less the X-rays mentioned in the article.

There is some controversy over the possible dangers and unexpected consequences of this kind of weapon. I have seen no discussion of problems caused by reflection of the energy away from the intended path where it could affect bystanders – or be reflected back at the weapon itself. Apparently it has only been tested on groups of volunteer military personnel, which probably do not include the very young or the very old or infirm, but I’m sure it has its uses. Non-lethal weapons do have their place.

I have to wonder however, if maintaining an unpopular occupation or a colonial presence is one of those uses. One commenter mentioned that if the British had had this in the late 1940’s India might still be a colony – or perhaps would have had to resort to more than non-violent resistance to achieve independence. South Africa might still have Apartheid and the US might still have segregation. There are situations where a weapon like this could produce more violence.

We live in a country where Posse Comitatus has been done away with and I have to wonder if a power mad President could be tempted to use such a weapon against huge demonstrations and protests – after all, it’s non-lethal – as casually as and far more effectively than they have used tear gas and night sticks and water cannons to deprive us of yet another guaranteed right.

Sleep well

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