Tuesday, June 22, 2010

Old but not obsolete

kw: history, education

Several news items recently discussed the case of thirteen Marines in leadership training who were caught cheating and discharged from the Marines. They had used the prior year's answers to the rally point identifiers in a navigation exercise. While their poor ethics are sufficient to make them unsuitable military leaders, they were also stupid. Any wise instructor will change the test answers from year to year or session to session.

I was intrigued by a point someone made, that they thought the exercise was futile because of modern navigation aids such as GPS. They considered the compass-and-pace methods they were learning were obsolete. Let me simply ask: suppose a low-yield nuclear device is detonated anywhere within a few hundred miles of your position? Do you know the result? Your GPS device will burn out; it is, after all, a very sensitive radio receiver, and the giant electromagnetic pulse from the blast will run right down the antenna and fry the innards. A side note to civilians: three properly placed one-megaton blasts, set off at an altitude of 80+ km, will destroy nearly all the electronics of any kind in the entire United States (lower 48).

So what technological device will still work after a nuclear battlefield attack? A compass (but give it an hour or so for the electromagnetic disturbances to die away). Then those "obsolete" skills learned in leadership training will be your lifeline. And by the way, don't talk to me about "militarily hardened" GPS units. There ain't enough hardening available in a 100-gram package to protect the transistors connected to the antenna. Besides, the attack itself just might blow out some of the satellites that GPS depends on; how hardened are they? Hmmm?

A couple dozen years ago as I was finishing graduate school, my major professor learned that I am an amateur radio operator, and he told this story: He had, two years earlier, been on the Glomar Challenger, the deep-sea drilling ship used for geophysical research. One day, when their "shopping list" was due to be sent to the next port, there was a solar flare. Radio communications on most bands were wiped out, and it was expected that radio disturbances would last a few days.

It so happens that Morse Code communications are about 100 times as "penetrating" as voice communications, and perhaps ten times as penetrating as radioteletype (RTTY), the usual backup. The ship's radio operator could not get through either with voice or RTTY, so he transmitted the information using Morse Code with a hand key, at 20 words per minute or so.

There is nothing like having an "obsolete" skill at your fingertips when the "modern" ones cannot be used.

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