Cedar Rapids public library flooding

Library Journal interviews Marie DeVries of the Cedar Rapids Public Library. There's some good discussion of how one deals with a disaster like this.

"How’s it going?" "This is all fluid" was, I think, entirely unself-conscious.

(via librarian.net)

Guantanamo (yet) again

"US asks to rewrite detainee evidence"

"The government has stood behind the evidence for years. Military review boards relied on it to justify holding hundreds of prisoners indefinitely without charge. Justice Department attorneys said it was thoroughly and fairly reviewed.

Now that federal judges are about to review the evidence, however, the government says it needs to make changes."

No, not to redact potentially sensitive information, but to make the case more convincing than it was going to be if reviewed by military tribunals. Is anyone surprised?

Guarding guns

This is an interesting photo:

I was struck by the effort that someone has gone to keep all these weapons in neat rows and columns, rather than throw them into a compact pile. I may be missing something, but the only reason for it that comes to mind is the need to guard against black market trading. With everything in a neat row, it's harder for the guards or anyone else to snatch a few weapons without it being noticeable. A practical example of how our perception works: no one would notice a hundred rifles missing from a big messy pile, but if you mess up a nice row & column pattern, the gap would be too obvious to overlook.

Lincoln Museum closing in Fort Wayne

Somewhat old news that I haven't commented on: The old Lincoln Museum in Fort Wayne will close and the Lincoln Financial Foundation will seek new quarters for the collection, which happens to be the largest privately-owned collection of Lincoln materials in the world. The folks in Fort Wayne are no happier than you might expect them to be and are trying to find a way to keep the collection in Indiana at least.

If you discount the importance of Hoosier prestige, though, it's hard to see why the Lincoln Museum needs to stay in Indiana. The ACPL is probably one of the few community libraries that could actually take on such a project, but I don't think they have facilities and personnel already in place for this type of thing. I'm sure the ACPL and Indiana State Museum can do the job, but when Springfield or the Smithsonian already have high-level Lincoln collections, it'll be hard to compete. It's also hard to see a winning argument in the claim that keeping Lincoln materials geographically scattered is some kind of aid to researchers (although it is a defense against floods, fires, and the like).

Mechanical computers

I've been spending a bit more time than I can justify playing Silent Hunter III, a PC game that simulates WWII U-boat warfare. I'm enjoying a chance to relearn some of the trigonometry that I know, but forget I know. For example, "Ship sighted!" I'm headed due east, the target's on bearing 330 from me (ahead left), but I'm viewing them from an angle of 135 degrees on the starboard side (behind right, from their perspective). I need to get ahead of them, so what course do I command in order to run parallel to the ship while I overtake her? "Jawohl, Herr Kaleun! New course einz - null - fuenf!" Once I reach attack position, I need to be able to calculate an interception course of about 90 degrees for optimum firing position.

But you don't have to be lined up perfectly, although it's easier that way. You just have to make the torpedo travel on an angle that will intercept a moving target. What I never appreciated from watching Das Boot is that the submarine carried a sophisticated mechanical computer for aiming the computers. Remember how the commander always calls out the target's course, speed, and range? One of his crew is setting those numbers into the TDC - Torpedo Data Computer. But that's not quite enough information. We know what the target is doing now, but we haven't told the crewman whether the target is to the left, the right, dead ahead, or just where. Ah, we don't have to! The TDC knows because it has a connection to the periscope and knows which way it's turned (relative to the sub's bow). So once you've entered the target's range, course, and speed, the TDC will recalculate the firing solution as it detects the periscope's angle changing; the commander can now aim just by pointing the periscope at his target, regardless of which way his submarine is pointing. The TDC has been updating the setting of a gyroscope in the torpedo itself. Once the torpedo is launched, the gyroscope will keep the torpedo turning until it feels itself lined up with the angle the TDC wanted for it.

The fascinating part of this is that it was all done mechanically; this is years before ENIAC, let alone Commodore. For a sense of what it took to create a mechanical calculator like this, take a look at the American Mark 3 from the same era:



Pretty complicated, huh? All analog and, needless to say, highly classified. No doubt it was extremely expensive, too. This one could even track the target's movements (and compensate for the submarine's motion) in real time, which made it even more advanced than the German computer. And those poor guys in WWI had to do the same thing with a slide rule.

Speaking of which, there are some really hard core sub gamers out there who love doing things the hard way. They want to calculate the target's course manually, measure the angle to the mast to determine the range (have to know what ship you're looking at, so you know how tall the mast actually is), and use a stopwatch to determine the ship's speed. And they just love trying to recreate old targeting aids like this:

It's kind of like a WWII version of SCA - where else do you find guys eager to learn how a slide rule is used?