Archive for September, 2008

enter the gPhone

Tuesday, September 23rd, 2008

Apple vs. Microsoft in the PC space turned out pretty well for consumers, but it sure did take a while.  Apple vs. Google in the phone space should bring improvements really, really quickly.

sometimes intuition can kill you

Saturday, September 20th, 2008

My regular flight instructor had to deal with some car trouble last thursday, so I flew with this other guy.  We talked a bit about aerodynamics before we went up, and he mentioned something counterintuitive / interesting / tragic about dive-bombers in WWII.

We lost a whole lot of them, which in itself isn’t shocking, but what’s odd is why we lost so many.

The problem wasn’t that:

  • They exceeded the do-not-exceed speed of the airframe, ripped it apart, and crashed.
  • They were usually headed directly into a hail of high-caliber and/or incendiary ammunition, which riddled / ignited the aircraft and subsequently caused structural failure / more crashing.
  • They misjudged their altitude and biffed the target / ocean / ground.

Despite the fact that a dive is the single highest-speed maneuver one can perform in an airplane, the problem was often that they aerodynamically stalled the aircraft while trying to exit the dive.

One of the “flying 101″ definitions that gets drilled into your head is that a stall will occur at any speed, and any gross weight if the angle of attack (the acute angle formed by the wing chord line and the relative wind) exceeds some critical upper limit (ie - the critical angle of attack).

That law makes all kinds of intuitive sense when you consider a plane flying horizontally, then pitching up to exceed the critical angle of attack.  The relative wind in that case is parallel to the earth’s surface, which feels natural.  But it somehow becomes much less intuitive when you consider a plane flying straight down, then pitching relatively-up toward the horizontal plane.  The relative wind in that case is headed straight up, “out of the Earth”-ward.  Irrelevant rationalizations enter your mind, like “he’s still going so fast, and there’s gotta be more relative wind coming from the right, yeah?”  Negative.  The law doesn’t care what direction you’re traveling in, or where the Earth is.  You exceed the critical angle of attack, you stall.

So there you are, some poor bastard in a 1940s-era warbird, hurtling toward Earth and well-armed enemy at somewhere near the speed of God, and you survive long enough to drop your bomb.  “Whew,” you think, “time to GTFO” and jerk back the stick to stop pointing at the ship, the thousands of rounds being fired at you, and the Earth.  Suddenly the controls get all mushy, and just like that you’re no longer hurtling forward, hands first toward the ground at insane speed, but tumbling down, ass first at nearly the same speed.  You can’t see it, but you know it’s coming.

Shitty.

The positive take-away, though, is that a combination of independent study and supervised training under controlled circumstances can allow a man to win battle after battle against unintuitive and potentially dangerous branches of scientific truth.

LOL

Monday, September 15th, 2008

One last Scheneir hat-tip post for the day.  Read this: http://www.schneier.com/blog/archives/2008/09/secret_military.html

…then marvel at the high-quality snark in the comments.  A frothy blend of deadpan humor and real insight.

profiling and terrorism

Monday, September 15th, 2008

Apolitical statement #1: In any large, high-complexity search space where time and resources are limited, you’re just not going to cover the space without using heuristics to guide the search.

Apolitical statement #2: In a nutshell, the heuristic-based search for terrorists is (and was always going to be) problematic because:

  • heuristics *always* miss
  • heuristics that are good at hitting positives tend to be kind of shitty at missing negatives, and vice versa
  • misses on positives (subject X was a terrorist that the search did not identify) and hits on negatives (subject X was misidentified as a terrorist) both really, really suck

There’s a rich an interesting philosophical/political debate to be had over whether we should, as a society, prefer to implement a search that fails in one direction or the other (failing to identify subjects who subsequently harm innocent people, or harming innocent people ourselves).  But that’s not really what I came here to talk about.

I came to say that when we actually get more *information* about what heuristics are likely to work, and what heuristics are unlikely to work, we should (at least temporarily) set aside our positions in the philosophical/political debate to absorb findings that *could* advance the state of the search science.

Link: MI5 released some interesting study results the other day (via CryptoGram).

self-exposure to retainable information

Monday, September 15th, 2008

I wouldn’t say I “studied” for the FAA written test this past weekend, per se, but I watched a lot of digital videos to prepare for some of the final stages of my private pilot training.  Short field / soft field techniques, medical information related to flying, radio navigation, night flying, preparing / filing / executing VFR flight plans, using the E6B “flight computer” (slide rule), weight and balance calculations, obtaining and making sense of various types of weather briefings, and a LOT about weather itself.  Good times.

at the clothes wash…whoa-oh-whoa-oh-whoa-oh at the clothes wash yeah

Monday, September 15th, 2008

First, a big heart-felt thank you to my mom’s friends, who pitched in to help Erica and I enter the exclusive club of washer and dryer ownership.  Now part 1 of a related saga.

Previous 3 weeks: looking forward to Saturday delivery of our new appliances.

Thursday night: call from delivery peeps confirming delivery for “tomorrow”; Erica calling back but getting an odd and non-committal response to change plans; FC calling and getting ahold of someone less surly and more informed.

Saturday morning at 8am: doorbell; FC and delivery guy looking skeptically at rear basement hatch; refusing delivery of dented dryer (with full support of delivery guys, who gave me a hotline to the right person at Lowe’s to get things straightened out with no additional hassle); looking on amazed as the guys got the washer through the hatch, installed, and tested in under 10 minutes.

Sunday morning: heard the truck pull up, two more nice delivery guys with undented dryer.  More skeptical looking at the rear basement hatch, but the dryer went in with millimeters to spare.  Moving straps FTW.  No additional 30-amp outlet OR dryer exhaust port in the basement, so no full install/test yet.

Today: getting in touch with building maintenance dude to see when the power and exhaust situation can get rectified, since our original punchlist had “washer/dryer hookups” plainly specified and agreed-to.

In other “less need for quarters” news, I picked up an EZPass on our way back from Utica last weekend, and am surprised at the qualitative quality-of-life improvement.  I didn’t realize how much energy I was throwing away worrying about keeping cash for pike tolls in the car, and this morning I actually used my cup holder to hold…a cup of iced coffee.

unsupervised

Wednesday, September 10th, 2008

Had my first unsupervised solo on Monday night; second scheduled for tomorrow morning.  The checklists are the same, the plane is the same, the airfield is the same, but there are qualitatively weighty differences at the edges.

For example: In the supervised case, even when the student is running the checklists, the instructor is ultimately responsible for ensuring that the initial step from “aircraft parked” to “aircraft not parked” is made safely and in accordance with all laws and policy.  From an OSHA standpoint, a Cessna is sort of like a lawnmower on its side with no blade guard, blades extended by two feet in both directions, raised to chest level, on wheels, with the motor swapped for something 50-100x as powerful.  It’s with some gravity that one cranes his neck around and yells “clear prop!” out the window before turning the key on that monster.

And like, when the plane is back on the ground and you’re back at the ramp…where *exactly* is one supposed to park?

flight, again

Wednesday, September 3rd, 2008

Now cleared for unsupervised solos in the pattern.  Time to turn up the gas on studying for / passing the written test.