Wednesday, December 8, 2010

What are the odds?

It was one of those days. Yes, one of those days. Every now and then I have a day where it feels like I'm walking through a poorly dubbed Japanese movie. It's as if the movement of the lips doesn't match the audio track. Well, metaphorically anyway. Nothing seems to go quite right, and it's hard to get in the concentrative mode that I need to be in to do my technical work. I usually keep some simplistic office work in the bullpen for days like these, but I can't afford to lose the momentum I have on my latest big project so I just had to muddle on through. There will inevitably come a day a few months from now when a user has reported a problem and I come across some of the work I did today. I refer to those as "what was I thinking???" moments.

I did manage to do one thing right, though. I've spent the last few evenings working on the family Christmas letter, an annual duty that I somehow picked up a decade ago and now hate with a livid streak of red-tinged passion. It's a multi-day struggle to try to fit interesting news from the last year into a single page without it sounding like a laundry list of brags. If I don't get it just right, it runs the risk of being a postal version of that most irritating of bumper stickers: "My Child is an Honor Student," to which I always append the implied between-the-lines message "and Yours Isn't." People reportedly like the letters, but I don't find them very fulfilling to write. It's almost a preview of the even more dreaded tax season where I again have to dryly report arcane details in a rote manner. And in the same way, fighting against it is futile. It's a duty, and I do it. There really aren't that many demands on my domestic time, if I were to be truthful, but I still reserve the right to grouse about it.

After a few evenings of dabbling at the annual missive, it was finally done and only needed printing. Unfortunately my printer at home has been slacking off when it comes to the left two inches of the page, and a new toner cartridge had not fixed the problem. I carried the special paper to work this morning in order to print the letters on an old hand-me-down printer I have in my office. With that done, the only thing that could go wrong would be to leave the stack of letters at work. I carefully placed them in a folder by my jacket so I wouldn't forget them. And there they still sat after I came back up from the parking lot to get them, having realized at the last second before leaving for home that I hadn't brought them with me.

After a frustrating drive home, I was proud of my having accomplished the annual duty as I handed the stack of nicely printed letters over to my overseer. Within seconds she found a typo at the end of the second paragraph. Perfect. A fitting end to a frustrating day that had raised my irritation level to a few degrees over the boiling point already.

Despite that, I debated on whether or not I should go out to the hangar to see if I could make a little progress on the airplane. I hadn't been for a few days and the weather was close enough to tolerable at 30F and lots of sun, but it doesn't always work out so well when I try to work on the plane when my brain isn't fully engaged. I remembered that the next steps were fairly easy assembly jobs, so I thought I'd go on out and see how it went.

The parts were easy to find on the parts shelf and were small enough that the brittle blue plastic came off without putting up much of a battle.


These are the brackets that will support the flaperon hinges. Most of the holes have to remain open for later attachment to the wing. I clecoed a barrier of clecos across the line separating the okay-to-rivet area from the don't-rivet-here-unless-you-want-to-get-really-mad area.


The remaining eight holes on each assembly were to get AN470AD4-4 solid rivets squeezed into them, but not in any kind of specified order. No, they had to go in using a random order, presumably to spread the loads around to prevent warping the brackets with uneven stresses. The thing is, "random" is not really the word they wanted here. They really meant something along the lines of "a varied pattern." The problem is that people don't really understand the concept of randomness. Allow me to share an anecdote that demonstrates this misunderstanding.

Years ago when I worked at Compuserve, the people that were drawn to software development were of an almost universal Spock-like nature. We loved logic. We understood logic, and we understood concepts like randomness. In short, we were all geeks. One night we were over at a friend's house when his wife sent the friend's brother out to buy lottery tickets. He returned with tickets with number selections like '5, 10, 15, 20, 25, 20' and '1, 2, 3, 4, 5, 6'. The wife was livid!! She shouted at him, "You wasted my money! What are the odds of those numbers coming up???"

That was absolutely the wrong thing to say in front of a room full of computer geeks. She didn't understand the outburst of raucous laughter until someone explained to her that the odds of those numbers coming up was exactly the same as the odds of any other numbers coming up. In a truly random selection, there is no difference at all between a series of incrementing integers and a sporadic selection of numbers.

So, here's my point. I could have lined those rivets up in a straight line because that ordering would be every bit as random as any other.


I didn't, though.


I even got into the spirit of the thing and made an attempt at actual randomness.


See what I mean about having gone through the day slightly off kilter? My ear warmer thingy is on upside-down.

The assemblies seem to have come out of it okay. They now get set aside until section 16.


Oddly enough, I was feeling a lot better by that time. It was getting dark, though, and I was getting pretty cold. The sun was setting and a couple of Fahrenheits had slipped away when I wasn't looking. I knew it was getting cold when small wisps of steam would puff up when I squeezed a rivet quickly. I was surprised by that, by the way. The first few times I thought that I must be imagining it, but I watched closely a couple of times and sure enough, when I'd squeeze the rivet quickly it would heat up enough to throw off a little puff of smoke. I don't understand how that's happening - it's not like there's any moisture in a rivet to be released as steam - but I'm sure I saw it. Very odd.

1 comment:

leon said...

man that was one of the best examples of the folly of playing the lottery i have ever heard. thanks. also why still have an annual news letter when you blog so well.

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